183 research outputs found

    Affordable optical clearing and immunolabelling in mouse brain slices

    Get PDF
    Traditional histological analysis is conducted on thin tissue sections, limiting the data capture from large tissue volumes to 2D profiles, and requiring stereological methods for 3D assessment. Recent advances in microscopical and tissue clearing methods have facilitated 3D reconstructions of tissue structure. However, staining of large tissue blocks remains a challenge, often requiring specialised and expensive equipment to clear and immunolabel tissue. Here, we present the Affordable Brain Slice Optical Clearing (ABSOC) method: a modified iDISCO protocol which enables clearing and immunolabeling of mouse brain slices up to 1 mm thick using inexpensive reagents and equipment, with no intensive expert training required. We illustrate the use of ABSOC in 1 mm C57BL/6J mouse coronal brain slices sectioned through the dorsal hippocampus and immunolabelled with an anti-calretinin antibody. The ABSOC method can be readily used for histological studies of mouse brain in order to move from the use of very thin tissue sections to large volumes of tissue - giving more representative analysis of biological samples, without the need for sampling of small regions only

    Consumo de substâncias psicoativas por adolescentes escolares de Ribeirão Preto, SP (Brasil). I - Prevalência do consumo por sexo, idade e tipo de substância

    Get PDF
    INTRODUÇÃO: A preocupação suscitada quanto ao consumo de substâncias psicoativas pelos adolescentes tem mobilizado grandes esforços em todo o mundo na produção de conhecimento sobre este fenômeno. Decidiu-se estudar as taxas de prevalência de consumo de substâncias psicoativas de uso lícito e ilícito, sua distribuição por idade, sexo e a idade da primeira experiência com essas substâncias, entre adolescentes escolares do Município de Ribeirão Preto, SP, Brasil. MATERIAL DE MÉTODO: Um questionário devidamente adaptado e submetido a um teste de confiabilidade foi auto-aplicado a uma amostra proporcional de 1.025 adolescentes matriculados na oitava série do primeiro grau e primeiro, segundo e terceiro anos do segundo grau, das escolas públicas e privadas do município estudado. O questionário continha questões sobre o uso de dez classes de substâncias psicoativas, questões demográficas e informações de validação, além de questões de percepção e comportamento intrínseco ao consumo de drogas. RESULTADOS: Da amostra 88,9% consumiram bebidas alcoólicas alguma vez na vida; 37,7% utilizaram o tabaco; 31,1% os solventes; 10,5% os medicamentos; 6,8% a maconha; 2,7% a cocaína; 1,6% os alucinógenos e 0,3% consumiu alguma substância a base de opiácios. As taxas de consumo cresceram com a idade, para todas as substâncias; no entanto, o uso de tabaco e de substâncias ilícitas mostrou uma desaceleração nos anos que compreendem o final da adolescência. Verificou-se que os meninos consumiram mais do que as meninas, exceto para os medicamentos, com as meninas consumindo barbitúricos, anfetaminas e tranqüilizantes em proporções semelhantes ou maiores que os meninos. A idade da primeira experiência mostrou que o acesso às substâncias psicoativas ocorreu em idades bastante precoces. CONCLUSÕES: As substâncias psicoativas, sejam lícitas ou ilícitas, são freqüentemente experimentadas na adolescência, tanto pelos meninos como pelas meninas, muitas vezes em idades bem precoces.INTRODUCTION: Concern over the consumption of psychoactive substances by teenagers has given rise to a great wordwide effort to produce information about this phenomenon. This study set out to investigate the prevalence of consumption of legal and illegal psychoactive substances, its distribution by age, sex and age at first experience of them, among teenage pupils in county, Ribeirão Preto, SP, Southeastern Brazil. MATERIAL AND METHOD: A self-applicable questionnaire duly adapted and submitted to a reliability test was applied to a proportional sample of 1,025 teenagers enrolled in 8th, 9th, 10th and 11th grads at public and private city schools. The questionnaire contained questions about the use of ten classes of psychoactive substances, demographic questions and validation information, as well as questions about the perception and intrinsic behavior related to drug consumption. RESULTS: The sample of 88.9% had consumed alcoholic beverages sometime in their lives, 37.7% had used tobacco, 31.1% solvents, 10.5% medicines, 6.8% marihuana, 2.7% cocaine, 1.6% hallucinogens, and 0.3% of the sample had consumed some opiate substance. The rates of consumption increased with age for all substances; however, the use of tobacco and of illegal substances was less intense during the later years of adolescence. As to sex distribution, boys consumed more than girls, except for medicines, with girls consuming barbiturates, amphetamines and tranquilizers in proportions similar to or higher than those observed among boys. Age at first experience showed that access to psychoactive substances occurred at very early ages. CONCLUSIONS: Experimenting with psychoactive substances, whether legal or illegal, is a frequent phenomenon during adolescence, both among boys and girls, often at very early ages

