Molecular subtypes of oropharyngeal cancer show distinct immune microenvironment related with immune checkpoint blockade response.

BACKGROUND: Oropharyngeal cancer (OPC) exhibits diverse immunological properties; however, their implications for immunotherapy are unknown. METHODS: We analysed 37 surgically resected and nine recurrent or metastatic anti-programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1)-treated OPC tumours. OPCs were classified into immune-rich (IR), mesenchymal (MS) and xenobiotic (XB) subtypes based on RNA-sequencing data. RESULTS: All IR type tumours were human papillomavirus (HPV) positive, most XB types were HPV negative, and MS types showed mixed HPV status. The IR type showed an enriched T cell exhaustion signature with PD-1+ CD8+ T cells and type I macrophages infiltrating the tumour nest on multiplex immunohistochemistry. The MS type showed an exclusion of CD8+ T cells from the tumour nest and high MS and tumour growth factor-ß signatures. The XB type showed scant CD8+ T cell infiltration and focal CD73 expression. The IR type was associated with a favourable response signature during anti-PD-1/PD-L1 therapy and showed a high APOBEC mutation signature, whereas the MS and XB types showed resistance signature upregulation. Among anti-PD-1/PD-L1-treated OPC patients, the IR type showed a favourable clinical response (3/4 patients), whereas the XB type showed early progression (3/3 patients). CONCLUSION: Our analysis classified OPCs into three subtypes with distinct immune microenvironments that are potentially related to the response to anti-PD-1/PD-L1 therapy.

Correction: Molecular subtypes of oropharyngeal cancer show distinct immune microenvironment related with immune checkpoint blockade response.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Differences in the Efficacies of Pazopanib and Gemcitabine/Docetaxel as Second-Line Treatments for Metastatic Soft Tissue Sarcoma.

BACKGROUND: We retrospectively investigated the treatment outcomes of second-line treatment with pazopanib or gemcitabine/docetaxel in patients with advanced soft tissue sarcoma (STS). METHODS: Ninety-one patients who were treated with pazopanib or gemcitabine/docetaxel for advanced STS between 1995 and 2015 were analyzed. RESULTS: Forty-six and 45 patients received pazopanib and gemcitabine/docetaxel, respectively. The median progression-free survival for the group treated with pazopanib was 4.5 months compared with 3.0 months for the gemcitabine/docetaxel group (p = 0.593). The median overall survival for the group treated with pazopanib was 12.6 months compared with 14.2 months for the gemcitabine/docetaxel group (p = 0.362). The overall response rates (ORRs) were 6.5 and 26.7% in the pazopanib and gemcitabine/docetaxel groups, respectively. The following parameters had ORRs favoring gemcitabine/docetaxel: age ≥50 years (31.6 vs. 2.9%, p = 0.006), histologic grade 1-2 (40.9 vs. 0%, p = 0.001), and poor first-line treatment response (23.3 vs. 3.0%, p = 0.022). Gemcitabine/docetaxel was associated with better ORRs for the following histologic subtypes: leiomyosarcoma (p = 0.624), malignant fibrous histiocytoma/undifferentiated pleomorphic sarcoma (p = 0.055), and angiosarcoma (p = 0.182). However, the ORR of synovial sarcoma favored pazopanib (p = 0.99). CONCLUSIONS: The efficacies of pazopanib and gemcitabine/docetaxel as second-line treatments after doxorubicin or ifosfamide failure differed among clinical and histologic subgroups and appeared to facilitate a more personalized treatment approach for advanced STS.

Marked Loss of Muscle, Visceral Fat, or Subcutaneous Fat After Gastrectomy Predicts Poor Survival in Advanced Gastric Cancer: Single-Center Study from the CLASSIC Trial.

