A comprehensive review on current technologies for removal of endocrine disrupting chemicals from wastewaters

In the recent years, endocrine disrupting compounds (EDCs) has received increasing attention due to their significant toxic effects on human beings and wildlife by affecting their endocrine systems. As an important group of emerging pollutant, EDCs have been detected in various aquatic environments, including surface waters, groundwater, wastewater, runoff, and landfill leachates. Their removal from water resources has also been an emerging concern considering growing population as well as reducing access to fresh water resources. EDC removal from wastewaters is highly dependent on physicochemical properties of the given EDCs present in each wastewater types as well as various aquatic environments. Due to chemical, physical and physicochemical diversities in these parameters, variety of technologies consisting of physical, biological, electrochemical, and chemical processes have been developed for their removal. This review highlights that the effectiveness of EDC removal is highly dependent of selecting the appropriate technology; which decision is made upon a full wastewater chemical characterization. This review aims to provide a comprehensive perspective about all the current technologies used for EDCs removal from various aquatic matrices along with rising challenges such as the antimicrobial resistance gene transfer during EDC treatment.

A227 THE EFFECTIVENESS OF PEG 3350 COMPARED TO LACTULOSE FOR THE TREATMENT OF ACUTE HEPATIC ENCEPHALOPATHY IN ADULT CIRRHOTIC PATIENTS: A SYSTEMATIC REVIEW AND META-ANALYSIS

Background

Cirrhosis is the leading cause of liver-related death globally. Hepatic encephalopathy (HE) leads to significant morbidity and mortality. Lactulose is the current gold standard treatment for HE; it eliminates nitrogenous waste from the gut. Polyethylene glycol 3350–electrolyte solution (PEG) is a safe, common and effective purgative with recent studies suggesting its efficacy resulting in faster resolution of HE and shorter hospital length of stay.

Aims

To assess the efficacy and safety of PEG 3350 compared to lactulose in adult cirrhotic patients 18 years of age and older with overt hepatic encephalopathy on patient important outcomes including: improvement of hepatic encephalopathy, hospital length of stay and mortality.

Methods

We reviewed databases MEDLINE, EMBASE, OVID, CINAHL, Cochrane Database, PubMed, Trip database, the grey literature, and clinicaltrials.gov from inception to December 2020: PROSPERO CRD42021257641. Search strategy was developed in conjunction with medical librarian. Randomized controlled trials (RCTs), either published or non-published, were included in the review. Continuous data was analyzed using mean difference with random-effects model. Dichotomous data was analyzed using the Mantel-Haenszel method using random-effects model. Statistical effect-size heterogeneity was assessed using Chi2 test and quantifying the relative proportion of variation using I2 statistic. The overall certainty of evidence will be assessed using the Grading of Recommendations, Assessment, Development and Evaluations system (GRADE).

Results

From the 68 studies, 16 were assessed for full text review from which 5 studies were included in the meta-analysis representing a total of 351 patients. The primary outcome of mean change in Hepatic Encephalopathy Scoring Algorithm (HESA) at 24-hours from baseline demonstrated an improvement in the PEG group compared to lactulose group [Mean difference (MD)= 0.60, 95% CI (0.20, 1.01)]. In comparison to lactulose, PEG also demonstrated a shorter hospital length of stay [MD = -1.00, 95% CI (-1.99, -0.01)], shorter time to HE resolution [MD= -1.49, 95% CI (-1.81, -1.16)] and showed a mortality benefit [RR=0.35, 95% CI (0.13 to 0.92)]. There was no significant difference between change in ammonia levels at 24 hours [MD= -25.80, 95% CI (-95.39, 43.78)].

Conclusions

PEG leads to a faster improvement and resolution of HE when compared to the current standard of care, lactulose.

