524 research outputs found

    Acute Suppressive and Long-Term Phase Modulation Actions of Orexin on the Mammalian Circadian Clock

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    Circadian and homeostatic neural circuits organize the temporal architecture of physiology and behavior, but knowledge of their interactions is imperfect. For example, neurons containing the neuropeptide orexin homeostatically control arousal and appetitive states, while neurons in the suprachiasmatic nuclei (SCN) function as the brain's master circadian clock. The SCN regulates orexin neurons so that they are much more active during the circadian night than the circadian day, but it is unclear whether the orexin neurons reciprocally regulate the SCN clock. Here we show both orexinergic innervation and expression of genes encoding orexin receptors (OX1 and OX2) in the mouse SCN, with OX1 being upregulated at dusk. Remarkably, we find through in vitro physiological recordings that orexin predominantly suppresses mouse SCN Period1 (Per1)-EGFP-expressing clock cells. The mechanisms underpinning these suppressions vary across the circadian cycle, from presynaptic modulation of inhibitory GABAergic signaling during the day to directly activating leak K+ currents at night. Orexin also augments the SCN clock-resetting effects of neuropeptide Y (NPY), another neurochemical correlate of arousal, and potentiates NPY's inhibition of SCN Per1-EGFP cells. These results build on emerging literature that challenge the widely held view that orexin signaling is exclusively excitatory and suggest new mechanisms for avoiding conflicts between circadian clock signals and homeostatic cues in the brain

    Surveying uveitis specialistsā€”a call for consensus

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    Thomas Brennan became disillusioned with popular law school rankings and so decided to survey 100 academics, judges, and lawyers on his own, asking them to rank a list of ten schools he provided. He used a composite index similar in structure, but different in content, to those used by main-stream surveyors, such as U.S. News & World Report. As expected, many of the big name schoolsā€”Harvard, Yale, Stanfordā€”made it to the top of the list. Penn State, as Brennan recalled, ā€œ[Was] about in the middle of the pack. Maybe fifth among the 10 schools listed. ā€ There was one small problem, however. Penn State had no law school at the time. Brennan had included it to make a point: surveys are limited by both the quality of the questions asked and by how familiar respondents are with the subject being surveyed [1, 2]

    Cardiac afferent activity modulates the expression of racial stereotypes

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    Negative racial stereotypes tend to associate Black people with threat. This often leads to the misidentification of harmless objects as weapons held by a Black individual. Yet, little is known about how bodily states impact the expression of racial stereotyping. By tapping into the phasic activation of arterial baroreceptors, known to be associated with changes in the neural processing of fearful stimuli, we show activation of race-threat stereotypes synchronized with the cardiovascular cycle. Across two established tasks, stimuli depicting Black or White individuals were presented to coincide with either the cardiac systole or diastole. Results show increased race-driven misidentification of weapons during systole, when baroreceptor afferent firing is maximal, relative to diastole. Importantly, a third study examining the positive Black-athletic stereotypical association fails to demonstrate similar modulations by cardiac cycle. We identify a bodyā€“brain interaction wherein interoceptive cues can modulate threat appraisal and racially biased behaviour in context-dependent ways

    Efficacy and Safety of a New 20% Immunoglobulin Preparation for Subcutaneous Administration, IgPro20, in Patients With Primary Immunodeficiency

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    Subcutaneous human IgG (SCIG) therapy in primary immunodeficiency (PID) offers sustained IgG levels throughout the dosing cycle and fewer adverse events (AEs) compared to intravenous immunoglobulin (IVIG). A phase I study showed good local tolerability of IgPro20, a new 20% liquid SCIG stabilized with L-proline. A prospective, open-label, multicenter, single-arm, phase III study evaluated the efficacy and safety of IgPro20 in patients with PID over 15Ā months. Forty-nine patients (5ā€“72Ā years) previously treated with IVIG received weekly subcutaneous infusions of IgPro20. The mean serum IgG level was 12.5Ā g/L. No serious bacterial infections were reported. There were 96 nonserious infections (rate 2.76/patient per year). The rate of days missed from work/school was 2.06/patient per year, and the rate of hospitalization was 0.2/patient per year. Ninety-nine percent of AEs were mild or moderate. No serious, IgPro20-related AEs were reported. IgPro20 effectively protected patients with PID against infections and maintained serum IgG levels without causing unexpected AEs

