Mesenchymal stem cell-derived extracellular vesicles in skin wound healing:roles,opportunities and challenges

Skin wounds are characterized by injury to the skin due to trauma,tearing,cuts,or contusions.As such injuries are common to all human groups,they may at times represent a serious socioeconomic burden.Currently,increasing numbers of studies have focused on the role of mesenchymal stem cell(MSC)-derived extracellular vesicles(EVs)in skin wound repair.As a cell-free therapy,MSC-derived EVs have shown significant application potential in the field of wound repair as a more stable and safer option than conventional cell therapy.Treatment based on MSC-derived EVs can significantly promote the repair of damaged substructures,including the regeneration of vessels,nerves,and hair follicles.In addition,MSC-derived EVs can inhibit scar formation by affecting angiogenesis-related and antifibrotic pathways in promoting macrophage polarization,wound angiogenesis,cell proliferation,and cell migration,and by inhibiting excessive extracellular matrix production.Additionally,these structures can serve as a scaffold for components used in wound repair,and they can be developed into bioengineered EVs to support trauma repair.Through the formulation of standardized culture,isolation,purification,and drug delivery strategies,exploration of the detailed mechanism of EVs will allow them to be used as clinical treatments for wound repair.In conclusion,MSCderived EV-based therapies have important application prospects in wound repair.Here we provide a comprehensive overview of their current status,application potential,and associated drawbacks.

Assessment of correlation between serum titers of hepatitis c virus and severity of liver disease

AIM:The significance of hepatitis C virus (HCV) serum titers has been examined in several clinical situations. There is much evidence that patients with a lower viral load have better response rates to anti-viral therapy compared to those with higher levels.Moreover,a direct association has been observed between serum titers of HCV and transmission rates of the virus.The aim of the present study was to determine if there was any correlation between HCV viral load and the severity of liver disease. METHODS:Fifty patients with HCV infection were included in the study.These comprised of 34 subjects with a history of alcohol use and 16 non-alcoholics.Quantitative serum HCV RNA assay was carried out using the branched DNA (bDNA) technique.Linear regression analysis was performed between serum viral titers and liver tests.In addition,for the purpose of comparison,the subjects were divided into two groups:those with low viral liters (≤50 genome mEq/mL) and high titers (>50 mEq/mL). RESULTS:All subjects were men,with a mean±SD age of 47±7.8 years.The mean HCV RNA level in the blood was 76.3×10~5±109.1 genome equivalents/mL.There was no correlation between HCV RNA levels and age of the patients (r=0.181),and the history or amount (g/d) of alcohol consumption (r=0.07).Furthermore,no correlation was observed between serum HCV RNA levels and the severity of liver disease as judged by the values of serum albumin (r=0.175),bilirubin (r=0.217),ALT (r=0.06) and AST (r=0.004) levels.Similarly,no significant difference was observed between patients with low viral titers and high liters with respect to any of the parameters. CONCLUSION:Our results indicate that the severity of liver disease is independent of serum levels of hepatitis C virus.These findings are important since they have a direct impact on the current debate regarding the role of direct cytopathic effect of hepatitis C virus versus immune-mediated injury in the pathogenesis of HCV-related liver damage.

奈妥匹坦帕洛诺司琼预防化疗引起的恶心呕吐:从临床试验到日常临床实践

化疗引起的恶心呕吐(CINV)是众多抗癌药物治疗中常见的不良事件,不仅会对患者生活质量带来负面影响,还有可能影响化疗效果。目前,指南建议的止吐方案可以预防大部分癌症患者的CINV。但临床医师并不能始终遵循指南建议,患者也常常难以坚持医师处方的治疗。因此需要采取一些提高指南依从性的方法。奈妥匹坦帕洛诺司琼(NEPA)是首个也是唯一一个固定剂量复方止吐药,由奈妥匹坦(口服)/福奈妥匹坦(静脉给药)与帕洛诺司琼(PALO)组成。NEPA可以联合地塞米松组成三联止吐方案,这是用于高致吐性化疗(HEC)患者和部分中致吐性化疗(MEC)患者预防CINV的推荐方案。因此,NEPA止吐治疗操作简单便捷,可能有助于提高指南依从性。本综述对CINV进行了概括,评价了在临床试验和真实实践中积累的NEPA止吐效果及安全性方面的证据,同时也评价了在关键临床试验之外的环境下,即日常临床环境中使用NEPA进行止吐的初步证据。此外,本文还评述了化疗期间使用NEPA控制恶心症状和提高患者生活质量,这是癌症患者管理中面临的两个大挑战。

