Quantitative MRCP and metrics of bile duct disease over time in patients with primary sclerosing cholangitis: A prospective study

BACKGROUND

Imaging markers of biliary disease in primary sclerosing cholangitis (PSC) have potential for use in clinical and trial disease monitoring. Herein, we evaluate how quantitative magnetic resonance cholangiopancreatography (MRCP) metrics change over time, as per the natural history of disease.

METHODS

Individuals with PSC were prospectively scanned using non-contrast MRCP. Quantitative metrics were calculated using MRCP+ post-processing software to assess duct diameters and dilated and strictured regions. Additionally, a hepatopancreatobiliary radiologist (blinded to clinical details, biochemistry and quantitative biliary metrics) reported each scan, including ductal disease assessment according to the modified Amsterdam Cholangiographic Score (MAS).

RESULTS

At baseline, 14 quantitative MRCP+ metrics were found to be significantly different in patients with PSC (N = 55) compared to those with primary biliary cholangitis (N = 55), autoimmune hepatitis (N = 57) and healthy controls (N = 18). In PSC specifically, baseline metrics quantifying the number of strictures and the number and length of bile ducts correlated with the MAS, transient elastography and serum ALP values (p < 0.01 for all correlations). Over a median 371-day follow-up (range: 364-462), 29 patients with PSC underwent repeat MRCP, of whom 15 exhibited quantitative changes in MRCP+ metrics. Compared to baseline, quantitative MRCP+ identified an increasing number of strictures over time (p < 0.05). Comparatively, no significant differences in biochemistry, elastography or the MAS were observed between timepoints. Quantitative MRCP+ metrics remained stable in non-PSC liver disease.

CONCLUSION

Quantitative MRCP+ identifies changes in ductal disease over time in PSC, despite stability in biochemistry, liver stiffness and radiologist-derived cholangiographic assessment (trial registration: ISRCTN39463479).

A flexible mixed-optimization with H∞ control for coupled twin rotor MIMO system based on the method of inequality (MOI)- An experimental study

This article introduces a cutting-edge H∞ model-based control method for uncertain Multi Input Multi Output (MIMO) systems, specifically focusing on UAVs, through a flexible mixed-optimization framework using the Method of Inequality (MOI). The proposed approach adaptively addresses crucial challenges such as unmodeled dynamics, noise interference, and parameter variations. Central to the design is a two-step controller development process. The first step involves Nonlinear Dynamic Inversion (NDI) and system decoupling for simplification, while the second step integrates H∞ control with MOI for optimal response tuning. This strategy is distinguished by its adaptability and focus on balancing robust stability and performance, effectively managing the intricate cross-coupling dynamics in UAV systems. The effectiveness of the proposed approach is validated through simulations conducted in MATLAB/Simulink environment. Results demonstrated the efficiency of the proposed robust control approach as evidenced by reduced steady-state error, diminished overshoot, and faster system response times, thus significantly outperforming traditional control methods.

Adequate versus deep response to ursodeoxycholic acid in primary biliary cholangitis: To what extent and under what conditions is normal alkaline phosphatase level associated with complication-free survival gain?

BACKGROUND AND AIMS

Normal alkaline phosphatase (ALP) levels in ursodeoxycholic acid (UDCA)-treated patients with primary biliary cholangitis (PBC) are associated with better long-term outcome. However, second-line therapies are currently recommended only when ALP levels remain above 1.5 times the upper limit of normal (×ULN) after 12-month UDCA. We assessed whether, in patients considered good responders to UDCA, normal ALP levels were associated with significant survival gains.

APPROACH AND RESULTS

We performed a retrospective cohort study of 1047 patients with PBC who attained an adequate response to UDCA according to Paris-2 criteria. Time to liver-related complications, liver transplantation, or death was assessed using adjusted restricted mean survival time (RMST) analysis. The overall incidence rate of events was 17.0 (95% CI: 13.7-21.1) per 1000 out of 4763.2 patient-years. On the whole population, normal serum ALP values (but not normal gamma-glutamyl transpeptidase (GGT), alanine aminotransferase (ALT), or aspartate aminotransferase (AST); or total bilirubin < 0.6 ×ULN) were associated with a significant absolute complication-free survival gain at 10 years (mean 7.6 months, 95% CI: 2.7 - 12.6 mo.; p = 0.003). In subgroup analysis, this association was significant in patients with a liver stiffness measurement ≥ 10 kPa and/or age ≤ 62 years, with a 10-year absolute complication-free survival gain of 52.8 months (95% CI: 45.7-59.9, p < 0.001) when these 2 conditions were met.

