ResearchPad - bile https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[A pilot study of ex-vivo MRI-PDFF of donor livers for assessment of steatosis and predicting early graft dysfunction]]> https://www.researchpad.co/article/elastic_article_14544 The utility of ex vivo Magnetic resonance imaging proton density fat fraction (MRI-PDFF) in donor liver fat quantification is unknown.PurposeTo evaluate the diagnostic accuracy and utility in predicting early allograft dysfunction (EAD) of ex vivo MRI-PDFF measurement of fat in deceased donor livers using histology as the gold standard.MethodsWe performed Ex vivo, 1.5 Tesla MRI-PDFF on 33 human deceased donor livers before implantation, enroute to the operating room. After the exclusion of 4 images (technical errors), 29 MRI images were evaluable. Histology was evaluable in 27 of 29 patients. EAD was defined as a peak value of aminotransferase >2000 IU/mL during the first week or an INR of ≥1.6 or bilirubin ≥10 mg/dL at day 7.ResultsMRI-PDFF values showed a strong positive correlation (Pearson’s correlation coefficient) when histology (macro-steatosis) was included (r = 0.78, 95% confidence interval 0.57‐0.89, p<0.0001). The correlation appeared much stronger when macro plus micro-steatosis were included (r = 0.87, 95% confidence interval 0.72‐0.94, p<0.0001). EAD was noted in 7(25%) subjects. AUC (Area Under the Curve) for macro steatosis (histology) predicted EAD in 73% (95% CI: 48–99), micro plus macro steatosis in 76% (95% CI: 49–100). AUC for PDFF values predicted EAD in 67(35–98). Comparison of the ROC curves in a multivariate model revealed, adding MRI PDFF values to macro steatosis increased the ability of the model in predicting EAD (AUC: 79%, 95% CI: 59–99), and addition of macro plus micro steatosis based on histology predicted EAD even better (AUC: 90%: 79–100, P = 0.054).ConclusionIn this pilot study, MRI-PDFF imaging showed potential utility in quantifying hepatic steatosis ex-vivo donor liver evaluation and the ability to predict EAD related to severe allograft steatosis in the recipient. ]]> <![CDATA[Improvement of steatotic rat liver function with a defatting cocktail during <i>ex situ</i> normothermic machine perfusion is not directly related to liver fat content]]> https://www.researchpad.co/article/elastic_article_13803 There is a significant organ shortage in the field of liver transplantation, partly due to a high discard rate of steatotic livers from donors. These organs are known to function poorly if transplanted but make up a significant portion of the available pool of donated livers. This study demonstrates the ability to improve the function of steatotic rat livers using a combination of ex situ machine perfusion and a “defatting” drug cocktail. After 6 hours of perfusion, defatted livers demonstrated lower perfusate lactate levels and improved bile quality as demonstrated by higher bile bicarbonate and lower bile lactate. Furthermore, defatting was associated with decreased gene expression of pro-inflammatory cytokines and increased expression of enzymes involved in mitochondrial fatty acid oxidation. Rehabilitation of marginal or discarded steatotic livers using machine perfusion and tailored drug therapy can significantly increase the supply of donor livers for transplantation.

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<![CDATA[Amino acids serve as an important energy source for adult flukes of <i>Clonorchis sinensis</i>]]> https://www.researchpad.co/article/elastic_article_13829 Clonorchiasis, closely related to cholangiocarcinoma and hepatocellular carcinoma, has led to a negative socioeconomic impact in global areas especially some Asian endemic regions. Owing to the emergence of drug resistance and hypersensitivity reactions after the massive and repeated use of praziquantel as well as the lack of effective vaccines, searching for new strategies that prevent and treat clonorchiasis has become an urgent matter. Clonorchis sinensis, the causative agent of clonorchiasis, long-term inhabits the microaerobic and limited-glucose environment of the bile ducts. Adequate nutrients are essential for adult flukes to resist the adverse condition and survive in the crowed habitat. Studies on energy metabolism of adult flukes are beneficial for further exploring host-parasite interactions and developing novel anti-parasitic drugs. Our results suggest that gluconeogenesis probably plays a vital role in energy metabolism of Clonorchis sinensis and exogenous amino acids might be an essential energy source for adult flukes to successfully survive in the host. Our foundational study opens a new avenue for explaining energy metabolism of Clonorchis sinensis and provides a valuable strategy that the gluconeogenesis pathway will be a potential and novel target for the prevention and treatment of clonorchiasis.

