Presynaptic targeting of botulinum neurotoxin type A requires a tripartite PSG-Syt1-SV2 plasma membrane nanocluster for synaptic vesicle entry.

The unique nerve terminal targeting of botulinum neurotoxin type A (BoNT/A) is due to its capacity to bind two receptors on the neuronal plasma membrane: polysialoganglioside (PSG) and synaptic vesicle glycoprotein 2 (SV2). Whether and how PSGs and SV2 may coordinate other proteins for BoNT/A recruitment and internalization remains unknown. Here, we demonstrate that the targeted endocytosis of BoNT/A into synaptic vesicles (SVs) requires a tripartite surface nanocluster. Live-cell super-resolution imaging and electron microscopy of catalytically inactivated BoNT/A wildtype and receptor-binding-deficient mutants in cultured hippocampal neurons demonstrated that BoNT/A must bind coincidentally to a PSG and SV2 to target synaptic vesicles. We reveal that BoNT/A simultaneously interacts with a preassembled PSG-synaptotagmin-1 (Syt1) complex and SV2 on the neuronal plasma membrane, facilitating Syt1-SV2 nanoclustering that controls endocytic sorting of the toxin into synaptic vesicles. Syt1 CRISPRi knockdown suppressed BoNT/A- and BoNT/E-induced neurointoxication as quantified by SNAP-25 cleavage, suggesting that this tripartite nanocluster may be a unifying entry point for selected botulinum neurotoxins that hijack this for synaptic vesicle targeting.

Neutralizing chimeric heavy-chain antibody targeting the L-HN domain of Clostridium botulinum neurotoxin type F.

Botulinum toxin (BoNT) from Clostridium botulinum is the most toxic biotoxin known and is also an important bioterrorism agent. After poisoning, the only effective treatment is injection of antitoxin. However, neutralizing nanoantibodies are safer and more effective, representing a promising therapeutic approach. Therefore, it is important to obtain effective neutralizing nanoantibodies. Hence, the present study aimed to construct a phage antibody library by immunizing a camel and screening specific clones that bind to the L-HN domain of BoNT/F and constructing chimeric heavy-chain antibodies by fusing them with a human Fc fragment. The antibodies' affinity and in vivo neutralizing activities were evaluated. The results showed that 2 µg of F20 antibody could completely neutralize 20 × the median lethal dose (LD50) of BoNT/F in vitro. Injection of 5 mg/kg F20 at 1 h, 2 h, 3 h, and 4 h into mice after BoNT/F challenge resulted in complete survival in vivo. Overall, the antibody might be a candidate for the development of new drugs to treat botulism.

Potency Evaluations of Recombinant Botulinum Neurotoxin A1 Mutants Designed to Reduce Toxicity.

Recombinant mutant holotoxin BoNTs (rBoNTs) are being evaluated as possible vaccines against botulism. Previously, several rBoNTs containing 2-3 amino acid mutations in the light chain (LC) showed significant decreases in toxicity (2.5-million-fold-12.5-million-fold) versus wild-type BoNT/A1, leading to their current exclusion from the Federal Select Agent list. In this study, we added four additional mutations in the receptor-binding domain, translocation domain, and enzymatic cleft to further decrease toxicity, creating 7M rBoNT/A1. Due to poor expression in E. coli, 7M rBoNT/A1 was produced in an endogenous C. botulinum expression system. This protein had higher residual toxicity (LD50: 280 ng/mouse) than previously reported for the catalytically inactive rBoNT/A1 containing only three of the mutations (>10 µg/mouse). To investigate this discrepancy, several additional rBoNT/A1 constructs containing individual sets of amino acid substitutions from 7M rBoNT/A1 and related mutations were also endogenously produced. Similarly to endogenously produced 7M rBoNT/A1, all of the endogenously produced mutants had ~100-1000-fold greater toxicity than what was reported for their original heterologous host counterparts. A combination of mutations in multiple functional domains resulted in a greater but not multiplicative reduction in toxicity. This report demonstrates the impact of production systems on residual toxicity of genetically inactivated rBoNTs.

Critical analysis in the advancement of cell-based assays for botulinum neurotoxin.