CONCLUSIONS

PBC patients with an adequate response to UDCA and persistent ALP elevation between 1.1 and 1.5 ×ULN, particularly those with advanced fibrosis and/or who are sufficiently young, remain at risk of poor outcome. Further therapeutic efforts should be considered for these patients.

Identification of a pH-Responsive Peptide-Paclitaxel Conjugate as a Novel Drug with Improved Therapeutic Potential

A highly sensitive, nontoxic, hydrophilic cell-penetrating peptide (CPP = c[RGDKLAK]) was selected for the construction of an effective peptide-drug conjugate (PDC). A hydrophobic drug paclitaxel (PTX) was successfully conjugated with CPP via ester linkage with succinic acid (SA) as a pH-cleavable linker moiety. The characterization techniques employed in this study indicate the >95% purity of the resulting PDC (CPP-SA-PTX). The in vitro studies show that our proposed PDC exhibits enhanced stability (∼90%) and cytotoxicity (EC₅₀ = 8.32 ± 0.09 nM). Besides the excellent solubility of PDC in water, the PTX effect on positive β-tubulin-III indicates that the drug releases retained pharmacological properties. Additionally, in vivo, therapeutic-dose treatment reveals the prominent tumor-growth inhibitory effects (2.82-3.24-fold) of PDC in tumor mice models. Subsequently, these observations confirmed that our novel-designed PDC (CPP-SA-PTX) adduct may serve as a promising therapeutic agent to treat glioblastoma.

Guidance document: risk assessment of patients with cirrhosis prior to elective non-hepatic surgery

As a result of the increasing incidence of cirrhosis in the UK, more patients with chronic liver disease are being considered for elective non-hepatic surgery. A historical reluctance to offer surgery to such patients stems from general perceptions of poor postoperative outcomes. While this is true for those with decompensated cirrhosis, selected patients with compensated early-stage cirrhosis can have good outcomes after careful risk assessment. Well-recognised risks include those of general anaesthesia, bleeding, infections, impaired wound healing, acute kidney injury and cardiovascular compromise. Intra-abdominal or cardiothoracic surgery are particularly high-risk interventions. Clinical assessment supplemented by blood tests, imaging, liver stiffness measurement, endoscopy and assessment of portal pressure (derived from the hepatic venous pressure gradient) can facilitate risk stratification. Traditional prognostic scoring systems including the Child-Turcotte-Pugh and Model for End-stage Liver Disease are helpful but may overestimate surgical risk. Specific prognostic scores like Mayo Risk Score, VOCAL-Penn and ADOPT-LC can add precision to risk assessment. Measures to mitigate risk include careful management of varices, nutritional optimisation and where possible addressing any ongoing aetiological drivers such as alcohol consumption. The role of portal decompression such as transjugular intrahepatic portosystemic shunting can be considered in selected high-risk patients, but further prospective study of this approach is required. It is of paramount importance that patients are discussed in a multidisciplinary forum, and that patients are carefully counselled about potential risks and benefits.

Cirrhosis and non-hepatic surgery in 2023 - a precision medicine approach

INTRODUCTION

Patients with liver disease and portal hypertension frequently require surgery carrying high morbidity and mortality. Accurately estimating surgical risk remains challenging despite improved medical and surgical management.

AREAS COVERED

This review aims to outline a comprehensive approach to preoperative assessment, appraise methods used to predict surgical risk, and provide an up-to-date overview of outcomes for patients with cirrhosis undergoing non-hepatic surgery.

EXPERT OPINION

Robust preoperative, individually tailored, and precise risk assessment can reduce peri- and postoperative complications in patients with cirrhosis. Established prognostic scores aid stratification, providing an estimation of postoperative mortality, albeit with limitations. VOCAL-Penn Risk Score may provide greater precision than established liver severity scores. Amelioration of portal hypertension in advance of surgery may be considered, with prospective data demonstrating hepatic venous pressure gradient as a promising surrogate marker of postoperative outcomes. Morbidity and mortality vary between types of surgery with further studies required in patients with more advanced liver disease. Patient-specific considerations and practicing precision medicine may allow for improved postoperative outcomes.