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<![CDATA[Severe hyperbilirubinemia is associated with higher risk of contrast-related acute kidney injury following contrast-enhanced computed tomography]]> https://www.researchpad.co/article/N624c57d4-8983-4ece-aecc-e0e7860066cf

Introduction

Contrast-induced acute kidney injury (CI-AKI) is associated with high risks of morbidity and mortality. Hyperbilirubinemia might have some renal protection but with no clear cutoff value for protection. Related studies are typically on limited numbers of patients and only in conditions of vascular intervention.

Methods

We performed this study to elucidate CI-AKI in patients after contrast-enhanced computed tomography (CCT). The outcomes were CI-AKI, dialysis and mortality. Patients were divided to three groups based on their serum levels of total bilirubin: ≤1.2 mg/dl, 1.3–2.0 mg/dl, and >2.0 mg/dl.

Results

We enrolled a total of 9,496 patients who had received CCT. Patients with serum total bilirubin >2.0 mg/dl were associated with CI-AKI. Those undergoing dialysis had the highest incidence of PC-AKI (p<0.001). No difference was found between the two groups of total bilirubin ≤1.2 and 1.3–2.0 mg/dl. Patients with total bilirubin >2mg/dl were associated with CI-AKI (OR = 1.89, 1.53–2.33 of 95% CI), dialysis (OR = 1.40, 1.01–1.95 of 95% CI) and mortality (OR = 1.63, 1.38–1.93 of 95% CI) after adjusting for laboratory data and all comorbidities (i.e., cerebrovascular disease, coronary artery disease, peripheral arterial disease, and acute myocardial infarction, diabetes mellitus, hypertension, gastrointestinal bleeding, cirrhosis, peritonitis, ascites, hepatoma, shock lung and colon cancer). We concluded that total bilirubin level >2 mg/dl is an independent risk factor for CI-AKI, dialysis and mortality after CCT. These patients also had high risks for cirrhosis or hepatoma.

Conclusion

This is the first study providing evidence that hyperbilirubinemia (total bilirubin >2.0 mg/dl) being an independent risk factor for CI-AKI, dialysis and mortality after receiving CCT. Most patients with total bilirubin >2.0mg/dl had cirrhosis or hepatoma.

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<![CDATA[The role of the erythrocyte in the outcome of pregnancy with preeclampsia]]> https://www.researchpad.co/article/5c897713d5eed0c4847d23cc

The objective of this study was to analyze the relationships of osmotic and mechanical stability of erythrocytes with anthropometric, biochemical, hematologic and hemodynamic variables in pregnant women with preeclampsia (PE). The studied population consisted of 20 normotensive patients and 16 patients with PE. Patients with PE presented worse gestational outcome, greater hematologic impairment, erythrocytes osmotically more stable in vitro, but in conditions of isotonicity with the in vivo medium, in addition to hyperflow in orbital territory, when compared to normotensive patients. The correlation analysis between anthropometric, hematologic and hemodynamic variables in patients with PE indicated that erythrocytes with lower volumes and lower levels of hemoglobin favor the occurrence of a better gestational outcome, because they are more stable and because they are associated with a decrease in the hemodynamic changes present in the disease. This should mean that the tendency to microcytosis, probably due to a mechanism of compensatory mechanical selection, is a desirable characteristic in the disease.

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<![CDATA[Understanding the prevalence of bear part consumption in Cambodia: A comparison of specialised questioning techniques]]> https://www.researchpad.co/article/5c76fdedd5eed0c484e5b0d5

The trade in bear parts for medicine and for status is a conservation challenge throughout Asia. The Asiatic black bear (Ursus thibetanus) and the sun bear (Helarctos malayanus) are endemic to this region, and populations are estimated to have declined throughout their ranges due to widespread illegal killing of bears and trade in parts, combined with loss of habitat. Previous studies have indicated that legislation alone is insufficient to prevent illegal hunting and trade, indicating instead a need to address demand for bear parts and products. We conducted mixed-method surveys in Cambodia to understand the key motivators for individuals to consume bear parts, and to understand whether specialised questioning techniques are applicable in this context. Bear part use is illegal in Cambodia and may therefore be considered a sensitive behaviour, in that individuals may be reluctant to admit to it. To counteract possible biases, four specialised questioning techniques were used in this study: randomised response technique (RRT), unmatched count technique (UCT), nominative technique (NT), and false consensus bias (FCB). All four methods serve to shield a respondent’s admittance of a sensitive behaviour from the interviewer. The results presented here show that great variability exists in anonymous methods’ efficacy in certain contexts. However, the results overall indicate that individuals in Cambodia are under-reporting their consumption of bear parts when directly asked, and that the prevalence of bear part use in Cambodia may be as high as 15% of the population, representing a significant conservation challenge.

