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1.
Toxins (Basel) ; 14(4)2022 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-35448855

RESUMO

The motor behaviour of patients with Upper Motor Neuron Syndrome (UMNS) is characterised by spasticity. The first-line treatment for this clinical condition is Botulinum neurotoxin A (BoNTA), but the number and key locations of muscles which need to be treated is not much discussed in the literature. Cross-sectional analysis of outpatient cohort with UMNS spasticity, who were potential candidates for BoNTA treatment, was performed. Between November 2020 and November 2021, all consecutive adult patients eligible for BoNTA treatment were enrolled. The inclusion criteria encompass UMNS spasticity (onset being ≥6 months), with disabling muscles hypertonia. Patients underwent a clinical evaluation, a comprehensive assessment with the Modified Ashworth Scale, with the Modified Rankin Scale, and a patients' perception-centred questionnaire. In total, 68 participants were enrolled in the study, among them 40 (58.8%) were male; mean age 57.9 ± 15.1. In women, BoNTA was more frequently required for adductor group muscles, independently from potential confounders (OR = 7.03, 95%CI: 1.90-25.97). According to the pattern of disability, patients with hemiparesis more frequently need to be treated in the upper limb, whereas the diplegia/double-hemiparesis group needed to be treated more frequently at the adductor and crux muscles compared to their counterparts. UMNS spasticity in women could require more attention to be paid to the treatment of adductor muscle spasticity, potentially because the dysfunction of those muscles could influence sphincteric management, required for perineal hygiene and/or sexual life.


Assuntos
Toxinas Botulínicas Tipo A , Fármacos Neuromusculares , Acidente Vascular Cerebral , Adulto , Idoso , Toxinas Botulínicas Tipo A/toxicidade , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neurônios Motores , Espasticidade Muscular/tratamento farmacológico , Espasticidade Muscular/etiologia , Fármacos Neuromusculares/uso terapêutico , Fármacos Neuromusculares/toxicidade , Paresia/induzido quimicamente , Acidente Vascular Cerebral/complicações , Síndrome , Resultado do Tratamento , Extremidade Superior
2.
J Neuroimmunol ; 361: 577726, 2021 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-34628135

RESUMO

We describe a case of a 28-year-old man who developed a cervical myelitis while exposed to ixekizumab (IL-17 inhibitor) for psoriatic arthritis. Spinal MRI showed a T2 hyperintense lesion at the C4-C5 level while brain MRI was unspecific. Oligoclonal bands were absent and extensive screening for autoimmunity was negative. Rechallenge with ixekizumab was positive corroborating a relation between drug exposure and the neurological event. To the best of our knowledge, this is the first case of CNS inflammatory adverse event associated with ixekizumab. We also provide a review of case reports of demyelinating disorders associated with the use of biologic drugs for the treatment of psoriasis and psoriatic arthritis.


Assuntos
Anticorpos Monoclonais Humanizados/efeitos adversos , Fatores Imunológicos/efeitos adversos , Mielite/induzido quimicamente , Adolescente , Corticosteroides/uso terapêutico , Adulto , Anticorpos Monoclonais Humanizados/uso terapêutico , Antirreumáticos/efeitos adversos , Artrite Psoriásica/tratamento farmacológico , Mapeamento Encefálico , Substituição de Medicamentos , Feminino , Humanos , Hipestesia/induzido quimicamente , Fatores Imunológicos/uso terapêutico , Interleucina-17/antagonistas & inibidores , Perna (Membro)/inervação , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Mielite/diagnóstico por imagem , Mielite/tratamento farmacológico , Paresia/induzido quimicamente , Medula Espinal/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Adulto Jovem
3.
Reg Anesth Pain Med ; 45(12): 979-984, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33004656

