A256 INCIDENCE OF CIRRHOSIS AMONG RECENT IMMIGRANTS AND REFUGEES TO ONTARIO, CANADA : A POPULATION-BASED COHORT STUDY

Background

The burden of cirrhosis is increasing in North America where a significant proportion of the population (~20%) is comprised of recent immigrants and refugees. However, the incidence of cirrhosis among this population has not been described.

Purpose

The aim of this study was to describe the incidence of cirrhosis among recent immigrants and refugees to Ontario, Canada stratified by cirrhosis etiology and region of origin and compare incidence rates to those of Canadian-born and long-term residents.

Method

This is a population-based cohort study from Ontario, Canada from 2000-2017 using healthcare data housed at ICES. Individuals with incident cirrhosis using a 5-year lookback were identified along with cirrhosis etiology using validated algorithms. Recent immigrants and refugees to Ontario (since 1985) and their World Bank region of origin were defined based on linkage to the Immigration, Refugees, and Citizenship Canada’s Permanent Resident database. Adjusted incidence rates of cirrhosis by immigration status, etiology, and region of origin were calculated and differences in rates were compared between recent immigrants and refugees to long-term residents (born in Canada or arriving before 1985) using age and sex adjusted Poisson regression to calculate rate ratios (RR).

Result(s)

In total, n=25,054 recent immigrants/refugees with incident cirrhosis were identified. 59% were male, median age was 49 years (IQR 39-61), 99% resided in urban areas and 31% resided in neighbourhoods of the lowest income quintile. The most common regions of origin were East Asia and Pacific (n=8,121; 32%), South Asia (n=5,576; 22%), Europe and Central Asia (n=4,454; 18%) and Latin America/Caribbean (n=3,216; 13%). The majority had NAFLD cirrhosis (n=13,972; 55%), followed by HBV (n=4,648; 19%), ALD (n=2,957; 12%), and HCV (n=2,635; 11%). Cirrhosis incidence stratified by etiology varied by region of origin, with HBV highest among the East Asia and Pacific and Sub-Saharan Africa cohort (Figure 1b), HCV among Sub-Saharan Africa and South Asia (Figure 1c), ALD among European/Central Asia and South Asia (Figure 1d), and NAFLD among the Latin America/Caribbean, Middle East/North Africa, and South Asian populations (Figure 1e). When comparing age and sex adjusted incidence of cirrhosis by etiology and immigration status, rates were lower among recent immigrants/refugees for all causes compared to long-term residents (all RR <1.0; Figure 1a,c-f) with the exception of HBV where it was over 4-fold higher (Figure 1b).

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Conclusion(s)

Rates of HBV cirrhosis are substantially higher among migrants to Ontario while rates of all other causes of cirrhosis are lower, likely explained by the healthy immigrant effect. NAFLD has emerged as the most common etiology of cirrhosis among migrants with rates approaching those of Canadian-born and long-term residents. These data add to our understanding of the evolving epidemiology of cirrhosis and the contribution of other etiologies outside of viral hepatitis among immigrants.

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Concomitant diagnosis of bipolar disorder and tuberous sclerosis - a case report

Introduction

Tuberous sclerosis is a multisystem genetic disorder. It is associated with significant psychiatric comorbidity mainly autistic disorders, hyperkinetic disorders, depression and anxiety. It is rarely associated with psychosis and bipolar disorder.

Objectives

To describe the case of a 34-year-old male with concomitant diagnosis of bipolar disorder and tuberous sclerosis.

Methods

Case report based on clinical records. Brief literature review using articles searched in the PubMed/MEDLINE database using the terms “tuberous sclerosis”, “bipolar disorder” and “neuropsychiatric”.