Funding Agencies

None

A146 MANAGEMENT OF ANTITHROMBOTIC THERAPY AFTER GASTROINTESTINAL BLEEDING: A MIXED METHODS STUDY OF HEALTHCARE PROVIDERS

Background

Oral anticoagulants (OAC) are permanently discontinued in up to 50% of patients after gastrointestinal (GI) bleeding despite ongoing thrombotic risk and evidence of benefit to restarting. The reasons for permanent discontinuation of OAC are unclear, but likely include concerns about re-bleeding and a lack of high-quality evidence. There are no studies evaluating healthcare provider values and preferences following OAC-related GI bleeding and their influence on decision-making about whether and when to resume OACs.

Aims

We aimed to (i) identify key factors (attributes) that influence healthcare provider decision-making regarding resumption of OAC after GI bleeding, (ii) determine the relative importance of these attributes, and (iii) to identify preference groups.

Methods

We conducted focus group discussions (FGD) with healthcare providers involved in the care of patients with OAC-related GI bleeding. Participants ranked the relative importance of the attributes identified during the FGD through a dot voting exercise. Transcripts were reviewed and themes (attributes) were identified. Results of the FGD informed a discrete choice experiments survey developed and analyzed using the Sawtooth software platform (Sawtooth Software, USA). The survey was pilot tested and modified by iterative feedback. A sample choice task is shown in Image 1. Hierarchical Bayes analysis was used to estimate preference coefficients (utilities) for each attribute. Latent class analysis was used to identify preference groups.

Results

There were 4 FGD involving 29 participants. The most important attributes identified and included in the survey were thrombosis risk, indication for OAC, index bleed severity, re-bleeding risk, and patient characteristics. There were 130 survey respondents practicing in hematology (n=68), internal medicine (n=30), gastroenterology (n=7), cardiology (n=4), family medicine (n=3), and others (n=18). The mean age was 45 years (±11) and 51% were male. Thrombosis risk and re-bleeding risk equally had the highest utility followed by index bleed severity, patient characteristics, and indication for OAC. Two preference groups were identified. The dominant preference group (78% of respondents) placed the highest utility on thrombosis risk and re-bleeding risk, while a minority (22% of respondents) placed the highest utility on index bleed severity.

Conclusions

Thrombosis risk and re-bleeding risk are equally the most important factors influencing OAC resumption following OAC-related GI bleeding. The severity of the index bleed is the most important factor in decision-making for a minority segment of healthcare providers. Further research on the dose, type and timing of OAC resumption is needed to determine the optimal balance between thrombosis and re-bleeding.

Funding Agencies

Heart and Stroke Foundation

A quantitative analysis of the supercontraction-induced molecular disorientation of major ampullate spider silk

Spider silks exhibit remarkable properties, among which the so-called supercontraction, a physical phenomenon by which fibers undergo a longitudinal shrinkage and a radial swelling when exposed to water. The process is marked by a significant decrease in chain orientation resulting from plasticisation of the amorphous phase. Despite several studies that determined the Hermans orientation function, more quantitative data are required to be able to describe theoretically the macroscopic water-induced shrinkage from molecular reorganization. Here, we have examined the supercontraction of the major ampullate silk single fibers of Nephila clavipes (Nc) and Araneus diadematus (Ad) using polarized Raman spectromicroscopy. We determined the order parameters, the orientation distribution and the secondary structure content. Our data suggest that supercontraction induces a slight increase in β-sheet content, consistently with previous works. The β-sheet orientation is slightly affected by supercontraction compared to that of the amorphous phase, which becomes almost isotropic with shrinkage. Despite an initially lower orientation level, the Ad fiber shows a larger orientation decrease than Nc, consistently with its higher shrinkage amplitude. Although they share similar trends, absolute values of the orientation parameters from this work differ from those found in the literature. We took advantage of having determined the distribution of orientation to estimate the amplitude of shrinkage from changes in macromolecular size resulting from molecular disorientation. Our calculations show that more realistic models are needed to correlate molecular reorientation/refolding to macroscopic shrinkage. This work also underlines that more accurate data relative to molecular orientation are necessary.