UK national trainee survey of hepatology training, research and the future workforce

Objective

The increasing prevalence of liver disease in the UK means there is a pressing need to expand the hepatology workforce. This survey aims to evaluate current hepatology training provision, and trainee attitudes towards future careers in hepatology.

Method

An electronic survey was distributed to higher specialty gastroenterology and hepatology trainees in the UK between March and May 2022.

Results

138 trainees completed the survey covering all training grades and regions of the UK. 73.7% reported receiving adequate hepatology training currently, with 55.6% intending to become future hepatologists. Trainee preference for future hepatology consultant posts in specialist liver centres were almost threefold higher compared with district general hospitals (60.9% vs 22.6%). All trainees, irrespective of training grade reported high confidence in managing decompensated cirrhosis in both inpatient and outpatient settings. Senior trainees (grade ST6 and higher), without advanced training programme (ATP) experience reported significantly lower confidence in managing viral hepatitis, hepatocellular carcinoma and post-transplant patients compared with equivalent trainees with ATP experience. For junior trainees (IMT3-ST5), remaining in their current deanery was the most important factor when considering future hepatology training application.

Conclusions

There is a significant need to deliver widely available training on the management of complex liver disease to improve non-ATP trainee confidence. Innovative job planning strategies are required to encourage trainees to pursue careers outside of specialist liver centres. Expansion of hepatology training networks with wider geographical coverage are needed to address the growing need for more hepatologists around the UK.

Liver stiffness measurement by vibration-controlled transient elastography improves outcome prediction in primary biliary cholangitis

BACKGROUND & AIMS

Liver stiffness measurement (LSM) by vibration-controlled transient elastography (VCTE) has been shown to predict outcomes of patients with primary biliary cholangitis (PBC) in small-size studies. We aimed to validate the prognostic value of LSM in a large cohort study.

METHODS

We performed an international, multicentre, retrospective follow-up study of 3,985 patients with PBC seen at 23 centres in 12 countries. Eligibility criteria included at least 1 reliable LSM by VCTE and a follow-up ≥ 1 year. Independent derivation (n = 2,740) and validation (n = 568) cohorts were built. The primary endpoint was time to poor clinical outcomes defined as liver-related complications, liver transplantation, or death. Hazard ratios (HRs) with CIs were determined using a time-dependent multivariable Cox regression analysis.

RESULTS

LSM was independently associated with poor clinical outcomes in the derivation (5,324 LSMs, mean follow-up 5.0 ± 3.1 years) and validation (1,470 LSMs, mean follow-up 5.0 ± 2.8 years) cohorts: adjusted HRs (95% CI) per additional kPa were 1.040 (1.026-1.054) and 1.042 (1.029-1.056), respectively (p <0.0001 for both). Adjusted C-statistics (95% CI) at baseline were 0.83 (0.79-0.87) and 0.92 (0.89-0.95), respectively. Between 5 and 30 kPa, the log-HR increased as a monotonic function of LSM. The predictive value of LSM was stable in time. LSM improved the prognostic ability of biochemical response criteria, fibrosis scores, and prognostic scores. The 8 kPa and 15 kPa cut-offs optimally separated low-, medium-, and high-risk groups. Forty percent of patients were at medium to high risk according to LSM.

CONCLUSIONS

LSM by VCTE is a major, independent, validated predictor of PBC outcome. Its value as a surrogate endpoint for clinical benefit in PBC should be considered.

LAY SUMMARY

Primary biliary cholangitis (PBC) is a chronic autoimmune disease, wherein the body's immune system mistakenly attacks the bile ducts. PBC progresses gradually, so surrogate markers (markers that predict clinically relevant outcomes like the need for a transplant or death long before the event occurs) are often needed to expedite the drug development and approval process. Herein, we show that liver stiffness measurement is a strong predictor of clinical outcomes and could be a useful surrogate endpoint in PBC trials.

