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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.
61

Comparação do efeito da substância P com o do diazepam e do pentilenotetrazol no comportamento de ratos avaliados no labirinto em T

Duzzioni, Marcelo January 2005 (has links)
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas. Programa de Pós-Graduação em Farmacologia / Made available in DSpace on 2013-07-15T22:47:04Z (GMT). No. of bitstreams: 1 213767.pdf: 503822 bytes, checksum: 2a262da6b5db2cb3eedc15d7a6e29b43 (MD5) / O presente estudo teve por objetivo investigar a relação entre a substância P (SP) e o diazepam (DZP) nos comportamentos de ansiedade e memória em ratos avaliados no labirinto em T (LT). Na primeira etapa, os animais foram tratados intraperitonealmente (i.p.) com diazepam (DZP, 0,5, 1 e 2 mg/Kg; ansiolítico padrão), pentilenotetrazol (PTZ, 5, 15 e 30 mg/Kg; ansiogênico padrão), SP (5, 50 e 250 mg/Kg, droga teste) ou solução Salina (NaCl 0,9%, solução controle), antes de serem testados no LT. O procedimento experimental no teste consistiu em medir a latência para deixar o braço fechado (Linha de Base, Esquiva 1 e Esquiva 2) e aberto (Fuga 1) do aparelho; e no re-teste (72 h após) foram registrados a Esquiva 3 e a Fuga 2. Nossos resultados mostraram que a droga padrão DZP apresentou um efeito ansiolítico e/ou amnésico da memória de curta duração (STM) e a droga padrão PTZ um efeito ansiogênico e/ou facilitador na aprendizagem da esquiva inibitória. Por outro lado, a SP não apresentou per se efeito algum neste paradigma experimental. Na segunda etapa, os animais foram pré-tratados i.p. com DZP (1 mg/Kg) e tratados, pela mesma via, com Salina, SP (5 mg/Kg) ou PTZ (30 mg/Kg). Os resultados mostraram que o DZP continuou apresentando um efeito ansiolítico e/ou amnésico da STM da esquiva inibitória e que este efeito foi bloqueado e revertido tanto pelo PTZ como pela SP. Na terceira etapa, os animais foram pré-tratados i.p. com DZP (1 mg/Kg) e tratados via intracerebroventricular (i.c.v.) com SP (10 pmoL) ou PBS (controle). O DZP continuou apresentando seu(s) efeito(s) e este(s) efeito(s) sendo revertido(s) pela administração central de SP. Na quarta e última etapa, foi avaliado o envolvimento dos receptores NK1 na reversão do efeito ansiolítico e/ou amnésico produzido pelo DZP com a administração central de SP. Os animais foram pré-tratados com DZP (1 mg/Kg) i.p. e com FK 888 (100 pmoL) i.c.v. e na seqüência tratados i.c.v. com SP (10 pmoL) ou PBS. O FK 888, antagonista do receptor NK1, não interferiu per se no(s) efeito(s) do DZP, mas foi capaz de abolir a reversão do(s) efeito(s) do DZP induzido pela injeção i.c.v. de SP. A latência de fuga no teste e re-teste, bem como a memória de longa duração da esquiva inibitória não foi afetada pelos diferentes tratamentos em nenhuma das etapas experimentais avaliadas no LT. Em resumo, nossos resultados mostraram que o LT não é um modelo sensível aos efeitos tipo ansiogênico e facilitador dos processos mnemônicos da SP, além de ratificarem a interação existente entre os sistemas GABAérgico e taquicinérgico, já mostrada em outros modelos experimentais, na modulação da ansiedade e memória no LT.
62

PARTICIPAÇÃO DO SISTEMA GABAérgico NO MECANISMO DE AÇÃO ANESTÉSICA DOS ÓLEOS ESSENCIAIS DE Aloysia triphylla E Cymbopogon flexuosus EM JUNDIÁS (Rhamdia quelen) / PARTICIPATION OF THE GABAergic SYSTEM IN THE ANESTHETIC ACTION MECHANISM OF Aloysia triphylla AND Cymbopogon flexuosus ESSENTIAL OILS IN SILVER CATFISH (Rhamdia quelen)

Santos, Alessandro Casale dos 21 March 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study demonstrated the sedative and anesthetic activity of the essential oil (EO) of Cymbopogon flexuosus in the silver catfish (Rhamdia quelen). The time for induction and recovery of this EO was compared with the EO of Aloysia triphylla, due to the similarity between their major components: α-citral (geranial) and β-citral (neral). Both EOs induced anesthesia at concentrations from 150 to 300 μL L-1 and sedation at 25 μL L-1. The EO of C. flexuosus was faster in inducing the initial stages of anesthesia, but there was no significant difference to reach deep anesthesia, and there was a significantly longer recovery time. Cooperative relations and the modulation of the benzodiazepine (BDZ) site of GABAa as a mechanism of action of both EOs was verified from the addition of diazepam and flumazenil to experiments (BDZ site of GABAa agonist and antagonist, respectively). The addition of diazepam (150 μM) induced potentiation in concentrations of 25, 150 and 300 μL L-1 both EOs without significant change in anesthesia recovery time. Flumazenil (10 μM) reversed the diazepam-induced anesthesia, but not the anesthesia induced by EOs at concentrations of 150 and 300 μL L-1, thus the EO of C. flexuosus induced effective sedation and anesthesia without short-term mortality and the modulation of the BDZ site of the GABAa in the anesthetic action mechanism of both EOs in this study was not demonstrated. / Este estudo demonstrou as atividades sedativa e anestésica do óleo essencial (OE) de Cymbopogon flexuosus em jundiás (Rhamdia quelen). Os tempos de indução e recuperação relatados para esse OE foram comparados com o OE de Aloysia triphylla devido à semelhança entre os seus principais componentes: α-citral (geranial) e β-citral (neral). Ambos os OEs induziram anestesia nas concentrações de 150 a 300 μL L-1 e sedação a partir de 25 μL L-1. O OE de C. flexuosus induziu mais rapidamente fases iniciais da anestesia, mas não houve diferença significativa para alcançar o estágio de anestesia profunda, além de induzir um tempo de recuperação significativamente mais longo. As relações cooperativas e a modulação do site benzodiazepínico (BDZ) do receptor GABAa como mecanismo de ação de ambos OEs foram testados a partir da adição de diazepam e flumazenil aos experimentos (agonista e antagonista do site BDZ do GABAa, respectivamente). A adição de diazepam (150 μM) potencializou o efeito de ambos os OEs nas concentrações de 25, 150 e 300 μL L-1, sem induzir alteração significativa nos tempos de recuperação anestésica. O flumazenil (10 μM) reverteu a anestesia induzida pelo diazepam, mas não a anestesia induzida pelos OEs nas concentrações de 150 e 300 μL L-1, portanto o OE de C. flexuosus induziu sedação e anestesia efetivas sem mortalidade a curto prazo e a modulação do site BDZ do GABAa como mecanismo de ação anestésica de ambos OEs não ficou demonstrada neste estudo.
63

