The Usefulness of Salivary Gland Organoids for Evaluation of the Potency of Botulinum Neurotoxin

BACKGROUND AND OBJECTIVES

Botulinum neurotoxin (BoNT) is a substance used to treat chronic sialorrhea, muscle dystonia, and is used in cosmetic applications. Measuring the potency of BoNT is crucial because it acts even with a small amount. However, the current methods for measuring the potency of BoNT involve using two-dimensional neuroblastoma cell line-based methods. In this study, we aimed to develop a new method to measure the potency of BoNT using a three-dimensional organoid culture system.

MATERIALS AND METHOD

We established the optimal conditions for coculturing N2a neuronal cells with murine salivary gland organoids (SGOs). After determining the appropriate chemical concentrations, we treated the SGOs cocultured with N2a cells with BoNT type A (BoNT/A). We confirmed the expression of salivary gland-related genes and proteins using real-time polymerase chain reaction (PCR) and immunofluorescence staining.

RESULTS

The SGOs cocultured with N2a cells showed that the dendrites or axons of neuronal cells were in contact with the outermost layer of the SGOs. When we applied acetylcholine and neostigmine to the coculture systems, the mRNA expression of Aqp5 and Bhlha15, associated with salivary gland secretory cells, increased. However, this effect was reversed when BoNT/A was applied, as confirmed through real-time PCR.

CONCLUSION

We found that the coculture system of SGOs and N2a neuronal cells can potentially serve as a potency testing platform for BoNT.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:2697-2704, 2024.

Botulinum Toxin and Progressive Pneumoperitoneum in Loss of Domain Ventral Hernias: A Systematic Review

Introduction: Preoperative progressive pneumoperitoneum (PPP) and botulinum toxin A (BTX) have been used together in the preoperative preparation of patients with loss of domain hernias. This study aims to evaluate the efficacy and safety of the combined use of PPP and BTX. Methods: A systematic electronic search was performed according to the PRISMA criteria. A literature search of scientific articles was conducted up to December 2023. Articles were chosen based on the reference to BTX and PPP in loss of domain ventral hernias with a defect width greater than 10 cm before surgery. The GRADE methodology and the modified Newcastle-Ottawa scale were used to assess the quality of the studies. Results: The research yielded seven articles, with 217 patients analysed in total. BTX was performed 29.5 ± 1.7 days before surgery and PPP was inflated 14.8 ± 5.8 days before surgery. PPP complications were reported in 25.6% of patients, The average reduction of the volume of hernia (VH)/volume of the abdominal cavity (VAC) ratio was 7.6% (range 0.9%-15%). Only 40 patients (18.4%) required a PCS or TAR to repair the loss of domain hernias. The SSI and SSO rates were 17.5% and 26.2%, respectively. No differences in SSI and SSO rates were found between the different repair techniques. The recurrence rate was 5.9% (13/217). Recurrence was significantly higher in patients who underwent IPOM repair than other techniques (p < 0.001). Conclusion: BTX and PPP may be useful tools for the management of loss of domain hernias presenting lower SSI and SSO. The combination of BTX and PPP reduces the use of more invasive repair techniques.

Anatomical location and number of injection sites of intravesical OnabotulinumtoxinA for females with refractory idiopathic overactive bladder: A scoping review

AIMS

The negative impact on quality of life and the economic-related burden to the patient and the health care system associated with idiopathic overactive bladder (iOAB) is well-documented. Intradetrusor OnabotulinumtoxinA (BTN/A) injections are a well-used treatment modality for the management of overactive detrusor refractory to medical management, with well-documented efficacy and safety profiles. There is currently no best practice guideline for the administration of BTN/A for this procedure and historically the trigone of the bladder has been excluded from the injection paradigm given the risk of vesicoureteral reflux (VUR).

METHODS

A scoping review methodology was employed to assess available literature to evaluate current techniques used. There is emerging literature that the inclusion of the trigone may increase the efficacy of the procedure, while maintaining a similar adverse effect profile. Similar results could also be obtained by decreasing the number of injection sites. A scoping review was completed with systematic methodology using the Preferred Systematic Reviews and Meta Analyses extension for Scoping Review checklist. The search strategy looked to evaluate BTN/A and number of injection sites and the inclusion of the trigone in female patients with iOAB. Studies with male or neurogenic bladder only were excluded. Mixed studies were included. A specialist research librarian was engaged, with supervision from a functional urologist using a combination of MeSH and natural language terms. Two investigators independently reviewed the titles and abstracts.

RESULTS

Twelve articles were included and were published between 2005 and 2021. There was no evidence of VUR in any of the results. All but one study reported similar if not improved efficacy of trigone-inclusion. Lower number of injection sites had similar efficacy profiles to higher numbers of intradetrusor injections.

CONCLUSIONS

Further high-quality randomized control trials of trigone inclusion and reduction of injection sites are required. It is hoped that with further exploration of intraoperative methods for BTN/A injections, the development of universally accepted guidelines may optimize management and experiences for patients with iOAB.

Efficacy of transurethral botulinum toxin A injections for bladder outlet obstruction: A systematic review and meta-analysis

INTRODUCTION

Botulinum toxin A (BoNT-A) injections in the prostate gland have been used as a minimally invasive option for treating bladder outlet obstruction (BOO). However, the efficacy of transurethral BoNT-A injections for BOO is not well established in the literature. The aim of this study is to collect evidence on the efficacy of transurethral BoNT-A injections for the treatment of BOO.

MATERIALS AND METHODS

This systematic review and meta-analyses was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. A systematic literature search was performed till December 2022. The study population consisted of adult patients diagnosed with BOO, who underwent transurethral injections of BoNT-A for the treatment of BOO.

EVIDENCE SYNTHESIS

Out of 883 records, we identified seven studies enrolling 232 participants, of which only one nonrandomized controlled trial was found. Four prospective studies and two retrospective studies. Three studies included patients with lower urinary tract symptoms (LUTS) and benign prostatic hyperplasia (BPH) and were included in the meta-analysis. Three studies included patients with urethral sphincter hyperactivity. One study included patients with primary bladder neck disease (PBND). All studies showed significant improvements from baseline in maximum urinary flow rate (Qmax), International Prostate Symptom Score (IPSS), and postvoid residual (PVR) at 3 and 6 months. The adverse events were mild in all studies. Hematuria, UTI, and urinary retention were reported across all studies.

CONCLUSION

In conclusion, transurethral BoNT-A injections have been shown to improve LUTS, QoL, and urodynamic parameters of individuals with BOO at 3 and 6 months after injections, and no serious adverse effects have been reported. However, data on the long-term benefits of this treatment are scarce, and more prospective, randomized studies with larger samples examining various injection techniques, dosages, and extended follow-up of recurrent injections are needed.

Intragastric injection of botulinum toxin in the treatment of obesity: a single-center study

Background

In recent years, various novel surgical and non-surgical therapeutic options have been developed for treating obesity. Due to its disputed success, intragastric botulinum toxin A (BTX-A) injection is still being debated.

Objectives

We aim to contribute to this controversial issue in the literature by sharing our center's findings regarding intragastric BTX-A injections in the treatment of obesity.

Design

Patients with a body mass index (BMI) of greater than 25 kg/m2 and at least one obesity-related complication, or a BMI of greater than 30 kg/m2 without complications, were eligible for the study if they were between the ages of 18 and 65.

Methods

Following the same procedure, two endoscopists administered BTX-A to all patients. All patients were evaluated for obesity by measuring their lipid profile, hormone profile, and insulin resistance level before treatment.

Results

In our study on 82 patients, we saw a significant mean weight loss (-9.2 kg, p < 0.001) in the second month, and there was no additional mean weight loss in the sixth month of follow-up. In addition, this result seems to be independent of the patient's insulin resistance. We did not see any serious side effects in any of the patients.