Results

The patient presented at our Emergency Department 3 years ago with a mixed episode with psychotic symptoms with 1 month of duration. Prior history of two hypomanic episodes, but no depressive episodes. High baseline functionality. Sporadic use of alcohol and cannabis. No family history of psychiatric or neurological diseases. Diagnostic work-up showed no relevant results, aside from small calcifications in brain CT. He was admitted to our ward and medicated with aripiprazol (titrated up to 30 mg), leading to full remission of the clinical picture. The patient was referred to our outpatient clinic and stayed with medication for 1,5 years. One year after, he presented a sudden episode of mutism and perplexity with quick remission. The EEG wielded no relevant results. New brain CT showed signs of tuberous sclerosis. He was referred to Neurology and subsequent assessments, including brain MRI, led to the fulfilment of clinical criteria for tuberous sclerosis.

Conclusions

This case illustrates the possibility of concomitant diagnosis of bipolar disorder and tuberous sclerosis. The possible association between these disorders is discussed.

Disclosure

No significant relationships.

Topologically driven linear magnetoresistance in helimagnetic FeP

The helimagnet FeP is part of a family of binary pnictide materials with the MnP-type structure, which share a nonsymmorphic crystal symmetry that preserves generic band structure characteristics through changes in elemental composition. It shows many similarities, including in its magnetic order, to isostructural CrAs and MnP, two compounds that are driven to superconductivity under applied pressure. Here we present a series of high magnetic field experiments on high-quality single crystals of FeP, showing that the resistance not only increases without saturation by up to several hundred times its zero-field value by 35 T, but that it also exhibits an anomalously linear field dependence over the entire range when the field is aligned precisely along the crystallographic c-axis. A close comparison of quantum oscillation frequencies to electronic structure calculations links this orientation to a semi-Dirac point in the band structure, which disperses linearly in a single direction in the plane perpendicular to field, a symmetry-protected feature of this entire material family. We show that the two striking features of magnetoresistance-large amplitude and linear field dependence-arise separately in this system, with the latter likely due to a combination of ordered magnetism and topological band structure.

LIVE procedure for ischemic heart failure: the evolution of an unique technique

Background

Ischemic cardiomyopathy is the leading cause of heart failure. In patients with left ventricular (LV) dilatation, low ejection fraction, and transmural scar in an anteroseptal distribution, surgical ventricular reconstruction (SVR) is a treatment option. However, SVR is an invasive procedure which often cannot be offered to patients with ischemic cardiomyopathy due to other comorbidities. Less Invasive Ventricular Enhancement (LIVE) technique is a unique intervention to exclude scarred myocardium, improving symptoms and quality of life.

Methods

LIVE procedure has evolved from open sternotomy to a hybrid procedure done with right internal jugular vein access and a left minithoracotomy. LV shape and size is restored without extracorporeal circulation by plication of the scarred myocardium. This is achieved by implantation of a series of internal and external microanchors brought together over a poly-ether-ether-ketone (PEEK) tether to make a longitudinal approximation between the LV free wall and the anterior septum. Internal anchors are deployed by a transcatheter technique, through the right internal jugular vein, on the right side of the ventricular septum.

Results

Between July 2018 and January 2020, 47 patients (84.4% men; mean age 61±12.5 years) were submitted to the LIVE procedure in 16 Institutions in Europe, North America and Asia. Procedural success was 100%. There was no intra-hospital mortality. A mean of 2.3 anchor pairs (median 2) were used to reshape the LV. Echocardiographic data showed an increase in LV ejection fraction (EF) from 31.4±9.2% to 40.0±12.4% (change +29.8%, p<0.001) and LV end-systolic volume index (LVESVI) reduction from 66.6±29.3 ml/m2 to 40.7±21.5 ml/m2 (change −38%, p<0.001) and LV end-diastolic volume index (LVEDVI) reduction from 92.8±39.2 ml/m2 to 60.6±25.9 ml/m2 (change −33.2%, p=0.001) after the procedure. Sternotomy conversion was needed in one patient due to right ventricular perforation. New onset tricuspid valve regurgitation was observed in one patient. There was no case of ventricular septal defect. In the mean follow-up period of 9.8 months, NYHA class improved a median of 1 grade and there was no late mortality.

