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Decades of research in social identity have shown that people instinctively hold positive attitudes towards ingroup members and negative attitudes towards outgroup members. However, it remains unclear how people respond to individuals explicitly identified with both one's ingroup and outgroup. We propose that when people are exposed to dual-identified individuals and groups (e.g., Muslim-Americans explicitly identifying with both their Muslim and American identities), intergroup attitudes will improve, driven more by the ingroup component (American), despite the presence of the outgroup component (Muslim). Moreover, we suggest exposure to dual-identification can also improve attitudes toward the broader outgroup (Muslims more generally), a phenomenon called the gateway-group effect. To test these hypotheses, we created a new measure of dual-identification and conducted three studies involving both Muslim-Americans and Mexican-Americans. Results confirmed that exposure to explicitly dual-identified groups improved attitudes towards the dual-identified group (e.g., Mexican-Americans) as well as toward the respective outgroup (e.g., Mexicans).
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Ódio , Amor , Humanos , Preconceito , Atitude , Identificação Social , Processos GrupaisRESUMO
Repulsive guidance molecule A (RGMa) is an inhibitor of neuronal growth and survival which is upregulated in the damaged central nervous system following acute spinal cord injury (SCI), traumatic brain injury, acute ischemic stroke (AIS), and other neuropathological conditions. Neutralization of RGMa is neuroprotective and promotes neuroplasticity in several preclinical models of neurodegeneration and injury including multiple sclerosis, AIS, and SCI. Given the limitations of current treatments for AIS due to narrow time windows to intervention (TTI), and restrictive patient selection criteria, there is significant unmet need for therapeutic agents that enable tissue survival and repair following acute ischemic damage for a broader population of stroke patients. In this preclinical study, we evaluated whether elezanumab, a human anti-RGMa monoclonal antibody, could improve neuromotor function and modulate neuroinflammatory cell activation following AIS with delayed intervention times up to 24 h using a rabbit embolic permanent middle cerebral artery occlusion model (pMCAO). In two replicate 28-day pMCAO studies, weekly intravenous infusions of elezanumab, over a range of doses and TTIs of 6 and 24 h after stroke, significantly improved neuromotor function in both pMCAO studies when first administered 6 h after stroke. All elezanumab treatment groups, including the 24 h TTI group, had significantly less neuroinflammation as assessed by microglial and astrocyte activation. The novel mechanism of action and potential for expanding TTI in human AIS make elezanumab distinct from current acute reperfusion therapies, and support evaluation in clinical trials of acute CNS damage to determine optimal dose and TTI in humans. A: Ramified/resting astrocytes and microglia in a normal, uninjured rabbit brain. B: Rabbit pMCAO brain illustrating lesion on right side of brain (red), surrounded by penumbra (pink) during acute phase post stroke, with minimal injury to left brain hemisphere. Penumbra characterized by activated astrocytes and microglia (region in crosshair within circle), with upregulation of free and bound RGMa. C: Elezanumab binds to both free and bound RGMa, preventing full activation of astrocytes and microglia. D: Elezanumab is efficacious in rabbit pMCAO with a 4 × larger TTI window vs. tPA (6 vs. 1.5 h, respectively). In human AIS, tPA is approved for a TTI of 3-4.5 h. Elezanumab is currently being evaluated in a clinical Ph2 study of AIS to determine the optimal dose and TTI (NCT04309474).
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The past generation has seen a dramatic rise in multiracial populations and a consequent increase in exposure to individuals who challenge monolithic racial categories. We examine and compare two potential outcomes of the multiracial population growth that may impact people's racial categorization experience: (a) exposure to racially ambiguous faces that visually challenge the existing categories, and (b) a category that conceptually challenges existing categories (including "biracial" as an option in addition to the monolithic "Black" and "White" categories). Across four studies (N = 1,810), we found that multiple exposures to faces that are racially ambiguous directly lower essentialist views of race. Moreover, we found that when people consider a category that blurs the line between racial categories (i.e., "biracial"), they become less certain in their racial categorization, which is associated with less race essentialism, as well. Importantly, we found that these two effects happen independently from one another and represent two distinct cognitive processes.