    SR4GN: A Species Recognition Software Tool for Gene Normalization

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    As suggested in recent studies, species recognition and disambiguation is one of the most critical and challenging steps in many downstream text-mining applications such as the gene normalization task and protein-protein interaction extraction. We report SR4GN: an open source tool for species recognition and disambiguation in biomedical text. In addition to the species detection function in existing tools, SR4GN is optimized for the Gene Normalization task. As such it is developed to link detected species with corresponding gene mentions in a document. SR4GN achieves 85.42% in accuracy and compares favorably to the other state-of-the-art techniques in benchmark experiments. Finally, SR4GN is implemented as a standalone software tool, thus making it convenient and robust for use in many text-mining applications. SR4GN can be downloaded at: http://www.ncbi.nlm.nih.gov/CBBresearch/Lu/downloads/SR4G

    Respiratory syncytial virus infection is associated with an altered innate immunity and a heightened pro-inflammatory response in the lungs of preterm lambs

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    <p>Abstract</p> <p>Introduction</p> <p>Factors explaining the greater susceptibility of preterm infants to severe lower respiratory infections with respiratory syncytial virus (RSV) remain poorly understood. Fetal/newborn lambs are increasingly appreciated as a model to study key elements of RSV infection in newborn infants due to similarities in lung alveolar development, immune response, and susceptibility to RSV. Previously, our laboratory demonstrated that preterm lambs had elevated viral antigen and developed more severe lesions compared to full-term lambs at seven days post-infection. Here, we compared the pathogenesis and immunological response to RSV infection in lungs of preterm and full-term lambs.</p> <p>Methods</p> <p>Lambs were delivered preterm by Caesarian section or full-term by natural birth, then inoculated with bovine RSV (bRSV) via the intratracheal route. Seven days post-infection, lungs were collected for evaluation of cytokine production, histopathology and cellular infiltration.</p> <p>Results</p> <p>Compared to full-term lambs, lungs of preterm lambs had a heightened pro-inflammatory response after infection, with significantly increased MCP-1, MIP-1Ī±, IFN-Ī³, TNF-Ī± and PD-L1 mRNA. RSV infection in the preterm lung was characterized by increased epithelial thickening and periodic acid-Schiff staining, indicative of glycogen retention. Nitric oxide levels were decreased in lungs of infected preterm lambs compared to full-term lambs, indicating alternative macrophage activation. Although infection induced significant neutrophil recruitment into the lungs of preterm lambs, neutrophils produced less myeloperoxidase than those of full-term lambs, suggesting decreased functional activation.</p> <p>Conclusions</p> <p>Taken together, our data suggest that increased RSV load and inadequate immune response may contribute to the enhanced disease severity observed in the lungs of preterm lambs.</p

    Complications and reoperations of the SB CharitƩ lumbar disc prosthesis: experience in 75 patients