The study on botulinum neurotoxins (BoNTs) has rapidly evolved for their structure and functions as opposed to them being poisons or cures. Since their discoveries, the scientific community has come a long way in understanding BoNTs' structure and biological activity. Given its current application as a tool for understanding neurocellular activity and as a drug against over 800 neurological disorders, relevant and sensitive assays have become critical for biochemical, physiological, and pharmacological studies. The natural entry of the toxin being ingestion, it has also become important to examine its mechanism while crossing the epithelial cell barrier. Several techniques and methodologies have been developed, for its entry, pharmacokinetics, and biological activity for identification, and drug efficacy both in vivo and in vitro conditions. However, each of them presents its own challenges. The cell-based assay is a platform that exceeds the sensitivity of mouse bioassay while encompassing all the steps of intoxication including cell binding, transcytosis, endocytosis, translocation and proteolytic activity. In this article we review in detail both the neuronal and nonneuronal based cellular interaction of BoNT involving its transportation, and interaction with the targeted cells, and intracellular activities.

Analgesic Effect of Perineural Injection of BoNT/A on Neuropathic Pain Induced by Chronic Constriction Injury of Sciatic Nerve in Rats.

This study was designed to investigate the analgesic effect of perineural injection of BoNT/A on neuropathic pain induced by sciatic nerve chronic constriction injury (CCI) and possible mechanisms. SD rats were randomly divided into Sham group, CCI group and BoNT/A group. Paw mechanical withdrawal threshold (pMWT) and paw thermal withdrawal latency (pTWL) of each group were detected at different time points after surgery. The expression of myelin markers, autophagy markers and NLRP3 inflammasome-related molecules in injured sciatic nerves were examined at 12 days after surgery. Moreover, C-fiber evoked potential in spinal dorsal horn was recorded. The expression of SNAP-25, neuroinflammation and synaptic plasticity in spinal dorsal horn of each group were examined. Then rats treated with BoNT/A were randomly divided into DMSO group and Wnt agonist group to further explore the regulatory effect of BoNT/A on Wnt pathway. We found that pMWT and pTWL of ipsilateral paw were significantly decreased in CCI group compared with Sham group, which could be improved by perineural injection of BoNT/A at days 7, 9 and 12 after surgery. The peripheral analgesic mechanisms of perineural injection of BoNT/A might be related to the protective effect on myelin sheath by inhibiting NLRP3 inflammasome and promoting autophagy flow, while the central analgesic mechanisms might be associated with inhibition of neuroinflammation and synaptic plasticity in spinal dorsal horn due to inhibiting SNAP-25 and Wnt pathway. As a new route of administration, perineural injection of BoNT/A can relieve CCI induced neuropathic pain probably via both peripheral and central analgesic mechanisms.

Tetanus toxin and botulinum neurotoxin-derived fusion molecules are effective bivalent vaccines.

Tetanus toxin (TeNT) and botulinum neurotoxins (BoNTs) are neuroprotein toxins, with the latter being the most toxic known protein. They are structurally similar and contain three functional domains: an N-terminal catalytic domain (light chain), an internal heavy-chain translocation domain (HN domain), and a C-terminal heavy chain receptor binding domain (Hc domain or RBD). In this study, fusion functional domain molecules consisting of the TeNT RBD (THc) and the BoNT/A RBD (AHc) (i.e., THc-Linker-AHc and AHc-Linker-THc) were designed, prepared, and identified. The interaction of each Hc domain and the ganglioside receptor (GT1b) or the receptor synaptic vesicle glycoprotein 2 (SV2) was explored in vitro. Their immune response characteristics and protective efficacy were investigated in animal models. The recombinant THc-linker-AHc and AHc-linker-THc proteins with the binding activity had the correct size and structure, thus representing novel subunit vaccines. THc-linker-AHc and AHc-linker-THc induced high levels of specific neutralizing antibodies, and showed strong immune protective efficacy against both toxins. The high antibody titers against the two novel fusion domain molecules and against individual THc and AHc suggested that the THc and AHc domains, as antigens in the fusion functional domain molecules, do not interact with each other and retain their full key epitopes responsible for inducing neutralizing antibodies. Thus, the recombinant THc-linker-AHc and AHc-linker-THc molecules are strong and effective bivalent biotoxin vaccines, protecting against two biotoxins simultaneously. Our experimental design will be valuable to develop recombinant double-RBD fusion molecules as potent bivalent subunit vaccines against bio-toxins. KEY POINTS: • Double-RBD fusion molecules from two toxins had the correct structure and activity. • THc-linker-AHc and AHc-linker-THc efficiently protected against both biotoxins. • Such bivalent biotoxin vaccines based on the RBD are a valuable experimental design.

