A146 BENIGN GASTRIC ULCER COMPLICATED BY GASTROJEJUNAL FISTULA FORMATION HEALED WITH PROTON-PUMP INHIBITOR

Background

We report a case of a benign gastric ulcer (GU) complicated by gastrojenunal (GJ) fistulization which healed with proton-pump inhibitor (PPI) therapy. It presented in an elderly malnourished patient.

Purpose

To highlight this rare complication of benign peptic ulcer disease, as only 13 similar cases are reported. Additionally, our case is one of the few demonstrating medical treatment can effectively heal both the ulcer and GJ fistula, thus obviating the need for surgery.

Method

A detailed chart review was conducted to summarize all salient clinical data. Using PubMed database, a comprehensive literature review identified similar cases using MeSH terms such as “gastrojejunal”, “fistula”, and “ulcer” under the case report filter.

Result(s)

An 83-year-old previously healthy woman presented with four weeks of weakness, abdominal pain, and nausea. She denied any overt GI bleeding or NSAID use. Physical exam demonstrated cachexia (36.6kg) with benign abdominal and rectal examinations. Initial workup revealed anemia (hemoglobin of 38g/L), iron deficiency, hypoalbuminemia (20g/L) and depleted B12 (108pmol/L). She was started on IV pantoprazole and transfused 3 units of red cells.

A gastroscopy revealed a giant, penetrating gastric ulcer at the lesser curvature. The ulcer base showed protruding tissue consistent with a segment of intestine (Figure 1 - left image). Examination to the distal duodenum was normal. Biopsies of the ulcer edge were negative for neoplasia. Urease testing of antrum and body samples were negative. CT scan demonstrated a 3.1 cm gastric ulcer with a linear tract communicating with the proximal jejunum, confirming the endoscopic impression.

Surgical consultation was obtained; conservative treatment was advised given her age and cachexia. Calorie intake was optimized and the patient commenced twice daily PPI. She rapidly gained 7 kg in the community, accompanied by normalization of albumin (33g/L) and B12 (293 pmol/L) levels. Hemoglobin remained stable near 100g/L after initial transfusion. At month three, repeat gastroscopy was performed. The ulcer and fistula had completely healed. (Figure 1 - right image).

Image

Conclusion(s)

Gastro-enteric fistulas complicating benign ulcers are rare. When described, other sites, such as gastroduodenal, are more common. Direct gastrojejunal fistulization is less favorable due to the anatomy of the mesentery. The literature reports only 13 gastrojejunal fistulas complicating benign ulcers. In other cases, unique risk factors are reported (malignancy, prior gastric surgery). Only 3 of 13 reported cases resolved with medication alone. The overwhelming majority required surgery. Notably, many of the case reports pre-date the introduction of proton-pump inhibitors.

The etiology of our patient’s ulcer was benign but remains undefined. ASA use was excluded on history, and H. pylori sampling was negative. We speculate profound malnutrition placed her at risk for poor healing and thus contributed to the extensive disease complicated by fistula.

Please acknowledge all funding agencies by checking the applicable boxes below

None

Disclosure of Interest

None Declared

Exploring the Challenges of Frailty in Medical Education

Frailty is common, and medical students and doctors across all specialties will look after patients with frailty. The General Medical Council requires UK medical schools to teach and assess on frailty, and national geriatric societies across the globe include frailty in their recommended undergraduate curricula. However, frailty in medical education is challenging; there is uncertainty around what frailty is in medical education, including how and when to teach it; controversies in mapping teaching and assessments to recommended curricula; patients with frailty can be challenging to include in teaching and assessments due to functional, sensory, and/or cognitive impairments; an individual with frailty is likely to present atypically, with less predictable recovery, introducing complexities into clinical reasoning that can be challenging for students; the term frailty is often negatively perceived, used colloquially and avoided in educational interactions. This commentary discusses these challenges around frailty in undergraduate medical education and serves to provoke discussion about why frailty is so challenging to teach and learn about, including recommendations for how frailty education could be improved.

Care navigation increases initiation of hepatitis C treatment following release from prison in a prospective randomised controlled trial: The C-LINK Study

Background

Prison-based hepatitis C treatment is safe and effective; however, many individuals are released untreated due to time or resource constraints. On community re-entry, individuals face a number of immediate competing priorities, and in this context, linkage to hepatitis C care is low. Interventions targeted at improving healthcare continuity after prison release have yielded positive outcomes for other health diagnoses; however, data regarding hepatitis C transitional care are limited.

Methods

We conducted a prospective randomized controlled trial comparing a hepatitis C care navigator intervention with standard of care for individuals released from prison with untreated hepatitis C infection. The primary outcome was prescription of hepatitis C direct-acting antivirals (DAA) within 6 months of release.

