A key question in developmental biology is how cells exchange positional information for proper patterning during organ development. In plant roots the radial tissue organization is highly conserved with a central vascular cylinder in which two water conducting cell types, protoxylem and metaxylem, are patterned centripetally. We show that this patterning occurs through crosstalk between the vascular cylinder and the surrounding endodermis mediated by cell-to-cell movement of a transcription factor in one direction and microRNAs in the other. SHORT ROOT, produced in the vascular cylinder, moves into the endodermis to activate SCARECROW. Together these transcription factors activate MIR165a and MIR166b. Endodermally produced microRNA165/6 then acts to degrade its target mRNAs encoding class III homeodomain-leucine zipper transcription factors in the endodermis and stele periphery. The resulting differential distribution
Alzheimer's disease (AD) and stroke are common disorders of aging, but the relationship between these two disorders remains uncertain. Recent evidence recognized that they frequently co-occur and are influenced by each other, while other studies have produced inconsistent results. We conducted this systematic review and meta-analysis of stroke on risk for AD and AD on risk for stroke subtypes to clarify the relation between these two disorders on the basis of the studies published from 1975 to November 2013 in the PubMed, EMBASE, and Cochrane Library databases. In total, 7 cohort studies and 2 nested case-control studies met the inclusion criteria for meta-analysis. For stroke, the pooled effect size for AD risk was 1.59 (95% CI 1.25-2.02; z = 3.76; p = 0.000). For AD dementia, it was not associated with risk of all strokes or ischemic stroke (IS), but the risk of intracerebral hemorrhage (ICH was higher among persons with AD. The pooled RR for AD in relation to incident IS did not indicate a significant association (RR: 1.13; 95% CI 0.75-1.70; z = 0.58; p = 0.565). The pooled effect size for AD and ICH risk was 1.41 (95% CI 1.21-1.66; z = 4.27; p < 0.001). Stroke significantly and independently increased risk for AD and in turn AD increased risk for ICH. These results confirm that AD and ICH may have common pathogenesis and share preventive treatment measures.
The immune infiltration of tumors is closely related to clinical outcomes. The composition of tumor-infiltrating immune cells (TIICs) can serve as biomarkers for predicting response to treatment and survival in different patient subgroups in terms of chemotherapy and immunotherapy. This study is focused on investigating the clinical implications of TIICs in breast cancer patients. We performed several in silico analyses of gene expression profiles in 2976 nonmetastatic tumor samples. CIBERSORT was used to estimate the proportion of 22 immune cell types to analyze their correlation with overall survival (OS) and disease-free survival (DFS) in different breast cancer subtypes and stages. Our results showed that a higher fraction of plasma cells in estrogen receptor (ER)-positive breast cancer patients indicated an increase in DFS (hazard ratio [HR]=0.66, 95% confidence interval [CI] 0.54~0.82, p<0.01), while a decreased OS was correlated with a greater number of M0 macrophages (HR=2.02, 95% CI 1.27~3.30, p=0.01) and regulatory T cells (HR=1.90, 95% CI 1.20~3.02, p=0.02). In ER-negative or progesterone receptor (PR)-negative subtypes or in a combined subtype, the increase in activated memory CD4 + T cells was correlated with increased DFS (HR=0.46, 95% CI 0.33~0.63, p<0.01). In all breast cancer patients, a higher proportion of M0 macrophages indicated a decreased DFS (HR=1.67, 95% CI 1.22~2.27, p<0.01), while increased OS was associated with relatively larger fractions of resting memory CD4 + T cells (HR=0.70, 95% CI 0.55~0.90, p=0.02) and γδ T cells (HR=0.66, 95% CI 0.51~0.85, p<0.01). Therefore, this study revealed that the composition of TIICs is different in patients with various subtypes of breast cancer and is directly related to prognosis, suggesting that TIICs are important participants in tumor progression and may, potentially be used for future diagnosis and treatment.
