Determining bone turnover status in patients with chronic liver disease

Introduction: Hepatic osteodystrophy is an osteoporotic bone disease that occurs in chronic liver disease patients. The global prevalence of osteoporosis in patients with chronic liver disease is 30% to 40%. The pathogenesis of hepatic bone disease is not clear, but it occurs due to unstable bone remodeling with increased bone resorption and decreases bone formation. There has been an interest in determining the clinical utility of bone turnover markers (BTMs) in the assessment of osteoporosis in chronic liver patients.Methods: This was a cross-sectional study conducted in patients with chronic liver disease at the section of chemical pathology, department of pathology and laboratory medicine, Aga Khan University (AKU). A total of 50 patients with age \u3e8 years and a history of liver disease \u3e6 months were recruited from January to October 2019. Liver function tests, i.e. aspartate aminotransferase (AST), alanine transaminase (ALT), albumin, and bilirubin, along with clinical signs of liver disease chronicity, were noted. The samples for BTMs, i.e. total serum alkaline phosphatase (ALP) and serum C-terminal telopeptide of type-1 collagen (CTX) were withdrawn and analyzed on Microlab (ELItech Group, Puteaux, France) and ADVIA Centaur (Siemens Diagnostics, NY), respectively.Results: The majority of patients were males (n=34, 68%). Twenty-four (48%) patients suffered from fibrosis while 26 (52%) were without fibrosis. Median platelet count (68×109/L (102.5-50)) and median cholesterol levels (102.5 mg/dl (147-99.5)) were decreased, whereas gamma-glutamyl transferase (GGT) levels were higher in the fibrosis group as compared to the non-fibrosis group. The median levels of total ALP were 91.5 IU/L (103-82), and the median levels of CTX were 0.24 pg/ml (0.34-0.21).Conclusion: In the present study, no significant difference was found in the BTMs of patients with and without chronic liver disease (CLD). However, there was a positive and significant correlation of BTMs, particularly CTX with age, bilirubin levels, and hepatomegaly

Mechanism of foreign DNA recognition by a CRISPR RNA-guided surveillance complex from Pseudomonas aeruginosa

The Type I-F CRISPR-mediated (clustered regularly interspaced short palindromic repeats) adaptive immune system in Pseudomonas aeruginosa consists of two CRISPR loci and six CRISPR-associated (cas) genes. Foreign DNA surveillance is performed by a complex of Cas proteins (Csy1-4) that assemble with a CRISPR RNA (crRNA) into a 350-kDa ribonucleoprotein called the Csy complex. Here, we show that foreign nucleic acid recognition by the Csy complex proceeds through sequential steps, initiated by detection of two consecutive guanine-cytosine base pairs (G-C/G-C) located adjacent to the complementary DNA target. We show that this motif, called the PAM (protospacer adjacent motif), must be double-stranded and that single-stranded PAMs do not provide significant discriminating power. Binding assays performed with G-C/G-C-rich competitor sequences indicate that the Csy complex interacts directly with this dinucleotide motif, and kinetic analyses reveal that recognition of a G-C/G-C motif is a prerequisite for crRNA-guided binding to a target sequence. Together, these data indicate that the Csy complex first interacts with G-C/G-C base pairs and then samples adjacent target sequences for complementarity to the crRNA guid

IceCube -- Neutrinos in Deep Ice The Top 3 Solutions from the Public Kaggle Competition

During the public Kaggle competition "IceCube -- Neutrinos in Deep Ice", thousands of reconstruction algorithms were created and submitted, aiming to estimate the direction of neutrino events recorded by the IceCube detector. Here we describe in detail the three ultimate best, award-winning solutions. The data handling, architecture, and training process of each of these machine learning models is laid out, followed up by an in-depth comparison of the performance on the kaggle datatset. We show that on cascade events in IceCube above 10 TeV, the best kaggle solution is able to achieve an angular resolution of better than 5 degrees, and for tracks correspondingly better than 0.5 degrees. These performance measures compare favourably to the current state-of-the-art in the field

Diagnostic accuracy of the forns score for liver cirrhosis in patients with chronic viral hepatitis