BACKGROUND: There is increasing interest in the influence of body composition on oncological outcomes. We evaluated the role of skeletal muscle and fat among patients with gastric cancer (GC) who underwent gastrectomy with or without adjuvant chemotherapy, as well as those changes' associations with survival outcomes. METHODS: The present study evaluated 136 patients with GC who were enrolled in the CLASSIC Trial at Yonsei Cancer Center. Baseline body compositions including skeletal muscle area, Hounsfield units (HU), visceral fat area, and subcutaneous fat area were measured by preoperative computed tomography (CT). CT before and after the gastrectomy were used to determine the 6-month relative changes in body composition parameters. Continuous variables were dichotomized according to the best cutoff values by Contal and O'Quigley method. RESULTS: Seventy-three patients (53.7%) underwent surgery alone, and 63 patients (46.3%) underwent surgery followed by adjuvant chemotherapy. The baseline body composition parameters were not associated with disease-free survival (DFS) or overall survival (OS). Except for the HU, the marked loss of muscle, visceral fat, or subcutaneous fat significantly predicted shorter DFS and OS. Patients with a marked loss in at least one significant body composition parameter had significantly shorter DFS (hazard ratio 2.9, 95% confidence interval 1.7-4.8, P < 0.001) and OS (hazard ratio 2.9, 95% confidence interval 1.7-5.0, P < 0.001). CONCLUSIONS: Marked loss in body composition parameters significantly predicted shorter DFS and OS among patients with GC who underwent gastrectomy. Postoperative nutrition and active healthcare interventions could improve the prognosis of these GC patients.

Microstructural heterogeneity directs micromechanics and mechanobiology in native and engineered fibrocartilage.

Treatment strategies to address pathologies of fibrocartilaginous tissue are in part limited by an incomplete understanding of structure-function relationships in these load-bearing tissues. There is therefore a pressing need to develop micro-engineered tissue platforms that can recreate the highly inhomogeneous tissue microstructures that are known to influence mechanotransductive processes in normal and diseased tissue. Here, we report the quantification of proteoglycan-rich microdomains in developing, ageing and diseased fibrocartilaginous tissues, and the impact of these microdomains on endogenous cell responses to physiologic deformation within a native-tissue context. We also developed a method to generate heterogeneous tissue-engineered constructs (hetTECs) with non-fibrous proteoglycan-rich microdomains engineered into the fibrous structure, and show that these hetTECs match the microstructural, micromechanical and mechanobiological benchmarks of native tissue. Our tissue-engineered platform should facilitate the study of the mechanobiology of developing, homeostatic, degenerating and regenerating fibrous tissues.

Preoperative Serum Carcinoembryonic Antigen Level as a Prognostic Factor for Recurrence and Survival After Curative Resection Followed by Adjuvant Chemotherapy in Stage III Colon Cancer.

BACKGROUND: Carcinoembryonic antigen (CEA) is the most widely used tumor marker in colon cancer; however, there has been controversy regarding the significance of preoperative serum CEA level as a prognostic factor for recurrence. In this study, we evaluated the optimal cutoff value and prognostic significance of preoperative serum CEA level in stage III colon cancer. METHODS: Based on a retrospective cohort of 965 patients with stage III colon cancer who underwent elective curative surgery and adjuvant chemotherapy with fluoropyrimidine and oxaliplatin (training set), we determined the optimal cutoff value of CEA for recurrence using the Contal and O'Quigley method. We assessed the prognostic value of this cutoff value in terms of disease-free survival (DFS) and overall survival (OS) in a prospective cohort of 268 patients with stage III colon cancer (validation set). A Cox proportional hazards model was used to explore the association of prognostic variables with DFS and OS. RESULTS: The statistically determined best cutoff value for CEA was 3 ng/mL in the training set. A high CEA level (≥3 ng/mL) was associated with inferior DFS (hazard ratio [HR] 4.609, 95 % confidence interval [CI] 2.028-10.474) and OS (HR 3.956, 95 % CI 1.127-13.882) in the validation set, while multivariate analysis showed that a high CEA level was an independent risk factor for DFS and OS in both study subsets. CONCLUSION: Preoperative serum CEA level is an independent prognostic factor for DFS and OS in patients with stage III colon cancer after curative resection and adjuvant chemotherapy.

