Female Anopheles gambiae antennae: increased transcript accumulation of the mosquito-specific odorant-binding-protein OBP2

<p>Abstract</p> <p>Background</p> <p>New interventions are required to optimally and sustainably control the <it>Anopheles </it>sp. mosquitoes that transmit malaria and filariasis. The mosquito olfactory system is important in host seeking (transmission) and mate finding (reproduction). Understanding olfactory function could lead to development of control strategies based on repelling parasite-carrying mosquitoes or attracting them into a fatal trap.</p> <p>Findings</p> <p>Our initial focus is on odorant binding proteins with differential transcript accumulation between female and male mosquitoes. We report that the odorant binding protein, OBP2 (AGAP003306), had increased expression in the antennae of female vs. male <it>Anopheles gambiae </it><it>sensu stricto </it>(G3 strain). The increased expression in antennae of females of this gene by quantitative RT-PCR was 4.2 to 32.3 fold in three independent biological replicates and two technical replicate experiments using <it>A. gambiae </it>from two different laboratories. OBP2 is a member of the vast OBP superfamily of insect odorant binding proteins and belongs to the predominantly dipteran clade that includes the <it>Culex </it>oviposition kairomone-binding OBP1. Phylogenetic analysis indicates that its orthologs are present across culicid mosquitoes and are likely to play a conserved role in recognizing a molecule that might be critical for female behavior.</p> <p>Conclusions</p> <p>OBP2 has increased mRNA transcript accumulation in the antennae of female as compared to male <it>A. gambiae</it>. This molecule and related molecules may play an important role in female mosquito feeding and breeding behavior. This finding may be a step toward providing a foundation for understanding mosquito olfactory requirements and developing control strategies based on reducing mosquito feeding and breeding success.</p

Procjena predispozicijskog učinka kokcidioze na pojavu nekrotičnog enteritisa u pokusnoj infekciji tovnih pilića.

In order to asses the predisposing effect of coccidiosis to Necrotic enteritis (NE), an experimental study was conducted in broiler chicken. In the first trial (NE alone), symptoms were noticed from the 4th to 7th days post inoculation (DPI), but no mortality was recorded. In the second trial (NE primed with coccidiosis), 23 % mortality was recorded. Grossly, a maximum intestine lesions score of 2 was recorded on the 6th DPI in the first trial. In the second trial, a maximum intestine lesions score of 3.67 was recorded on the 6th DPI. Microscopically, in the first trial, the birds’ intestines from the 4th to the 7th DPI showed hyperplasia of the villi of the jejunal mucosa. In the second trial, the birds’ intestines from 2nd to 4th DPI showed severe hyperplasia of the villi, and the presence of E. necatrix schizonts within and outside the enterocytes. In the second trial, intestines from 5th to 7th DPI revealed shortening of the villi, diphtheritic pseudomembrane formation and the presence of C. perfringens organisms among the necrotic epithelium. It was concluded that intestinal damage characterised by destruction of crypts cells, as well as villi enterocytes and rupture of blood vessels by schizonts and merozoites of E. necatrix predisposed the chicken to a clinical form of NE to increase the mortality percentage.Pokusno istraživanje u tovnih pilića poduzeto je radi procjene predispozicijskog učinka kokcidioze na pojavu nekrotičnog enteritisa (NE). U prvom pokusu (samo NE), simptomi su bili uočeni od 4. do 7. dana nakon zaražavanja, ali bez uginuća. U drugom pokusu (NE uz prethodnu kokcidiozu) ustanovljen je 23%- tni mortalitet. Najjače patoanatomske promjene (2. stupnja) na crijevima bile su u prvom pokusu opažene 6. dana nakon infekcije. I u drugom pokusu najjače promjene na crijevima (3,67) bile su ustanovljene 6. dana nakon infekcije. U prvom je pokusu mikroskopski bila dokazana hiperplazija crijevnih resica u sluznici jejunuma i to od 4. do 7. dana nakon infekcije. U drugom je pokusu teška hiperplazija crijevnih resica bila dokazana od 2. do 4. dana nakon infekcije. Dokazani su bili i šizonti vrste E. necatrix u enterocitima i izvan njih. U drugom je pokusu bilo zapaženo i skraćenje crijevnih resica od 5. do 7. dana nakon infekcije, zatim difterične pseudomembranozne naslage te prisutnost bakterije C. perfringens u nekrotičnom epitelu. Zaključuje se da oštećenje crijeva uzrokovano šizontima i merozoitima vrste E. necatrix, koje se očitovalo propadanjem stanica crijevnih kripti kao i propadanjem crijevnih resica te prsnućem krvnih žila, djeluje kao predispozicijski čimbenik na kliničku pojavu nekrotičnog enteritisa i povećani mortaltet

Regulation of HAX-1 anti-apoptotic protein by Omi/HtrA2 protease during cell death

