Description of the karyotype of Rhagomys rufescens Thomas, 1886 (Rodentia, Sigmodontinae) from Southern Brazil Atlantic forest

Rhagomys rufescens (Rodentia: Sigmodontinae) is an endemic species of the Atlantic forest from Southern and Southeastern Brazil. Some authors consider Rhagomys as part of the tribe Thomasomyini; but its phylogenetic relationships remain unclear. Chromosomal studies on eight specimens of Rhagomys rufescens revealed a diploid number of 2n = 36 and a number of autosome arms FN = 50. GTG, CBG and Ag-NOR banding and CMA(3) /DAPI staining were performed on metaphase chromosomes. Eight biarmed and nine acrocentric pairs were found in the karyotype of this species. The X and Y chromosomes were both acrocentric. Most of the autosomes and the sex chromosomes showed positive C-bands in the pericentromeric region. The X chromosome showed an additional heterochromatic block in the proximal region of the long arm. Nucleolus organizer regions (NORs) were located in the pericentromeric region of three biarmed autosomes (pairs 4, 6 and 8) and in the telomeric region of the short arm of three acrocentrics (pairs 10, 12 and 17). CMA (3) /DAPI staining produced fluorescent signals in many autosomes, especially in pairs 4, 6, and 8. This study presents cytogenetic data of Rhagomys rufescens for the first time.     

Rural and Urban Streams: Anthropogenic Influences and Impacts on Water and Sediment Quality

The Pirapó river watershed (Paraná State, Brazil) compounds a relatively industrialized and urbanized region, undergoing great pressure from the discharge of industrial, agricultural and domestic wastes. We evaluated the environmental quality of ten streams belonging to this watershed in April and June 2008 by performing acute and chronic toxicity tests with Daphnia similis and Ceriodaphnia silvestrii from water and sediment samples. We tested the hypothesis that the streams located in urban areas are more exposed to the influence of pollutants, than those outside the city limits. In addition, we obtained the measures of physical and chemical parameters, and identified the main polluted sources. Contrary to what was expected, the rural streams were more toxic than those located in urban area. These results demonstrate that the water bodies located in rural areas are being affected by the pollution of aquatic ecosystems as far as those found in urban areas, requiring the same attention of environmental managers in relation to its monitoring. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Microcin J25 triggers cytochrome c release through irreversible damage of mitochondrial proteins and lipids

We previously showed that the antimicrobial peptide microcin J25 induced the over-production of reactive oxygen species with the concomitant release of cytochrome c from rat heart mitochondria via the opening of the mitochondrial permeability transition pore. Here, we were able to demonstrate that indeed, as a consequence of the oxidative burst, MccJ25 induces carbonylation of mitochondrial proteins, which may explain the irreversible inhibition of complex III and the partial inhibition of superoxide dismutase and catalase. Moreover, the peptide raised the levels of oxidized membrane lipids, which triggers the release of cytochrome c. From in silico analysis, we hypothesize that microcin would elicit these effects through interaction with heme c1 at mitochondrial complex III. On the other hand, under an excess of l-arginine, MccJ25 caused nitric oxide overproduction with no oxidative damage and a marked inhibition in oxygen consumption. Therefore, a beneficial anti-oxidative activity could be favored by the addition of l-arginine. Conversely, MccJ25 pro-oxidative–apoptotic effect can be unleashed in either an arginine-free medium or by suppressing the nitric oxide synthase activity.     

Impact of moisture on in vitro germination of Metarhizium anisopliae and Beauveria bassiana and their activity on Triatoma infestans

The in vitro germination of 11 Metarhizium anisopliae and 11 Beauveria bassiana isolates originating from substrates collected in rural peridomestic areas in Central Brazil where triatomines are common was tested. Conidia completed germination up to 24 h after exposure to water activity of >0.99 a_w in all isolates tested. At lower 0.93 a_w germination was delayed but conidia of most isolates germinated at high rates (>98 %) within 216 h of incubation. Activities of 2 M. anisopliae and 2 B. bassiana isolates with different patterns of germination at 0.93 a_w were tested in Triatoma infestans third instar nymphs. There was no relationship between germination kinetics in vitro at 0.93 a_w and their activity in vivo at 98, 75 and 43 % relative humidity (rh). Isolates with accelerated germination at 0.93 a_w were not more virulent at 75 and 43 % rh compared with isolates with retarded or no germination. Highest mortalities were observed at 98 % rh, and they did not exceed 25 % after 25 d incubation at lower 75 and 43 % rh. Isolates that originated from a region with an extensive annual arid period showed no adaptation to lower humidity in their activity against T. infestans.     

Neonatal handling induces alteration in progesterone secretion after sexual behavior but not in angiotensin II receptor density in the medial amygdala: implications for reproductive success

Neonatal handling affects the hypothalamus-pituitary-gonadal axis in female rats. Indeed, postnatal handling induces anovulatory estrous cycles and decreases sexual receptiveness. On the other hand, Angiotensin II (Ang II) infused into the medial amygdala (MeA) reduces sexual behavior in male and female rats. Considering this, and that gonadal steroid secretion after copulatory behavior is important for reproductive success, the purpose of the present study was to investigate whether the reduction in sexual receptiveness in neonatally handled female rats is mediated by changes in Ang II receptor density in MeA. Moreover, gonadal steroid secretion after sexual behavior was analyzed. Two groups of female Wistar rats were studied: nonhandled (pups were left undisturbed) and handled (pups were handled for 1 min once a day during the first 10 days of life). Once they were 80-85 days old in the evening of the proestrus day, sexual receptiveness was recorded and after that the animals were killed by decapitation. Trunk blood samples were collected, and plasma estradiol and progesterone were measured by radioimmunoassay. The brains were removed for Ang II receptor autoradiography in MeA. The decreased lordosis quotient in the neonatally handled group was confirmed in the present study. Neonatal handling also reduced the progesterone concentration in the plasma, but did not change the estradiol and the density of Ang II receptors in MeA. The reduced progesterone could be due to the decreased lordosis frequency of handled females. However, this decreased sexual receptiveness is not mediated by changes in Ang II receptors in MeA.     

