A Same-Genus Screening Approach Reveals Novel Effectors and New Possibilities for Investigating Chlamydia Pathogenesis.

Chlamydiae are obligate intracellular pathogens that rely on secreted effector proteins to establish their intracellular niche. In this issue of the Journal of Bacteriology, Yanatori et al describe a screen for C. pneumoniae effectors, performed in C. trachomatis, which identified several new proteins that are translocated during infection (Yanatori, Miura et al. 2021). More broadly, they demonstrate how new genetic approaches in C. trachomatis can be used to characterize the virulence factors of other Chlamydia species.

No Pathogen-Specific Sign or Symptom Predicts the Etiology of Monomicrobial Nongonococcal Urethritis in Men.

Identifying pathogen-specific signs or symptoms of nongonococcal urethritis could improve syndromic management accuracy. We evaluated nongonococcal urethritis signs and symptoms in 220 men with single-pathogen infections (Chlamydia trachomatis, Mycoplasma genitalium, Trichomonas vaginalis, or Ureaplasma urealyticum) or idiopathic urethritis. No individual sign or symptom accurately predicted the infectious etiology.

Hepatic iron is the major determinant of serum ferritin in NAFLD patients.

BACKGROUND AND AIMS: Elevated serum ferritin is common in NAFLD, and is associated with more advanced disease and increased mortality. Hyperferritinaemia in NAFLD is often attributed to inflammation, while in other conditions ferritin closely reflects body iron stores. The aim of this study was to clarify the underlying cause of hyperferritinaemia in NAFLD. METHODS: Ferritin levels were examined with markers of iron status, inflammation and liver injury across the clinical spectrum of NAFLD using blood, tissue and magnetic resonance (MR) imaging. A separate larger group of NAFLD patients with hepatic iron staining and quantification were used for validation. RESULTS: Serum ferritin correlated closely with the iron regulatory hormone hepcidin, and liver iron levels determined by MR. Furthermore, ferritin levels reflected lower serum adiponectin, a marker of insulin resistance, and liver fat, but not cytokine or CRP levels. Ferritin levels differed according to fibrosis stage, increasing from early to moderate disease, and declining in cirrhosis. A similar pattern was found in the validation cohort of NAFLD patients, where ferritin levels were highest in those with macrophage iron deposition. Multivariate analysis revealed liver iron and hepcidin levels as the major determinants of serum ferritin. CONCLUSIONS: While hyperferritinaemia is associated with markers of liver injury and insulin resistance, serum hepcidin and hepatic iron are the strongest predictors of ferritin levels. These findings highlight the role of disordered iron homeostasis in the pathogenesis of NAFLD, suggesting that therapies aimed at correcting iron metabolism may be beneficial.

Suppression of a deletion mutation in the gene encoding essential PBP2b reveals a new lytic transglycosylase involved in peripheral peptidoglycan synthesis in Streptococcus pneumoniae D39.

In ellipsoid-shaped ovococcus bacteria, such as the pathogen Streptococcus pneumoniae (pneumococcus), side-wall (peripheral) peptidoglycan (PG) synthesis emanates from midcells and is catalyzed by the essential class B penicillin-binding protein PBP2b transpeptidase (TP). We report that mutations that inactivate the pneumococcal YceG-domain protein, Spd_1346 (renamed MltG), remove the requirement for PBP2b. ΔmltG mutants in unencapsulated strains accumulate inactivation mutations of class A PBP1a, which possesses TP and transglycosylase (TG) activities. The 'synthetic viable' genetic relationship between Δpbp1a and ΔmltG mutations extends to essential ΔmreCD and ΔrodZ mutations that misregulate peripheral PG synthesis. Remarkably, the single MltG(Y488D) change suppresses the requirement for PBP2b, MreCD, RodZ and RodA. Structural modeling and comparisons, catalytic-site changes and an interspecies chimera indicate that pneumococcal MltG is the functional homologue of the recently reported MltG endo-lytic transglycosylase of Escherichia coli. Depletion of pneumococcal MltG or mltG(Y488D) increases sphericity of cells, and MltG localizes with peripheral PG synthesis proteins during division. Finally, growth of Δpbp1a ΔmltG or mltG(Y488D) mutants depends on induction of expression of the WalRK TCS regulon of PG hydrolases. These results fit a model in which MltG releases anchored PG glycan strands synthesized by PBP1a for crosslinking by a PBP2b:RodA complex in peripheral PG synthesis.

