SVCT2 Expression and Function in Reactive Astrocytes Is a Common Event in Different Brain Pathologies

Ascorbic acid (AA), the reduced form of vitamin C, acts as a neuroprotector by eliminating free radicals in the brain. Sodium/vitamin C co-transporter isoform 2 (SVCT2) mediates uptake of AA by neurons. It has been reported that SVCT2 mRNA is induced in astrocytes under ischemic damage, suggesting that its expression is enhanced in pathological conditions. However, it remains to be established if SVCT expression is altered in the presence of reactive astrogliosis generated by different brain pathologies. In the present work, we demonstrate that SVCT2 expression is increased in astrocytes present at sites of neuroinflammation induced by intracerebroventricular injection of a GFP-adenovirus or the microbial enzyme, neuraminidase. A similar result was observed at 5 and 10 days after damage in a model of traumatic injury and in the hippocampus and cerebral cortex in the in vivo kindling model of epilepsy. Furthermore, we defined that cortical astrocytes maintained in culture for long periods acquire markers of reactive gliosis and express SVCT2, in a similar way as previously observed in situ. Finally, by means of second harmonic generation and 2-photon fluorescence imaging, we analyzed brain necropsied material from patients with Alzheimer’s disease (AD), which presented with an accumulation of amyloid plaques. Strikingly, although AD is characterized by focalized astrogliosis surrounding amyloid plaques, SVCT2 expression at the astroglial level was not detected. We conclude that SVCT2 is heterogeneously induced in reactive astrogliosis generated in different pathologies affecting the central nervous system (CNS).     

Photodynamic inactivation of multiresistant bacteria (KPC) using zinc(II)phthalocyanines

The worldwide increase in antibiotic resistance has led to search of alternatives anti-microbial therapies such as photodynamic inactivation. The aim of this paper was to evaluate the photodynamic activity in vitro of a neutral and two cationic Zn phthalocyanines. Their photokilling activity was tested on Escherichia coli ATCC 25922 and Klebsiella pneumoniae Carbapenemase (KPC)-producing. After treating bacteria with phthalocyanines, the cultures were irradiated with white light. As a result, the bacteria were inactivated in presence of cationic phthalocyanines. The photoinactivation was dependent of the irradiation time and phthalocyanine concentration. The most effective photosensitizer on KPC-producing was Zinc(II)tetramethyltetrapyridino[2,3-b:2′,3′-g:2″,3″-l:2?,3?-q]porphyrazinium methylsulfate (ZnTM2,3PyPz). After irradiation using the water soluble ZnTM2,3PyPz (3 μM) the viability of KPC (30 min of irradiation) and E. coli (10 min of irradiation) decreased ≈99.995%.     

Reproductive pattern of the freshwater prawn Pseudopalaemon bouvieri (Crustacea,Palaemonidae) from hypo-osmotic shallow lakes of Corrientes (Argentina)

Pseudopalaemon bouvieri undergoes complete abbreviated development. The reproductive cycle (proportion and size of the sexually mature population and juvenile recruitment), fecundity and egg size of this prawn were examined in three subtropical shallow lakes. The reproductive cycle was seasonal; gonadal maturation occurred during the winter, ovigerous females were abundant in the spring and breeding occurred at the end of spring. Females produced small numbers of eggs (9–55) of relatively large sizes (1.0–2.1 mm). The proportion of ovigerous females with respect to the total number of females, the fecundity and egg size differed among the lakes according to the trophic state of the environments. Pseudopalaemon bouvieri has a reproductive strategy similar to other Palaemonidae species that inhabit nutrient-poor inland waters.     

Preliminary study of mother–offspring conflict in black and gold howler monkeys (<Emphasis Type="Italic">Alouatta caraya</Emphasis>)

Parent–offspring conflict has been scarcely studied in Neotropical primates. In this study, we explored mother–offspring conflict in a group of wild black and gold howler monkeys (Alouatta caraya) in northeastern Argentina. We used the all-occurrences technique to record behaviors, completing 712 h of observation. The results showed that all immature individuals between 2 and 23 months expressed conflict with regard to suckling or traveling with their mothers. Successful suckling attempts negatively correlated with the age of the immatures, occurring least frequently with the presence of newborns. In the juvenile period, the decline in successful attempts was a consequence of juveniles reducing suckling attempts and mother rejection.     