Role of adjuvant chemotherapy in locally advanced rectal cancer with ypT0-3N0 after preoperative chemoradiation therapy and surgery.

BACKGROUND: We aimed to explore the clinical benefit of adjuvant chemotherapy (AC) with fluoropyrimidine in patients with ypT0-3N0 rectal cancer after preoperative chemoradiation therapy (CRT) followed by total mesorectal excision (TME). METHODS: Patients with ypT0-3N0 rectal cancer after preoperative CRT and TME were included using prospectively collected tumor registry cohort between January 2001 and December 2013. Patients were categorized into two groups according to the receipt of AC. Disease-free survival (DFS) and overall survival (OS) were compared between the adjuvant and observation groups. To control for potential confounding factors, we also calculated propensity scores and performed propensity score-matched analysis for DFS and OS. RESULTS: Of the 339 evaluated patients, 87 patients (25.7%) did not receive AC. There were no differences in DFS (hazard ratio [HR], 0.921; 95% confidence interval [CI], 0.562-1.507; P = 0.742) and OS (HR, 0.835; 95% CI, 0.423-1.648; P = 0.603) between the adjuvant and observation groups. After propensity score matching, DFS (HR, 1.129; 95% CI, 0.626-2.035; P = 0.688) and OS (HR, 1.200; 95% CI, 0.539-2.669; P = 0.655) did not differ between the adjuvant and observation groups. Advanced T stage and positive resection margin were independently associated with inferior DFS and OS on multivariate analysis. CONCLUSIONS: AC did not improve DFS and OS for patients with ypT0-3N0 rectal cancer after preoperative CRT followed by TME in this cohort study. The confirmative role of AC in locally advanced rectal cancer should be evaluated in prospective randomized trials with a larger sample size.

Mechanically Induced Chromatin Condensation Requires Cellular Contractility in Mesenchymal Stem Cells.

Mechanical cues play important roles in directing the lineage commitment of mesenchymal stem cells (MSCs). In this study, we explored the molecular mechanisms by which dynamic tensile loading (DL) regulates chromatin organization in this cell type. Our previous findings indicated that the application of DL elicited a rapid increase in chromatin condensation through purinergic signaling mediated by ATP. Here, we show that the rate and degree of condensation depends on the frequency and duration of mechanical loading, and that ATP release requires actomyosin-based cellular contractility. Increases in baseline cellular contractility via the addition of an activator of G-protein coupled receptors (lysophosphatidic acid) induced rapid ATP release, resulting in chromatin condensation independent of loading. Conversely, inhibition of contractility through pretreatment with either a RhoA/Rock inhibitor (Y27632) or MLCK inhibitor (ML7) abrogated ATP release in response to DL, blocking load-induced chromatin condensation. With loading, ATP release occurred very rapidly (within the first 10-20 s), whereas changes in chromatin occurred at a later time point (∼10 min), suggesting a downstream biochemical pathway mediating this process. When cells were pretreated with blockers of the transforming growth factor (TGF) superfamily, purinergic signaling in response to DL was also eliminated. Further analysis showed that this pretreatment decreased contractility, implicating activity in the TGF pathway in the establishment of the baseline contractile state of MSCs (in the absence of exogenous ligands). These data indicate that chromatin condensation in response to DL is regulated through the interplay between purinergic and RhoA/Rock signaling, and that ligandless activity in the TGF/bone morphogenetic proteins signaling pathway contributes to the establishment of baseline contractility in MSCs.

Effects of microsatellite instability on recurrence patterns and outcomes in colorectal cancers.