Conclusion

Although the use of intragastric injection of BTX-A in the treatment of obesity is a controversial issue, we showed in our study that it causes significant weight loss. Further studies are needed on this subject, as it can be a safe method when the ideal dose and application site are combined with appropriate patient selection.

Botulinum neurotoxin type A does not exert concentration-dependent effects on equine articular cartilage in vitro

OBJECTIVE

To determine whether Botulinum neurotoxin type A (BoNT-A) ameliorates the effects of interleukin 1 (IL-1) on equine articular cartilage, or exerts negative effects on normal equine articular cartilage homeostasis in vitro.

SAMPLE

Articular cartilage explants from 6 healthy femoropatellar joints of 3 adult horses.

METHODS

Explants were allocated to the IL-1 challenged or unchallenged group, then exposed to 1 of 6 concentrations of BoNT-A (0, 1, 10, 50, 100, or 500 pg/mL) for 96 hours. To assess BoNT-A's effects on inflammation, prostaglandin E2 (PGE2) was measured in media via ELISA. Matrix degradation was determined as the percentage of sulfated glycosaminoglycans (sGAG) released from explants via dimethylmethylene blue assay. Aggrecan synthesis was estimated using CS846 ELISA and collagen type II degradation was estimated using C2C ELISA on media. Chondrocyte apoptosis was assessed via in-situ TUNEL assay. Generalized linear mixed models were fitted to determine treatment effects using α = 0.05.

RESULTS

The challenge with IL-1 resulted in increased concentrations of PGE2 and CS846 in media and increased release of sGAG from explants. BoNT-A did not significantly impact PGE2 or CS846 concentration in media, percentage of sGAG released, or chondrocyte apoptosis in IL-1 challenged or unchallenged cartilage explants. The concentration of C2C in media was below the quantifiable limit of the ELISA in all samples.

CLINICAL RELEVANCE

BoNT-A did not show chondroprotective effects or have negative effects on cartilage homeostasis in vitro at the concentrations tested. While chondroprotective effects were not observed, BoNT-A may be safe for intraarticular use. In vivo testing is warranted before clinical use.

In-Plane Ultrasound-Guided Botulinum Toxin Injection to Lumbrical and Interosseus Upper Limb Muscles: Technical Report

This technical report presents an innovative approach utilizing in-plane ultrasound-guided injections to precisely target the lumbrical and interosseous muscles within the upper limb. The report also elucidates the rationale and advantages of incorporating ultrasound guidance in the administration of Botulinum toxin (BTX) injections, encompassing the real-time visualization of needle trajectory and accurate localization of the target muscle groups while delving into the pertinent anatomical details of these muscles and their significance in diverse neuromuscular conditions. The step-by-step procedure for conducting in-plane ultrasound-guided BTX injections to the lumbrical and interosseous muscles is delineated, emphasizing critical technical considerations and potential pitfalls to be vigilant of during the procedure. Furthermore, the article addresses the significance of selecting appropriate BTX dosages and injection sites based on individual patient presentations and clinical indications. Overall, the in-plane ultrasound-guided BTX injection technique presents a promising approach for providing precise and targeted treatment to the lumbrical and interosseous muscles in the upper limb. It offers clinicians an alternative to injections performed without guidance or out-of-plane ultrasound-guided injections, potentially decreasing the likelihood of complications and enhancing treatment outcomes for patients with a range of neuromuscular conditions. However, further research and comparative studies are necessary to establish the long-term efficacy and safety of this technique, thus confirming its role in clinical practice.

Use of botulinum toxin in aesthetic medicine and gynaecology: current approaches, controversies, and future directions

This review looks at the use of botulinum toxin in the gynaecological field with the aim of determining what needs to be further investigated to achieve a standardized application. Numerous studies have been conducted to explore how botulinum toxins (BoNT) can be applied, and it is becoming popular for treating various disorders such as chronic pelvic pain, vestibulodynia, and vaginism. However, the exact dosage and ideal location for injections still need to be clarified. The objective of this study is to point out which aspects need to be more carefully studied to ensure a consistent use of BoNT in gynaecology.

Replacement of the Mouse LD50 Assay for Determination of the Potency of AbobotulinumtoxinA with a Cell-Based Method in Both Powder and Liquid Formulations

Botulinum neurotoxins (BoNTs) are important therapeutic agents. The in vivo median lethal dose (LD₅₀) assay has been commonly used to measure the potency of BoNT commercial preparations. As an alternative, we developed cell-based assays for abobotulinumtoxinA in both powder (Dysport^®, Azzalure^®) and liquid (Alluzience^®) formulations using the in vitro BoCell^® system. The assays demonstrated linearity over 50-130% of the expected relative potency, with a correlation coefficient of 0.98. Mean recoveries of 90-108% of the stated potency were observed over this range. The coefficients of variation for powder and liquid formulations, respectively, were 3.6% and 4.0% for repeatability and 8.3% and 5.0% for intermediate precision. A statistically powered comparability assessment of the BoCell^® and LD₅₀ assays was performed. Equivalence was demonstrated between the assays for the liquid formulation at release and end of shelf life using a paired equivalence test with predefined equivalence margins. For the powder formulation, the assays were also shown to be equivalent for release samples and when determining loss of potency following thermal degradation. The BoCell^® assay was approved for establishing the potency of abobotulinumtoxinA for both powder and liquid formulations in Europe and for the powder formulation only in the USA.

Physical Treatments to Control Clostridium botulinum Hazards in Food

Clostridium botulinum produces Botulinum neurotoxins (BoNTs), causing a rare but potentially deadly type of food poisoning called foodborne botulism. This review aims to provide information on the bacterium, spores, toxins, and botulisms, and describe the use of physical treatments (e.g., heating, pressure, irradiation, and other emerging technologies) to control this biological hazard in food. As the spores of this bacterium can resist various harsh environmental conditions, such as high temperatures, the thermal inactivation of 12-log of C. botulinum type A spores remains the standard for the commercial sterilization of food products. However, recent advancements in non-thermal physical treatments present an alternative to thermal sterilization with some limitations. Low- (<2 kGy) and medium (3-5 kGy)-dose ionizing irradiations are effective for a log reduction of vegetative cells and spores, respectively; however, very high doses (>10 kGy) are required to inactivate BoNTs. High-pressure processing (HPP), even at 1.5 GPa, does not inactivate the spores and requires heat combination to achieve its goal. Other emerging technologies have also shown some promise against vegetative cells and spores; however, their application to C. botulinum is very limited. Various factors related to bacteria (e.g., vegetative stage, growth conditions, injury status, type of bacteria, etc.) food matrix (e.g., compositions, state, pH, temperature, aw, etc.), and the method (e.g., power, energy, frequency, distance from the source to target, etc.) influence the efficacy of these treatments against C. botulinum. Moreover, the mode of action of different physical technologies is different, which provides an opportunity to combine different physical treatment methods in order to achieve additive and/or synergistic effects. This review is intended to guide the decision-makers, researchers, and educators in using physical treatments to control C. botulinum hazards.

Treatment Results of Vocal Process Granuloma: Intubation versus Contact Granuloma

Introduction  Contact granulomas (CGs) and intubation granulomas (IGs) are known to have different clinical manifestations despite having the same pathological features. Objective  The purpose of the present study was to analyze the treatment results for CG and IG and to obtain clinical information. Methods  We retrospectively reviewed the medical records of patients diagnosed with vocal process granuloma (VPG) between January 2015 and December 2018. The patient's age, sex, medical history, lesion size, lesion type, reflux finding score (RFS), response to treatment, duration of treatment, and follow-up period were compared. Results  Eighteen patients with CG and 14 patients with IG were included in the study. The IG group had more female patients ( p  = 0.0009), showed better response to proton pump inhibitor (PPI) and steroid inhalation (SI) ( p  = 0.036), and had a shorter treatment period ( p  = 0.0029) than the CG group. Five patients who received botulinum toxin injections in their vocal cords had complete remission. Conclusion  Compared with CG, IG was more responsive to treatment with PPI and SI and required a shorter duration of treatment.

