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NeurotoxinsKostrzewa, R. M. 01 January 2009 (has links)
A selective neurotoxin takes many forms: as an antibody to a neurotrophin, as an alkylator, as an excitotoxin, as a blocker of requisite neuronal excitation during ontogenetic development, as a generator of oxidative stress, as an inhibitor of vital intraneuronal processes, and as an agent adversely affecting a host of multiple sites in neurons. Neurotoxins have been invaluable for elucidating cellular mechanisms attending or preventing neuronal necrosis and apoptosis, and for modeling and thereby discerning mechanisms invoked in neurological and psychiatric disorders. Neuroprotectants, endogenous and exogenous, are being explored as potentially useful agents to ward off diseases. Finally, hypothesized as posing a risk to humans as environmental constituents, neurotoxins are now being remodeled as adjuncts for therapeutic intervention in a variety of human medical disorders.
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A Multi-Level Analysis of Amphetamine Derivatives: Repeated 3,4-Methylenedioxymethamphetamine Administration and Popular Methamphetamine Combinations in Mice and HumansMedina-Kirchner, Christopher Michael January 2024 (has links)
Despite decades of research on amphetamine derivatives, a class of compounds sharing a structural foundation with amphetamine, crucial gaps remain in our understanding of these drugs in a variety of animal species and humans.
This dissertation addresses three of these gaps through a multi-level approach involving studies in both humans and mice. Specifically, it focuses on investigating the lack of information regarding: 1) repeated dosing of 3,4-methylenedioxymethamphetamine in humans, 2) methamphetamine/alcohol combinations in humans and 3) methamphetamine/oxycodone combinations in mice.
Study 1 involved administering three consecutive doses of 3,4 methylenedioxymethamphetamine to human volunteers at 12- and 24-hour intervals while physiological, behavioral, and subjective measures were collected. Study 2 reanalyzed Kirkpatrick and colleagues (2012a) data to evaluate repeated administrations of methamphetamine and alcohol. The reanalysis focused on quantifying the physiological and subjective effect differences between the first and second administrations, which occurred at a 12-hour interval on the same day, an aspect not previously analyzed or reported by the original authors. Study 3 utilized well-established animal models such as Conditioned Place Preference, Open Field Test, and Novel Object Recognition to evaluate the reward-like and aversive effects of methamphetamine and oxycodone combinations in mice. Study 1 was the first to quantify the effects of multiple 3,4-methylenedioxymethamphetamine doses administered over a 36-hour period of time. Initially, acute
3,4-methylenedioxymethamphetamine produced dose-dependent increases in peak heart rate, blood pressure, and more positive than negative subjective effects. However, by the third dose, many of these effects dissipated, heart rate was no longer elevated, and residual mood effects were minor.
Overall, the data do not support the general perception that
3,4-methylenedioxymethamphetamine produces dangerous cardiovascular and residual mood effects in humans following repeated administration. The results of Study 2, again a first in the field, discovered that contrary to expectations, heart rate increases produced by the methamphetamine/alcohol combination were not further increased with repeated dosing, but rather attenuated. In fact, methamphetamine offset alcohol-induced intoxication, even after repeated administration. Study 3 revealed that combining methamphetamine and oxycodone in mice increased reward as measured by Conditioned Place Preference, but not more than either drug alone.
However, methamphetamine lengthened the duration of Conditioned Place Preference for the lower oxycodone dose and offset the oxycodone-induced disruptions in novel object recognition performance. One crucial cross-species observation was that methamphetamine mitigated adverse effects such as alcohol-related intoxication and oxycodone cognitive disruption, even after repeated administration. While seemingly beneficial, this observation raises concerns that individuals who combine these drugs may be at risk of underestimating their overall degree of impairment, potentially leading to hazardous activities like driving while intoxicated or engaging in risky behaviors. Sharing this insight is crucial to encourage informed, responsible behavior and safeguard public safety.
In conclusion, these studies have significantly enhanced our understanding of two frequently used amphetamine derivatives and their interactions with two commonly used psychoactive drugs—oxycodone and alcohol. Most importantly, we strongly advocate for robust empirical experimentation to counteract misinformation related to 3,4-methylenedioxymethamphetamine and methamphetamine. These endeavors are crucial for developing more precise assessments of the risks and benefits associated with these substances, and for improving drug policies and optimizing public health interventions.