Determinação de pureza de fármacos por meio de métodos diretos e indiretos : vantagens e desvantagens / Quantification of drugs by means of direct and indirect methods: advantages and disadvantages

Junqueira, César Alexandre January 2012 (has links)
Pureza é um dos principais atributos de qualidade de matérias-primas farmacêuticas, já que a identificação e determinação quantitativa de impurezas podem ajudar a controlar/minimizar o risco de efeitos adversos de medicamentos. O papel dos métodos de doseamento, tanto específicos como não específicos, em caracterizar a qualidade de matérias-primas farmacêuticas, tem sido questionado. Por outro lado, a abordagem do balanço de massas, que quantifica cada impureza orgânica bem como substâncias voláteis e cinzas, e então subtrai a soma destas impurezas de 100%, pode oferecer uma melhor maneira de determinar com exatidão se o fármaco atende aos critérios regulatórios de aceitação e de detectar com confiança mudanças não esperadas na qualidade do fármaco. O objetivo do estudo foi comparar métodos de doseamento compendiais com essa abordagem de balanço de massas na determinação do conteúdo de substância ativa e caracterização da qualidade de matérias-primas farmacêuticas. Os fármacos empregados neste estudo foram o nifedipino, o diazepam, a glibenclamida e a estavudina. A identificação e caracterização dos fármacos foram realizadas por meio de determinação do ponto de fusão e espectroscopia no infravermelho. Para a determinação quantitativa foram empregados os métodos presentes na Farmacopéia Brasileira, United States Pharmacopeia e British Pharmacopeia. O detector de aerossol carregado (CAD) foi acoplado ao sistema de cromatografia à líquido de alta eficiência para comparação das respostas com o detector ultravioleta. Os resultados demonstraram a viabilidade do método indireto, que oferece dados mais precisos que os do método direto, além de favorecer um controle de qualidade mais focado no perfil de impurezas. / Purity is one of the main attributes of quality of bulk drug materials, since the identification and quantitative determination of impurities can help to avoid or at least control/minimize the risk of their contribution to the side effects profile of drug materials. The role of assay methods, either specific or non-specific, in characterizing the quality of bulk drug materials, has been questioned. On the other hand, the mass balance approach, which quantifies every organic impurity as well as volatile substances and ashes, and then subtracts the sum of these impurities from 100%, can provide a better way to accurately determine if the drug substance meets the regulatory acceptance criteria and to reliably detect unexpected changes in the quality of the drug substance. The objective of this study was to compare compendial assay methods with a mass balance approach in the determination of the active ingredient content and characterization of the quality of bulk drug materials. The identification and characterization of the drugs were accomplished through determination of melting point and infrared spectroscopy. The methods from the Farmacopeia Brasileira, United States Pharmacopeia and British Pharmacopoeia were used for the quantitative determination of the drugs. The drug related impurities were determined by high performance liquid chromatography (HPLC) equipped with an ultraviolet (UV) detector and charged aerossol detector (CAD) in tandem. The results demonstrated the feasibility of the indirect method, which offers more precise data than those from the direct method, besides it enables the quality control to be focused on the impurity profile.
64