Results

Forty-six participants were randomized. The median age was 36 years and 59% were male. Ninety percent (n = 36 of 40) had injected drugs within 6 months before incarceration. Twenty-two were randomized to care navigation and 24 were randomized to standard of care. Individuals randomized to the intervention were more likely to commence hepatitis C DAAs within 6 months of release (73%, n = 16 of 22 vs 33% n = 8 of 24, P < .01), and the median time between re-entry and DAA prescription was significantly shorter (21 days [interquartile range {IQR}, 11–42] vs 82 days [IQR, 44–99], P = .049).

Conclusions

Care navigation increased hepatitis C treatment uptake among untreated individuals released from prison. Public policy should support similar models of care to promote treatment in this high-risk population. Such an approach will help achieve hepatitis C elimination as a public health threat.

Gelation Dynamics upon Pressure-Induced Liquid-Liquid Phase Separation in a Water-Lysozyme Solution

Employing X-ray photon correlation spectroscopy, we measure the kinetics and dynamics of a pressure-induced liquid-liquid phase separation (LLPS) in a water-lysozyme solution. Scattering invariants and kinetic information provide evidence that the system reaches the phase boundary upon pressure-induced LLPS with no sign of arrest. The coarsening slows down with increasing quench depths. The g₂ functions display a two-step decay with a gradually increasing nonergodicity parameter typical for gelation. We observe fast superdiffusive (γ ≥ 3/2) and slow subdiffusive (γ < 0.6) motion associated with fast viscoelastic fluctuations of the network and a slow viscous coarsening process, respectively. The dynamics age linearly with time τ ∝ t_w, and we observe the onset of viscoelastic relaxation for deeper quenches. Our results suggest that the protein solution gels upon reaching the phase boundary.

Micro-elimination of hepatitis C among people with HIV coinfection: declining incidence and prevalence accompanying a multi-center treatment scale-up trial

BACKGROUND

Gay and bisexual men (GBM) are a key population affected by HIV and hepatitis C (HCV) co-infection. Providing HCV treatment scale-up across specialist and non-hepatitis specialist settings may eliminate HCV in this population. We aimed to (1) deliver and measure HCV treatment effectiveness, and (2) determine the population impact of treatment on HCV prevalence and incidence longitudinally.

METHODS

The co-EC Study (Enhancing care and treatment among HCV/HIV co-infected individuals to Eliminate Hepatitis C transmission) was an implementation trial providing HCV direct-acting antiviral treatment in Melbourne, Australia, from 2016-2018. Individuals with HCV/HIV co-infection were prospectively enrolled from primary and tertiary-care services providing care for 85% of GBM with HIV in our jurisdiction. HCV-viraemic prevalence and HCV-antibody/viraemic incidence were measured using a state-wide, individually-linked, electronic surveillance system.

RESULTS

Among 200 participants recruited, 186 initiated treatment during the study period. Sustained virological response among primary care participants (98%, 95%CI:93-100%) was not different to tertiary care (98%, 95%CI:86-100%). From 2012-2019, between 2434 and 3476 GBM with HIV-infection attended our primary-care sites annually providing 13,801 person-years of follow-up; 50-60% received an HCV test annually, 10-14% were anti-HCV positive. Among those anti-HCV positive, viraemic prevalence declined 83% during the study (54% to 9%; 2016 to 2019). HCV incidence decreased 25% annually from 1.7/100 person-years in 2012 to 0.5/100 person-years in 2019 (incidence rate ratio 0.75; CI:0.68-0.83;p<0.001).

CONCLUSION

High treatment effectiveness by non-specialists demonstrates the feasibility of treatment scale-up in this population. Substantial declines in HCV incidence and prevalence among GBM with HIV-infection provides proof-of-concept for HCV micro-elimination.

REGISTRATION

ClinicalTrials.gov (Identifier: NCT02786758).

Influence of thermally induced structure changes in diluted β-lactoglobulin solutions on their surface activity and behavior in foam fractionation

Surface activity is an intrinsic protein feature, leading to the capability of aqueous protein solutions to form foam. This feature provides opportunities for downstream processing, such as usage of foam fractionation for purification. In order to investigate the impact of the surface activity on the performance of the foam fractionation process, protein solutions with different surface activity were produced by different thermal denaturation of aqueous β-lactoglobulin solutions. The effectiveness of the denaturation procedure was verified with circular dichroic spectroscopy, and the impact on surface activity was determined via dynamic surface tension measurement. The increased surface activity resulted in higher foamate flow rates. Furthermore, the effects could be correlated with secondary structure changes and with the dynamic surface pressure. The new result of this study is that the effect of the denaturation of a protein on foam fractionation depends on the protein concentration. At the lower feed concentration, effects became visible, which could not be observed at the higher concentration.