Daily Vibrotactile Stimulation Exhibits Equal or Greater Spasticity Relief Than Botulinum Toxin in Stroke.

OBJECTIVE: To test the feasibility and efficacy of the VibroTactile Stimulation (VTS) Glove, a wearable device that provides VTS to the impaired limb to reduce spastic hypertonia. DESIGN: Prospective 2-arm intervention study-including 1 group of patients who use Botulinum toxin (BTX-A) for spasticity and 1 group of patients who do not use BTX-A. SETTING: Participants were recruited through rehabilitation and neurology clinics. PARTICIPANTS: Patients with chronic stroke (N=20; mean age=54 years, mean time since stroke=6.9 years). Patients who were previously receiving the standard of care (BTX-A injection) were eligible to participate and started the intervention 12 weeks after their last injection. INTERVENTION: Participants were instructed to use the VTS Glove for 3 hours daily, at home or during everyday activities, for 8 weeks. MAIN OUTCOME MEASURES: Spasticity was assessed with the Modified Ashworth Scale and the Modified Tardieu Scale at baseline and then at 2-week intervals for 12 weeks. Primary outcomes were the difference from baseline and at week 8 (end of VTS Glove use) and week 12 (4 weeks after stopping VTS Glove use). Patients who were receiving BTX-A were also assessed during the 12 weeks preceding the start of VTS Glove use to monitor the effect of BTX-A on spastic hypertonia. Range of motion and participant feedback were also studied. RESULTS: A clinically meaningful difference in spastic hypertonia was found during and after daily VTS Glove use. Modified Ashworth and Modified Tardieu scores were reduced by an average of 0.9 (P=.0014) and 0.7 (P=.0003), respectively, at week 8 of daily VTS Glove use, and by 1.1 (P=.00025) and 0.9 (P=.0001), respectively, 1 month after stopping VTS Glove use. For participants who used BTX-A, 6 out of 11 showed greater change in Modified Ashworth ratings during VTS Glove use (mean=-1.8 vs mean=-1.6 with BTX-A) and 8 out of 11 showed their lowest level of symptoms during VTS Glove use (vs BTX-A). CONCLUSIONS: Daily stimulation from the VTS Glove provides relief of spasticity and hypertonia. For more than half of the participants who had regularly used BTX-A, the VTS Glove provided equal or greater symptom relief.

Examining the role of intrinsic and reflexive contributions to ankle joint hyper-resistance treated with botulinum toxin-A.

BACKGROUND: Spasticity, i.e. stretch hyperreflexia, increases joint resistance similar to symptoms like hypertonia and contractures. Botulinum neurotoxin-A (BoNT-A) injections are a widely used intervention to reduce spasticity. BoNT-A effects on spasticity are poorly understood, because clinical measures, e.g. modified Ashworth scale (MAS), cannot differentiate between the symptoms affecting joint resistance. This paper distinguishes the contributions of the reflexive and intrinsic pathways to ankle joint hyper-resistance for participants treated with BoNT-A injections. We hypothesized that the overall joint resistance and reflexive contribution decrease 6 weeks after injection, while returning close to baseline after 12 weeks. METHODS: Nine participants with spasticity after spinal cord injury or after stroke were evaluated across three sessions: 0, 6 and 12 weeks after BoNT-A injection in the calf muscles. Evaluation included clinical measures (MAS, Tardieu Scale) and motorized instrumented assessment using the instrumented spasticity test (SPAT) and parallel-cascade (PC) system identification. Assessments included measures for: (1) overall resistance from MAS and fast velocity SPAT; (2) reflexive resistance contribution from Tardieu Scale, difference between fast and slow velocity SPAT and PC reflexive gain; and (3) intrinsic resistance contribution from slow velocity SPAT and PC intrinsic stiffness/damping. RESULTS: Individually, the hypothesized BoNT-A effect, the combination of a reduced resistance (week 6) and return towards baseline (week 12), was observed in the MAS (5 participants), fast velocity SPAT (2 participants), Tardieu Scale (2 participants), SPAT (1 participant) and reflexive gain (4 participants). On group-level, the hypothesis was only confirmed for the MAS, which showed a significant resistance reduction at week 6. All instrumented measures were strongly correlated when quantifying the same resistance contribution. CONCLUSION: At group-level, the expected joint resistance reduction due to BoNT-A injections was only observed in the MAS (overall resistance). This observed reduction could not be attributed to an unambiguous group-level reduction of the reflexive resistance contribution, as no instrumented measure confirmed the hypothesis. Validity of the instrumented measures was supported through a strong association between different assessment methods. Therefore, further quantification of the individual contributions to joint resistance changes using instrumented measures across a large sample size are essential to understand the heterogeneous response to BoNT-A injections.

