Karyotypic study of some species of Serjania and Urvillea (Sapindaceae; Tribe Paullinieae)

Karyotypes of six species (in ten populations) of the genus Serjania and one species of the genus Urvillea were studied using root tip mitotic metaphases. All species of Serjania were diploids with 2n = 24 chromosomes and the species of Urvillea was octoploid with 2n = 86 chromosomes. Analysis of the karyotypes of Serjania showed that the species are differentiated by chromosomic structural changes. Chromosome lengths showed great differences among the species that may be explained by chromosomal deletion or addition. The basic chromosomic number is x = 12 for Serjania and x = 11 for Urvillea. In Urvillea the evolutionary trend may be toward polyploidy followed by reductional aneuploidy. The Giemsa (C-band) staining technique was applied in Serjania; however, no clear blocks of heterochromatin were observed. This result agrees with the presence of semireticulate nuclei. The Nucleolar Organizing Region (NOR-banding) technique was applied in S. communis and S. laruotteana, which showed one and two pairs stained, respectively. Variation in the number of nucleoli was observed among the different populations of Serjania. This variation could be explained by the presence of small nucleolar organizer regions that occur scattered along the genome and are not detected by the silver staining methodology.     

Diphenyl Ditelluride Induces Anxiogenic-Like Behavior in Rats by Reducing Glutamate Uptake

Anxiety-related disorders are a common public health issue. Several lines of evidence suggest that altered glutamatergic neurotransmission underlies anxiety. The present study evaluated the effect of diphenyl ditelluride [(PhTe)₂] exposure on the behavioral performance of rats and examined whether the behavioral effects could be attributed to changes in the modulation of glutamatergic function. Rats were exposed to (PhTe)₂ (subcutaneously) during 8 weeks—final dose one third LD₅₀ (124 μg/kg). The testing schedule included elevated plus-maze, open-field, T-maze, rotorod, and Morris water maze tests. Synaptosomal basal [³H] glutamate release and uptake were also evaluated. The time spent in the open arm and the ratio of time spent in the open arm/total were decreased in the (PhTe)₂ group. Furthermore, the [³H] glutamate uptake was decreased in this experimental group. The results suggest that exposure to (PhTe)₂ did not change motor abilities whereas it may result in anxiogenic-like behavior, induced by changes in the glutamatergic system at the pre-synaptic level.     

Diet of the snake Philodryas nattereri (Steindachner, 1870) suggests a high plasticity of foraging in north-eastern Brazil

The knowledge about interactions between predators and prey is essential for understanding the natural history of animals, especially snakes, which are cryptic organisms that are difficult to visualize in the wild. This article reports on the predation of lizards, frogs, bats and venomous snakes by the snake Philodryas nattereri, evidencing its generalist feeding habits.     

APM/CD13 and FOS in the hypothalamus of monosodium glutamate obese and food deprived rats

Protein (western blotting) and gene (PCR) expressions, catalytic activity of puromycin-insensitive membrane-bound neutral aminopeptidase (APM/CD13) and in situ regional distribution of CD13 and FOS immunoreactivity (ir) were evaluated in the hypothalamus of monosodium glutamate obese (MSG) and/or food deprived (FD) rats in order to investigate their possible interplay with metabolic functions. Variations in protein and gene expressions of CD13 relative to controls coincided in the hypothalamus of MSG and MSG-FD (decreased 2- to 17-fold). Compared with controls, the reduction of hypothalamic CD13 content reflected a negative balance in its regional distribution in the supraoptic, paraventricular, periventricular and arcuate nuclei. CD13-ir increased in the supraoptic nucleus in MSG (2.5-fold) and decreased in the paraventricular nucleus (2-fold) together with FOS-ir (1.5-fold) in FD. In MSG-FD, FOS-ir decreased (7-fold) in the paraventricular nucleus, while CD13-ir decreased in the periventricular (5.6-fold) and the arcuate (3.7-fold) nuclei. It was noteworthy that all these changes of CD13 were not related to catalytic activity of APM. Data suggested that hypothalamic CD13 plays a role in the regulation of energy metabolism not by means of APM enzyme activity.     

Fitness aspects of transgenic <Emphasis Type="Italic">Aedes fluviatilis</Emphasis> mosquitoes expressing a <Emphasis Type="Italic">Plasmodium</Emphasis>-blocking molecule

Vector-born diseases cause millions of deaths every year globally. Alternatives for the control of diseases such as malaria and dengue fever are urgently needed and the use of transgenic mosquitoes that block parasite/virus is a sound strategy to be used within control programs. However, prior to use transgenic mosquitoes as control tools, it is important to study their fitness since different biological aspects might influence their ability to disseminate and compete with wild populations. We previously reported the construction of four transgenic Aedes fluviatilis mosquito lines expressing a Plasmodium- blocking molecule (mutated bee venom phospholipase A₂–mPLA₂). Presently we studied two aspects of their fitness: body size, that has been used as a fitness-related status, and the expression of major enzymes classes involved in the metabolism of xenobiotics, including insecticides. Body size analysis (recorded by geometric wing morphometrics) indicated that both male and female mosquitoes were larger than the non-transgenic counterparts, suggesting that this characteristic might have an impact on their overall fitness. By contrast, no significant difference in the activity of enzymes related to metabolic insecticide resistance was detected in transgenic mosquitoes. The implication on fitness advantage of these features, towards the implementation of this strategy, is further discussed.     