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Reconhecimento Facial , Grupos Raciais , População Branca , Humanos , População Negra , Grupos Raciais/classificação , Grupos Raciais/psicologia , IncertezaRESUMO
Can people accurately perceive who is authentic? Laypeople believe they can tell who is authentic, and they report that authenticity is an important attribute in others (Studies 1a and 1b; N = 369). However, when we directly tested the accuracy of perceived authenticity, we found no significant correlation between self- and other-rated authenticity in two cohorts of adult students in randomly assigned teams (Studies 2 and 3; 4,040 self-other observations). In addition, we found that perceived authenticity was biased in two ways: (a) Other-rated authenticity showed a positivity bias compared with self-ratings, and (b) other-rated authenticity was biased by the rater's own authenticity. In Study 3, we also investigated authenticity meta-perceptions; although people expect their authenticity to be accurately perceived by others, their meta-perceptions did not correlate with other-rated authenticity. That is, beliefs about the visibility of one's authenticity are similarly not accurate. Overall, we found no evidence that people can accurately identify who is authentic.
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Percepção , Adulto , Viés , HumanosRESUMO
Visual impairments, notably loss of contrast sensitivity and color vision, were documented in Alzheimer's disease (AD) patients yet are critically understudied. This protocol describes a novel visual-stimuli four-arm maze (ViS4M; also called visual x-maze), which is a versatile x-shaped maze equipped with spectrum- and intensity-controlled light-emitting diode (LED) sources and dynamic grayscale objects. The ViS4M is designed to allow the assessment of color and contrast vision along with locomotor and cognitive functions in mice. In the color testing mode, the spectral distributions of the LED lights create four homogenous spaces that differ in chromaticity and luminance, corresponding to the mouse visual system. In the contrast sensitivity test, the four grayscale objects are placed in the middle of each arm, contrasting against the black walls and the white floors of the maze. Upon entering the maze, healthy wild-type (WT) mice tend to spontaneously alternate between arms, even under equiluminant conditions of illumination, suggesting that cognitively and visually intact mice use both color and brightness as cues to navigate the maze. Evaluation of the double-transgenic APPSWE/PS1ΔE9 mouse model of AD (AD+ mice) reveals substantial deficits to alternate in both color and contrast modes at an early age, when hippocampal-based memory and learning is still intact. Profiling of timespan, entries, and transition patterns between the different arms uncovers variable aging and AD-associated impairments in color discrimination and contrast sensitivity. The analysis of arm sequences of alternation reveals different pathways of exploration in young WT, old WT, and AD+ mice, which can be used as color and contrast imprints of functionally intact versus impaired mice. Overall, we describe the utility of a novel visual x-maze test to identify behavioral changes in mice related to cognition, as well as color and contrast vision, with high precision and reproducibility. Graphic abstract: Exploratory behavior of AD+ mice versus age- and sex-matched WT mice is tracked (top left: trajectory from a 5-min video file) in a novel visual-stimuli four-arm maze (ViS4M; also named visual x-maze) equipped with spectrum- and intensity-controlled LED sources or grayscale objects. Consecutive arm entries reveal that APPSWE/PS1ΔE9 (AD+) mice alternate less between arms, as opposed to WT mice. Sequence analysis, according to the three alternation pathways (depicted by white, yellow, and brown arrows) under different conditions of illumination, uncovers specific deficits linked to color vision in AD+ mice, evidenced by a color imprint chart.
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Why did COVID-19 hit some countries harder than others? While this question is usually answered based on demographics (e. g., population age), health policy (e.g., quarantine), or economic factors, we argue that cultural variance across countries is just as crucial in understanding how susceptible a society is to the COVID-19 outbreak. To test this hypothesis, we first analyzed data collected across 69 countries and examined the relationship between culture and the impact of COVID. Next, we conducted two studies to validate our findings further and explore the mechanism at hand. As expected, we found that the more individualistic (vs. collectivistic) a country was, the more COVID-19 cases and mortalities it had. We also found that the more individualistic participants were, the higher the chances they would not adhere to epidemic prevention measures. These findings are important in understanding the spread of the pandemic, devising optimal exit strategies from lockdowns, and persuading the population to get the new vaccine against the virus.