Efficacy and Safety of Botulinum Toxin Type A for Treatment of Glabellar Lines: A Network Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Botulinum toxin type A (BoNT/A) has been used in aesthetic applications worldwide, including glabellar lines. Currently, four BoNT/A preparations were approved for the improvement of moderate-to-severe glabellar lines: onabotulinumtoxinA, abobotulinumtoxinA, incobotulinumtoxinA, and prabotulinumtoxinA. DaxibotulinumtoxinA is a new form of BoNT/A drug that is developed in clinical application. We performed this network meta-analysis (NMA) to assess the efficacy and safety of all these different BoNT/A formulations for treating glabellar lines. METHODS: The investigators searched randomized controlled trials (RCTs) using the Medical Subject Headings (MeSH) terms "botulinum toxin" and "glabellar lines." We searched the relevant studies in electronic databases as following: PubMed, Elsevier, EMBASE and the Cochrane Library. The end points included the percentage of subjects with a glabellar line severity (GLS) score of none (0) or mild (1), and the percentage of subjects achieving ≥ 1-point and 2-point improvement in glabellar line severity at maximum frown at approximately month 1 by the investigators' assessment. RESULTS: All formulations of BoNT/A were far superior to placebo in efficacy. DaxibotulinumtoxinA was the only treatment that significantly increased the proportion of subjects achieving ≥ 1 point improvement in GLS score compared with other BoNT/A formulations. Moreover, daxibotulinumtoxinA was ranked the highest for the proportion of subjects achieving ≥ 2-point improvement in GLS score. No significant differences were revealed for the incidence of any adverse events (AEs) that related to treatment or drug among all BoNT/A preparations. CONCLUSION: The overall results of this NMA suggested that daxibotulinumtoxinA is a new BoNT/A preparation that may be not only more effective but also well-tolerated for the treatment of glabellar lines. LEVEL OF EVIDENCE I: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Botulinum Neurotoxin A4 Has a 1000-Fold Reduced Potency Due to Three Single Amino Acid Alterations in the Protein Receptor Binding Domain.

Botulinum neurotoxin subtype A4 (BoNT/A4) is ~1000-fold less potent than BoNT/A1. This study addresses the basis for low BoNT/A4 potency. Utilizing BoNT/A1-A4 and BoNT/A4-A1 Light Chain-Heavy Chain (LC-HC) chimeras, HC-A4 was responsible for low BoNT/A4 potency. Earlier studies showed BoNT/A1-receptor binding domain (Hcc) bound a ß-strand peptide (556-564) and glycan-N559 within Luminal Domain 4 (LD4) of SV2C, the BoNT/A protein receptor. Relative to BoNT/A1, the Hcc of BoNT/A4 possesses two amino acid variants (D1141 and N1142) within the ß-peptide binding interface and one amino acid variant (R1292) located near the SV2C glycan-N559. Introduction of BoNT/A4 ß-strand peptide variant (D1141 and N1142) into BoNT/A1 reduced toxin potency 30-fold, and additional introduction of the BoNT/A4 glycan-N559 variant (D1141, N1142, and R1292) further reduced toxin potency to approach BoNT/A4. While introduction of BoNT/A1 glycan-N559 variant (G1292) into BoNT/A4 did not alter toxin potency, additional introduction of BoNT/A1 ß-strand peptide variants (G1141, S1142, and G1292) resulted in potency approaching BoNT/A1 potency. Thus, outcomes from these functional and modeling studies indicate that in rodent models, disruption of Hcc -SV2C ß-peptide and -glycan-N559 interactions mediate low BoNT/A4 potency, while in human motor neurons, disruption of Hcc-SV2C ß-peptide alone mediates low BoNT/A4 potency, which link to a species-specific variation at SV2C563.

Width of the orbicularis oculi fibers extending to the upper lip with the lateral and inferior lengths of the orbicularis oculi at the lateral canthus level: application to botulinum neurotoxin type A injection for crow's feet.