Comparison of the Antioxidant Properties and the Toxicity of <Emphasis Type="Italic">p</Emphasis>,<Emphasis Type="Italic">p</Emphasis>′-Dichlorodiphenyl Ditelluride with the Parent Compound,Diphenyl Ditelluride

The hypothesis to be tested in this study is whether the introduction of the chloro group into diphenyl ditelluride molecule (p,p′-dichlorodiphenyl ditelluride, compound 1b) alters the antioxidant and scavenging activity of diphenyl ditelluride (compound 1a) in vitro. The results revealed that 1a and 1b had a potent antioxidant activity in vitro. However, the introduction of a functional group, chloro, into diphenyl ditelluride molecule (1b) did not cause great alterations in the antioxidant action of diphenyl ditelluride against lipid peroxidation, protein carbonyl, and scavenging of 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) and 2,2′-diphenyl-1-picrylhydrazyl radicals. Based on the in vitro results, different doses (0.25 and 0.75 μmol/kg) of 1a and 1b or vehicle (canola oil, 1 ml/kg) were administered to rats to investigate if the presence of chloro into diphenyl ditelluride molecule reduces its toxicity. The data demonstrate that the chloro group introduced into diphenyl ditelluride molecule did not alter the acute oral toxicity in rats. The administration of compound 1a in rats only altered the urea level, while compound 1b caused alterations in all toxicological parameters analyzed (alanine aminotransferase and aspartate aminotransferase activities, urea and creatinine levels) in plasma of rats. The results of the present investigation support similar antioxidant and scavenging activities of 1a and 1b in rat liver homogenate in vitro. Furthermore, the presence of chloro into diphenyl ditelluride molecule did not alter the mortality index but increased toxicity of diphenyl ditelluride in rats.     

Intranasal Administration of the Dopaminergic Agonists l-DOPA, Amphetamine, and Cocaine Increases Dopamine Activity in the Neostriatum: A Microdialysis Study in the Rat

Abstract: The effectiveness of intranasal drug administration to stimulate central neuronal systems is well known from drug addiction and has also been considered as an alternative pharmacokinetic approach to treat brain disorders such as Parkinson's disease. In the present study, the possible neurochemical effects of intranasal administration of the psychostimulants cocaine and amphetamine and of the antiparkinsonian drug l -DOPA were analyzed. By using in vivo microdialysis in the urethane-anesthetized rat, it was found that unilateral intranasal administration of either of the psychostimulants led to huge and rapid increases of extracellular dopamine levels in the neostriatum followed by decreases of its metabolites dihydroxyphenylacetic acid and homovanillic acid. Furthermore, intranasal administration of l -DOPA, but not of the saline vehicle, also led to increased extracellular levels of neostriatal dopamine and to increases of its metabolites. Because the effect of intranasal l -DOPA on neostriatal dopamine was observed only ipsilaterally but not contralaterally to the side of intranasal drug administration, it can be hypothesized that l -DOPA was not effective via passage through the circulation but may have acted through a neuronal or an extraneuronal route. These data provide neurochemical evidence that the intranasal route may not only be efficient in drug abuse, but may also be useful to target the brain therapeutically, as in the case of neurodegenerative brain disorders.     

Proteomic analysis of kidney in rats chronically exposed to fluoride

Two-dimensional gel electrophoresis (2-DE) was used to better understand alterations in renal metabolism induced by fluoride (F). Three groups of weanling male Wistar rats were treated with drinking water containing 0 (control), 5, or 50 ppm F for 60 days (n = 6/group). Kidneys were collected for proteomic and histological (HE) analysis. After protein isolation, renal proteome profiles were examined using 2-DE and Colloidal Coomassie Blue staining. Protein spots with a 2-fold significant difference as detected by quantitative intensity analysis (Image Master Platinum software) and t-test (p < 0.05) were excised and analyzed by MALDI-TOF MS (matrix assisted laser desorption ionization-time-of-flight mass spectrometry). The histological analysis revealed no damage in kidneys induced by F, except for a vascular congestion in the 50 ppm F group. Between control vs 50 ppm F, and control vs 5 ppm F groups, 12 and 6 differentially expressed proteins were detected, respectively. Six proteins, mainly related with metabolism, detoxification and housekeeping, were successfully identified. At the high F group, pyruvate carboxylase, a protein involved in the formation of oxaloacetate was found to be downregulated, while enoyl coenzyme A hydratase, involved in fatty acids oxidation, was found to be upregulated. Thus, proteomic analysis can provide new insights into the alterations in renal metabolism after F exposure, even in low doses.