Expression and pharmacological inhibition of TrkB and EGFR in glioblastoma

Molecular Biology Reports - A member of the Trk family of neurotrophin receptors, tropomyosin receptor kinase B (TrkB, encoded by the NTRK2 gene) is an increasingly important target in various...     

Donepezil Prevents Inhibition of Cerebral Energetic Metabolism Without Altering Behavioral Parameters in Animal Model of Obesity

Neurochemical Research - Obesity is characterized by chronic inflammation of low grade. The cholinergic anti-inflammatory pathway favors the reduction of the inflammatory response. In this work the...     

On the release of fluoride from biofilm reservoirs during a cariogenic challenge: an in situ study

Abstract

Biofilm fluoride reservoirs may be a source of fluoride to the fluid phase during a sugar challenge reducing tooth mineral loss. However, the evidence for that is conflicting and has not been studied in biofilms containing different fluoride levels. In order to test fluoride release from biofilms with distinct fluoride concentrations, biofilms were grown in situ exposed to a combination of placebo, calcium and fluoride rinses forming biofilms with no (fluoride-free rinses), low (fluoride-only rinses) or high (calcium followed by fluoride rinses) fluoride concentrations, and collected before and 5?min after a sucrose challenge. Rinsing with fluoride increased fluoride concentration in the biofilm (p?<?0.05), mainly when a calcium pre-rinse was used before the fluoride (p?<?0.05). However, after a sugar challenge, no significant increase in the biofilm fluid fluoride concentration was observed, even in the fluoride-rich biofilms (p?>?0.05). Fluoride-rich biofilms do not release fluoride to the fluid phase during a sugar challenge.     

Effect of Metalaxyl on the incidence and severity of Pearl millet downy mildew disease in Northern Nigeria

Pearl millet downy mildew (DM) incidence, severity and yield losses of two pearl millet varieties (local and improved) due to the disease were determined in the field. Significant differences in the disease incidence and severity were recorded in the plots sown with metalaxyl-treated seeds and those sown with non-treated seeds, indicating the efficacy of the fungicide on the fungus. Yield losses due to non-treatment of seeds with metalaxyl was 40.88 and 45.39% in a local variety and 43.00 and 18.60% in an improved variety in the 2000 and 2001 cropping seasons respectively. Significant differences between plots sown with metalaxyl-treated and those sown with non-treated seeds were obtained for other yield components such as 1000-grains weight, panicle length and weight.     

Neonatal Morphine Administration Leads to Changes in Hippocampal BDNF Levels and Antioxidant Enzyme Activity in the Adult Life of Rats

It is know that repeated exposure to opiates impairs spatial learning and memory and that the hippocampus has important neuromodulatory effects after drug exposure and withdrawal symptoms. Thus, the aim of this investigation was to assess hippocampal levels of BDNF, oxidative stress markers associated with cell viability, and TNF-α in the short, medium and long term after repeated morphine treatment in early life. Newborn male Wistar rats received subcutaneous injections of morphine (morphine group) or saline (control group), 5 μg in the mid-scapular area, starting on postnatal day 8 (P8), once daily for 7 days, and neurochemical parameters were assessed in the hippocampus on postnatal days 16 (P16), 30 (P30), and 60 (P60). For the first time, we observed that morphine treatment in early life modulates BDNF levels in the medium and long term and also modulates superoxide dismutase activity in the long term. In addition, it was observed effect of treatment and age in TNF-α levels, and no effects in lactate dehydrogenase levels, or cell viability. These findings show that repeated morphine treatment in the neonatal period can lead to long-lasting neurochemical changes in the hippocampus of male rats, and indicate the importance of cellular and intracellular adaptations in the hippocampus after early-life opioid exposure to tolerance, withdrawal and addiction.     

Secretory structures at syconia and flowers of Ficus enormis (Moraceae): A specialization at ostiolar bracts and the first report of inflorescence colleters

The fig (Ficus L.) infructescence, called syconium, is a receptacle with an apical opening, the ostiole, closed by bracts. The ostiolar bracts produce an exudate, which is rather conspicuous in some species. It has not been histochemically analyzed yet, and the structures responsible for its production are still unknown. Some wild growing species of Ficus from Brazil produce high amounts of this ostiolar exudate. Ficus enormis (Mart. ex Miq.) Miq. grows as trees or shrubs in the Atlantic rainforest. Our goal was to identify the secretory structures present in the inflorescence and, to characterize histochemically the ostiolar tissues and exudates. Syconia samples of F. enormis were processed and stained according to the usual techniques in plant anatomy. The morphological analysis revealed different types of bracts, one type specialized in secretion, another showing transitional characteristics between secretory and non-secreting bracts, and a third one being non-secreting. They are designated as secretory ostiolar bracts, transitional bracts and wall bracts. The floral bracteoles, digital-shaped colleters present in the ostiole, at the syconium axis and at the flower receptacle, were also analyzed. All have similar structure, like finger-shaped secretory trichomes. The colleters present among ostiolar bracts may contribute to production and composition of the ostiole exudate.     