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Comprehensive two-dimensional gas chromatography (GCxGC ) for drug analysisSong, Shin Miin, shinmiin@singnet.com.sg January 2006 (has links)
Separation technologies have occupied a central role in the current practices of analytical methods used for drug analysis today. As the emphasis in contemporary drug analysis shifts towards ultra-trace concentrations, the contribution from unwanted matrix interferences takes on greater significance. In order to single out a trace substance with confidence from a rapidly expanding list of drug compounds (and their metabolites) in real complex specimens, analytical technologies must evolve to keep up with such trends. Today, the task of unambiguous identification in forensic toxicology still relies heavily upon chromatographic methods based on mass spectrometric detection, in particular GC-MS in electron ionisation (EI) mode. Although the combined informing power of (EI) GC-MS has served faithfully in a myriad of drug application studies to date, we may ask if (EI) GC-MS will remain competitive in meeting the impending needs of ultra-trace drug analysis in the fut ure? To what extent of reliability can sample clean-up strategies be used in ultra-trace analysis without risking the loss of important analytes of interest? The increasing use of tandem mass spectrometry with one-dimensional (1D) chromatographic techniques (e.g. GC-MS/MS) at its simplest, considers that single-column chromatographic analysis with mass spectrometry alone is not sufficient in providing unambiguous confirmation of the identity of any given peak, particularly when there are peak-overlap. Where the mass spectra of the individual overlapping peaks are highly similar, confounding interpretation of their identities may arise. By introducing an additional resolution element in the chromatographic domain of a 1D chromatographic system, the informing power of the analytical system can also be effectively raised by the boost in resolving power from two chromatographic elements. Thus this thesis sets out to address the analytical challenges of modern drug analysis through the application of high resolut ion comprehensive two-dimensional gas chromatography (GCeGC) to a series of representative drug studies of relevance to forensic sciences.
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The amphetamine years: a study of the medical applications and extramedical consumption of psychostimulant drugs in the postwar united states, 1945-1980Moon, Nathan William 16 November 2009 (has links)
The Amphetamine Years is a history of psychostimulant drugs and their clinical applications in post-World War II American medicine. Comprising such well-known substances as the amphetamines (Benzedrine, Dexedrine), methylphenidate (Ritalin), and phenmetrazine (Preludin), this class of pharmaceuticals has been among the most widely consumed in the past half-century. Their therapeutic uses for a variety of indications such as depression, obesity, and attention-deficit/hyperactivity disorder (ADHD) in children, not to mention their relevance for a number of different medical specialties, reveals that psychostimulants have occupied an important, if underappreciated role in the practice of modern medicine. In this dissertation, I illuminate the various ways in which physicians, particularly psychiatrists, put these drugs to work in clinical practice. In short, I contend that physicians exploited the wide range of physiological and psychological effects of psychostimulants and made a place for them in different therapeutic settings, even ones characterized by competing views and theories about the workings of the human body and mind.
My dissertation is distinguished by two prominent themes. First, I emphasize the clinician perspective as a vehicle for understanding the history of the psychostimulants, as well as related developments in psychiatry, pharmacotherapy, and the political economy of drugs, in the second half of the twentieth century. Scholars such Nicolas Rasmussen, David Courtwright, and Ilina Singh have elucidated the history of psychostimulants by emphasizing how pharmaceutical companies positioned their products in the medical marketplace. My dissertation takes a different, yet complimentary approach by studying clinicians, themselves, to further historical comprehension of the place of these pharmaceuticals within postwar medicine, society, and culture. Second, I advance the concept of "therapeutic versatility" to explain their historical trajectories. The complex set of psychological and physical effects these drugs produced made them ideal for a diverse range of therapeutic applications, which explains why they were embraced by many different medical specialties, why they were marketed by manufacturers for a variety of indications, and why they have enjoyed an enduring therapeutic lifespan, in spite of increasing efforts since the mid-1960s to regulate their availability and control their consumption. In addition to these two overarching themes, I advance five specific arguments in my dissertation. First, I contend that pharmaceutical markets were simultaneously created by the drug industry and clinicians. Pharmaceutical firms' efforts to develop markets for their products have been well documented by historians, but in my dissertation, I underscore the role also played by clinicians in discerning drugs' applications. Second, I argue that twentieth-century psychiatry's conception of illness and therapeutics may not be served best by strictly dividing its history along lines of institutional and outpatient treatment. Third, I demonstrate how the use of psychostimulants by analytically oriented psychiatrists during the 1950s complicates historical notions of paradigm shift from a psychodynamic to biological orientation. Psychotherapy and psychopharmacology were not competing paradigms; in practice, doctors often employed both. Fourth, I assert that an appreciation of psychiatrists' empirical and eclectic approaches to the use of drugs is necessary to comprehend the rise of psychiatric pharmacotherapy in the postwar era. Finally, I contend that in order to understand the relationship between medical applications of psychostimulants and their extramedical consumption, it is necessary to conceive of a plurality of distinct "amphetamine cultures," each characterized by a unique set of relationships between physician-prescribers, patient-consumers, pharmaceutical firms, and political authorities.