2023 update on the clinical management of gastroparesis

INTRODUCTION

Gastroparesis is characterized by symptoms suggesting gastric retention of food and objective evidence of delayed gastric emptying in the absence of a mechanical obstruction. Nausea, vomiting, early satiety, and postprandial fullness are the classic symptoms of gastroparesis. Gastroparesis is increasingly encountered by physicians. There are several recognized etiologies of gastroparesis, including diabetic, post-surgical, medication-induced, post-viral, and idiopathic.

AREAS COVERED

A comprehensive literature review was conducted to identify studies discussing gastroparesis management. Dietary modifications, medication adjustments, glucose control, antiemetic agents, and prokinetic agents are all part of gastroparesis management. In this manuscript, we detail treatments evolving for gastroparesis, including nutritional, pharmaceutical, device, and recent advanced endoscopic and surgical therapies. This manuscript concludes with a speculative viewpoint on how the field will evolve in 5 years' time.

EXPERT OPINION

Identification of the dominant symptoms (fullness, nausea, abdominal pain, and heartburn) helps to direct management efforts of the patients. Treatments for refractory (treatment resistant) symptoms may include gastric electric stimulation and intra-pyloric interventions like botulinum toxin and endoscopic pyloromyotomy. Understanding the pathophysiology of gastroparesis, relating pathophysiologic abnormalities to specific symptoms, new efficacious pharmacotherapies, and better understanding of the clinical predictors of response of therapies, are priorities for future research in the field of gastroparesis.

Current and emerging pharmacological targets and treatments of urinary incontinence and related disorders

The overactive bladder syndrome with and without urinary incontinence and related conditions, signs, and disorders such as detrusor overactivity, neurogenic voiding dysfunction, underactive bladder, stress urinary incontinence, and nocturia are common in the general population and have a major impact on the quality of life of the affected patients and their partners. Based on the deliberations of the subcommittee on pharmacological treatments of the 7^th International Consultation on Incontinence, we present a comprehensive review of established drug targets in the treatment of overactive bladder syndrome and the above-mentioned related conditions and the approved drugs used in its treatment. Investigational drug targets and compounds are also reviewed. We conclude that despite a range of available medical treatment options, a considerable medical need continues to exist. This is largely because the existing treatments are symptomatic and have limited efficacy and/or tolerability, which leads to poor long-term adherence. Significance Statement Urinary incontinence and related disorders are prevalent in the general population. While many treatments have been approved, few patients stay on long-term treatment despite none of them being curative. This manuscript provides a comprehensive discussion of existing and emerging treatment options for various types of incontinence and related disorders.

Crystal structure of the OrfX1-OrfX3 complex from the PMP1 neurotoxin gene cluster

Paraclostridial mosquitocidal protein 1 (PMP1) is a member of the clostridial neurotoxin (CNT) family, which includes botulinum and tetanus neurotoxins. PMP1 has unique selectivity for anopheline mosquitos and is the only known member of the family that targets insects. PMP1 is encoded in an orfX gene cluster, which in addition to the toxin, consists of OrfX1, OrfX2, OrfX3, P47 and NTNH, which have been shown to aid in PMP1 toxicity. We here show that OrfX1 and OrfX3 form a complex and present its structure at 2.7 Å. The OrfX1-OrfX3 complex mimics the structure of full-length OrfX2 and belongs to the lipid-binding TULIP protein superfamily. With this report, the structures of all proteins encoded in the orfX gene cluster of CNTs are now determined.

Correlation of Levator-Muller's Complex Thickness on Ultrasound Biomicroscopy to Botulinum Toxin A Injection in Thyroid-Related Upper Eyelid Retraction

OBJECTIVES

To study the thickness of levator palpebra superioris-Muller's muscle complex (LMC) on ultrasound biomicroscopy (UBM) and to correlate with the clinical response to botulinum toxin A (BTA) injection in patients with inactive-stage of thyroid-related upper eyelid retraction (UER). We also studied the correlation of clinical parameters, preinjection with postinjection values.

METHODS

This was a prospective, interventional study. Patients with thyroid-related UER who underwent subconjunctival injection of BTA were recruited. Demographic data and clinical details were evaluated. UBM (50 MHz) was done to measure the thickness of LMC. Patient's satisfaction was graded at each follow-up. Follow-up was done at 1 week, 1 month, and 3 months' time intervals.

RESULTS

A total of 13 patients were recruited and 26 eyes were divided into two groups; group 1 included eyes with UER (n = 17), and group 2 included eyes without UER (n = 9). There was a statistically significant reduction in margin reflex distance 1 (MRD1) after BTA injection at 1-week, 1-month, and 3-months follow-up with maximum reduction at 1 month. The mean LMC thickness of 26 eyes was 0.96 mm which was found to be significantly more than normal controls. On comparison of mean LMC thickness with the amount of UER and reduction in MRD1, we did not find a significant difference.

CONCLUSIONS

Patients with TED have significantly thicker LMC on UBM than controls. Further studies are needed with a larger sample size on the correlation of UBM features of levator aponeurosis with response to BTA injection.

Intra-Articular Injection of Botulinum Toxin for the Treatment of Knee Osteoarthritis: A Systematic Review of Randomized Controlled Trials

The purpose of the present paper was to review the available evidence on intra-articular botulinum toxin (BTX) injection in the treatment of knee osteoarthritis and to compare it to other conservative treatment options. A systematic review of the literature was performed on the PubMed, Scopus, Cochrane Library, Web of Science, Pedro and Research Gate databases with the following inclusion criteria: (1) randomized controlled trials (RCTs), (2) written in the English language, and (3) published on indexed journals in the last 20 years (2001-2021) dealing with the use of BTX intra-articular injection for the treatment of knee OA. The risk of bias was assessed using the Cochrane Risk of Bias tool for RCTs. Nine studies involving 811 patients in total were included. Patients in the control groups received different treatments: conventional physiotherapy, hyaluronic acid injection or prolotherapy or a combination thereof in 5 studies, steroid infiltrative therapy (triamcinolone) in 1 study, placebo in 2, and local anesthetic treatment in 1 study. Looking at the quality of the available literature, two of the included studies reached "Good quality" standard, three were ranked as "Fair", and the rest were considered "Poor". No major complications or serious adverse events were reported following intra-articular BTX, which provided encouraging pain relief, improved motor function, and quality of life. Based on the available data, no clear indication emerged from the comparison of BTX with other established treatments for knee OA. The analysis of the available RCTs on BTX intra-articular injection for the treatment of knee OA revealed modest methodological quality. However, based on the data retrieved, botulinum toxin has been proven to provide good short-term outcomes, especially in patients with pain sensitization, by modulating neurotransmitter release, peripheral nociceptive transduction, and acting on the control of chronic pain from central sensitization.

Proposal of a Clinical Technique to Quantify Prognosis

Introduction

Masseter hypertrophy presents as unilateral or bilateral swellings over the ramus and angle of the mandible. It is caused by malocclusion, clenching, TMJ disorders, etc and alters facial symmetry, leading to discomfort and negative cosmetic impact in many patients, making this a popular request for aesthetic and functional correction.

Materials and Methods

This case report involves injecting Botulinum toxin into 6 equidistant bulging points on the masseter. Standardized photography and clinical parameters were used to assess facial contour and masseter muscle thickness at baseline and successive follow ups.

Results and Discussion

Significant masseteric bulk reduction was observed in subsequent follow ups.

Conclusion

The 6-point technique was found to be an effective treatment modality for Botox injection in masseteric hypertrophy. The clinical method to quantify prognosis was easy and economical.