Conclusion

Hybrid LV reshaping and volume reduction has proven to be a useful option for patients with symptomatic heart failure after left anterior descending territory myocardial infarction. These results from the latest iteration of the technique show that this approach is safe and has a significant short and mid-term impact on improving EF and reduction in LV.

LIVE procedure

Funding Acknowledgement

Type of funding source: None

Ca2+ sensitivity of synaptic vesicle dopamine, gamma-aminobutyric acid, and glutamate transport systems

The effect of Ca2+ on the uptake of neurotransmitters by synaptic vesicles was investigated in a synaptic vesicle enriched fraction isolated from sheep brain cortex. We observed that dopamine uptake, which is driven at expenses of the proton concentration gradient generated across the membrane by the H+-ATPase activity, is strongly inhibited (70%) by 500 microM Ca2+. Conversely, glutamate uptake, which essentially requires the electrical potential in the presence of low Cl- concentrations, is not affected by Ca2+, even when the proton concentration gradient greatly contributes for the proton electrochemical gradient. These observations were checked by adding Ca2+ to dopamine or glutamate loaded vesicles, which promoted dopamine release, whereas glutamate remained inside the vesicles. Furthermore, similar effects were obtained by adding 150 microM Zn2+ that, like Ca2+, dissipates the proton concentration gradient by exchanging with H+. With respect to gamma-aminobutyric acid transport, which utilizes either the proton concentration gradient or the electrical potential as energy sources, we observed that Ca2+ or Zn2+ do not induce great alterations in the gamma-aminobutyric acid accumulation by synaptic vesicles. These results clarify the nature of the energy source for accumulation of main neurotransmitters and suggest that stressing concentrations of Ca2+ or Zn2+ inhibit the proton concentration gradient-dependent neurotransmitter accumulation by inducing H+ pump uncoupling rather than by interacting with the neurotransmitter transporter molecules.

Distinction between Ca(2+) pump and Ca(2+)/H(+) antiport activities in synaptic vesicles of sheep brain cortex

Synaptic vesicles, isolated from a sheep brain cortex, accumulate Ca(2+) in a manner that depends on the pH and pCa values. In the presence of 100 microM CaCl(2), most of the Ca(2+) taken up by the vesicles was vanadate-inhibited (86%) at pH 7.4, whereas at pH 8.5, part of the Ca(2+) accumulated (36%) was DeltapH-dependent (bafilomycin and CCCP inhibited) and part was insensitive to those drugs (31%). We also observed that both vanadate-sensitive and bafilomycin-sensitive Ca(2+) accumulations were completely released by the Ca(2+) ionophore, ionomycin, and that these processes work with high (K(0.5)=0.6 microM) and low (K(0.5)=217 microM) affinity for Ca(2+), respectively. The DeltapH-dependent Ca(2+) transport appears to be largely operative at Ca(2+) concentrations (>100 microM) which completely inhibited the vanadate-sensitive Ca(2+) uptake. These Ca(2+) effects on the Ca(2+) accumulation were well correlated with those observed on the vanadate-inhibited Ca(2+)-ATPase and bafilomycin-inhibited H(+)-ATPase, respectively. The Ca(2+)-ATPase activity reached a maximum at about 25 microM (pH 7.4) and sharply declined at higher Ca(2+) concentrations. In contrast, Ca(2+) had a significant stimulatory effect on the H(+)-ATPase between 250 and 500 microM Ca(2+) concentration. Furthermore, we found that DeltapH-sensitive Ca(2+) transport was associated with proton release from the vesicles. About 21% of the maximal proton gradient was dissipated by addition of 607.7 microM CaCl(2) to the reaction medium and, if CaCl(2) was present before the proton accumulation, lower pH gradients were reached. Both vanadate-inhibited and bafilomycin-inhibited systems transported Ca(2+) into the same vesicle pool of our preparation, suggesting that they belong to the same cellular compartment. These results indicate that synaptic vesicles of the sheep brain cortex contain two distinct mechanisms of Ca(2+) transport: a high Ca(2+) affinity, proton gradient-independent Ca(2+) pump that has an optimal activity at pH 7.4, and a low Ca(2+) affinity, proton gradient-dependent Ca(2+)/H(+) antiport that works maximally at pH 8.5.

