Browsing by Author "Marques, Joana"
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- A blood-free diet to rear anopheline mosquitoesPublication . Marques, Joana; Cardoso, João CR; Félix, Rute C.; Power, Deborah; Silveira, HenriqueMalaria research requires large-scale breeding and production conditions for mosquitoes (Anopheles spp.) in captivity. The sustainable and reliable production of mosquitoes is currently inhibited by the supply of fresh vertebrate blood. Alternatives to blood are required to promote efficient control strategies for malaria and other vector borne diseases that are transmitted by blood feeding insects. With this in mind, artificial liquid diets were formulated as substitutes for fresh vertebrate blood. Herein we report a blood-free artificial liquid diet that delivers feeding rates similar to blood and mimics the physiological effects of a fresh vertebrate blood meal. The diet induces ovarian and egg maturation of Anopheles mosquitoes and also produces good larval survival and development of functional adults. The formulated blood-free liquid diet is an important advance towards sustainable mosquito breeding in captivity and will reduce the maintenance costs of mosquito colonies and eliminate the need for fresh vertebrate blood.
- Cognitive function, cerebral microbleeds, radiotherapy, and bevacizumab in survivors of pediatric brain tumorsPublication . Passos, Joao; Nzwalo, Hipólito; Marques, Joana; Azevedo, Ana; Nunes, Sofia; Salgado, DuarteWe read with great interest a recent paper published by Roddy et al showing a high (48.8%) 5-year cumulative incidence of cerebral microbleeds (CMB) and its association with cognitive dysfunction in a group with pediatric brain tumors who received cranial radiation therapy (CRT).1 We believe that exposing the association of CMB (or the associated underlying microvascular pathology) with cognitive impairment in this population will help draw attention to the importance of the topic in this specific growing population.
- Fresh-blood-free diet for rearing malaria mosquito vectorsPublication . Marques, Joana; Cardoso, João CR; Felix, Rute C.; Santana, Rosa A. G.; Guerra, Maria das Graças Barbosa; Power, Deborah; Silveira, HenriqueMosquito breeding depends on the supply of fresh vertebrate blood, a major bottleneck for large-scale production of Anopheles spp. Feeding alternatives to fresh blood are thus a priority for research, outdoor large-cage trials and control interventions. Several artificial meal compositions were tested and Anopheles oogenesis, egg laying and development into the next generation of adult mosquitoes were followed. We identified blood-substitute-diets that supported ovarian development, egg maturation and fertility as well as, low progeny larval mortality, and normal development of offspring into adult mosquitoes. The formulated diet is an effective artificial meal, free of fresh blood that mimics a vertebrate blood meal and represents an important advance for the sustainability of Anopheles mosquito rearing in captivity.
- Microbleeds and cavernomas after radiotherapy for paediatric primary brain tumoursPublication . Passos, Joao; Nzwalo, Hipólito; Valente, Mariana; Marques, Joana; Azevedo, Ana; Netto, Eduardo; Mota, Antonio; Borges, Alexandra; Nunes, Sofia; Salgado, DuarteBackground: With the expected growth and aging of the population of primary central nervous system tumours (PCNST) survivors, attention to the radiation-induced late brain injury is fundamental. Late focal hemosiderin deposition (FHD) lesions, namely microbleeds and cavernomas, are among the presumable late cerebrovascular complications associated with radiotherapy for PCNST. Objective: To explore association between PCNST radiotherapy and the occurrence FHD lesions and to address the correlation between the topographic location of these microvascular lesions with the focal radiotherapy location. Methods: Retrospective cohort study of 190 paediatric patients being followed for PCNST in a single referral ontological centre. The frequency of FHD lesions was compared between paediatric PCNST treated (n = 132) and not treated (n = 58) with brain radiation. Microbleed Anatomical Rating Scale (MARS) was used for systematic identification of these cerebrovascular lesions and to address the consistency between the topographic location of each lesion and the location of the focal radiotherapy area. Univariate analysis to address the role of variables such as tumour histology, location, gender and age of children at the beginning of radiotherapy, duration of follow-up and chemotherapy was performed. Results: FHD lesions (microbleeds and cavernomas) occurred exclusively and in a high percentage (41.6%) in PCNST survivors treated with brain radiation. Younger age at the diagnosis (p = 0.031), duration of follow-up (p = 0.010) and embryonal histology (p = 0.003) positively correlated with the occurrence FHD lesions. FHD lesions were topographically concordant with the brain focal irradiation area in 3/19 (15.8%) patients from the focal RT subgroup and in 22/111 (19.8%) patients from the WBRT plus focal RT subgroup. Conclusion: Our study, which is one of the largest to date on the topic, shows that FHD lesions are a common complication after radiotherapy for childhood PCNST. The young brain is probably more susceptible to radiation-induced late cerebrovascular injury. Diffuse small vessel disease and ceiling effect may account for the low topographic concordance we found. The clinical implications of FHD lesions in this specific population are yet to be clarified. (C) 2016 Elsevier B.V. All rights reserved.