Pathogenesis, prevention of recurrences and outcome of febrile seizures

Tarkka, R. (Rita) 05 September 2003 (has links)
Abstract Febrile seizures (FS) occur in 2-5% of children. Their pathogenesis is unknown. Elevated levels of prostaglandins (PG) have been found in cerebrospinal fluid after such seizures, and a third of all patients have recurrences. No safe ways of reducing the risk of recurrences have been found. The outcome has been shown in prospective studies to be good, by they have been linked to mesial temporal sclerosis (MTS) in patients with severe temporal lobe epilepsy (TLE). The aim was to analyze the records on the role of PGs in the pathogenesis of FS, to find risk factors for recurrences that are amenable to intervention and to evaluate the prevention of recurrences and the connection of FSs with MTS. We performed a systematic review of the effect of PGs and their synthetase inhibitors on seizures and a meta-analysis of the prevention of recurrences. The prophylactic effect of diazepam and acetaminophen on recurrences was evaluated in a placebo-controlled trial with 180 FS patients, and risk factors for recurrences were analysed from these data. To find MTS, MRI volumetry was performed after 12 years of follow-up on 64 cases chosen out of 329 unselected FS patients: twenty-four with a prolonged initial seizure, eight with a later unprovoked seizure and 32 age, sex and handedness-matched controls. PGD2, PGE1 and PGE2 had mainly anticonvulsive effects and PGF2alfa proconvulsive ones. NSAIDs had seizure-modulating effects in adult animals ranging from attenuation to provocation. Each degree of increase in fever doubled the recurrence risk, and each febrile episode increased it by 18%. The meta-analysis showed phenobarbital and valproate to prevent recurrences, but they cannot be recommended for FS as they have severe side-effects. The meta-analysis nullified the alleged effect of diazepam, and neither this nor acetaminophen prevented recurrences in a clinical trial. No MTS was found in any patient group. PGs may be involved in the pathogenesis of FS. No safe prophylaxis for recurrences is available, although the effect of antipyretics needs further evaluation. Measures to reduce feverish infections in order to prevent FS recurrences seem logical. MTS is uncommon even after prolonged FS.
65

Síntese, caracterização e avaliação das propriedades antiepilépticas de Complexos de Paládio (II) derivados do Diazepam / Synthesis, characterization and evaluation of the antiepileptic properties of diazepam-palladium (II) complexes

Correia, Walleska Bismaida Zacarias Galvão Barros 15 August 2017 (has links)
Epilepsy is a neurological disease that affects approximately 50 million people worldwide and is related to oxidative stress, which plays an important role in the neuronal damage induced by seizures. The current drugs used in the treatment of this disease have their use often limited due to their adverse effects; moreover, approximately 30% of epileptic patients who are receiving drug treatment are not totally free of seizures. These facts motivated the development of this work that aims to synthesize, characterize and evaluate palladium(II) complexes derived from diazepam in order to obtain complexes that can be used to treat epilepsy. In this work were synthesized five complexes of diazepam-palladium(II): two in dimeric form (DIAZPdOAcD and DIAZPdClD) and three in monomeric form (DIAZPdOAcPPh3, DIAZPdClPPh3 and DIAZPdClPy). All these complexes were characterized by spectrometric techniques and elemental analysis; the monomer DIAZPdOAcD had your chemical structure elucidated by X-ray diffraction. In addition, all complexes were evaluated for anticonvulsant and antioxidante activities and for citotoxicity. Through the characterization techniques used in this work it was possible to confirm the formation of all the complexes; it is important to noted that the X-ray diffraction study of DIAZPdOAcD showed the distorted square-planar geometry of palladium(II), the occurrence of cyclopalladation and the open-book shape of this dimer. Regarding the anticonvulsant and antioxidante activities, it was observed that only the DIAZPdOAcD dimer presented significant results. With respect to cytotoxicity, all complexes showed more pronounced toxicity when compared to diazepam. However, the anticonvulsive effect and the potential neuroprotective effect performed by DIAZPdOAcD should be emphasized, since they are important characteristics of new drugs for the treatment of epilepsy. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A epilepsia é uma doença neurológica que afeta aproximadamente 50 milhões de pessoas em todo o mundo e está relacionada ao estresse oxidativo, que desempenha um importante papel no dano neuronal induzido por convulsões. Os fármacos atuais utilizados no tratamento desta doença apresentam seu uso frequentemente limitado devido aos seus efeitos adversos; além disso, aproximadamente 30% dos pacientes epiléticos que estão recebendo tratamento medicamentoso não ficam totalmente livres de convulsões. Tais fatos motivaram o desenvolvimento deste trabalho que apresenta como objetivo sintetizar, caracterizar e avaliar complexos de paládio(II) derivados do diazepam com a finalidade de obter complexos que possam ser utilizados para o tratamento da epilepsia. Neste trabalho foram sintetizados cinco complexos de paládio(II) derivados do diazepam: dois na forma dimérica (DIAZPdOAcD e DIAZPdClD) e três na forma monomérica (DIAZPdOAcPPh3, DIAZPdClPPh3, e DIAZPdClPy). Todos esses complexos foram caracterizados por técnicas espectrométricas e análise elementar; e o dímero DIAZPdOAcD teve sua estrutura química elucidada através de difração de raios X. Além disso, todos os complexos foram avaliados quanto às atividades anticonvulsivante e antioxidante e à citotoxicidade. Através das técnicas de caracterização utilizadas neste trabalho foi possível confirmar a formação de todos os complexos; cabe destacar que por meio do estudo de difração de raios X do DIAZPdOAcD observou-se a geometria quadrada plana distorcida do paládio(II), a ocorrência da ciclopaladação e a forma de livro aberto deste dímero. Com relação às atividades anticonvulsivante e antioxidante, observou-se que somente o dímero DIAZPdOAcD apresentou resultados significativos. No que se refere à citotoxicidade, todos os complexos apresentaram uma maior toxicidade quando comparados ao diazepam. No entanto, cabe salientar o efeito anticonvulsivante e o potencial efeito neuroprotetor desempenhados pelo DIAZPdOAcD, pois são características importantes de novos fármacos para o tratamento da epilepsia.
66

