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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Efekt prolongovaného strečinku na kontrakturu spastického svalu před a po aplikaci botulotoxinu - A / The effect of prolonged stretching on spastic muscle contracture before and after Botulinum toxin A application

Miňová, Zuzana January 2021 (has links)
A large proportion of patients with central motoneuron lesions is at risk of spastic paresis and formation of contractures. One of the therapeutic techniques used in patients with spastic paresis is prolonged stretching. The theoretical part summarizes the knowledge regarding spastic paresis, its clinical evaluation, the development of contractures and therapeutic interventions, especially botulinum toxin (BTX) and stretching. The aim of this study was to compare the effectiveness of prolonged stretching on spastic muscle contracture before and after BTX application. In our retrospective comparative study there were included 30 patients divided into two groups. The first group consisted of 15 patients performing prolonged stretching of the m. rectus femoris (m. RF) for three months according to Guided Self-rehabilitation Contract of Professor J. M. Gracies. The second group (15 patients) performing the same procedure, but at the same time BTX was injected into the m. RF. We monitored the change in passive knee joint range of motion into flexion and the change in 10MWT time. Statistical evaluation showed that the difference in knee joint range of motion after three months of performing prolonged stretching was statistically insignificant (p=0.194). The difference in knee joint range of motion after...
192

Theoretical Studies of Molecular Recognition in Protein-Ligand and Protein-Protein Complexes

Yang, Hui January 2010 (has links)
No description available.
193

Efeito da toxina botulínica tipo A sobre a expressão de neuropeptídeos e o transporte mucociliar nasal em coelhos / Effect of botulinum toxin type A on nasal neuropeptides and mucociliary clearance in rabbits