Major Ampullate Spider Silk with Indistinguishable Spidroin Dope Conformations Leads to Different Fiber Molecular Structures

To plentifully benefit from its properties (mechanical, optical, biological) and its potential to manufacture green materials, the structure of spider silk has to be known accurately. To this aim, the major ampullate (MA) silk of Araneus diadematus (AD) and Nephila clavipes (NC) has been compared quantitatively in the liquid and fiber states using Raman spectromicroscopy. The data show that the spidroin conformations of the two dopes are indistinguishable despite their specific amino acid composition. This result suggests that GlyGlyX and GlyProGlyXX amino acid motifs (X = Leu, Glu, Tyr, Ser, etc.) are conformationally equivalent due to the chain flexibility in the aqueous environment. Species-related sequence specificity is expressed more extensively in the fiber: the β-sheet content is lower and width of the orientation distribution of the carbonyl groups is broader for AD (29% and 58°, respectively) as compared to NC (37% and 51°, respectively). β-Sheet content values are close to the proportion of polyalanine segments, suggesting that β-sheet formation is mainly dictated by the spidroin sequence. The extent of molecular alignment seems to be related to the presence of proline (Pro) that may decrease conformational flexibility and inhibit chain extension and alignment upon drawing. It appears that besides the presence of Pro, secondary structure and molecular orientation contribute to the different mechanical properties of MA threads.

Resident reflections on end-of-life education: a mixed-methods study of the 3 Wishes Project

OBJECTIVE

The objectives of this study were to describe residents' experiences with end-of-life (EOL) education during a rotation in the intensive care unit (ICU), and to understand the possible influence of the 3 Wishes Project.

DESIGN

We enrolled dying patients, their families and 1-3 of their clinicians in the 3 Wishes Project, eliciting and honouring a set of 3 wishes to bring peace to the final days of a critically ill patient's life, and ease the grieving process for families. We conducted semistructured interviews with 33 residents who had cared for 50 dying patients to understand their experiences with the project. Interviews were recorded, transcribed verbatim, then analysed using a qualitative descriptive approach.

SETTING

21-bed medical surgical ICU in a tertiary care, university-affiliated hospital.

RESULTS

33 residents participated from internal medicine (24, 72.7%), anaesthesia (8, 24.2%) and laboratory medicine (1, 3.0%) programmes in postgraduate years 1-3. 3 categories and associated themes emerged. (1) EOL care is a challenging component of training in that (a) death in the ICU can invoke helplessness, (b) EOL education is inadequate, (c) personal connections with dying patients is difficult in the ICU and (d) EOL skills are valued by residents. (2) The project reframes the dying process for residents by (a) humanising this aspect of practice, (b) identifying that family engagement is central to the dying process, (c) increasing emotional responsiveness and (d) showing that care shifts, not stops. (3) The project offers experiential education by (a) intentional role modelling, (b) facilitating EOL dialogue, (c) empowering residents to care in a tangible way and (d) encouraging reflection.

CONCLUSIONS

For residents, the 3 Wishes Project integrated many forms of active learning for residents. Practice-based rather than classroom-based programmes may engage trainees to develop EOL skills transferable to other settings.

Mimicking and Understanding the Agglutination Effect of the Antimicrobial Peptide Thanatin Using Model Phospholipid Vesicles

