Activation of Ventral Tegmental Area 5-HT2C Receptors Reduces Incentive Motivation

FUNDING AND DISCLOSURE The research was funded by Wellcome Trust (WT098012) to LKH; and National Institute of Health (DK056731) and the Marilyn H. Vincent Foundation to MGM. The University of Michigan Transgenic Core facility is partially supported by the NIH-funded University of Michigan Center for Gastrointestinal Research (DK034933). The remaining authors declare no conflict of interest. ACKNOWLEDGMENTS We thank Dr Celine Cansell, Ms Raffaella Chianese and the staff of the Medical Research Facility for technical assistance. We thank Dr Vladimir Orduña for the scientific advice and technical assistance.Peer reviewedPublisher PD

Exciton polaritons in a cylindrical microcavity with an embedded quantum wire

Exciton-light coupling in cylindrical microcavities containing quantum wires has been treated by means of classical electrodynamics within the nonlocal dielectric response model. A typical anticrossing behavior of quasi-one-dimensional exciton-polariton modes has been obtained, as well as the weak-coupling–strong-coupling threshold. Effects of the nonradiative damping of the exciton resonance in the quantum wire on the optical response of the microcavity structure have been analyzed

Quantification of Leishmania infantum DNA in females, eggs and larvae of Rhipicephalus sanguineus

<p/> <p>Background</p> <p><it>Leishmania infantum </it>is a widespread parasite that affects dogs and humans worldwide. It is transmitted primarily by phlebotomine sand flies, but recently there has been much discussion on the role of the brown dog tick, <it>Rhipicephalus sanguineus</it>, as a potential vector for this protozoan. Recent laboratory and field investigations have contributed to this hypothesis, but a proof of the vector capacity of <it>R. sanguineus </it>has yet to be provided. Following a recent study suggesting that <it>L. infantum </it>passes transovarially from the female tick to her progeny the current study provides new evidence of the transovarial transmission of <it>L. infantum </it>in <it>R. sanguineus</it>.</p> <p>Methods</p> <p>Engorged females of <it>R. sanguineus </it>were collected from the environment in a dog shelter of southern Italy, where canine leishmaniosis is endemic. In the laboratory, 97 females that successfully laid eggs, their eggs and the originated larvae were subjected to DNA extraction and then tested by a TaqMan-based real time PCR targeting a fragment of the kinetoplast DNA (kDNA) of <it>L. infantum</it>.</p> <p>Results and conclusions</p> <p><it>L. infantum </it>kDNA was detected in engorged females, their eggs and originating larvae, with a parasite load ranging from 1.8 × 10^-4to 10.0 × 10⁰. Certainly, the current study provides further evidence on the passage of <it>L. infantum </it>from <it>R. sanguineus </it>females to their offspring. The observation of promastigote forms in larvae is necessary to definitively confirm this hypothesis, which would raise interesting questions about the possible role of ticks in the maintenance of <it>L. infantum </it>infection among dogs in certain areas.</p

Squamous cell carcinoma arising from suprapubic cystostomy: report of two cases and a narrative review of literature

Pacientes con Carcinoma de células escamosasSquamous cell carcinoma arising from Marjolin’s ulcer of the suprapubic cystostomy tract is a rare entity that usually occurs in patients with a history of spinal cord injuries and a chronic indwelling catheter. We present 2 cases of this rare entity with the clinical exams needed for diagnosis and treatment according to individual characteristics of each case. Marjolin’s ulcer is a cutaneous malignancy that arises from injured skin. The most frequent type of malignancy identified on histopathologic examination is squamous cell carcinoma (80-90%). It can develop from long-standing scars, chronic wounds, pressure ulcers, osteomyelitis, and burns. Only cases have been reported about Marjolin’s ulcer with squamous cell carcinoma at the cystostomy cite. Treatment regimens have not been standardized; cases have received individualized treatments, usually with excision, radiation, or a combination of both. There is insufficient evidence to aid in the understanding of the etiology. In addition, there is no consensus on its optimal treatment and follow-up schemes.https://orcid.org/0000-0003-1940-741Xhttps://orcid.org/0000-0003-1271-5612https://orcid.org/0000-0003-0158-504Xhttps://orcid.org/0000-0003-1877-4621https://orcid.org/0000-0001-8202-9744https://orcid.org/0000-0003-4853-3618https://orcid.org/0000-0003-0394-9644Revista Internacional - No indexadaN

Age-related changes in Drosophila midgut are associated with PVF2, a PDGF/VEGF-like growth factor