PURPOSE: The aim of this study was to determine the width of the fibers that extend from the orbicularis oculi muscle (OOc) to the upper lip, and the lateral and inferior lengths of the OOc at the lateral canthus level. METHODS: The OOc was investigated in the 40 hemifaces of 20 Korean cadavers. The lateral fibers of the OOc (OOc lat) were traced to determine whether or not these fibers extended to the upper lip. RESULTS: The OOc lat extended to the upper lip at the lateral canthus level in 31 of the 40 specimens (77.5%), whereas some inferolateral fibers of the OOc that extended to the upper lip were observed near the level of the lower margin of the OOc in the other 9 specimens (22.5%). The mean ± SD and maximum widths of the OOc lat that extended to the upper lip at the lateral canthus level were 6.9 ± 3.3 mm and 14.3 mm, respectively. CONCLUSION: The obtained data will be helpful to distinguish the muscles that underly the wrinkles around the lateral canthus for safer and more-efficient BoNT-A treatments for crow's feet.

BoNT-A efficacy in high frequency migraine: an open label, single arm, exploratory study applying the PREEMPT paradigm.

INTRODUCTION: In this open label, single-arm trial we evaluated the efficacy of onabotulinum toxin-A in the prevention of high-frequency episodic migraine (8-14 migraine days/month). METHODS: We enrolled 32 high-frequency episodic migraine subjects (age 44.8 ± 11.9 years, 11.0 ± 2.2 migraine days, 11.5 ± 2.1 headache days, 7 females). After a 28-day baseline period, subjects underwent 4 subsequent onabotulinum toxin-A treatments according to the phase III research evaluating migraine prophylaxis therapy (PREEMPT) paradigm, 12-weeks apart. The primary outcome was the reduction of monthly migraine days from baseline in the 12-week period following the last onabotulinum toxin-A treatment. RESULTS: Onabotulinum toxin-A reduced monthly migraine days by 3.68 days (-33.1%, p < 0.01). Thirty-nine percent of the patients experienced a ≥50% reduction in monthly migraine days. Onabotulinum toxin-A also reduced the number of headache days (-33.9%, p < 0.01) and the intake of acute medications (-22.9%, p = 0.03). Disability and quality of life (QoL) scores improved markedly (migraine disability assessment (MIDAS) -41.7%; migraine specific questionnaire (MSQ) -31.7%, p < 0.01). CONCLUSIONS: The findings suggest that, when administered according to the PREEMPT paradigm, onabotulinum toxin-A is effective in the prevention of high-frequency episodic migraine.Trial Registration: NCT04578782.

Predicting outcomes after intradetrusor onabotulinumtoxina for non-neurogenic urgency incontinence in women.

AIMS: Develop models to predict outcomes after intradetrusor injection of 100 or 200 units of onabotulinumtoxinA in women with non-neurogenic urgency urinary incontinence (UUI). METHODS: Models were developed using 307 women from two randomized trials assessing efficacy of onabotulinumtoxinA for non-neurogenic UUI. Cox, linear and logistic regression models were fit using: (1) time to recurrence over 12 months, (2) change from baseline daily UUI episodes (UUIE) at 6 months, and (3) need for self-catheterization over 6 months. Model discrimination of Cox and logistic regression models was calculated using c-index. Mean absolute error determined accuracy of the linear model. Calibration was demonstrated using calibration curves. All models were internally validated using bootstrapping. RESULTS: Median time to recurrence was 6 (interquartile range [IQR]: 2-12) months. Increasing age, 200 units of onabotulinumtoxinA, higher body mass index (BMI) and baseline UUIE were associated with decreased time to recurrence. The c-index was 0.63 (95% confidence interval [CI]: 0.59, 0.67). Median change in daily UUIE from baseline at 6 months was -3.5 (IQR: -5.0, -2.3). Increasing age, lower baseline UUIE, 200 units of onabotulinumtoxinA, higher BMI and IIQ-SF were associated with less improvement in UUIE. The mean absolute error predicting change in UUIE was accurate to 1.6 (95% CI: 1.5, 1.7) UUI episodes. The overall rate of self-catheterization was 17.6% (95% CI: 13.6%-22.4%). Lower BMI, 200 units of onabotulinumtoxinA, increased baseline postvoid residual and maximum capacity were associated with higher risk of self-catheterization. The c-index was 0.66 (95% CI: 0.61, 0.76). The three calculators are available at http://riskcalc.duke.edu. CONCLUSIONS: After external validation, these models will assist clinicians in providing more accurate estimates of expected treatment outcomes after onabotulinumtoxinA for non-neurogenic UUI in women.

