Non-contrast based approach for liver function quantification using Bayesian-based intravoxel incoherent motion diffusion weighted imaging: A pilot study.

PURPOSE: Liver cirrhosis disrupts liver function and tissue perfusion, detectable by magnetic resonance imaging (MRI). Assessing liver function at the voxel level with 13-b value intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) could aid in radiation therapy liver-sparing treatment for patients with early impairment. This study aimed to evaluate the feasibility of IVIM-DWI for liver function assessment and correlate it with other multiparametric (mp) MRI methods at the voxel level. METHOD: This study investigates the variability of apparent diffusion coefficient (ADC) derived from 13-b value IVIM-DWI and B1-corrected dual flip angle (DFA) T1 mapping. Experiments were conducted in-vitro with QIBA and NIST phantoms and in 10 healthy volunteers for IVIM-DWI. Additionally, 12 patients underwent an mp-MRI examination. The imaging protocol included a 13-b value IVIM-DWI sequence for generating IVIM parametric maps. B1-corrected DFA T1 pulse sequence was used for generating T1 maps, and Gadoxatate low temporal resolution dynamic contrast-enhanced (LTR-DCE) MRI was used for generating the Hepatic extraction fraction (HEF) map. The Mann-Whitney U test was employed to compare IVIM-DWI parameters (Pure Diffusion, Dslow ; Pseudo diffusion, Dfast ; and Perfusion Fraction, Fp ) between the healthy volunteer and patient groups. Furthermore, in the patient group, statistical correlations were assessed at a voxel level between LTR-DCE MRI-derived HEF, T1 post-Gadoxetate administration, ΔT1%, and various IVIM parameters using Pearson correlation. RESULTS: For-vitro measurements, the maximum coefficient of variation of the ADC and T1 parameters was 12.4% and 16.1%, respectively. The results also showed that Fp and Dfast were able to distinguish between healthy liver function and mild liver function impairment at the global level, with p = 0.002 for Fp and p < 0.001 for Dfast . Within the patient group, these parameters also exhibited a moderate correlation with HEF at the voxel level. CONCLUSION: Overall, the study highlighted the potential of Dfast and Fp for detecting liver function impairment at both global and pixel levels.

Defects in NLRP6, autophagy and goblet cell homeostasis are associated with reduced duodenal CRH receptor 2 expression in patients with functional dyspepsia.

Functional dyspepsia (FD) affects up to 15% of the population and is characterised by recurring upper gastrointestinal (GI) symptoms occurring in the absence of clinically identifiable pathology. Psychological stress is a key factor associated with the onset of FD and locally acting hypothalamic-pituitary-adrenal (HPA) axis hormones have been implicated in GI motility and barrier dysfunction. Recent pre-clinical work has identified mechanistic pathways linking corticotropin-releasing hormone (CRH) with the innate epithelial immune protein NLRP6, an inflammasome that has been shown to regulate GI mucus secretion. We recruited twelve FD patients and twelve healthy individuals to examine whether dysregulation of hypothalamic-pituitary adrenal (HPA) axis hormones and altered NLRP6 pathways were evident in the duodenal mucosa. Protein expression was assessed by immunoblot and immunohistochemistry in D2 duodenal biopsies. Plasma HPA axis hormones were assayed by ELISA and enteroid and colorectal cancer cell line cultures were used to verify function. FD patients exhibited reduced duodenal CRH-receptor 2, compared to non-GI disease controls, indicating a dysregulation of duodenal HPA signalling. The loss of CRH-receptor 2 correlated with reduced NLRP6 expression and autophagy function, processes critical for maintaining goblet cell homeostasis. In accordance, duodenal goblet cell numbers and mucin exocytosis was reduced in FD patients compared to controls. In vitro studies demonstrated that CRH could reduce NLRP6 in duodenal spheroids and promote mucus secretion in the HT29-MTX-E12 cell line. In conclusion, FD patients exhibit defects in the NLRP6-autophagy axis with decreased goblet cell function that may drive symptoms of disease. These features correlated with loss of CRH receptor 2 and may be driven by dysregulation of HPA signalling in the duodenum of FD patients.

Hepatocyte free cholesterol lipotoxicity results from JNK1-mediated mitochondrial injury and is HMGB1 and TLR4-dependent.