Omi/HtrA2 is a nuclear-encoded mitochondrial serine protease that has a pro-apoptotic function in mammalian cells. Upon induction of apoptosis, Omi translocates to the cytoplasm and participates in caspase-dependent apoptosis by binding and degrading inhibitor of apoptosis proteins. Omi can also initiate caspase-independent apoptosis in a process that relies entirely on its ability to function as an active protease. To investigate the mechanism of Omi-induced apoptosis, we set out to isolate novel substrates that are cleaved by this protease. We identified HS1-associated protein X-1 (HAX-1), a mitochondrial anti-apoptotic protein, as a specific Omi interactor that is cleaved by Omi both in vitro and in vivo. HAX-1 degradation follows Omi activation in cells treated with various apoptotic stimuli. Using a specific inhibitor of Omi, HAX-1 degradation is prevented and cell death is reduced. Cleavage of HAX-1 was not observed in a cell line derived from motor neuron degeneration 2 mice that carry a mutated form of Omi that affects its proteolytic activity. Degradation of HAX-1 is an early event in the apoptotic process and occurs while Omi is still confined in the mitochondria. Our results suggest that Omi has a unique pro-apoptotic function in mitochondria that involves removal of the HAX-1 antiapoptotic protein. This function is distinct from its ability to activate caspase-dependent apoptosis in the cytoplasm by degrading inhibitor of apoptosis proteins

Kongenitalni nefroblastom ploda holštajnsko-frizijske pasmine.

A seven-year-old Holstein-Friesian cow was brought to the hospital with signs of dystocia in the eighth month of gestation. The dystocia was relieved and a dead male fetus removed. The fetus had a significantly distended abdomen. At necropsy, the fetus showed a very large, round and well encapsulated extra renal mass in the abdominal cavity. The cut surfaces of the mass showed a white, caulifl ower-like growth with red surfaces. The lobules were spongy and distinctly demarcated by fat and hemorrhages. Microscopic examination of the tissue sections revealed blastemal, epithelial and mesenchymal elements. These cells were round to oval in shape with scanty cytoplasm. The nuclei were spherical, sometimes vesicular and hyperchromatic. The epithelial structures resembled the development of tubulo-glomerulogenesis. The mesenchymal cells were polyhedral in shape, found between the tubules. The gross and microscopic features of the tissue sections were consistent with a diagnosis of nephroblastoma.Krava holštajnsko-frizijske pasmine u dobi od sedam godina i osmom mjesecu steonosti dopremljena je na bolnički pregled sa znakovima distocije. Pri teškom teljenju uklonjen je uginuli muški plod. Plod je imao znatno povećan trbuh. Pri razudbi je ustanovljeno da je imao vrlo veliku, okruglu i dobro učahurenu tvorevinu oko bubrega u trbušnoj šupljini. Tvorevina je nalikovala na cvjetaču bjelkaste boje s crvenkastom površinom. Lobuli su bili spužvasti i jasno razgraničeni masnim tkivom s nalazom krvarenja. Mikroskopskom pretragom ustanovljene su primitivne epitelne i mezenhimne stanice. One su bile okrugle do jajolike s malo citoplazme. Jezgre su im bile okrugle, mjestimično mjehuričaste i hiperkromatske. Epitelna građa podsjećala je na tubuloglomerulogenezu. Mezenhimne stanice bile su višestraničnog oblika, smještene između tubula. Makroskopski i mikroskopski nalaz na prerezu tkiva ukazivao je na nefroblastom

Identification of FAM111A as an SV40 Host Range Restriction and Adenovirus Helper Factor

The small genome of polyomaviruses encodes a limited number of proteins that are highly dependent on interactions with host cell proteins for efficient viral replication. The SV40 large T antigen (LT) contains several discrete functional domains including the LXCXE or RB-binding motif, the DNA binding and helicase domains that contribute to the viral life cycle. In addition, the LT C-terminal region contains the host range and adenovirus helper functions required for lytic infection in certain restrictive cell types. To understand how LT affects the host cell to facilitate viral replication, we expressed full-length or functional domains of LT in cells, identified interacting host proteins and carried out expression profiling. LT perturbed the expression of p53 target genes and subsets of cell-cycle dependent genes regulated by the DREAM and the B-Myb-MuvB complexes. Affinity purification of LT followed by mass spectrometry revealed a specific interaction between the LT C-terminal region and FAM111A, a previously uncharacterized protein. Depletion of FAM111A recapitulated the effects of heterologous expression of the LT C-terminal region, including increased viral gene expression and lytic infection of SV40 host range mutants and adenovirus replication in restrictive cells. FAM111A functions as a host range restriction factor that is specifically targeted by SV40 LT

Hot-Carrier Cooling in High-Quality Graphene is Intrinsically Limited by Optical Phonons