PROCESS DEVELOPMENT FOR THE SYNTHESES OF ESSENTIAL MEDICINES IN CONTINUOUS FLOW

Robert John Nicholas (12456744) 25 April 2022 (has links)
<p>A significant number of resources are allocated to maintaining the resiliency of pharmaceutical supply chain as failure to do so thoroughly can result in drug shortages of essential medicines. Recently, the effects of COVID-19 exacerbated flaws in the current system causing the pharmaceutical industry and government organizations and to reassess relief strategies that could also strengthen the supply chain. Flow chemistry has become an attractive and prominent platform enabling continuous manufacturing (CM) technologies to synthesize active pharmaceutical ingredients (API) quickly according to demand. Compared to traditional batch chemistry, flow chemistry has demonstrated to be more robust in terms of throughput, scalability, and hazard reduction while maintaining a high degree of control and product quality. This work demonstrates these capabilities in reaction optimization and discovery with the overarching goal of domesticating CM to make essential medicines more affordable. A two-step process for the synthesis in diazepam was developed using a Chemtrix Labtrix S1 and Start microfluidic systems where purities as high as 98% were achieved. The system was successfully scaled up to a larger system that was able to produce 96% pure diazepam at a 91% yield. </p>
67

Performance and Subjective Effects of Diazepam and D-Amphetamine in High and Low Sensation Seekers

Kelly, Thomas H., Delzer, Timothy A., Martin, Catherine A., Harrington, Nancy G., Hays, Lon R., Bardo, Michael T. 01 September 2009 (has links)
Although sensation-seeking status is associated with age of initiation and amount of drug use among adolescents, and sensitivity to the behavioral and reinforcing effects of drugs among young adults, it is unclear whether sensation-seeking status among adolescents is predictive of sensitivity to the pharmacological effects of drugs (i.e. abuse potential) as adults. This study examined the acute behavioral effects of oral diazepam and d-amphetamine in young adults, ages 18-21 years, who had consistently scored in the highest or lowest third of their grade-based cohort on a modified Sensation Seeking Scale that was completed annually between ages 10 and 14 years. Healthy participants completed 16 7.5-h test days, with test days separated by a minimum of 48 h. Each day, assessments consisting of computer task performance, verbal report of drug effects, and cardiovascular measures were completed 0, 50, 110, 170, 230, and 290 min after drug administration. Placebo and three active doses of diazepam and d-amphetamine (2.5, 5.0 and 10.0 mg/70 kg) were tested under double-blind conditions according to a randomized-block design. Typical stimulant and sedative effects were obtained with d-amphetamine and diazepam, respectively. Drug effects varied as a function of sensation-seeking status, with magnitude of effects on cardiovascular function, task performance, and report of positive drug effects being greater among high sensation seekers, and report of negative drug effects being greater among low sensation seekers. Adolescents who report high levels of sensation seeking on a consistent basis are more sensitive to pharmacological effects of stimulant and sedative drugs that are associated with abuse potential as young adults.
68

Intra-vaginal Diazepam for High Tone Pelvic Floor Dysfunction: A Randomized Placebo-Controlled Trial

Crisp, Catrina C., M.D. 11 October 2013 (has links)
No description available.
69

Zur Nah-infrarot-Spektroskopie bei Hund und Katze - Experimentelle und klinische Untersuchungen zur perioperativen Überwachung sowie zu den Auswirkungen der Anästhesie auf den zerebralen Sauerstoffstatus

