NO Synthesis but Not Apoptosis, Mitosis or Inflammation Can Explain Correlations between Flow Directionality and Paracellular Permeability of Cultured Endothelium.

Haemodynamic wall shear stress varies from site to site within the arterial system and is thought to cause local variation in endothelial permeability to macromolecules. Our aim was to investigate mechanisms underlying the changes in paracellular permeability caused by different patterns of shear stress in long-term culture. We used the swirling well system and a substrate-binding tracer that permits visualisation of transport at the cellular level. Permeability increased in the centre of swirled wells, where flow is highly multidirectional, and decreased towards the edge, where flow is more uniaxial, compared to static controls. Overall, there was a reduction in permeability. There were also decreases in early- and late-stage apoptosis, proliferation and mitosis, and there were significant correlations between the first three and permeability when considering variation from the centre to the edge under flow. However, data from static controls did not fit the same relation, and a cell-by-cell analysis showed that <5% of uptake under shear was associated with each of these events. Nuclear translocation of NF-κB p65 increased and then decreased with the duration of applied shear, as did permeability, but the spatial correlation between them was not significant. Application of an NO synthase inhibitor abolished the overall decrease in permeability caused by chronic shear and the difference in permeability between the centre and the edge of the well. Hence, shear and paracellular permeability appear to be linked by NO synthesis and not by apoptosis, mitosis or inflammation. The effect was mediated by an increase in transport through tricellular junctions.

Visualization of three pathways for macromolecule transport across cultured endothelium and their modification by flow.

Transport of macromolecules across vascular endothelium and its modification by fluid mechanical forces are important for normal tissue function and in the development of atherosclerosis. However, the routes by which macromolecules cross endothelium, the hemodynamic stresses that maintain endothelial physiology or trigger disease, and the dependence of transendothelial transport on hemodynamic stresses are controversial. We visualized pathways for macromolecule transport and determined the effect on these pathways of different types of flow. Endothelial monolayers were cultured under static conditions or on an orbital shaker producing different flow profiles in different parts of the wells. Fluorescent tracers that bound to the substrate after crossing the endothelium were used to identify transport pathways. Maps of tracer distribution were compared with numerical simulations of flow to determine effects of different shear stress metrics on permeability. Albumin-sized tracers dominantly crossed the cultured endothelium via junctions between neighboring cells, high-density lipoprotein-sized tracers crossed at tricellular junctions, and low-density lipoprotein-sized tracers crossed through cells. Cells aligned close to the angle that minimized shear stresses across their long axis. The rate of paracellular transport under flow correlated with the magnitude of these minimized transverse stresses, whereas transport across cells was uniformly reduced by all types of flow. These results contradict the long-standing two-pore theory of solute transport across microvessel walls and the consensus view that endothelial cells align with the mean shear vector. They suggest that endothelial cells minimize transverse shear, supporting its postulated proatherogenic role. Preliminary data show that similar tracer techniques are practicable in vivo.NEW & NOTEWORTHY Solutes of increasing size crossed cultured endothelium through intercellular junctions, through tricellular junctions, or transcellularly. Cells aligned to minimize the shear stress acting across their long axis. Paracellular transport correlated with the level of this minimized shear, but transcellular transport was reduced uniformly by flow regardless of the shear profile.

Prevalence and outcomes of extrahepatic primary malignancy associated with hepatocellular carcinoma in a Korean population.

BACKGROUND: With advances in hepatocellular carcinoma (HCC) screening and treatment, the incidence of diagnosing a case of extrahepatic primary malignancy (EHPM) in patients with HCC has increased. This study aimed to elucidate the prevalence and clinical outcomes of EHPM in patients with HCC who underwent curative resection in Korea. METHODS: The clinical data of 250 patients with HCC who underwent curative resection in our hospital from May 2003 to December 2011 were retrospectively analyzed. The clinical features, overall survival, and causes of death were compared between patients with HCC with or without EHPM. RESULTS: The prevalence of EHPM among the 250 patients was 13.2% (n = 33). The most common site of EHPM was the colorectal (n = 10), followed by the stomach (n = 9), breasts (n = 4), and kidneys (n = 3). Patients with EHPM were significantly older, and they presented with higher rates of comorbidities, a different etiology of HCC, and better liver function than patients without EHPM. Interestingly, overall survival was significantly lower in the EHPM group, which more frequently displayed extrahepatic causes of death. Moreover, the presence of EHPM was an independent factor for overall survival in the study population. CONCLUSIONS: The prevalence of EHPM in patients with HCC who underwent curative surgical resection was 13.2% in Korea, with colorectal and stomach cancers comprising most EHPMs (88%). The patients with EHPM displayed significantly worse survival because of extrahepatic causes of death, which should be considered in the management of HCC in the future.

