The 2022 Vaccines Against Shigella and Enterotoxigenic Escherichia coli (VASE) Conference: Summary of abstract-based presentations

The global nonprofit organization PATH hosted the third Vaccines Against Shigella and Enterotoxigenic Escherichia coli (VASE) Conference in Washington, DC, on November 29 to December 1, 2022. With a combination of plenary sessions and posters, keynote presentations, and breakout workshops, the 2022 VASE Conference featured key updates on research related to the development of vaccines against neglected diarrheal pathogens including Shigella, enterotoxigenic Escherichia coli (ETEC), Campylobacter, and Salmonella. The presentations and discussions highlighted the significant impact of these diarrheal pathogens, particularly on the health of infants and young children in low- and middle-income countries, reflecting the urgent need for the development and licensure of new enteric vaccines. Oral and poster presentations at the VASE Conference explored a range of topics, including: the global burden and clinical presentation of disease, epidemiology, and the impact of interventions; the assessment of the value of vaccines against enteric pathogens; preclinical evaluations of vaccine candidates and models of enteric diseases; vaccine candidates in clinical trials and human challenge models; host parameters and genomics that predict responses to infection and disease; the application of new omics technologies for characterization of emerging pathogens and host responses; novel adjuvants, vaccine delivery platforms, and immunization strategies; and strategies for combination/co-administered vaccines. The conference agenda also featured ten breakout workshop sessions on topics of importance to the enteric vaccine field, which are summarized separately. This article reviews key points and highlighted research presented in each of the plenary conference sessions and poster presentations at the 2022 VASE Conference.

A step towards routine for stereotactic radioablation in refractory ventricular tachycardia – interim analysis on short term safety of the first prospective, multi-centre, multi-platform study RAVENTA

Background

Ventricular tachycardia (VT) is a potentially life-threatening heart rhythm disorder originating in heterogeneous conduction velocity in the ventricular myocardium, e.g. by scar formation in ischaemic or dilated cardiomyopathy. Current guideline-directed medical therapy comprises implantable cardioverter defibrillator (ICD), antiarrhythmic drugs, and endocardial/epicardial catheter ablation. There is a serious recurrence rate for example due to diffuse fibrosis, progress of disease, or insufficient ablation depth or volume.

In cases when Catheter ablation and antiarrhythmic medication failed to reduce VT burden, stereotactic body radiation therapy (SBRT) may become an additional treatment option. To date there have been several small retrospective case series and some single-centre prospective studies showing promising results.

Purpose

For the purpose of obtaining the authorization of a randomized trial, a feasibility study was designed. The primary objective is to demonstrate sufficient safety of cardiac SBRT for the non-invasive treatment of VT and whether the dose needed can be delivered while sparing sensitive surrounding structures (e.g. stomach, oesophagus, vena cava, coronary arteries, ICD). Secondarily, the effect on VT burden is reported.

Methods

The RAVENTA study (RAdiosurgery for VENtricular TAchycardias) is the first prospective, multicentre study on SBRT in patients suffering from refractory VTs worldwide. Patients were enrolled according to strict inclusion criteria. First, an electrophysiology study using a high definition mapping system was performed to identify the substrate (target region). In order to plan SBRT a planning computed tomography scan was obtained. Finally, a single dose of 25 Gy was administered to the target region. Neither sedation nor anaesthesia is necessary during SBRT.

Primary endpoint is feasibility defined as complete dose application and absence of severe (grade ≥3) treatment-related toxicity within 30 days of treatment. RAVENTA is powered to reject the hypothesis of 70% feasibility, if in fact feasibility is 95%. This is a pre-defined interim analysis with the aim of stopping early for futility.

Results

Between October 2019 and December 2021, the first 5 patients (characteristics shown in Table 1) could be enrolled and radiotherapy was delivered without major complications. Cardiac SBRT took on average 30 minutes. There was no treatment-related severe toxicity. Furthermore, we could not record any negative effect on functionality of the ICD: constant sensing amplitude and pacing capture threshold. In the short-term, patients showed a clear decrease in VT burden.

Conclusion

These preliminary data of the first multi-centre, multi-platform study on cardiac SBRT on refractory VT demonstrated sufficient short-term feasibility to continue the RAVENTA study. Meanwhile the study has been expanded to 6 centres in Germany.

Funding Acknowledgement

Type of funding sources: None.

Cystic angiomatosis of the bone, liver, and spleen

Introduction/Objective

Cystic angiomatosis is a very rare entity characterized by multifocal cystic angiomatous lesions of the skeletal system, occasionally involving visceral organ systems. Clinical presentation and progression are extremely variable. Cases with liver involvement are even rarer, and have been described as invariably fatal. The pathogenesis of this disorder is poorly understood, and no treatments are currently available.