Methods for analysis of Ca(2+)/H(+) antiport activity in synaptic vesicles isolated from sheep brain cortex

The involvement of Ca(2+)-storage organelles in the modulation of synaptic transmission is well-established [M.K. Bennett, Ca(2+) and the regulation of neurotransmitter secretion, Curr. Opin. Neurobiol. 7 (1997) 316-322 [1]; M.J. Berridge, Neuronal calcium signaling, Neuron 21 (1998) 13-26 [2]; Ph. Fossier, L. Tauc, G. Baux, Calcium transients and neurotransmitter release at an identified synapse, Trends Neurosci. 22 (1999) 161-166 [7] ]. Various Ca(2+) sequestering reservoirs (mitochondria, endoplasmic reticulum and synaptic vesicles) have been reported at the level of brain nerve terminals [P. Kostyuk, A. Verkhratsky, Calcium stores in neurons and glia, Neuroscience 63 (1994) 381-404 [18]; V. Mizuhira, H. Hasegawa, Microwave fixation and localization of calcium in synaptic terminals using X-ray microanalysis and electron energy loss spectroscopy imaging, Brain Res. Bull. 43 (1997) 53-58 [21]; A. Parducz, Y. Dunant, Transient increase of calcium in synaptic vesicles after stimulation, Neuroscience 52 (1993) 27-33 [23]; O.H. Petersen, Can Ca(2+) be released from secretory granules or synaptic vesicles?, Trends Neurosci. 19 (1996) 411-413 [24] ]. However, the knowledge of the specific contribution of each compartment for spatial and temporal control of the cytoplasmic Ca(2+) concentration requires detailed characterization of the Ca(2+) uptake and Ca(2+) release mechanisms by the distinct intracellular stores. In this work, we described rapid and simple experimental procedures for analysis of a Ca(2+)/H(+) antiport system that transport Ca(2+) into synaptic vesicles at expenses of the energy of a DeltapH generated either by activity of the proton pump or by a pH jumping of the vesicles passively loaded with protons. This secondary active Ca(2+) transport system requires high Ca(2+)100 microM) for activation, it is dependent on the chemical component (DeltapH) of the proton electrochemical gradient across the synaptic vesicle membrane and its selectivity is essentially determined by the size of the transported cation [P.P. Gonçalves, S.M. Meireles, C. Gravato, M.G. P. Vale, Ca(2+)-H(+)-Antiport activity in synaptic vesicles isolated from sheep brain cortex, Neurosci. Lett. 247 (1998) 87-90 [10]; P.P. Gonçalves, S.M. Meireles, P. Neves, M.G.P. Vale, Ionic selectivity of the Ca(2+)/H(+) antiport in synaptic vesicles of sheep brain cortex, Mol. Brain Res. 67 (1999) 283-291 [11]; P.P. Gonçalves, S.M. Meireles, P. Neves, M.G.P. Vale, Synaptic vesicle Ca(2+)/H(+) antiport: dependence on the proton electrochemical gradient, Mol. Brain Res. 71 (1999) 178-184 [12] ]. The protocols described here allow to ascertain the characteristics of the Ca(2+)/H(+) antiport in synaptic vesicles and, therefore, may be useful for clarification of the physiological role of synaptic vesicles in fast buffering of Ca(2+) at various sites of the neurotransmission machinery.

Shoe manufacturing and solvent exposure in northern Portugal

Shoe manufacturing is a traditional industry in northern Portugal. There are nearly 1500 factories that employ about 54,000 workers. Among the materials used in the shoe manufacturing process, that could be occupational hazards, are the adhesives, especially adhesives solutions based on organic solvents. The National Institute of Health (Oporto Branch) carried out a study of 100 factories in northern Portugal to study solvent exposure in shoe manufacturing. The surveyed population, (4615 workers) was young (mean age = 33 years; range = 18-45) and predominantly female (68.5%). The results from the air samples analyses show 20 different organic compounds existing in the workplaces. The more common compounds found were n-hexane, toluene, and acetone. The results of the study show that in 53.7 percent of the factories there are operations where the solvent exposure is significant and represents a health hazard to the workers. These operations are mainly gluing, waxing, and polishing stations. Occupational risk of exposure to solvents concerned 44.2 percent of the workers. This study points out the existence of inadequate ventilation in the workplaces and inappropriate personal protective equipment to prevent dermatitis risk from adhesives, wax, and polish. The organic solvents present in workplaces also increase fire risk.

