Spatial Systems Lipidomics Reveals Nonalcoholic Fatty Liver Disease Heterogeneity.

Hepatocellular lipid accumulation characterizes nonalcoholic fatty liver disease (NAFLD). However, the types of lipids associated with disease progression are debated, as is the impact of their localization. Traditional lipidomics analysis using liver homogenates or plasma dilutes and averages lipid concentrations, and does not provide spatial information about lipid distribution. We aimed to characterize the distribution of specific lipid species related to NAFLD severity by performing label-free molecular analysis by mass spectrometry imaging (MSI). Fresh frozen liver biopsies from obese subjects undergoing bariatric surgery ( n = 23) with various degrees of NAFLD were cryosectioned and analyzed by matrix-assisted laser desorption/ionization (MALDI)-MSI. Molecular identification was verified by tandem MS. Tissue sections were histopathologically stained, annotated according to the Kleiner classification, and coregistered with the MSI data set. Lipid pathway analysis was performed and linked to local proteome networks. Spatially resolved lipid profiles showed pronounced differences between nonsteatotic and steatotic tissues. Lipid identification and network analyses revealed phosphatidylinositols and arachidonic acid metabolism in nonsteatotic regions, whereas low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) metabolism was associated with steatotic tissue. Supervised and unsupervised discriminant analysis using lipid based classifiers outperformed simulated analysis of liver tissue homogenates in predicting steatosis severity. We conclude that lipid composition of steatotic and nonsteatotic tissue is highly distinct, implying that spatial context is important for understanding the mechanisms of lipid accumulation in NAFLD. MSI combined with principal component-linear discriminant analysis linking lipid and protein pathways represents a novel tool enabling detailed, comprehensive studies of the heterogeneity of NAFLD.

Decreased nucleotide excision repair in steatotic livers associates with myeloperoxidase-immunoreactivity.

Chronic inflammation is characterized by the influx of neutrophils and is associated with an increased production of reactive oxygen species that can damage DNA. Oxidative DNA damage is generally thought to be involved in the increased risk of cancer in inflamed tissues. We previously demonstrated that activated neutrophil mediated oxidative stress results in a reduction in nucleotide excision repair (NER) capacity, which could further enhance mutagenesis. Inflammation and oxidative stress are critical factors in the progression of nonalcoholic fatty liver disease that is linked with enhanced liver cancer risk. In this report, we therefore evaluated the role of neutrophils and the associated oxidative stress in damage recognition and DNA repair in steatotic livers of 35 severely obese subjects with either nonalcoholic steatohepatitis (NASH) (n=17) or steatosis alone (n=18). The neutrophilic influx in liver was assessed by myeloperoxidase (MPO) staining and the amount of oxidative DNA damage by measuring M(1)dG adducts. No differences in M(1)dG adduct levels were observed between patients with or without NASH and also not between individuals with high or low MPO immunoreactivity. However, we found that high expression of MPO in the liver, irrespective of disease status, reduced the damage recognition capacity as determined by staining for histone 2AX phosphorylation (γH2AX). This reduction in γH2AX formation in individuals with high MPO immunoreactivity was paralleled by a significant decrease in NER capacity as assessed by a functional repair assay, and was not related to cell proliferation. Thus, the observed reduction in NER capacity upon hepatic inflammation is associated with and may be a consequence of reduced damage recognition. These findings suggest a novel mechanism of liver cancer development in patients with nonalcoholic fatty liver disease.

Pregnant Women After Bariatric Surgery: Diagnostic Accuracy of Magnetic Resonance Imaging for Small Bowel Obstruction.