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COVID-19 , Cultura , Fidelidade a Diretrizes , Individualidade , Pandemias , Adulto , COVID-19/transmissão , Comparação Transcultural , Feminino , Humanos , Israel , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , SARS-CoV-2RESUMO
We introduce a novel visual-stimuli four-arm maze (ViS4M) equipped with spectrally- and intensity-controlled LED emitters and dynamic grayscale objects that relies on innate exploratory behavior to assess color and contrast vision in mice. Its application to detect visual impairments during normal aging and over the course of Alzheimer's disease (AD) is evaluated in wild-type (WT) and transgenic APPSWE/PS1∆E9 murine models of AD (AD+) across an array of irradiance, chromaticity, and contrast conditions. Substantial color and contrast-mode alternation deficits appear in AD+ mice at an age when hippocampal-based memory and learning is still intact. Profiling of timespan, entries and transition patterns between the different arms uncovers variable AD-associated impairments in contrast sensitivity and color discrimination, reminiscent of tritanomalous defects documented in AD patients. Transition deficits are found in aged WT mice in the absence of alternation decline. Overall, ViS4M is a versatile, controlled device to measure color and contrast-related vision in aged and diseased mice.
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Doença de Alzheimer/fisiopatologia , Percepção de Cores , Sensibilidades de Contraste , Hipocampo/fisiopatologia , Aprendizagem em Labirinto , Memória , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Animais , Modelos Animais de Doenças , Camundongos , Camundongos TransgênicosRESUMO
There is unmet need for effective stroke therapies. Numerous neuroprotection attempts for acute cerebral ischemia have failed and as a result there is growing interest in developing therapies to promote functional recovery through increasing synaptic plasticity. For this research study, we hypothesized that in addition to its previously reported role in mediating cell death during the acute phase, the alpha isoform of p38 mitogen-activated protein kinase, p38α, may also contribute to interleukin-1ß-mediated impairment of functional recovery during the subacute phase after acute ischemic stroke. Accordingly, an oral, brain-penetrant, small molecule p38α inhibitor, neflamapimod, was evaluated as a subacute phase stroke treatment to promote functional recovery. Neflamapimod administration to rats after transient middle cerebral artery occlusion at two dose levels was initiated outside of the previously characterized therapeutic window for neuroprotection of less than 24 hours for p38α inhibitors. Six-week administration of neflamapimod, starting at 48 hours after reperfusion, significantly improved behavioral outcomes assessed by the modified neurological severity score at Week 4 and at Week 6 post stroke in a dose-dependent manner. Neflamapimod demonstrated beneficial effects on additional measures of sensory and motor function. It also resulted in a dose-related increase in brain-derived neurotrophic factor (BDNF) protein levels, a previously reported potential marker of synaptic plasticity that was measured in brain homogenates at sacrifice. Taken together with literature evidence on the role of p38α-dependent suppression by interleukin-1ß of BDNF-mediated synaptic plasticity and BDNF production, our findings support a mechanistic model in which inhibition of p38α promotes functional recovery after ischemic stroke by blocking the deleterious effects of interleukin-1ß on synaptic plasticity. The dose-related in vivo efficacy of neflamapimod offers the possibility of having a therapy for stroke that could be initiated outside the short time window for neuroprotection and for improving recovery after a completed stroke.