Methods/Case Report

A 24 year old man with history of polysubstance abuse and untreated hepatitis C presented with acute abdominal pain. Imaging revealed hepatosplenomegaly and multiple liver, spleen, and skeletal lesions. Differential diagnoses included metastatic disease, lymphoma, and infection. Apart from known untreated chronic hepatitis C, all infectious, autoimmune and hypercoagulability work-ups were negative. Biopsies of the liver and iliac bone lesions showed areas of benign-appearing vascular proliferation in a background of fibrosis. The vascular endothelial cells were positive for CD34 and CD31 but negative for D2-40. On follow-up approximately eight months later, the patient was asymptomatic.

Results (if a Case Study enter NA)

NA

Conclusion

Liver involvement by cystic angiomatosis is exceedingly rare and has been associated with increased mortality. This case provides an example of a patient with incidentally discovered cystic angiomatosis involving liver, spleen, and bone who remains asymptomatic at follow-up. Additional cases are required to understand the pathophysiology and disease course in this group of patients, and to investigate possible therapeutic targets.

How genomics can be used to understand host susceptibility to enteric infection, aiding in the development of vaccines and immunotherapeutic interventions

Thanks to the modern sequencing era, the extent to which infectious disease imposes selective pressures on the worldwide human population is being revealed. This is aiding our understanding of the underlying immunological and host mechanistic defenses against these pathogens, as well as potentially assisting in the development of vaccines and therapeutics to control them. As a consequence, the workshop "How genomics can be used to understand host susceptibility to enteric infection, aiding in the development of vaccines and immunotherapeutic interventions" at the VASE 2018 meeting, aimed to discuss how genomics and related tools could be used to assist Shigella and ETEC vaccine development. The workshop featured four short presentations which highlighted how genomic applications can be used to assist in the identification of genetic patterns related to the virulence of disease, or host genetic factors that could contribute to immunity or successful vaccine responses. Following the presentations, there was an open debate with workshop attendees to discuss the best ways to utilise such genomic studies, to improve or accelerate the process of both Shigella and ETEC vaccine development. The workshop concluded by making specific recommendations on how genomic research methods could be strengthened and harmonised within the ETEC and Shigella research communities.

Acupuncture reduces the time from extubation to 'ready for discharge' from the post anaesthesia care unit: results from the randomised controlled AcuARP trial

Acupuncture may improve peri-operative care as it reduces post-operative symptoms, such as pain, nausea and vomiting, or sedation. This patient-assessor blinded, randomised trial in 75 women undergoing gynaecologic laparoscopy evaluated the effects of acupuncture combined with a standardised anaesthetic regimen (ACU) on post-anaesthetic recovery, when compared to acupressure (APU) or standard anaesthesia alone (CON). Main outcome measure was the time from extubation to ‘ready for discharge’ from recovery as assessed by validated questionnaires. The main outcome differed significantly between groups (p = 0.013). Median time to ready for discharge in the ACU group (30 (IQR: 24–41) min) was 16 minutes (35%) shorter than in the CON group (46 (36–64) min; p = 0.015) and tended to be shorter than in the APU group (43 (31–58) min; p = 0.08). Compared to CON (p = 0.029), median time to extubation was approximately 7 minutes shorter in both, the ACU and the APU group. No acupuncture or acupressure-related side-effects could be observed. A difference in time to recovery of 16 minutes compared to standard alone can be considered clinically relevant. Thus, results of this study encourage the application of acupuncture in gynaecological laparoscopy as it improves post-anaesthetic recovery.

Neural therapy of an athlete's chronic plantar fasciitis: a case report and review of the literature

Background

The focus of this case report is on the role of inflammation as a contributor to pain in plantar fasciitis and its cure by the injection of local anesthetics.

Case presentation

This is a case report on a 24-year-old white man, a middle-distance runner, with chronic unilateral plantar fasciitis and perceived heel pain for almost 1.5 years. He was treated with neural therapy (that is, injection of < 1 ml procaine 1% which is a local anesthetic with strong anti-inflammatory properties) of the surgical scar and along the surgical puncture channel. The follow-up period from the time of first presentation until publication was 2.5 years. At admission, pain intensity (visual analog scale) in the affected leg was severe (10 cm, visual analog scale; range 0–10 cm) when walking and moderate (5 cm, visual analog scale) when standing. After the first session of injections he could stand pain-free and pain when walking was markedly reduced (− 90%). After the third session, he reported no pain in the affected leg and could return to sports at his former level (no difference in training load compared to non-injured state). There was no recurrence of inflammatory signs or heel pain despite intense athletics training up to the date of publication.

Conclusions

In prolonged cases of plantar fasciitis, inflammation is an important component in the development of persistent pain. The results of our case describe the effects of three neural therapy sessions that abolished inflammation and associated heel pain. Neural therapy might be an effective and time-efficient approach in the treatment of plantar fasciitis, enabling an early return to sports.