Botulinum toxin in cancer therapy-current perspectives and limitations.

Different serotypes of botulinum toxins (BoNTs) act upon different types of SNARE proteins. This property is used in aesthetic medicine to treat certain eye disorders such as crossed eyes (strabismus) and uncontrolled blinking (blepharospasm), to treat muscle spasms or movement disorders, and, for the two last decades, more and more often, to provide support in cancer therapy, especially so as to obtain analgesic effects upon spastic conditions. The limited literature data also suggests that the addition of BoNTs to the culture of cancer cell lines reduces cell growth, and mitotic activity, and promotes their apoptosis. BoNTs have several advantages that can be emphasized: BoNTs act on both perfusion and oxygenation; moreover, BoNTs are considered to be safe and free of systemic side effects upon administration. Recently, advances in molecular biology techniques have allowed a wide variety of novel BoNT constructs with alternative functions. These constructs could be assessed as potential new classes of anti-cancer drugs. This creates new potential perspectives in the wider use of non-toxic modified BoNT constructs in cancer therapy. In the light of the mentioned premises and existing literature reports, the aim of this review is to summarize current data and reports considering BoNT use in cancer therapy. KEY POINTS : •Botulinum toxin (BoNTs) may be useful in cancer treatment. •Botulinum toxin can serve as an analgesic after cancer radiotherapy. •Botulinum toxin has the ability to inhibit tumor growth and promote apoptosis of neoplastic cells.

A Family Outbreak of Type E Botulism Caused by Contaminated Vacuum-Packed Ambient-Stored Chili Chicken Feet in Zhangjiakou, China.

The epidemiological investigation and laboratory-based confirmation were performed on samples from a family botulism outbreak in Zhangjiakou, Hebei province, China. Forty-four samples, including 14 samples (leftover food, and swabs taken of both food packaging bags and dishes, and serum and vomitus of the victims) related to outbreak and 30 causative food products after outbreak, were collected and analyzed. Isolation, bacterial identification, toxin detection, and whole-genome sequencing of Clostridium spp. cultured from the latter samples and animal assays were performed. Mice injected with the cultures of the leftover chili chicken feet, together with the inner layer of its packaging bag, the plate for serving it, and supernatant of two patients' serum that demonstrated the typical signs of botulism. The polyvalent anti-botulinum neurotoxin (BoNT) and the monovalent anti-BoNT/E exhibited protective effects when administered to mice. Three Clostridium botulinum cultures were obtained and verified to be positive for BoNT/E. The whole genome analysis of the isolates revealed that the classic bont/e gene orfX cluster was found to be located on the chromosomes of all three isolates. Single nucleotide polymorphism analysis suggested that these might be from the same source. Our findings indicated that this botulism outbreak occurred following the ingestion of vacuum-packed chili chicken feet contaminated with BoNT/E produced by C. botulinum.

A Phase 3, Randomized, Multi-center Clinical Trial to Evaluate the Efficacy and Safety of Neu-BoNT/A in Treatment of Primary Axillary Hyperhidrosis.

BACKGROUND: Botulinum toxin type A is widely used to treat primary axillary hyperhidrosis and has proven to be an effective and safe approach. Onabotulinumtoxin A was approved by the FDA as a treatment for primary axillary hyperhidrosis. This study aimed to evaluate the efficacy and safety of Neu-BoNT/A in subjects diagnosed with primary axillary hyperhidrosis. METHODS: The Hyperhidrosis Disease Severity Scale, gravimetric measurement of sweat, and Global Assessment Scale were analyzed at weeks 4, 8, 12, and 16 to determine the effect of treatment. Adverse events, physical examination, and vital signs were monitored. RESULTS: Subjects treated with Neu-BoNT/A showed statistically significant improvement by all 3 methods at weeks 4, 8, 12, and 16 (P value = 0.00). There were no severe adverse events or significant changes in vital signs, physical examination, or laboratory tests. CONCLUSION: Neu-BoNT/A can be effectively and safely used for primary axillary hyperhidrosis. LEVEL OF EVIDENCE II: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The synaptic blocker botulinum toxin A decreases the density and complexity of oligodendrocyte precursor cells in the adult mouse hippocampus.