RESUMO

BACKGROUND: There is no consensus regarding what volume of local anesthetic should be used to achieve successful supraclavicular block while minimizing hemidiaphragmatic paresis (HDP). This study investigated the dose-response relationship between local anesthetic volume and HDP after ultrasound-guided supraclavicular brachial plexus block. METHODS: A dose escalation design was used to define the dose response curve for local anesthetic volume and incidence of HDP in subjects undergoing upper extremity surgery with supraclavicular block as the primary anesthetic. Dosing levels of 5, 10, 15, 20, 25, 30, 35 and 40 mL of local anesthetic were administered in cohorts of three subjects per dose. Diaphragm function was assessed with M-mode ultrasound before and after block. Secondary objectives included assessment of negative inspiratory force (NIF), oxygen saturation, subjective dyspnea and extent of sensory and motor blockade. RESULTS: Twenty-one subjects completed the study. HDP was present at all doses, with an incidence of 33% at 5 mL to 100% at 30-35 mL. There was a significant decrease in NIF (7.5 cmH2O, IQR (22,0); p=0.01) and oxygen saturation on room air (1%, IQR (2,0); p=0.01) 30 min postblock in subjects experiencing HDP but not in those without HDP. There was no increase in dyspnea in subjects with or without HDP. No subject required respiratory intervention. Motor and sensory block improved with increasing dose, and subjects with HDP exhibited denser blocks than those without (p<0.01). CONCLUSIONS: There is no clinically relevant volume of local anesthetic at which HDP can be avoided when performing a supraclavicular block. In our subject population free of respiratory disease, HDP was well tolerated. TRIAL REGISTRATION NUMBER: NCT03138577.


Assuntos
Bloqueio do Plexo Braquial , Anestésicos Locais/efeitos adversos , Bloqueio do Plexo Braquial/efeitos adversos , Humanos , Paresia/induzido quimicamente , Paresia/diagnóstico , Ultrassonografia , Ultrassonografia de Intervenção
4.
BMJ Case Rep ; 13(5)2020 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-32430349

RESUMO

Children with Down syndrome have a higher risk of stroke. Similarly, intravenous immunoglobulin (IV Ig) is also known to cause a stroke. We reported a 3-year-old boy with Down syndrome who presented with severe pneumonia and received IV Ig. He developed right hemiparesis 60 hours after the infusion. Blood investigations, echocardiography and carotid Doppler did not suggest vasculitis, thrombophilia or extracranial dissection. Brain computerised tomography (CT) showed acute left frontal and parietal infarcts. Initial magnetic resonance angiography (MRA) of cerebral vessels showed short segment attenuations of both proximal middle cerebral arteries and reduction in the calibre of bilateral supraclinoid internal carotid arteries. The boy was treated with enoxaparin and aspirin. He only had partial recovery of the hemiparesis on follow-up. A repeat MRA 13 months later showed parenchymal collateral vessels suggestive of moyamoya disease. We recommend imaging the cerebral vessels in children with a high risk of moyamoya before giving IV Ig.


Assuntos
Imunoglobulinas Intravenosas/efeitos adversos , Doença de Moyamoya/diagnóstico por imagem , Paresia/induzido quimicamente , Acidente Vascular Cerebral/induzido quimicamente , Pré-Escolar , Síndrome de Down/complicações , Fibrinolíticos/uso terapêutico , Seguimentos , Humanos , Angiografia por Ressonância Magnética , Masculino , Doença de Moyamoya/tratamento farmacológico , Paresia/tratamento farmacológico , Acidente Vascular Cerebral/tratamento farmacológico , Resultado do Tratamento
5.
Toxins (Basel) ; 12(3)2020 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-32245200

RESUMO

We report the discovery and functional characterization of αM-Conotoxin MIIIJ, a peptide from the venom of the fish-hunting cone snail Conus magus. Injections of αM-MIIIJ induced paralysis in goldfish (Carassius auratus) but not mice. Intracellular recording from skeletal muscles of fish (C. auratus) and frog (Xenopus laevis) revealed that αM-MIIIJ inhibited postsynaptic nicotinic acetylcholine receptors (nAChRs) with an IC50 of ~0.1 µM. With comparable potency, αM-MIIIJ reversibly blocked ACh-gated currents (IACh) of voltage-clamped X. laevis oocytes exogenously expressing nAChRs cloned from zebrafish (Danio rerio) muscle. αM-MIIIJ also protected against slowly-reversible block of IACh by α-bungarotoxin (α-BgTX, a snake neurotoxin) and α-conotoxin EI (α-EI, from Conus ermineus another fish hunter) that competitively block nAChRs at the ACh binding site. Furthermore, assessment by fluorescence microscopy showed that αM-MIIIJ inhibited the binding of fluorescently-tagged α-BgTX at neuromuscular junctions of X. laevis,C. auratus, and D. rerio. (Note, we observed that αM-MIIIJ can block adult mouse and human muscle nAChRs exogenously expressed in X. laevis oocytes, but with IC50s ~100-times higher than those of zebrafish nAChRs.) Taken together, these results indicate that αM-MIIIJ inhibits muscle nAChRs and furthermore apparently does so by interfering with the binding of ACh to its receptor. Comparative alignments with homologous sequences identified in other fish hunters revealed that αM-MIIIJ defines a new class of muscle nAChR inhibitors from cone snails.