Miltefosine in the treatment of cutaneous leishmaniasis caused by Leishmania braziliensis in Brazil: a randomized and controlled trial

Background

Cutaneous leishmaniasis (CL) is treated with parenteral drugs for decades with decreasing rate cures. Miltefosine is an oral medication with anti-leishmania activity and may increase the cure rates and improve compliance.

Methodology/Principal Findings

This study is a randomized, open-label, controlled clinical trial aimed to evaluate the efficacy and safety of miltefosine versus pentavalent antimony (Sb^v) in the treatment of patients with CL caused by Leishmania braziliensis in Bahia, Brazil. A total of 90 patients were enrolled in the trial; 60 were assigned to receive miltefosine and 30 to receive Sb^v. Six months after treatment, in the intention-to-treat analyses, the definitive cure rate was 53.3% in the Sb^v group and 75% in the miltefosine group (difference of 21.7%, 95% CI 0.08% to 42.7%, p = 0.04). Miltefosine was more effective than Sb^v in the age group of 13–65 years-old compared to 2–12 years-old group (78.9% versus 45% p = 0.02; 68.2% versus 70% p = 1.0, respectively). The incidence of adverse events was similar in the Sb^v and miltefosine groups (76.7% vs. 78.3%). Vomiting (41.7%), nausea (40%), and abdominal pain (23.3%) were significantly more frequent in the miltefosine group while arthralgias (20.7%), mialgias (20.7%) and fever (23.3%) were significantly more frequent in the Sb^v group.

Conclusions

This study demonstrates that miltefosine therapy is more effective than standard Sb^v and safe for the treatment of CL caused by Leishmania braziliensis in Bahia, Brazil.

Trial Registration

Clinicaltrials.gov Identifier {"type":"clinical-trial","attrs":{"text":"NCT00600548","term_id":"NCT00600548"}}NCT00600548     

Metarhizium anisopliae lipolytic activity plays a pivotal role in Rhipicephalus (Boophilus) microplus infection

Lipases secreted by Metarhizium anisopliae, an important biological control agent, could potentially be involved in the host infection process. Here, we present the activity profile during the host infection process and the effect of lipase activity inhibitor ebelactone B on infection. The previous treatment of spores with lipase activity inhibitor, ebelactone B, completely inhibited lipolytic activity and prevented the infection of the Rhipicephalus (Boophilus) microplus host. The results herein presented prove, for the first time, the importance of lipase activity in M. anisopliae host infection process. The filamentous fungus Metarhizium anisopliae is one of the most important and studied biological agents for the control of several arthropod pests, including the cattle tick Rhipicephalus (Boophilus) microplus. Lipases secreted by M. anisopliae could potentially be involved in the host infection process. This work presents the activity profile during the host infection process and the effect of lipase activity inhibitor ebelactone B on infection. During the course of tick exposure to spores (6-120 h) lipase activity increased from 0.03 ± 0.00 U to 0.312 ± 0.068 U using rho NP palmitate as substrate. In zymograms, bands of lipase activity were detected in ticks treated with spores without inhibitor. The previous treatment of spores with lipase activity inhibitor, ebelactone B, completely inhibited lipolytic activity, at all times specified, and prevented the infection of the R. microplus host. Spores treated with the inhibitor did not germinate on the tick, although this effect was not observed in the culture medium. The results herein presented prove, for the first time, the importance of lipase activity in M. anisopliae host infection process.     

Genetic parameters for growth performance,fillet traits,and fat percentage of male Nile tilapia (<Emphasis Type="Italic">Oreochromis niloticus</Emphasis>)

Improvement of fillet traits and flesh quality attributes are of great interest in farmed tilapia and other aquaculture species. The main objective of this study was to estimate genetic parameters for fillet traits (fillet weight and fillet yield) and the fat content of fillets from 1136 males combined with 2585 data records on growth traits (body weight at 290 days, weight at slaughter, and daily weight gain) of 1485 males and 1100 females from a third generation of the Aquaamerica tilapia strain. Different models were tested for each trait, and the best models were used to estimate genetic parameters for the fat content, fillet, and growth traits. Genetic and phenotypic correlations were estimated using two-trait animal models. The heritability estimates were moderate for the fat content of fillets and fillet yield (0.2–0.32) and slightly higher for body weight at slaughter (0.41). The genetic correlation between fillet yield and fat was significant (0.6), but the genetic correlations were not significant between body weight and fillet yield, body weight and fat content, daily weight gain and fillet yield, and daily weight gain and fat content (? 0.032, ? 0.1, ? 0.09, and ? 0.4, respectively). Based on the genetic correlation estimates, it is unlikely that changes in fillet yield and fat content will occur when using growth performance as a selection criterion, but indirect changes may be expected in fat content if selecting for higher fillet yield.