392 research outputs found
Progressive postnatal assembly of limbic-autonomic circuits revealed by central transneuronal transport of pseudorabies virus
The development of neuronal projections to a target and the establishment of synaptic connections with that target can be temporally distinct events, which typically are distinguished by functional assessments. We have applied a novel neuroanatomical approach to characterize the development of limbic forebrain synaptic inputs to autonomic neurons in neonatal rats. Transneuronal labeling of preautonomic forebrain neurons was achieved by inoculating the ventral stomach wall with pseudorabies virus (PRV) on postnatal day 1 (P1), P4, or P8. In each age group, PRV-positive neurons were present in autonomic and preautonomic regions of the spinal cord and brainstem 62-64 hr after inoculation. Transneuronal forebrain labeling in rats injected on P8 was similar to the transneuronal labeling reported previously in adult rats and included neurons in the medial and lateral hypothalamus, amygdala, bed nucleus of the stria terminalis, and visceral cortices. However, no cortex labeling and only modest amygdala and bed nucleus labeling were observed in rats injected with PRV on P4, and only medial hypothalamic labeling was observed in rats injected on P1. Additional tracing experiments involving central injections of PRV or cholera toxin β indicated that lateral hypothalamic and telencephalic regions projected to the medullary dorsal vagal complex several days before establishing synaptic connections with gastric-related autonomic neurons. These results demonstrate a novel strategy for evaluating synaptic connectivity in developing neural circuits and show a temporally segregated postnatal emergence of medial hypothalamic, lateral hypothalamic, and telencephalic synaptic inputs to central autonomic neurons
What The Oregon Health Study Can Tell Us About Expanding Medicaid
The recently enacted Patient Protection and Affordable Care Act includes a major expansion of Medicaid to low-income adults in 2014. This paper describes the Oregon Health Study, a randomized controlled trial that will be able to shed some light on the likely effects of such expansions. In 2008, Oregon randomly drew names from a waiting list for its previously closed public insurance program. Our analysis of enrollment into this program found that people who signed up for the waiting list and enrolled in the Oregon Medicaid program were likely to have worse health than those who did not. However, actual enrollment was fairly low, partly because many applicants did not meet eligibility standards.United States. Dept. of Health and Human Services. Office of the Assistant Secretary for Planning and EvaluationCalifornia HealthCare FoundationJohn D. and Catherine T. MacArthur FoundationNational Institute on AgingRobert Wood Johnson FoundationAlfred P. Sloan FoundationUnited States. Social Security Administratio
Methylobacterium, a major component of the culturable bacterial endophyte community of wild Brassica seed
BACKGROUND: Plants are commonly colonized by a wide diversity of microbial species and the relationships created can range from mutualistic through to parasitic. Microorganisms that typically form symptomless associations with internal plant tissues are termed endophytes. Endophytes associate with most plant species found in natural and managed ecosystems. They are extremely important plant partners that provide improved stress tolerance to the host compared with plants that lack this symbiosis. Plant domestication has reduced endophyte diversity and therefore the wild relatives of many crop species remain untapped reservoirs of beneficial microbes. Brassica species display immense diversity and consequently provide the greatest assortment of products used by humans from a single plant genus important for agriculture, horticulture, bioremediation, medicine, soil conditioners, composting crops, and in the production of edible and industrial oils. Many endophytes are horizontally transmitted, but some can colonize the plant's reproductive tissues, and this gives these symbionts an efficient mechanism of propagation via plant seed (termed vertical transmission).
METHODS: This study surveyed 83 wild and landrace Brassica accessions composed of 14 different species with a worldwide distribution for seed-originating bacterial endophytes. Seed was stringently disinfected, sown within sterile tissue culture pots within a sterile environment and incubated. After approximately 1-month, direct isolation techniques were used to recover bacterial endophytes from roots and shoots of symptomless plants. Bacteria were identified based on the PCR amplification of partial 16S rDNA gene sequences and annotated using the BLASTn program against the NCBI rRNA database. A diversity index was used as a quantitative measure to reflect how many different bacterial species there were in the seed-originating microbial community of the Brassica accessions sampled.