Analytical-Based Methodologies for Examining the In Vitro Absorption, Distribution, Metabolism, and Elimination (ADME) of Silver Nanoparticles.

The clinical applications of silver nanoparticles (AgNPs) remain limited due to the lack of well-established methodologies for studying their nanokinetics. Hereby, the primary goal is to adapt a suite of analytical-based methodologies for examining the in vitro absorption, distribution, metabolism, and elimination of AgNPs. Vero 76 and HEK 293 cells are exposed to ≈10-nm spherical AgNPs+ and AgNPs- at relevant concentrations (0-300 µg mL-1 ) and times (4-48 h). Absorption: Inductively coupled plasma optical emission spectroscopy (ICP-OES) demonstrates that the two AgNP formulations are not bioequivalent. For example, different bioavailabilities (Cmaximum < 20.7 ± 4% and 6.82 ± 0.4%), absorption times (Tmaximum > 48 and ≈24 h), and absorption rate laws (first- and zeroth-order at 300 µg mL-1 ) are determined in Vero 76 for AgNPs+ and AgNPs- , respectively. Distribution: Raman and CytoViva hyperspectral imaging show different cellular localizations for AgNPs+ and AgNPs- . Metabolism: Cloud point extraction (CPE)-tangential flow filtration (TFF) reveal that ≤ 11% ± 4% of the administered, sublethal AgNPs release Ag+ and contribute to the observed cytotoxicity. Elimination: ICP-OES-CPE suggests that AgNPs are cleared via exocytosis.

MRE in NAFLD: Promising but Further Validation is Required.

MR elastography is a novel method for non-invasive fibrosis assessment, not yet sufficiently validated. In a recent study in 104 patients Park, Gastroenterology 2017; 152: 598-602), MRE was compared to transient elastography for the diagnosis of fibrosis is nonalcoholic fatty liver disease. The current viewpoint critically appraises this study.

Spleen stiffness can non-invasively assess resolution of portal hypertension after liver transplantation.

BACKGROUND & AIMS: Spleen stiffness can be measured by transient elastography. Recent studies have shown that spleen stiffness correlates with hepatic venous pressure gradient and can predict oesophageal varices. Elevated spleen stiffness in cirrhosis has been attributed to splenic tissue hyperplasia and fibrosis, portal hypertension and its consequent hyperdynamic circulation. The aim of this study was to investigate changes to spleen stiffness after orthotopic liver transplantation (OLT) when portal hypertension resolves. METHODS: Twenty-one patients awaiting OLT were studied prospectively, while 11 post-transplant patients were recruited as controls. Spleen and liver stiffness were measured with Fibroscan before and at 2-8 weeks after OLT. Criteria applied for spleen stiffness measurement were similar to liver stiffness (≥10 measurements; ≥60% success rate; interquartile range, IQR <30% of median). RESULTS: Spleen stiffness was significantly higher before OLT compared to post-transplant patients [75.0 (63.9-75.0) kPa vs. 28.4 (22.0-37.5) kPa; P < 0.0001]. For patients awaiting OLT, 90% (19/21) had oesophageal varices (endoscopically or radiologically). In patients who underwent liver transplantation, spleen stiffness decreased significantly from a median of 75.0 (62.0-75.0) kPa before OLT, to 41.9 (27.0-47.4) kPa at 2 weeks after transplant and 32.9 (29.1-38.0) kPa in the subsequent 4-8 weeks after OLT (P < 0.0001). As expected, liver stiffness measurements reduced from 39.3 (24.9-75.0) kPa to 8.6 (6.8-11.8) kPa in patients receiving OLT (P = 0.0004). CONCLUSIONS: Spleen stiffness can non-invasively assess changes in portal pressure after liver transplantation and decreases significantly when portal hypertension resolves.

Correlates of hepcidin and NTBI according to HFE status in patients referred to a liver centre.