Alef, Michaele 24 October 2006 (has links) (PDF)
Die Nah-infrarot-Spektroskopie (NIRS) bestimmt kontinuierlich und nicht-invasiv anhand der Absorptionsänderung von nah-infrarotem Licht den Oxy- und Desoxyhämoglobingehalt sowie den Redoxstatus von Cytochrom a/a3 im Gewebe. Veränderungen von zerebralem Oxy- und Desoxyhämoglobingehalt und der daraus abgeleiteten Parameter reflektieren vor allem den venösen Sauerstoffstatus des Gehirns. Sie können ein früher und sensitiver Indikator für eine zerebrale Hypoxie sein. Der Redoxzustandes von Cytochrom a/a3 gibt als Korrelat des zerebralen Energiezustandes Hinweise auf ein kritisches Sauerstoffdefizit. Ziel der Untersuchung. In der experimentellen und klinischen Studie sollten mit einem kommerziell erhältlichen Gerät die Eignung der NIRS zur Überwachung des zerebralen Sauerstoffstatus während Anästhesie und Intensivtherapie bei Hund und Katze, die Messqualität, die auftretenden technischen Probleme und die darstellbaren Ereignisse geprüft werden. In der experimentellen Studie sollten die Veränderungen der zerebralen Oxygenierung und des Redoxzustandes von Cytochrom a/a3 nach verschiedenen zur Narkoseeinleitung beim Hund etablierten Protokollen sowie nach deren Antagonisierung ebenso untersucht werden wie der Zusammenhang der mittels NIRS erfassten Parameter mit denen des pulmonalen Gaswechsels und der Herz-Kreislauf-Funktion. Material und Methoden. In der klinischen Studie wurden Daten von 33 Hunden und 4 Katzen während Anästhesie oder Intensivüberwachung aufgezeichnet. Die experimentelle Studie wurde an 84 Foxhounds und 32 Beagle mit einem mittleren Alter von 12,96 Monaten (STD 13,42; 6,33–94,43 Monate) und einer mittleren Körpermasse von 24,76 kg (STD 6,6; 12,7–43 kg) durchgeführt, die zufällig auf vier Versuchsgruppen verteilt wurden. Die Sensorapplikation erfolgte in beiden Studien in Höhe der Ohrbasis auf geschorener Haut. Versuchsgruppen und –ablauf der experimentellen Studie: Gruppe Acepromazin/l-Methadon(AM): Narkoseeinleitung 0,1 mg/kg KM Acepromazin und 0,5 mg/kg KM l-Methadon i.v., keine weitere Erhaltung Gruppe Diazepam/l-Methadon(DM): 0,5 mg/kg KM Diazepam und 0,5 mg/kg KM l-Methadon i.v., keine weitere Erhaltung Gruppe Medetomidin/l-Methadon(MM): 40 mikrog/kg KM Medetomidin und 0,5 mg/kg KM l-Methadon i.v., keine weitere Erhaltung Propofol(P): Einleitung 0,1 mg/kg KM Propofol i.v., Erhaltung in dieser Gruppe 0,3 mg/kg/min Propofol i.v. In den Gruppen AM, DM und MM Antagonisierung 8 mikrog/kg KM Naloxon i.v. 30 min nach Einleitung, in der Gruppe MM zusätzlich 200 mikrog/kg KM Atipamezol i.v. 5 min später Kontinuierliche Überwachung von Herzfrequenz, EKG, Temperatur, invasiver Blutdruck,Pulsoxymetrie, Nah-infrarot-Spektroskopie. Blutgasanalyse 0, 5, 10, 15, 20, 25, 30 min nach Einleitung, 0, 2, 7 min nach Antagonisierung/Propofol-Ende Ergebnisse. Die Nah-infrarot-Spektroskopie ist prinzipiell bei Hund und Katze anwendbar, nicht jedoch bei schwarzhaarigen Tieren. Hauptprobleme sind Sensorbefestigung, Bewegungsartefakte und mangelnde Signalqualität. In der experimentellen Studie besteht im Mittel zu 80 % der ausgewerteten Zeit eine gute Messqualität. 14 % der Messungen sind ohne Störung, bei 17 % tritt in mehr als 50 % der Messzeit eine Störmeldung auf. Vor Narkoseeinleitung beträgt die regionale zerebrale Sauerstoffsättigung etwa 65 % (n=109, STD 7 %). Schon 1 Minute nach Einleitung bestehen signifikante Gruppenunterschiede. In Gruppe P steigt die zerebrale regionale Sauerstoffsättigung um etwa 8 %, sie fällt in Gruppe AM um 5 %, in Gruppe DM um bis zu 10 %, in Gruppe MM um maximal 20 % auf etwa 48 %, im weiteren Verlauf verweilt sie annähernd auf diesem Niveau. Zerebraler Oxy- und Desoxyhämoglobingehalt verhalten sich entsprechend. Der zerebrale Gesamthämoglobingehalt zeigt keine Gruppenunterschiede. Nach Antagonisierung erfolgt eine Änderung auf die Ausgangswerte vor Narkose ebenso prompt. Narkoseeinleitung und Antagonisierung haben keinen Effekt auf den Redoxzustand von Cytochrom a/a3. Korrelationen der zerebralen Oxygenierung mit arteriellem Sauerstoffstatus und Kohlendioxidpartialdruck bestehen. Eine periodische Atmung und eine Erhöhung des intraabdominellen Drucks spiegeln sich in parallelen Schwankungen der NIRS-Parameter wider. Die Auswirkungen von wechselnder Narkosetiefe, Erwachen, Hypoxie, Hyperventilation, Adrenalin, Pentobarbital, Herz-Kreislauf-Stillstand auf die NIRS-Parameter können dargestellt werden. Bewegungsartefakte stören häufig die Überwachung von Intensivpatienten. Bei Hunden mit Schädel-Hirn-Trauma ist die Signalqualität der limitierende Faktor. Diskussion. Die Nutzung eines für die Anwendung am Menschen bestimmten Gerätes bedingt aufgrund des spezifischen Weglängenfaktors einen Fehler unbekannter Bedeutung. Die zerebrale Messung konnte gesichert werden, der mögliche extrazerebrale Signalanteil bleibt unbekannt. Die nicht mögliche Nutzung bei schwarzen Tieren und die Artefaktanfälligkeit schränken den Wert der NIRS ein. Die ermittelten Störindizes sind stark methodisch beeinflusst, so dass ihre Beurteilung kritisch erfolgen sollte. Die NIRS ist geeignet, die durch Narkoseeinleitung und Antagonisierung beim Hund verursachten Veränderungen der zerebralen Oxygenierung aufzuzeigen. Eine Abnahme der regionalen zerebralen Sauerstoffsättigung um etwa 20 % (Gruppe MM) über die gesamte Messdauer scheint von klinischer Relevanz. Werte in dieser Höhe werden als Indiz einer kritischen zerebralen Sauerstoffversorgung beurteilt. Parallele Verläufe, positive Zusammenhänge mit dem arteriellen Sauerstoffstatus und negative zum Kohlendioxidpartialdruck zeigen ebenso wie die Effekte der Antagonisierung den entscheidenden Einfluss der Anästhetikabedingten Atemdepression auf den vaskulären zerebralen Sauerstoffstatus. Die mangelnde Reduktion von Cytochrom a/a3 deutet auf das Fehlen einer Störung der intrazellulären Sauerstoffversorgung hin. Die Reaktion der NIRS-Parameter auf eine Narkosekomplikation erfolgt schnell, jedoch unspezifisch, eine Interpretation ist nur in Zusammenhang mit anderen Parametern möglich. Die Beurteilung des Redoxzustandes von Cytochrom a/a3 erscheint schwierig, messtechnische Probleme sind nicht ausgeschlossen. Trotz aller messtechnischen und anwendungsbedingten Probleme wird die NIRS als Bereicherung der Überwachungsmöglichkeiten bei Hund und, sehr eingeschränkt, auch bei der Katze beurteilt. Sie eröffnet erstmals die Möglichkeit, die Auswirkungen von in der klinischen Routine eingeführten Verfahren auf die zerebrale Oxygenierung darzustellen. / ON NEAR-INFRARED-SPECTROSCOPY IN DOG AND CAT - EXPERIMENTAL AND CLINICAL STUDY ON PERIOPERATIVE MONITORING AS WELL AS EFFECTS OF ANAESTHESIA ON CEREBRAL OXYGEN STATUS Alef, Michaele Department of Small