203 research outputs found
The Outcome of Complex Hepato-Pancreato-Biliary Surgery for Elderly Patients: A Propensity Score Matching Analysis
Background/Aims: Postoperative mortality and morbidity rates after hepato-pancreato-biliary (HPB) surgery remain high, and the number of elderly patients requiring such surgery has been increasing. This study aimed to investigate postoperative outcomes of complex HPB surgery for elderly patients. Methods: We retrospectively reviewed perioperative data of 721 patients who underwent complex HPB surgery between 2010 and 2015. The patients were divided into 2 groups: elderly (≥75 years) and non-elderly (< 75 years). Surgical outcomes of both groups were compared after propensity score-matching analysis. Subsequently, risk factors for serious postoperative morbidity were identified by multivariate analysis. Results: Before matching, the elderly group (n = 170) had more comorbidities, such as cardiovascular and renal disease, than the non-elderly group (n = 551). Matching yielded elderly (n = 170) and non-elderly groups (n = 170) with similar preoperative backgrounds. The mortality and morbidity rates did not differ significantly between the groups. In multivariate analyses, operative time (OR 1.79; p = 0.005) and blood loss (OR 1.66; p = 0.03) were identified as independent risk factors for serious postoperative morbidity, whereas older age did not have a predictive impact (OR 1.16; p = 0.52). Conclusions: Although elderly patients had more comorbidities and higher incidences of postoperative mortality and several complications before matching, their postoperative outcomes were equivalent to those of non-elderly patients after matching
Mutations in TGFbeta-RII and BAX mediate tumor progression in the later stages of colorectal cancer with microsatellite instability
Abstract Background Microsatellite instability (MSI) occurs in 15% of colorectal cancers (CRC). The genetic targets for mutation in the MSI phenotype include somatic mutations in the transforming growth factor beta receptor typeII (TGFbetaRII), BAX, hMSH3 and hMSH6. It is not clear how mutations of these genes mediate tumor progression in the MSI pathway, and the temporal sequence of these mutations remains uncertain. In this study, early stage CRCs were examined for frameshift mutations in these target genes, and compared with late stage tumors and CRC cell lines. Methods We investigated 6 CRC cell lines and 71 sporadic CRCs, including 61 early stage cancers and 10 late stage cancers. Mutations of repetitive mononucleotide tracts in the coding regions of TGFbetaRII, BAX, hMSH3, hMSH6, IGFIIR and Fas antigen were identified by direct sequencing. Results Thirteen (18.3%) of 71 CRC, including 9/61 (14.7%) early stage cancers and 4/10 (40%) late stage cancers, were identified as MSI and analyzed for frameshift mutations. No mutation in the target genes was observed in any of the 9 early stage MSI CRCs. In contrast, frameshift mutations of TGFbetaRII, BAX, hMSH3 and hMSH6 were present in 3/4 late stage MSI tumors. There is a statistical association (p = 0.014) between mutation in any one gene and tumor stage. Conclusions TGFbetaRII, BAX, hMSH3 and hMSH6 mutations are relatively late events in the genesis of MSI CRCs. The frameshift mutations in these target genes might mediate progression from early to late stage cancer, rather than mediating the adenoma to carcinoma transition.</p
Phosphorylated Smad2 in Advanced Stage Gastric Carcinoma
<p>Abstract</p> <p>Background</p> <p>Transforming growth factor β (TGFβ) receptor signaling is closely associated with the invasion ability of gastric cancer cells. Although Smad signal is a critical integrator of TGFβ receptor signaling transduction systems, not much is known about the role of Smad2 expression in gastric carcinoma. The aim of the current study is to clarify the role of phosphorylated Smad2 (p-Smad2) in gastric adenocarcinomas at advanced stages.</p> <p>Methods</p> <p>Immunohistochemical staining with anti-p-Smad2 was performed on paraffin-embedded specimens from 135 patients with advanced gastric adenocarcinomas. We also evaluated the relationship between the expression levels of p-Smad2 and clinicopathologic characteristics of patients with gastric adenocarcinomas.</p> <p>Results</p> <p>The p-Smad2 expression level was high in 63 (47%) of 135 gastric carcinomas. The p-Smad2 expression level was significantly higher in diffuse type carcinoma (p = 0.007), tumours with peritoneal metastasis (p = 0.017), and tumours with lymph node metastasis (p = 0.047). The prognosis for p-Smad2-high patients was significantly (p = 0.035, log-rank) poorer than that of p-Smad2-low patients, while a multivariate analysis revealed that p-Smad2 expression was not an independence prognostic factor.</p> <p>Conclusion</p> <p>The expression of p-Smad2 is associated with malignant phenotype and poor prognosis in patients with advanced gastric carcinoma.</p
Suppression of Osteosarcoma Cell Invasion by Chemotherapy Is Mediated by Urokinase Plasminogen Activator Activity via Up-Regulation of EGR1
Background: The cellular and molecular mechanisms of tumour response following chemotherapy are largely unknown. We
found that low dose anti-tumour agents up-regulate early growth response 1 (EGR1) expression. EGR1 is a member of the
immediate-early gene group of transcription factors which modulate transcription of multiple genes involved in cell
proliferation, differentiation, and development. It has been reported that EGR1 act as either tumour promoting factor or
suppressor. We therefore examined the expression and function of EGR1 in osteosarcoma.