The xylem and phloem, major conducting and supporting tissues in vascular plants, are established by cell division and celltype specification in the procambium/cambium. The organization of the xylem, phloem, and procambium/cambium is tightly controlled. However, the underlying regulatory mechanisms remain largely unknown. In this study, we report the discovery of two transcription factors, AT-HOOK MOTIF NUCLEAR LOCALIZED PROTEIN 3 (AHL3) and AHL4, which regulate vascular tissue boundaries in Arabidopsis thaliana roots. In either of the knockout mutants of AHL3 and AHL4, encoding closely related AT-hook transcription factors, a misspecification of tissue boundaries between the xylem and procambium occurred and ectopic xylem developed in the procambium domain. In plants, specific types of transcription factors can serve as direct intercellular signals by moving from one cell to another, playing crucial roles in tissue patterning. Adding to this paradigm, AHL4 moves actively from the procambium to xylem in the root meristem to regulate the tissue boundaries. When the intercellular movement of AHL4 was impaired, AHL4 could not complement the xylem phenotype in the ahl4. Furthermore, AHL4 revealed unique characteristics in that it interacts with AHL3 in vivo and that this interaction facilitates their intercellular trafficking. Taken together, this study uncovered a novel mechanism in vascular tissue patterning that requires the intercellular trafficking of two interacting transcription factors.
Participants in the intervention group were more successful performing certain simulated procedures than controls when tested immediately after receiving the curriculum but demonstrated declining skills thereafter. Future efforts must emphasize retraining, and residents must have sufficient opportunities to practice skills learned in a formal curriculum.
Thyroid disorders have emerged as one of the most common immune-related adverse events (irAE), yet optimum management and biomarkers to predict vulnerable individuals remain to be explored. High-dose glucocorticoid (HDG) therapy is routinely recommended for irAEs. However, systematic analysis of the impact of glucocorticoid therapy on the outcome of immune-checkpoint inhibitor (ICI)-induced thyroid disorders is lacking. We analyzed 151 patients with or without ICI-related thyroid disorders. We divided the patients with ICI-related thyroid disorders into two subgroups: those with and without HDG treatment. Our results showed no significant differences between HDG and no HDG groups in terms of the median duration of thyrotoxicosis: 28 (range, 7-85) and 42 (range, 14-273) days, the median time to conversion from thyrotoxicosis to hypothyroidism: 39 days (range, 14-169) and 42 days (range, 14-315) days, the median time to onset of hypothyroidism: 63 (range, 21-190) and 63 (range, 14-489) days, and the median maintenance dose of levothyroxine: 1.5 (range, 0.4-2.3) mg/kg/day, and 1.3 (range, 0.3-2.5) mg/kg/day. The median pretreatment TSH was 2.3 (range, 0.3-5.2) mIU/L and 1.7 (range, 0.5-4.5) mIU/L in patients with and without ICI-related thyroid disorders, respectively. Baseline TSH was significantly higher in patients who developed ICI-related thyroid disorders (P ¼ 0.05). Subgroup analysis revealed significantly higher baseline TSH in male but not in female patients with ICI-induced thyroid dysfunction. Our results show that HDG treatment did not improve the outcome of ICI-related thyroid disorders.
Cetuximab and panitumumab are monoclonal antibodies (mAbs) against epidermal growth factor receptor (EGFR) that are effective agents for metastatic colorectal cancer (mCRC). Cetuximab can prolong survival by 8.2 months in RAS wild-type (WT) mCRC patients. Unfortunately, resistance to targeted therapy impairs clinical use and efficiency. The mechanisms of resistance refer to intrinsic and extrinsic alterations of tumours. Multiple therapeutic strategies have been investigated extensively to overcome resistance to anti-EGFR mAbs. The intrinsic mechanisms include EGFR ligand overexpression, EGFR alteration, RAS/RAF/PI3K gene mutations, ERBB2/MET/IGF-1R activation, metabolic remodelling, microsatellite instability and autophagy. For intrinsic mechanisms, therapies mainly cover the following: new EGFR-targeted inhibitors, a combination of multitargeted inhibitors, and metabolic regulators. In addition, new cytotoxic drugs and small molecule compounds increase the efficiency of cetuximab. Extrinsic alterations mainly disrupt the tumour microenvironment, specifically immune cells, cancer-associated fibroblasts (CAFs) and angiogenesis. The directions include the modification or activation of immune cells and suppression of CAFs and anti-VEGFR agents. In this review, we focus on the mechanisms of resistance to anti-EGFR monoclonal antibodies (anti-EGFR mAbs) and discuss diverse approaches to reverse resistance to this therapy in hopes of identifying more mCRC treatment possibilities.
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