BACKGROUND/AIMS: Innately low hepcidin levels lead to iron overload in HFE-associated hereditary haemochromatosis. METHODS: This study compared hepcidin and non-transferrin bound iron (NTBI) levels in untreated iron-loaded and non-iron-loaded C282Y homozygotes to levels in C282Y/H63D compound heterozygotes and individuals with other HFE genotypes associated with less risk of iron overload. RESULTS: As the genotypic risk for iron overload increased, transferrin saturation and serum NTBI levels increased while serum hepcidin levels decreased. Overweight and obese male C282Y homozygotes had significantly higher hepcidin levels than male C282Y homozygotes with a normal BMI. Pearson product-moment analysis showed that serum hepcidin levels significantly correlated with HFE status, serum ferritin, age, NTBI, transferrin saturation, gender and BMI. Subsequent multiple regression analysis showed that HFE status and serum ferritin were significant independent correlates of serum hepcidin levels. CONCLUSIONS: In summary, this study has shown that while serum ferritin and HFE status are the most important determinants of hepcidin levels, factors such age, gender, BMI, transferrin saturation and NTBI all interact closely in the matrix of homeostatic iron balance.

Younger age at diagnosis is associated with panenteric, but not more aggressive, Crohn's disease.

BACKGROUND & AIMS: Crohn's disease (CD) diagnosed in pediatric patients has been reported to have a more aggressive phenotype and course, with a greater prevalence of upper gastrointestinal involvement, than in adults. However, studies have not accounted for differences in diagnostic tests. We aimed to discern whether, in fact, CD diagnosed in childhood has a different outcome than CD diagnosed in adults. METHODS: We performed comprehensive medical chart reviews of 571 patients with CD (451 with complete data) who were followed in a single referral inflammatory bowel disease clinic in Winnipeg, Canada, from 1993-2012. For specific time intervals, we determined types and numbers of imaging studies performed and parameters of disease phenotype, including age at diagnosis according to the Montreal classification (A1 diagnosed <17 years of age, A2 diagnosed 17-40 years, and A3 diagnosed >40 years). RESULTS: Within 1 year of diagnosis, a higher proportion of A1 patients had upper gastrointestinal involvement and ileocolonic (L3) disease than A2 or A3 patients. These differences could be partly accounted for by the diagnostic tests performed during this time period. Although A1 patients underwent more extensive imaging studies, they had a lower prevalence of complicated disease, particularly compared with A3 patients. After a median follow-up period of 11.1 years, complicated disease behavior (B2 [structuring] or B3 [penetrating]) was similar among the 3 groups. Nonetheless, at the end of the study period, rates of inflammatory bowel disease-related abdominal surgery were significantly lower for A1 than A2 patients (odds ratio, 0.63; 95% confidence interval, 0.41-0.98) but not for A3 patients (odds ratio, 0.71; 95% confidence interval, 0.40-1.27). CONCLUSIONS: On the basis of a database analysis of different age groups of patients with CD, studies of disease phenotypes among different cohorts should account for different patterns of diagnostic imaging evaluation. Our data show that although children are at increased risk of panenteric disease, they are not more likely to have more complicated disease or undergo surgery than adults.

Biguanides and glucagon like peptide 1 receptor agonists in the amelioration of post liver transplant weight gain; a scoping review of the mechanism of action, safety and efficacy.

Weight gain post-liver transplant can lead to adverse patient outcomes in the post-transplant period. Pharmacotherapy and other measures can be utilised to reduce the burden and occurrence of weight gain in this population. We explored the mechanism of action, safety, and efficacy of these medications, specifically GLP-1 receptor agonists and metformin, focusing on liver transplant patients. This scoping review was conducted in line with the scoping review structure as outlined by the PRISMA guidelines. Metformin and GLP-1 receptor agonists have been observed to be safe and effective in liver transplant patients. Experimental models have found liver-centric weight loss mechanisms in this drug cohort. There is a paucity of evidence about the use of antihyperglycemics in a post-transplant population for weight loss purposes. However, some small studies have shown strong safety and efficacy data. The evidence in relation to using these medications in patients with metabolic syndrome for weight loss warrants further study in a transplant population.

Pegylated interferon-α induced hypoferremia is associated with the immediate response to treatment in hepatitis C.

