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BACKGROUND & AIMS: Guidelines recommend use of risk stratification scores for patients presenting with gastrointestinal bleeding (GIB) to identify very-low-risk patients eligible for discharge from emergency departments. Machine learning models may outperform existing scores and can be integrated within the electronic health record (EHR) to provide real-time risk assessment without manual data entry. We present the first EHR-based machine learning model for GIB. METHODS: The training cohort comprised 2546 patients and internal validation of 850 patients presenting with overt GIB (ie, hematemesis, melena, and hematochezia) to emergency departments of 2 hospitals from 2014 to 2019. External validation was performed on 926 patients presenting to a different hospital with the same EHR from 2014 to 2019. The primary outcome was a composite of red blood cell transfusion, hemostatic intervention (ie, endoscopic, interventional radiologic, or surgical), and 30-day all-cause mortality. We used structured data fields in the EHR, available within 4 hours of presentation, and compared the performance of machine learning models with current guideline-recommended risk scores, Glasgow-Blatchford Score, and Oakland Score. Primary analysis was area under the receiver operating characteristic curve. Secondary analysis was specificity at 99% sensitivity to assess the proportion of patients correctly identified as very low risk. RESULTS: The machine learning model outperformed the Glasgow-Blatchford Score (area under the receiver operating characteristic curve, 0.92 vs 0.89; P < .001) and Oakland Score (area under the receiver operating characteristic curve, 0.92 vs 0.89; P < .001). At the very-low-risk threshold of 99% sensitivity, the machine learning model identified more very-low-risk patients: 37.9% vs 18.5% for Glasgow-Blatchford Score and 11.7% for Oakland Score (P < .001 for both comparisons). CONCLUSIONS: An EHR-based machine learning model performs better than currently recommended clinical risk scores and identifies more very-low-risk patients eligible for discharge from the emergency department.
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Current histological measurement techniques for interstitial collagen, the basis of interstitial fibrosis, are semi-quantitative at best and only provide a ratio of collagen levels within tissues. The Genesis200 imaging system and supplemental image analysis software, FibroIndex from HistoIndex, is a novel, automated platform that uses second-harmonic generation (SHG) for imaging and characterization of interstitial collagen deposition and additional characteristics, in the absence of any staining. However, its ability to quantify renal fibrosis requires investigation. This study compared SHG imaging of renal fibrosis in mice with unilateral ureteric obstruction (UUO), to that of Masson's trichrome staining (MTS) and immunohistochemistry (IHC) of collagen I. Additionally, the platform generated data on collagen morphology and distribution patterns. While all three methods determined that UUO-injured mice underwent significantly increased renal fibrosis after 7 days, the HistoIndex platform additionally determined that UUO-injured mice had a significantly increased collagen-to-tissue cross reticulation ratio (all P < .001 vs sham group). Furthermore, in UUO-injured mice treated with the relaxin family peptide receptor-1 agonists, relaxin (0.5 mg/kg/day) or B7-33 (0.25 mg/kg/day), or angiotensin converting enzyme-inhibitor, perindopril (1 mg/kg/day) over the 7-day period, only the HistoIndex platform determined that the drug-induced prevention of renal fibrosis correlated with significantly reduced collagen fiber thickness and collagen-to-tissue cross reticulation ratio, but increased collagen fiber counts. Relaxin or B7-33 treatment also increased renal matrix metalloproteinase-2 and reduced tissue inhibitor of metalloproteinase-1 levels (all P < .01 vs UUO alone). This study demonstrated the diagnostic value of the HistoIndex platform over currently used staining techniques.