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Isquemia Encefálica/tratamento farmacológico , Piridazinas/farmacologia , Pirimidinas/farmacologia , Acidente Vascular Cerebral/tratamento farmacológico , Animais , Encéfalo/metabolismo , Isquemia Encefálica/complicações , Isquemia Encefálica/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Infarto da Artéria Cerebral Média/complicações , Isquemia/complicações , Masculino , Proteína Quinase 14 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 14 Ativada por Mitógeno/metabolismo , Piridazinas/metabolismo , Pirimidinas/metabolismo , Ratos , Ratos Sprague-Dawley , Recuperação de Função Fisiológica/efeitos dos fármacos , Recuperação de Função Fisiológica/fisiologia , Acidente Vascular Cerebral/complicações , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Peptidase-resistant, lanthionine-stabilized angiotensin-(1-7), termed cAng-(1-7), has shown therapeutic efficacy in animal models of cardiovascular, metabolic, kidney and pulmonary disease. Goal of the present study was testing the capacity of subcutaneously administered cAng-(1-7) to induce rehabilitation of animal performance in the transient middle cerebral artery occlusion rat model of cerebral stroke. 24â¯h after ischemic stroke induction, cAng-(1-7) was administered for 28 days at a dose of 500⯵g/kg/day, either daily via subcutaneous injection or continuously via an alzet pump. Both ways of administration of cAng-(1-7) were equally effective. Measurements were continued until day 50. Compared to vehicle, cAng-(1-7) clearly demonstrated significantly increased capillary density (pâ¯<â¯0.01) in the affected hemisphere and improved motor and somatosensory functioning. The modified neurological severity score (pâ¯<â¯0.001 at days 15 and 50), stepping test (pâ¯<â¯0.001 at days 36-50), forelimb placement test (pâ¯<â¯0.001 at day 50), body swing test (pâ¯<â¯0.001 at days 43 and 50) all demonstrated that cAng-(1-7) caused significantly improved animal performance. Taken together the data convincingly indicate rehabilitating capacity of subcutaneously injected cAng-(1-7) in cerebral ischemic stroke.
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Angiotensina I/farmacologia , Fragmentos de Peptídeos/farmacologia , Peptídeos Cíclicos/farmacologia , Recuperação de Função Fisiológica/efeitos dos fármacos , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Animais , Modelos Animais de Doenças , Masculino , Ratos , Ratos Sprague-Dawley , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/fisiopatologiaRESUMO
The modern era of globalization has been accompanied by a massive growth in interconnections between groups, and has led to the sharing of multiple identities by individuals and groups. Following these developments, research has focused on the issue of multiple identities, and has shed important light on how individuals who hold these complex forms of identity feel and behave, and on the reactions they elicit from members of other groups. However, the potential of groups with such multiple identities (e.g., biracials, immigrants, etc.) to affect the intergroup relations between the groups that represent the respective sources of the different identities (e.g., Blacks and Whites, country of origin and country of residence, etc.) has not been examined to date. Accordingly, in this paper, we first systematically explore the potential of groups in which people identify with multiple social categories, or groups that are perceived as such by others, to play a role in intergroup dynamics. Next, we offer a theoretical framework outlining what functions groups of people with shared multiple identities may serve (as bridges or barriers) by proposing how their presence may facilitate or deteriorate intergroup relations. Finally, we present recent empirical research examining how groups of people with shared multiple identities can act as gateways and bridge the cleft between two separate groups that represent the respective sources of their different identities, and discuss the theoretical and practical implications for the field of intergroup relations.
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Long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) exert health benefits which are dependent upon their incorporation into blood, cells and tissues. Plasma and tissue deposition of LC n-3 PUFA from oils extracted from the micro-algae Nannochloropsis oculata and from krill were compared in rats. The algal oil provides eicosapentaenoic acid (EPA) partly conjugated (15%) to phospholipids and glycolipids but no docosahexaenoic acid (DHA), whereas krill oil provides both EPA and DHA conjugated in part (40%) to phospholipids. Rats fed a standard diet received either krill oil or polar-lipid rich algal oil by gavage daily for 7 days (5 ml oil per kg body weight each day). Fatty acid concentrations were analyzed in plasma, brain and liver, and two adipose depots since these represent transport, functional and storage pools of fatty acids, respectively. When measuring total LC n-3 PUFA (sum of EPA, docosapentaenoic acid (DPA) and DHA), there was no statistically significant difference between the algal oil and krill oil for plasma, brain, liver and gonadal adipose tissue. Concentrations of LC n-3 PUFA were higher in the retroperitoneal adipose tissue from the algal oil group. Tissue uptake of LC n-3 PUFA from an algal oil containing 15% polar lipids (glycolipids and phospholipids) was found to be equivalent to krill oil containing 40% phospholipids. This may be due to glycolipids forming smaller micelles during ingestive hydrolysis than phospholipids. Ingestion of fatty acids with glycolipids may improve bioavailability, but this needs to be further explored.