Carreirão Neto, Waldir 26 August 2015 (has links)
INTRODUÇÃO: A toxina botulínica tipo A (TXB-A) tem sido testada no tratamento da rinite, principalmente nos casos de rinite idiopática. Sugere-se que um estado de hiper-reatividade do nervo trigêmeo esteja envolvido na fisiopatologia da rinite idiopática. O nervo trigêmeo possui fibras sensitivas não mielinizadas tipo C (FSNMT-C) que contém os neuropeptídeos substância P (SP) e peptídeo relacionado ao gene da calcitonina (CGRP). O óxido nítrico (NO) produzido pelas enzimas óxido nítrico sintase (NOS) também está envolvido nesse processo de neurorregulação nasal. O transporte mucociliar, mecanismo primário de defesa do sistema respiratório, é formado pelo batimento ciliar e muco nasal, e esses componentes podem ser influenciados por diferentes neuropeptídeos e neurotransmissores presentes na mucosa nasal. OBJETIVO: O objetivo deste estudo foi avaliar o efeito da TXB-A sobre a expressão da SP, CGRP e óxido nítrico sintase neural (nNOS), além de sua influência sobre o transporte mucociliar nasal em coelhos. MÉTODOS: Coelhos machos saudáveis da linhagem Nova Zelândia foram divididos em dois grupos: o grupo tratamento recebeu TXB-A (25UI) na concha nasomaxilar (CNM) do lado direito e soro fisiológico a 0,9% (SF0,9%) na CNM esquerda. O grupo controle recebeu SF0,9% na CNM direita e nenhuma intervenção na CNM esquerda. Foram investigados os efeitos da TXB-A sobre a expressão da SP, CGRP e nNOS no tecido de CNM por meio da imuno-histoquímica. Para esta análise, dividiu-se o tecido em camada externa (CE, acima da membrana basal) e camada interna (CI, abaixo da membrana basal). Avaliou-se também a presença de apoptose celular, a frequência de batimento ciliar (FBC), o perfil histoquímico do muco nasal (glicoproteínas ácidas e neutras) e a espessura do epitélio (ESP-CE). RESULTADOS: Foi observado um aumento significativo na quantidade de células apoptóticas na CNM do grupo tratamento que recebeu TXB-A em comparação aos controles (p <= 0,001). A CNM do grupo tratamento que recebeu SF0,9% exibiu um aumento na quantidade de células apoptóticas na CI ao comparar com os controles (CNM SF0,9%, p=0,035) (CNM sem intervenção, p=0,022), e também um aumento da expressão de SP na CE em comparação aos controles (CNM SF0,9%, p=0,021) (CNM sem intervenção, p=0,040). A expressão de CGRP apresentou um aumento na CNM do grupo tratamento que recebeu TXB-A em comparação à CNM sem intervenção (p=0,008). A FBC, expressão de nNOS, perfil histoquímico do muco nasal e ESP-CE não apresentaram diferenças significativas. DISCUSSÃO: O aumento da expressão de CGRP e SP pode ter sido causado por inibição de sua exocitose vesicular pela TXB-A, levando ao seu acúmulo intracelular. Não foram observadas diferenças significativas na FBC ou perfil histoquímico do muco nasal, indicando que o aumento da expressão de CGRP e SP não foi associado à inflamação. O aumento da quantidade de células apoptóticas e da expressão de SP na CNM SF0,9% do grupo tratamento pode ter sido causado por um efeito central da TXB-A. CONCLUSÃO: A administração nasal de TXB-A aumentou a expressão de CGRP e SP, possivelmente por acúmulo intracelular por causa da inibição da sua exocitose, mas sem alterar a FBC e o perfil histoquímico do muco nasal / INTRODUCTION: Botulinum toxin type A (BoNT-A) has been assessed in the treatment of rhinitis, especially in cases of idiopathic rhinitis. Trigeminal hyper-responsiveness appears to be involved in the pathological process of idiopathic rhinitis. Trigeminal nociceptive type C unmyelinated sensory fibers contain the neuropeptides calcitonin gene-related peptide (CGRP) and substance P (SP). Nitric oxide (NO) produced by the enzyme nitric oxide synthase (NOS) are also involved in this nasal neurorregulation process. The mucociliary clearance, primary defense system of the respiratory system, is composed by the ciliary beat and nasal mucus. These components can be influenced by different nasal neuropeptides and neurotransmitters. OBJECTIVE: The aim of this study was to evaluate the effect of BoNT-A on the expression of SP, CGRP and neural nitric oxide synthase (nNOS), and its influence on nasal mucociliary clearance in rabbits. METHODS: Healthy New Zealand male rabbits were divided into two groups: the treatment group was challenged with BoNT-A (25UI) in the right nasomaxillary turbinate (NMT) and saline (SF0.9%) in the left NMT. The control group received SF0.9% in the right NMT and no-intervention in the left NMT. We investigated the effects of BoNT-A on SP, CGRP and nNOS expression in the NMT tissue by immunohistochemistry. Each area of interest was subdivided into an internal layer (IL: below the basement membrane) and outer layer (OL: above the basement membrane) for analysis. It was also assessed signs of cellular apoptosis, ciliary beat frequency (CBF), mucus histochemical profile (acidic and neutral glycoproteins) and epithelial thickness (EP-TH). RESULTS: It was observed a significant increase in the amount of apoptotic cells in the BoNT-A-challanged NMT compared with controls (p <= 0.001). The NMT of treatment group which received only SF0.9% showed an increase in the amount of apoptotic cells in the IL compared with controls (NMT SF0.9%, p = 0.035) (NMT no-intervention, p = 0.022), and also an increase in the SP expression in the OL compared with controls (NMT SF0.9%, p = 0.021) (NMT no-intervention, p = 0.040). CGRP expression showed higher expression in the BoNT-A-challanged NMT compared with no-intervention NMT (p=0.008). The CBF, nNOS expression, mucus histochemical profile and EP-TH did not show significant differences. DISCUSSION: The increased CGRP and SP expression could be due to inhibition of vesicular exocytosis by BoNT-A, leading to CGRP and SP intracellular accumulation. No significant differences in CBF or mucus histochemical profile were observed, indicating that the increased CGRP and SP expression was not associated with inflammation. The increase in the amount of apoptotic cells and SP expression in the SF0.9% NMT of treatment group may be due to a central effect of BoNT-A. CONCLUSION: Nasal administration of BoNT-A increased SP and CGRP expression, possibly via inhibition of their release, but did not change the CBF or mucus profile
194