Influence of cosolvents, self-crowding, temperature and pressure on the sub-nanosecond dynamics and folding stability of lysozyme

We studied the effects of temperature and hydrostatic pressure on the dynamical properties and folding stability of highly concentrated lysozyme solutions in the absence and presence of the osmolytes trimethylamine-N-oxide (TMAO) and urea. Elastic incoherent neutron scattering (EINS) was applied to determine the mean-squared displacement (MSD) of the protein's hydrogen atoms to yield insights into the effects of these cosolvents on the averaged sub-nanosecond dynamics in the pressure range from ambient up to 4000 bar. To evaluate the additional effect of self-crowding, two protein concentrations (80 and 160 mg mL^-1) were used. We observed a distinct effect of TMAO on the internal hydrogen dynamics, namely a reduced mobility. Urea, on the other hand, revealed no marked effect and consequently, no counteracting effect in an urea-TMAO mixture was observed. Different from the less concentrated protein solution, no significant effect of pressure on the MSD was observed for 160 mg mL^-1 lysozyme. The EINS experiments were complemented by Fourier-transform infrared (FTIR) spectroscopy measurements, which led to additional insights into the folding stability of lysozyme under the various environmental conditions. We observed a stabilization of the protein in the presence of the compatible osmolyte TMAO and a destabilization in the presence of urea against temperature and pressure for both protein concentrations. Additionally, we noticed a slight destabilizing effect upon self-crowding at very high protein concentration (160 mg mL^-1), which is attributable to transient destabilizing intermolecular interactions. Furthermore, a pressure-temperature diagram could be obtained for lysozyme at these high protein concentrations that mimics densely packed intracellular conditions.

Co-solvent effects on reaction rate and reaction equilibrium of an enzymatic peptide hydrolysis

This work presents an approach that expresses the Michaelis constant KaM and the equilibrium constant K_th of an enzymatic peptide hydrolysis based on thermodynamic activities instead of concentrations.

Crowding effects on the temperature and pressure dependent structure, stability and folding kinetics of Staphylococcal Nuclease

FT-IR spectroscopic, small-angle X-ray scattering and calorimetric measurements have been applied to explore the effect of the macromolecular crowder agent Ficoll on the temperature- and pressure-dependent stability diagram and folding reaction of the protein Staphylococcal Nuclease (SNase). Additionally, we compare the experimental data with approximate theoretical predictions. We found that temperature- and pressure-induced equilibrium unfolding of SNase is markedly shifted to higher temperatures and pressures in 30 wt% Ficoll solutions. The structure of the unfolded state ensemble does not seem to be strongly influenced in the presence of the crowder. Self-crowding effects have been found to become important at SNase concentrations above 10 wt% only. Our kinetic results show that the folding rate of SNase decreases markedly in the presence of Ficoll. These results indicate that besides the commonly encountered excluded volume effect, other factors need to be considered when assessing confinement effects on protein folding kinetics. Among those, crowder-induced viscosity changes seem to be prominent.

The corneal endothelium as a standard for the assessment of complications in microsurgery

Endothelial cell morphology is an important parameter for the quality control of different surgical techniques, especially in the anterior segment. The minimizing effect of hyaluronic acid in implant surgery can be demonstrated by the decrease of endothelial cell loss as compared to standard techniques. Besides, we can show that the implantation of artificial lenses into the capsular bag is less traumatizing to the cornea than anterior chamber lenses. Other factors to control the surgical techniques are the keratoplastics, especially modified to different trephination techniques and last but not least YAG laser surgery of the cataract membranes. In the latter, there is a direct correlation between endothelial trauma and distance of focus and total energy. Even in isolated cases we can draw conclusions from endothelial morphology to intra-postoperative complications. New surgical techniques which could lead to damage of the cornea should be tested by endothelial cell analysis.