Introduction: Liver cirrhosis is an irreversible and end-stage disease. It results from chronic liver damage characterized by the replacement of normal liver tissue by fibrosis, leading to the progressive loss of liver function. Making an early diagnosis of cirrhosis is important for patients with chronic hepatitis because early antiviral therapy can prevent the progression of cirrhosis and even induce regression. There have been efforts to develop surrogate markers for liver cirrhosis as the biopsy is invasive, costly, and difficult to standardize.Methods: This was a cross-sectional study conducted at the Section of Chemical Pathology, the Department of Pathology and Laboratory Medicine in Collaboration with the Section of Gastroenterology, Department of Medicine, the Aga Khan University, from January to December 2018. A total of 90 patients (\u3e18 years of age) with a history of chronic viral hepatitis, who were attending the FibroScan® (Echosens, Paris, France) clinic were included. Patients with a history of autoimmune liver diseases and hepatocellular carcinoma were excluded from the study. Blood samples withdrawn were analyzed on ADVIA Centaur® (Siemens Healthineers, Erlangen, Germany), and Forns scores were calculated based on the following four parameters: patient age, total cholesterol, gamma-glutamyl transferase (GGT), and platelet count.Results: The median age of the patients was 38.5 years [interquartile range (IQR): 21]. Among the study population, 59 (65.6%) were males and 31 (34.4%) were females; 26 patients showed reactivity for hepatitis B surface antigen (HBsAg), and 63 patients were found chronic with hepatitis C virus (HCV). The proportion of HCV was observed to be higher as compared with that of Hepatitis B virus (HBV). Nineteen patients were found to have jaundice and only one patient had ascites. An Area Under the Receiver Operating Curve (AUROC) was generated to determine the diagnostic accuracy of the Forns score. It was observed that the Forn score value of \u3e7.110 had an AUROC of 0.9928 (95% CI: 0.9821-1.003, p-value: Conclusion: This study found the Forns score to be sensitive and specific in diagnosing liver cirrhosis in patients with chronic hepatitis. The Forns score at a cutoff of 7.11 is highly sensitive as well as a specific noninvasive method that can be used to ascertain the status of fibrosis in chronic hepatitis patients

Novel Normalization Standard using Fluorescence

The Biotec_Dresden Team 2010 developed an approach where two fluorescent proteins are simultaneously expressed. The fact that one reporter, in our case RFP, is constitutively expressed allows to monitor cell growth. Secondly, an inducible promoter drives the expression of the second reporter, YFP in the case of the part tested. The constitutively expressed reporter protein (R1) serves as normalization factor for the inducible reporter (R2) by simple division

Maize Adaptability to Heat Stress under Changing Climate

The rapidly increasing human population is an alarming issue and would need more food production under changing climate. Abiotic stresses like heat stress and temperature fluctuation are becoming key issues to be addressed for boosting crop production. Maize growth and productivity are sensitive to temperature fluctuations. Grain yield losses in maize from heat stress are expected to increase owing to higher temperatures during the growing season. This situation demands the development of maize hybrids tolerant to heat and drought stresses without compromising grain yield under stress conditions. The chapter aimed to assess the updates on the influence of high-temperature stress (HTS) on the physio-biochemical processes in plants and to draw an association between yield components and heat stress on maize. Moreover, exogenous applications of protectants, antioxidants, and signaling molecules induce HTS tolerance in maize plants and could help the plants cope with HTS by scavenging reactive oxygen species, upregulation of antioxidant enzymes, and protection of cellular membranes by the accrual of compatible osmolytes. It is expected that a better thought of the physiological basis of HTS tolerance in maize plants will help to develop HTS maize cultivars. Developing HTS-tolerant maize varieties may ensure crops production sustainability along with promoting food and feed security under changing climate

Effect of early tranexamic acid administration on mortality, hysterectomy, and other morbidities in women with post-partum haemorrhage (WOMAN): an international, randomised, double-blind, placebo-controlled trial