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Neurotoxins and Neurotoxicity Mechanisms. An OverviewSegura-Aguilar, Juan, Kostrzewa, Richard M. 01 December 2006 (has links)
Neurotoxlns represent unique chemical tools, providing a means to 1) gain insight into cellular mechanisms of apopotosis and necrosis, 2) achieve a morphological template for studies otherwise unattainable, 3) specifically produce a singular phenotype of denervation, and 4) provide the starting point to delve into processes and mechanisms of nerve regeneration and sprouting. There are many other notable uses of neurotoxins in neuroscience research, and ever more being discovered each year. The objective of this review paper is to highlight the broad areas of neuroscience in which neurotoxins and neurotoxicity mechanism come into play. This shifts the focus away from neurotoxins per se, and onto the major problems under study today. Neurotoxins broadly defined are used to explore neurodegenerative disorders, psychiatric disorders and substance use disorders. Neurotoxic mechanisms relating to protein aggregates are indigenous to Alzheimer disease, Parkinson's disease. NeuroAIDS is a disorder in which microglia and macrophages have enormous import. The gap between the immune system and nervous system has been bridged, as neuroinflammation is now considered to be part of the neurodegenerative process. Related mechanisms now arise in the process of neurogenesis. Accordingly, the entire spectrum of neuroscience is within the purview of neurotoxins and neurotoxicity mechanisms. Highlights on discoveries in the areas noted, and on selective neurotoxins, are included, mainly from the past 2 to 3 years.
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Central Nervous System Stimulants and Drugs That Suppress AppetiteBello, Nicholas T., Zahner, Matthew R. 01 January 2017 (has links)
The Side Effects of Drugs Annuals forms a series of volumes in which the adverse effects of drugs and adverse reactions to them are surveyed. The series supplements the contents of Meyler's Side Effects of Drugs: The International Encyclopedia of Adverse Drug Reactions and Interactions. The purpose of this supplement is to provide a concise reference of the newly available literature to support the existing information regarding the known adverse effects of commonly prescribed medications or abused drugs. The information covers peer-reviewed publications from January 2016 to December 2016. This review focused on CNS stimulants and drugs that suppress appetite. It covers amphetamines (including lisdexamfetamine, methamphetamine and 3,4-methylenedioxymetamphetamine), methylphenidate, atomoxetine, modafinil and armodafinil, methylxanthines (caffeine), monotherapies and combinational therapies that suppress appetite (lorcaserin, phentermine, phentermine/topiramate) and medications used in Alzheimer's disease and cognitive decline (rivastigmine, donepezil and memantine).
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Qualitat en l’anàlisi de drogues d’abús en cabell i en fluid oralVentura Alemany, Montserrat 16 December 2011 (has links)
The use of hair and oral fluid for drugs of abuse testing has increased over the last years. For this reason, the assurance that results provided using these matrices are reliable and error-free is needed. The objective of this thesis is to develop tools to assess the quality of results provided by laboratories analysing drugs of abuse in hair and in oral fluid and to evaluate the effect on the quality of results of different actions carried out. For this reason, intercomparison exercises have been organized and some studies have been performed to develop appropriate quality control materials.
Regarding the analysis of drugs of abuse in hair, nine different intercomparison exercises have been organized. The evaluation of qualitative and quantitative results reported by laboratories together with the study of the methodology used, has led to know the quality of the results, to identify the sources of error and to know the corrective actions that should be developed. Concerning the quality control material, these exercises have enabled to know the influence on the results of the type of hair used to perform the analysis.