Vitamin D deficiency in cirrhosis relates to liver dysfunction rather than aetiology

AIM: To examine the vitamin D status in patients with alcoholic cirrhosis compared to those with primary biliary cirrhosis. METHODS: Our retrospective case series comprised 89 patients with alcoholic cirrhosis and 34 patients with primary biliary cirrhosis who visited our outpatient clinic in 2005 and underwent a serum vitamin D status assessment. RESULTS: Among the patients with alcoholic cirrhosis, 85% had serum vitamin D levels below 50 nmol/L and 55% had levels below 25 nmol/L, as compared to 60% and 16% of the patients with primary biliary cirrhosis, respectively (P < 0.001). In both groups, serum vitamin D levels decreased with increasing liver disease severity, as determined by the Child-Pugh score. CONCLUSION: Vitamin D deficiency in cirrhosis relates to liver dysfunction rather than aetiology, with lower levels of vitamin D in alcoholic cirrhosis than in primary biliary cirrhosis.

Treatment of Budd-Chiari syndrome with a focus on transjugular intrahepatic portosystemic shunt

AIM:To evaluate long-term complications and survival in patients with Budd-Chiari syndrome (BCS) referred to a Danish transjugular intrahepatic portosystemic shunt (TIPS) centre.METHODS:Twenty-one consecutive patients from 1997-2008 were retrospectively included [15 women and 6 men,median age 40 years (range 17-66 years)].Eighteen Danish patients came from the 1.8 million catchment population of Aarhus University Hospital and three patients were referred from Scandinavian hospitals.Management consisted of tests for underlying haematological,endocrinological,or hypercoagulative disorders parallel to initiation of specific treatment of BCS.RESULTS:BCS was mainly caused by thrombophilic (33%) or myeloproliferative (19%) disorders.Fortythree percents had symptoms for less than one week with ascites as the most prevalent finding.Fourteen (67%) were treated with TIPS and 7 (33%) were manageable with treatment of the underlying condition and diuretics.The median follow-up time for the TIPS-treated patients was 50 mo (range 15-117 mo),and none required subsequent liver transplantation.Ascites control was achieved in all TIPS patients with a marked reduction in the dose of diuretics.A total of 14 TIPS revisions were needed,mostly of uncovered stents.Two died during follow-up:One non-TIPS patient worsened after 6 mo and died in relation to transplantation,and one TIPS patient died 4 years after the TIPS-procedure,unrelated to BCS.CONCLUSION:In our BCS cohort TIPS-treated patients have near-complete survival,reduced need for diuretics and compared to historical data a reduced need for liver transplantation.

Protein tolerance to standard and high protein meals in patients with liver cirrhosis

To investigate the plasma amino acid response and tolerance to normal or high protein meals in patients with cirrhosis. METHODSThe plasma amino acid response to a 20 g mixed protein meal was compared in 8 biopsy-proven compensated cirrhotic patients and 6 healthy subjects. In addition the response to a high protein meal (1 g/kg body weight) was studied in 6 decompensated biopsy-proven cirrhotics in order to evaluate their protein tolerance and the likelihood of developing hepatic encephalopathy (HE) following a porto-caval shunt procedure. To test for covert HE, the “number connection test” (NCT) was done on all patients, and an electroencephalogram was recorded in patients considered to be at Child-Pugh C stage. RESULTSThe changes in plasma amino acids after a 20 g protein meal were similar in healthy subjects and in cirrhotics except for a significantly greater increase (P < 0.05) in isoleucine, leucine and tyrosine concentrations in the cirrhotics. The baseline branched chain amino acids/aromatic amino acids (BCAA/AAA) ratio was higher in the healthy persons and remained stable-but it decreased significantly after the meal in the cirrhotic group. After the high protein meal there was a marked increase in the levels of most amino acids, but only small changes occurred in the levels of taurine, citrulline, cysteine and histidine.The BCAA/AAA ratio was significantly higher 180 and 240 min after the meal. Slightly elevated basal plasma ammonia levels showed no particular pattern. Overt HE was not observed in any patients. CONCLUSIONPatients with stable liver disease tolerate natural mixed meals with a standard protein content. The response to a high protein meal in decompensated cirrhotics suggests accumulation of some amino acids but it did not precipitate HE. These results support current nutritional guidelines that recommend a protein intake of 1.2-1.5 g/kg body weight/day for patients with cirrhosis.