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Suplementos Nutricionais , Euphausiacea/química , Ácidos Graxos Ômega-3/metabolismo , Microalgas/química , Óleos/metabolismo , Estramenópilas/química , Tecido Adiposo Branco/metabolismo , Animais , Encéfalo/metabolismo , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácidos Docosa-Hexaenoicos/sangue , Ácidos Docosa-Hexaenoicos/metabolismo , Ácido Eicosapentaenoico/administração & dosagem , Ácido Eicosapentaenoico/sangue , Ácido Eicosapentaenoico/metabolismo , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-3/sangue , Feminino , Glicolipídeos/administração & dosagem , Glicolipídeos/metabolismo , Fígado/metabolismo , Masculino , Especificidade de Órgãos , Fosfolipídeos/administração & dosagem , Fosfolipídeos/metabolismo , Ratos Sprague-DawleyRESUMO
PURPOSE OF THE STUDY: The novel combination of 0.1% sodium hyaluronate (HA) and 5.0% polyvinylpyrrolidone (PVP) into one eyedrop was investigated to test the hypothesis of its increased relief of dry eye syndrome (DES). MATERIALS AND METHODS: We evaluated HA and PVP, either alone, or in combination, by utilizing 16 rabbits, where their right eyes received one or two different eyedrops, and their left eyes, as controls, received none. The DES replica in rabbits was induced by 0.1% benzalkonium chloride (BAC) eyedrops. BAC was instilled into the right eyes of all rabbits, which were divided into four groups of four. In Group 1 M, the rabbits received only BAC. A second eyedrop given to the right eyes of Group 2 M was HA, of Group 3 M was PVP, and of Group 4 M was the combination of both HA and PVP. All eyes were followed clinically for 14 d, and thereafter, examined histopathologically. RESULTS: Clinically, the HA+PVP combination yielded the least perilimbal conjunctival erythema (p < 0.05), and the least corneal epithelial fluorescein staining (p < 0.001) compared to each treatment alone. Histopathologically, all four rabbits' right eyes in the combination group 4 M displayed the greatest preservation of the corneal epithelium (p < 0.001) and of the perilimbal conjunctival goblet cell density (p < 0.001). CONCLUSIONS: This unique combination of both HA and PVP into one eyedrop, was more potent than either treatment alone in protecting the ocular surface. A preparation, containing both HA and PVP may become useful for DES patients.
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Córnea/patologia , Síndromes do Olho Seco/tratamento farmacológico , Ácido Hialurônico/administração & dosagem , Povidona/administração & dosagem , Adjuvantes Imunológicos/administração & dosagem , Animais , Córnea/efeitos dos fármacos , Córnea/metabolismo , Modelos Animais de Doenças , Quimioterapia Combinada , Síndromes do Olho Seco/metabolismo , Síndromes do Olho Seco/patologia , Humanos , Masculino , Soluções Oftálmicas , Substitutos do Plasma/administração & dosagem , Coelhos , Resultado do TratamentoRESUMO
An arson suspect's contact with an ignitable liquid container can leave small traces of the substance on his hands, but detecting these traces is difficult. This research paper presents a method to obtain clear gasoline detection even 3h after hands have been moistened with 50 µL of gasoline using activated charcoal strips to adsorb the ignitable liquid traces directly from the suspect's hands. Light heating of the hands to 45 °C significantly increases the ability to detect gasoline traces. This methodology is part of a system to sample a suspect's hands at the scene of crime or in a police station. Samples are taken by investigators then analyzed in a laboratory. The suggested method provides an important improvement in detection sensitivity for ignitable liquids on suspect's hands.
