445 research outputs found

    Sex differences in the influence of social context, salient social stimulation and amphetamine on ultrasonic vocalizations in prairie voles

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    Prairie voles ( Microtus ochrogaster ) are a socially monogamous rodent species and their cooperative behaviors require extensive communication between conspecifics. Rodents use ultrasonic vocalizations (USVs) to communicate and because a prairie vole breeder pair must engage in extensive cooperation for successful reproduction, auditory communication may be critical for this species. Therefore, we sought to characterize USVs in adult male and female prairie voles, and to determine how these calls are influenced by social context, salient social stimuli and the psychostimulant drug of abuse amphetamine (AMPH). Here, we characterize prairie vole USVs by showing the range of frequencies of prairie vole USVs, the proportion of various call types, how these call types compare between males and females, and how they are influenced by social stimulation and AMPH. AMPH caused a robust increase in the number of USVs in both males and females and there was a dramatic sex difference in the complexity of call structures of AMPH‐induced USVs, with males emitting more elaborate calls. Moreover, we show that novel (i.e. salient) social cues evoked differential increases in USVs across sex, with males showing a much more robust increase in USV production, both with respect to the frequency and complexity of USV production. Exposure to an estrous female in particular caused an extraordinary increase in USVs in male subjects. These data suggest that USVs may be a useful measure of social motivation in this species, including how social behaviors can be impacted by drugs of abuse.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/107527/1/inz212071.pd

    Sub-clinical effects of chronic noise exposure on vestibular system

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    Aim: to investigate the effect of chronic noise exposure on vestibular function of subjects without clinical evidence of vestibular disorders and with documented cochlear damage from noise. Subjects and methods: 25 patients with chronic noise- induced hearing loss (NIHL) and without vestibular complaints (group A) and 25 matched controls with sensorineural hearing loss without noise exposure (group B), underwent audiological and vestibular test including caloric and cervical vestibular-evoked myogenic potentials tests (cVEMPs). Results: In subjects chronically exposed to noise, similarly to that of the auditory threshold, an increase in the evocation threshold of VEMPs has been documented, statistically significant (p<0,05) and independent of the performance of the auditory threshold. p1-n1 amplitude values showed a significant difference between group A and group B. No significant difference for p1-n1 latencies between the two groups was found. Conclusion: We have documented the possibility of vestibular lesion, along with cochlear damage, related to chronic acoustic trauma

    Tinnitus and equilibrium disorders in COVID-19 patients: preliminary results

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    Purpose: Tinnitus and equilibrium disorders such as dizziness and vertigo have been reported by patients with COVID-19; however, they have been rarely investigated. The aim of this study was to study the prevalence of subjective tinnitus and dizziness in a sample of COVID-19 patients using an online 10-item close-ended questionnaire. Methods: A multicentric study that included 15 Italian hospitals in different regions was conducted using an online 10-item close-ended questionnaire developed to identify the presence of tinnitus and balance disorders in patients with COVID-19 between May 5 and June 10, 2020. The questionnaire was administered to 185 patients in a period of > 30 – < 60 days after diagnosis of COVID-19; responses were recorded in an online Excel spreadsheet. The questionnaire was composed of three sections: (1) demographic information; (2) presence and characteristics of tinnitus and dizziness after COVID-19 diagnosis; (3) possible association with migraine. Results: Thirty-four patients (18.4%) reported equilibrium disorders after COVID-19 diagnosis. Of these, 32 patients reported dizziness (94.1%) and 2 (5.9%) reported acute vertigo attacks. Forty-three patients (23.2%) reported tinnitus; 14 (7.6%) reported both tinnitus and equilibrium disorders. Conclusion: This study suggests that the presence of subjective otoneurological symptoms such as tinnitus and balance disorders can affect COVID-19 patients; further studies are necessary to investigate the prevalence and pathophysiological mechanisms underlying these subjective symptoms in COVID-19 patients

    Sudden olfactory loss as an early marker of COVID-19: a nationwide Italian survey