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<![CDATA[Development of a risk prediction model (Hangang) and comparison with clinical severity scores in burn patients]]> https://www.researchpad.co/article/5c648ce4d5eed0c484c81a27

Purpose

The purpose of this study was to develop a new prediction model to reflect the risk of mortality and severity of disease and to evaluate the ability of the developed model to predict mortality among adult burn patients.

Methods

This study included 2009 patients aged more than 18 years who were admitted to the intensive care unit (ICU) within 24 hours after a burn. We divided the patients into two groups; those admitted from January 2007 to December 2013 were included in the derivation group and those admitted from January 2014 to September 2017 were included in the validation group. Shrinkage methods with 10-folds cross-validation were performed to identify variables and limit overfitting of the model. The discrimination was analyzed using the area under the curve (AUC) of the receiver operating characteristic curve. The Brier score, integrated discrimination improvement (IDI), and net reclassification improvement (NRI) were also calculated. The calibration was analyzed using the Hosmer-Lemeshow goodness-of-fit test (HL test). The clinical usefulness was evaluated using a decision-curve analysis.

Results

The Hangang model showed good calibration with the HL test (χ2 = 8.785, p = 0.361); the highest AUC and the lowest Brier score were 0.943 and 0.068, respectively. The NRI and IDI were 0.124 (p-value = 0.003) and 0.079 (p-value <0.001) when compared with FLAMES, respectively.

Conclusions

This model reflects the current risk factors of mortality among adult burn patients. Furthermore, it was a highly discriminatory and well-calibrated model for the prediction of mortality in this cohort.

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<![CDATA[Prediction of all-cause mortality after liver transplantation using left ventricular systolic and diastolic function assessment]]> https://www.researchpad.co/article/5c79afc8d5eed0c4841e3741

Although pretransplant cardiac dysfunction is considered a major predictor of poor outcomes after liver transplantation (LT), the ability of left ventricular (LV) systolic/diastolic function (LVSF/LVDF), together or individually, to predict mortality after LT is poorly characterized. We retrospectively evaluated pretransplant clinical and Doppler echocardiographic data of 839 consecutive LT recipients from 2009 to 2012 aged 18–60 years. The primary endpoint was all-cause mortality at 4 years. The overall survival rate was 91.2%. In multivariate Cox analysis, reduced LV ejection fraction (LVEF, P = 0.014) and decreased transmitral E/A ratio(P = 0.022) remained significant prognosticators. In LVSF analysis, patients with LVEF≤60% (quartile [Q]1) had higher mortality than those with LVEF>60% (hazard ratio = 1.90, 95% confidence interval = 1.15–3.15, P = 0.012). In LVDF analysis, patients with an E/A ratio<0.9(Q1) had a 2.19-fold higher risk of death (95% confidence interval = 1.11–4.32, P = 0.024) than those with an E/A ratio>1.4(Q4). In combined LVDF and LVSF analysis, patients with an E/A ratio<0.9 and LVEF≤60% had poorer survival outcomes than patients with an E/A ratio≥0.9 and LVEF>60% (79.5% versus 93.3%, P = 0.001). Patients with an early mitral inflow velocity/annular velocity (E/e’ ratio)>11.5(Q4) and LV stroke volume index (LVSVI)<33mL/m2(Q1) showed worse survival than those with an E/e’ ratio≤11.5 and LVSVI ≥33mL/m2(78.4% versus 92.2%, P = 0.003). A combination of LVSF and LVDF is a better predictor of survival than LVSF or LVDF alone.