Low dose of bisphenol A impairs the reproductive axis of prepuberal male rats

The objective of the present work was to study the effect of a low dose of bisphenol A (BPA), on the reproductive axis of prepuberal male rats exposed to the endocrine disruptor (ED) during gestation and lactation period. Wistar-mated rats were treated with either 0.1 % ethanol or BPA in their drinking water until their offspring were weaned at the age of 21 days. The estimated average dose of exposure to dams was approximately 3 μg/kg/day of BPA. The pups were sacrificed on the 35th day of life. Body weight was measured during the development and at the moment of the sacrifice; testicular and seminal vesicles weight and their respective relative weights were also measured. LH, FSH and testosterone were determined and histological studies of testicular tissue were also performed. Body weight at the moment of the sacrifice was significantly higher in the group exposed to BPA; testicular weight decreased significantly; seminal vesicles weight and relative weights of testes and seminal vesicles were not modified by treatment. LH and FSH serum levels increased significantly after treatment, meanwhile testosterone showed no significant changes. Histological studies showed the lumen of seminal tubes reduced by the presence of immature cells of the spermatic lineage. Our results suggest that pre- and early postnatal exposure to a low dose of BPA disrupts the normal function of the reproductive axis in prepuberal male rats. The effects of the ED may be exerted at different levels of the axis and may be dependent on the dose, manner of administration, and the moment of exposure to the disruptor.     

Exploration of the Production of Three Thiodiketopiperazines by an Endophytic Fungal Strain of Cophinforma mamane

Endophytic fungi possess a versatile metabolism which is related to their ability to live in diverse ecological niches. While culturing under laboratory conditions, their metabolism is mainly influenced by the culture media, time of incubation and other physicochemical factors. In this study, we focused on the production of 3 thiodiketopiperazines (TDKPs) botryosulfuranols A−C produced by an endophytic strain of Cophinforma mamane isolated from the leaves of Bixa orellana L collected in the Peruvian Amazon. We studied the time-course production of botryosulfuranols A−C during 28 days and evaluated the variations in the production of secondary metabolites, including the TDKPs, produced by C. mamane in response to different culture media, light versus dark conditions and different incubation times. We observed a short time-frame production of botryosulfuranol C while its production was significantly affected by the light conditions and nutrients of the culture media. Botryosulfuranols A and B showed a similar production pattern and a similar response to culturing conditions. Molecular networking allowed us to detect three compounds related to TDKPs that will be the focus of future experiments.     

Climate mediates roles of pollinator species in plant–pollinator networks

Aim

Understanding how climate conditions influence plant–pollinator interactions at the global scale is crucial to understand how pollinator communities and ecosystem function respond to environmental change. Here, we investigate whether climate drives differences in network roles of the main insect pollinator orders: Diptera, Coleoptera, Lepidoptera and Hymenoptera.

Location

Global.

Time period

1968–2020.

Major taxa studied

Diptera, Coleoptera, Lepidoptera and Hymenoptera.

Methods

We collated plant–pollinator networks from 26 countries and territories across the five main Köppen–Geiger climate zones. In total, we compiled data from 101 networks that included >1500 plant species from 167 families and >2800 pollinator species from 163 families. We assessed differences in the composition of plant–pollinator interactions among climate zones using a permutational ANOVA. We calculated standard network metrics for pollinator taxonomic groups and used Bayesian generalized mixed models to test whether climate zone influenced the proportion of pollinator network links and the level of pollinator generalism.

Results

We found that climate is a strong driver of compositional dissimilarities between plant–pollinator interactions. Relative to other taxa, bees and flies made up the greatest proportion of network links across climate zones. When network size was accounted for, bees were the most generalist pollinator group in the tropics, whereas non-bee Hymenoptera were the most generalist in arid zones, and syrphid flies were the most generalist in polar networks.

Main conclusions

We provide empirical evidence at the global scale that climate strongly influences the roles of different pollinator taxa within networks. Importantly, non-bee taxa, particularly flies, play central network roles across most climate zones, despite often being overlooked in pollination research and conservation. Our results identify the need for greater understanding of how global environmental change affects plant–pollinator interactions.     

Genetic assignment and monitoring of yellow cardinals

The yellow cardinal (Gubernatrix cristata) is a passerine bird endemic to southern South America. At present, the species is threatened with extinction, in part because of the capture of wild birds to supply the illegal caged-bird market. Previous genetic evidence supports the existence of 3 management units for the species in Argentina, where the largest populations are currently found. Our objectives were to guide the reintroduction of these animals to their respective management units by determining the origin of seized specimens from illegal trade using 2 molecular markers, mtDNA and microsatellites, and to monitor the success of the released birds through radio-telemetry. We compared the performance of different molecular markers and assignment approaches to optimize a technique capable of assigning the origin of confiscated yellow cardinals in a reliable way. Five of 10 released radio-tracked individuals were predated shortly after liberation; however, 3 were successful in finding a mate and starting reproductive activities. Individual success was independent of the time spent in captivity, the liberation with a partner, the settlement type (semi-open or closed), and the maximum distance traveled from the point of release. Cardinals that survived had higher individual heterozygosity. Our findings contribute a robust genetic assignment technique to be used in future yellow cardinal seizures and identify factors that might improve subsequent releases. © 2019 The Wildlife Society.