Real-time robust generalized dynamic inversion based optimization control for coupled twin rotor MIMO system

This work is used to design a novel robust optimization control law augmented with Robust Generalized Dynamic Inversion (RGDI) for continuous varying perturbations in the Twin Rotor MIMO System (TRMS). The perturbations like coupling effect, un-known states, gyroscopic disturbance torque, parametric uncertainties and parametric disturbances are considered as unwanted signal which should be optimized by an efficient controller. The variable structured systems like the TRMS (prototype) have great focus due to its high computational cost with a higher order non-linear behavior. The RGDI based controller designed to remove nonlinear dynamics as well as to avoid singularity issue with the augmentation of stability based mathematical operations (lyapunov stability analysis, controllability and observability matrices ) in the presence of considered perturbations during implementation. In this paper, we develop estimation of state deviation calculation between control angles and desired angles known as Euclidean error norm. The next step was to design RGDI based controller [Sliding Mode Control (SMC) and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${H_\infty }$$\end{document}H∞ optimization] to minimize considered perturbations as well as the computational cost. The sharp (rapid) chattering phenomena in RGDI based SMC reduce the actuators performance that goes towards the failure of actuators. While the RGDI based \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${H_\infty }$$\end{document}H∞ optimization overcome the computational cost and minimizes \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${H_\infty }$$\end{document}H∞ norm that’s guaranteeing the robust stability as well as robust performance. The robustness of the optimization control technique validated by taking its worst case via MATLAB-Simulation. A real-time implementation applied to evaluate the worth of novel dynamic approach.

UK-Wide Multicenter Evaluation of Second-line Therapies in Primary Biliary Cholangitis

BACKGROUND & AIMS

Thirty-to-forty percent of patients with primary biliary cholangitis inadequately respond to ursodeoxycholic acid. Our aim was to assemble national, real-world data on the effectiveness of obeticholic acid (OCA) as a second-line treatment, alongside non-licensed therapy with fibric acid derivatives (bezafibrate or fenofibrate).

METHODS

This was a nationwide observational cohort study conducted from August 2017 until June 2021.

RESULTS

We accrued data from 457 patients; 349 treated with OCA and 108 with fibric acid derivatives. At baseline/pre-treatment, individuals in the OCA group manifest higher risk features compared with those taking fibric acid derivatives, evidenced by more elevated alkaline phosphatase values, and a larger proportion of individuals with cirrhosis, abnormal bilirubin, prior non-response to ursodeoxycholic acid, and elastography readings >9.6kPa (P < .05 for all). Overall, 259 patients (OCA) and 80 patients (fibric acid derivatives) completed 12 months of second-line therapy, yielding a dropout rate of 25.7% and 25.9%, respectively. At 12 months, the magnitude of alkaline phosphatase reduction was 29.5% and 56.7% in OCA and fibric acid groups (P < .001). Conversely, 55.9% and 36.4% of patients normalized serum alanine transaminase and bilirubin in the OCA group (P < .001). The proportion with normal alanine transaminase or bilirubin values in the fibric acid group was no different at 12 months compared with baseline. Twelve-month biochemical response rates were 70.6% with OCA and 80% under fibric acid treatment (P = .121). Response rates between treatment groups were no different on propensity-score matching or on sub-analysis of high-risk groups defined at baseline.

CONCLUSION

Across the population of patients with primary biliary cholangitis in the United Kingdom, rates of biochemical response and drug discontinuation appear similar under fibric acid and OCA treatment.

Acute-on-chronic liver failure (ACLF) in 2022: have novel treatment paradigms already arrived?

INTRODUCTION

Acute-on-chronic failure (ACLF) is a recognized syndrome in patients with chronic liver disease and is characterized by acute decompensation, organ failure(s), and a high short-term mortality. ACLF is often triggered by ongoing alcohol consumption, gastrointestinal bleeding and/or infections, and is pathophysiologically characterized by uncontrolled systemic inflammation coupled with paradoxical immunoparesis. Patients with ACLF require prompt and early recognition. Management requires extensive utilization of clinical resources often including escalation to intensive care.

AREAS COVERED

Currently, there are no specific targeted treatments for established ACLF, and management revolves around treating underlying precipitants and providing organ support. In this article, we review the epidemiology and pathophysiology of ACLF and summarize recent advances in management strategies of this syndrome, focusing specifically on novel emerging therapies.