Soluble membrane attack complex in ascites in patients with liver cirrhosis without infections

AIM: To study complement activation in 46 patients with alcoholic cirrhosis and ascites but no spontaneous bacterial peritonitis (SBP) and 10 healthy controls. METHODS: Complement activation was determined by the measurement of soluble membrane attack complex (sMAC) concentrations in ascites and plasma. In patients, metabolic liver function was determined by the galactose elimination capacity and the clinical status assessed by the Model of End-Stage Liver Disease and Child-Pugh scores. RESULTS: Ascites sMAC levels were markedly higherthan in the corresponding plasma sample (median (range): 596 (170 - 1519) vs 160 (77 - 848) μg/L; P < 0.01). Ascites sMAC levels correlated positively with liver status. There was no relationship between ascites sMAC and leukocyte count. No relationship between ascites sMAC and blood C-reactive protein, albumin or neutrophile count was found. Plasma sMAC concentrations were slightly higher in patients than in controls [130 μg/L (70 - 204); P = 0.04]. Neither sMAC in ascites nor plasma was related to mortality. CONCLUSION: The increased sMAC concentration in ascites and plasma indicate an activation of the complement system in cirrhosis even in the absence of SBP. This was particularly evident in the peritoneal fluid and most marked in patients with preserved liver status. The high ascites sMAC levels may reflect transudation of membrane attack complexes from the liver. Whether this complement activation has any clinical implications remains to be clarified.

Body composition changes after transjugular intrahepatic portosystemic shunt in patients with cirrhosis

AIM:To investigate the effect of transjugular intra-hepatic porto-systemic shunt (TIPS) on malnutrition in portal hypertensive cirrhotic patients.METHODS: Twenty-one patients with liver cirrhosis and clinical indications for TIPS insertion were investigated before and 1, 4, 12, 52 wk after TIPS. For each patient we assayed body composition parameters [dry lean mass, fat mass, total body water (TBW)], routine liver and kidney function tests, and free fatty acids (FFA). Glucose and insulin were measured for the calculation of the homeostasis model assessment insulin resistance (HOMA-IR); liver function was measured by the galactose elimination capacity (GEC); the severity of liver disease was graded by model for end-stage liver disease (MELD).RESULTS: Porto-systemic gradient decreased after TIPS (6.0±2.1 mmHg vs 15.8±4.8 mmHg, P<0.001). Patients were divided in two groups according to initial body mass index. After TIPS, normal weight patients had an increase in dry lean mass (from 10.9±5.9 kg to 12.7±5.6 kg, P=0.031) and TBW (from 34.5±7.6 L to 40.2±10.8 L,P=0.007), as well as insulin (from 88.9±49.2 pmol/L to 164.7±107.0 pmol/L,P=0.009) and HOMA-IR (from 3.36%±2.18% to 6.18%±4.82%,P=0.023). In overweight patients only FFA increased significantly (from 0.59±0.24 mmol/L to 0.93±0.34 mmol/L, P=0.023).CONCLUSION: TIPS procedure is effective in lowering portal pressure in patients with portal hypertension and improves body composition without significant changes in metabolic parameters.