Efeito da toxina botulínica tipo A sobre a expressão de neuropeptídeos e o transporte mucociliar nasal em coelhos / Effect of botulinum toxin type A on nasal neuropeptides and mucociliary clearance in rabbits

Waldir Carreirão Neto 26 August 2015 (has links)
INTRODUÇÃO: A toxina botulínica tipo A (TXB-A) tem sido testada no tratamento da rinite, principalmente nos casos de rinite idiopática. Sugere-se que um estado de hiper-reatividade do nervo trigêmeo esteja envolvido na fisiopatologia da rinite idiopática. O nervo trigêmeo possui fibras sensitivas não mielinizadas tipo C (FSNMT-C) que contém os neuropeptídeos substância P (SP) e peptídeo relacionado ao gene da calcitonina (CGRP). O óxido nítrico (NO) produzido pelas enzimas óxido nítrico sintase (NOS) também está envolvido nesse processo de neurorregulação nasal. O transporte mucociliar, mecanismo primário de defesa do sistema respiratório, é formado pelo batimento ciliar e muco nasal, e esses componentes podem ser influenciados por diferentes neuropeptídeos e neurotransmissores presentes na mucosa nasal. OBJETIVO: O objetivo deste estudo foi avaliar o efeito da TXB-A sobre a expressão da SP, CGRP e óxido nítrico sintase neural (nNOS), além de sua influência sobre o transporte mucociliar nasal em coelhos. MÉTODOS: Coelhos machos saudáveis da linhagem Nova Zelândia foram divididos em dois grupos: o grupo tratamento recebeu TXB-A (25UI) na concha nasomaxilar (CNM) do lado direito e soro fisiológico a 0,9% (SF0,9%) na CNM esquerda. O grupo controle recebeu SF0,9% na CNM direita e nenhuma intervenção na CNM esquerda. Foram investigados os efeitos da TXB-A sobre a expressão da SP, CGRP e nNOS no tecido de CNM por meio da imuno-histoquímica. Para esta análise, dividiu-se o tecido em camada externa (CE, acima da membrana basal) e camada interna (CI, abaixo da membrana basal). Avaliou-se também a presença de apoptose celular, a frequência de batimento ciliar (FBC), o perfil histoquímico do muco nasal (glicoproteínas ácidas e neutras) e a espessura do epitélio (ESP-CE). RESULTADOS: Foi observado um aumento significativo na quantidade de células apoptóticas na CNM do grupo tratamento que recebeu TXB-A em comparação aos controles (p <= 0,001). A CNM do grupo tratamento que recebeu SF0,9% exibiu um aumento na quantidade de células apoptóticas na CI ao comparar com os controles (CNM SF0,9%, p=0,035) (CNM sem intervenção, p=0,022), e também um aumento da expressão de SP na CE em comparação aos controles (CNM SF0,9%, p=0,021) (CNM sem intervenção, p=0,040). A expressão de CGRP apresentou um aumento na CNM do grupo tratamento que recebeu TXB-A em comparação à CNM sem intervenção (p=0,008). A FBC, expressão de nNOS, perfil histoquímico do muco nasal e ESP-CE não apresentaram diferenças significativas. DISCUSSÃO: O aumento da expressão de CGRP e SP pode ter sido causado por inibição de sua exocitose vesicular pela TXB-A, levando ao seu acúmulo intracelular. Não foram observadas diferenças significativas na FBC ou perfil histoquímico do muco nasal, indicando que o aumento da expressão de CGRP e SP não foi associado à inflamação. O aumento da quantidade de células apoptóticas e da expressão de SP na CNM SF0,9% do grupo tratamento pode ter sido causado por um efeito central da TXB-A. CONCLUSÃO: A administração nasal de TXB-A aumentou a expressão de CGRP e SP, possivelmente por acúmulo intracelular por causa da inibição da sua exocitose, mas sem alterar a FBC e o perfil histoquímico do muco nasal / INTRODUCTION: Botulinum toxin type A (BoNT-A) has been assessed in the treatment of rhinitis, especially in cases of idiopathic rhinitis. Trigeminal hyper-responsiveness appears to be involved in the pathological process of idiopathic rhinitis. Trigeminal nociceptive type C unmyelinated sensory fibers contain the neuropeptides calcitonin gene-related peptide (CGRP) and substance P (SP). Nitric oxide (NO) produced by the enzyme nitric oxide synthase (NOS) are also involved in this nasal neurorregulation process. The mucociliary clearance, primary defense system of the respiratory system, is composed by the ciliary beat and nasal mucus. These components can be influenced by different nasal neuropeptides and neurotransmitters. OBJECTIVE: The aim of this study was to evaluate the effect of BoNT-A on the expression of SP, CGRP and neural nitric oxide synthase (nNOS), and its influence on nasal mucociliary clearance in rabbits. METHODS: Healthy New Zealand male rabbits were divided into two groups: the treatment group was challenged with BoNT-A (25UI) in the right nasomaxillary turbinate (NMT) and saline (SF0.9%) in the left NMT. The control group received SF0.9% in the right NMT and no-intervention in the left NMT. We investigated the effects of BoNT-A on SP, CGRP and nNOS expression in the NMT tissue by immunohistochemistry. Each area of interest was subdivided into an internal layer (IL: below the basement membrane) and outer layer (OL: above the basement membrane) for analysis. It was also assessed signs of cellular apoptosis, ciliary beat frequency (CBF), mucus histochemical profile (acidic and neutral glycoproteins) and epithelial thickness (EP-TH). RESULTS: It was observed a significant increase in the amount of apoptotic cells in the BoNT-A-challanged NMT compared with controls (p <= 0.001). The NMT of treatment group which received only SF0.9% showed an increase in the amount of apoptotic cells in the IL compared with controls (NMT SF0.9%, p = 0.035) (NMT no-intervention, p = 0.022), and also an increase in the SP expression in the OL compared with controls (NMT SF0.9%, p = 0.021) (NMT no-intervention, p = 0.040). CGRP expression showed higher expression in the BoNT-A-challanged NMT compared with no-intervention NMT (p=0.008). The CBF, nNOS expression, mucus histochemical profile and EP-TH did not show significant differences. DISCUSSION: The increased CGRP and SP expression could be due to inhibition of vesicular exocytosis by BoNT-A, leading to CGRP and SP intracellular accumulation. No significant differences in CBF or mucus histochemical profile were observed, indicating that the increased CGRP and SP expression was not associated with inflammation. The increase in the amount of apoptotic cells and SP expression in the SF0.9% NMT of treatment group may be due to a central effect of BoNT-A. CONCLUSION: Nasal administration of BoNT-A increased SP and CGRP expression, possibly via inhibition of their release, but did not change the CBF or mucus profile
195