Background Post-partum haemorrhage is the leading cause of maternal death worldwide. Early administration of tranexamic acid reduces deaths due to bleeding in trauma patients. We aimed to assess the effects of early administration of tranexamic acid on death, hysterectomy, and other relevant outcomes in women with post-partum haemorrhage. Methods In this randomised, double-blind, placebo-controlled trial, we recruited women aged 16 years and older with a clinical diagnosis of post-partum haemorrhage after a vaginal birth or caesarean section from 193 hospitals in 21 countries. We randomly assigned women to receive either 1 g intravenous tranexamic acid or matching placebo in addition to usual care. If bleeding continued after 30 min, or stopped and restarted within 24 h of the first dose, a second dose of 1 g of tranexamic acid or placebo could be given. Patients were assigned by selection of a numbered treatment pack from a box containing eight numbered packs that were identical apart from the pack number. Participants, care givers, and those assessing outcomes were masked to allocation. We originally planned to enrol 15 000 women with a composite primary endpoint of death from all-causes or hysterectomy within 42 days of giving birth. However, during the trial it became apparent that the decision to conduct a hysterectomy was often made at the same time as randomisation. Although tranexamic acid could influence the risk of death in these cases, it could not affect the risk of hysterectomy. We therefore increased the sample size from 15 000 to 20 000 women in order to estimate the effect of tranexamic acid on the risk of death from post-partum haemorrhage. All analyses were done on an intention-to-treat basis. This trial is registered with ISRCTN76912190 (Dec 8, 2008); ClinicalTrials.gov, number NCT00872469; and PACTR201007000192283. Findings Between March, 2010, and April, 2016, 20 060 women were enrolled and randomly assigned to receive tranexamic acid (n=10 051) or placebo (n=10 009), of whom 10 036 and 9985, respectively, were included in the analysis. Death due to bleeding was significantly reduced in women given tranexamic acid (155 [1·5%] of 10 036 patients vs 191 [1·9%] of 9985 in the placebo group, risk ratio [RR] 0·81, 95% CI 0·65–1·00; p=0·045), especially in women given treatment within 3 h of giving birth (89 [1·2%] in the tranexamic acid group vs 127 [1·7%] in the placebo group, RR 0·69, 95% CI 0·52–0·91; p=0·008). All other causes of death did not differ significantly by group. Hysterectomy was not reduced with tranexamic acid (358 [3·6%] patients in the tranexamic acid group vs 351 [3·5%] in the placebo group, RR 1·02, 95% CI 0·88–1·07; p=0·84). The composite primary endpoint of death from all causes or hysterectomy was not reduced with tranexamic acid (534 [5·3%] deaths or hysterectomies in the tranexamic acid group vs 546 [5·5%] in the placebo group, RR 0·97, 95% CI 0·87-1·09; p=0·65). Adverse events (including thromboembolic events) did not differ significantly in the tranexamic acid versus placebo group. Interpretation Tranexamic acid reduces death due to bleeding in women with post-partum haemorrhage with no adverse effects. When used as a treatment for postpartum haemorrhage, tranexamic acid should be given as soon as possible after bleeding onset. Funding London School of Hygiene & Tropical Medicine, Pfizer, UK Department of Health, Wellcome Trust, and Bill & Melinda Gates Foundation

Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified

Evolution and mechanism of fatty acid synthase multienzymes

Fatty acids are central components of biological membranes, serve as energy storage compounds, and act as second messengers or as covalent modifiers governing protein localization. Biosynthesis of fatty acids uses a conserved mechanism across all species and is carried out in repeated cycles of reactions. In Eukaryotes, these reactions are catalyzed by type I fatty acid synthases (FAS), large architecturally diverse, multienzyme complexes that integrate all steps of fatty acid synthesis into complex biosynthetic assemblies. Two strikingly different types of FAS have emerged in fungi and in animals. The fungal FAS is a rigid, 2.6-MDa barrel- shaped structure with its 48 functional domains embedded in a matrix of scaffolding elements, which comprises almost 50% of the total sequence and determines the emergent multienzymes properties of fFAS. All functional core domains of fFAS are derived from monofunctional bacterial enzymes, but the evolutionary origin of the scaffolding elements remains enigmatic. In the first part of the thesis using a combined phylogenetic and structural biology approach we have identified two bacterial protein families of non-canonical fatty acid biosynthesis starter enzymes and trans-acting polyketide enoyl reductases (ER) as potential ancestors of core scaffolding regions in fFAS. The architectures of both protein families are revealed by representative crystal structures of the starter enzyme FabY and DfnA-ER. In both families, a striking structural conservation of insertions to scaffolding elements in fFAS is observed, despite marginal sequence identity. The combined phylogenetic and structural data provide first insights into the evolutionary origins of the complex multienzyme architecture of fFAS. In contrast structural and evolutionarily analysis revealed that animal FAS is related to polyketide synthase type I (PKS I), which is utilized by bacteria to synthesize a broad spectrum of secondary metabolites. Animal FAS is 6 an open X-shaped structure with catalytic domains not interrupted by the insertion of scaffolding elements but connected to each other via short not conserved linker sequences. Crystallographic data together with biochemical and electron microscopy (EM) analysis indicate that animal FAS displays an extraordinary degree of flexibility to ensure productive interactions between the active sites during the reaction cycle. Conformational changes most likely result from a combination of internal domain flexibility in the linker regions, which connects individual domains in the animal FAS. The second part of the thesis is thus dedicated to investigating how intra domain linking influences catalytic properties and conformational crosstalk between domains. This was achieved by generating more then 40 different constructs with various linker lenths. Combined structural and kinetic data from purified constructs helped us to better understand the emergent properties of the megasynthase system. A long-term goal is to use these insights for the construction of artificial multienzymes incorporating complete and complex molecular pathways