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<![CDATA[Dynamic distribution of gallbladder microbiota in rabbit at different ages and health states]]> https://www.researchpad.co/article/5c61e8fed5eed0c48496f5f4

The internal environment of the gallbladder has been considered extremely unfavorable for bacterial growth, and the microbial profile of the gallbladder still unknown. By high-throughput sequencing of the bacterial 16S rRNA gene, we studied the microbial profile of the gallbladder from healthy rabbits before and after weaning. Moreover, we investigated the difference of microbiota between the gallbladder and gut. Our results showed that the gallbladder was dominantly populated by Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria in the phylum throughout the developmental stages of rabbits. The adult rabbits showed higher species richness and exhibited higher bacterial diversity than rabbits before weaning based on the results of alpha diversity. Beta diversity analyses indicated differences in the bacterial community composition between different developmental stages. In the comparison of the gallbladder and feces, Firmicutes and Bacteroidetes were dominant in the phylum, as they were present in about 61% and 21% of the feces, respectively. Conversely, in the gallbladder, Firmicutes was the most dominant (about 41%), and Bacteroidetes and Proteobacteria were present in about 16% and 22% of the gallbladder, respectively. The Unweighted UniFrac Principal Coordinate Analysis results illustrated samples clustered into 2 categories: the gallbladder and feces. Our study might provide a foundation for knowledge on gallbladder microbiota for the first time and a basis for further studies on gallbladder and intestinal health.

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<![CDATA[Dietary calcium affects body composition and lipid metabolism in rats]]> https://www.researchpad.co/article/5c40f821d5eed0c484387137

Calcium (Ca) intakes may affect cardiovascular disease risk by altering body composition (body weight and fat) and serum lipid profile, but results have been inconsistent and the underlying mechanisms are not well understood. The effects of dietary Ca on body composition and lipid metabolism were examined in rats. Male Sprague-Dawley rats were fed high-fat, high-energy diets containing (g/kg) low (0.75Ca, 0.86 ± 0.05; 2Ca, 2.26 ± 0.02), normal (5Ca, 5.55 ± 0.08) or high (10Ca, 11.03 ± 0.17; 20Ca, 21.79 ± 0.15) Ca for 10 weeks. Rats fed the lowest Ca diet (0.75Ca) had lower (p < 0.05) body weight and fat mass compared to other groups. Rats fed the high Ca diets had lower serum total and LDL cholesterol compared to rats fed normal or low Ca. Liver total cholesterol was lower in rats fed high compared to low Ca. In general, liver mRNA expression of genes involved in cholesterol uptake from the circulation (Ldlr), cholesterol synthesis (Hmgcr and Hmgcs1), fatty acid oxidation (Cpt2) and cholesterol esterification (Acat2) were higher in rats fed higher Ca. Apparent digestibility of total trans, saturated, monounsaturated and polyunsaturated fatty acids was lower in rats fed the high compared to the low Ca diets, with the largest effects seen on trans and saturated fatty acids. Fecal excretion of cholesterol and total bile acids was highest in rats fed the highest Ca diet (20Ca). The results suggest little effect of dietary Ca on body composition unless Ca intakes are very low. Decreased bile acid reabsorption and reduced absorption of neutral sterols and saturated and trans fatty acids may contribute to the better serum lipid profile in rats fed higher Ca.

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<![CDATA[ERCP in infants, children, and adolescents—Different roles of the methods in different age groups]]> https://www.researchpad.co/article/5c61b7c3d5eed0c484937f57

Background

Endoscopic retrograde cholangiopancreatography (ERCP) is seldom used in children, and published series have limited numbers of pediatric patients. The aim of this retrospective observational study was to assess the efficacy and safety of pediatric ERCP in a large group of children.

Methods

Data were evaluated from 626 children with biliopancreatic disorders admitted to University Hospital Motol, Prague, between January 1999 and January 2018. Clinical data were obtained by retrospective evaluation of our database of pediatric ERCP procedures and from clinical records.

Results

We performed 856 ERCPs on 626 pediatric patients; of these procedures, 59% were therapeutic and 41% were diagnostic. We achieved 96% technical success. Indications for ERCP and pathological findings differed in different age groups. The main role of ERCP was in excluding biliary atresia in those aged less than one year. In children aged 1 to 6 years, the most frequent diagnoses were choledochal cyst followed by choledocholithiasis. In children aged 7 to 12 years and 13 to 19 years, the most frequent diagnoses were choledocholithiasis followed by pancreatic pathology. The overall complication rate found in this study was similar to rates observed in adult populations.

Conclusions

Our study shows the efficacy and safety of diagnostic and therapeutic ERCP in a large series of infants and children with technical success and complication rates comparable to those in adults. Our data show that ERCP had different roles in different age groups of children.