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Fibrose/patologia , Nefropatias/patologia , Fragmentos de Peptídeos/farmacologia , Relaxina/farmacologia , Obstrução Ureteral/complicações , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Fibrose/tratamento farmacológico , Fibrose/etiologia , Nefropatias/tratamento farmacológico , Nefropatias/etiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
BACKGROUND: Recombinant human relaxin-2 (serelaxin), which has organ-protective actions mediated via its cognate G protein-coupled receptor relaxin family peptide receptor 1 (RXFP1), has emerged as a potential agent to treat fibrosis. Studies have shown that serelaxin requires the angiotensin II (AngII) type 2 receptor (AT2R) to ameliorate renal fibrogenesis in vitro and in vivo. Whether its antifibrotic actions are affected by modulation of the AngII type 1 receptor (AT1R), which is expressed on myofibroblasts along with RXFP1 and AT2R, is unknown. METHODS: We examined the signal transduction mechanisms of serelaxin when applied to primary rat renal and human cardiac myofibroblasts in vitro, and in three models of renal- or cardiomyopathy-induced fibrosis in vivo. RESULTS: The AT1R blockers irbesartan and candesartan abrogated antifibrotic signal transduction of serelaxin via RXFP1 in vitro and in vivo. Candesartan also ameliorated serelaxin's antifibrotic actions in the left ventricle of mice with cardiomyopathy, indicating that candesartan's inhibitory effects were not confined to the kidney. We also demonstrated in a transfected cell system that serelaxin did not directly bind to AT1Rs but that constitutive AT1R-RXFP1 interactions could form. To potentially explain these findings, we also demonstrated that renal and cardiac myofibroblasts expressed all three receptors and that antagonists acting at each receptor directly or allosterically blocked the antifibrotic effects of either serelaxin or an AT2R agonist (compound 21). CONCLUSIONS: These findings have significant implications for the concomitant use of RXFP1 or AT2R agonists with AT1R blockers, and suggest that functional interactions between the three receptors on myofibroblasts may represent new targets for controlling fibrosis progression.
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Rim/patologia , Miocárdio/patologia , Miofibroblastos/fisiologia , Receptor Tipo 1 de Angiotensina/fisiologia , Receptor Tipo 2 de Angiotensina/fisiologia , Receptores Acoplados a Proteínas G/fisiologia , Receptores de Peptídeos/fisiologia , Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Animais , Benzimidazóis/uso terapêutico , Compostos de Bifenilo/uso terapêutico , Células Cultivadas , Fibrose , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Ratos Sprague-Dawley , Receptor Tipo 2 de Angiotensina/agonistas , Receptores Acoplados a Proteínas G/agonistas , Receptores de Peptídeos/agonistas , Proteínas Recombinantes , Relaxina/fisiologia , Tetrazóis/uso terapêuticoRESUMO
Current asthma therapies primarily target airway inflammation (AI) and suppress episodes of airway hyperresponsiveness (AHR) but fail to treat airway remodelling (AWR), which can develop independently of AI and contribute to irreversible airway obstruction. The present study compared the anti-remodelling and therapeutic efficacy of human bone marrow-derived mesenchymal stem cells (MSCs) to that of human amnion epithelial stem cells (AECs) in the setting of chronic allergic airways disease (AAD), in the absence or presence of an anti-fibrotic (serelaxin; RLX). Female Balb/c mice subjected to the 9-week model of ovalbumin (OVA)-induced chronic AAD, were either vehicle-treated (OVA alone) or treated with MSCs or AECs alone [intranasally (i.n.)-administered with 1×106 cells once weekly], RLX alone (i.n.-administered with 0.8 mg/ml daily) or a combination of MSCs or AECs and RLX from weeks 9-11 (n=6/group). Measures of AI, AWR and AHR were then assessed. OVA alone exacerbated AI, epithelial damage/thickness, sub-epithelial extracellular matrix (ECM) and total collagen deposition, markers of collagen turnover and AHR compared with that in saline-treated counterparts (all P<0.01 compared with saline-treated controls). RLX or AECs (but not MSCs) alone normalized epithelial thickness and partially diminished the OVA-induced fibrosis and AHR by â¼40-50% (all P<0.05 compared with OVA alone). Furthermore, the combination treatments normalized epithelial thickness, measures of fibrosis and AHR to that in normal mice, and significantly decreased AI. Although AECs alone demonstrated greater protection against the AAD-induced AI, AWR and AHR, compared with that of MSCs alone, combining RLX with MSCs or AECs reversed airway fibrosis and AHR to an even greater extent.