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Immediate administration of antidotal treatment is crucial in severe organophosphate (OP) poisoning and the use of an open intravenous (i.v.) line might also be required. The state of casualties might prevent getting access to their veins. The bone injection gun (BIG) was established as a simple method for introducing an intraosseous (i.o.) line and could be applied while wearing a protective suit. The present study followed the pharmacokinetics of the anticonvulsive drug midazolam after i.o. administration in pigs compared with i.v. and the common intramuscular (i.m.) administration. A new method for monitoring midazolam concentrations in plasma was developed. Plasma concentrations following both i.v. and i.o. administrations peaked at 2 min post injection and only at 10 min following the i.m. route. In an antidotal treatment study against paraoxone poisoning, the anticonvulsive effect of midazolam appeared immediately following i.o. administration, while it took 5-10 min to exhibit a similar effect following i.m. administration. This study indicates that the use of i.o. administration after OP poisoning might provide the necessary fast response for rapid termination of convulsions. The BIG might offer a convenient method for treating casualties in the chemical arena by teams wearing full protective gear.
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Anticonvulsivantes/uso terapêutico , Antídotos/uso terapêutico , Midazolam/uso terapêutico , Intoxicação por Organofosfatos , Paraoxon/intoxicação , Convulsões/tratamento farmacológico , Animais , Anticonvulsivantes/administração & dosagem , Anticonvulsivantes/farmacocinética , Antídotos/administração & dosagem , Antídotos/farmacocinética , Disponibilidade Biológica , Relação Dose-Resposta a Droga , Infusões Intraósseas/instrumentação , Injeções Intramusculares/instrumentação , Injeções Intravenosas , Midazolam/administração & dosagem , Midazolam/farmacocinética , Intoxicação/tratamento farmacológico , Convulsões/induzido quimicamente , SuínosRESUMO
A novel method for the estimation of intermediate-long firing distance range is proposed. The method is based on the characterization and chemical analysis of the smokeless powder particles on the target. An adhesive lifter is applied to collect the suspected gunshot residues (GSRs) from the surface of an object, and a Modified Griess Test (MGT) is carried out after alkaline hydrolysis on the adhesive lifter. Visualized particles are removed from the adhesive lifter under a microscope. Two systems are used for the analysis of organic discharge residues from the smokeless powder: (1) gas chromatography/thermal energy analysis (GC/TEA) for the analysis of nitroglycerine (NG) and 2,4-dinitrotoluene (2,4-DNT), (2) gas chromatography/mass spectrometry (GC/MS) for the identification of organic components such as DNT, NG, and some stabilizers. By using this procedure and confirming that the suspected particles are indeed GSR, one can estimate the intermediate-long firing distance of c. 0.75-3 m in the presence of very few particles and provide information for the classification of ammunition type in casework.
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The extrapolation from animal data to therapeutic effects in humans, a basic pharmacological issue, is especially critical in studies aimed to estimate the protective efficacy of drugs against nerve agent poisoning. Such efficacy can only be predicted by extrapolation of data from animal studies to humans. In pretreatment therapy against nerve agents, careful dose determination is even more crucial than in antidotal therapy, since excessive doses may lead to adverse effects or performance decrements. The common method of comparing dose per body weight, still used in some studies, may lead to erroneous extrapolation. A different approach is based on the comparison of plasma concentrations at steady state required to obtain a given pharmacodynamic endpoint. In the present study, this approach was applied to predict the prophylactic efficacy of the anticholinergic drug caramiphen in combination with pyridostigmine in man based on animal data. In two species of large animals, dogs and monkeys, similar plasma concentrations of caramiphen (in the range of 60-100 ng/ml) conferred adequate protection against exposure to a lethal-dose of sarin (1.6-1.8 LD(50)). Pharmacokinetic studies at steady state were required to achieve the correlation between caramiphen plasma concentrations and therapeutic effects. Evaluation of total plasma clearance values was instrumental in establishing desirable plasma concentrations and minimizing the number of animals used in the study. Previous data in the literature for plasma levels of caramiphen that do not lead to overt side effects in humans (70-100 ng/ml) enabled extrapolation to expected human protection. The method can be applied to other drugs and other clinical situations, in which human studies are impossible due to ethical considerations. When similar dose response curves are obtained in at least two animal models, the extrapolation to expected therapeutic effects in humans might be considered more reliable.