Thanatin is a cationic 21-residue antimicrobial and antifongical peptide found in the spined soldier bug Podisus maculiventris. It is believed that it does not permeabilize membranes but rather induces the agglutination of bacteria and inhibits cellular respiration. To clarify its mode of action, lipid vesicle organization and aggregation propensity as well as peptide secondary structure have been studied using different membrane models. Dynamic light scattering and turbidimetry results show that specific mixtures of negatively charged and zwitterionic phospholipid vesicles are able to mimic the agglutination effect of thanatin observed on Gram-negative and Gram-positive bacterial cells, while monoconstituent ("conventional") models cannot reproduce this phenomenon. The model of eukaryotic cell reveals no particular interaction with thanatin, which is consistent with the literature. Infrared spectroscopy shows that under the conditions under which vesicle agglutination occurs, thanatin exhibits a particular spectral pattern in the amide I' region and in the region associated with Arg side chains. The data suggest that thanatin mainly retains its hairpin structure, Arg residues being involved in strong interactions with anionic groups of phospholipids. In the absence of vesicle agglutination, the peptide conformation and Arg side-chain environment are similar to those observed in solution. The data show that a negatively charged membrane is required for thanatin to be active, but this condition is insufficient. The activity of thanatin seems to be modulated by the charge surface density of membranes and thanatin concentration.

Phase I study of Aplidine in a dailyx5 one-hour infusion every 3 weeks in patients with solid tumors refractory to standard therapy. A National Cancer Institute of Canada Clinical Trials Group study: NCIC CTG IND 115

BACKGROUND

Aplidine is a cyclic depsipeptide isolated from the marine tunicate Aplidium albicans.

METHODS

This phase I study of Aplidine given as a 1-hour i.v. infusion daily for 5 days every 3 weeks was conducted in patients with refractory solid tumors. Objectives were to define the dose limiting toxicities, the maximal tolerated dose, and the recommended phase II dose.

RESULTS

Thirty-seven patients were accrued on study. Doses ranged from 80 microg/m(2) to 1500 microg/m(2)/day. Eleven patients received more than three cycles of Aplidine. Dose-limiting toxicities occurred at 1500 microg/m(2) and 1350 microg/m(2)/day and consisted of nausea, vomiting, myalgia, fatigue, skin rash and diarrhea. Mild to moderate muscular pain and weakness was noted in patients treated with multiple cycles with no significant drug related neurotoxicity. Bone marrow toxicity was not observed. The recommended dose for phase II studies was 1200 microg/m(2) daily for 5 days, every 3 weeks. Pharmacokinetic studies performed during the first cycle demonstrated that therapeutic plasma levels of Aplidine are reachable well below the recommended dose. Nine patients with progressive disease at study entry had stable disease and two had minor responses, one in non-small cell lung cancer and one in colorectal cancer.

CONCLUSIONS

Aplidine given at a dose of 1200 microg/m(2) daily for 5 days, every 3 weeks is well tolerated with few severe adverse events. This schedule of Aplidine is under evaluation in phase II studies in hematological malignancies and solid tumors.

Oestradiol decreases rat apolipoprotein AI transcription via promoter site B

Oestrogens protect against ischaemic heart disease in the post-menopausal female by increasing serum concentrations of apolipoprotein (apo) AI and the abundance of high-density lipoprotein particles. In men and experimental male animals, the administration of oestrogen has variable effects on apo AI expression. As the major mode of oestrogen action on target genes involves regulating promoter activity and hence transcription, oestrogen is expected to alter transcription of the apo AI gene. To test this hypothesis, the effect of 17beta-oestradiol (E(2)), on rat apo AI promoter activity in male hepatoma HuH-7 cells, was tested by co-transfecting a reporter template, pAI.474.CAT containing-474 to-7 of the rat apo AI promoter and an oestrogen receptor (ER) expression vector, pCMV-ER. Transfected cells exposed to E(2) showed a dose-dependent decrease in chloramphenicol acetyltransferase (CAT)-activity, with a maximum 91+/-1.5% reduction at 1 microM E(2). Deletional analysis of the promoter localized the inhibitory effect of ER and E(2) to site B (-170 to-144) with an adjacent 5' contiguous motif, site S (-186 to-171) acting as an amplifier. HuH-7 cell nuclear extracts showed binding activities with both sites S and B, but recombinant human ER did not. Furthermore, nuclear extracts from E(2)-treated HuH-7 cells showed weaker binding activity to site B, but not to site S. In summary, the inhibitory effect of ER and E(2) on rat apo AI gene activity is mediated by a promoter element, site B. This inhibitory effect arises from a mechanism that does not involve direct ER binding to the B-element. The conclusion that E(2) inhibits apo AI transcription was confirmed in vivo. Treatment of male adult Sprague-Dawley rats with up to 200 microg E(2) for 7 days decreased apo AI protein and hepatic mRNA by 72+/-21% and 68+/-1.4% respectively. Results of 'run-on' transcription of the apo AI gene in isolated hepatic nuclei showed a 55% decrease in hormone-treated male rats. These findings suggest that E(2) exerts primarily an inhibitory effect within male hepatic nuclei.

