Thesis (doctoral)--Lund University, 1997. / Added t.p. with thesis statement inserted.

Nanogels are soft, deformable networks of cross-linked polymer swollen in water. Nanogels have the unique ability to swell in response to external physiological conditions. Their stimuli-responsive nature affects degradability, drug uptake and release, which can be exploited to create tunable drug delivery systems. The ability to alter the composition and structure of nanogels imparts advantageous characteristics for targeted drug delivery applications. Antipsychotic drugs (APDs) used to treat schizophrenia, a chronic neuropsychiatric disorder, are typically hydrophobic. Prolonged dosing causes neurological and metabolic side effects due to the systemic administration of drug. Patient adherence to APD administration is low, causing complications that contribute to the substantial burden of disease. APDs would benefit from nanogel encapsulation through improved solubility and controlled release kinetics to reduce the adverse side effects associated with typical administration protocols. This thesis presents the development of hydrophobized, biodegradable poly(oligoethylene glycol methacrylate) (POEGMA)-based nanogels to deliver APDs to the brain. Both an adaptation of conventional precipitation polymerization as well as a spontaneous self-assembly technique are utilized to synthesize nanogels containing different hydrophobic domains. Incorporation of cross-linkers with different modalities of biodegradability enable stimuli-responsive degradation and drug release. The effects on nanogel swelling, biodegradability, and APD uptake and release kinetics are explored in vitro. The preclinical application of these APD-loaded nanogels is evaluated using the minimally invasive intranasal (IN) route for delivery. We show that these nanogel delivery systems have therapeutic effects in terms of significantly altering a range of rodent behaviours, including locomotion inhibition, the onset of catalepsy, and improvement in pre-pulse inhibition, over extended periods of time in relation to current administration strategies. These drug-loaded nanogel delivery systems show potential to minimize the effective therapeutic dose by enhancing APD bioavailability via IN administration, thus reducing adverse outcomes and improving potential patient adherence to APD-based therapies in clinical use. / Thesis / Doctor of Philosophy (PhD) / Nanogels are soft, deformable polymer networks swollen in water with potential for drug delivery given their easy-to-tune physicochemical properties. However, the poor water solubility of many therapeutics, including antipsychotic drugs (APDs) used to treat schizophrenia, limits drug encapsulation within nanogels. In addition, conventional synthetic techniques produce materials that degrade into poorly-defined byproducts, causing toxicity concerns. This thesis presents novel strategies to incorporate hydrophobic domains and biodegradable bonds within poly(oligo ethylene glycol methacrylate) (POEGMA) nanogels. We demonstrate how these moieties affect nanogel swelling, degradability, cytocompatability as well as the uptake and release of clinically prescribed APDs. Intranasal (IN) administration of drug-loaded nanogels is studied as a non-invasive delivery alternative to improve drug bioavailability. The proposed nanogel-based drug delivery systems can decrease drug dose, minimize adverse side effects, and improve patient adherence to therapeutic regimens relying on APDs, demonstrating their potential for clinical application.

The treatment of schizophrenia today consists of a multi-component system of services. Mental health professionals generally agree that anti-psychotic medications are an essential treatment for schizophrenia. However, adherence to medication regimens by patients with schizophrenia is notoriously poor. To identify correlates and predictors of medication compliance, the Schedule for Affective Disorders and Schizophrenia (SADS), a semi-structured diagnostic interview, was administered to 90 outpatients with schizophrenia. The results suggest that there are specific variables (i.e., mood symptoms, psychotic symptoms, and socio-demographic variables) that predict medication compliance. In addition, the confirmation of these variables was effective (90.0%) at identifying non-compliant patients. The results suggest that schizophrenia is a complex disorder composed of heterogeneous symptoms. However, a specific group of symptoms is proposed which may provide a screening measure for predicting patients who are likely to be non-compliant with their medications.