BACKGROUND: Among colorectal cancers (CRCs), high-frequency microsatellite instability (MSI-H) is associated with a better prognosis, compared with low-frequency MSI or microsatellite stability (MSI-L/MSS). However, it is unclear whether MSI affects the prognosis of recurrent CRCs. METHODS: This study included 2940 patients with stage I-III CRC who underwent complete resection. The associations of MSI status with recurrence patterns, disease-free survival (DFS), overall survival from diagnosis to death (OS1), and overall survival from recurrence to death (OS2) were analysed. RESULTS: A total of 261 patients (8.9%) had MSI-H CRC. Patients with MSI-H CRC had better DFS, compared to patients with MSI-L/MSS CRC (hazard ratio (HR): 0.619, P<0.001). High-frequency microsatellite instability CRC was associated with more frequent local recurrence (30.0% vs 12.0%, P=0.032) or peritoneal metastasis (40.0% vs 12.3%, P=0.003), and less frequent lung (10.0% vs 42.5%, P=0.004) or liver metastases (15.0% vs 44.7%, P=0.01). Recurrent MSI-H CRC was associated with worse OS1 (HR: 1.363, P=0.035) and OS2 (HR: 2.667, P<0.001). An analysis of patients with colon cancer yielded similar results. CONCLUSIONS: Recurrence patterns differed between MSI-H CRC and MSI-L/MSS CRC, and recurrent MSI-H CRCs had a worse prognosis.

Cumulative Metformin Use and Its Impact on Survival in Gastric Cancer Patients After Gastrectomy.

OBJECTIVE: The aim of this study was to evaluate the association between metformin and survival of gastric cancer (GC) patients. BACKGROUND: Metformin has recently received attention as a potential anticancer treatment. However, no study has shown the survival benefit of metformin for GC patients. METHODS: A total of 1974 GC patients who underwent curative gastrectomy were compared for survival according to groups; 132 diabetic patients treated with metformin, 194 diabetic patients without metformin, and 1648 non-diabetic patients. RESULTS: During the median follow-up period of 6.2 years (interquartile range, 4.7-7.8 years), 381 patients (19.3%) died, including 302 (15.3%) who died from GC. The non-diabetic patients had significantly better recurrence-free survival (RFS; P < 0.0001), cancer-specific survival (CSS; P = 0.006), and overall survival (OS; P < 0.0001). However, the diabetic patients treated with metformin had a significantly better prognosis than those who were not (OS: hazard ratio [HR] = 0.584, 95% confidence interval [CI], 0.369-0.926; CSS: HR = 0.57, 95% CI, 0.334-0.975; RFS: HR = 0.633, 95% CI, 0.410-0.977), and metformin treatment prolonged survival in diabetic patients to a rate comparable to that in non-diabetic patients. In multivariable analysis using the Cox proportional hazard model with time-dependent covariates, each cumulative 6 months of metformin use was significantly associated with a decreased risk of recurrence, cancer-specific mortality, and all-cause mortality (RFS: HR = 0.864, 95% CI, 0.797-0.937; CSS: HR = 0.865, 95% CI, 0.782-0.958; OS: HR 0.870, 95% CI, 0.801-0.945). CONCLUSIONS: The increased cumulative duration of metformin use decreased the recurrence, all-cause mortality, and cancer-specific mortality rates among GC patients with diabetes who underwent gastrectomy.

Benefit of Adjuvant Chemotherapy After Curative Resection of Lung Metastasis in Colorectal Cancer.