BACKGROUND: Small bowel obstruction (SBO) is a late complication of Roux-en-Y gastric bypass (RYGB). In non-pregnant patients, computed tomography (CT) is the first choice of imaging. During pregnancy, magnetic resonance imaging (MRI) is preferred to limit exposure to ionizing radiation. However, literature regarding the diagnostic accuracy of MRI for SBO is scarce. OBJECTIVE: To describe the diagnostic accuracy of MRI for SBO during pregnancy. METHODS: Pregnant women with RYGB suspected for SBO who presented at our center between September 2015 and April 2020 and who received an MRI scan (index) and underwent surgery (reference) were included. Original reports were retrospectively evaluated. Available MRI scans were structurally reinterpreted by two experienced radiologists. Statistical analysis included sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and Cohen's kappa. RESULTS: Twenty-seven original MRI reports were included. Twenty-four (89%) MRIs were of good quality. Sensitivity was 67% (confidence interval (CI) 0.43-0.85), specificity 67% (CI 0.13-0.98), PPV 93% (CI 0.66-0.99), and NPV 22% (CI 0.04-0.60). MRI was unable to detect SBO in 1 out of 3 patients. The presence of swirl sign, SBO sign, or clustered loop sign increases the likelihood of SBO. The interobserver agreement was overall wide, with the highest score for swirl sign (κ 0.762). DISCUSSION: MRI is a safe and feasible alternative for CT. The value is doubtful as diagnostic accuracy shows wide ranges with considerable variability in the interobserver agreement. We would cautiously advise to perform MRI in case of a mild clinical presentation, but in case of a severe clinic, the diagnostic laparoscopy should remain the gold standard.

SGA and measures for muscle mass and strength in surgical Vietnamese patients.

OBJECTIVE: This study compared the outcome of the Subjective Global Assessment (SGA) in preoperative surgical patients with objective measurements of muscle mass and strength and with biochemical data. A secondary aim was to test the influence of inflammatory activity on muscle strength. METHODS: Two hundred seventy-four consecutive patients who were admitted for elective major abdominal surgery were assessed using the SGA, anthropometry, muscle strength, and laboratory measurements (hemoglobin, protein, albumin, C-reactive protein, and lymphocytes). Normal values for midarm muscle circumference (MAMC) and handgrip strength were obtained in a healthy control group. For all other variables, normal values available for the Vietnamese population were used. RESULTS: Of 274 patients (151 men, 123 women) assessed, 61 (22.3%) were classified as SGA class A (well nourished), 97 patients (35.4%) as class B (moderately malnourished), and 116 patients (42.3%) as class C (severely malnourished). There were significant differences in age, body weight, percentage of weight loss, triceps skinfold thickness, MAMC, and serum albumin across the three SGA classes. Almost all patients rated class A had normal MAMC and handgrip strength. However, a large proportion of patients rated as B or C also had normal MAMC and handgrip strength (38% of men, 50% of women). Handgrip strength per square meter correlated with serum albumin (r = 0.278, P < 0.001) and this correlation persisted when handgrip strength was controlled for MAMC (r = 0.296, P < 0.001 in men; r = 0.237, P < 0.01 in women). CONCLUSION: The SGA correctly identifies patients with normal muscle mass and strength but a substantial number of patients rated SGA B or C have normal muscle mass and strength. Muscle strength is not only positively associated with muscle mass but also negatively with inflammatory activity.

One-year cost-effectiveness of surgical treatment of morbid obesity: vertical banded gastroplasty versus Lap-Band.

BACKGROUND: This study was designed as an economic evaluation alongside a randomized clinical trial. The object of this study was to evaluate the 1-year cost-effectiveness of surgical treatment of morbid obesity comparing two operations. METHODS: 100 patients were assigned randomly to vertical banded gastroplasty (VBG) or Lap-Band surgery. Both medical and non-medical costs were identified and measured. Costs data were combined with percentage Excess Weight Loss (%EWL) and with Quality Adjusted Life Years (QALYs) to obtain cost per %EWL and cost per QALY ratios. RESULTS: At 1 year, the total costs were not significantly different between both groups (95% confidence interval E5,999-E1,765). Also, the QALY gain after surgery was not significantly different between the two groups. However, %EWL was significantly higher in the VBG group compared to the Lap-Band group, P-value .0001. The estimated incremental cost per %EWL was E105.83 (E1,885.91/-17.82). For the costs per QALY, the estimated ratio was dominant. The overall mortality in this study was 2%. 2 patients in the VBG group died within 30 days after surgery; 1 of these deaths was possibly related to the VBG procedure. CONCLUSION: At 1 year after surgery, the costs and QoL of the two treatment modalities were found to be equal. Therefore, the selection of the procedure can be based on the clinical aspects, effectivity and safety at 1 year. In addition, the results of a long-term cost-effectiveness analysis (e.g. with a follow-up of 36 months) planned in the future can also be helpful in the selection of the preferred treatment.