BACKGROUND & AIMS: Free cholesterol (FC) accumulates in non-alcoholic steatohepatitis (NASH) but not in simple steatosis. We sought to establish how FC causes hepatocyte injury. METHODS: In NASH-affected livers from diabetic mice, subcellular FC distribution (filipin fluorescence) was established by subcellular marker co-localization. We loaded murine hepatocytes with FC by incubation with low-density lipoprotein (LDL) and studied the effects of FC on JNK1 activation, mitochondrial injury and cell death and on the amplifying roles of the high-mobility-group-box 1 (HMGB1) protein and the Toll-like receptor 4 (TLR4). RESULTS: In NASH, FC localized to hepatocyte plasma membrane, mitochondria and ER. This was reproduced in FC-loaded hepatocytes. At 40 µM LDL, hepatocyte FC increased to cause LDH leakage, apoptosis and necrosis associated with JNK1 activation (c-Jun phosphorylation), mitochondrial membrane pore transition, cytochrome c release, oxidative stress (GSSG:GSH ratio) and ATP depletion. Mitochondrial swelling and crystae disarray were evident by electron microscopy. Jnk1(-/-) and Tlr4(-/-) hepatocytes were refractory to FC lipotoxicity; JNK inhibitors (1-2 µM CC-401, CC-930) blocked apoptosis and necrosis. Cyclosporine A and caspase-3 inhibitors protected FC-loaded hepatocytes, confirming mitochondrial cell death pathways; in contrast, 4-phenylbutyric acid, which improves ER folding capacity did not protect FC-loaded hepatocytes. HMGB1 was released into the culture medium of FC-loaded wild type (WT) but not Jnk1(-/-) or Tlr4(-/-) hepatocytes, while anti-HMGB1 anti-serum prevented JNK activation and FC lipotoxicity in WT hepatocytes. CONCLUSIONS: These novel findings show that mitochondrial FC deposition causes hepatocyte apoptosis and necrosis by activating JNK1; inhibition of which could be a novel therapeutic approach in NASH. Further, there is a tight link between JNK1-dependent HMGB1 secretion from lipotoxic hepatocytes and a paracrine cytolytic effect on neighbouring cholesterol-loaded hepatocytes operating via TLR4.

Pharmacological cholesterol lowering reverses fibrotic NASH in obese, diabetic mice with metabolic syndrome.

BACKGROUND & AIMS: We have recently showed that hyperinsulinemia promotes hepatic free cholesterol (FC) accumulation in obese, insulin-resistant Alms1 mutant (foz/foz) mice with NASH. Here we tested whether cholesterol-lowering drugs reduce stress-activated c-Jun N-terminal kinase (JNK) activation, hepatocyte injury/apoptosis, inflammation, and fibrosis in this metabolic syndrome NASH model. METHODS: Female foz/foz and WT mice were fed HF (0.2% cholesterol) 16 weeks, before adding ezetimibe (5 mg/kg), atorvastatin (20 mg/kg), or both to diet, another 8 weeks. Hepatic lipidomic analysis, ALT, liver histology, Sirius Red morphometry, hepatic mRNA and protein expression and immunohistochemistry (IHC) for apoptosis (M30), macrophages (F4/80), and polymorphs (myeloperoxidase) were determined. RESULTS: In mice with NASH, ezetimibe/atorvastatin combination normalized hepatic FC but did not alter saturated free fatty acids (FFA) and had minimal effects on other lipids; ezetimibe and atorvastatin had similar but less profound effects. Pharmacological lowering of FC abolished JNK activation, improved serum ALT, apoptosis, liver inflammation/NAFLD activity score, designation as "NASH", macrophage chemotactic protein-1 expression, reduced macrophage and polymorph populations, and liver fibrosis. CONCLUSIONS: Cholesterol lowering with ezetimibe/atorvastatin combination reverses hepatic FC but not saturated FFA accumulation. This dampens JNK activation, ALT release, hepatocyte apoptosis, and inflammatory recruitment, with reversal of steatohepatitis pathology and liver fibrosis. Ezetimibe/statin combination is a potent, mechanism-based treatment that could reverse NASH and liver fibrosis.

Acute respiratory failure induced by belly dancer's syndrome: A glance to a rare case report.