Neurotoxins

Kostrzewa, Richard M. 01 January 2016 (has links)
The era of selective neurotoxins arose predominately in the 1960s with the discovery of the norepinephrine (NE) isomer 6-hydroxydopamine (6-OHDA), which selectively destroyed noradrenergic sympathetic nerves in rats. A series of similarly selective neurotoxins were later discovered, having high affinity for the transporter site on nerves and thus being accumulated and able to disrupt vital intraneuronal processes, to lead to cell death. The Trojan Horse botulinum neurotoxins (BoNT) and tetanus toxin bind to glycoproteins on the neuronal plasma membrane, then these stealth neurotoxins are taken inside respective cholinergic or glycinergic nerves, producing months-long functional inactivation but without overtly destroying those nerves. The mitochondrial complex I inhibitor rotenone, while lacking total specificity, still destroys dopaminergic nerves with some selectivity; and importantly, results in the neural accumulation of synuclein-to model Parkinson’s disease (PD) in animals. Other neurotoxins target specific subtypes of glutamate receptors and produce excitotoxicity in nerves with that receptor population. The dopamine D2 receptor agonist quinpirole, termed a selective neurotoxin, produces a behavioral state replicating some of the notable features of schizophrenia, but without overtly destroying nerves. These processes, mechanisms or treatment-outcomes account for the means by which neurotoxins are classified as such, and represent some of the means by which neurotoxins as a group are able to destroy or functionally inactivate nerves; or replicate an altered neurological state. Selective neurotoxins have proven to be important in gaining insight into biochemical processes and mechanisms responsible for survival or demise of a nerve. Selective neurotoxins are useful also for animal modeling of human neural disorders such as PD, Alzheimer disease, attention-deficit hyperactivity disorder (ADHD), Lesch-Nyhan disease, tardive dyskinesia, schizophrenia and others. The importance of neurotoxins in neuroscience will continue to be ever more important as even newer neurotoxins are discovered.
196

