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Flaviviruses (FVs) are arthropod-borne viruses of medical and veterinary importance. Numerous species of FVs have been isolated from various host; mainly humans, animals, ticks, and mosquitoes. Certain FVs are extremely host-specific; at the same time, some FVs can infect an extensive range of species. Based on published literatures, 11 species of FVs have been detected from diverse host species in Malaysia. In humans, dengue virus and Japanese encephalitis virus have been reported since 1901 and 1942. In animals, the Batu Cave virus, Sitiawan virus, Carey Island, Tembusu virus, Duck Tembusu virus, and Japanese encephalitis viruses were isolated from various species. In mosquitoes, Japanese encephalitis virus and Kunjin virus were isolated from Culex spp., while Zika virus and Jugra virus were isolated from Aedes spp. In ticks, the Langat virus was isolated from Ixodes spp. One of the major challenges in the diagnosis of FVs is the presence of sero-complexes as a result of cross-reactivity with one or more FV species. Subsequently, the distribution of specific FVs among humans and animals in a specific population is problematic to assess and often require comprehensive and thorough analyses. Molecular assays such as quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and digital droplet RT-PCR (ddRT-PCR) have been used for the differentiation of flavivirus infections to increase the accuracy of epidemiological data for disease surveillance, monitoring, and control. In situations where sero-complexes are common in FVs, even sensitive assays such as qRT-pCR can produce false positive results. In this write up, an overview of the various FV sero-complexes reported in Malaysia to date and the challenges faced in diagnosis of FV infections are presented.

The study of morpho-anatomical aspects, metabolic changes of proteins, antioxidant substances, as well as phenolic compounds in embryogenic callus (EC) and degenerative embryogenic callus (DEC) was the aim of the present investigation. Ability to form somatic embryos (SEs) was associated with the softness of the EC, which exhibited a white or creamy color and was composed of isodiametric cells containing dense cytoplasm, conspicuous nuclei and minimal vacuoles with observed mitotic activity. Furthermore, protein, reduced glutathione (GSH) and ascorbic acid (ASC) concentrations and the ratio between ASC and dehydroascorborbic acid (DHA) were increased significantly in the EC in comparison to the DEC. In addition, the phenolic extract of the EC was proved to have higher scavenging activity than the extract from the DEC. A loss of embryogenic competence in the DEC was correlated with the presence of more rigid clumps and such calli had a yellowish to brown color and no cell division could be observed in the cells of such aggregates as the cells had large vacuoles and they have very thick walls. Moreover, these morphological and anatomical observations of the DEC were accompanied by accumulations of the oxidized form of ascorbic acid (DHA), H2O2, total soluble phenolic compounds and overaccumulation of naringenin. Alternations in cellular metabolism can affect and regulate the morphogenesis of somatic embryos.

Alzheimer´s disease (AD) is the main cause of dementia in the elderly. Although activation of brain insulin signaling has been shown to be neuroprotective, to preserve memory in AD models, and appears beneficial in patients, the role of insulin-like growth factor 1 (IGF1) remains incompletely understood. We found reduced active/inactive IGF1 ratio and increased IGF1R expression in postmortem hippocampal tissue from AD patients, suggesting impaired brain IGF1 signaling in AD. Active/inactive IGF-1 ratio was also reduced in the brains of mouse models of AD. We next investigated the possible protective role of IGF1 in AD models. We used a recombinant adenoviral vector, RAd-IGF1, to drive the expression of IGF1 in primary hippocampal neuronal cultures prior to exposure to AβOs, toxins that accumulate in AD brains and have been implicated in early synapse dysfunction and memory impairment. Cultures transduced with RAd-IGF1 showed decreased binding of AβOs to neurons and were protected against AβO-induced neuronal oxidative stress and loss of dendritic spines. Significantly, in vivo transduction with RAd-IGF1 blocked memory impairment caused by intracerebroventricular (i.c.v.) infusion of AβOs in mice. Our results demonstrate altered active IGF1 and IGF1R levels in AD hippocampi, and suggest that boosting brain expression of IGF1 may comprise an approach to prevent neuronal damage and memory loss in AD. Fil: Selles, Maria Clara. Universidade Federal do Rio de Janeiro; Brasil Fil: Fortuna, Juliana T. S.. Universidade Federal do Rio de Janeiro; Brasil Fil: Zappa Villar, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner"; Argentina Fil: de Faria, Yasmin P. R.. Universidade Federal de Sao Paulo; Brasil Fil: Souza, Amanda S.. Universidade Federal do Rio de Janeiro; Brasil Fil: Suemoto, Claudia K.. Universidade Federal de Sao Paulo; Brasil Fil: Leite, Renata E. P.. Universidade Federal de Sao Paulo; Brasil Fil: Rodriguez, Roberta D.. Universidade Federal de Sao Paulo; Brasil Fil: Grinberg, Lea T.. Universidade Federal de Sao Paulo; Brasil. University of California; Estados Unidos Fil: Reggiani, Paula Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner"; Argentina Fil: Ferreira, Sergio Teixeira. Universidade Federal do Rio de Janeiro; Brasil