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<![CDATA[Metabolomics and 16S rRNA sequencing of human colorectal cancers and adjacent mucosa]]> https://www.researchpad.co/article/5c269780d5eed0c48470fb79

Colorectal cancer (CRC) is ranked the third most common cancer in human worldwide. However, the exact mechanisms of CRC are not well established. Furthermore, there may be differences between mechanisms of CRC in the Asian and in the Western populations. In the present study, we utilized a liquid chromatography-mass spectrometry (LC-MS) metabolomic approach supported by the 16S rRNA next-generation sequencing to investigate the functional and taxonomical differences between paired tumor and unaffected (normal) surgical biopsy tissues from 17 Malaysian patients. Metabolomic differences associated with steroid biosynthesis, terpenoid biosynthesis and bile metabolism could be attributed to microbiome differences between normal and tumor sites. The relative abundances of Anaerotruncus, Intestinimonas and Oscillibacter displayed significant relationships with both steroid biosynthesis and terpenoid and triterpenoid biosynthesis pathways. Metabolites involved in serotonergic synapse/ tryptophan metabolism (Serotonin and 5-Hydroxy-3-indoleacetic acid [5-HIAA]) were only detected in normal tissue samples. On the other hand, S-Adenosyl-L-homocysteine (SAH), a metabolite involves in methionine metabolism and methylation, was frequently increased in tumor relative to normal tissues. In conclusion, this study suggests that local microbiome dysbiosis may contribute to functional changes at the cancer sites. Results from the current study also contributed to the list of metabolites that are found to differ between normal and tumor sites in CRC and supported our quest for understanding the mechanisms of carcinogenesis.

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<![CDATA[Serum IP-10 levels and increased DPPIV activity are linked to circulating CXCR3+ T cells in cholestatic HCV patients]]> https://www.researchpad.co/article/5c0ed777d5eed0c484f141d9

Background & aims

Serum interferon-gamma-inducible protein-10 (IP-10) is elevated in cholestatic liver diseases and predicts response to antiviral therapy in patients with chronic hepatitis C virus (HCV) infection. Dipeptidylpeptidase 4 (DPPIV) cleaves active IP-10 into an inactive form, which inhibits recruitment of CXCR3+ T cells to the liver. In this study the link between IP-10 levels, DPPIV activity in serum and CXCR3+ T cells is analysed in cholestatic and non-cholestatic liver patients.

Methods

In serum DPPIV activity (by enzymatic assay), IP-10 (by ELISA) and bile acids (BA) (by enzymatic assay) were analysed in 229 naive HCV genotype (GT) 1 patients and in 16 patients with cholestatic liver disease. In a prospective follow-up (FU) cohort of 27 HCV GT 1 patients peripheral CD3+CXCR3+, CD4+CXCR3+ and CD8+CXCR3+ cells were measured by FACS.

Results

In 229 HCV patients serum IP-10 levels correlated positively to DPPIV serum activity. Higher IP-10 levels and DPPIV activity were detected in cholestatic and in cirrhotic HCV patients. Increased IP-10 serum levels were associated with therapeutic non-response to antiviral treatment with pegylated-interferon and ribavirin. In the HCV FU cohort elevated IP-10 serum levels and increased BA were associated with higher frequencies of peripheral CD3+CXCR3+, CD4+CXCR3+ and CD8+CXCR3+ T cells. Positive correlation between serum IP-10 levels and DPPIV activity was likewise validated in patients with cholestatic liver diseases.

Conclusions

A strong correlation between elevated serum levels of IP-10 and DPPIV activity was seen in different cholestatic patient groups. Furthermore, in cholestatic HCV patients a functional link to increased numbers of peripheral CXCR3+ immune cells could be observed. The source of DPPIV release in cholestatic patients remains open.

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<![CDATA[Radiation exposure dose and influencing factors during endoscopic retrograde cholangiopancreatography]]> https://www.researchpad.co/article/5bfc627dd5eed0c484ec99e4

Introduction

Various endoscopic procedures under fluoroscopic guidance are being rapidly adopted, and radiation exposure is considered to be increasing. However, there is little concern about this issue in gastroenterology practice. This study aims to evaluate the actual radiation exposure dose (RD) during endoscopic retrograde cholangiopancreatography (ERCP) and the factors affecting the RD.

Methods

In this retrospective, single-center cohort study of 1157 consecutive patients who underwent ERCP between October 2012 and February 2017, we analyzed the influences of patient characteristics, procedure time (min), total fluoroscopy time (min), type of processing engine, experience of the endoscopist, and type of disease on the total RD (mGy).