Animal Medicine, Faculty of Veterinary Medicine, University of Leipzig Habilitation thesis, 4. Dezember 2002 Near-Infrared-spectroscopy (NIRS) is a method to determine continuously and non-invasively the content of oxy- and deoxyhemoglobin as well as the redox status of cytochrome a/a3 in tissue via absorption changes of near-infrared light. Variations in cerebral content of oxy- and deoxyhemoglobin and parameters derived thereof reflect above all the venous oxygen status of the brain and may thus serve as an early and sensitive indicator of cerebral hypoxia. The redox status of cytochrome a/a3 correlates with the cerebral energy status and may thus serve as an indicator of a critical oxygen deficit. Aim of the study. The study was aimed at assessing in dogs and cats the suitability of NIRS and of an equipment used in human medicine for monitoring the cerebral oxygen status during anaesthesia and intensive therapy. The quality of the measurements, technical problems and the achievable results should be critically checked in experimental and clinical situations. Changes of cerebral oxygenation and of the redox status of cytochrome a/a3 with different established protocols of anaesthesia in dogs and after antagonising had to be investigated in the experimental study as well as well as relationships between parameters obtainable with NIRS and those of pulmonary gas exchange and cardiovascular function. Materials and methods. During the clinical study data from 33 dogs and 4 cats were recorded during anaesthesia and intensive supervision. The experimental investigations were performed with 84 foxhounds and 32 Beagles with a mean age of 12,96 months (STD 13,42; range 6,33–94,43) and a mean weight of 24.76 kg (STD 6.6, range 12.7–43), which were distributed at random into four experimental groups. Sensors were applied near the ear base on shaved skin. Experimental groups and design. Group Acepromazine/l-Methadone(AM): INduction 0.1 mg/kg BW Acepromazine and 0.5 mg/kg BW l-Methadonr i.v., no additional maintenance Group Diazepam/l-Methadone(DM): 0.5 mg/kg BW Diazepam and 0.5 mg/kg BW l-Methadone i.v., no additional maintenance Group Medetomidine/l-Methadone(MM): 40 mikrog/kg BW Medetomidine and 0.5 mg/kg BW l-Methadone i.v., no additional maintenance Group Propofol(P): Induction 0.1 mg/kg BW Propofol i.v., Maintenance 0.3 mg/kg/min Propofol i.v. In groups AM, DM und MM antagonization of the opioide with 8 mikrog/kg BW Naloxone i.v. 30 min after induction, in group MM 200 mikrog/kg BE Atipamezole i.v. 5 min later Continuos Monitoring of heart rate, ECG, temperature, invasive blood pressure,pulse oxymetry, near-infrared-spectroscopy. Blood gas analysis 0, 5, 10, 15, 20, 25, 30 min post induction and 0, 2, 7 min post Naloxone/end of infusion. Results. NIRS is in principle applicable in dogs and cats but not, however, in black-haired animals. The main problems are the application of the sensor, movement artefacts and poor quality of the measurement signals. In the experimental study good measurement quality could be obtained in on average 80% of the investigation time, 14% of the recordings are without disturbance, in 17% disturbances are recorded in more than 50% of the investigation time. Before the start of anaesthesia the regional cerebral oxygen saturation amounts to about 65% (n=109, STD 7%). Already one minute after the beginning of anaesthesia significant differences between groups are found: In group P the regional cerebral oxygen saturation increases by about 8% while it decreases in group AM by 5%, in group DM by up to 10% and in group MM by maximally 20% to a value of about 48% where it remains roughly during the following time. Cerebral oxy- and deoxyhemoglobin content display an analogous behaviour. There are no inter-group differences in total cerebral hemoglobin content. After antagonising the initial values before the start of anaesthesia are rapidly attained again. Start of anaesthesia and antagonising do not show any influences on the redox status of cytochrome a/a3 while there are correlations between the cerebral oxygenation and the arterial oxygen status and the partial pressure of carbon dioxide. Periodic breathing and an increase of the intra-abdominal pressure are mirrored by variations of the NIRS-parameters, The effects of changing depth of anaesthesia, waking up, hypoxia, hyperventilation, adrenaline, pentobarbital and circulatory arrest can be demonstrated by the NIRS-parameters. Movement artefacts frequently interfere with the monitoring of intensive patients. The signal quality is frequently not sufficient in dogs with severe head trauma. Discussion. The direct application of factors established in humans leads to poorly defined errors. For cerebral measurements the applicability of the method could be confirmed, the possible contribution of extracerebral signals, however, remains unknown. The fact that black-haired animals cannot be investigated and proneness to artefacts limit the value of NIRS. Determined disturbance indices depend strongly on the methods used and should be seen critically. NIRS is suitable to give an indication of changes of cerebral oxygenation caused by the start of anaesthesia and antagonising. A decrease of about 20% in the regional cerebral oxygen saturation during the total measurement time (group MM) appears to be of clinical relevance. Values in this range are taken to be indicative of a critical cerebral oxygen supply. Parallelisms and positive correlations with the arterial oxygen status as well as negative correlations with carbon dioxide partial pressure and the effects of antagonising demonstrate the decisive influence of anaesthesia-related depression of breathing on the vascular cerebral oxygen status. The lack of cytochrome a/a3 reduction indicates that the intracellular oxygen supply is not disturbed. The reaction of NIRS-parameters on the start of anaesthesia is fast, but unspecific, and a meaningful interpretation is only possible in conjunction with other parameters. The evaluation of cytochrome a/a3 redox status appears to be difficult, and technical problems with the measurement cannot be excluded. In spite of these limitations in terms of measurements and applicability NIRS can be judged as a valuable addition for the clinical observation of dogs, less so with cats. The method opens for the first time the possibility to monitor the influence of clinical routines on cerebral oxygenation.
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Transfer kroz fetoplacentarnu membranu i farmakokinetika lekova u premedikaciji kod elektivnih carskih rezova / Transfer through transplacental membrane and pharmacokinetics of drugs in premedication for elective caesarean sections