Synaptic vesicle Ca2+/H+ antiport: dependence on the proton electrochemical gradient

Synaptic vesicles isolated from sheep brain cortex accumulate Ca2+ by a mechanism of secondary active transport associated to the H(+)-pump activity. The process can be visualized either by measuring Ca(2+)-induced H+ release or DeltapH-dependent Ca2+ accumulation. We observed that the amount of Ca2+ taken up by the vesicles increases with the magnitude of the DeltapH across the membrane, particularly at Ca2+ concentrations (approximately 500 microM) found optimal for the antiporter activity. Similarly, H+ release induced by Ca2+ increased with the magnitude of DeltapH. However, above 60% DeltapH (high H(+)-pump activity), the net H+ release from the vesicles decreased as the pump-mediated H+ influx exceeded the Ca(2+)-induced H+ efflux. We also observed that the Ca2+/H+ antiport activity depends, essentially, on the DeltapH component of the electrochemical gradient (approximately 3 nmol Ca2+ taken up/mg protein), although the Deltaphi component may also support some Ca2+ accumulation by the vesicles (approximately 1 nmol/mg protein) in the absence of DeltapH. Both Ca(2+)-induced H+ release and DeltapH-dependent Ca2+ uptake could be driven by an artificially imposed proton motive force. Under normal conditions (H+ pump-induced DeltapH), the electrochemical gradient dependence of Ca2+ uptake by the vesicles was checked by inhibition of the process with specific inhibitors (bafilomycin A(1), ergocryptin, folymicin, DCCD) of the H(+)-pump activity. These results indicate that synaptic vesicles Ca2+/H+ antiport is indirectly linked to ATP hydrolysis and it is essentially dependent on the chemical component (DeltapH) of the electrochemical gradient generated by the H(+)-pump activity.

Ionic selectivity of the Ca2+/H+ antiport in synaptic vesicles of sheep brain cortex

As we previously reported, synaptic vesicles isolated from sheep brain cortex contain a Ca2+/H+ antiport that permits Ca2+ accumulation inside the vesicles ( approximately 5 nmol/mg protein) at expenses of the pH gradient generated by the H+-pumping ATPase. We observed that the system associates Ca2+ influx to H+ release and operates with low affinity for Ca2+. In the present work, we found that Ca2+/H+ antiport mediates exchange of protons with other cations such as Zn2+ and Cd2+, suggesting that these cations and Ca2+ share the same transporter molecules to enter the intravesicular space. Zn2+ and Cd2+ induce H+ release in a concentration-dependent manner (fluorimetrically evaluated) and they inhibit the antiport-mediated Ca2+ uptake by the vesicles (isotopically measured). In contrast, large cations such as Ba2+ and Cs+ do not alter Ca2+ influx and they are unable to induce proton release from the vesicles. With respect to Sr2+, which has an intermediary size relatively to the other groups of cations, we found that it does not induce H+ liberation from the vesicles, but it has a concentration-dependent inhibitory effect on the Ca2+-induced H+ release and Ca2+ uptake by the vesicles. These results indicate that the cation selectivity of the synaptic vesicles Ca2+/H+ antiport is essentially determined by the size of the cation transported into the vesicles.