EXPERT COMMENTARY

ACLF is a challenging condition with rapid clinical course, high short-term mortality and varying clinical phenotypes. Management of ACLF is broadly focused on supportive care often in an intensive care setting with liver transplantation proving to be an increasingly relevant and effective rescue therapy. This disease has clear pathogenesis and epidemiological burden, thus distinguishing it from decompensated cirrhosis; there is clear clinical need for the development of specific and nuanced therapies to treat this condition.

Emerging drugs for the treatment of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a rare immune-mediated cholestatic disease for which no medical therapy has been shown to slow disease progression. Consequently, liver transplantation is the only lifesaving intervention for patients, and despite being a rare disease, PSC is the lead indication for transplantation across several European countries. The vast majority of patients (>70%) also develop inflammatory bowel disease (IBD) at some point in their lifetime, which imparts added lifetime risks of hepatobiliary malignancy and colorectal cancer. The rare disease nature, variable and often slow rates of disease progression (years rather than months), and lack of robust surrogate biomarkers for early stage yet high risk disease, represent critical challenges in trial design that have long precluded the development of effective medical treatment. However, the horizon for new treatments is encouraging, given innovative clinical trial programmes led by industry, alongside several investigator-initiated studies. Herein, we outline the current platform of interventional trials in PSC, before discussing emerging areas of therapeutic interest.

Synthesis, characterization, anti-microbial and cytotoxic applications of zinc(II) complexes

ABSTRACT. In the present research, three zinc(II) complexes were synthesized using 3-(3-fluorophenyl)-2-methylacrylic acid (HL), 1,10-phenanthroline and 2,2'-pyridine as ligands. The composition, structural confirmation, coordination way of ligand and assignment of geometry to the complexes were made by different analytical tools like elemental analysis, FTIR and 1H-NMR. The ligand 3-(3-fluorophenyl)-2-methylacrylate appeared to coordinate the metal (Zn) atom via COO- moiety in all of the complexes (1-3) while 1,10-phenanthroline and 2,2'-pyridine co-ordinated to Zn(II) atom through N-donor sites in complexes 2 and 3, respectively. The complex 1 showed four while 2 and 3 showed six co-ordinated geometry. The synthesized complexes were evaluated for antimicrobial and cytotoxic activities. The obtained results showed that complexes are active against microbial agents and exhibited significant cytotoxicity.                     KEY WORDS: Co-coordination, Geometry, Zinc(II) complexes, Biological activity   Bull. Chem. Soc. Ethiop. 2021, 35(2), 287-299. DOI: https://dx.doi.org/10.4314/bcse.v35i2.6

Current Application of Chemometrics Analysis in Authentication of Natural Products: A Review

BACKGROUND

The efficiency of herbal medicinal products depends on the quantity of active ingredients in them, which can differ considerably in contents. Hence, a very critical concern is the quality control of herbal medicines.

OBJECTIVE

To provide a succinct review of recent chemometrics applications in solving the uncertainty of the authentication of herbal medicine over the last two decades.

METHODOLOGY

Studies involving chemometrics applications in conjunction with various analytical methods have been categorized according to the type of research used in the quality evaluation of different samples, including chromatographic (HPLC, GC-MS) and spectroscopic analysis (UV-Vis, FTIR, NMR, and MS).

RESULTS

This review consists of over 90 studies illustrating the relevance of chemometrics methods in the discrimination based on the key bioactive components and phytochemical diversity of several herbs from closely related species. Besides, the distinction between varieties and hybrids was accomplished through quantitative analysis techniques, in addition to the prediction of the active components.

CONCLUSION

Methods of chemometrics have provided an important and potent tool for the quality control and authentication of various herbs.