UNLABELLED: Pegylated interferon-α (PEG-IFN-α) forms an integral part of the current treatment for hepatitis C virus (HCV) infection. PEG-IFN-α suppresses HCV production by augmenting the innate antiviral immune response. Recent studies have reported the induction of hepcidin, the iron regulatory hormone, by IFN-α in vitro. As hepcidin plays an important role in innate immunity, we hypothesized that this finding may be of clinical relevance to HCV and investigated the changes in iron homeostasis during the first 24 hours of treatment. Blood samples were obtained from HCV patients immediately prior to and 6, 12, and 24 hours following the first dose of PEG-IFN-α/ribavirin (RBV). Samples were analyzed for hepcidin, cytokine, iron levels, and HCV viral load, and hepcidin messenger RNA (mRNA) expression was quantified in peripheral blood mononuclear cells. Hepcidin induction by IFN-α was further analyzed in cell culture. In HCV patients a single dose of PEG-IFN-α/RBV resulted in a significant increase in serum hepcidin, peaking at 12 hours, coinciding with a 50% reduction in serum iron and transferrin saturation over the 24-hour period. Patients with a ≥ 2 log decline in HCV viral load over the first 24 hours had significantly lower SI and TS levels at 12 and 24 hours. Moreover, 24-hour SI levels were an independent predictor of the immediate HCV viral decline, an indicator of ultimate treatment outcome. In cell culture, a direct induction of hepcidin by IFN-α was seen, controlled by the STAT3 transcription factor. CONCLUSION: Hepcidin induction occurs following the initiation of PEG-IFN-α treatment for HCV, and is mediated by way of STAT3 signaling. The subsequent hypoferremia was greatest in those with the most significant decline in viral load, identifying systemic iron withdrawal as a marker of immediate interferon-α efficacy in HCV patients.

Impact of minimum unit pricing on alcohol-related hospital outcomes: systematic review.

OBJECTIVE: To determine the impact of minimum unit pricing (MUP) on the primary outcome of alcohol-related hospitalisation, and secondary outcomes of length of stay, hospital mortality and alcohol-related liver disease in hospital. DESIGN: Databases MEDLINE, Embase, Scopus, APA Psycinfo, CINAHL Plus and Cochrane Reviews were searched from 1 January 2011 to 11 November 2022. Inclusion criteria were studies evaluating the impact of minimum pricing policies, and we excluded non-minimum pricing policies or studies without alcohol-related hospital outcomes. The Effective Public Health Practice Project tool was used to assess risk of bias, and the Bradford Hill Criteria were used to infer causality for outcome measures. SETTING: MUP sets a legally required floor price per unit of alcohol and is estimated to reduce alcohol-attributable healthcare burden. PARTICIPANT: All studies meeting inclusion criteria from any country INTERVENTION: Minimum pricing policy of alcohol PRIMARY AND SECONDARY OUTCOME MEASURES: RESULTS: 22 studies met inclusion criteria; 6 natural experiments and 16 modelling studies. Countries included Australia, Canada, England, Northern Ireland, Ireland, Scotland, South Africa and Wales. Modelling studies estimated that MUP could reduce alcohol-related admissions by 3%-10% annually and the majority of real-world studies demonstrated that acute alcohol-related admissions responded immediately and reduced by 2%-9%, and chronic alcohol-related admissions lagged by 2-3 years and reduced by 4%-9% annually. Minimum pricing could target the heaviest consumers from the most deprived groups who tend to be at greatest risk of alcohol harms, and in so doing has the potential to reduce health inequalities. Using the Bradford Hill Criteria, we inferred a 'moderate-to-strong' causal link that MUP could reduce alcohol-related hospitalisation. CONCLUSIONS: Natural studies were consistent with minimum pricing modelling studies and showed that this policy could reduce alcohol-related hospitalisation and health inequalities. PROSPERO REGISTRATION NUMBER: CRD42021274023.

Tumour stemness and poor clinical outcomes in haemochromatosis patients with hepatocellular carcinoma.