Prediction of risk for hepatocellular carcinoma by response of serum α-fetoprotein to entecavir therapy.

BACKGROUND AND AIMS: Serum α-fetoprotein (AFP) is frequently elevated in patients with chronic hepatitis B (CHB) who do not have hepatocellular carcinoma (HCC). Entecavir (ETV) treatment reduces AFP levels in these patients, but the clinical significance of AFP response to ETV has not been fully studied. The aims of this study were to elucidate the temporal response of AFP to ETV therapy and to determine the relationship between AFP response and the subsequent development of HCC. METHODS: All consecutive nucleos(t)ide-naïve CHB patients who started ETV therapy between March 2007 and February 2009 were selected from an electronic medical record database at a tertiary referral center (BESTCare). Clinical, biochemical, and virologic parameters were evaluated in relation to the serial AFP levels tested during ETV treatment. RESULTS: Among the 244 enrolled patients, 66 had elevated AFP levels before ETV therapy. Low serum albumin was a significant predictor for elevated AFP. During 12 months of ETV therapy, AFP levels normalized in approximately three fourths of these patients. The decrease in AFP was delayed in patients with high baseline hepatitis B virus titers and in patients who subsequently developed HCC during ETV therapy. Incidence of HCC was similar regardless of baseline AFP levels. Among patients with elevated AFP, however, HCC developed exclusively in the subgroup where elevated AFP persisted for more than 6 months of ETV therapy. CONCLUSIONS: Delayed AFP response to ETV may serve as an indicator of high HCC risk.

Treatment outcomes of transcatheter arterial chemoembolization for hepatocellular carcinoma that invades hepatic vein or inferior vena cava.

PURPOSE: We aimed to elucidate the treatment outcomes of transcatheter arterial chemoembolization (TACE) and survival-associated factors in hepatocellular carcinoma (HCC) patients with hepatic vein (HV) and/or inferior vena cava (IVC) invasion. METHODS: The subjects were consecutively enrolled, newly diagnosed HCC patients with HV/IVC invasion who underwent TACE (n = 62) at the Seoul National University Bundang Hospital from May 2003 to October 2012. Clinical characteristics, treatment responses, overall survival, and survival-related factors were analyzed. RESULTS: The mean subject age was 56.6 years, 82.3% were hepatitis B surface antigen-positive, and 76.2% were classified as Child-Pugh class A. The tumor volume was ≥50% of the liver in 64.5% of patients, and 79, 41.9, and 9.7% of patients had accompanying portal vein, IVC, and right atrial invasion, respectively. TACE response rates for primary tumors and tumor thrombi in HV or IVC were 55.6 and 13%, respectively. Median overall survival was 10.9 months (range 0.1-23.0 months). Multivariate analysis showed that Child-Pugh class A (hazard ratio [HR] = 0.31; 95% confidence interval [CI] 0.14-0.72; p = 0.007), tumor volume <50% of liver (HR = 0.31; 95% CI 0.11-0.83; p = 0.019), alpha-fetoprotein (AFP) response (HR = 0.28; 95% CI 0.11-0.69; p = 0.006), and tumor thrombi treatment response (HR = 0.09; 95% CI 0.01-0.77; p = 0.027) were independent survival-related factors. CONCLUSIONS: TACE seems effective for HCC with HV/IVC invasion, especially in patients with preserved hepatic function, a treatment response for tumor thrombi, and an AFP response.

Bilateral Necrotizing Fasciitis around the Hips Differentiated from Fournier Gangrene: A Case Report.

As an emergency encountered in orthopedic practice requiring prompt diagnosis and aggressive treatment, necrotizing fasciitis around the hip must be discriminated from Fournier gangrene. The current case report describes a patient who suffered from bilateral type I necrotizing fasciitis around the hips, which was alleviated by prompt surgical debridement and intensive postoperative care.