Activity of ivermectin long-acting injectable (IVOMEC(®) GOLD) in first-season grazing cattle exposed to natural challenge conditions in Germany

The persistent activity of ivermectin long-acting injection (IVM LAI; IVOMEC® GOLD, Merial; 3.15% ivermectin w/v) against nematode infections of cattle was evaluated under natural challenge conditions. Seventy nematode-free Brown Swiss calves were blocked by pre-treatment bodyweight and allocated randomly to seven groups of 10 animals each: saline (control) at 1 mL/50 kg bodyweight once on day 0 or IVM LAI at 1 mL/50 kg bodyweight (630 mcg IVM/kg) on either days 0, 7, 14, 21, 28, or 35. After housing until day 35, calves were grazed as one herd on a naturally contaminated pasture for 42 days. Calves were then weighed and housed for 4 weeks before being necropsied for parasite counting. Treatment with IVM LAI prevented the establishment (>90%, p < 0.05) of Dictyocaulus viviparus (100%), Bunostomum phlebotomum (100 %), Haemonchus contortus (98.6%), Ostertagia ostertagi/lyrata (94.9%), and Oesophagostomum radiatum (93.3%) for at least 77 days; Ostertagia leptospicularis (99.1%) for 63 days; Cooperia punctata (97.7%), Trichostrongylus axei (96.5%), and Ostertagia spp. inhibited larvae 4 (93.3%) for 56 days; Cooperia oncophora/surnabada (96.9%), Trichuris discolor (93.6%), and Cooperia spp. inhibited larvae 4 (98.8%); and Nematodirus spp. inhibited larvae 4 (97.1%) for 42 days. Calves of groups treated with IVM LAI had significantly (p < 0.001) higher days 0 to 77 weight gains than the saline-treated controls (28.40-39.25 vs 2.60 kg); the weight gains of the IVM LAI-treated groups, however, were not different from one another (p > 0.3). This study demonstrated a very high efficacy of IVOMEC® GOLD in preventing the establishment of a wide range of bovine nematodes for extended periods of time which was associated with a significant benefit to productivity in terms of weight gain.

Thermodynamic, dynamic and solvational properties of PDEδ binding to farnesylated cystein: a model study for uncovering the molecular mechanism of PDEδ interaction with prenylated proteins

The protein PDEδ is an important solubilizing factor for several prenylated proteins including the Ras subfamily members. The binding occurs mainly through the farnesyl anchor of Ras proteins, which is recognized by a hydrophobic pocket of PDEδ. In this study, we carried out a detailed study of the thermodynamic and solvational properties of PDEδ binding to farnesyl-cystein, which serves as a model for PDEδ association to prenylated proteins. Using various biophysical approaches in conjunction with theoretical considerations, we show here that binding of the largely hydrophobic ligand surprisingly has enthalpy-driven signature, and the entropy change is largely controlled by the fine balance between the hydrational and conformational terms. Moreover, binding of PDEδ to farnesyl-cystein is accompanied by an increase in thermal stability, the release of about 150 water molecules from the interacting species, a decrease in solvent accessible surface area, and a marked decrease of the volume fluctuations and hence dynamics of the protein. Altogether, our results shed more light on the molecular mechanism of PDEδ interaction with prenylated Ras proteins, which is also prerequisite for an optimization of the structure-based molecular design of drugs against Ras related diseases and for understanding the multitude of biological functions of PDEδ.

PAH-CALUX, an optimized bioassay for AhR-mediated hazard identification of polycyclic aromatic hydrocarbons (PAHs) as individual compounds and in complex mixtures

Polycyclic aromatic hydrocarbons (PAHs) represent a class of ubiquitously occurring environmental compounds that are implicated in a wide range of toxicological effects. Routine measurement of PAH contamination generally involves chemical analytical analysis of a selected group of representatives, for example, EPA-16, which may result in underestimation of the PAH-related toxicity of a sample. Many high molecular weight PAHs are known ligands of the aryl hydrocarbon receptor (AhR), a nuclear receptor that mediates toxic effects related to these compounds. Making use of this property we developed a PAH CALUX assay, a mammalian, H4IIe- cell-based reporter assay for the hazard identification of total PAH mixtures. The PAH CALUX reporter cell line allows for specific, rapid (4 h exposure time) and reliable quantification of AhR-induced luciferase induction relative to benzo[a]pyrene (BaP), which is used as a positive reference PAH congener. Full dose response relationships with inductions over 100-fold were reached within only 2 h of exposure to BaP. The PAH CALUX is highly sensitive, that is, using a 4 h exposure time, a limit of detection (LOD) of 5.2 × 10(-11) M BaP was achieved, and highly accurate, that is, a repeatability of 5.9% and a reproducibility of 6.6% were established. Screening of a selection of PAHs that were prioritized by the European Union and/or the U.S. Environmental Protection Agency showed that the PAH CALUX bioassay has a high predictability, particularly for carcinogenic PAHs. Experiments with synthetic mixtures and reference materials containing complex PAH mixtures show the suitability of the assay for these types of applications. Moreover, the presented results suggest that application of the PAH CALUX will result in a lower risk of underestimation of the toxicity of a sample than chemical analytical approaches that focus on a limited set of prioritized compounds.