PET测定肝硬化急性肝性脑病期间的^(13)N-氨在脑组织中的代谢状况

Animal studies and results from 13N-ammonia positron emission tomography (PET) in patients with cirrhosis and minimal hepatic encephalopathy suggest that a disturbed brain ammonia metabolism plays a pivotal role in the pathogenesis of hepatic encephalopathy (HE). We studied brain ammonia kinetics in 8 patients with cirrhosis with an acute episode of clinically overt HE (I-IV), 7 patients with cirrhosis without HE, and 5 healthy subjects, using contemporary dynamic 13N-ammonia PET. Time courses were obtained of 13N-concentrations in cerebral cortex, basal ganglia, and cerebellum (PET-scans) as well as arterial 13N-ammonia, 13N-urea, and 13N-glutamine concentrations (blood samples) after 13N-ammonia injection. Regional 13N-ammonia kinetics was calculated by non-linear fitting of a physiological model of brain ammonia metabolism to the data. Mean permeability-surface area product of 13N-ammonia transfer across blood-brain barrier in cortex, PSBBB was 0.21 mL blood/min/mL tissue in patients with HE, 0.31 in patients without HE, and 0.34 in healthy controls; similar differences were seen in basal ganglia and cerebellum. Metabolic trapping of blood 13N-ammonia in the brain showed neither regional, nor patient group differences. Mean net metabolic flux of ammonia from blood into intracellular glutamine in the cortex was 13.4 μmol/min/L tissue in patients with cirrhosis with HE, 7.4 in patients without HE, and 2.6 in healthy controls, significantly correlated to blood ammonia. In conclusion, increased cerebral trapping of ammonia in patients with cirrhosis with acute HE was primarily attributable to increased blood ammonia and to a minor extent to changed ammonia kinetics in the brain.

酒精性肝病患者补充镁剂和肌肉功能检测:一项随机、安慰剂、对照试验

Objective. The study was undertaken in order to evaluate the effect of magnesium (Mg) supplementation on muscle contents of Mg, muscle strength, muscle mass and sodium, potassium pumps (Na,K- pumps) in patients with alcoholic liver disease. Retrospectively, patients were also stratified according to spironolactone treatment. Material and methods. The study comprised a placebo- controlled, randomized trial in which 59 consecutive patients with alcoholic liver disease were treated with Mg intravenously and orally (12.5 mmol daily) or placebo for 6 weeks. Muscle content of Mg, maximum isokinetic muscle strength, skeletal muscle mass and muscle content of Na,K- pumps were measured before and after Mg supplementation. Results. Muscle Mg did not increase during the trial (paired t- test), but Mg supplementation and the duration of prestudy spironolactone treatment were independent predictors of muscle Mg (multiple regression). Muscle strength increased by 14% during the trial (p < 0.001) and muscle mass increased by 11% (p =.05), but with no difference between placebo and Mg treatment. Spironolactone treatment was associated with a 33% increase in the content of Na,K- pumps (p < 0.001). Conclusions. Six weeks of Mg supplementation did not increase muscle Mg, although Mg supplementation and spironolactone treatment were independent predictors of muscle Mg. The intervention had no effect on muscle strength and mass, but both increased during the study, probably owing to the general care and attendance to the patients.

Understanding myofibroblast origin in the fibrotic lung

Idiopathic pulmonary fibrosis(IPF)is characterized by accumulation of myofibroblasts(MYFs)and extracellular matrix components,which leads to severe distortion and scarring of the gas exchange units of the lung,the alveoli,and ultimately respiratory failure.Fibrosis-associated MYFs are therefore widely regarded as the culprits that compromise the architectural makeup of the lung in fibrotic disease.During the past decade,the cellular source of MYFs has been intensely investigated.The rationale for such studies is that identifying the origin of these cells might help identify novel therapeutic targets and candidates to treat IPF patients.Recent advances in basic and translational research employing lineage tracing and multi-omics approaches have helped address the identity of MYF precursors,highlight the underlying heterogeneity,and to a less extent investigate MYF fate during fibrosis resolution.In this review,we discuss the current understanding of such important aspects of MYF biology as well as recent developments in the treatment of IPF.