Effects of aerobic exercise on brain metabolism and grey matter volume in older adults: results of the randomised controlled SMART trial

There is mounting evidence that aerobic exercise has a positive effect on cognitive functions in older adults. To date, little is known about the neurometabolic and molecular mechanisms underlying this positive effect. The present study used magnetic resonance spectroscopy and quantitative MRI to systematically explore the effects of physical activity on human brain metabolism and grey matter (GM) volume in healthy aging. This is a randomised controlled assessor-blinded two-armed trial (n=53) to explore exercise-induced neuroprotective and metabolic effects on the brain in cognitively healthy older adults. Participants (age >65) were allocated to a 12-week individualised aerobic exercise programme intervention (n=29) or a 12-week waiting control group (n=24). The main outcomes were the change in cerebral metabolism and its association to brain-derived neurotrophic factor (BDNF) levels as well as changes in GM volume. We found that cerebral choline concentrations remained stable after 12 weeks of aerobic exercise in the intervention group, whereas they increased in the waiting control group. No effect of training was seen on cerebral N-acetyl-aspartate concentrations, nor on markers of neuronal energy reserve or BDNF levels. Further, we observed no change in cortical GM volume in response to aerobic exercise. The finding of stable choline concentrations in the intervention group over the 3 month period might indicate a neuroprotective effect of aerobic exercise. Choline might constitute a valid marker for an effect of aerobic exercise on cerebral metabolism in healthy aging.

Range of motion and cervical myofascial pain

Several studies investigating myofascial pain syndrome include assessments of range of motion (ROM) as a diagnostic criterion. However, the value of ROM in this context has not yet been evaluated in controlled clinical studies. We aimed to examine whether patients with myofascial pain syndrome display alterations of ROM when compared to healthy subjects. Twenty-two individuals (13 females, 9 males; aged 33.4 ± 13.9 yrs) afflicted with active myofascial trigger points in the upper trapezius muscle as well as 22 age and sex matched healthy controls were included. All subjects underwent an examination of maximal active cervical ROM in flexion/extension assessed by means of a 3D ultrasonic movement analysis system (30 Hz; Zebris CMS 70). In the patients group, pressure pain threshold (PPT) of the trigger points was determined using a pressure algometer. Maximum range of motion in the sagittal plane did not differ between individuals with MTrP (125.9 ± 23.2°, 95% CI: 116.2-135.6°) and asymptomatic subjects (128.2 ± 20.4°, 95% CI: 119.7-136.7°; p > .05). In patients, PPT (1.7 ± .6, 95% CI: 1.5-1.9) was not correlated with cervical mobility (r = -.13; p > .05). Based on these pilot data, range of motion in flexion/extension is not a valid criterion for the detection of myofascial trigger points. Additional research incorporating movement amplitudes in other anatomical planes and additional afflicted muscles should be conducted in order to further delineate the relative impact of MTrP on range of motion.

[Gender aspects in anesthesia : modified approach in research and treatment?]

Gender differences can have a relevant influence on the perioperative outcome as male and female patients are affected differently by adverse events, e.g. side effects of drugs. Furthermore, differences relating to specific drug effects, comorbidities and outcome after anesthesia or intensive care have been demonstrated. There seems to be a gender bias in diagnosis and therapy. While the knowledge regarding this field is still growing certain aspects have already been integrated into clinical practice: prevention of postoperative nausea and vomiting (PONV), target controlled infusion (TCI) model and male only policy with production of blood products. There is a need to study the influence of gender, age and race in order to optimize treatment towards a more individualized therapy. This article highlights already identified differences and discusses potential underlying mechanisms.

Clinical relevance of different dose calculation strategies for mediastinal IMRT in Hodgkin's disease

BACKGROUND AND PURPOSE

Conventional algorithms show uncertainties in dose calculation already for three-dimensional conformal radiotherapy (3D-CRT). Intensity-modulated radiotherapy (IMRT) might even increase these. We wanted to assess differences in dose distribution for pencil beam (PB), collapsed cone (CC), and Monte Carlo (MC) algorithm for both 3D-CRT and IMRT in patients with mediastinal Hodgkin lymphoma.

PATIENTS AND METHODS

Based on 20 computed tomograph (CT) datasets of patients with mediastinal Hodgkin lymphoma, we created treatment plans according to the guidelines of the German Hodgkin Study Group (GHSG) with PB and CC algorithm for 3D-CRT and with PB and MC algorithm for IMRT. Doses were compared for planning target volume (PTV) and organs at risk.