AIMS: Patients with haemochromatosis (HFE) are known to have an increased risk of developing hepatocellular carcinoma (HCC). Available data are conflicting on whether such patients have poorer prognosis, and there is lack of data regarding the biology of HFE-HCC. We compared the course of HFE-HCC with a matched non-HFE-HCC control group and examined tumour characteristics using immunohistochemistry. METHODS: In this tertiary care-based retrospective analysis, 12 patients with HFE and 34 patients with alcohol/non-alcoholic steatohepatitis who underwent initially successful curative HCC therapy with ablation or resection were identified from our registry. Time to tumour progression was compared. Resected liver tissue from a separate cohort of 11 matched patients with HFE-HCC and without HFE-HCC was assessed for the expression of progenitor and epithelial-mesenchymal transition markers using immunohistochemistry. RESULTS: The median follow-up was 24.39 and 24.28 months for patients with HFE-HCC and those without HFE-HCC, respectively (p>0.05). The mean time to progression was shorter in the HFE group compared with the non-HFE group (12.87 months vs 17.78 months; HR 3.322, p<0.05). Patients with HFE-HCC also progressed to more advanced disease by the end of follow-up (p<0.05). Immunohistochemical analysis of matched HFE-HCC and non-HFE-HCC explants demonstrated increased expression of the cancer stem cell markers EpCAM (epithelial cell adhesion molecule) and EpCAM/SALL4 (spalt-like transcription factor 4) coexpression in HFE-HCC specimens (p<0.05). There was a high frequency of combined tumour subtypes within the HFE cohort. CONCLUSIONS: This study demonstrates that the clinical course of patients with HFE-HCC is more aggressive and provides the first data indicating that their tumours have increased expression of progenitor markers. These findings suggest patients with HFE-HCC may need to be considered for transplant at an earlier stage.

Consensus Statement on the definition and classification of metabolic hyperferritinaemia.

Hyperferritinaemia is a common laboratory finding that is often associated with metabolic dysfunction and fatty liver. Metabolic hyperferritinaemia reflects alterations in iron metabolism that facilitate iron accumulation in the body and is associated with an increased risk of cardiometabolic and liver diseases. Genetic variants that modulate iron homeostasis and tissue levels of iron are the main determinants of serum levels of ferritin in individuals with metabolic dysfunction, raising the hypothesis that iron accumulation might be implicated in the pathogenesis of insulin resistance and the related organ damage. However, validated criteria for the non-invasive diagnosis of metabolic hyperferritinaemia and the staging of iron overload are still lacking, and there is no clear evidence of a benefit for iron depletion therapy. Here, we provide an overview of the literature on the relationship between hyperferritinaemia and iron accumulation in individuals with metabolic dysfunction, and on the associated clinical outcomes. We propose an updated definition and a provisional staging system for metabolic hyperferritinaemia, which has been agreed on by a multidisciplinary global panel of expert researchers. The goal is to foster studies into the epidemiology, genetics, pathophysiology, clinical relevance and treatment of metabolic hyperferritinaemia, for which we provide suggestions on the main unmet needs, optimal design and clinically relevant outcomes.

An international multidisciplinary consensus statement on MAFLD and the risk of CVD.

BACKGROUND: Fatty liver disease in the absence of excessive alcohol consumption is an increasingly common condition with a global prevalence of ~ 25-30% and is also associated with cardiovascular disease (CVD). Since systemic metabolic dysfunction underlies its pathogenesis, the term metabolic (dysfunction)-associated fatty liver disease (MAFLD) has been proposed for this condition. MAFLD is closely intertwined with obesity, type 2 diabetes mellitus and atherogenic dyslipidemia, which are established cardiovascular risk factors. Unlike CVD, which has received attention in the literature on fatty liver disease, the CVD risk associated with MAFLD is often underestimated, especially among Cardiologists. METHODS AND RESULTS: A multidisciplinary panel of fifty-two international experts comprising Hepatologists, Endocrinologists, Diabetologists, Cardiologists and Family Physicians from six continents (Asia, Europe, North America, South America, Africa and Oceania) participated in a formal Delphi survey and developed consensus statements on the association between MAFLD and the risk of CVD. Statements were developed on different aspects of CVD risk, ranging from epidemiology to mechanisms, screening, and management. CONCULSIONS: The expert panel identified important clinical associations between MAFLD and the risk of CVD that could serve to increase awareness of the adverse metabolic and cardiovascular outcomes of MAFLD. Finally, the expert panel also suggests potential areas for future research.