Assuntos
Conotoxinas/farmacologia , Músculo Esquelético/efeitos dos fármacos , Junção Neuromuscular/efeitos dos fármacos , Antagonistas Nicotínicos/farmacologia , Receptores Nicotínicos/metabolismo , Potenciais de Ação/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Conotoxinas/química , Relação Dose-Resposta a Droga , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Carpa Dourada , Camundongos , Músculo Esquelético/metabolismo , Junção Neuromuscular/metabolismo , Antagonistas Nicotínicos/química , Paresia/induzido quimicamente , Comportamento Predatório/efeitos dos fármacos , Ligação Proteica , Alinhamento de Sequência , Especificidade da Espécie , Xenopus laevis
6.
J Med Case Rep ; 13(1): 390, 2019 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-31875786

RESUMO

BACKGROUND: Idarucizumab is a specific antidote for the anticoagulant dabigatran. Although its efficacy has been recently reported, the drug is still in postmarketing surveillance and requires case data in different emergency settings. A newer intravenous thrombolytic therapy with recombinant tissue plasminogen activator has been proposed after injection of idarucizumab in patients receiving dabigatran; however, the safety and efficacy of this therapy are equivocal because of the limited number of reported cases. We describe a case of a patient with acute lacunar stroke causing dysarthria and hemiparesis successfully treated with intravenous thrombolytic therapy with recombinant tissue plasminogen activator after reversal of dabigatran with idarucizumab. CASE PRESENTATION: A 67-year-old Asian woman was transferred to our emergency center 200 minutes after sudden onset of dysarthria and right-sided hemiparesis. She had been taking dabigatran for prevention of stroke recurrence caused by atrial fibrillation. Diffusion-weighted magnetic resonance imaging revealed a new lacunar infarction near old putamen infarctions. We treated her with intravenous thrombolytic therapy with recombinant tissue plasminogen activator after administering idarucizumab. The time to recombinant tissue plasminogen activator administration was 5 minutes from idarucizumab injection and 269 minutes from symptom onset. The patient's activated partial thromboplastin times were 68.0 and 43.2 seconds before and after the therapy, respectively. The patient's neurological symptoms improved significantly after the treatment, and she experienced no adverse events. CONCLUSIONS: Intravenous thrombolytic therapy with recombinant tissue plasminogen activator after reversal of dabigatran with idarucizumab may be safe and feasible in patients with acute ischemic stroke with lacunar infarct. Furthermore, intravenous thrombolytic therapy with recombinant tissue plasminogen activator could be used in patients in emergency settings until just before the end of the recommended time limit within which it needs to be administered because of the immediate effect of idarucizumab.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Dabigatrana/efeitos adversos , Disartria/induzido quimicamente , Paresia/induzido quimicamente , Acidente Vascular Cerebral/tratamento farmacológico , Ativador de Plasminogênio Tecidual/uso terapêutico , Idoso , Dabigatrana/uso terapêutico , Feminino , Humanos , Acidente Vascular Cerebral/prevenção & controle , Resultado do Tratamento
9.
Am J Case Rep ; 20: 1002-1005, 2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31295228