Results

The median procedure times were 28 min for common bile duct stones (CBDS), 25 min for distal malignant biliary obstruction (MBO), and 30 min for proximal MBO. Similarly, the median fluoroscopy times were 10.3, 8.8, and 13.4 min, and the median RDs were 167, 123, and 242 mGy, respectively. Proximal MBO required significantly longer procedure time and fluoroscopy time and resulted in greater RD than distal MBO (P = 0.0006, <0.0001, <0.0001) and CBDS (P = 0.015, <0.0001, <0.0001). Multiple linear regression showed that distal MBO and a novel processing engine negatively correlate with RD (P = 0.04, <0.0001) and that proximal MBO positively correlates with RD (P = 0.0001).

Discussion

Procedure time and fluoroscopy time were significantly longer for proximal MBO than for CBDS and distal MBO. The type of disease and processing engine significantly influenced the RD during ERCP.

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<![CDATA[Characterisation of the hepatitis B virus cross-species transmission pattern via Na+/taurocholate co-transporting polypeptides from 11 New World and Old World primate species]]> https://www.researchpad.co/article/5b498fae463d7e0897c6e01e

The hepatic Na+/taurocholate co-transporting polypeptide (NTCP in man, Ntcp in animals) is the high-affinity receptor for the hepatitis B (HBV) and hepatitis D (HDV) viruses. Species barriers for human HBV/HDV within the order Primates were previously attributed to Ntcp sequence variations that disable virus-receptor interaction. However, only a limited number of primate Ntcps have been analysed so far. In the present study, a total of 11 Ntcps from apes, Old and New World monkeys were cloned and expressed in vitro to characterise their interaction with HBV and HDV. All Ntcps showed intact bile salt transport. Human NTCP as well as the Ntcps from the great apes chimpanzee and orangutan showed transport-competing binding of HBV derived myr-preS1-peptides. In contrast, all six Ntcps from the group of Old World monkeys were insensitive to HBV myr-preS1-peptide binding and HBV/HDV infection. This is basically predetermined by the amino acid arginine at position 158 of all studied Old World monkey Ntcps. An exchange from arginine to glycine (as present in humans and great apes) at this position (R158G) alone was sufficient to achieve full transport-competing HBV myr-preS1-peptide binding and susceptibility for HBV/HDV infection. New World monkey Ntcps showed higher sequence heterogeneity, but in two cases with 158G showed transport-competing HBV myr-preS1-peptide binding, and in one case (Saimiri sciureus) even susceptibility for HBV/HDV infection. In conclusion, amino acid position 158 of NTCP/Ntcp is sufficient to discriminate between the HBV/HDV susceptible group of humans and great apes (158G) and the non-susceptible group of Old World monkeys (158R). In the case of the phylogenetically more distant New World monkey Ntcps amino acid 158 plays a significant, but not exclusive role.

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<![CDATA[Development and Evaluation of a Blood Culture PCR Assay for Rapid Detection of Salmonella Paratyphi A in Clinical Samples]]> https://www.researchpad.co/article/5989da75ab0ee8fa60b963a7

Background

Enteric fever remains an important cause of morbidity in many low-income countries and Salmonella Paratyphi A has emerged as the aetiological agent in an increasing proportion of cases. Lack of adequate diagnostics hinders early diagnosis and prompt treatment of both typhoid and paratyphoid but development of assays to identify paratyphoid has been particularly neglected. Here we describe the development of a rapid and sensitive blood culture PCR method for detection of Salmonella Paratyphi A from blood, potentially allowing for appropriate diagnosis and antimicrobial treatment to be initiated on the same day.

Methods

Venous blood samples from volunteers experimentally challenged orally with Salmonella Paratyphi A, who subsequently developed paratyphoid, were taken on the day of diagnosis; 10 ml for quantitative blood culture and automated blood culture, and 5 ml for blood culture PCR. In the latter assay, bacteria were grown in tryptone soy broth containing 2.4% ox bile and micrococcal nuclease for 5 hours (37°C) before bacterial DNA was isolated for PCR detection targeting the fliC-a gene of Salmonella Paratyphi A.