ATR-FTIR Spectroscopy, HPLC Chromatography, and Multivariate Analysis for Controlling Bee Pollen Quality in Some Algerian Regions

Bee pollen collected by honeybees (Apis mellifera) is one of the bee products, and it is as valuable as honey, propolis, royal jelly, or beebread. Its quality varies according to its geographic location or plant sources. This study aimed to apply rapid, simple, and accurate analytical methods such as attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and high-performance liquid chromatography (HPLC) along with chemometrics analysis to construct a model aimed at discriminating between different pollen samples. In total, 33 samples were collected and analyzed using principal component analysis (PCA), hierarchical clustering analysis (HCA), and partial least squares regression (PLS) to assess the differences and similarities between them. The PCA score plot based on both HPLC and ATR-FTIR revealed the same discriminatory pattern, and the samples were divided into four major classes depending on their total content of polyphenols. The results revealed that spectral data obtained from ATR-FTIR acquired in the region (4000-500 cm^-1) were further subjected to a standard normal variable (SNV) method that removes scattering effects from spectra. However, PCA, HCA, and PLS showed that the best PLS model was obtained with a regression coefficient (R ²) of 0.9001, root-mean-square estimation error (RMSEE) of 0.0304, and root-mean-squared error cross-validation (RMSEcv) of 0.036. Discrimination between the three species has also been possible by combining the pre-processed ATR-FTIR spectra with PCA and PLS. Additionally, the HPLC chromatograms after pre-treatment (SNV) were subjected to unsupervised analysis (PCA-HCA) and supervised analysis (PLS). The PLS model confers good results by factors (R ² = 0.98, RMSEE = 8.22, and RMSEcv = 27.86). Prospects for devising bee pollen quality assessment methods include utilizing ATR-FTIR and HPLC in combination with multivariate methods for rapid authentication of the geographic location or plant sources of bee pollen.

Facile Synthesis of Sprayed CNTs Layer-Embedded Stretchable Sensors with Controllable Sensitivity

Flexible electronic devices have gained significant interest due to their different potential applications. Herein, we report highly flexible, stretchable, and sensitive sensors made of sprayed CNT layer, sandwiched between two polymer layers. A facile fabrication process was employed in which the CNT solution was directly sprayed onto a patterned bottom polymer layer, above which a second polymer layer was casted to get a sandwiched composite structure. Varying amounts of CNT solution (i.e., 10, 25, 40, 70, and 100 mL) were sprayed to get conductive CNT layers of different thicknesses/densities. The physical characteristics of the conductive CNT layers were studied through SEM and optical images. The starting electrical resistance values (without strain) as well as the changes in electrical resistance against human body motions were monitored. The synthesized samples exhibited good response against finger and wrist bending. The conductivity of the samples increased with increase of CNT solution volume while the sensitivity followed the inverse relation, suggesting that the sensors with controlled sensitivity could be fabricated for targeted strain ranges using the proposed method.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Evaluation of Biting Force of New Design of Extracoronal Castable Precision Attachment versus Conventional Partial Denture for Treatment of Unilateral Mandibular Distal Extension Area: A Randomized Controlled Trial

PURPOSE: The aim of this study was to evaluate biting force of patients with unilateral mandibular distal extension area treated with two different designs of the removable partial denture (RPD), conventional RPD, and new design of extracoronal castable precision attachment (OT Unilateral attachment). MATERIALS AND METHODS: This study was conducted on 16 patients with unilateral mandibular distal extension area with the second premolar is the last abutment teeth. The patients were divided into two equal groups, Group I received conventional RPD, which provides cross arch stabilization and a double Aker clasp was fabricated. Group II received new design of extracoronal castable precision attachment (OT Unilateral attachment). Evaluation of biting force by loadstar sensor, patients of both groups were evaluated at the time of prosthesis insertion, 3, 6, and 1 year later. Statistical analysis performing one-way analysis of variance followed by Tukey’s post hoc test to compare between all follow-up periods within each group, comparison between two groups regarding each follow-up period was performed by independent t-test. RESULTS: Both treatments yielded better after-treatment summary when compared with the baseline; however, better results were obtained and showed a statistically significant increase in Group II (OT unilateral design), especially after 3, 6 months, and 1 year later. CONCLUSION: From the results of this study, it was concluded that: It is preferable to use the new design of extracoronal castable precision attachment (OT unilateral) being simpler, more comfortable to the patients and give high masticatory efficiency in the form of biting force than conventional RPD.  