Paunković Jovana 31 October 2014 (has links)
<p>Uprkos op&scaron;te prihvaćenom stavu da u trudnoći lekove treba izbegavati, veliki broj trudnica tokom trudnoće uzima lekove sa manje ili vi&scaron;e opravdanja. Primena lekova u trudnoći zahteva dodatnu patnju, jer se mora voditi računa o zdravlju majke i zdravlju jo&scaron; nerođenog&nbsp; deteta. Većina lekova koji nalaze primenu u trudnoći, nisu ispitani u kontrolisanim studijama na trudnicama, već se njihov uticaj naljudski fetus, bazira na predpostavkama i kliničkim istraživanjima na životinjama. Odsustvo studija dovodi do toga da se trudnicama obično prepisuju lekovi u dozi za odrasle osobe, koje ne prate fiziolo&scaron;ke promene u trudnoći. Tokom trudnoće u telu trudnica dolazi do promena u funkciji organa i organskih sistema, a zbog nastalih promena menja se i sudbina leka u organizmu. Sistemske bolesti trudnice poput hipertenzije i dijabetesa dovode do hemodinamskih promena i utiču na nastanak patolo&scaron;kih promena posteljice, &scaron;to sve zajedno menja farmakokinetiku lekova i njihov transplacentrarni transport. Ukupno 75 trudnica je uključeno u studiju i podeljeno u tri grupe: zdrave trudnice-kontrolna grupa (n=31), trudnice sa hipertenzijom (n=30) i trudnice sa dijabetesom (n=14). Sve trudnice su u premedikaciji primile iste lekove koji su deo standardne kliničke&nbsp; procedure. Trudnice su primile jednu dozu diazepama intramuskularnom injekcijom (10mg/2ml), a intravenski su primile pojedinačne doze cefuroksima (1,5g), metoklopramida (10mg/2ml) i ranitidina (50mg/2ml). Od svakog para majka-dete ukupno je analizirano po 5 uzoraka. Uzorci krvi od majke uzimani su u tri vremenske tačke: nakon davanja leka, u momentu ekstrakcije deteta i nakon porođaja. Uzorci&nbsp; krvi&nbsp; deteta&nbsp; uzimani su&nbsp; nakon&nbsp; porođaja iz pupčane vene i arterije. Prikupljeni uzorci plazme analizirani su metodom tečne hromatografije visokih performansi (HPLC). Istraživanje je pokazalo da lekovi&nbsp; primenjeni u premedikaciji&nbsp; carskog reza prolaze transplacentarnu membranu i da se ni jedan&nbsp; od&nbsp; lekova&nbsp; primenjenih&nbsp; u studiji nije akumulirao u fetusu i nije imao neželjeno dejsvo na novorođenče. Cefuroksim, ranitidin i metoklopramid pokazali su nizak feto-maternalni transfer, dok je diazepam pokazao visok&nbsp; feto-maternalni transfer. Izmerene koncentracije cefuroksima u plazmi trudnica u momentu porođaja bile su &ge;8 &mu;g/ml, &scaron;to je koncentracija veća od MIC za većinu patogena odgovornih za nastavak infekcija u aku&scaron;erstvu. Koncentracije cefuroksima u fetalnoj plazmi bile su &ge;4&mu;g/ml &scaron;to je veće od&nbsp; MIC koncentracija za veliki broj patogena. Gestacijska starost trudnoće nije uticala na obim prolaska cefuroksima&nbsp; kroz placentu, koji je prolazi uglavnom pasivnom difuzijom. Farmakokinetski parametri cefuroksima razlikovali su se kod hipertenzivnih i dijabetičnih trudnica, u odnosu kontrolnu grupu, ali ove bolesti nisu imale značajan uticaj na smanjenje terapijske efikasnosti cefuroksima. Farmakokinetika cefuroksima kod hipertenzivnih&nbsp; trudnica&nbsp; ukazala je na bržu eliminaciju cefuroksima iz krvi majke i na veću distribuciju leka u okolna tkiva. U dijabetičnoj grupi trudnica i novorođenčadi koncentracije cefuroksima su bile vi&scaron;e u odnosu na druge ispitivane grupe, dok je feto-maternalni odnos bio niži, &scaron;to ukazuje na postojanje strukturalne i funkcionalne pomenu posteljice u dijabetesu. Hipertenzija i dijabetes trudnica nisu imali uticaj na prodor ranitidina kroz placentu. Hipertenzija i dijabetes trudnica nisu uticali na većinu farmakokinetskih parametara ranitidina, mada je zabeleženo smanjenje volumena distribucije u ovim grupama trudnica, &scaron;to bi moglo da ukazuje na njihovu hemodinamsku nestabilnost i povećanje slobodne frakcije ranitidina. Koncentracija metoklopramida bila veća u krvi majki u odnosu na krv fetusa. Transport metoklopramida iz fetusa ka majci bio je dominantniji, a naročito u hipertenzivnoj i dijabetičnoj grupi trudnica. Hipertenzija i dijabetes trudnica uticali su na zadržavanje metoklopramida u fetusu. Koncentracije dijazepama u majčinoj i fetalnoj krvi bile su vi&scaron;e u kontrolnoj i hipertenzivnoj grupi trudnica. Hipertenzija i dijabetes trudnica povećavaju&nbsp; transfer diazepama kroz placentu, povećanjem koncentracije slobodnih masnih kiselina, steroidnih hormona, smanjenjem vezivnog kapaciteta potencijalna opasnost od neželjenog dejstva diazepama i njegovih metabolita na fetus i novorođenče. Ova doktorska studija ukazuju na potrebu obimnijih farmakokinetskih istraživanja kako na zdravim tako i na bolesnim trudnicama, koja će dati zaključke utvrđene na dokazima i pomoći u individualnom terapijskom pristupu svakoj trudnici.</p> / <p>In spite of&nbsp; the widespread opinion&nbsp; that&nbsp; drugs should be avoided in pregnancy, a great number of&nbsp; pregnant&nbsp; women&nbsp; take drugs with more or less justification.