Early stress protein gene expression in a human model of ischemic preconditioning.

Intermittent clamping of the porta hepatis (PHC) is commonly performed during liver surgery to reduce blood loss and has been reported to precondition livers resulting in improved outcome after liver surgery (humans) and transplantation (animals). This study investigated the early expression of cytoprotective stress proteins during ischemia-reperfusion induced by PHC. Liver samples were taken before and after each event in a two-cycle ischemia-reperfusion protocol using 15 minutes of PHC followed by 5 minutes of reperfusion. Liver tissue was analyzed by real-time polymerase chain reaction for heme oxygenase (HO)-1 and heat shock protein (HSP)-70 mRNA expression. Extracted protein was analyzed by Western blot for HO-1, and HSP-70 and nuclear extracts were analyzed by DNA mobility shift assay for hypoxia inducible factor (HIF)-1alpha and heat shock factor (HSF)-1. Within minutes of PHC, significant increases in HO-1 mRNA expression were detected, and these were maintained throughout the protocol (P < 0.01). Protein expression of HO-1 (P < 0.03) and HO-1 activity (P < 0.05) were similarly increased between the start and end of ischemia- reperfusion (40 minutes). Binding of active HIF-1alpha to its consensus sequence was increased within 15 minutes of the start of the ischemia-reperfusion cycle. Although evidence of the transcriptionally active form of HSF-1 was detected at the same time point, this was not reflected in measurable changes in HSP-70 mRNA or protein. In conclusion, expression of the cytoprotective protein HO-1 is significantly up-regulated in the liver within minutes of PHC. It is likely that HO-1 contributes to the early protective effects of ischemic preconditioning.

Clinical follow-up of horses treated with allogeneic equine mesenchymal stem cells derived from umbilical cord blood for different tendon and ligament disorders.

BACKGROUND: Mesenchymal stem cells (MSCs) offer promise as therapeutic aids in the repair of tendon and ligament disorders in sport horses. Equine allogeneic MSCs derived from umbilical cord blood (eUCB-MSCs) can be obtained in a minimally invasive fashion with successful propagation of MSCs. OBJECTIVE: The objective of this study was to determine the applicability and therapeutic effect of eUCB-MSCs on tendinitis of the superficial digital flexor tendon, desmitis of the suspensory ligament, tendinitis of the deep digital flexor tendon, and desmitis of the inferior check ligament in clinical cases. METHODS: A retrospective clinical study was performed. At two equine clinics, 52 warmblood horses were treated with cultured eUCB-MSCs between 2009 and 2012. About 2-10 × 10(6) cells per lesion were administered. When a lesion was treated twice, the total amount could run up to 20 × 10(6) cells. Pearson's chi-squared test was used to compare the effect of the injured structure on the success rate, as well as the effect of the age of the horse. RESULTS: Based on repeated examinations, 40 horses (77%) returned to work on the same or a higher level based on information provided by the owner. Neither the injured structure nor the age of the horse had a statistically significant influence on the result. CONCLUSION: Overall, the results of treatment of some tendon and ligament injuries with eUCB-MSCs in clinical cases are promising.

Lack of evidence for the role of human adenovirus-36 in obesity in a European cohort.

Adenovirus infection has been shown to increase adiposity in chickens, mice, and nonhuman primates. Adenovirus type 36 (Ad-36) DNA was detected in adipose tissues in these animal trials. In the United States, Ad-36 significantly correlates with obesity as illustrated by an Ad-36 seroprevalence of 30% in obese individuals and 11% in nonobese individuals. We investigated the possibility of a similar correlation of Ad-36 in Dutch and Belgian persons. In total, 509 serum samples were analyzed for Ad-36 antibodies using a serum neutralization assay. In addition, PCR was used to detect adenoviral DNA in visceral adipose tissue of 31 severely obese surgical patients. Our results indicated an overall Ad-36 seroprevalence of 5.5% increasing with age. BMI of Ad-36 seropositive humans was not significantly different from seronegative humans. No adenoviral DNA could be found using PCR on visceral adipose tissue. In conclusion, this first Ad-36 study in the Netherlands and in Belgium indicates that Ad-36 does not play a role as a direct cause of BMI increase and obesity in humans in Western Europe.