Oligodendrocyte progenitor cells (OPCs) are responsible for generating oligodendrocytes, the myelinating cells of the CNS. Life-long myelination is promoted by neuronal activity and is essential for neural network plasticity and learning. OPCs are known to contact synapses and it is proposed that neuronal synaptic activity in turn regulates their behavior. To examine this in the adult, we performed unilateral injection of the synaptic blocker botulinum neurotoxin A (BoNT/A) into the hippocampus of adult mice. We confirm BoNT/A cleaves SNAP-25 in the CA1 are of the hippocampus, which has been proven to block neurotransmission. Notably, BoNT/A significantly decreased OPC density and caused their shrinkage, as determined by immunolabeling for the OPC marker NG2. Furthermore, BoNT/A resulted in an overall decrease in the number of OPC processes, as well as a decrease in their lengths and branching frequency. These data indicate that synaptic activity is important for maintaining adult OPC numbers and cellular integrity, which is relevant to pathophysiological scenarios characterized by dysregulation of synaptic activity, such as age-related cognitive decline, Multiple Sclerosis and Alzheimer's disease.

Modification and validation of the Endopep-mass spectrometry method for botulinum neurotoxin detection in liver samples with application to samples collected during animal botulism outbreaks.

Botulinum neurotoxins (BoNTs) are the most potent toxins known and they cause the paralytic disease botulism in humans and animals. In order to diagnose botulism, active BoNT must be detected in biological material. Endopep-MS is a sensitive and selective method for serum samples, based on antibody capture, enzymatic cleavage of target peptides, and detection of cleavage products using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS). In many cases of animal botulism, serum samples are not available or they do not contain detectable amounts of BoNT and liver sampling is an alternative for postmortem examinations. However, the Endopep-MS method is impaired by the inherent protease activity of liver samples. In the presented study, the Endopep-MS method has been successfully modified and validated for analysis of cattle, horse, and avian liver samples, introducing a combination of a salt washing step and a protease inhibitor cocktail. These modifications resulted in a substantial decrease in interfering signals and increase in BoNT-specific signals. This led to a substantial improvement in sensitivity for especially BoNT-C and C/D which are among the most prominent serotypes for animal botulism. Botulism was diagnosed with the new method in liver samples from dead cattle and birds from outbreaks in Sweden. Graphical Abstract.

The Structure and Classification of Botulinum Toxins.

Botulinum neurotoxins (BoNTs) are a family of bacterial protein toxins produced by various Clostridium species. They are traditionally classified into seven major serotypes (BoNT/A-G). Recent progress in sequencing microbial genomes has led to an ever-growing number of subtypes, chimeric toxins, BoNT-like toxins, and remotely related BoNT homologs, constituting an expanding BoNT superfamily. Recent structural studies of BoNTs, BoNT progenitor toxin complexes, tetanus neurotoxin (TeNT), toxin-receptor complexes, and toxin-substrate complexes have provided mechanistic understandings of toxin functions and the molecular basis for their variations. The growing BoNT superfamily of toxins present a natural repertoire that can be explored to develop novel therapeutic toxins, and the structural understanding of their variations provides a knowledge basis for engineering toxins to improve therapeutic efficacy and expand their clinical applications.

Botulinum toxin treatment for difficult-to-treat finger pressure ulcers caused by severe hand flexion: case report.

We report the successful treatment of two cases of difficult-to-treat pressure ulcers with botulinum toxin type A (BoNT-A). A 71-year-old male patient with Parkinson's disease presented with severe hand grip deformities of the fingers and a pressure ulcer (PU) on the right hand. He received 240U of BoNT-A into the upper limb muscles, which improved finger mobility during passive extension and resulted in resolution of the palm PU. No recurrence was noted. A 69-year-old female patient with Lewy body dementia presented with a PU on the palm side of the middle finger apex of the right hand, with exposure of the phalanx bone and dark red oedematous granulation of the tip of the finger. Severe muscle tone was noted. She received 240U of BoNT-A injected into the muscles of the upper extremities. This resulted in the disappearance of the contracture between the middle finger cusp and palm, and prompt healing of the PU. A protective finger orthosis was also used to improve hand finger grip and prevent further PUs. Although BoNT-A injection resulted in only slight improvement in the range of motion, it produced relief of pressure with consequent healing of the PU. Injection of BoNT-A into the affected muscles of the patients in this case report was effective in reducing flexor muscle tone, relief of pressure on the palm skin and healing of hand PUs.