RESUMO

BACKGROUND Intraventricular administration of methotrexate (MTX) using an Ommaya reservoir is a useful therapeutic maneuver for malignant CNS involvement in patients with hematological malignancies. MTX-induced subacute neurotoxicity is a rare complication that typically progresses with involvement of the basal ganglia. Local toxicity due to misplaced catheters has been described, although the impact of normally positioned catheters on toxicity is not clear. CASE REPORT We report the case of a 21-year-old man diagnosed with stage IV diffuse large B-cell lymphoma who experienced a central nervous system relapse. While receiving intraventricular MTX using an Ommaya reservoir and systemic MTX, he experienced sudden left-side hemiparesis. All diagnostic tests were negative except for altered MRI findings with FLAIR hyperintensity in the basal ganglia and restricted diffusion in the same location that followed the track of the Ommaya catheter. The syndrome resolved after administration of high-dose steroids, and the patient received subsequent MTX courses without recurrence. CONCLUSIONS MTX-induced neurotoxicity is a rare adverse event related to systemic and intrathecal administration of the drug. Many cases of Ommaya-related CNS symptoms have been described, although most were related to misplaced or malfunctioning catheters. Here we present a case of subacute MTX toxicity affecting the area around a correctly positioned catheter, suggesting that the catheter track could be more susceptible to MTX-induced toxicity.


Assuntos
Antimetabólitos Antineoplásicos/toxicidade , Cateteres de Demora , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Metotrexato/toxicidade , Síndromes Neurotóxicas/etiologia , Paresia/induzido quimicamente , Diagnóstico Diferencial , Humanos , Masculino , Adulto Jovem
10.
BMJ Case Rep ; 11(1)2018 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-30567254

RESUMO

The consumption of daily nutritional supplements has risen dramatically all over the world. Many people believe that dietary supplements, if not useful, are at least safe to fulfil small dietary gaps. Many nutritional supplements have not been approved by Federal Drug Administration due to their unregulated active ingredients, but they are available as over the counter. One of the active ingredients, exogenous triiodothyronine (T3), has been reported in dietary supplements. We present a case of sudden onset of tetraparesis. Laboratory workup showed hypokalaemia, low thyroid-stimulating hormone and thyroxine (T4) but normal T3 and thyroglobulin levels. The radioiodine uptake scan also showed reduced uptake. After aggressive serum potassium correction and stopping supplements, his condition got improved. So the suspicion of exogenous T3-induced thyrotoxic periodic paralysis was confirmed.


Assuntos
Suplementos Nutricionais/efeitos adversos , Paresia/induzido quimicamente , Tri-Iodotironina/efeitos adversos , Adulto , Humanos , Hipopotassemia/sangue , Hipopotassemia/induzido quimicamente , Masculino , Paresia/sangue , Tireotropina/sangue , Tiroxina/sangue
11.
J Stroke Cerebrovasc Dis ; 27(11): e233-e235, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30049517

RESUMO

We report a 35-year-old woman who suddenly developed left hemiparesis and dysarthria at 13days after treatment with intrathecal and intravenous methotrexate for intravascular large B cell lymphoma with possible central nervous system infiltration. Seven hours after onset, she developed further right hemiparesis and aphasia. However, the majority of neurologic symptoms disappeared spontaneously and completely by 34hours. We also recorded the dynamic progression and regression of abnormal signals in the bilateral corona radiata on diffusion-weighted imaging, in parallel with neurologic symptoms. The rapid reversal of MR abnormalities and neurologic symptoms allowed us to diagnose methotrexate encephalopathy, and exclude intravascular large B cell lymphoma recurrence and regular brain infarction. The case provides new data on the dynamic changes of abnormal signals on magnetic resonance imaging in methotrexate encephalopathy over a short recovery time.


Assuntos
Antimetabólitos Antineoplásicos/efeitos adversos , Isquemia Encefálica/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Encefalite/induzido quimicamente , Encefalite/diagnóstico por imagem , Linfoma de Células B/tratamento farmacológico , Metotrexato/efeitos adversos , Acidente Vascular Cerebral/diagnóstico por imagem , Adulto , Diagnóstico Diferencial , Disartria/induzido quimicamente , Diagnóstico Precoce , Feminino , Humanos , Linfoma de Células B/patologia , Paresia/induzido quimicamente , Valor Preditivo dos Testes
14.
Pediatr Emerg Care ; 34(3): e47-e50, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27668914

RESUMO

Emergency departments (EDs) are alert to the possibility of stroke and the need for early interventions to improve long-term clinical outcomes. However, new-onset hemiparesis in pediatric patients with leukemia may be due to a number of different etiologies, including most common side effects from chemotherapeutic agents. We present a case of a 15-year-old boy with pre-B acute lymphoblastic leukemia on chemotherapy, having recently received a high-dose methotrexate infusion in addition to intrathecal methotrexate therapy, who presented to our ED with acute right-sided hemiparesis. He was initially suspected as having a possible ischemic stroke. Magnetic resonance imaging (diffusion-weighted and fluid-attenuated inversion recovery sequence) demonstrated focal areas of diffusion restriction, an early sign of delayed-onset methotrexate neurotoxicity. Our patient received appropriate supportive care and leucovorin rescue with gradual clinical recovery, after a prolonged hospitalization and acute care rehabilitation over the course of several months. Our case illustrates the need for ED providers to consider methotrexate neurotoxicity in pediatric oncology patients presenting with acute neurologic changes.