BACKGROUND: The survival benefit of adjuvant chemotherapy after colorectal cancer (CRC) lung metastasectomy is uncertain. METHODS: We enrolled 221 CRC patients who underwent pulmonary metastasectomy between October 2002 and July 2013, including those with previous liver metastasis that had been curatively resected. Disease-free survival (DFS) and overall survival (OS) were calculated from the day of lung metastasectomy. RESULTS: Among all patients, 176 (79.6%) received adjuvant chemotherapy after lung metastasectomy. Median follow-up was 34.7 months from the time of lung metastasectomy [95% confidence interval (95% CI), 7.4-90.9 months]. Patients treated with adjuvant chemotherapy had longer DFS compared with surgery alone (median 32.7 vs 11.2 months respectively, P = 0.076). Multivariate analysis revealed previous liver metastasis, preoperative carcinoembryonic antigen ≥5 ng/mL, disease-free interval <24 months, and surgery without adjuvant chemotherapy as independent risk factors for recurrence. Low-risk patients who had 0-1 risk factors received a significant survival benefit from adjuvant chemotherapy [hazard ratio (HR) 0.54; 95% CI 0.32-0.91, P = 0.020]; however, high-risk patients with ≥2 risk factors did not (HR 1.02; 95% CI 0.48-2.14, P = 0.964). Patients treated with adjuvant chemotherapy showed no OS benefit compared with patients who received surgery alone (median 89.6 vs 86.8 months respectively, P = 0.833). CONCLUSIONS: CRC patients received lung metastasectomy could have a DFS benefit from adjuvant chemotherapy, especially in low-risk patients. Larger, prospective studies are needed to evaluate the role of adjuvant chemotherapy after CRC lung metastasectomy.

Shear stress and circumferential stretch by pulsatile flow direct vascular endothelial lineage commitment of mesenchymal stem cells in engineered blood vessels.

Understanding the response of mesenchymal stem cells (MSCs) in the dynamic biomechanical vascular environment is important for vascular regeneration. Native vessel biomechanical stimulation in vitro is thought to be the most important contributor to successful endothelial differentiation of MSCs. However, the appropriate biomechanical stimulation conditions for differentiating MSCs into ECs have not been fully investigated. To accomplish an in vivo-like loading environment, a loading system was designed to apply flow induced stress and induce hMSC differentiation in vascular cells. Culturing MSCs on tubular scaffolds under flow-induced shear stress (2.5 dyne/cm(2)) for 4 days results in increased mRNA levels of EC markers (vWF, CD31, VE-cadherin and E-selectin) after one day. Furthermore, we investigated the effects of 2.5 dyne/cm(2) shear stress followed by 3% circumferential stretch for 3 days, and an additional 5% circumferential stretch for 4 days on hMSC differentiation into ECs. EC marker protein levels showed a significant increase after applying 5% stretch, while SMC markers were not present at levels sufficient for detection. Our results demonstrate that the expression of several hMSC EC markers cultured on double-layered tubular scaffolds were upregulated at the mRNA and protein levels with the application of fluid shear stress and cyclic circumferential stretch.

Cytoskeletal to Nuclear Strain Transfer Regulates YAP Signaling in Mesenchymal Stem Cells.

Mechanical forces transduced to cells through the extracellular matrix are critical regulators of tissue development, growth, and homeostasis, and can play important roles in directing stem cell differentiation. In addition to force-sensing mechanisms that reside at the cell surface, there is growing evidence that forces transmitted through the cytoskeleton and to the nuclear envelope are important for mechanosensing, including activation of the Yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif (TAZ) pathway. Moreover, nuclear shape, mechanics, and deformability change with differentiation state and have been likewise implicated in force sensing and differentiation. However, the significance of force transfer to the nucleus through the mechanosensing cytoskeletal machinery in the regulation of mesenchymal stem cell mechanobiologic response remains unclear. Here we report that actomyosin-generated cytoskeletal tension regulates nuclear shape and force transmission through the cytoskeleton and demonstrate the differential short- and long-term response of mesenchymal stem cells to dynamic tensile loading based on the contractility state, the patency of the actin cytoskeleton, and the connections it makes with the nucleus. Specifically, we show that while some mechanoactive signaling pathways (e.g., ERK signaling) can be activated in the absence of nuclear strain transfer, cytoskeletal strain transfer to the nucleus is essential for activation of the YAP/TAZ pathway with stretch.

The Clinicopathologic Features and Prognostic Impact of ALK Positivity in Patients with Resected Gastric Cancer.