Survey of Selective Neurotoxins

Kostrzewa, Richard M. 01 January 2014 (has links)
There has been an awareness of nerve poisons from ancient times. At the dawn of the twentieth century, the actions and mechanisms of these poisons were uncovered by modern physiological and biochemical experimentation. However, the era of selective neurotoxins began with the pioneering studies of R. Levi-Montalcini through her studies of the neurotrophin "nerve growth factor" (NGF), a protein promoting growth and development of sensory and sympathetic noradrenergic nerves. An antibody to NGF, namely, anti-NGF - developed in the 1950s in a collaboration with S. Cohen - was shown to produce an "immunosympathectomy" and virtual lifelong sympathetic denervation. These Nobel Laureates thus developed and characterized the first identifiable selective neurotoxin. Other selective neurotoxins were soon discovered, and the compendium of selective neurotoxins continues to grow, so that today there are numerous selective neurotoxins, with the potential to destroy or produce dysfunction of a variety of phenotypic nerves. Selective neurotoxins are of value because of their ability to selectively destroy or disable a common group of nerves possessing (1) a particular neural transporter, (2) a unique set of enzymes or vesicular transporter, (3) a specific type of receptor or (4) membranous protein, or (5) other uniqueness. The era of selective neurotoxins has developed to such an extent that the very definition of a "selective" neurotoxin has warped. For example, (1) N-methyl-D- aspartate receptor (NMDA-R) antagonists, considered to be neuroprotectants by virtue of their prevention of excitotoxicity from glutamate receptor agonists, actually lead to the demise of populations of neurons with NMDA receptors, when administered during ontogenetic development. The mere lack of natural excitation of this nerve population, consequent to NMDA-R block, sends a message that these nerves are redundant - and an apoptotic cascade is set in motion to eliminate these nerves. (2) The rodenticide rotenone, a global cytotoxin that acts mainly to inhibit complex I in the respiratory transport chain, is now used in low dose over a period of weeks to months to produce relatively selective destruction of substantia nigra dopaminergic nerves and promote alpha-synuclein deposition in brain to thus model Parkinson's disease. Similarly, (3) glial toxins, affecting oligodendrocytes or other satellite cells, can lead to the damage or dysfunction of identifiable groups of neurons. Consequently, these toxins might also be considered as "selective neurotoxins," despite the fact that the targeted cell is nonneuronal. Likewise, (4) the dopamine D2-receptor agonist quinpirole, administered daily for a week or more, leads to development of D2-receptor supersensitivity - exaggerated responses to the D2-receptor agonist, an effect persisting lifelong. Thus, neuroprotectants can become "selective" neurotoxins; nonspecific cytotoxins can become classified as "selective" neurotoxins; and receptor agonists, under defined dosing conditions, can supersensitize and thus be classified as "selective" neurotoxins. More examples will be uncovered as the area of selective neurotoxins expands. The description and characterization of selective neurotoxins, with unmasking of their mechanisms of action, have led to a level of understanding of neuronal activity and reactivity that could not be understood by conventional physiological observations. This chapter will be useful as an introduction to the scope of the field of selective neurotoxins and provide insight for in-depth analysis in later chapters with full descriptions of selective neurotoxins.

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