RESULTS: Bacterial endophytes were recovered from the majority of the Brassica accessions screened. 16S rDNA gene sequencing identified 19 different bacterial species belonging to three phyla, namely Actinobacteria, Firmicutes and Proteobacteria with the most frequently isolated species being Methylobacterium fujisawaense, Stenotrophomonas rhizophila and Pseudomonas lactis. Methylobacterium was the dominant genus composing 56% of the culturable isolated bacterial community and was common in 77% of accessions possessing culturable bacterial endophytes. Two selected isolates of Methylobacterium significantly promoted plant growth when inoculated into a cultivar of oilseed rape and inhibited the growth of the pathogen Leptosphaeria maculans in dual culture. This is the first report that investigates the seed-originating endophytic microorganisms of wild Brassica species and highlights the Brassica microbiome as a resource for plant growth promoting bacteria and biological control agents.fals
A Dual Infection Pseudorabies Virus Conditional Reporter Approach to Identify Projections to Collateralized Neurons in Complex Neural Circuits
Replication and transneuronal transport of pseudorabies virus (PRV) are widely used to define the organization of neural circuits in rodent brain. Here we report a dual infection approach that highlights connections to neurons that collateralize within complex networks. The method combines Cre recombinase (Cre) expression from a PRV recombinant (PRV-267) and Cre-dependent reporter gene expression from a second infecting strain of PRV (PRV-263). PRV-267 expresses both Cre and a monomeric red fluorescent protein (mRFP) fused to viral capsid protein VP26 (VP26-mRFP) that accumulates in infected cell nuclei. PRV-263 carries a Brainbow cassette and expresses a red (dTomato) reporter that fills the cytoplasm. However, in the presence of Cre, the dTomato gene is recombined from the cassette, eliminating expression of the red reporter and liberating expression of either yellow (EYFP) or cyan (mCerulean) cytoplasmic reporters. We conducted proof-of-principle experiments using a well-characterized model in which separate injection of recombinant viruses into the left and right kidneys produces infection of neurons in the renal preautonomic network. Neurons dedicated to one kidney expressed the unique reporters characteristic of PRV-263 (cytoplasmic dTomato) or PRV-267 (nuclear VP26-mRFP). Dual infected neurons expressed VP26-mRFP and the cyan or yellow cytoplasmic reporters activated by Cre-mediated recombination of the Brainbow cassette. Differential expression of cyan or yellow reporters in neurons lacking VP26-mRFP provided a unique marker of neurons synaptically connected to dual infected neurons, a synaptic relationship that cannot be distinguished using other dual infection tracing approaches. These data demonstrate Cre-enabled conditional reporter expression in polysynaptic circuits that permits the identification of collateralized neurons and their presynaptic partners
Development of Plant-Fungal Endophyte Associations to Suppress Phoma Stem Canker in Brassica
Endophytic microorganisms are found within the tissues of many plants species, with some conferring several benefits to the host plant including resistance to plant diseases. In this study, two putative endophytic fungi that were previously isolated from wild seeds of Brassica, identified as Beauveria bassiana and Pseudogymnoascus pannorum, were inoculated into cultivars of three Brassica species-Brassica napus, Br. rapa and Br. oleracea. Both fungal endophytes were reisolated from above- and below-ground tissues of inoculated plants at four different plant-growth stages, including cotyledon, one-leaf, two-leaf, and four-leaf stages. None of the plants colonised by these fungi exhibited any obvious disease symptoms, indicating the formation of novel mutualistic associations. These novel plant-endophyte associations formed between Brassica plants and Be. bassiana significantly inhibited phoma stem canker, a devastating disease of Brassica crops worldwide, caused by the fungal pathogen Leptosphaeria maculans. The novel association formed with P. pannorum significantly suppressed the amount of disease caused by L. maculans in one out of two experiments. Although biological control is not a new strategy, endophytic fungi with both antiinsect and antifungal activity are a highly conceivable, sustainable option to manage pests and diseases of economically important crops.fals