Results

An optimized broth containing 2.4% ox bile and micrococcal nuclease, as well as a PCR test was developed for a blood culture PCR assay of Salmonella Paratyphi A. The volunteers diagnosed with paratyphoid had a median bacterial burden of 1 (range 0.1–6.9) CFU/ml blood. All the blood culture PCR positive cases where a positive bacterial growth was shown by quantitative blood culture had a bacterial burden of ≥ 0.3 CFU/ ml blood. The blood culture PCR assay identified an equal number of positive cases as automated blood culture at higher bacterial loads (≥0.3 CFU/ml blood), but utilized only half the volume of specimens.

Conclusions

The blood culture PCR method for detection of Salmonella Paratyphi A can be completed within 9 hours and offers the potential for same-day diagnosis of enteric fever. Using 5 ml blood, it exhibited a lower limit of detection equal to 0.3 CFU/ml blood, and it performed at least as well as automated blood culture at higher bacterial loads (≥0.3 CFU/ml blood) of clinical specimens despite using half the volume of blood. The findings warrant its further study in endemic populations with a potential use as a novel diagnostic which fills the present gap of paratyphoid diagnostics.

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<![CDATA[Bile Acids and Dysbiosis in Non-Alcoholic Fatty Liver Disease]]> https://www.researchpad.co/article/5989d9f6ab0ee8fa60b701f0

Background & Aims

Non-alcoholic fatty liver disease (NAFLD) is characterized by dysbiosis. The bidirectional effects between intestinal microbiota (IM) and bile acids (BA) suggest that dysbiosis may be accompanied by an altered bile acid (BA) homeostasis, which in turn can contribute to the metabolic dysregulation seen in NAFLD. This study sought to examine BA homeostasis in patients with NAFLD and to relate that with IM data.

Methods

This was a prospective, cross-sectional study of adults with biopsy-confirmed NAFLD (non-alcoholic fatty liver: NAFL or non-alcoholic steatohepatitis: NASH) and healthy controls (HC). Clinical and laboratory data, stool samples and 7-day food records were collected. Fecal BA profiles, serum markers of BA synthesis 7-alpha-hydroxy-4-cholesten-3-one (C4) and intestinal BA signalling, as well as IM composition were assessed.

Results

53 subjects were included: 25 HC, 12 NAFL and 16 NASH. Levels of total fecal BA, cholic acid (CA), chenodeoxycholic acid (CDCA) and BA synthesis were higher in patients with NASH compared to HC (p<0.05 for all comparisons). The primary to secondary BA ratio was higher in NASH compared to HC (p = 0.004), but ratio of conjugated to unconjugated BAs was not different between the groups. Bacteroidetes and Clostridium leptum counts were decreased in in a subset of 16 patients with NASH compared to 25 HC, after adjusting for body mass index and weight-adjusted calorie intake (p = 0.028 and p = 0.030, respectively). C. leptum was positively correlated with fecal unconjugated lithocholic acid (LCA) (r = 0.526, p = 0.003) and inversely with unconjugated CA (r = -0.669, p<0.0001) and unconjugated CDCA (r = - 0.630, p<0.0001). FGF19 levels were not different between the groups (p = 0.114).

Conclusions

In adults with NAFLD, dysbiosis is associated with altered BA homeostasis, which renders them at increased risk of hepatic injury.

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<![CDATA[Lack of the PGA exopolysaccharide in Salmonella as an adaptive trait for survival in the host]]> https://www.researchpad.co/article/5989db5cab0ee8fa60be0197

Many bacteria build biofilm matrices using a conserved exopolysaccharide named PGA or PNAG (poly-β-1,6-N-acetyl-D-glucosamine). Interestingly, while E. coli and other members of the family Enterobacteriaceae encode the pgaABCD operon responsible for PGA synthesis, Salmonella lacks it. The evolutionary force driving this difference remains to be determined. Here, we report that Salmonella lost the pgaABCD operon after the divergence of Salmonella and Citrobacter clades, and previous to the diversification of the currently sequenced Salmonella strains. Reconstitution of the PGA machinery endows Salmonella with the capacity to produce PGA in a cyclic dimeric GMP (c-di-GMP) dependent manner. Outside the host, the PGA polysaccharide does not seem to provide any significant benefit to Salmonella: resistance against chlorine treatment, ultraviolet light irradiation, heavy metal stress and phage infection remained the same as in a strain producing cellulose, the main biofilm exopolysaccharide naturally produced by Salmonella. In contrast, PGA production proved to be deleterious to Salmonella survival inside the host, since it increased susceptibility to bile salts and oxidative stress, and hindered the capacity of S. Enteritidis to survive inside macrophages and to colonize extraintestinal organs, including the gallbladder. Altogether, our observations indicate that PGA is an antivirulence factor whose loss may have been a necessary event during Salmonella speciation to permit survival inside the host.