Age-associated changes in stem cell populations have been implicated in age-related diseases, including cancer. However, little is known about the underlying molecular mechanisms that link aging to the modulation of adult stem cell populations. Drosophila midgut is an excellent model system for the study of stem cell renewal and aging. Here we describe an age-related increase in the number and activity of intestinal stem cells (ISCs) and progenitor cells in Drosophila midgut. We determined that oxidative stress, induced by paraquat treatment or loss of catalase function, mimicked the changes associated with aging in the midgut. Furthermore, we discovered an age-related increase in the expression of PVF2, a Drosophila homologue of human PDGF/VEGF, which was associated with and required for the age-related changes in midgut ISCs and progenitor cell populations. Taken together, our findings suggest that PDGF/VEGF may play a central role in age-related changes in ISCs and progenitor cell populations, which may contribute to aging and the development of cancer stem cells

Two-dimensional Vortices in Superconductors

Superconductors have two key characteristics. They expel magnetic field and they conduct electrical current with zero resistance. However, both properties are compromised in high magnetic fields which can penetrate the material and create a mixed state of quantized vortices. The vortices move in response to an electrical current dissipating energy which destroys the zero resistance state\cite{And64}. One of the central problems for applications of high temperature superconductivity is the stabilization of vortices to ensure zero electrical resistance. We find that vortices in the anisotropic superconductor Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ (Bi-2212) have a phase transition from a liquid state, which is inherently unstable, to a two-dimensional vortex solid. We show that at high field the transition temperature is independent of magnetic field, as was predicted theoretically for the melting of an ideal two-dimensional vortex lattice\cite{Fis80,Gla91}. Our results indicate that the stable solid phase can be reached at any field as may be necessary for applications involving superconducting magnets\cite{Has04,Sca04,COHMAG}. The vortex solid is disordered, as suggested by previous studies at lower fields\cite{Lee93,Cub93}. But its evolution with increasing magnetic field displays unexpected threshold behavior that needs further investigation.Comment: 5 pages and 4 figures. submitted to Nature Physic

Using the MitoB method to assess levels of reactive oxygen species in ecological studies of oxidative stress

In recent years evolutionary ecologists have become increasingly interested in the effects of reactive oxygen species (ROS) on the life-histories of animals. ROS levels have mostly been inferred indirectly due to the limitations of estimating ROS from in vitro methods. However, measuring ROS (hydrogen peroxide, H2O2) content in vivo is now possible using the MitoB probe. Here, we extend and refine the MitoB method to make it suitable for ecological studies of oxidative stress using the brown trout Salmo trutta as model. The MitoB method allows an evaluation of H2O2 levels in living organisms over a timescale from hours to days. The method is flexible with regard to the duration of exposure and initial concentration of the MitoB probe, and there is no transfer of the MitoB probe between fish. H2O2 levels were consistent across subsamples of the same liver but differed between muscle subsamples and between tissues of the same animal. The MitoB method provides a convenient method for measuring ROS levels in living animals over a significant period of time. Given its wide range of possible applications, it opens the opportunity to study the role of ROS in mediating life history trade-offs in ecological settings

Effect of Biodiversity Changes in Disease Risk: Exploring Disease Emergence in a Plant-Virus System

The effect of biodiversity on the ability of parasites to infect their host and cause disease (i.e. disease risk) is a major question in pathology, which is central to understand the emergence of infectious diseases, and to develop strategies for their management. Two hypotheses, which can be considered as extremes of a continuum, relate biodiversity to disease risk: One states that biodiversity is positively correlated with disease risk (Amplification Effect), and the second predicts a negative correlation between biodiversity and disease risk (Dilution Effect). Which of them applies better to different host-parasite systems is still a source of debate, due to limited experimental or empirical data. This is especially the case for viral diseases of plants. To address this subject, we have monitored for three years the prevalence of several viruses, and virus-associated symptoms, in populations of wild pepper (chiltepin) under different levels of human management. For each population, we also measured the habitat species diversity, host plant genetic diversity and host plant density. Results indicate that disease and infection risk increased with the level of human management, which was associated with decreased species diversity and host genetic diversity, and with increased host plant density. Importantly, species diversity of the habitat was the primary predictor of disease risk for wild chiltepin populations. This changed in managed populations where host genetic diversity was the primary predictor. Host density was generally a poorer predictor of disease and infection risk. These results support the dilution effect hypothesis, and underline the relevance of different ecological factors in determining disease/infection risk in host plant populations under different levels of anthropic influence. These results are relevant for managing plant diseases and for establishing conservation policies for endangered plant species