Characterisation of the effects of leaf galls of Clusiamyia nitida (Cecidomyiidae) on Clusia lanceolata Cambess. (Clusiaceae): Anatomical aspects and chemical analysis of essential oil

Galls develop in different plant organs and are induced by the activity of various organisms. Some studies have investigated the ecological interactions between species of Clusia and gall-inducing insects. The goal of our study is to characterise changes in leaf anatomy caused by the activity of gall insects in Clusia lanceolata. Additionally, we also investigated the chemical composition of volatile compounds of normal leaves and those with galls to detect possible effects on the host plants. For anatomical studies, we used botanical material fixed in FAA₅₀. Transversal sections of the leaf blade were obtained from samples of leaves located on the third and fourth nodes from both male and female individuals. Material was studied from both sexes both with unaffected leaves and leaves containing galls. Fresh leaves of C. lanceolata were used for the extraction of volatile compounds, which were submitted to stem distillation using a modified Clevenger apparatus determining the oil yields subsequently (w/w). The unaffected leaves of female and male individuals of C. lanceolata exhibit similar anatomical structures. However, galls on leaves of both sexes show anatomical differences. The activity of the gall insect Clusiamyia nitida induces several changes in the foliar anatomy and the distribution of metabolic compounds in new tissues during gall development. However, the larvae are not able to induce significant changes in the volatile compounds of inflected leaves from male and female individuals.     

Diplospory and obligate apomixis in Miconia albicans (Miconieae, Melastomataceae) and an embryological comparison with its sexual congener M. chamissois

Apomixis, or asexual reproduction through seeds, has been reported for species of the tribe Miconieae, Melastomataceae, but details of the process have yet to be described. We analyzed and compared sporogenesis and gametogenesis in the apomictic Miconia albicans and the sexual M. chamissois. The results point to some differences between species, which were related to the apomictic process. In M. albicans microsporogenesis, problems during meiosis and degeneration of its products led to total pollen sterility, while M. chamissois presented normal bicellular pollen grains in the mature anther. The absence or abnormality of meiosis in M. albicans megasporogenesis led to the formation of an unreduced embryo sac and also to egg cell parthenogenesis, which gave rise to the apomictic embryo. Embryo and endosperm development were autonomous, resulting in seeds and fruits independent of pollination and fertilization. Thus, in this species, apomixis can be classified as diplosporic and obligate. In contrast, meiosis was as expected in the sexual M. chamissois, and led to the development of a reduced embryo sac. Despite the divergent pathways, many embryological characteristics were similar between the studied species and other Melastomataceae and they seem to be conservative character states for the family.     

1914G variant of BCHE gene associated with enzyme activity,obesity and triglyceride levels

Polymorphisms of butyrylcholinesterase (BChE) have been reported to be associated to weight, BMI variance and hypertriglyceridemia in adults and adolescents. The aim of the present study was to investigate the association of −116A (SNP: G/A; rs1126680) and 1914G (SNP: A/G; rs3495) variants of BCHE gene with anthropometric and biochemical variables associated with obesity in population sample of 115 individuals, from Southern Brazil. Participants were grouped in two categories: obese (BMI ≥ 30) and non-obese (BMI < 30). The 1914G allele showed significantly higher frequency in the obese group, and carriers of 1914G allele showed lower mean BChE activity when compared to 1914A carriers (p = 0.006). Higher means of BMI (p = 0.02) and triglyceride (TG; p = 0.01) were found in 1914G carriers (BMI = 27.57kg/m²; TG = 150.8 mg/dL) when compared to 1914A homozygotes (BMI = 25.55 kg/m²; TG = 107.9 mg/dL). Carriers of the −116A allele showed lower mean BChE activity than usual homozygotes, and the −116A variant was found in cis with 1914G (p < 0.0001; D′ = 1). The region of BCHE gene that contains the 1914G mutation site is target of microRNAs (miRs) and the response of BChE to glucocorticoids is especially influenced by these miRs. Therefore, it is possible that the 1914G allele can be interfering in gluconeogenesis, hyperglycemia, lipolysis and body fat distribution. This lower activity may cause an imbalance in lipid metabolism, which may lead to an increased predisposition to obesity and to a lower ability to maintain metabolic homeostasis.