New adenovirus vectors for protein production and gene transfer

Based on two new adenovirus expression cassettes, we have constructed a series of Ad transfer vectors for the overexpression of one or two genes either in a dicistronic configuration or with separate expression cassettes. Inclusion of the green or blue fluorescent protein in the vectors accelerates the generation of adenovirus recombinants and facilitates the functional characterization of genes both in vitro and in vivo by allowing easy quantification of gene transfer and expression. With our optimized tetracycline-regulated promoter (TR5) we have generated recombinant adenoviruses expressing proteins, that are either cytotoxic or which interfere with adenovirus replication, at levels of 10-15% of total cell protein. Proteins that are not cytotoxic can be produced at levels greater than 20% of total cell protein. As well, these levels of protein production can be achieved with or without adenovirus replication. This yield is similar to what can be obtained with our optimized human cytomegalovirus-immediate early promoter-enhancer (CMV5) for constitutive protein expression in non-complementing cell lines. Using the green fluorescent protein as a reporter, we have shown that a pAdCMV5-derived adenovirus vector expresses about 6-fold more protein in complementing 293 cells and about 12-fold more in non- complementing HeLa cells than an adenovirus vector containing the standard cytomegalovirus promoter. Moreover, a red-shifted variant of green fluorescent protein incorporated in one series of vectors was 12-fold more fluorescent than the S65T mutant, making the detection of the reporter protein possible at much lower levels of expression.

Pilot phase I-II study on 5-aza-2'-deoxycytidine (Decitabine) in patients with metastatic lung cancer

5-Aza-2'-deoxycytidine (5-AZA-CdR, Decitabine) is a nucleoside analog and an active drug for the therapy of acute leukemia. The incorporation of 5-AZA-CdR into DNA blocks DNA methylation and can result in the activation of specific genes, such as tumor suppressor genes. This novel mechanism of action of 5-AZA-CdR stimulated our interest in its potential for cancer therapy in patients with lung cancer. Using a colony assay we observed that 5-AZA-CdR showed a potent antineoplastic effect against two human lung carcinoma cell lines. The objective of this preliminary phase I-II study was to evaluate the toxicity and clinical efficacy of 5-AZA-CdR in patients with stage IV non-small cell lung carcinoma. There were 15 patients that entered the clinical study. For nine assessable patients that received 5-AZA-CdR by a single 8 h i.v. infusion of 200-660 mg/m2 for one or more cycles, the median survival duration was 6.7 months, with three patients surviving more than 15 months. The steady-state plasma concentration of 5-AZA-CdR during the infusion was estimated in some patients and was in the same range that produced activation of a tumor suppressor gene in human lung tumor cell lines as reported by other investigators. The major side effect of 5-AZA-CdR was hematopoietic toxicity which required a 5-6 week recovery period before the next cycle of therapy. This study suggests that 5-AZA-CdR may have some clinical activity against metastatic lung carcinoma using this type of dose schedule.