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<![CDATA[Epidemiology and Resistance Patterns of Bacterial and Fungal Colonization of Biliary Plastic Stents: A Prospective Cohort Study]]> https://www.researchpad.co/article/5989da25ab0ee8fa60b8081b

Background

Plastic stents used for the treatment of biliary obstruction will become occluded over time due to microbial colonization and formation of biofilms. Treatment of stent-associated cholangitis is often not effective because of inappropriate use of antimicrobial agents or antimicrobial resistance. We aimed to assess the current bacterial and fungal etiology of stent-associated biofilms, with particular emphasis on antimicrobial resistance.

Methods

Patients with biliary strictures requiring endoscopic stent placement were prospectively enrolled. After the retrieval of stents, biofilms were disrupted by sonication, microorganisms were cultured, and isolates were identified by matrix-associated laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and/or biochemical typing. Finally, minimum inhibitory concentrations (MICs) were determined for various antimicrobial agents. Selected stents were further analyzed by fluorescence in situ hybridization (FISH).

Results

Among 120 patients (62.5% males, median age 64 years) with biliary strictures (35% malignant, 65% benign), 113 double pigtail polyurethane and 100 straight polyethylene stents were analyzed after a median indwelling time of 63 days (range, 1–1274 days). The stent occlusion rate was 11.5% and 13%, respectively, being associated with a significantly increased risk of cholangitis (38.5% vs. 9.1%, P<0.001). Ninety-five different bacterial and 13 fungal species were detected; polymicrobial colonization predominated (95.8% vs. 4.2%, P<0.001). Enterococci (79.3%), Enterobacteriaceae (73.7%), and Candida spp. (55.9%) were the leading pathogens. Candida species were more frequent in patients previously receiving prolonged antibiotic therapy (63% vs. 46.7%, P = 0.023). Vancomycin-resistant enterococci accounted for 13.7%, extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae with co-resistance to ciprofloxacin accounted for 13.9%, and azole-resistant Candida spp. accounted for 32.9% of the respective isolates.

Conclusions

Enterococci and Candida species play an important role in the microbial colonization of biliary stents. Therefore, empirical antimicrobial treatment of stent-associated cholangitis should be guided toward enterococci, Enterobacteriaceae, streptococci, anaerobes, and Candida. To determine causative pathogens, an accurate microbiological analysis of the extracted stent(s) may be helpful.

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<![CDATA[Elevated bilirubin levels are associated with a better renal prognosis and ameliorate kidney fibrosis]]> https://www.researchpad.co/article/5989db4fab0ee8fa60bdbbd2

Background

Bilirubin has been reported to protect against kidney injury. However, further studies highlighting the beneficial effects of bilirubin on renal fibrosis and chronic renal function decline are necessary.

Methods

We assessed a prospective cohort with a reference range of total bilirubin levels. The primary outcome was a 30% reduction in the estimated glomerular filtration rate (eGFR) from baseline, and the secondary outcome was a doubling of the serum creatinine levels, halving of the eGFR and the initiation of dialysis. In addition, experiments with tubular epithelial cells and C57BL/6 mice were performed to investigate the protective effects of bilirubin on kidney fibrosis.

Results

As a result, 1,080 patients were included in the study cohort. The study group with relative hyperbilirubinemia (total bilirubin 0.8–1.2 mg/dL) showed a better prognosis in terms of the primary outcome (adjusted hazard ratio (HR) 0.33, 95% confidence interval (CI) 0.19–0.59, P < 0.001) and the secondary outcome (adjusted HR 0.20, 95% CI 0.05 to 0.71, P = 0.01) than that of the control group. Moreover, the bilirubin-treated mice showed less fibrosis in the unilateral ureteral obstruction (UUO) model (P < 0.05). In addition, bilirubin treatment decreased fibronectin expression in tubular epithelial cells in a dose-dependent manner (P < 0.05).

Conclusions

Mildly elevated serum bilirubin levels were associated with better renal prognosis, and bilirubin treatment induced a beneficial effect on renal fibrosis. Therefore, bilirubin could be a potential therapeutic target to delay fibrosis-related kidney disease progression.

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