Assuntos
Antimetabólitos Antineoplásicos/efeitos adversos , Metotrexato/efeitos adversos , Síndromes Neurotóxicas/diagnóstico , Paresia/induzido quimicamente , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Adolescente , Antídotos/uso terapêutico , Antimetabólitos Antineoplásicos/administração & dosagem , Encéfalo/patologia , Imagem de Difusão por Ressonância Magnética , Humanos , Leucovorina/uso terapêutico , Masculino , Síndromes Neurotóxicas/etiologia , Paresia/terapia
15.
Intern Med ; 57(4): 591-594, 2018 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-29225249

RESUMO

A 63-year-old man developed vomiting, paraparesis, dysuria, bulbar palsy, and orthostatic hypotension over a period of 5 months. Neuroradiological examinations showed a swollen lower brainstem with a dural arteriovenous fistula at the craniocervical junction (DAVF-CCJ). A steroid was administered intravenously in the hospital to relieve brainstem edema. A few hours later, however, the patient developed acute tetraparesis with respiratory failure. Recently, there have been several reports describing the acute worsening of paraparesis in patients with a spinal dural arteriovenous fistula after steroid treatment. In addition to these reports, the present case suggests the risk of administering steroids to patients with DAVF-CCJ, especially those with brainstem dysfunction.


Assuntos
Anti-Inflamatórios/efeitos adversos , Betametasona/efeitos adversos , Edema Encefálico/tratamento farmacológico , Malformações Vasculares do Sistema Nervoso Central/complicações , Paresia/induzido quimicamente , Insuficiência Respiratória/induzido quimicamente , Doença Aguda , Anti-Inflamatórios/uso terapêutico , Betametasona/uso terapêutico , Edema Encefálico/etiologia , Malformações Vasculares do Sistema Nervoso Central/diagnóstico , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Paresia/diagnóstico , Insuficiência Respiratória/diagnóstico
16.
Neth J Med ; 75(7): 304-306, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28956785

RESUMO

We present a case of non-immune haemolytic anaemia with leukopenia and acute severe neurological impairments, as a result of severe vitamin B12 deficiency due to recreational use of nitrous oxide.


Assuntos
Anemia Hemolítica/induzido quimicamente , Leucopenia/induzido quimicamente , Óxido Nitroso/toxicidade , Paresia/induzido quimicamente , Transtornos Relacionados ao Uso de Substâncias/complicações , Deficiência de Vitamina B 12/induzido quimicamente , Feminino , Humanos , Adulto Jovem
18.
BMJ Case Rep ; 20172017 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-28630245

RESUMO

Testicular tumours are the most common tumours in young men. Germ cell tumours (GCTs) account for 95% of all testicular cancers, and the non-seminomatous type (NSGCT) accounts for 50% of all GCTs. Cisplatin-based chemotherapy is curative in up to 90% of patients, but it is not without its inherent risks. Ischaemic stroke is a very uncommon, but severe complication of cisplatin-based chemotherapy. Strokes in young patients cause a disproportionately large economic impact by leaving victims disabled during their most productive years and strains the healthcare system with expensive hospital stays. We present a case of a young male patient with past medical history of metastatic NSGCT with the sudden onset of dysarthria, left hemiplegia and ipsilateral hemisensory loss 3 days after receiving cisplatin-based chemotherapy. Subsequent studies revealed a stroke involving the right middle cerebral artery territory secondary to an acute right internal carotid occlusion.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Aspirina/uso terapêutico , Doenças das Artérias Carótidas/induzido quimicamente , Cisplatino/efeitos adversos , Neoplasias Embrionárias de Células Germinativas/tratamento farmacológico , Acidente Vascular Cerebral/induzido quimicamente , Neoplasias Testiculares/tratamento farmacológico , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Doenças das Artérias Carótidas/tratamento farmacológico , Cisplatino/administração & dosagem , Humanos , Masculino , Neoplasias Embrionárias de Células Germinativas/secundário , Paresia/induzido quimicamente , Acidente Vascular Cerebral/tratamento farmacológico , Neoplasias Testiculares/secundário , Resultado do Tratamento
19.
Ann Dermatol Venereol ; 144(6-7): 426-429, 2017.
Artigo em Francês | MEDLINE | ID: mdl-28412011

