Efeito do fotoperíodo na sobrevivência de larvas da tilápia nilótica (Oreochromis Niloticus) submetidas a diferentes fotoperíodos / Effect of photoperious on survival of nilotic tilapia larvae (Oreochromis Niloticus) submitted to different photoperiouses

A tilápia tornou-se o peixe mais importante e significativo na produção de pescados do Brasil, observando tal importância, muito tem se pesquisado objetivando melhorar ainda mais o desempenho do animal. Neste sentido, o objetivo deste trabalho foi avaliar o efeito do fotopeíodo na sobrevivência de larvas de tilápia Nilótica (Oreochromis niloticus) submetidas a diferentes fotoperíodos (12/12h claro:escuro, 18/06h claro:escuro e 24h claro controlado, C:E, C1:E1, C:C, respectivamente) durante 7 dias de experimento. Para tanto, montou-se um sistema de recirculação com 9 caixas d`água de polietileno (1000l/cada), sendo 3 caixas para cada fotoperíodo, as quais continham 2 incubadoras de garrafa PET cada, sendo estas povoadas com 111 ovos. Tendo assim, um total 1.998 embriões. Os parâmetros de qualidade da água mantiveram-se dentro da normalidade. Para análise da sobrevivência realizou-se o teste do Qui-quadrado, a fim de verificar as frequências absoluta, relativa e possíveis diferenças entre os fotoperíodos e dias. Contudo, não observou-se diferença estatística entre os fotoperíodos C:E, C1:E1 e C:C (p<0,4990), mas entre os dias (p<0,0001), com uma alta taxa de mortalidade entre os dias, precisamente no 2º dia. Assim, não foi observado diferença estatisticamente significativa entre os fotoperíodos na sobrevivência das larvas durante uma semana de cultivo

Insulin-like growth factor (IGF) signalling and genome-wide transcriptional regulation in fast muscle of zebrafish following a single-satiating meal

SUMMARY Male zebrafish (Danio rerio) were fasted for 7 days and fed to satiation over 3 h to investigate the transcriptional responses to a single meal. The intestinal content at satiety (6.3% body mass) decreased by 50% at 3 h and 95% at 9 h following food withdrawal. Phosphorylation of the insulin-like growth factor (IGF) signalling protein Akt peaked within 3 h of feeding and was highly correlated with gut fullness. Retained paralogues of IGF hormones genes were regulated with feeding, with igf1a showing a pronounced peak in expression after 3 h and igf2b after 6 h. Igf-I receptor transcripts were markedly elevated with fasting, and decreased to their lowest levels 45 min after feeding. igf1rb transcripts increased more quickly than igf1ra transcripts as the gut emptied. Paralogues of the insulin-like growth factor binding proteins (IGFBPs) were constitutively expressed, except for igfbp1a and igfbp1b transcripts, which were significantly elevated with fasting. Genome-wide transcriptional responses were analysed using the Agilent 44K oligonucleotide microarray and selected genes validated by qPCR. Fasting was associated with the upregulation of genes for the ubiquitin-proteasome degradation pathway, anti-proliferative and pro-apoptotic genes. Protein chaperones (unc45b, hspd1, hspa5, hsp90a.1, hsp90a.2) and chaperone interacting proteins (ahsa1 and stip1) were upregulated 3 h after feeding along with genes for the initiation of protein synthesis and mRNA processing. Transcripts for the enzyme ornithine decarboxylase 1 showed the largest increase with feeding (11.5-fold) and were positively correlated with gut fullness. This study demonstrates the fast nature of the transcriptional responses to a meal and provides evidence for differential regulation of retained paralogues of IGF signalling pathway genes.</jats:p

Molecular and clinical epidemiological surveillance of dengue virus in Paraíba, Northeast Brazil

ABSTRACT INTRODUCTION: Despite being the most prevalent arboviral disease worldwide, dengue has been neglected lately. However, recent epidemics of arboviruses such as Zika and chikungunya in locations throughout the world have alerted health authorities to these diseases. This study evaluated the incidence pattern of dengue, its clinical characteristics, and co-circulation of serotypes from 2007 to 2015 in Paraiba State, Northeast Brazil. METHODS: Data on dengue cases from 2007 to 2015 were extracted from clinical reports of the National System for Notifiable Diseases [Sistema Nacional de Agravos de Notificação (SINAN)] of Brazil provided by the Paraiba Health Department. Reverse transcription polymerase chain reaction (RT-PCR) assays for dengue serotypes were carried out on plasma samples obtained from patients with suspected dengue. The data were analysed using descriptive statistics. RESULTS: According to clinical features, dengue fever [n = 39,083 (70.2%)] and dengue without warning signs [n = 15,365 (27.7%)] were the most common classifications of dengue. On RT-PCR, DENV 1 was the most commonly identified serotype (80.5%) in all years studied. Co-circulation of all four DENV serotypes was observed in 2013 and 2014. Furthermore, we observed an increase in dengue notifications in 2015, possibly due to the rise of Zika and chikungunya. CONCLUSIONS: Our findings support the hypothesis that co-circulation of the four DENV serotypes may be a reason for the increased prevalence of severe forms of dengue in the years studied. This study may contribute to directing research, health policy, and financial resources toward reducing poorly controlled epidemic diseases

Molecular and clinical epidemiological surveillance of dengue virus in Paraíba, Northeast Brazil

<div><p>ABSTRACT INTRODUCTION: Despite being the most prevalent arboviral disease worldwide, dengue has been neglected lately. However, recent epidemics of arboviruses such as Zika and chikungunya in locations throughout the world have alerted health authorities to these diseases. This study evaluated the incidence pattern of dengue, its clinical characteristics, and co-circulation of serotypes from 2007 to 2015 in Paraiba State, Northeast Brazil. METHODS: Data on dengue cases from 2007 to 2015 were extracted from clinical reports of the National System for Notifiable Diseases [Sistema Nacional de Agravos de Notificação (SINAN)] of Brazil provided by the Paraiba Health Department. Reverse transcription polymerase chain reaction (RT-PCR) assays for dengue serotypes were carried out on plasma samples obtained from patients with suspected dengue. The data were analysed using descriptive statistics. RESULTS: According to clinical features, dengue fever [n = 39,083 (70.2%)] and dengue without warning signs [n = 15,365 (27.7%)] were the most common classifications of dengue. On RT-PCR, DENV 1 was the most commonly identified serotype (80.5%) in all years studied. Co-circulation of all four DENV serotypes was observed in 2013 and 2014. Furthermore, we observed an increase in dengue notifications in 2015, possibly due to the rise of Zika and chikungunya. CONCLUSIONS: Our findings support the hypothesis that co-circulation of the four DENV serotypes may be a reason for the increased prevalence of severe forms of dengue in the years studied. This study may contribute to directing research, health policy, and financial resources toward reducing poorly controlled epidemic diseases.</p></div