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    Purpose: The presence of many asymptomatic COVID-19 cases may increase the risks of disease dissemination, mainly for physicians. There are numerous reports on the frequent findings of sudden anosmia or hyposmia, before or at the same time of the typical COVID-19 symptoms onset. The aim of this study was to verify the association of olfactory impairment and COVID-19, providing a basis for subsequent research in the field of COVID-19 clinical heterogeneity. Methods: We developed a 15-item online questionnaire on “Sudden Olfactory Loss (SOL) and COVID-19” that was administered during March 2020 to Italian general practitioners registered to a social media group. Results: One hundred and eighty responses were received. SOL was identified as a significant sign of infection in COVID-19 patients, mainly aged between 30 and 40 years, even in the absence of other symptoms. SOL was present as an initial symptom in 46.7% of subjects, and in 16.7%, it was the only symptom. Among the COVID-19 confirmed cases, SOL occurred as the only symptom in 19.2% of patients. Conclusion: SOL could represent a possible early symptom in otherwise asymptomatic COVID-19 subjects. Subjects affected by SOL should be considered as potential COVID-19 cases. Level of evidence: 4

    Fermi LAT Observations of LS I +61 303: First detection of an orbital modulation in GeV Gamma Rays

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    This Letter presents the first results from the observations of LSI +61 303 using Large Area Telescope data from the Fermi Gamma-Ray Space Telescope between 2008 August and 2009 March. Our results indicate variability that is consistent with the binary period, with the emission being modulated at 26.6 +/- 0.5 days. This constitutes the first detection of orbital periodicity in high-energy gamma rays (20 MeV-100 GeV, HE). The light curve is characterized by a broad peak after periastron, as well as a smaller peak just before apastron. The spectrum is best represented by a power law with an exponential cutoff, yielding an overall flux above 100 MeV of 0.82 +/- 0.03(stat) +/- 0.07(syst) 10^{-6} ph cm^{-2} s^{-1}, with a cutoff at 6.3 +/- 1.1(stat) +/- 0.4(syst) GeV and photon index Gamma = 2.21 +/- 0.04(stat) +/- 0.06(syst). There is no significant spectral change with orbital phase. The phase of maximum emission, close to periastron, hints at inverse Compton scattering as the main radiation mechanism. However, previous very high-energy gamma ray (>100 GeV, VHE) observations by MAGIC and VERITAS show peak emission close to apastron. This and the energy cutoff seen with Fermi suggest the link between HE and VHE gamma rays is nontrivial.Comment: 7 pages, 5 figures, accepted for publication in ApJ Letters 21 July 200

    Mechanisms of stretch-mediated skin expansion at single-cell resolution.

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    The ability of the skin to grow in response to stretching has been exploited in reconstructive surgery1. Although the response of epidermal cells to stretching has been studied in vitro2,3, it remains unclear how mechanical forces affect their behaviour in vivo. Here we develop a mouse model in which the consequences of stretching on skin epidermis can be studied at single-cell resolution. Using a multidisciplinary approach that combines clonal analysis with quantitative modelling and single-cell RNA sequencing, we show that stretching induces skin expansion by creating a transient bias in the renewal activity of epidermal stem cells, while a second subpopulation of basal progenitors remains committed to differentiation. Transcriptional and chromatin profiling identifies how cell states and gene-regulatory networks are modulated by stretching. Using pharmacological inhibitors and mouse mutants, we define the step-by-step mechanisms that control stretch-mediated tissue expansion at single-cell resolution in vivo.Wellcome Trust Royal Societ

    Long-term cultivation of colorectal carcinoma cells with anti-cancer drugs induces drug resistance and telomere elongation: an in vitro study

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    BACKGROUND: The role of telomerase activation in the expression and/or maintenance of drug resistance is not clearly understood. Therefore, we investigated the relationships, among the telomerase activity, telomere length and the expression of multidrug resistance genes in colorectal cancer cell lines cultivated with anti-cancer drugs. METHODS: LoVo and DLD-1 cells were continuously grown in the presence of both CDDP and 5-FU for up to 100 days. Cell proliferation, telomerase activity, telomere length and the expression of multidrug resistance genes were serially monitored as the PDL increased. RESULTS: The expression of multidrug resistance genes tended to increase as the PDL increased. However, an abnormal aneuploid clone was not detected as far as the cells were monitored by a DNA histogram analysis. Tumor cells showing resistance to anti-cancer drugs revealed a higher cell proliferation rate. The telomere length gradually increased with a progressive PDL. The telomerase activity reached a maximum level at 15 PDL in LoVo cells and at 27 PDL in DLD-1 cells. An increase in the mRNA expression of the telomerase components, especially in hTERT and in hTR, was observed at the same PDLs. CONCLUSIONS: These results suggest that a high telomerase activity and an elongation of telomeres both appear to help maintain and/or increase drug resistance in colorectal cancer cells. Cancer cells with long telomeres and a high proliferative activity may thus be able to better survive exposure to anti-cancer drugs. This is presumably due to an increased chromosome stability and a strong expression of both mdr-1 and MRP genes
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