Improved adenovirus vector provides herpes simplex virus ribonucleotide reductase R1 and R2 subunits very efficiently

We have constructed a new adenovirus (Ad) expression vector, pAdBM5, that allows for the production of unprecedented levels of recombinant protein in the human 293 cell line using the Ad expression system. The main feature of this vector is a combination of enhancer sequences that increases the activity of the ectopic major late promoter (MLP) in recombinant Ad. In 293 cells infected with helper-free Ad recombinants generated with the pAdBM5 transfer vector, both herpes simplex virus (HSV) ribonucleotide reductase R1 and R2 subunits represent the most abundant polypeptides, accounting for as much as 15-20% of total cellular proteins. Our data suggest that this level of expression is probably very close to the upper limit of the system. Furthermore, when compared to the widely utilized baculovirus (Bac)/Sf9 expression system, the improved Ad vector showed a better performance for the production and purification of active HSV-2 ribonucleotide reductase R1 and R2 subunits. The R2 subunit was about 5-fold more abundant in recombinant Ad-infected 293 cells than in Bac-infected Sf9 cells while the R1 subunit was produced at roughly similar levels with either system. However, the amount of active soluble R1 obtained from recombinant Ad-infected 293 cells was at least 5 times higher because most of the R1 produced in Sf9 cells was insoluble.

The importance of dose scheduling with mitoxantrone, 5-fluorouracil and leucovorin in metastatic breast cancer

We have studied a mitoxantrone, 5-fluorouracil (5-FU) and leucovorin chemotherapy regimen in metastatic breast cancer. 8 patients received mitoxantrone 10 mg/m2 on day 1, leucovorin 200 mg/m2 and 5-FU 300 mg/m2 on days 1-5 by intravenous bolus every 28 days in a pilot study. Grades 3-4 granulocytopenia followed 55% of the courses, with 2 patients admitted for febrile neutropenia. Only a 29% objective response rate was seen in a subsequent phase II trial using reduced mitoxantrone doses. Comparison with other trials suggested that 5-day bolus 5-FU administration adversely affects the combination's therapeutic index.

Identification and sequencing of the spheroidin gene of Choristoneura biennis entomopoxvirus

Entomopoxviruses are a class of insect viruses whose virions are embedded in cytoplasmic occlusion bodies. The major component of these protective complexes is a protein called spheroidin. An open reading frame encoding the spheroidin gene of Choristoneura biennis entomopoxvirus has been identified and sequenced in our laboratory. This protein coding region is 1023 nucleotides long and specifies a polypeptide of 38,500 Da. Spheroidin was purified by SDS polyacrylamide gel electrophoresis, electroeluted, and its amino terminus sequence was determined on a gas phase sequencer. We observed that the first 20 N-terminal amino acids were absent in the mature processed form of the spheroidin molecule. Examination of these 20 residues revealed their hydrophobic nature and close resemblance to the consensus signal peptide sequence which is commonly found on membrane proteins. The DNA sequence of the spheroidin gene predicted a processed polypeptide with a molecular weight of 36 kDa. However, spheroidin was observed to aggregate in complexes composed of 50-kDa monomers. Intermolecular disulfide bonds were shown to play major roles in the formation and structure of these viral occlusion bodies. The difference in molecular weight between the predicted protein and its counterpart in infected cells is likely due to post-translational modifications. Indeed, two potential asparagine-linked glycosylation sites are present on the spheroidin molecule. The 5' flanking regions of the spheroidin gene and the vaccinia major core protein precursor gene P4b were shown to share substantial homology.

Oculomotor and vestibular findings in autosomal recessive spastic ataxia of Charlevoix-Saguenay

Electronystagmographic recordings were made of oculomotor and vestibular function in 11 patients with autosomal recessive spastic ataxia of Charlevoix-Saguenay. All had horizontal gaze nystagmus, marked impairment of smooth ocular pursuit and optokinetic nystagmus, and defective fixation suppression of caloric nystagmus. Many had saccadic dysmetria, but saccade velocity was probably unaffected. Abnormalities pointing to brainstem disturbance were sparse. The findings are thought to indicate mainly diffuse cerebellar disease, with particular involvement of vermis and vestibulo-cerebellum.