BACKGROUND: Rearrangement of ALK is an established driver aberration in lung cancer. Accordingly, this study attempted to determine the frequency and prognostic impact of ALK alterations in patients with surgically resected gastric cancer. METHODS: The study evaluated ALK alterations in whole tumor sections of 455 curatively resected gastric cancers via immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH). Any expression of ALK protein (1+, 2+, 3+ by IHC) was considered as evidence of ALK positivity (ALK+), and the relationship between ALK positivity and clinicopathologic parameters, including survival outcome, was analyzed. RESULTS: Of the 455 tumors, 38 (8.4 %) were ALK positive, as measured by IHC. Among the ALK+ patients, two displayed break-apart signals of 5 and 11 % on FISH, respectively. The ALK+ patients were younger (57 vs. 61 years; P = 0.02) and more likely to exhibit a signet ring cell component. Moreover, as ALK intensity measured by IHC increased, so did the proportion of signet ring cells in tumors (defined as ≥10 % of tumor cells; P = 0.02). In terms of survival outcome, the ALK+ patients displayed worse disease-free survival (DFS) and overall survival (OS) than the ALK- patients (P = 0.010 for DFS; P = 0.023 for OS). Multivariate analysis demonstrated that ALK+ gastric cancer patients were at an increased risk of recurrence and death after adjustment for sex, age, tumor location, stage, adjuvant chemotherapy, histology, and epidermal growth factor receptor 2 (HER2) positivity (P = 0.04 for DFS; P = 0.02 for OS). CONCLUSIONS: The findings showed ALK positivity to be an independent negative prognostic factor in surgically resected gastric cancers associated with signet ring cell histology.

Prediction of short- and long-term survival for advanced cancer patients after ICU admission.

BACKGROUND: Intensive care unit (ICU) admission of advanced cancer patients is controversial because it is associated with poor short-term prognosis. However, ICU admission of these patients might also result in administration of specific anticancer treatments and evaluation of tumor characteristics, which could influence long-term outcomes. Herein, we investigate whether there is a relationship between ICU admission and long-term outcomes for advanced cancer patients. METHODS: We analyzed 116 advanced cancer patients who were admitted to the ICU at Severance Hospital, Yonsei University, between January 2010 and December 2012. We excluded palliative care-only patients. We analyzed demographic, clinical, and survival data of patients admitted to the ICU, and we identified patient characteristics that were measured upon presentation to ICU to determine whether any of these are prognostic or predictive factors of short- or long-term survival. RESULTS: The median age of our study sample was 64 years. Sixty-nine (59.5 %) patients were male. Lung, breast, and stomach were the most common primary tumor sites. Eighty-seven (75 %) patients had received active anticancer treatment within the past 30 days. The main cause of ICU admission was acute respiratory failure (73 %); thus, 102 (87.9 %) patients were managed with conventional mechanical ventilation, 99 (85.3 %) patients in vasopressor and 31 (26.7 %) patients received continuous renal replacement therapy (CRRT). Twenty-four (20.7 %) patients were in postresuscitation status before ICU admission. The ICU, hospital, and 6-month survival rates were 51.7, 31.0, and 15.5 %, respectively. APACHE II score (HR 2.86, 95 % CI 1.00-8.15, P < 0.050) and need for CRRT (HR 2.14, 95 % CI 1.24-3.70, P < 0.007) were associated with ICU mortality in a Cox-regression model. Eastern Cooperative Oncology Group (ECOG) performance status (HR 1.64, 95 % CI 1.03-2.62, P < 0.010) was associated with poor prognosis, and controlled disease status (HR 0.372, 95 % CI 0.21-0.67, P < 0.001) was found to be a good prognostic factor for 6-month survival after ICU admission. CONCLUSIONS: Clinical factors associated with acute, critical status upon ICU admission, such as APACHE II score and need of CRRT, were associated with a higher risk of ICU mortality and short-term mortality than factors directly associated with the patient's cancer. To understand the relationship between ICU admission and long-term survival, however, we have to apply more comprehensive approach that also considers tumor characteristics and disease control status.