Tunnelled peritoneal drainage catheter placement for the palliative management of refractory ascites in patients with liver cirrhosis

OBJECTIVE

Refractory ascites is an established indication for liver transplantation. While transplantation is regarded as the definitive therapy for this condition, many patients are unsuitable due to comorbidity or frailty. Alternatives such as transjugular intrahepatic portosystemic shunt (TIPSS) and large-volume paracentesis can lead to complications, including encephalopathy, circulatory and renal dysfunction, and protein-calorie deficiency that may accelerate sarcopenia. Cost and complication rates limit therapies such as alfapump. While there are data to support the use of indwelling catheters in the management of patients with malignant ascites, there is limited evidence to support their routine use in the context of end-stage liver cirrhosis. Here we describe our centres' experience using indwelling tunnelled ascitic drains over a 6-year period.

METHODS

A retrospective review of data (January 2012-May 2018) was undertaken for all patients with refractory ascites who underwent a tunnelled ascitic drain. Demographics, disease aetiology, procedure data and follow-up data were obtained through interrogation of electronic records and reports.

RESULTS

Twenty-five drains were placed. All procedures were technically successful with no immediate complications. Six patients were readmitted following their index admission with abdominal pain and suspected infected ascites (although only two had a positive ascitic fluid culture). There were three cases of abdominal wall cellulitis and three of leakage around the tunnel site; all managed conservatively.

CONCLUSION

Indwelling drains appear an effective strategy for palliative management of select patients with liver cirrhosis complicated by refractory ascites who are not amenable to undergo TIPSS or transplantation. While complications can occur, these are most usually minor and can be managed on an outpatient basis.

Exploration of a New Source of Sustainable Nanomaterial from the Koh-e-Suleiman Mountain Range of Pakistan for Industrial Applications

The present study aimed to explore a new source of montmorillonite and to develop an extraction and purification protocol for its isolation from raw clay samples acquired from the Koh-e-Suleiman mountain range in Pakistan. The process involved the collection of raw clay from the source, identification and quantification of montmorillonite. Granulometric extraction and purification protocols increased the montmorillonite content from 21.8-25.1% in the raw clay to 90.1-93.9% after small-scale extraction and 85.33-89.33% on a larger scale. A techno-economic analysis highlighted the practicality and economic benefits of large-scale extraction for industrial applications. This study highlights the existence of a substantial new source of this valuable clay which is currently used across multiple industries including construction, pottery making, pharmaceuticals, cosmetics and engineering. It is intuitively expected that the large-scale extraction of the material will improve the economic condition of the region by providing employment opportunities to locals and may be a valuable resource for export.

Correction to: Determination of the Genetic and Synergistic Suppression of a Methoxyfenozide-Resistant Strain of the House Fly Musca domestica L. (Diptera: Muscidae)

Due to an unfortunate turn of events, the surname of the last author appeared incorrectly in the original publication as the name should have read Binyameen.

Determination of the Genetic and Synergistic Suppression of a Methoxyfenozide-Resistant Strain of the House Fly Musca domestica L. (Diptera: Muscidae)

Musca domestica Linnaeus (house fly, Diptera: Muscidae) is a major veterinary and medical important pest all over the world. These flies have ability to develop resistance to insecticides. The present trial was performed to discover the inheritance mode (autosomal, dominance, number of genes involved) and preliminary mechanism of methoxyfenozide resistance in order to provide basic information necessary to develop resistance management strategy for this pest. A strain of M. domestica (MXY-SEL) was exposed to methoxyfenozide for 44 generations which developed a 5253.90-fold level of resistance to methoxyfenozide. The overlapping fiducial limits of LC₅₀ values of the reciprocal crosses, F₁ (MXY-SEL ♂ × Susceptible ♀) and F₁^† (MXY-SEL ♀ × Susceptible ♂), suggest that inheritance of methoxyfenozide resistance was an autosomal and likely completely dominant trait (D_LC = 0.93 and 0.94 for F₁ and F₁^†, respectively). Backcrosses of the F₁ with the parental MXY-SEL or Susceptible population predict a polygenic mode of inheritance. Piperonyl butoxide significantly altered the LC₅₀ values, suggesting enhanced detoxification by cytochrome P450-dependent monooxygenases is a major mechanism of resistance to methoxyfenozide in the MXY-SEL strain. The estimated realized heritability was 0.07 for methoxyfenozide. These results would be helpful for the better management of M. domestica.