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Âmnio/citologia , Asma/terapia , Células Epiteliais/transplante , Receptores Acoplados a Proteínas G/genética , Receptores de Peptídeos/genética , Relaxina/administração & dosagem , Âmnio/metabolismo , Animais , Asma/tratamento farmacológico , Asma/imunologia , Modelos Animais de Doenças , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Feminino , Humanos , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Peptídeos/metabolismoRESUMO
BACKGROUND AND PURPOSE: Fibrosis is a hallmark of chronic kidney disease (CKD) that significantly contributes to renal dysfunction, and impairs the efficacy of stem cell-based therapies. This study determined whether combining bone marrow-derived mesenchymal stem cells (BM-MSCs) with the renoprotective effects of recombinant human relaxin (serelaxin) could therapeutically reduce renal fibrosis in mice with one kidney/deoxycorticosterone acetate/salt (1K/DOCA/salt)-induced hypertension, compared with the effects of the ACE inhibitor, perindopril. EXPERIMENTAL APPROACH: Adult male C57BL/6 mice were uni-nephrectomised and received deoxycorticosterone acetate and saline to drink (1K/DOCA/salt) for 21 days. Control mice were uni-nephrectomised but received water over the same time period. Sub-groups of 1K/DOCA/salt-injured mice (n = 5-8 per group) were treated with either serelaxin (0.5 mg·kg-1 ·day-1 ) or BM-MSCs (1 × 106 per mouse) alone; both treatments combined (with 0.5 × 106 or 1 × 106 BM-MSCs per mouse); or perindopril (2 mg·kg-1 ·day-1 ) from days 14-21. KEY RESULTS: 1K/DOCA/salt-injured mice developed elevated BP and hypertension-induced renal damage, inflammation and fibrosis. BM-MSCs alone reduced the injury-induced fibrosis and attenuated BP to a similar extent as perindopril. Serelaxin alone modestly reduced renal fibrosis and effectively reduced tubular injury. Strikingly, the combined effects of BM-MSCs (at both doses) with serelaxin significantly inhibited renal fibrosis and proximal tubular epithelial injury while restoring renal architecture, to a greater extent than either therapy alone, and over the effects of perindopril. CONCLUSION AND IMPLICATIONS: Combining BM-MSCs and serelaxin provided broader renoprotection over either therapy alone or perindopril and might represent a novel treatment for hypertensive CKD.
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Acetato de Desoxicorticosterona , Hipertensão Renal , Hipertensão , Células-Tronco Mesenquimais , Animais , Pressão Sanguínea , Desoxicorticosterona , Hipertensão/induzido quimicamente , Hipertensão/tratamento farmacológico , Rim , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
OBJECTIVE: Primarily to determine mid-term functional outcome for patients with distal radius fracture (DRF) and to compare this between operative and conservatively managed patients. Secondarily to examine for differences in age, gender and number of instability factors between management groups. METHODS: Eligible patients (age 18 years or more, closed DRF managed to completion of care within Monash Health), presenting between 1 January and 31 December 2016. Completion of the patient-rated wrist evaluation (PRWE) questionnaire was sought at 6-12 months post-injury. Management was noted (operative or conservative). Age, sex and number of defined instability factors present (dorsal angulation >20°, intra-articular fracture, associated ulna fracture, dorsal comminution, radial shortening >2 mm) are reported and compared between management groups. RESULTS: Of 369 eligible patients, 199 (54%) completed a PRWE. Median age was 60 years (interquartile range [IQR] 45-71), 150 (75%) were women, median number of instability factors present was 2 (IQR 1-4) and 45 (23%) underwent operative management. Difference in PRWE scores between operative and conservatively managed patients was not significant (20 [IQR 7-36] vs 16 [IQR 5-35]). Differences in age and gender between management groups were not significant. Significantly more in the operative group had presence of four or more instability factors (44% [95% confidence interval 30-60] vs 20% [14-27]). CONCLUSION: The mid-term median PRWE score was 18 (IQR 5-36). This was not significantly different between operative and conservatively managed patients. Operation was more likely when four or more instability factors were present.