Low-Temperature Nanosecond Laser Process of HZO-IGZO FeFETs toward Monolithic 3D System on Chip Integration.

Ferroelectric field-effect transistors (FeFETs) are increasingly important for in-memory computing and monolithic 3D (M3D) integration in system-on-chip (SoC) applications. However, the high-temperature processing required by most ferroelectric memories can lead to thermal damage to the underlying device layers, which poses significant physical limitations for 3D integration processes. To solve this problem, the study proposes using a nanosecond pulsed laser for selective annealing of hafnia-based FeFETs, enabling precise control of heat penetration depth within thin films. Sufficient thermal energy is delivered to the IGZO oxide channel and HZO ferroelectric gate oxide without causing thermal damage to the bottom layer, which has a low transition temperature (<250 °C). Using optimized laser conditions, a fast response time (<1 µs) and excellent stability (cycle > 106, retention > 106 s) are achieved in the ferroelectric HZO film. The resulting FeFET exhibited a wide memory window (>1.7 V) with a high on/off ratio (>105). In addition, moderate ferroelectric properties (2·Pr of 14.7 µC cm-2) and pattern recognition rate-based linearity (potentiation: 1.13, depression: 1.6) are obtained. These results demonstrate compatibility in HZO FeFETs by specific laser annealing control and thin-film layer design for various structures (3D integrated, flexible) with neuromorphic applications.

Structure-Mechanics Principles and Mechanobiology of Fibrocartilage Pericellular Matrix: A Pivotal Role of Type V Collagen.

The pericellular matrix (PCM) is the immediate microniche surrounding resident cells in various tissue types, regulating matrix turnover, cell-matrix cross-talk and disease initiation. This study elucidated the structure-mechanical properties and mechanobiological functions of the PCM in fibrocartilage, a family of connective tissues that sustain complex tensile and compressive loads in vivo. Studying the murine meniscus as the model tissue, we showed that fibrocartilage PCM contains thinner, random collagen fibrillar networks that entrap proteoglycans, a structure distinct from the densely packed, highly aligned collagen fibers in the bulk extracellular matrix (ECM). In comparison to the ECM, the PCM has a lower modulus and greater isotropy, but similar relative viscoelastic properties. In Col5a1 +/- menisci, the reduction of collagen V, a minor collagen localized in the PCM, resulted in aberrant fibril thickening with increased heterogeneity. Consequently, the PCM exhibited a reduced modulus, loss of isotropy and faster viscoelastic relaxation. This disrupted PCM contributes to perturbed mechanotransduction of resident meniscal cells, as illustrated by reduced intracellular calcium signaling, as well as upregulated biosynthesis of lysyl oxidase and tenascin C. When cultured in vitro, Col5a1 +/- meniscal cells synthesized a weakened nascent PCM, which had inferior properties towards protecting resident cells against applied tensile stretch. These findings underscore the PCM as a distinctive microstructure that governs fibrocartilage mechanobiology, and highlight the pivotal role of collagen V in PCM function. Targeting the PCM or its molecular constituents holds promise for enhancing not only meniscus regeneration and osteoarthritis intervention, but also addressing diseases across various fibrocartilaginous tissues.

Macro- to microscale strain transfer in fibrous tissues is heterogeneous and tissue-specific.