Aggression and violence pose a significant public health concern to society. Aggression is a highly conserved behavior that shares common biological correlates across species. While aggression developed as an evolutionary adaptation to competition, its untimely and uncontrolled expression is maladaptive and presents itself in a number of neuropsychiatric disorders. A mechanistic hypothesis for pathological aggression links aberrant behavior with heightened dopamine function. However, while dopamine hyper-activity is a neural correlate of aggression, the developmental aspects and circuit level contributions of dopaminergic signaling have not been elucidated. In this dissertation, I aim to address these questions regarding the specifics of dopamine function in a murine model of aggressive behavior. In chapter I, I provide a review of the literature that describes the current state of research on aggression. I describe the background elements that lay the foundation for experimental questions and original data presented in later chapters. I introduce, in detail, published studies that describe the clinical manifestation and epidemiological spread, the dominant categories, the anatomy and physiology, and the pharmacology of aggression, with a particular emphasis on the dopaminergic system. Finally, I describe instances of genetic and environmental risk factors impacting aggression, concluding with studies revealing an important role for interactions among genetics, environmental factors, and age in the development of aggression. In chapter II, I investigate the developmental origins of aggression by examining sensitive periods during which perturbations to the dopaminergic system impact adult aggressive behavior. Previous work in our laboratory has concluded that periadolescent (postnatal days 22-41) elevation in dopamine, via transient dopamine transporter blockade, leads to increased adult aggression and heightened response to amphetamine. I expanded on these findings by temporally refining the opening and closing of this window of sensitivity, specifically to postnatal days 32 to 41, during which increases in dopaminergic tone increase adult aggression and behavioral sensitivity to psychostimulants. The potentiated response to amphetamine indicated to us a state of altered dopaminergic physiology. We next validated this hypothesis and found increased firing rate (in vitro), and increased bursting and population activity (in vivo) at baseline. These data indicate that elevated periadolescent dopamine impacts maturation of the dopamine system, leading to a hyper-active dopaminergic and aggressive predisposition. In conclusion, this chapter introduces a developmental component to the hyper-dopaminergic model of aggression. In chapter III, I report a series of experiments exploring the direct and causal involvement of dopamine in driving aggression. While dopamine hyper-activity is a neural correlate of aggression, the precise brain circuits involved have not been elucidated. Using optogenetics, I established a causal role for the ventral tegmental area (a key source of dopamine) in aggression modulation. I further advanced this finding by demonstrating that the modulatory role of dopamine, is population- and projection-specific. I found that activity of ventral tegmental area, but not substantia nigra, dopamine neurons promotes aggression. Furthermore, controlled stimulation of ventral tegmental area dopaminergic terminals in the lateral septum, but not the nucleus accumbens, mediates increased aggression. I selectively traced connectivity between the lateral septum and the ventral tegmental area using a Cre-driven, population-specific viral vector. I used this virus to show that anatomically distinct clusters of ventral tegmental area dopamine cells send projections to the lateral septum and the nucleus accumbens, thereby dissociating the two target sites both behaviorally and anatomically. Furthermore, I found that while local dopamine release in the lateral septum increases aggression, it has no bearing on reward behaviors thus indicating a stronger association with impulsive, and not motivated, aggression. In conclusion, this chapter offers causal evidence for dopamine’s role in modulating impulsive aggression by identifying a distinct pathway from the ventral tegmental area to the lateral septum that controls aggression. In the work described in chapter IV, my aim was to determine the mechanism underlying ventral tegmental area to lateral septum dopamine-mediated aggression. I first characterized the expression of dopamine receptors in the lateral septum and found that D2 receptors heavily colocalize with the dominant population of neurons in the lateral septum, i.e. GABAergic cells. Moreover, the D2 receptors are perfectly aligned with incoming dopamine afferents. Next we investigated, in acute brain slices, how D2 signaling affects lateral septum function. We revealed that activating D2 receptors hyperpolarizes D2-expressing lateral septum neurons. This effect was abolished with bath application of the D2 receptor antagonist, sulpiride. We validated the functional involvement of post-synaptic D2 signaling in a behavioral test, and found that the aggression induced by direct terminal release of dopamine at the lateral septum is reversed by acutely blocking local D2 receptor signaling. In conclusion, this chapter demonstrates that the ventral tegmental area to lateral septum dopamine pathway, via D2-mediated inhibition of GABAergic lateral septum neurons, is necessary to drive ventral tegmental area-triggered aggression. In chapter V, I engage in a general discussion addressing how the findings from each chapter can be linked to provide a more comprehensive outlook on environmental and genetic risk factors that can modulate ventral tegmental area-triggered aggression. I discuss possible pre- and post-synaptic mechanisms that could impact the functionality of the identified dopaminergic ventral tegmental area to lateral septum pathway. Moreover, in distinguishing this specific dopamine circuit and lateral septum D2 signaling as an underlying correlate of violent pathology, this dissertation aims to evoke deeper understanding of the mechanism of current antipsychotics used to manage aggression. I end this dissertation by proposing new empirical questions, techniques and lines of research that could further develop my findings as well strengthen the links between dominant models of aggression that exist in the field today.