IRAIA: A Portal Technology with a Semantic Layer Coordinating Multimedia Retrieval and Cross-Owner Content Building
A Herpesvirus Encoded Deubiquitinase Is a Novel Neuroinvasive Determinant
The neuroinvasive property of several alpha-herpesviruses underlies an uncommon infectious process that includes the establishment of life-long latent infections in sensory neurons of the peripheral nervous system. Several herpesvirus proteins are required for replication and dissemination within the nervous system, indicating that exploiting the nervous system as a niche for productive infection requires a specialized set of functions encoded by the virus. Whether initial entry into the nervous system from peripheral tissues also requires specialized viral functions is not known. Here we show that a conserved deubiquitinase domain embedded within a pseudorabies virus structural protein, pUL36, is essential for initial neural invasion, but is subsequently dispensable for transmission within and between neurons of the mammalian nervous system. These findings indicate that the deubiquitinase contributes to neurovirulence by participating in a previously unrecognized initial step in neuroinvasion
Equine post-breeding endometritis: A review
The deposition of semen, bacteria and debris in the uterus of the mare after breeding normally induces a self-limiting endometritis. The resultant fluid and inflammatory products are cleared by 48 hours post cover. Mares that are susceptible to persistent post-breeding endometritis (PPBEM) have impaired uterine defence and clearance mechanisms, making them unable to resolve this inflammation within the normal time. This persists beyond 48 hours post-breeding and causes persistent fluid accumulation within the uterus. Mares with PPBEM have an increased rate of embryonic loss and a lower overall pregnancy rate than those without the condition. To enhance conception rates, mares at high risk need optimal breeding management as well as early diagnosis, followed by the most appropriate treatment. This article reviews the pathogenesis, diagnosis and treatment of PPBEM and the management of affected mares
Population-Based Surveillance for Invasive Pneumococcal Disease in Homeless Adults in Toronto
BACKGROUND: Identification of high-risk populations for serious infection due to S. pneumoniae will permit appropriately targeted prevention programs. METHODS: We conducted prospective, population-based surveillance for invasive pneumococcal disease and laboratory confirmed pneumococcal pneumonia in homeless adults in Toronto, a Canadian city with a total population of 2.5 M, from January 1, 2002 to December 31, 2006. RESULTS: We identified 69 cases of invasive pneumococcal disease and 27 cases of laboratory confirmed pneumococcal pneumonia in an estimated population of 5050 homeless adults. The incidence of invasive pneumococcal disease in homeless adults was 273 infections per 100,000 persons per year, compared to 9 per 100,000 persons per year in the general adult population. Homeless persons with invasive pneumococcal disease were younger than other adults (median age 46 years vs 67 years, P<.001), and more likely than other adults to be smokers (95% vs. 31%, P<.001), to abuse alcohol (62% vs 15%, P<.001), and to use intravenous drugs (42% vs 4%, P<.001). Relative to age matched controls, they were more likely to have underlying lung disease (12/69, 17% vs 17/272, 6%, P = .006), but not more likely to be HIV infected (17/69, 25% vs 58/282, 21%, P = .73). The proportion of patients with recurrent disease was five fold higher for homeless than other adults (7/58, 12% vs. 24/943, 2.5%, P<.001). In homeless adults, 28 (32%) of pneumococcal isolates were of serotypes included in the 7-valent conjugate vaccine, 42 (48%) of serotypes included in the 13-valent conjugate vaccine, and 72 (83%) of serotypes included in the 23-valent polysaccharide vaccine. Although no outbreaks of disease were identified in shelters, there was evidence of clustering of serotypes suggestive of transmission of pathogenic strains within the homeless population. CONCLUSIONS: Homeless persons are at high risk of serious pneumococcal infection. Vaccination, physical structure changes or other program to reduce transmission in shelters, harm reduction programs to reduce rates of smoking, alcohol abuse and infection with bloodborne pathogens, and improved treatment programs for HIV infection may all be effective in reducing the risk
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