RESUMO

BACKGROUND: Nicolau syndrome is a rare condition consisting in tissue ischemia and necrosis following intramuscular, intra-articular or subcutaneous injection. PATIENTS AND METHODS: Immediately after gluteal intramuscular injection of benzathine-penicillin, a 10-year-old male child presented an extensive painful violaceous lesion on the left buttock associated with urinary incontinence and left lower-limb paresis. Additional underlying muscular damage was supported by high serum levels of creatine kinase and lactate dehydrogenase. Treatment was based on fluid expansion, intravenous steroids and anticoagulants, resulting in improvement of cutaneous and muscular lesions. Improvement in terms of neurological dysfunction was obtained after regular neuromuscular rehabilitation. DISCUSSION: This case underlines the need to prevent Nicolau syndrome by means of compliance with the technical recommendations for intramuscular injections.


Assuntos
Antibacterianos/efeitos adversos , Síndrome de Nicolau/diagnóstico , Síndrome de Nicolau/etiologia , Penicilina G Benzatina/efeitos adversos , Antibacterianos/administração & dosagem , Anticoagulantes/uso terapêutico , Nádegas/patologia , Criança , Quimioterapia Combinada , Glucocorticoides/uso terapêutico , Humanos , Injeções Intramusculares/efeitos adversos , Masculino , Síndrome de Nicolau/tratamento farmacológico , Paresia/induzido quimicamente , Penicilina G Benzatina/administração & dosagem , Resultado do Tratamento , Incontinência Urinária/induzido quimicamente
20.
Neurotoxicology ; 59: 1-8, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28043867

RESUMO

The highly potent Botulinum neurotoxins (BoNT) are successful drugs to treat neuromuscular disorders. Efforts are being made to further reduce the injected BoNT dose and to lengthen the interval between treatments. Detailed knowledge of the BoNT structure-activity relationship (SAR) allows combining the best features of the different BoNT serotypes. Of all seven BoNT serotypes A-G, BoNT/A displays the highest potency despite low neuronal binding affinity, while BoNT/B exhibits much higher affinity. Recently, a new BoNT/AB hybrid (AABB) was constructed comprising the catalytic and translocation domain of BoNT/A and the 50kDa cell binding domain of BoNT/B. Here, we compared BoNT/A wild-type (AAAA) and AABB with regard to ex vivo potency and in vivo potency, efficacy and duration of action using the mouse phrenic nerve hemidiaphragm assay and the murine running wheel assay, respectively. The ex vivo potency of AABB was found to be 8.4-fold higher than that of AAAA. For the latter, two and 5 pg each of AAAA and AABB, respectively, were bilaterally injected into the calf muscles and mouse running wheel performance was automatically monitored during the following weeks to determine potency, efficacy and duration. Mice displayed a dose-dependent impairment of running performance. AABB showed potency, efficacy and duration equal to AAAA demonstrating successful exchange of the cell binding domain. AABB might combine the higher potency and longer duration of BoNT/A with the target specificity for the autonomic nervous system of BoNT/B. AABB might therefore constitute an improved treatment option for acetylcholine-mediated autonomic disorders such as hypersalivation or hyperhidrosis.


Assuntos
Toxinas Botulínicas Tipo A/farmacologia , Músculo Esquelético/efeitos dos fármacos , Neurotoxinas/farmacologia , Paresia/induzido quimicamente , Corrida/fisiologia , Análise de Variância , Animais , Diafragma/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Masculino , Camundongos , Músculo Esquelético/fisiopatologia , Paresia/fisiopatologia , Nervo Frênico/efeitos dos fármacos , Nervo Frênico/fisiologia
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