Methods: We investigated the expression of EGR1 in human osteosarcoma cell lines and biopsy specimens. We next
examined the expression of EGR1 following anti-tumour agents treatment. To examine the function of EGR1 in
osteosarcoma, we assessed the tumour growth and invasion in vitro and in vivo.
Results: Real-time PCR revealed that EGR1 was down-regulated both in osteosarcoma cell lines and osteosarcoma patients’
biopsy specimens. In addition, EGR1 was up-regulated both in osteosarcoma patient’ specimens and osteosarcoma cell lines
following anti-tumour agent treatment. Although forced expression of EGR1 did not prevent osteosarcoma growth, forced
expression of EGR1 prevented osteosarcoma cell invasion in vitro. In addition, forced expression of EGR1 promoted downregulation
of urokinase plasminogen activator, urokinase receptor, and urokinase plasminogen activity. Xenograft mice
models showed that forced expression of EGR1 prevents osteosarcoma cell migration into blood vessels.
Conclusions: These findings suggest that although chemotherapy could not prevent osteosarcoma growth in
chemotherapy-resistant patients, it did prevent osteosarcoma cell invasion by down-regulation of urokinase plasminogen
activity via up-regulation of EGR1 during chemotherapy periods
Effect of dynamic compressive loading and its combination with a growth factor on the chondrocytic phenotype of 3-dimensional scaffold-embedded chondrocytes
Background and purpose Three-dimensionally (3D-) embedded chondrocytes have been suggested to maintain the chondrocytic phenotype. Furthermore, mechanical stress and growth factors have been found to be capable of enhancing cell proliferation and ECM synthesis. We investigated the effect of mechanical loading and growth factors on reactivation of the 3D-embedded chondrocytes
Seasonal variations in the nitrogen isotopic composition of settling particles at station K2 in the western subarctic North Pacific
Intensive observations using hydrographical cruises and moored sediment trap deployments during 2010 and 2012 at station K2 in the North Pacific western subarctic gyre (WSG) revealed seasonal changes in δ15N of both suspended and settling particles. Suspended particles (SUS) were collected from depths between the surface and 200 m; settling particles by drifting traps (DST; 100-200 m) and moored traps (MST; 200 and 500 m). All particles showed higher δ15N values in winter and lower in summer, contrary to the expected by isotopic fractionation during phytoplankton nitrate consumption. We suggest that these observed isotopic patterns are due to ammonium consumption via light-controlled nitrification, which could induce variations in δ15N(SUS) of 0.4-3.1 ‰ in the euphotic zone (EZ). The δ15N(SUS) signature was reflected by δ15 N(DST) despite modifications during biogenic transformation from suspended particles in the EZ. δ15 N enrichment (average: 3.6 ‰) and the increase in C:N ratio (by 1.6) in settling particles suggests year-round contributions of metabolites from herbivorous zooplankton as well as TEPs produced by diatoms. Accordingly, seasonal δ15 N(DST) variations of 2.4-7.0 ‰ showed a significant correlation with primary productivity (PP) at K2. By applying the observed δ15 N(DST) vs. PP regression to δ15 N(MST) of 1.9-8.0 ‰, we constructed the first annual time-series of PP changes in the WSG. Moreover, the monthly export ratio at 500 m was calculated using both estimated PP and measured organic carbon fluxes. Results suggest a 1.6 to 1.8 times more efficient transport of photosynthetically-fixed carbon to the intermediate layers occurs in summer/autumn rather than winter/spring
Effects of valproic acid on the cell cycle and apoptosis through acetylation of histone and tubulin in a scirrhous gastric cancer cell line