Persistence with Botulinum Toxin Treatment for Spasticity Symptoms in Multiple Sclerosis

Botulinum toxin (BT) is an effective treatment for spasticity symptoms in multiple sclerosis (MS). Despite its wide use in clinical practices, only few studies have explored long-term persistence. We aim to evaluate the rate of discontinuation of BT treatment and the correlation with MS, spasticity, and injection variables. This retrospective study on 3-year prospectively collected data included 122 MS patients receiving BT injections for spasticity. We collected MS clinical variables (disease durations, Expanded Disability Status Scales [EDSSs], disease-modifying treatments [DMT], and Symbol Digit Modalities Tests [SDMTs]), modified Ashworth scales [MASs], concomitant treatments, and injection variables (formulation, dose, number of injections, and intervals between injections). A total of 14 out of the 122 patients discontinued BT after a mean time of 3.0 ± 1.5 years. In the Cox regression model including the MS clinical variables, the probability of BT discontinuations increased in patients with DMT changes during follow-ups (HR = 6.34; 95%Cl = 2.47, 18.08; p < 0.01) and with impaired SDMTs (HR = 1.20; 95%Cl = 1.04, 1.96; p < 0.01). In the model including the spasticity variables, there were no associations between BT discontinuation and MAS or other spasticity treatments. In the model including the injection variables, the probability of discontinuation decreased by 80% for each cumulative injection (HR = 0.16; 95%Cl = 0.05, 0.45; p < 0.01), but increased by 1% for each additional day over the 3-month interval between injections (HR = 1.27; 95%Cl = 1.07, 1.83; p < 0.01). BT discontinuation was associated with concomitant MS-related issues (e.g., treatment failure and DMT change) and the presence of cognitive impairment, which should be accounted for when planning injections. The interval between injections should be kept as short as possible from regulatory and clinical perspectives to maximize the response across all of the spasticity symptoms and to reduce discontinuation in the long term.

Therapeutic Approach to Botulinum Injections for Hemifacial Spasm, Synkinesis and Blepharospasm

The aim of this study was to show our therapeutic outcome of botulinum injection to the facial muscles and thereby to find the best therapeutic concept which should be embraced. The decision to treat the lower eyelid with 1-point or 2-points injection was randomly taken as there is no consensus regarding this debate. Injections of the lateral end of the upper eyelid were performed more laterally to the conventional injection point, just lateral to the conjunction of the upper and lower eyelids. Twenty-three patients (12 hemifacial spasm, 6 blepharospasm, 5 post facial palsy synkinesis) were enrolled. Data were retrieved from 112 visits between 2019 and 2022. Overall, 84.9% of the treatments had moderate or marked improvement. The most common side effect was facial weakness (11.8%). Neither ptosis nor diplopia were noted. Two-points regimen in the lower eyelid was associated with a lower risk of facial weakness (p = 0.01), compared to 1-point regimen, with a better therapeutic outcome as reflected by more favorable PGI-C scores (p = 0.04). Injection of the pretarsal segment of the upper eyelid, just onto or even lateral to the conjunction of the upper and lower eyelids, lowers the risk of ptosis.

Endogenous CRISPR-Cas Systems in Group I Clostridium botulinum and Clostridium sporogenes Do Not Directly Target the Botulinum Neurotoxin Gene Cluster

Most strains of proteolytic group I Clostridium botulinum (G1 C. botulinum) and some strains of Clostridium sporogenes possess genes encoding botulinum neurotoxin (BoNT), a potent neuroparalytic agent. Within G1 C. botulinum, conserved bont gene clusters of three major toxin serotypes (bont/A/B/F) can be found on conjugative plasmids and/or within chromosomal pathogenicity islands. CRISPR-Cas systems enable site-specific targeting of previously encountered mobile genetic elements (MGE) such as plasmids and bacteriophage through the creation of a spacer library complementary to protospacers within the MGEs. To examine whether endogenous CRISPR-Cas systems restrict the transfer of bont gene clusters across strains we conducted a bioinformatic analysis profiling endogenous CRISPR-Cas systems from 241 G1 C. botulinum and C. sporogenes strains. Approximately 6,200 CRISPR spacers were identified across the strains and Type I-B, III-A/B/D cas genes and CRISPR array features were identified in 83% of the strains. Mapping the predicted spacers against the masked strain and RefSeq plasmid dataset identified 56,000 spacer-protospacer matches. While spacers mapped heavily to targets within bont(+) plasmids, no protospacers were identified within the bont gene clusters. These results indicate the toxin is not a direct target of CRISPR-Cas but the plasmids predominantly responsible for its mobilization are. Finally, while the presence of a CRISPR-Cas system did not reliably indicate the presence or absence of a bont gene cluster, comparative genomics across strains indicates they often occupy the same hypervariable loci common to both species, potentially suggesting similar mechanisms are involved in the acquisition and curation of both genomic features.

Pharmacological Management of Urinary Incontinence: Current and Emerging Treatment

Pharmacological management of urinary incontinence (UI) is currently based on antimuscarinic and beta-3-agonist drugs. Botulinum toxin A detrusor injections represent an effective but more invasive alternative. This review covers the latest developments of the currently available drugs and the emerging compounds for the treatment of UI. Evidence shows that new antimuscarinics and beta-3-agonists with improved safety profiles may offer unique options to patients intolerant to currently available drugs. Combination therapy proved to be a non-invasive alternative for patients refractory to first-line monotherapy. Exciting advances are ongoing in the research to improve the efficacy/tolerability profile of botulinum toxin, through innovative routes of administration. Several new agents emerged from preclinical studies, some of which have now entered the clinical phase of development and could represent, in the coming years, a new way for the treatment of UI. Recent evidence on the existence of different overactive bladder phenotypes could be the key to tailored treatment. Rather than discovering new molecules, reaching the ability to identify the right drug for the right patient could be the real gamechanger of the future.

Clinical Uses of a Robot (Hybrid-Assisted Limb or HAL™) in Patients with Post-stroke Spasticity after Botulinum Toxin Injections

Spasticity is the major cause of disabilities in stroke-survivors. Botulinum neurotoxin (BoNT) injections have been used to reduce the muscle tone in those patients, but its efficacy in functional outcome is not well delineated. We have studied the effect of a robot (Hybrid-Assisted Limb or HAL™) designed for assisting the elbow flexion and extension in those who underwent BoNT injections with reduced muscle tone. We enrolled 15 post stroke patients who had BoNT injections for more than 12 months. They were measured for active ROM (range of motion) with video recordings before and after the use of HAL for 40 minutes. Active ROM was measured by a rater who were blinded as to the use of the robot. Significant increase of active ROM was observed immediately after the use of HAL, and the effect was maintained for another 12 months by repeating the sessions. It is suggested from present study that the combined use of BoNT and robotics is effective efficacious for regaining the active function of the upper limb in stroke survivors. J. Med. Invest. 68 : 297-301, August, 2021.

Botulinum Neurotoxins in Central Nervous System: An Overview from Animal Models to Human Therapy

Botulinum neurotoxins (BoNTs) are potent inhibitors of synaptic vesicle fusion and transmitter release. The natural target of BoNTs is the peripheral neuromuscular junction (NMJ) where, by blocking the release of acetylcholine (ACh), they functionally denervate muscles and alter muscle tone. This leads them to be an excellent drug for the therapy of muscle hyperactivity disorders, such as dystonia, spasticity, and many other movement disorders. BoNTs are also effective in inhibiting both the release of ACh at sites other than NMJ and the release of neurotransmitters other than ACh. Furthermore, much evidence shows that BoNTs can act not only on the peripheral nervous system (PNS), but also on the central nervous system (CNS). Under this view, central changes may result either from sensory input from the PNS, from retrograde transport of BoNTs, or from direct injection of BoNTs into the CNS. The aim of this review is to give an update on available data, both from animal models or human studies, which suggest or confirm central alterations induced by peripheral or central BoNTs treatment. The data will be discussed with particular attention to the possible therapeutic applications to pathological conditions and degenerative diseases of the CNS.