Antipsychotic drugs (typical and atypical) are used in the treatment of mental disorders such as schizophrenia. Typical antipsychotic drugs (such as haloperidol) specifically target dopamine D2 receptors and produce extrapyramidal side effects. Atypical antipsychotic drugs (such as risperidone and olanzapine) primarily target dopamine D2 and serotonin 5HT2A receptors and produce fewer extrapyramidal symptoms (EPS) than do the typical antipsychotic drugs at clinically effective doses (Meltzer and Nash, 1991). It has been proposed that the prefrontal cortex (a brain region implicated in the pathophysiology of schizophrenia) is the locus of antipsychotic drug action to improve cognitive dysfunction and negative symptoms of schizophrenia (Weinberger and Lipska, 1995; Jakab and Goldman-Rakic, 1998). Moreover, it is possible that the effects in the prefrontal cortex may contribute to the differences between typical and atypical antipsychotic drugs as well as differences among atypical antipsychotic drugs (Horacek et al., 2006). The core pathology associated with the dorsolateral prefrontal cortex includes reduced cerebral volume, increased ventricle size and deficits in neuronal morphology, including increased cell packing density, reduction in dendrites and its associated dendritic spines (Selemon and Goldman-Rakic, 1999). However, since most neuropathology data emerge from in vivo imaging and post-mortem studies of patients with schizophrenia, it is difficult to interpret and distinguish between findings that have an etiological or iatrogenic basis. Thus, the objective of the current study was to examine the effects of antipsychotic drugs, at therapeutically relevant concentrations, in a rat brain region that is homologous to that of the human dorsolateral prefrontal cortex. The hypothesis upon which this study was based is that haloperidol, risperidone and olanzapine (at 65 to 80% striatal dopamine D2 receptor occupancy) induce changes to pyramidal cell architecture in the rat anterior cingulate cortex (Vogt and Gabriel, 1993; Hoover and Vertes, 2007). This hypothesis was investigated by (a) determining doses that are within the therapeutic range (65 to 80% striatal dopamine D2 receptor occupancy) by measuring the occupancy of haloperidol, risperidone and olanzapine in the presence of 3H-raclopride ( a dopamine D2 receptor antagonist) at dopamine D2 receptors in the rat striatum; and (b) examining whether therapeutic doses of antipsychotic drugs in rats cause neuropathology comparable to that observed in human post-mortem brains of patients with schizophrenia. Antipsyhcotic drug doses were selected using an appropriate in vivo dopamine D2 receptor occupancy method. The findings from this study revealed that 0.25 mg/kg/day haloperidol, 5 mg/kg/day risperidone and 10 mg/kg/day olanzapine achieved therapeutically relevant rat striatal dopamine D2 receptor occupancy in the range of 65 to 80%. To determine whether antipsychotic drugs at therapeutic doses established above induce changes in neuronal cell density and morphology; immunohistochemistry, single cell injection of lucifer yellow dye and Golgi-Cox impregnation of layer II/III pyramidal cells was performed. The results from these experiments revealed that the density of cells expressing NeuN, parvalbumin, calretinin or calbindin is highly unlikely to be affected by chronic exposure to haloperidol, risperidone and olanzapine. The current study evaluated the effects of chronic antipsychotic drug exposure on spontaneous locomotor activity of a rat in a novel environment. The purpose of this study was to differentiate between a direct and an indirect drug effect. It was found that at the doses established above, risperidone and olanzapine did not overtly reduce spontaneous locomotor activity of a rat in a novel environment relative to controls. In contrast, haloperidol reduced spontaneous locomotor activity of rat in an open field, although this was not statistically significant. Nevertheless, the data reported here allowed us to conclude that the level of activity across groups is unlikely to affect the data obtained in subsequent studies investigating the effects of chronic antipsychotic drug treatment on pyramidal cell structure. Intracellular injection of lucifer yellow dye into pyramidal cells revealed that chronic haloperidol treatment (28 days) was associated with a relative increase in basal dendritic arborisation, but neither of these drug treatments induced changes in arborisation that were different from controls. No statistically significant change in the basal dendritic arbor was detected with animals treated with risperidone relative to controls. Similarly using the Golgi-impregnation method, changes in soma size, dendritic branching, total number of branches and the density of dendritic spines in antipsychotic drug treated groups were not significantly different to controls. Taken together, this finding indicates that only relatively subtle neuritic changes may be attributed to chronic treatment with typical or atypical antipsychotic drugs administered at doses that avhieved striatal dopamine D2 receptor occupancy in the range of 65 to 80%. In summary, this study confirms that antipsychotic drugs are unlikely to induce changes to neuronal cell density or morphology in the rat anterior cingulate cortex at therapeutically relevant doses. Hence, it can be concluded that the observed neuropathology, found in the brains of patients with schizophrenia that have undergone antipsychotic drug therapy, is more likely to be caused by the disease and not the effects of the concomitant drug therapy.