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    Artificial disc prosthesis show fair to good short- and mid-term results. Long-term results are becoming apparent now, however, the incidence of late complications with this procedure remain poorly understood. In this report we will analyse late complications and discuss our experiences with salvage operations in patients with persistent pain after SB CharitĆ© disc prosthesis implantation. Seventy-five patients with persistent leg and back pain after insertion of an artificial disc prosthesis were enrolled in the study. In this negative selection frequently occurring late-complications were subsidence, wear, adjacent disc degeneration, facet joint degeneration and migration. In 15 patients we performed a posterior fusion without disc removal, and in 22 patients we removed 26 prostheses and performed a posterior and anterior fusion. The visual analogue scale (VAS) and Oswestry were examined before the salvage operation and after a follow-up period of at least 1Ā year, which is not yet available in all patients. The VAS and Oswestry decreased in the posterior group (nĀ =Ā 10) respectively from 8.0 (SD 0.9) to 6.3 (SD 2.1) and from 57.0 (SD 17.0) to 44.6 (SD 20.4); and in the disc removal group (nĀ =Ā 14) respectively from 8.0 (SD 0.9) to 5.6 (SD 2.7) and from 56.3 (SD 14.0) to 43.0 (SD 20.7). Serious late complications may occur following total disc replacement. Removal of the SB CharitĆ© artificial disc is feasible but with inherent risks. Removal of the disc prosthesis gives slightly better results than posterior fusion alone after a follow-up of at least 1Ā year

    Evaluation of the antibacterial and anticancer activities of some South African medicinal plants

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    <p>Abstract</p> <p>Background</p> <p>Several herbs are traditionally used in the treatment of a variety of ailments particularly in the rural areas of South Africa where herbal medicine is mainly the source of health care system. Many of these herbs have not been assessed for safety or toxicity to tissue or organs of the mammalian recipients.</p> <p>Methods</p> <p>This study evaluated the cytotoxicity of some medicinal plants used, inter alia, in the treatment of diarrhoea, and stomach disorders. Six selected medicinal plants were assessed for their antibacterial activities against ampicillin-resistant and kanamycin-resistant strains of <it>Escherichia coli </it>by the broth micro-dilution methods. The cytotoxicities of methanol extracts and fractions of the six selected plants were determined using a modified tetrazolium-based colorimetric assay (3-(4, 5-dimethylthiazol)-2, 5-diphenyl tetrazolium bromide (MTT) assay).</p> <p>Results</p> <p>The average minimum inhibitory concentration (MIC) values of the plants extracts ranged from 0.027 mg/mā„“ to 2.5 mg/mā„“ after 24 h of incubation. <it>Eucomis autumnalis </it>and <it>Cyathula uncinulata </it>had the most significant biological activity with the least MIC values. The in vitro cytotoxicity assay on human hepatocarcinoma cell line (Huh-7) revealed that the methanol extract of <it>E. autumnalis </it>had the strongest cytotoxicity with IC<sub>50 </sub>of 7.8 Ī¼g/mā„“. Ethyl acetate and butanol fractions of <it>C. uncinulata, Hypoxis latifolia, E. autumnalis </it>and <it>Lantana camara </it>had lower cytotoxic effects on the cancer cell lines tested with IC<sub>50 </sub>values ranging from 24.8 to 44.1 Ī¼g/mā„“; while all the fractions of <it>Aloe arborescens </it>and <it>A. striatula </it>had insignificant or no cytotoxic effects after 72 h of treatment.</p> <p>Conclusions</p> <p>Our results indicate that the methanol fraction of <it>E. autumnalis </it>had a profound cytotoxic effect even though it possessed very significant antibacterial activity. This puts a query on its safety and hence a call for caution in its usage, thus a product being natural is not tantamount to being entirely safe. However, the antibacterial activities and non-cytotoxic effects of <it>A. arborescens </it>and <it>A. striatula </it>validates their continuous usage in ethnomedicine.</p

    Menstrual Cycle and Facial Preferences Reconsidered

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    Two previous articles reported that women prefer less feminized male faces during the fertile phase of their menstrual cycle, supposedly reflecting an evolved mating strategy whereby women choose mates of maximum genetic quality when conception is likely. The current article contends this theory rests on several questionable assumptions about human ancestral mating systems. A new empirical test also was conducted: 853 adults, primarily from North America, evaluated facial attractiveness of photos. The study included more complete evaluation of ovulatory status and a greater number (nā€‰=ā€‰258) of target women than past research. The results did not suggest any greater preference for masculine faces when fertilization was likely. The article concludes with general comments about evolutionary theorizing and interpersonal relationships
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