Recombinant botulinum neurotoxin serotype A1 in vivo characterization

Clinically used botulinum neurotoxins (BoNTs) are natural products of Clostridium botulinum. A novel, recombinant BoNT type A1 (rBoNT/A1; IPN10260) has been synthesized using the native amino acid sequence expressed in Escherichia coli and has previously been characterized in vitro and ex vivo. Here, we aimed to characterize rBoNT/A1 in vivo and evaluate its effects on skeletal muscle. The properties of rBoNT/A1 following single, intramuscular administration were evaluated in the mouse and rat digit abduction score (DAS) assays and compared with those of natural BoNT/A1 (nBoNT/A1). rBoNT/A1-injected tibialis anterior was assessed in the in situ muscle force test in rats. rBoNT/A1-injected gastrocnemius lateralis (GL) muscle was assessed in the compound muscle action potential (CMAP) test in rats. The rBoNT/A1-injected GL muscle was evaluated for muscle weight, volume, myofiber composition and immunohistochemical detection of cleaved SNAP25 (c-SNAP25). Results showed that rBoNT/A1 and nBoNT/A1 were equipotent and had similar onset and duration of action in both mouse and rat DAS assays. rBoNT/A1 caused a dose-dependent inhibition of muscle force and a rapid long-lasting reduction in CMAP amplitude that lasted for at least 30 days. Dose-dependent reductions in GL weight and volume and increases in myofiber atrophy were accompanied by immunohistochemical detection of c-SNAP25. Overall, rBoNT/A1 and nBoNT/A1 exhibited similar properties following intramuscular administration. rBoNT/A1 inhibited motoneurons neurotransmitter release, which was robust, long-lasting, and accompanied by cleavage of SNAP25. rBoNT/A1 is a useful tool molecule for comparison with current natural and future modified recombinant neurotoxins products.

A Rabbit Model for the Evaluation of Drugs for Treating the Chronic Phase of Botulism

Antitoxin, the only licensed drug therapy for botulism, neutralizes circulating botulinum neurotoxin (BoNT). However, antitoxin is no longer effective when a critical amount of BoNT has already entered its target nerve cells. The outcome is a chronic phase of botulism that is characterized by prolonged paralysis. In this stage, blocking toxin activity within cells by next-generation intraneuronal anti-botulinum drugs (INABDs) may shorten the chronic phase of the disease and accelerate recovery. However, there is a lack of adequate animal models that simulate the chronic phase of botulism for evaluating the efficacy of INABDs. Herein, we report the development of a rabbit model for the chronic phase of botulism, induced by intoxication with a sublethal dose of BoNT. Spirometry monitoring enabled us to detect deviations from normal respiration and to quantitatively define the time to symptom onset and disease duration. A 0.85 rabbit intramuscular median lethal dose of BoNT/A elicited the most consistent and prolonged disease duration (mean = 11.8 days, relative standard deviation = 27.9%) that still enabled spontaneous recovery. Post-exposure treatment with antitoxin at various time points significantly shortened the disease duration, providing a proof of concept that the new model is adequate for evaluating novel therapeutics for botulism.

A Novel Running Wheel Mouse Model for Botulism and Its Use for the Evaluation of Postsymptom Antitoxin Efficacy

Antitoxin is currently the only approved therapy for botulinum intoxications. The efficacy of antitoxin preparations is evaluated in animals. However, while in practice antitoxin is administered to patients only after symptom onset, in most animal studies, it is tested in relation to time postintoxication. This may be attributed to difficulties in quantitating early botulism symptoms in animals. In the current study, a novel system based on high-resolution monitoring of mouse activity on a running wheel was developed to allow evaluation of postsymptom antitoxin efficacy. The system enables automatic and remote monitoring of 48 mice simultaneously. Based on the nocturnal activity patterns of individual naive mice, two criteria were defined as the onset of symptoms. Postsymptom treatment with a human-normalized dose of antitoxin was fully protective in mice exposed to 4 50% lethal doses (LD₅₀s) of botulinum neurotoxin serotype A (BoNT/A) and BoNT/B. Moreover, for the first time, a high protection rate was obtained in mice treated postsymptomatically, following a challenge with BoNT/E, the fastest-acting BoNT. The running wheel system was further modified to develop a mouse model for the evaluation of next-generation therapeutics for progressive botulism at time points where antitoxin is not effective. Exposure of mice to 0.3 LD₅₀ of BoNT/A resulted in long-lasting paralysis and a reduction in running activity for 16 to 18 days. Antitoxin treatment was no longer effective when administered 72 h postintoxication, defining the time window to evaluate next-generation therapeutics. Altogether, the running wheel systems presented herein offer quantitative means to evaluate the efficacy of current and future antibotulinum drugs.

Integration of Complete Plasmids Containing Bont Genes into Chromosomes of Clostridium parabotulinum, Clostridium sporogenes, and Clostridium argentinense

At least 40 toxin subtypes of botulinum neurotoxins (BoNTs), a heterogenous group of bacterial proteins, are produced by seven different clostridial species. A key factor that drives the diversity of neurotoxigenic clostridia is the association of bont gene clusters with various genomic locations including plasmids, phages and the chromosome. Analysis of Clostridium sporogenes BoNT/B1 strain CDC 1632, C. argentinense BoNT/G strain CDC 2741, and Clostridium parabotulinum BoNT/B1 strain DFPST0006 genomes revealed bont gene clusters within plasmid-like sequences within the chromosome or nested in large contigs, with no evidence of extrachromosomal elements. A nucleotide sequence (255,474 bp) identified in CDC 1632 shared 99.5% identity (88% coverage) with bont/B1-containing plasmid pNPD7 of C. sporogenes CDC 67071; CDC 2741 contig AYSO01000020 (1.1 MB) contained a ~140 kb region which shared 99.99% identity (100% coverage) with plasmid pRSJ17_1 of C. argentinense BoNT/G strain 89G; and DFPST0006 contig JACBDK0100002 (573 kb) contained a region that shared 100% identity (99%) coverage with the bont/B1-containing plasmid pCLD of C. parabotulinum Okra. This is the first report of full-length plasmid DNA-carrying complete neurotoxin gene clusters integrated in three distinct neurotoxigenic species: C. parabotulinum, C. sporogenes and C. argentinense.

Emergency response to a cluster of suspected food-borne botulism in Abuja, Nigeria: challenges with diagnosis and treatment in a resource-poor setting

Food-borne botulism is a rare, acute and potentially fatal neurologic disorder that results from ingestion of food contaminated by botulinum toxin released from the anaerobic, spore-forming, gram-positive bacterium Clostridium botulinum. We reported an unusual cluster of botulism outbreak with high case fatality affecting a family following ingestion of home-made fish. A suspected outbreak of botulism affecting three patients in a family of six was reported to the Nigeria Centre for Disease Control. A rapid response team investigated by line-listing all the family members, interviewed extended family members, caregivers, clinicians, and nurses to collect socio-demographic and clinico epidemiological information using a semi-structured questionnaires. We collected blood from patients and food samples and locally made drink from the family home for laboratory testing. All family members ingested the same home-made food within the 48hrs before onset of symptoms in the index case. The clinical presentation of the three affected cases (AR=50.0%) was consistent with botulinum poisoning. Two of the affected cases died (CFR=66.7%) within 48hrs of admission, before antitoxin was made available. The third case had a milder presentation and survived, after administration of appropriate antitoxin. The remaining three children developed no symptoms. None of the samples cultured Clostridium botulinum. The blood samples were negative for mouse lethality test. Our report describes the challenges of diagnosis and management of rare emerging infectious disease outbreaks in resource-constrained settings.