    Consumo de substâncias psicoativas por adolescentes escolares de Ribeirão Preto, SP (Brasil): II - Distribuição do consumo por classes sociais

    Get PDF
    INTRODUCTION: Many of the epidemiological studies on the consumption of legal and illegal psychoactive substances have included the evaluation of the influence of social context on the levels of prevalence of this consumption using indirect social indicators such as family income, and educational and housing levels in an attempt to identify individuals or groups in different social contexts. The present study investigates the distribution of consumpition of psychoactive substances according to social class in a sample of teenage pupils in Ribeirão Preto, SP, Southeastern Brazil. MATERIAL AND METHOD: A self-applicable questionnaire duly adapted and submitted to a reliability test was applied to a proportional sample of 1,025 teenagers enrolled in the 8th, 9th, 10th and 12th grades in public and private city schools. The questionnaires contained questions about the use of ten classes of psychoactive substances, demographic questions and validation information, as well as questions about the perception and intrinsic behavior related to drug consumption. The adaptation of a model that identifies 5 social class strata (business middle class, managerial middle class, lower middle class, proletariat and subproletariat) on the basis of indicators that situate the individuals within the social relations of production, was used. RESULTS: The 3 middle class strata were more often represented, whereas the proletariat and subproletariat were less frequently represented in this teenage pupil population than in the population in general. There was no difference in alcohol or tobacco consumption according to social class, although prevalence tended to be higher at the two extremes of the social ladder. In contrast, the consumption of illegal substances was higher in the middle class and lower in the proletariat. CONCLUSION: Although the consumption of legal substances did not differ among social classes, the higher consumption of illegal substances by the wealthier teenagers was probably due to the higher cost of these products as compared those of alcohol and tobacco.INTRODUÇÃO: Vários estudos epidemiológicos sobre o consumo de substâncias psicoativas têm incluído em suas análises a avaliação da influência do contexto social nos níveis de prevalência desse consumo. Analisa-se a distribuição do consumo dessas substâncias segundo as classes sociais, numa amostra de adolescentes escolares de Ribeirão Preto, SP, Brasil. MATERIAL E MÉTODO: Um questionário auto-aplicável, adaptado e submetido a um teste de confiabilidade, foi aplicado a uma amostra proporcional de 1.025 adolescentes matriculados na oitava série do primeiro grau e primeiro, segundo e terceiro anos do segundo grau, das escolas públicas e privadas da cidade. O questionário continha questões sobre o uso de dez classes de drogas. Utilizou-se a adaptação de um modelo que identifica 5 frações de classe social (burguesias empresarial, gerencial e pequena burguesia, proletariado e subproletariado), a partir de indicadores que situam os indivíduos dentro das relações sociais de produção. RESULTADOS: As três frações da burguesia foram mais representadas que as outras na população de adolescentes escolares do que na população geral. Não houve diferenças na distribuição do consumo de álcool e tabaco pelas classes sociais, embora se observe uma tendência de maior prevalência nos extremos da escala social. Já o consumo de substâncias ilícitas foi maior nas burguesias e menor no proletariado. CONCLUSÕES: Embora o consumo de substâncias lícitas não tenha diferido entre as classes sociais, o maior consumo de substâncias ilícitas pelos mais ricos provavelmente se deveu ao maior custo desses produtos do que o álcool e o tabaco

    Acute Mountain Sickness Symptoms Depend on Normobaric versus Hypobaric Hypoxia

    Get PDF
    Acute mountain sickness (AMS), characterized by headache, nausea, fatigue, and dizziness when unacclimatized individuals rapidly ascend to high altitude, is exacerbated by exercise and can be disabling. Although AMS is observed in both normobaric (NH) and hypobaric hypoxia (HH), recent evidence suggests that NH and HH produce different physiological responses. We evaluated whether AMS symptoms were different in NH and HH during the initial stages of exposure and if the assessment tool mattered. Seventy-two 8 h exposures to normobaric normoxia (NN), NH, or HH were experienced by 36 subjects. The Environmental Symptoms Questionnaire (ESQ) and Lake Louise Self-report (LLS) were administered, resulting in a total of 360 assessments, with each subject answering the questionnaire 5 times during each of their 2 exposure days. Classification tree analysis indicated that symptoms contributing most to AMS were different in NH (namely, feeling sick and shortness of breath) compared to HH (characterized most by feeling faint, appetite loss, light headedness, and dim vision). However, the differences were not detected using the LLS. These results suggest that during the initial hours of exposure (1) AMS in HH may be a qualitatively different experience than in NH and (2) NH and HH may not be interchangeable environments
    corecore