Thesis (DMed)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.

Dissertation (PhD)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: Although schizophrenia is traditionally viewed as an illness with a very poor prognosis, research over the last few years indicates that early intervention may substantially improve the long-term outcome of this disorder. Several studies suggest that patients with first-episode psychosis (FEP) are more sensitive to, and require lower doses of antipsychotic medications than patients with more chronic forms of illness. However, the optimal dose of first-generation anti psychotics in patients with FEP has not been explored extensively and continues to be a controversial subject. This study evaluated the efficacy and safety of low-dose haloperidol in a South African cohort with FEP. The study was conducted in two phases: Phase 1 was an open-label, naturalistic study of 57 subjects with FEP who were commenced on 1mg of haloperidol for 4 weeks, after which gradual escalation of doses were allowed, if required. Subjects who failed to respond at haloperidol 10mg per day were switched to thioridazine. Failure to respond to thioridazine 600mg per day was interpreted to indicate treatment resistance. These subjects were then commenced on clozapine. The principal finding of this phase of the study was that the majority of subjects could be stabilized and maintained on very low doses of haloperidol (1.7 ± 1.0 mg/day at 12 months and 1.3 ±0.8 mg/day at 24 months). Ratings for extra-pyramidal side-effects did not increase significantly from baseline over the duration of the study, except in the case of tardive dyskinesia (TD), where a substantial number of subjects (12.3%) developed TD within 12 months of starting treatment. Phase 2 of the study was a double-blind, randomized controlled trial of low-dose (2mg/day) versus "standard dose" (8mg Iday) haloperidol. Forty subjects were included in this phase of the study; 20 in each treatment arm. The main finding was that there were no significant differences in treatment reponse between the two treatment groups. There were, however, significant differences between the two treatment groups in extrapyramidal side effects (EPSE), with the 8mg per day group exhibiting significantly higher levels of EPSE than the 2mg per day group. This was manifested by significant differences in scores on the Extrapyramidal Symptom Rating Scale (ESRS) and the Simpson-Angus Rating Scale. Furthermore, subjects in the 8mg haloperidol per day group required significantly higher doses of anticholinergic medication and had significantly higher mean levels of prolactin at the end of the study period. This study indicates that a majority of subjects with first-episode psychosis can be treated and maintained successfully with very low doses of haloperidol. It also shows that low-dose treatment is as effective as, and better tolerated than, "standard" doses. Despite the success with the low-dose treatment, however, there was still a much higher than expected incidence of tardive dyskinesia, a serious and potentially irreversible side-effect of neuroleptic treatment. / AFRIKAANSE OPSOMMING: Hoewel skisofrenie tradisioneel gesien is as 'n siekte met 'n uiters swak prognose, dui navorsing oor die afgelope jare daarop dat vroeë ingryping die langtermynuitkoms van hierdie toestand drasties mag verbeter. Resultate van verskeie studies dui daarop dat pasiënte met eerste-episode psigose (EEP) nie net meer sensitief is vir antipsigotiese middels nie, maar ook laer dosisse daarvan benodig tydens behandeling as pasiënte met meer kroniese vorms van psigotiese siekte. Desondanks is die kwessie van die korrekte dosis van eerste generasie antipsigotika in hierdie groep nog onvolledig nagevors en bly dit 'n omstrede onderwerp. Hierdie studie het ten doel gehad om die effektiwiteit en veiligheid van lae dosis haloperidol in 'n Suid-Afrikaanse populasie van pasiënte met EEP te evalueer. Die studie is uitgevoer in twee fases: Fase 1 was 'n oop, naturalistiese studie van 57 pasiënte met EEP wat aanvanklik behandel is met 1mg haloperidol per dag vir 4 weke, waarna geleidelike verhoging van dosisse toegelaat is, soos nodig. Diegene wat