Reduction of self-mutilating behavior and improved oromotor function in a patient with Lesch-Nyhan syndrome following botulinum toxin injection: A case report

Lesch-Nyhan syndrome is a genetic metabolic disorder often involving dystonia and self-mutilating behavior. This case report describes a 13-year-old boy with Lesch-Nyhan syndrome and self-mutilating behavior who received botulinum toxin injections to his bilateral masseter muscles after failing multiple other treatments. Following injections, the patient had reduction in self-biting, along with improvements in speech, mastication and feeding observed in speech therapy. Botulinum toxin injections to the masseters may help to improve oromotor function and reduce self-mutilating behaviors in children with Lesch-Nyhan syndrome who have failed more conservative treatments, providing opportunity for improved functional status and patient safety. Further investigation is indicated to establish optimal dosing. Additionally, the mechanism for the reduction of self-mutilating behavior is unclear and justifies additional investigation.

Double-Binding Botulinum Molecule with Reduced Muscle Paralysis: Evaluation in In Vitro and In Vivo Models of Migraine

With a prevalence of 15%, migraine is the most common neurological disorder and among the most disabling diseases, taking into account years lived with disability. Current oral medications for migraine show variable effects and are frequently associated with intolerable side effects, leading to the dissatisfaction of both patients and doctors. Injectable therapeutics, which include calcitonin gene-related peptide-targeting monoclonal antibodies and botulinum neurotoxin A (BoNT/A), provide a new paradigm for treatment of chronic migraine but are effective only in approximately 50% of subjects. Here, we investigated a novel engineered botulinum molecule with markedly reduced muscle paralyzing properties which could be beneficial for the treatment of migraine. This stapled botulinum molecule with duplicated binding domain-binary toxin-AA (BiTox/AA)-cleaves synaptosomal-associated protein 25 with a similar efficacy to BoNT/A in neurons; however, the paralyzing effect of BiTox/AA was 100 times less when compared to native BoNT/A following muscle injection. The performance of BiTox/AA was evaluated in cellular and animal models of migraine. BiTox/AA inhibited electrical nerve fiber activity in rat meningeal preparations while, in the trigeminovascular model, BiTox/AA raised electrical and mechanical stimulation thresholds in Aδ- and C-fiber nociceptors. In the rat glyceryl trinitrate (GTN) model, BiTox/AA proved effective in inhibiting GTN-induced hyperalgesia in the orofacial formalin test. We conclude that the engineered botulinum molecule provides a useful prototype for designing advanced future therapeutics for an improved efficacy in the treatment of migraine.

Effect of treating elbow flexor spasticity with botulinum toxin injection and adjunctive casting on hemiparetic gait parameters: A prospective case series

OBJECTIVE

To investigate changes in hemiparetic gait parameters after treatment of elbow flexor spasticity with botulinum neurotoxin (BoNT) injection and adjunctive casting.

DESIGN

Prospective case series.

SUBJECTS

Ten participants with spasticity secondary to acquired brain injury (8 stroke, 2 traumatic brain injury).

INTERVENTIONS

Participants received BoNT injections for their spastic elbow flexors under ultrasound guid-ance. Two weeks post-injection, an elbow stretching cast was applied for 1 week.

OUTCOME MEASURES

Assessments using the Modified Ashworth Scale (MAS), Tardieu scale V1 angle of arrest at slow speed and V3 angle of catch at fast speed, 2-min walk test (2MWT), Edinburgh Gait Score scale (EGS) and video gait analysis for step-length symmetry were conducted pre-BoNT injection (t0) and at cast removal (t1). Goal attainment scale (GAS) was used to assess changes in spasticity and gait 3 months post-injection (t2).

RESULTS

At t1, participants showed a mean increase of 16.7° (p < 0.01) on the Tardieu Scale V3 and a mean reduction of 0.5 points on the MAS (p < 0.05). There was also a mean reduction on EGS of 2.7 points (p < 0.05), and a mean increase on 2MWT of 3.1 m (p < 0.05). On the GAS, all participants report-ed impro-ved gait at t2 and 80% reported a decrease in spasticity.

CONCLUSION

Combining BoNT injection with casting for treatment of elbow flexor spasticity without treat-ing the lower limb may improve hemiparetic gait parameters.

Mechanism of Action of OnabotulinumtoxinA in Chronic Migraine: A Narrative Review

Objective

To review the literature on the mechanism of action of onabotulinumtoxinA in chronic migraine.

Background

OnabotulinumtoxinA is a chronic migraine preventive treatment that significantly reduces headache frequency. The traditional mechanism described for onabotulinumtoxinA – reducing muscle contractions – is insufficient to explain its efficacy in migraine, which is primarily a sensory neurological disease.

Methods

A narrative literature review on the mechanism of action of onabotulinumtoxinA in chronic migraine.

Results

Following injection into tissues, onabotulinumtoxinA inhibits soluble N‐ethylmaleimide‐sensitive fusion attachment protein receptor (SNARE)‐mediated vesicle trafficking by cleaving one of its essential proteins, soluble N‐ethylmaleimide‐sensitive fusion attachment protein (SNAP‐25), which occurs in both motor and sensory nerves. OnabotulinumtoxinA inhibits regulated exocytosis of motor and sensory neurochemicals and proteins, as well as membrane insertion of peripheral receptors that convey pain from the periphery to the brain, because both processes are SNARE dependent. OnabotulinumtoxinA can decrease exocytosis of pro‐inflammatory and excitatory neurotransmitters and neuropeptides such as substance P, calcitonin gene‐related peptide, and glutamate from primary afferent fibers that transmit nociceptive pain and participate in the development of peripheral and central sensitization. OnabotulinumtoxinA also decreases the insertion of pain‐sensitive ion channels such as transient receptor potential cation channel subfamily V member 1 (TRPV1) into the membranes of nociceptive neurons; this is likely enhanced in the sensitized neuron. For chronic migraine prevention, onabotulinumtoxinA is injected into 31‐39 sites in 7 muscles of the head and neck. Sensory nerve endings of neurons whose cell bodies are located in trigeminal and cervical ganglia are distributed throughout the injected muscles, and are overactive in people with migraine. Through inhibition of these sensory nerve endings, onabotulinumtoxinA reduces the number of pain signals that reach the brain and consequently prevents activation and sensitization of central neurons postulated to be involved in migraine chronification.

Conclusion

OnabotulinumtoxinA likely acts via sensory mechanisms to treat chronic migraine.

Biosecurity Threat Posed by Botulinum Toxin

The deliberate release of biological agents with terrorist or criminal intent continues to pose concerns in the current geopolitical situation. Therefore, attention is still needed to ensure preparedness against the potential use of pathogens as unconventional weapons. Botulinum neurotoxin (BoNT) is one such biological threat, characterized by an extremely low lethal dose, high morbidity and mortality when appropriately disseminated, and the capacity to cause panic and social disruption. This paper addresses the risks of a potential release of the botulinum neurotoxin and summarizes the relevant aspects of the threat.

Rapid and Sensitive Nano-Immunosensors for Botulinum

Botulinum is a deadly bacterial toxin that causes neuroparalytic disease. However, appropriate tools to detect trace toxic proteins are scarce. This study presents a bead-based diffusometric technique for the rapid, simple, and quantitative detection of biological toxins. Functionalized particles called nano-immunosensors were fabricated by forming sandwiched immunocomplexes comprising Au nanoparticles (AuNPs), toxic proteins, and antibodies on fluorescent probe particles. Particle diffusivity tended to decline with increasing concentration of the target proteins. Calibration curves of purified botulinum toxins (0.01-500 ng/mL) were obtained from whole milk and bovine serum, and results suggested that measurement was independent of the background matrix. The activity of botulinum toxin was evaluated by coating synaptosomal-associated protein 25 (SNAP-25) on fluorescent probe particles. AuNP-conjugated antibodies attached to the probe particles when SNAP-25 proteins were cleaved by active botulinum. Thus, toxicity could be detected from slight changes in diffusivity. A short measurement time of 2 min and a limit of detection of 10 pg/mL were achieved. The nano-immunosensors demonstrated rapid biosensing capability and met the demands of onsite screening for food safety, medical instrument hygiene, and cosmetic surgery products.