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Avaliação Pré-Clínica de Medicamentos/métodos , Intoxicação por Organofosfatos , Intoxicação/prevenção & controle , Animais , Substâncias para a Guerra Química/intoxicação , Antagonistas Colinérgicos/administração & dosagem , Antagonistas Colinérgicos/farmacocinética , Antagonistas Colinérgicos/uso terapêutico , Ciclopentanos/sangue , Ciclopentanos/farmacocinética , Ciclopentanos/uso terapêutico , Modelos Animais de Doenças , Cães , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Feminino , Humanos , Infusões Intravenosas , Infusões Parenterais , Dose Letal Mediana , Masculino , Taxa de Depuração Metabólica , Organofosfatos/administração & dosagem , Organofosfatos/sangue , Papio anubis , Intoxicação/sangue , Brometo de Piridostigmina/sangue , Brometo de Piridostigmina/farmacocinética , Brometo de Piridostigmina/uso terapêutico , Sarina/administração & dosagem , Sarina/intoxicação , Especificidade da Espécie , Resultado do TratamentoRESUMO
Organophosphate (OP) poisoning, which inhibits cholinesterase activity, leads to severe cholinergic symptoms. Effective and quick management of these symptoms is considered critical to the clinical outcome. Acute renal damage following exposure to OP insecticides has been reported. Similar complications might occur following exposure to OP nerve agents, however, this subject has been studied only sporadically. In the present study, the effect of the nerve agent sarin on renal function was examined in rats. A single dose of sarin ( approximately 0.9 LD(50)) led to a significant reduction (of 45%) in renal function during the first 2 days post exposure, as exhibited by evaluation of the glomerular filtration rate, through measuring the clearance of ( 99m)Tc-DTPA. The urine volume was reduced by 50%, the urine specific gravity increased to 104% of the control value and massive hematuria and glucosuria were recorded 24-48 h post exposure. In addition, around 60% decrease in urine electrolytes was monitored during the first 2 days following exposure, with a recovery after 8 days. Post mortem gross inspection of the bladder, 24 h post exposure, revealed severe edema and hemorrhage. Treatment with the muscarinic antagonist atropine and the oxime TMB-4, at excessive doses administered 1 min post exposure, did not prevent most renal impairments. It has been concluded that sarin caused an acute renal dysfunction, possibly accompanied by bladder damage. These impairments were reversible, recovered spontaneously within 3-8 days, and were probably related to the state of shock and hypovolemia caused by the poisoning. However, if renal impairments are left unattended, they might contribute to the overall toxic manifestation and as a result aggravate the clinical state of intoxicated casualties.
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Substâncias para a Guerra Química/toxicidade , Inibidores da Colinesterase/toxicidade , Taxa de Filtração Glomerular/efeitos dos fármacos , Nefropatias/induzido quimicamente , Rim/efeitos dos fármacos , Sarina/toxicidade , Animais , Antídotos/farmacologia , Atropina/farmacologia , Reativadores da Colinesterase/farmacologia , Glicosúria/induzido quimicamente , Glicosúria/patologia , Hematúria/induzido quimicamente , Hematúria/patologia , Rim/fisiopatologia , Nefropatias/patologia , Nefropatias/fisiopatologia , Masculino , Ratos , Ratos Sprague-Dawley , Recuperação de Função Fisiológica , Fatores de Tempo , Trimedoxima/farmacologia , Urinálise , Bexiga Urinária/efeitos dos fármacos , Bexiga Urinária/patologiaRESUMO
INTRODUCTION: Scopolamine is highly effective for the treatment of seasickness. Nevertheless, transdermal therapeutic system (TTS) scopolamine, despite high compliance on the part of persons treated by the drug, fails to provide protection against seasickness in 26-38% of patients. To the best of our knowledge, the correlation between scopolamine levels in plasma and its therapeutic effect under sailing conditions in the open sea is investigated for the first time in the present study. METHODS: Subjects were 61 crewmembers of naval vessels treated by TTS scopolamine. The therapeutic response at sea was documented by questionnaire. During a period ashore, a TTS scopolamine patch was applied in the same subjects. Blood samples were taken and an adverse effects questionnaire completed 8 h after scopolamine patch application. Scopolamine levels were determined using an established radio-receptor assay procedure. To verify the reproducibility of these measurements, blood samples were taken twice from most subjects, on separate days after different patch applications. Subjects were divided into "responders," who reported at least a moderate decrease in seasickness severity compared with their previous experience at sea without TTS scopolamine therapy, and "non-responders," who had only slight symptomatic relief or no relief at all. RESULTS: The mean scopolamine concentration in the plasma of the 37 responders (156.77 +/- 77.03 pg x ml(-1)) was significantly higher than the mean level in the 24 non-responders (97.03 +/- 73.34 pg x ml(-1); p = 0.005, simple t-test). CONCLUSIONS: Attempts to increase scopolamine levels in plasma by increasing the drug dosage or improving transdermal absorption should be considered for the treatment of "non-responders".