nie bevredigende respons getoon het op haloperidol 10mg per dag nie, is oorgeskakel na tioridasien. Ontoereikende respons teen 600mg/dag tioridasien is geïnterpreteer as 'n aanduiding van behandelingsweerstandigheid en behandeling met klosapien is begin. Die belangrikste bevinding van hierdie fase van die studie was dat die meerderheid pasiënte gestabiliseer en in stand gehou kom word op baie lae dosisse haloperidol (1.7 ± 1.0 mg/dag op 12 maande en 1.3 ±0.8 mg/dag op 24 maande). Metings van ekstra-piramidale newe-effekte (EPNE) het nie beduidend toegeneem oor die duur van die studie nie, behalwe in die geval van tardiewe diskinese (TO), waar 'n beduidende aantal pasiënte (12.3%) TO ontwikkel het binne 12 maande na aanvang van behandeling. Fase 2 van die studie was 'n dubbelblinde, ewekansig gerandomiseerde studie waarin behandeling met lae dosis haloperidol (2mg/dag) vergelyk is met "standaard" dosis haloperidol (8mg/dag). Veertig pasiënte is ingesluit in hierdie fase van die studie, 20 in elke behandelingsarm. Die hoofbevinding was dat daar geen beduidende verskille in respons op behandeling was tussen die twee groepe nie. Daar was egter beduidende verskille in EPNE, waar die 8mg/dag groep beduidend hoër vlakke van EPNE gehad het as die 2mg/dag groep. Hierdie verskil in EPNE is aangedui deur 'n statisties beduidende verskil in tellings op die Extrapyramidal Symptom Rating Scale (ESRS) en die Simpson- Angus Rating Scale. Verder het pasiënte in die 8mg/dag groep beduidend hoër dosisse antikolinerge medikasie benodig en ook hoër gemiddelde prolaktienvlakke gehad teen die einde van studie. Hierdie studie dui dus daarop dat die meerderheid van pasiënte met EEP suksesvol behandel en in stand gehou kan word met baie lae dosisse haloperidol. Die studie wys ook daarop dat behandeling met lae dosisse net so effektief is en beter verdra word as behandeling met "standaard" dosisse. Ten spyte van die suksesvolle gebruik van lae dosisse medikasie het die studie egter ook getoon dat daar "n baie hoër as verwagte insidensie was van TO, "n emstige en potensieelonomkeerbare newe-effek van neuroleptiese behandeling.

Schizophrenia is a debilitating psychiatric condition affecting almost one percent of the US population. Typical antipsychotics (e.g., haloperidol) have been in use for several decades and are generally very effective in treating the emotional and cognitive effects of schizophrenia, but are used as the last line of treatment due to their severe extrapyramidal motor side effects under chronic exposure. The present study was conducted to investigate the role of sex in determining the oromotor side effects of typical antipsychotics via measuring different behavioral dimensions of male and female Sprague-Dawley rats licking sucrose after haloperidol treatment. The results showed a stronger sensitivity in female rats than male rats within total licking responses and inter-lick intervals. The present results suggest closer attention needs to be paid to the role that sexual hormones play in the motor slowing and behavior-reducing effects of antipsychotics.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2018-04-04T11:49:33Z No. of bitstreams: 2 Dissertação - Nícolas Gustavo Matias de Oliveira - 2018.pdf: 1671663 bytes, checksum: 77209b17924ba8b6327e4442c9878a74 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-04-04T13:24:34Z (GMT) No. of bitstreams: 2 Dissertação - Nícolas Gustavo Matias de Oliveira - 2018.pdf: 1671663 bytes, checksum: 77209b17924ba8b6327e4442c9878a74 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-04-04T13:24:34Z (GMT). No. of bitstreams: 2 Dissertação - Nícolas Gustavo Matias de Oliveira - 2018.pdf: 1671663 bytes, checksum: 77209b17924ba8b6327e4442c9878a74 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-03-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Schizophrenia (EQZ) is a chronic mental illness that affects about 1% of the world population and is characterized by behavioral domains such as positive symptoms characterized by hallucinations and delusions and negative symptoms that involve apathy, anhedonia and social blunting. The cause of EQZ remains unknown, but it is known to be a disease whose etiology involves