Endoscopic botulinum toxin injection for treatment of pharyngeal dysphagia in patients with cricopharyngeal dysfunction

BACKGROUND

Dysphagia associated with neurologic disorders is a problem worldwide. However, few studies have assessed the efficacy of endoscopic botulinum toxin injections into the cricopharyngeal muscle using a pharyngoscope.

METHODS

Fourteen patients who received an endoscopic botulinum toxin injection due to cricopharyngeal muscle dysfunction and a neurological disorder from 2006 to 2017 were retrospectively reviewed at a single tertiary medical center. The toxin was injected at a 100 international unit (IU) total dose under direct endoscopic vision. The success of the procedure was evaluated comprehensively using the following: clinical resolution of the previous symptoms, functional oral intake scale (FOIS) for the clinical evaluation of swallowing, and videofluoroscopic swallowing study (VFSS) to check decreased retention of barium at the pyriform sinus and the epiglottic vallecula.

RESULTS

The study included 12 males and 2 females (mean age, 58 years old; range, 37-82 years). Three patients (21.4%) were confirmed clinically and eleven were confirmed by VFSS. Eleven patients (78.6%) were managed successfully with the injection. Three patients (21.4%) did not improve despite the injection.

CONCLUSION

An endoscopic botulinum toxin injection may be a good treatment option for patients with dysphagia and cricopharyngeal dysfunction due to a neurological disorder. Large, prospective, long-term follow-up studies are needed in the future.

Bridging therapy for achalasia in a second trimester pregnant patient

We present the case of a 28-year-old female who presented for primary care at 22-week gestation with type II achalasia and worsening solid/liquid dysphagia leading to pregnancy weight loss. Considering that durable therapies such as surgical myotomy and pneumatic dilatation have considerable risk, botulinum A toxin injection was selected as a temporizing bridging therapy. She had an uncomplicated post procedure course and had significant rapid improvement in dysphagia symptoms, which enabled her to progress to normal peripartum weight. This case highlights the need for early recognition of achalasia and an unique niche for use of botulinum toxin A as a temporizing therapy in this risk averse population.

[Spasticity: from pathophysiology to treatment]

The article presents modern views on the pathophysiology of spasticity, which is a frequent disabling consequence to the upper motor neuron (UMN) damage. Morphological and functional system of motion organization and the changes after the UMN damage is considered. The authors analyze existing definitions of spasticity. Stages of spasticity development are described in the context of neuroplasticity as well as in the framework of pathogenesis and sanogenesis. Existing ideas of its pathogenesis are compared with the typical clinical symptoms. The occurring pathological processes in muscles, tendons and joints that can aggravate the development of spasticity and complicate the diagnosis are considered. In addition, the main pathological spasticity patterns are described and the current development of diagnostic techniques is estimated. A review of main methods of spasticity treatment is presented. Special attention is paid to the botulinum neurotoxin type A (BoNT) preparations and central action muscle relaxants. The pathophysiological basement for complex treatment of spasticity as a part of the general rehabilitation process is given, so that the BoNT can be considered as the obligatory element of standard rehabilitation programs.

A Novel Rabbit Spirometry Model of Type E Botulism and Its Use for the Evaluation of Postsymptom Antitoxin Efficacy

Botulinum neurotoxins (BoNTs), the most poisonous substances known in nature, pose significant concern to health authorities. The only approved therapeutic for botulism is antitoxin. While administered to patients only after symptom onset, antitoxin efficacy is evaluated in animals mostly in relation to time postintoxication regardless of symptoms. This is most likely due to the difficulty in measuring early symptoms of botulism in animals. In this study, a rabbit spirometry model was developed to quantify early respiratory symptoms of type E botulism that were further used as a trigger for treatment. Impaired respiration, in the form of a reduced minute volume, was detected as early as 18.1 ± 2.9 h after intramuscular exposure to 2 rabbit 50% lethal doses (LD₅₀) of BoNT serotype E (BoNT/E), preceding any visible symptoms. All rabbits treated with antitoxin immediately following symptom onset survived. Postsymptom antitoxin efficacy was further evaluated in relation to toxin and antitoxin dosages as well as delayed antitoxin administration. Our system enabled us to demonstrate, for the first time, full antitoxin protection of animals treated with antitoxin after the onset of objective and quantitative type E botulism symptoms. This model may be utilized to evaluate the efficacy of antitoxins for additional serotypes of BoNT as well as that of next-generation anti-BoNT drugs that enter affected cells and act when antitoxin is no longer effective.

Decreasing pediatric pain and agitation during botulinum toxin injections for spasticity with virtual reality: Lessons learned from clinical use

PURPOSE

Recurrent botulinum toxin (BoNT) injections are used in the pediatric population for management of spasticity, but the procedure is often associated with significant pain and anxiety for patients. Non-pharmacologic treatment alternatives for procedural discomfort are limited. Immersive virtual reality (VR) has shown efficacy in treatment of procedural discomfort in pediatric patients. A retrospective chart review was performed to assess feasibility and use of treating BoNT procedure-related discomfort in pediatric patients with VR.

METHODS

Fourteen patients undergoing elective BoNT injections viewed VR videos using a mobile VR headset during the procedure. Face, Legs, Activity, Cry, Consolability scale (FLACC) scores were obtained and feedback was elicited following injections.

RESULTS

The VR intervention was well tolerated, and patients' guardians requested that it be used again in 9/14 cases. The remainder either had high FLACC scores despite VR and neutral or negative guardian impressions of intervention, or were unable to utilize the device.

CONCLUSION

VR was helpful in reducing BoNT procedure-related discomfort in a majority of patients. Challenges with VR setup, patient tolerance, and selecting viewing experiences were identified to guide further research and use of VR in a clinical environment.

Botulinum neurotoxin type C protease induces apoptosis in differentiated human neuroblastoma cells

Neuroblastomas constitute a major cause of cancer-related deaths in young children. In recent years, a number of translation-inhibiting enzymes have been evaluated for killing neuroblastoma cells. Here we investigated the potential vulnerability of human neuroblastoma cells to protease activity derived from botulinum neurotoxin type C. We show that following retinoic acid treatment, human neuroblastoma cells, SiMa and SH-SY5Y, acquire a neuronal phenotype evidenced by axonal growth and expression of neuronal markers. Botulinum neurotoxin type C which cleaves neuron-specific SNAP25 and syntaxin1 caused apoptotic death only in differentiated neuroblastoma cells. Direct comparison of translation-inhibiting enzymes and the type C botulinum protease revealed one order higher cytotoxic potency of the latter suggesting a novel neuroblastoma-targeting pathway. Our mechanistic insights revealed that loss of ubiquitous SNAP23 due to differentiation coupled to SNAP25 cleavage due to botulinum activity may underlie the apoptotic death of human neuroblastoma cells.

The European AntibotABE Framework Program and Its Update: Development of Innovative Botulinum Antibodies

The goal of the AntiBotABE Program was the development of recombinant antibodies that neutralize botulinum neurotoxins (BoNT) A, B and E. These serotypes are lethal and responsible for most human botulinum cases. To improve therapeutic efficacy, the heavy and light chains (HC and LC) of the three BoNT serotypes were targeted to achieve a synergistic effect (oligoclonal antibodies). For antibody isolation, macaques were immunized with the recombinant and non-toxic BoNT/A, B or E, HC or LC, followed by the generation of immune phage-display libraries. Antibodies were selected from these libraries against the holotoxin and further analyzed in in vitro and ex vivo assays. For each library, the best ex vivo neutralizing antibody fragments were germline-humanized and expressed as immunoglobulin G (IgGs). The IgGs were tested in vivo, in a standardized model of protection, and challenged with toxins obtained from collections of Clostridium strains. Protective antibody combinations against BoNT/A and BoNT/B were evidenced and for BoNT/E, the anti-LC antibody alone was found highly protective. The combination of these five antibodies as an oligoclonal antibody cocktail can be clinically and regulatorily developed while their high “humanness” predicts a high tolerance in humans.