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Fixação de Fratura/métodos , Fraturas do Rádio/terapia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recuperação de Função Fisiológica , Inquéritos e Questionários , Atenção Terciária à Saúde , VitóriaRESUMO
Fibrosis is involved in the majority of cardiovascular diseases and is a key contributor to end-organ dysfunction. In the current study, the antifibrotic effects of recombinant human relaxin-2 (serelaxin; RLX) and/or the AT2R agonist CGP42112 (CGP) were compared with those of the established AT1R antagonist, candesartan cilexetil (CAND), in a high salt-induced cardiac fibrosis model. High salt (HS; 5%) for 8 weeks did not increase systolic blood pressure in male FVB/N mice, but CAND treatment alone significantly reduced systolic blood pressure from HS-induced levels. HS significantly increased cardiac interstitial fibrosis, which was reduced by either RLX and/or CGP, which were not additive under the current experimental conditions, while CAND failed to reduce HS-induced cardiac fibrosis. The antifibrotic effects induced by RLX and/or CGP were associated with reduced myofibroblast differentiation. Additionally, all treatments inhibited the HS-induced elevation in tissue inhibitor of matrix metalloproteinases-1, together with trends for increased MMP-13 expression, that collectively would favor collagen degradation. Furthermore, these antifibrotic effects were associated with reduced cardiac inflammation. Collectively, these results highlight that either RXFP1 or AT2R stimulation represents novel therapeutic strategies to target fibrotic conditions, particularly in HS states that may be refractory to AT1R blockade.
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Fibrosis is associated with accumulation of excess fibrillar collagen, leading to tissue dysfunction. Numerous processes, including inflammation, myofibroblast activation, and endothelial-to-mesenchymal transition, play a role in the establishment and progression of fibrosis. Relaxin is a peptide hormone with well-known antifibrotic properties that result from its action on numerous cellular targets to reduce fibrosis. Relaxin activates multiple signal transduction pathways as a mechanism to suppress inflammation and myofibroblast activation in fibrosis. In this review, the general mechanisms underlying fibrotic diseases are described, along with the current state of knowledge regarding cellular targets of relaxin. Finally, an overview is presented summarizing the signaling pathways activated by relaxin and other relaxin family peptide receptor agonists to suppress fibrosis.
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Matriz Extracelular/metabolismo , Relaxina/metabolismo , Transdução de Sinais , Animais , Fibrose , Humanos , Miofibroblastos/metabolismo , Miofibroblastos/patologia , Óxido Nítrico/metabolismoRESUMO
This study determined if the anti-fibrotic drug, serelaxin (RLN), could augment human bone marrow-derived mesenchymal stem cell (MSC)-mediated reversal of airway remodeling and airway hyperresponsiveness (AHR) associated with chronic allergic airways disease (AAD/asthma). Female Balb/c mice subjected to the 9-week model of ovalbumin (OVA)-induced chronic AAD were either untreated or treated with MSCs alone, RLN alone or both combined from weeks 9-11. Changes in airway inflammation (AI), epithelial thickness, goblet cell metaplasia, transforming growth factor (TGF)-ß1 expression, myofibroblast differentiation, subepithelial and total lung collagen deposition, matrix metalloproteinase (MMP) expression, and AHR were then assessed. MSCs alone modestly reversed OVA-induced subepithelial and total collagen deposition, and increased MMP-9 levels above that induced by OVA alone (all p<0.05 vs OVA group). RLN alone more broadly reversed OVA-induced epithelial thickening, TGF-ß1 expression, myofibroblast differentiation, airway fibrosis and AHR (all p<0.05 vs OVA group). Combination treatment further reversed OVA-induced AI and airway/lung fibrosis compared to either treatment alone (all p<0.05 vs either treatment alone), and further increased MMP-9 levels. RLN appeared to enhance the therapeutic effects of MSCs in a chronic disease setting; most likely a consequence of the ability of RLN to limit TGF-ß1-induced matrix synthesis complemented by the MMP-promoting effects of MSCs.