Many promising optoelectronic devices, such as broadband photodetectors, nonlinear frequency converters, and building blocks for data communication systems, exploit photoexcited charge carriers in graphene. For these systems, it is essential to understand, and eventually control, the cooling dynamics of the photoinduced hot-carrier distribution. There is, however, still an active debate on the different mechanisms that contribute to hot-carrier cooling. In particular, the intrinsic cooling mechanism that ultimately limits the cooling dynamics remains an open question. Here, we address this question by studying two technologically relevant systems, consisting of high-quality graphene with a mobility >10,000 cm$^2$V$^{-1}$s$^{-1}$ and environments that do not efficiently take up electronic heat from graphene: WSe$_2$-encapsulated graphene and suspended graphene. We study the cooling dynamics of these two high-quality graphene systems using ultrafast pump-probe spectroscopy at room temperature. Cooling via disorder-assisted acoustic phonon scattering and out-of-plane heat transfer to the environment is relatively inefficient in these systems, predicting a cooling time of tens of picoseconds. However, we observe much faster cooling, on a timescale of a few picoseconds. We attribute this to an intrinsic cooling mechanism, where carriers in the hot-carrier distribution with enough kinetic energy emit optical phonons. During phonon emission, the electronic system continuously re-thermalizes, re-creating carriers with enough energy to emit optical phonons. We develop an analytical model that explains the observed dynamics, where cooling is eventually limited by optical-to-acoustic phonon coupling. These fundamental insights into the intrinsic cooling mechanism of hot carriers in graphene will play a key role in guiding the development of graphene-based optoelectronic devices

Establishment of an In Vitro Assay for Assessing the Effects of Drugs on the Liver Stages of Plasmodium vivax Malaria

Plasmodium vivax (Pv) is the second most important human malaria parasite. Recent data indicate that the impact of Pv malaria on the health and economies of the developing world has been dramatically underestimated. Pv has a unique feature in its life cycle. Uninucleate sporozoites (spz), after invasion of human hepatocytes, either proceed to develop into tens of thousands of merozoites within the infected hepatocytes or remain as dormant forms called hypnozoites, which cause relapses of malaria months to several years after the primary infection. Elimination of malaria caused by Pv will be facilitated by developing a safe, highly effective drug that eliminates Pv liver stages, including hypnozoites. Identification and development of such a drug would be facilitated by the development of a medium to high throughput assay for screening drugs against Pv liver stages. We undertook the present pilot study to (1) assess the feasibility of producing large quantities of purified, vialed, cryopreserved Pv sporozoites and (2) establish a system for culturing the liver stages of Pv in order to assess the effects of drugs on the liver stages of Pv. We used primaquine (PQ) to establish this assay model, because PQ is the only licensed drug known to clear all Pv hepatocyte stages, including hypnozoites, and the effect of PQ on Pv hepatocyte stage development in vitro has not previously been reported. We report that we have established the capacity to reproducibly infect hepatoma cells with purified, cyropreserved Pv spz from the same lot, quantitate the primary outcome variable of infected hepatoma cells and demonstrate the inhibitory activity of primaquine on the infected hepatoma cells. We have also identified small parasite forms that may be hypnozoites. These data provide the foundation for finalizing a medium throughput, high content assay to identify new drugs for the elimination of all Pv liver stages

The Biochemistry, Ultrastructure, and Subunit Assembly Mechanism of AMPA Receptors

The AMPA-type ionotropic glutamate receptors (AMPA-Rs) are tetrameric ligand-gated ion channels that play crucial roles in synaptic transmission and plasticity. Our knowledge about the ultrastructure and subunit assembly mechanisms of intact AMPA-Rs was very limited. However, the new studies using single particle EM and X-ray crystallography are revealing important insights. For example, the tetrameric crystal structure of the GluA2cryst construct provided the atomic view of the intact receptor. In addition, the single particle EM structures of the subunit assembly intermediates revealed the conformational requirement for the dimer-to-tetramer transition during the maturation of AMPA-Rs. These new data in the field provide new models and interpretations. In the brain, the native AMPA-R complexes contain auxiliary subunits that influence subunit assembly, gating, and trafficking of the AMPA-Rs. Understanding the mechanisms of the auxiliary subunits will become increasingly important to precisely describe the function of AMPA-Rs in the brain. The AMPA-R proteomics studies continuously reveal a previously unexpected degree of molecular heterogeneity of the complex. Because the AMPA-Rs are important drug targets for treating various neurological and psychiatric diseases, it is likely that these new native complexes will require detailed mechanistic analysis in the future. The current ultrastructural data on the receptors and the receptor-expressing stable cell lines that were developed during the course of these studies are useful resources for high throughput drug screening and further drug designing. Moreover, we are getting closer to understanding the precise mechanisms of AMPA-R-mediated synaptic plasticity