Assuntos
Militares , Enjoo devido ao Movimento/prevenção & controle , Antagonistas Muscarínicos/farmacocinética , Antagonistas Muscarínicos/uso terapêutico , Escopolamina/farmacocinética , Escopolamina/uso terapêutico , Absorção , Administração Cutânea , Adolescente , Adulto , Humanos , Masculino , Pessoa de Meia-Idade , Antagonistas Muscarínicos/administração & dosagem , Escopolamina/administração & dosagem , Resultado do TratamentoRESUMO
The protein kinase C (PKC) signaling pathway has been associated with modulation of N-metyl-D-aspartate receptor activity, motor behavior, learning, and memory, all of which are severely impaired in organophosphate (OP) intoxication. Nevertheless, the role of PKC in OP intoxication is largely unknown. The present study attempted to characterize alterations in the immunoreactivity levels of PKC isozymes expressed in different brain areas in the rat following exposure to the nerve agent sarin (1x LD(50)). Furthermore, possible neuroprotective effect of selective PKC regulating peptide after such insult was evaluated. The results indicated that a significant reduction in the immunoreactivity level of the conventional betaII-PKC and the atypical zeta-PKC was observed in frontal cortex up to 24 h postsarin and in the striatum up to 5 days postsarin exposure. This reduction was in contrast to the increase in the immuno-reactivity level of both isozymes seen in the hippocampus or thalamus. Treatment with the anticonvulsant midazolam (0.5 mg/kg) 10 min postsarin exposure markedly reduced zeta-PKC immunoreactivity level and betaII-PKC in the membrane fractions in the hippocampus. betaII-PKC peptide (380 ng/kg), known to inhibit PKC translocation and activation, attenuated sarin-induced neuropathology. These observations suggest a role for both conventional and atypical PKC isozymes in OP-induced neuropathy in the rat and further support their involvement in cell death.
Assuntos
Encéfalo/efeitos dos fármacos , Isoenzimas/análise , Proteína Quinase C/análise , Sarina/intoxicação , Animais , Encéfalo/enzimologia , Encéfalo/patologia , Encéfalo/ultraestrutura , Masculino , Proteína Quinase C/fisiologia , Ratos , Ratos Sprague-DawleyRESUMO
The treatment of organophosphate-induced poisoning is based mainly on atropine and an oxime. Prompt anticonvulsive intervention is usually also required to terminate the ensuing seizure activity and to prevent delayed permanent brain damage. Midazolam, a water-soluble benzodiazepine agonist, has the advantage of rapid absorption following intramuscular administration. In mass casualty situations, the availability of an autoinjector, filled with midazolam, might be a further advantage. In the present study, the plasma pharmacokinetics of midazolam after administration by an autoinjector was compared with conventional intramuscular (i.m.) administration in two groups of four pigs each. During the first 15 min after injection, significantly higher plasma concentrations of midazolam were detected following autoinjector administration, compared with the i.m. injection. The physiological reflection of the accelerated midazolam absorption was a marked reduction in the time interval required for muscle relaxation, induced by midazolam. It is concluded that a midazolam autoinjector might be helpful in the mass casualty scenario following organophosphate poisoning.