Mechanical deformation applied at the joint or tissue level is transmitted through the macroscale extracellular matrix to the microscale local matrix, where it is transduced to cells within these tissues and modulates tissue growth, maintenance, and repair. The objective of this study was to investigate how applied tissue strain is transferred through the local matrix to the cell and nucleus in meniscus, tendon, and the annulus fibrosus, as well as in stem cell-seeded scaffolds engineered to reproduce the organized microstructure of these native tissues. To carry out this study, we developed a custom confocal microscope-mounted tensile testing device and simultaneously monitored strain across multiple length scales. Results showed that mean strain was heterogeneous and significantly attenuated, but coordinated, at the local matrix level in native tissues (35-70% strain attenuation). Conversely, freshly seeded scaffolds exhibited very direct and uniform strain transfer from the tissue to the local matrix level (15-25% strain attenuation). In addition, strain transfer from local matrix to cells and nuclei was dependent on fiber orientation and tissue type. Histological analysis suggested that different domains exist within these fibrous tissues, with most of the tissue being fibrous, characterized by an aligned collagen structure and elongated cells, and other regions being proteoglycan (PG)-rich, characterized by a dense accumulation of PGs and rounder cells. In meniscus, the observed heterogeneity in strain transfer correlated strongly with cellular morphology, where rounder cells located in PG-rich microdomains were shielded from deformation, while elongated cells in fibrous microdomains deformed readily. Collectively, these findings suggest that different tissues utilize distinct strain-attenuating mechanisms according to their unique structure and cellular phenotype, and these differences likely alter the local biologic response of such tissues and constructs in response to mechanical perturbation.

Risk factors and prognosis of pulmonary complications after endoscopic submucosal dissection for gastric neoplasia.

BACKGROUND: Hospital-acquired pneumonia after an endoscopic submucosal dissection (ESD) can prolong the patient's stay in the hospital, leading to greater healthcare costs. However, little is known of the characteristics and risk factors associated with this complication. AIMS: To analyze the clinical features of pneumonia after ESD and to suggest a treatment plan. METHODS: This was a retrospective study in which the cases of 1,661 consecutive patients who underwent ESD for 1,725 lesions between January 2008 and June 2011 were reviewed. RESULTS: Of the 1,661 patients who underwent ESD during the study period, 38 were subsequently diagnosed with pneumonia, and an additional 18 patients exhibited lung consolidation, based on chest radiography, without respiratory signs or symptoms. The remaining 1,605 patients showed neither lung consolidation on chest radiography nor respiratory signs/symptoms. Continuous propofol infusion with intermittent or continuous administration of an opioid [odds ratio (OR) 4.498, 95 % confidence interval (CI) 2.267-8.923], a procedure time of >2 h (OR 2.900, 95 % CI 1.307-6.439), male gender (OR 2.835, 95 % CI 1.164-6.909), and age >75 years (OR 2.765, 95 % CI 1.224-6.249) were independent risk factors for pneumonia after ESD. In patients with only lung consolidation (without respiratory signs and symptoms), the length of hospital stay and prognosis were not affected by antibiotics use. CONCLUSIONS: Deep sedation under continuous propofol infusion with opioid injection during ESD may be a risk factor for pneumonia.

Suspension bath bioprinting and maturation of anisotropic meniscal constructs.

Due to limited intrinsic healing capacity of the meniscus, meniscal injuries pose a significant clinical challenge. The most common method for treatment of damaged meniscal tissues, meniscectomy, leads to improper loading within the knee joint, which can increase the risk of osteoarthritis. Thus, there is a clinical need for the development of constructs for meniscal repair that better replicate meniscal tissue organization to improve load distributions and function over time. Advanced three-dimensional bioprinting technologies such as suspension bath bioprinting provide some key advantages, such as the ability to support the fabrication of complex structures using non-viscous bioinks. In this work, the suspension bath printing process is utilized to print anisotropic constructs with a unique bioink that contains embedded hydrogel fibers that align via shear stresses during printing. Constructs with and without fibers are printed and then cultured for up to 56 din vitroin a custom clamping system. Printed constructs with fibers demonstrate increased cell and collagen alignment, as well as enhanced tensile moduli when compared to constructs printed without fibers. This work advances the use of biofabrication to develop anisotropic constructs that can be utilized for the repair of meniscal tissue.