A Novel Surface Plasmon Resonance Biosensor for the Rapid Detection of Botulinum Neurotoxins

Botulinum neurotoxins (BoNTs) are Category A agents on the NIAID (National Institute of Allergy and Infectious Diseases) priority pathogen list owing to their extreme toxicity and the relative ease of production. These deadly toxins, in minute quantities (estimated human i.v. lethal dose LD₅₀ of 1-2 ng/kg body weight), cause fatal flaccid paralysis by blocking neurotransmitter release. The current gold standard detection method, the mouse-bioassay, often takes days to confirm botulism. Furthermore, there are no effective antidotes known to reverse the symptoms of botulism, and as a result, patients with severe botulism often require meticulous care during the prolonged paralytic illness. To combat potential bio-terrorism incidents of botulinum neurotoxins, their rapid detection is paramount. Surface plasmon resonance (SPR) is a very sensitive technique to examine bio-molecular interactions. The label-free, real-time analysis, with high sensitivity and low sample consumption makes this technology particularly suitable for detection of the toxin. In this study, we demonstrated the feasibility in an assay with a newly designed SPR instrument for the rapid detection of botulinum neurotoxins. The LOD (limit of detection) of the Newton Photonics (NP) SPR based assay is 6.76 pg/mL for Botulinum Neurotoxin type A Light Chain (BoNT/A LC). We established that the detection sensitivity of the system is comparable to the traditional mouse LD₅₀ bioassay in BoNT/A using this SPR technology.

Role of Homologous Fc Fragment in the Potency and Efficacy of Anti-Botulinum Antibody Preparations

The only approved treatment for botulism relies on passive immunity which is mostly based on antibody preparations collected from hyper-immune horses. The IgG Fc fragment is commonly removed from these heterologous preparations to reduce the incidence of hyper-sensitivity reactions. New-generation therapies entering the pipeline are based on a combination of humanized monoclonal antibodies (MAbs), which exhibit improved safety and pharmacokinetics. In the current study, a systematic and quantitative approach was applied to measure the direct contribution of homologous Fc to the potency of monoclonal and polyclonal antitoxin preparations in mice. Homologous Fc increased the potency of three individual anti-botulinum toxin MAbs by up to one order of magnitude. Moreover, Fc fragment removal almost completely abolished the synergistic potency obtained from a combined preparation of these three MAbs. The MAb mixture neutralized a 400-mouse median lethal dose (MsLD₅₀) of botulinum toxin, whereas the F(ab′)₂ combination failed to neutralize 10 MsLD₅₀ of botulinum toxin. Notably, increased avidity did not compensate for this phenomenon, as a polyclonal, hyper-immune, homologous preparation lost 90% of its potency as well upon Fc removal. Finally, the addition of homologous Fc arms to a heterologous pharmaceutical anti-botulinum toxin polyclonal horse F(ab′)₂ preparation improved its efficacy when administered to intoxicated symptomatic mice. Our study extends the aspects by which switching from animal-based to human-based antitoxins will improve not only the safety but also the potency and efficacy of passive immunity against toxins.

Electrophysiologically identified piriformis syndrome is successfully treated with incobotulinum toxin a and physical therapy

INTRODUCTION

Piriformis syndrome is entrapment of the sciatic nerve by the piriformis muscle.

METHODS

In this article we describe a 56-person randomized, double-blind, controlled study involving physical therapy and incobotulinum toxin A or placebo. Inclusion criteria were 3-SD delay of posterior tibial (PT) or fibular (FN) H-reflexes on flexion, adduction, and internal rotation (FAIR) testing, and normal paraspinal electromyographic findings. Outcome measures included adverse side effects, visual analog scale (VAS) findings, and H-reflex delay on the FAIR test.

RESULTS

Mean intervention VAS score decreased significantly more compared with placebo at 2, 4, 6, 8, 10, and 12 weeks post-injection (P < 0.0001). FAIR test scores for PT, but not FN, decreased significantly more compared with placebo at 2, 4, 6, and 8 weeks post-injection (PT: P = 0.038, 0.003, 0.003, and 0.046). Adverse effects were minimal. VAS slope and PT FAIR test results varied significantly (P < 0.0001).

CONCLUSION

Incobotulinum toxin A chemodenervation may be useful for treating piriformis syndrome as identified by the FAIR test. Muscle Nerve 56: 258-263, 2017.

Historical Perspectives and Guidelines for Botulinum Neurotoxin Subtype Nomenclature

Botulinum neurotoxins are diverse proteins. They are currently represented by at least seven serotypes and more than 40 subtypes. New clostridial strains that produce novel neurotoxin variants are being identified with increasing frequency, which presents challenges when organizing the nomenclature surrounding these neurotoxins. Worldwide, researchers are faced with the possibility that toxins having identical sequences may be given different designations or novel toxins having unique sequences may be given the same designations on publication. In order to minimize these problems, an ad hoc committee consisting of over 20 researchers in the field of botulinum neurotoxin research was convened to discuss the clarification of the issues involved in botulinum neurotoxin nomenclature. This publication presents a historical overview of the issues and provides guidelines for botulinum neurotoxin subtype nomenclature in the future.

Development of an Innovative in Vitro Potency Assay for Anti-Botulinum Antitoxins

Botulinum neurotoxins are bacterial proteins that cause botulism, a life-threatening disease. Therapy relies mostly on post-intoxication antibody treatment. The only accepted method to measure the potency of, and to approve, antitoxin preparations is the mouse lethality neutralization bioassay. However, this assay is time-consuming, labor-intensive, costly, and raises ethical issues related to the large numbers of laboratory animals needed. Until now, all efforts to develop an alternative in vitro assay have not provided a valid replacement to the mouse potency assay. In the present study, we report the development of an innovative in vitro assay for determining botulinum antitoxin potency, using botulinum type B as a model. The concept of the assay is to mimic two fundamental steps in botulinum intoxication: receptor binding and catalytic activity. By simulating these steps in vitro we were able to accurately determine the potency of antitoxin preparations. The reproducibility of the assay was high with a CV < 13%. Most importantly, the antitoxin potency measured by the in vitro assay highly correlated with that measured by the standard in vivo mouse assay (r = 0.9842, p < 0.0001). Thus, this new in vitro assay has the potential to be considered, after validation, as a replacement to the mouse assay for quantitating neutralizing antibody concentrations in pharmaceutical botulinum antitoxin preparations. Future adoption of this in vitro assay would minimize the use of laboratory animals, speed up the time, and reduce the cost of botulinum antitoxin approval.

Outbreak of Botulism After Consumption of Illicit Prison-Brewed Alcohol in a Maximum Security Prison--Arizona, 2012

The authors investigated the second botulism outbreak to occur in a maximum security prison in Arizona within a 4-month period. Botulism was confirmed in eight men aged 20 to 35 years who reported sharing a single batch of pruno made with potatoes. Initial symptoms included blurred vision, slurred speech, muscle weakness, ptosis, and dysphagia. All patients received heptavalent botulinum antitoxin, seven required mechanical ventilation, and all survived. The median incubation period was 29 hours. Sera from all patients and leftover pruno tested positive for botulinum toxin type A. Botulism should be considered among prisoners with cranial nerve palsies and descending, symmetric flaccid paralysis. Prison-brewed alcohol, particularly when made with potatoes, can be a vehicle for botulism and is associated with outbreaks of botulism in prisons.

Vasculitis with panniculitis following botulinum toxin A injection for cosmetic use

Botulinum toxin A injection is performed most frequently for facial rejuvenation all over the world. Some bizarre and severe side effects have been reported after botulinum toxin A injection. Herein, we present a case of vasculitis with panniculitis after a patient underwent a cosmetic procedure that included injection of purported botulinum toxin A.