<p>Abstract</p> <p>Background</p> <p>Management of peritoneal dissemination is the most critical problem in gastric cancer. This study was performed to investigate the inhibitory effects of valproic acid (VPA) on a highly peritoneal-seeding cell line of human scirrhous gastric cancer, OCUM-2MD3, and to explore the mechanism and the potential of VPA.</p> <p>Methods</p> <p>The effects of VPA on the growth of OCUM-2MD3 cells were assessed by MTT assay. In addition, paclitaxel (PTX) was combined with VPA to evaluate their synergistic effects. HDAC1 and HDAC2 expression were evaluated by western blotting in OCUM-2MD3 cells and other gastric cancer cell lines (TMK-1, MKN-28). The acetylation status of histone H3 and α-tubulin after exposure to VPA were analyzed by western blotting. The activities of cell cycle regulatory proteins and apoptosis-modulating proteins were also examined by western blotting. The effects of VPA <it>in vivo </it>were evaluated in a xenograft model, and apoptotic activity was assessed by TUNEL assay.</p> <p>Results</p> <p>OCUM-2MD3 cells showed high levels of HDAC1 and HDAC2 expression compared with TMK-1 and MKN-28. The concentration of VPA required for significant inhibition of cell viability (<it>P </it>< 0.05) was 5 mM at 24 h and 0.5 mM at 48 h and 72 h. The inhibition of VPA with PTX showed dose-dependent and combinatorial effects. VPA increased acetyl-histone H3, acetyl-α-tubulin, and p21WAF1 levels accompanied by upregulation of p27, caspase 3, and caspase 9, and downregulation of bcl-2, cyclin D1, and survivin. In the xenograft model experiment, the mean tumor volume of the VPA-treated group was significantly reduced by 36.4%, compared with that of the control group at 4 weeks after treatment (<it>P </it>< 0.01). The apoptotic index was significantly higher in the VPA-treated group (42.3% ± 3.5%) than in the control group (7.7% ± 2.5%) (<it>P </it>< 0.001).</p> <p>Conclusions</p> <p>VPA induced dynamic modulation of histone H3 and α-tubulin acetylation in relation with the anticancer effect and the enhancement of PTX in the OCUM-2MD3 cell line. Therefore, VPA in combination with PTX is expected to be a promising therapy for peritoneal dissemination of scirrhous gastric cancer.</p
Changes in Striatal Dopamine Release Associated with Human Motor-Skill Acquisition
The acquisition of new motor skills is essential throughout daily life and involves the processes of learning new motor sequence and encoding elementary aspects of new movement. Although previous animal studies have suggested a functional importance for striatal dopamine release in the learning of new motor sequence, its role in encoding elementary aspects of new movement has not yet been investigated. To elucidate this, we investigated changes in striatal dopamine levels during initial skill-training (Day 1) compared with acquired conditions (Day 2) using 11C-raclopride positron-emission tomography. Ten volunteers learned to perform brisk contractions using their non-dominant left thumbs with the aid of visual feedback. On Day 1, the mean acceleration of each session was improved through repeated training sessions until performance neared asymptotic levels, while improved motor performance was retained from the beginning on Day 2. The 11C-raclopride binding potential (BP) in the right putamen was reduced during initial skill-training compared with under acquired conditions. Moreover, voxel-wise analysis revealed that 11C-raclopride BP was particularly reduced in the right antero-dorsal to the lateral part of the putamen. Based on findings from previous fMRI studies that show a gradual shift of activation within the striatum during the initial processing of motor learning, striatal dopamine may play a role in the dynamic cortico-striatal activation during encoding of new motor memory in skill acquisition
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