RESULTS

For 3D-CRT, PB overestimated PTV(95) and V(20) of the lung by 6.9% and 3.3% and underestimated V(10) of the lung by 5.8%, compared to the CC algorithm. For IMRT, PB overestimated PTV(95), V(20) of the lung, V(25) of the heart and V(10) of the female left/right breast by 8.1%, 25.8%, 14.0% and 43.6%/189.1%, and underestimated V(10) of the lung, V(4) of the heart and V(4) of the female left/right breast by 6.3%, 6.8% and 23.2%/15.6%, compared to MC.

CONCLUSION

The PB algorithm underestimates low doses to the organs at risk and overestimates dose to PTV and high doses to the organs at risk. For 3D-CRT, a well-modeled PB algorithm is clinically acceptable; for IMRT planning, however, an advanced algorithm such as CC or MC should be used at least for part of the plan optimization.

[Acupuncture in emergency medicine : results of a case series]

BACKGROUND

Acupuncture (AP) might be indicated in emergency medicine. This case series was performed to demonstrate the practicability and possible effects of AP in emergency medical services (EMS) as a basis for randomized controlled trials (RCT).

SUBJECTS AND METHODS

A total of 60 patients (average age 55.4±23.0 years, 57% female) treated by the EMS received AP if applicable. Main outcome parameter was to rate the symptom alleviating effect of acupuncture treatment on a 4-point scale or by VAS.

RESULTS

Of the 60 patients 35 (58%) reported considerable improvement, 15 patients (25%) reported complete relief and 10 patients (17%) reported no changes in the cardinal symptom. The predominant symptoms alleviated by AP were nausea (n=31) and vomiting (n=21). Pericardium 3 and 6 (27%) and Spleen 6 and 9 were the most commonly used AP points.

CONCLUSION

This case series demonstrates that AP can alleviate certain symptoms in emergency patients. The results of the study provide data as a basis to perform clinical controlled trials on the effectiveness of AP in emergency medicine.

Low concentrations of amitriptyline inhibit nicotinic receptors in unmyelinated axons of human peripheral nerve

BACKGROUND AND PURPOSE

Amitriptyline is often prescribed as a first-line treatment for neuropathic pain but its precise mode of analgesic action remains uncertain. Amitriptyline is known to inhibit voltage-dependent ion channels and also to act as an antagonist at ligand-gated ion channels, such as nicotinic acetylcholine receptors (nAChRs). In the present study, we tested the effect of amitriptyline on nicotinic responses of unmyelinated axons in isolated segments of human peripheral nerve. In particular, a comparison was made between the concentrations of amitriptyline necessary for inhibition of nAChRs and those required for inhibition of the compound C-fibre action potential.

EXPERIMENTAL APPROACH

Isolated axon fascicles were prepared from short segments of human sural nerve, and multiple measures of axonal excitability were recorded using computer-controlled threshold tracking software.

KEY RESULTS

Amitriptyline (EC(50) 2.6 microM) reduced the nicotine-induced increase in C-fibre excitability but only slightly altered the amplitude and latency to onset of the compound action potential. In contrast, tetrodotoxin produced a clear reduction in the amplitude and a prolongation of action potential onset latency but was without effect on the nicotine-induced increase in axonal excitability.

CONCLUSIONS AND IMPLICATIONS

These data demonstrate that low concentrations of amitriptyline suppress the response of human peripheral C-type axons to nicotine by directly inhibiting nAChRs. Blockade of tetrodotoxin-sensitive, voltage-dependent sodium channels does not contribute to this effect. An inhibitory action of amitriptyline on nAChRs in unmyelinated nociceptive axons may be an important component of amitriptyline's therapeutic effect in the treatment of neuropathic pain.

Retigabine reduces the excitability of unmyelinated peripheral human axons

Enhancement of membrane K(+) conductance may reduce the abnormal excitability of primary afferent nociceptive neurons in neuropathic pain. It has been shown that retigabine, a novel anticonvulsant, activates Kv7 (KCNQ/M) channels in the axonal/nodal membrane of peripheral myelinated axons. In this study, we have tested the effects of retigabine on excitability parameters of C-type nerve fibers in isolated fascicles of human sural nerve. Application of retigabine (3-10 microM) produced an increase in membrane threshold. This effect was pronounced in depolarized axons and small in hyperpolarized axons. This finding indicates that retigabine produces a membrane hyperpolarization which is limited by the K(+) equilibrium potential. The retigabine-induced reduction in excitability was accompanied by modifications of the post-spike recovery cycle. Most notable is the development of a late subexcitability at 250-400 ms following a short burst of action potentials. All effects of retigabine were blocked in the presence of XE991 (10 microM). The data show that Kv7 channels are present on axons of unmyelinated, including nociceptive, peripheral human nerve fibers. It is likely that activation of these channels by retigabine may reduce the ectopic generation of action potentials in neuropathic pain.