&nbsp; Administration of drugs in pregnancy requires additional attention because the health of&nbsp; both the mother and&nbsp; her unborn child must be protected. Majority of drugs administered in pregnancy have not been tested&nbsp; within the controlled studies performed on pregnant women, but&nbsp; their effect on the human foetus is based on assumptions and clinical trials performed on animals. This absence of studies results in the situation that pregnant&nbsp; women are usually prescribed drugs in a dose&nbsp; for adults, which does not take into account the physiological changes happening in pregnancy. During pregnancy, the pregnant woman&rsquo;s body undergoes changes in the<br />functions of organs and organ systems. These changes further affect the destiny of a&nbsp; drug in the organism. In pregnant women, systemic diseases such as hypertension&nbsp;&nbsp; and diabetes mellitus lead to hemodynamic changes and cause pathological&nbsp; changes in placenta, thus changing the pharmacokinetics of drugs and their transplacental transport. The study sample consisted of 75 pregnant women, who were divided into three groups as follows: the control group included healthy pregnant&nbsp; women (n=31), a group of pregnant women&nbsp; with&nbsp; hypertension (n=30) and&nbsp; a group of&nbsp; those&nbsp; with&nbsp; diabetes mellitus (n=14). All of them were administered the same drugs as a part of standard clinical procedure in premedication. The pregnant women received a single dose of diazepam by intramuscular injection (10mg/ml), and individual doses of cefuroxime (1.5mg), metoclopramide (10mg/2ml) and ranitidine (50mg/2ml). Five samples taken from each mother-infant pair were analyzed. Blood samples were taken from the mother three times: after drug administration, at the moment of extraction of baby and after delivery. Baby&rsquo;s blood samples were taken from the umbilical cord vein and artery after delivery. Plasma samples were analyzed by the method of high-performance liquid chromatography (HPLC). The research has shown that drugs administered in premedication of caesarean section went through the transplacental membrane and that none of the tested drugs accumulated in the foetus and had an adverse effect on the newborn. Cefuroxime, ranitidine and metoclopramide were shown to have a low transfer between the mother and her foetus, whereas diazepam showed a high foetal-maternal transfer. Cefuroxime concentrations measured in the pregnant woman&rsquo;s and foetal plasma at the moment of delivery were &ge;8&mu;g/ml and &ge;4&mu;g/ml, respectively, that&nbsp; being above the minimum inhibitory concentration (MIC) for most pathogens responsible for the development of infection in obstetrics. Gestational age had no effect on the range of cefuroxime flow through the placenta, which happens mostly by&nbsp; passive diffusion. Pharmacokinetic parameters of cefuroxime differed in the pregnant&nbsp; women having hypertension and diabetes mellitus from the controls; however, these diseases did not significantly reduce the therapeutic efficacy of cefuroxime. Pharmacokinetics of cefuroxime indicated faster elimination of&nbsp; cefuroxime into the maternal blood and greater distribution of the drug into the surrounding tissues in the hypertensive pregnant women. In the group consisting of pregnant women and newborns having diabetes, the cefuroxime concentrations were higher than in other groups, whereas foetal-maternal relation was lower, which suggests the presence of structural and functional change in the placenta in diabetes. Hypertension and diabetes mellitus had no affect either on the flow of ranitidine through the placenta in the pregnant women or on&nbsp; the&nbsp; majority of pharmacokinetic parameters of ranitidine, although a certain reduction in the volume&nbsp; of distribution was recorded in these groups of pregnant women, which could suggest their hemodynamic instability and increased free fractions of ranitidine. The concentration of metocloporamide was higher in the maternal blood than in the&nbsp; foetal blood, and&nbsp; the transport of metocloporamide from the foetus towards the mother was more dominant, particularly in&nbsp; the&nbsp; group of&nbsp; hypertensive and diabetic&nbsp;&nbsp;&nbsp; pregnant women. Metoclopramide tended to retain in the foetuses of mothers having&nbsp; hypertension and diabetes. The concentrations of diazepam in maternal and foetal blood were higher in the controls&nbsp; and hypertensive&nbsp; pregnant&nbsp; women. Hypertension and diabetes in pregnant&nbsp; women increase the transfer of diazepam through the placenta by increasing the concentration of free fatty acids and steroid hormones and by reducing the binding capacity of carrier proteins and the concentration of plasma&nbsp;&nbsp; proteins, thus increasing the potential danger of adverse effects of diazepam and its metabolites on the foetus and the newborn. This doctoral study suggests the necessity for more extensive pharmacokinetic research including both healthy and affected pregnant women that would lead to conclusions based on evidence and help to develop individual therapeutic approach to each pregnant woman.</p>

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