ABSTRACT
Saxitoxin (STX) represents a marine toxin of significant concern due to its deleterious implications for aquatic ecosystems and public food safety. As a potent paralytic agent, the role of STX in obstructing voltage-gated sodium channels (VGSCs) is well-characterized. Yet, the mechanistic details underlying its low-dose toxicity remain largely enigmatic. In the current study, zebrafish embryos and larvae were subjected to subchronic exposure of graded STX concentrations (0, 1, 10, and 100 µg/L) until the 7th day post-fertilization. A tactile stimulus-based assay was employed to evaluate potential behavioral perturbations resulting from STX exposure. Both behavioral and transcription level analyses unveiled a compromised tactile response, which was found to be associated with a notable upregulation in the mRNA of two distinct VGSC isoforms, specifically the scn8aa/ab and scn1Laa/ab transcripts, even at the minimal STX dose. Notably, exposure to this lowest STX concentration also resulted in alterations in the transcriptional patterns of pivotal genes for cholinergic and GABAergic pathways, including ache and gabra1. Furthermore, STX induced a marked decrease in the levels of the neurotransmitter GABA. Our findings underscore that prolonged low-dose STX exposure during early development can significantly compromise the tactile response behavior in zebrafish. This study reveals that chronic low-dose STX exposure of developing zebrafish alters neurotransmission pathways that converge on altered tactile behavior.
ABSTRACT
OBJETIVO: Comparar o grau evolutivo da apendicite determinada pela inspeção trans-operatória com o resultado anatomopatológico, e identificar alguma relação entre a idade, grau evolutivo da apendicite aguda e o tempo de internação hospitalar. MÉTODO: Análise retrospectiva dos prontuários de 199 pacientes submetidos a apendicectomia entre o período de outubro de 2003 a agosto de 2004, quanto à idade, sexo, tempo de internação e a fase do processo inflamatório segundo anatomopatológico das peças. RESULTADOS: A análise foi possível em 182 casos. Nestes pacientes, a distribuição quanto ao sexo mostrou maior incidência em homens, com 54,4 por cento casos; a mediana da idade foi de 20 anos, sendo a faixa etária mais prevalente entre os 11-20 anos com 36,22 por cento dos casos. A mediana do tempo de internação foi de três dias. Houve uma diferença significativa do tempo de internação de acordo com a faixa etária dos pacientes, sendo que os pacientes acima de 60 anos tiveram maior tempo de internação. O anatomopatológico evidenciou 73,62 por cento casos de apendicite supurada, 13,73 por cento apendicite branca, 7,14 por cento gangrenosa, 4,49 por cento catarral e 0,54 por cento neoplásico, confirmando o diagnóstico de apendicite em 86,24 por cento. O tempo de internação e a idade não foram significativamente diferentes entre os graus evolutivos da apendicite aguda. CONCLUSÕES: A apendicite aguda ocorre com maior freqüência nos pacientes jovens e do sexo masculino. Os pacientes idosos permanecem mais tempo internados, porém não houve diferença na idade nem tempo de internação em relação aos vários graus evolutivos da apendicite.
BACKGROUND: To study appendicitis evolution grade in comparison with intraoperative inspection and pathological results. Also a relationship between age and hospital stay length is reviewed. METHODS: Retrospective analysis of 199 patients submitted to appendicectomy between October 2003 through August 2004 using: age, sex, length of hospital stay and evolution grade of inflammatory process according to pathological examination was studied. RESULTS: Analysis was possible only in 182 cases. Distribution by sex showed a higher incidence in men (54.4 percent); median age was 20 years and the most prevalent age range was between 11 - 20 years (36.22 percent). Hospital median stay length was 3 days. There was a significant difference in hospital stay length according to age and patients older than 60 years; they had the longest hospital stay length. Pathologic examination showed 73.62 percent as suppurative appendicitis, normal appendix was 13.73 percent, gangrenous was 7.14 percent, catarrhal was 4.49 percent and neoplasm was found in 0.54 percent. Diagnosis of appendicitis was confirmed in 86.24 percent. Hospital stay length and age were not significant different between acute appendicitis evolution grades. CONCLUSION: Acute appendicitis is more frequent in young male patients. Older patients stay longer in hospital; however appendicitis evolution grades showed neither correlation with age nor length of stay.