Resource management in the Cronus distributed operating system

Cronus [1-7] is an object oriented distributed system which operates in a heterogeneous computer environment of interconnected local area networks. As a distributed system architecture. Cronus faces a number of resource management issues not present in non-distributed architectures. Strategies for effectively controlling the redundancy and reconfigurability inherent in Cronus are needed to take advantage of the distributed system environment. These strategies for resource management are often conveniently separated into policies and mechanisms. A policy is a goal or guideline set by a system administrator or component designer constraining the decisions made by a resource allocator. A mechanism is an internal system structure designed to implement a class of policies.

In the Cronus distributed system model, there are currently two general aspects of resource allocation mechanisms which are particular to the network environment and must be effectively managed. One of these is the binding of a client request to a particular resource manager for those resources which are available redundantly. Redundancy comes in two forms: replicated objects, (e.g., a multi-copy file) and replicated managers (any manager for a type can create a new instance of that object type). For both forms the selection of an object manager to provide the given service is an important resource management policy decision. The other important aspect of resource management mechanism is the ability to reconfigure parts of the system by dynamically migrating objects. Object migration is a powerful tool for matching system resources to tasks in a manner that attempts to maximize some measure of system performance, reliability, or survivability. Both static reconfiguration (e.g., choosing or amending the placement of object managers and their associated objects), and dynamic reconfiguration (e.g., moving an individual object in direct response to demand for its use possible in the Cronus architecture and design.

The general approach to resource management in Cronus is to individually control the management of the classes of objects which make up the system. This approach extends Cronus resource management concepts beyond system resources to the abstract resources developed by applications. Resource management for an individual abstract resource (type) and for groups of related resource types (services) in Cronus is based on combining a number of carefully planned mechanisms which are part of the system architecture. In addition to resource management by resource type, a client specific policy which considers collections of object types used in a specific context can be constructed.

In Cronus we achieve system wide and easily controllable resource management by requiring the object managers to cooperate in enforcing a resource management policy for their resource type. An object manager can redirect operations to a peer manager on another processor on the basis of current resource status. In the case for creation of a file to an alternate file manager which may have more storage available. Part of the basis for decisions to redirect requests are parameters, settable dynamically by system administrators through monitoring and control functions, which control the resource management strategy. The creation of objects and resource management in general thus becomes a responsibility that is decentralized among object managers on each processor based on a global allocation policy, both in terms of sharing current status and possible redirection of operations between managers.

The Cronus resource management model is based on the integration of the following set of primitive mechanisms:

There is a hierarchy of desirable locations for implementing resource management policies: object managers, shared libraries, and finally client programs or users themselves. Managers are the most desirable because they are readily identifiable with a limited set of object types which are likely to have similar policy goals. Also, managers are addressable as a group for administrative control to regulate the policy parameters, and for peer manager cooperation to implement the policy. Many decisions are negotiated between managers based upon information periodically obtained via the ReportStatus operation. The Cronus Monitoring and Control System uses the same ReportStatus operation to present the operator with a global view of how well the resource management policy is proceeding.

In this paper we elaborate on these approaches to distributed resource management in Cronus, including appropriate background, detailed system design, and experiences with incorporating these ideas into three different resource managers.

Chronic gastritis and peptic ulcer

The relationship between chronic gastritis and peptic ulcer was studied in 97 patients, 51 with duodenal ulcer and 46 with gastric ulcer. Six biopsies (three from the antrum and three from the body) were obtained under direct vision by means of an Olympus panendoscope. Chronic gastritis was classified according to the grade of inflammation (slight or moderate and intense), and to its location (antritis or pangastritis). In gastric ulcer the relationship between frequency of chronic gastritis and the site of the ulcer (antrapyloric, at the angulus, body of the stomach) was also established. Antritis was just as frequently observed in duodenal ulcer (94%) as in gastric patients (96%), but severe inflammation of the antrum was higher in G.U. (43%) than in D.U. (17%). Chronic gastritis of the gastric body was always accompanied by antritis, both in G.U. and in D.U. and was observed in 63% of the former group and 37% of the latter. Severe inflammation of the glandular portion of the stomach occurred in only one patient with D.U (2%) and in 7 with G. U (15%). In the present investigation, no relationship between between the site of gastric ulcer and the frequency of chronic gastritis was observed.