Respiratory myoclonus, also known as belly dancer's dyskinesia (BDD), is a rare manifestation of movement disorder characterized by repetitive choreiform involuntary movements involving the anterior abdominal muscles, the diaphragm, and other respiratory muscles. Currently, there is no definite pathophysiology that clearly explains this condition. A 25-year-old male with a known case of BDD presented with an exacerbation of involuntary and continuous writhing movements of the abdominal wall muscles associated with abdominal pain and shortness of breath over the past 2 days. Subsequently, he was intubated due to worsening respiratory distress a few days after his admission. He was then put on ultrasound-guided botulinum toxin A injections of 25 units over the left hemidiaphragm regularly. His symptoms markedly improved since then as the attacks had reduced to 5-6 monthly intervals. Administration of ultrasound-guided botulinum toxin A injections may help to control the exacerbation of BDD and might be an option for cases refractory to medical treatment and phrenic nerve ablation.

TRAV26-2 T-Cell Receptor Expression Is Associated With Mucosal Lymphocyte Response to Wheat Proteins in Patients With Functional Dyspepsia.

INTRODUCTION: An association between functional dyspepsia (FD) and wheat-containing foods has been reported in observational studies; however, an adaptive response has not been demonstrated. We examined whether antigens present in wheat could provoke a response from FD duodenal lymphocytes. METHODS: Lamina propria mononuclear cells (LPMCs) were isolated from duodenal biopsies from 50 patients with FD and 23 controls. LPMCs were exposed to gluten (0.2 mg/mL) or gliadin (0.2 mg/mL) for 24 hours. Flow cytometry was performed to phenotype lymphocytes. Quantitative PCR was used to measure the expression of gliadin-associated T-cell receptor alpha variant ( TRAV ) 26-2. RESULTS: In response to gliadin (but not gluten) stimulation, the effector Th2-like population was increased in FD LPMCs compared with that in controls and unstimulated FD LPMCs. Duodenal gene expression of TRAV26- 2 was decreased in patients with FD compared with that in controls. We identified a positive association between gene expression of this T-cell receptor variant and LPMC effector Th17-like cell populations in patients with FD, but not controls after exposure to gluten, but not gliadin. DISCUSSION: Our findings suggest that gliadin exposure provokes a duodenal effector Th2-like response in patients with FD, supporting the notion that food antigens drive responses in some patients. Furthermore, these findings suggest that altered lymphocyte responses to wheat proteins play a role in FD pathogenesis.

Type 2 and type 17 effector cells are increased in the duodenal mucosa but not peripheral blood of patients with functional dyspepsia.

Background: Functional dyspepsia is characterised by chronic symptoms of post-prandial distress or epigastric pain not associated with defined structural pathology. Increased peripheral gut-homing T cells have been previously identified in patients. To date, it is unknown if these T cells were antigen-experienced, or if a specific phenotype was associated with FD. Objective: This study aimed to characterise T cell populations in the blood and duodenal mucosa of FD patients that may be implicated in disease pathophysiology. Methods: We identified duodenal T cell populations from 23 controls and 49 Rome III FD patients by flow cytometry using a surface marker antibody panel. We also analysed T cell populations in peripheral blood from 37 controls and 61 patients. Where available, we examined the number of duodenal eosinophils in patients and controls. Results: There was a shift in the duodenal T helper cell balance in FD patients compared to controls. For example, patients had increased duodenal mucosal Th2 populations in the effector (13.03 ± 16.11, 19.84 ± 15.51, p=0.038), central memory (23.75 ± 18.97, 37.52 ± 17.51, p=0.007) and effector memory (9.80±10.50 vs 20.53±14.15, p=0.001) populations. Th17 populations were also increased in the effector (31.74±24.73 vs 45.57±23.75, p=0.03) and effector memory (11.95±8.42 vs 18.44±15.63, p=0.027) subsets. Peripheral T cell populations were unchanged between FD and control. Conclusion: Our findings identify an association between lymphocyte populations and FD, specifically a Th2 and Th17 signature in the duodenal mucosa. The presence of effector and memory cells suggest that the microinflammation in FD is antigen driven.

Plethora of Antibiotics Usage and Evaluation of Carbapenem Prescribing Pattern in Intensive Care Units: A Single-Center Experience of Malaysian Academic Hospital.