environmental and genetic factors. Several studies seek to identify factors that clarify the etiology of the disease. The agent that causes toxoplasmosis, Toxoplasma gondii, seems to be related to the development and progression of the disease, evidenced by studies that argue that T. gondii infection may be a triggering factor for psychosis in some individuals, since the parasite has a certain tropism by the central nervous system. Furthermore, studies have reported parasite infection as a factor related to genotoxicity, including toxoplasma infection in an animal model. Based on the foregoing, the present study aimed to evaluate the seropositivity to T. gondii (IgM or IgG) and the avidity of IgG in a group of individuals diagnosed with EQZ in the city of Goiânia and to evaluate the occurrence of genotoxicity in these, of genotoxicity with exposure to xenobiotics such as tobacco, alcohol, especially drugs, and / or T. gondii infection. Seropositivity was observed above 70% among individuals diagnosed with EQZ in relation to the controls, with avidity above 50%, indicating that individuals had contact with T. gondii at some time prior to the survey. Despite the genotoxic damage found, there was no significant difference in genotoxic damage among the infected individuals evaluated. The present study did not demonstrate that T. gondii may be a contributing factor to the occurrence of DNA damage, and the use of antipsychotic drugs, tobacco and alcohol, despite being a risk factor for genotoxicity, did not demonstrate an influence significant difference in the present study. However, it is necessary to carry out other analyzes and investigate parameters such as the time of drug use and exposure to other xenobiotics. In order to know better the life habits of individuals, it may help to provide more information about this relationship between T. gondii and EQZ. / A esquizofrenia (EQZ) é uma doença mental crônica que afeta cerca de 1% da população mundial e se caracteriza por domínios comportamentais, como sintomas positivos, caracterizados por alucinações e delírios e sintomas negativos, que envolvem apatia, anedonia e embotamento social. A causa da EQZ ainda permanece desconhecida, mas sabe-se que se trata de uma doença que cuja etiologia envolve fatores ambientais e genéticos. Vários estudos buscam identificar fatores que esclareçam a etiologia da doença. O agente causador da toxoplasmose, Toxoplasma gondii, parece ter relação com o desenvolvimento e progressão da doença, evidenciado por estudos que defendem que a infecção por T. gondii pode ser um fator desencadeante de psicoses em alguns indivíduos, já que o parasito apresenta um certo tropismo pelo sistema nervoso central. Ainda, estudos tem reportado a infecção por parasitos como fator relacionado a genotoxicidade, incluindo a infecção pelo toxoplasma em um modelo animal. Com base no exposto, o presente trabalho teve por objetivo avaliar a soropositividade para T. gondii (IgM ou IgG) e a avidez da IgG em um grupo de indivíduos diagnosticados com EQZ do município de Goiânia e avaliar a ocorrência de genotoxicidade nestes, procurando relação da genotoxicidade com a exposição a xenobióticos como tabaco, álcool, especialmente medicamentos, e/ou com a infecção pelo T. gondii. Observou- se soropositividade acima de 70% entre os indivíduos diagnosticados com EQZ em relação aos controles, com avidez acima de 50%, indicando que os indivíduos tiveram contato com o T. gondii em algum momento anterior a pesquisa. Apesar do dano genotóxico encontrado, não houve diferença significativa no dano genotóxico entre os indivíduos infectados avaliados. O presente estudo não demonstrou que T. gondii pode ser um fator contribuinte para a ocorrência de danos ao DNA, e o uso de fármacos antipsicóticos, o fumo e o álcool, apesar de serem um fator de risco para a genotoxicidade, não demonstraram uma influência significativa no presente estudo. Entretanto, há a necessidade de realizar outras análises e investigar parâmetros como o tempo de uso dos fármacos, e de exposição a outros xenobióticos, enfim, o melhor conhecimento dos hábitos de vida dos indivíduos pode ajudar a trazer mais informações acerca dessa relação entre T. gondii e a EQZ.