The ASOS Surgical Risk Calculator: development and validation of a tool for identifying African surgical patients at risk of severe postoperative complications

BACKGROUND

The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. Existing risk assessment tools are not valid for use in this population because the pattern of risk for poor outcomes differs from high-income countries. The objective of this study was to derive and validate a simple, preoperative risk stratification tool to identify African surgical patients at risk for in-hospital postoperative mortality and severe complications.

METHODS

ASOS was a 7-day prospective cohort study of adult patients undergoing surgery in Africa. The ASOS Surgical Risk Calculator was constructed with a multivariable logistic regression model for the outcome of in-hospital mortality and severe postoperative complications. The following preoperative risk factors were entered into the model; age, sex, smoking status, ASA physical status, preoperative chronic comorbid conditions, indication for surgery, urgency, severity, and type of surgery.

RESULTS

The model was derived from 8799 patients from 168 African hospitals. The composite outcome of severe postoperative complications and death occurred in 423/8799 (4.8%) patients. The ASOS Surgical Risk Calculator includes the following risk factors: age, ASA physical status, indication for surgery, urgency, severity, and type of surgery. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.805 and good calibration with c-statistic corrected for optimism of 0.784.

CONCLUSIONS

This simple preoperative risk calculator could be used to identify high-risk surgical patients in African hospitals and facilitate increased postoperative surveillance.

CLINICAL TRIAL REGISTRATION

NCT03044899.

Synthesis of geopolymer-supported zeolites via robust one-step method and their adsorption potential

The present study proposes a robust one-step hydrothermal treatment method for synthesis of high strength geopolymer-supported zeolites utilizing industrial by-products (fly ash and blast furnace slag), which can be potentially used as bulk-type solid adsorbents. The results revealed that the geopolymer-supported zeolites, possessing distinct strengths, zeolite phases (Na-P1, Na-chabazite, and analcime) and pore features depending on the mix design and synthesis conditions, can be easily synthesized employing the proposed one-step method. The geopolymer-supported zeolites exhibited the characteristics of mesoporous materials which are typically desired for commercial adsorbents. The maximum adsorption capacity for Pb²⁺ was found to be about 37.9 mg/g which is relatively higher than the other bulk-type adsorbents reported for Pb²⁺ to date. Since industrial by-products are used for synthesis of these materials, it will help in reducing the environmental hazards associated with the permanent disposal of such by-products, with an added advantage that these bulk-type solid adsorbents can be easily retrieved after use unlike granular adsorbents.

Polymeric Based Therapeutic Delivery Systems Prepared Using Electrohydrodynamic Processes

The development of therapeutic dosage (e.g. pharmaceutical) systems is an ongoing process which, in recent times has incorporated several emerging disciplines and themes at timely intervals. While the concepts surrounding dosage forms have developed and evolved, many polymeric excipients remain as the preferred choice of materials over existing counterparts, serving functions as matrix materials, coatings and providing other specific functional properties (e.g. adhesion, controlled release and mechanical properties). There have been, however, developments in the deployment of synthetic polymeric materials (e.g. polycaprolactone, poly lactic co-glycolic acid) when compared to naturally occurring materials (e.g. lactose, gelatin). Advances in pharmaceutical process technologies have also provided novel engineering platforms to develop a host of exciting structure based materials ranging from the nanometer to the macro scales. Some of these structure enabling technologies include spray drying, super critical processing, microfluidics and even wet chemical methods. More recently electrohydrodynamic (EHDA) engineering methods have emerged as robust technologies offering potential to fabricate a plethora of generic structures (e.g. particles, fibres, bubbles and pre-determined patterns) on a broad scale range. This review focuses on key developments using various EHDA technologies for the pharmaceutical and biomaterial remits when selecting synthetic and/or naturally occurring polymers as pharmaceutical (and therapeutic) excipients. In addition, the underlying EHDA process principles are discussed along with key parameters and variables (both materials and engineering). EHDA technologies are operational at ambient conditions and recent developments have also demonstrated their viability for large scale production. These are promising technologies which have potential in established (e.g. films, dressings and microparticles) and emerging scientific themes (e.g. nanomedicines and tissue engineering).