Excessive antibiotic consumption is still common among critically ill patients admitted to intensive care units (ICU), especially during the coronavirus disease 2019 (COVID-19) period. Moreover, information regarding antimicrobial consumption among ICUs in South-East Asia remains scarce and limited. This study aims to determine antibiotics utilization in ICUs by measuring antibiotics consumption over the past six years (2016−2021) and specifically evaluating carbapenems prescribed in a COVID-19 ICU and a general intensive care unit (GICU) during the second year of the COVID-19 pandemic. (2) Methods: This is a retrospective cross-sectional observational analysis of antibiotics consumption and carbapenems prescriptions. Antibiotic utilization data were estimated using the WHO Defined Daily Doses (DDD). Carbapenems prescription information was extracted from the audits conducted by ward pharmacists. Patients who were prescribed carbapenems during their admission to COVID-19 ICU and GICU were included. Patients who passed away before being reviewed by the pharmacists were excluded. (3) Results: In general, antibiotics consumption increased markedly in the year 2021 when compared to previous years. Majority of carbapenems were prescribed empirically (86.8%). Comparing COVID-19 ICU and GICU, the reasons for empirical carbapenems therapy in COVID-19 ICU was predominantly for therapy escalation (64.7% COVID-19 ICU vs. 34% GICU, p < 0.001), whereas empirical prescription in GICU was for coverage of extended-spectrum beta-lactamases (ESBL) gram-negative bacteria (GNB) (45.3% GICU vs. 22.4% COVID-19 ICU, p = 0.005). Despite microbiological evidence, the empirical carbapenems were continued for a median (interquartile range (IQR)) of seven (5−8) days. This implies the need for a rapid diagnostic assay on direct specimens, together with comprehensive antimicrobial stewardship (AMS) discourse with intensivists to address this issue.

NASH is an Inflammatory Disorder: Pathogenic, Prognostic and Therapeutic Implications.

While non-alcoholic fatty liver disease (NAFLD) is highly prevalent (15% to 45%) in modern societies, only 10% to 25% of cases develop hepatic fibrosis leading to cirrhosis, end-stage liver disease or hepatocellular carcinoma. Apart from pre-existing fibrosis, the strongest predictor of fibrotic progression in NAFLD is steatohepatitis or non-alcoholic steatohepatitis (NASH). The critical features other than steatosis are hepatocellular degeneration (ballooning, Mallory hyaline) and mixed inflammatory cell infiltration. While much is understood about the relationship of steatosis to metabolic factors (over-nutrition, insulin resistance, hyperglycemia, metabolic syndrome, hypoadiponectinemia), less is known about inflammatory recruitment, despite its importance for the perpetuation of liver injury and fibrogenesis. In this review, we present evidence that liver inflammation has prognostic significance in NAFLD. We then consider the origins and components of liver inflammation in NASH. Hepatocytes injured by toxic lipid molecules (lipotoxicity) play a central role in the recruitment of innate immunity involving Toll-like receptors (TLRs), Kupffer cells (KCs), lymphocytes and neutrophils and possibly inflammasome. The key pro-inflammatory signaling pathways in NASH are nuclear factor-kappa B (NF-κB) and c-Jun N-terminal kinase (JNK). The downstream effectors include adhesion molecules, chemokines, cytokines and the activation of cell death pathways leading to apoptosis. The upstream activators of NF-κB and JNK are more contentious and may depend on the experimental model used. TLRs are strong contenders. It remains possible that inflammation in NASH originates outside the liver and in the gut microbiota that prime KC/TLR responses, inflamed adipose tissue and circulating inflammatory cells. We briefly review these mechanistic considerations and project their implications for the effective treatment of NASH.

Mechanisms and implications of age-related changes in the liver: nonalcoholic Fatty liver disease in the elderly.

Nonalcoholic fatty liver disease (NAFLD) is hepatic steatosis associated with metabolic abnormalities such as overweight/central obesity, insulin resistance, type 2 diabetes (T2D), and dyslipidemia. NAFLD is becoming the most common liver disease in contemporary society, with the highest prevalence in those over 60 years. NAFLD pathology ranges from simple steatosis to a necroinflammatory fibrosing disorder called steatohepatitis (SH), the latter associated with high risk of developing cirrhosis, often occuring in the seventh to ninth decades of life. While the main health implications of NAFLD are increased risk of developing T2D, cardiovascular diseases, and common cancers, there is substantantially increased standardized mortality, and deaths from decompensated cirrhosis and hepatocellular carcinoma (HCC). Little is known about the interactive effects of ageing and NAFLD, with most studies focusing on the younger population. This paper summarises the epidemiology, pathogenesis, and clinical course of NAFLD, with particular attention to persons over age 60 years. An approach to the management of NASH and its complications in the elderly, will also be presented here.