Concerning the analysis of drugs of abuse in oral fluid, a method has been developed to identify and quantify 6-monoacetyl morphine, morphine, codeine, cocaine and benzoylecgonine in oral fluid samples. On the other hand, stability studies of the main drugs of abuse in oral fluid have been done to establish the optimal preparation, transport and storage conditions, and finally, two intercomparison exercises have been conducted to know the performance of analytical laboratories when analysing drugs of abuse in oral fluid and to know the stability of some drugs of abuse in two commercial collection devices. / La creixent utilització del cabell i del fluid oral per a l’anàlisi de drogues d’abús, ha portat a la necessitat d’assegurar que els resultats obtinguts utilitzant aquestes matrius són fiables i lliures d’error. L’objectiu d’aquesta tesi és desenvolupar eines que permetin avaluar la qualitat dels resultats dels laboratoris que analitzen drogues d’abús en cabell i en fluid oral i avaluar l’efecte de diferents accions sobre la qualitat final dels resultats. Per això s’han organitzat exercicis interlaboratori i s’han realitzat estudis per desenvolupar material d’assaig adequat.
Pel que fa a l’anàlisi de drogues d’abús en cabell, s’han realitzat nou exercicis interlaboratori. A través de l’avaluació dels resultats qualitatius i quantitatius informats pels laboratoris i mitjançant l’estudi de la metodologia emprada, ha estat possible conèixer la qualitat dels resultats obtinguts, detectar les fonts d’error i conèixer quines mesures correctives caldria desenvolupar. Pel que fa al material d’assaig, aquests exercicis han permès conèixer la influència que té, en els resultats, el tipus de cabell del qual es parteix per realitzar l’anàlisi.
Pel que fa a l’anàlisi de drogues d’abús en fluid oral, s’ha desenvolupat i validat un mètode analític que ha permès identificar i quantificar 6-monoacetil morfina, morfina, codeïna, cocaïna i benzoïlecgonina en mostres de fluid oral. Per altra banda, s’han realitzat estudis d’estabilitat de les principals drogues en fluid oral que han permès establir les condicions òptimes de preparació, transport i conservació del material d’assaig i, per últim, s’han realitzat dos exercicis interlaboratori que han permès conèixer la qualitat dels resultats analítics obtinguts pels laboratoris i també l’estabilitat de les drogues en dos dispositius de recollida comercials.
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Advances in Gas Chromatography and Vacuum UV Spectroscopy: Applications to Fire Debris Analysis & Drugs of AbuseZackery Ray Roberson (9708611) 07 January 2021 (has links)
In forensic chemistry, a quicker and more accurate analysis of a sample is always being pursued. Speedy analyses allow the analyst to provide quick turn-around times and potentially decrease back-logs that are known to be a problem in the field. Accurate analyses are paramount with the futures and lives of the accused potentially on the line. One of the most common methods of analysis in forensic chemistry laboratories is gas chromatography, chosen for the relative speed and efficiency afforded by this method. Two major routes were attempted to further improve on gas chromatography applications in forensic chemistry.<br> The first route was to decrease separation times for analysis of ignitable liquid residues by using micro-bore wall coated open-tubular columns. Micro-bore columns are much shorter and have higher separation efficiencies than the standard columns used in forensic chemistry, allowing for faster analysis times while maintaining the expected peak separation. Typical separation times for fire debris samples are between thirty minutes and one hour, the micro-bore columns were able to achieve equivalent performance in three minutes. The reduction in analysis time was demonstrated by analysis of ignitable liquid residues from simulated fire debris exemplars.<br> The second route looked at a relatively new detector for gas chromatography known as a vacuum ultraviolet (VUV) spectrophotometer. The VUV detector uses traditional UV and far-ultraviolet light to probe the pi and sigma bonds of the gas phase analytes as well as Rydberg traditions to produce spectra that are nearly unique to a compound. Thus far, the only spectra that were not discernable were from enantiomers, otherwise even diastereomers have been differentiated. The specificity attained with the VUV detector has achieved differentiation of compounds that mass spectrometry, the most common detection method for chromatography in forensic chemistry labs, has difficulty distinguishing. This specificity has been demonstrated herein by analyzing various classes of drugs of abuse and applicability to “real world” samples has been demonstrated by analysis of de-identified seized samples.<br>
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