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BACKGROUND: The members of the genus Muntiacus are of particular interest to evolutionary biologists due to their extreme chromosomal rearrangements and the ongoing discussions about the number of living species. Red muntjacs have the largest distribution of all muntjacs and were formerly considered as one species. Karyotype differences led to the provisional split between the Southern Red Muntjac (Muntiacus muntjak) and the Northern Red Muntjac (M. vaginalis), but uncertainties remain as, so far, no phylogenetic study has been conducted. Here, we analysed whole mitochondrial genomes of 59 archival and 16 contemporaneous samples to resolve uncertainties about their taxonomy and used red muntjacs as model for understanding the evolutionary history of other species in Southeast Asia. RESULTS: We found three distinct matrilineal groups of red muntjacs: Sri Lankan red muntjacs (including the Western Ghats) diverged first from other muntjacs about 1.5 Mya; later northern red muntjacs (including North India and Indochina) and southern red muntjacs (Sundaland) split around 1.12 Mya. The diversification of red muntjacs into these three main lineages was likely promoted by two Pleistocene barriers: one through the Indian subcontinent and one separating the Indochinese and Sundaic red muntjacs. Interestingly, we found a high level of gene flow within the populations of northern and southern red muntjacs, indicating gene flow between populations in Indochina and dispersal of red muntjacs over the exposed Sunda Shelf during the Last Glacial Maximum. CONCLUSIONS: Our results provide new insights into the evolution of species in South and Southeast Asia as we found clear genetic differentiation in a widespread and generalist species, corresponding to two known biogeographical barriers: The Isthmus of Kra and the central Indian dry zone. In addition, our molecular data support either the delineation of three monotypic species or three subspecies, but more importantly these data highlight the conservation importance of the Sri Lankan/South Indian red muntjac.
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Mitocôndrias/genética , Cervo Muntjac/classificação , Animais , Sudeste Asiático , DNA Mitocondrial , Evolução Molecular , Índia , Cariotipagem , Tipagem Molecular , Cervo Muntjac/genética , Filogenia , FilogeografiaRESUMO
Chronic medical conditions (i.e., chronic widespread pain) may contribute to accelerated/accentuated aging, such that middle-aged individuals with comorbidities may actually show increased declines in physical, cognitive, and mental health compared to normal aging adults. We examined perceived stress, life stressors, and depression in adults with and without fibromyalgia, a chronic pain condition. Ninety-four participants (52% with fibromyalgia, 78% female) aged 50 to 93 were administered the Perceived Stress Scale, Social Readjustment Rating Scale, and Beck Depression Inventory. Hierarchical regression analyses were conducted: the predictor variables were age, gender, fibromyalgia status, depression, and fibromyalgia-depression interaction. The interaction term significantly predicted perceived stress, but not life stressors. Depression significantly predicted stress for Social Readjustment Rating Scale measures after controlling for covariates. Significant associations were found between perceived stress and life stressors in all participants. In addition, those with fibromyalgia were significantly more likely to report higher levels of stress above standardized scores on both the Perceived Stress Scale and the Social Readjustment Rating Scale. Finally, depressive symptoms played a more significant role than fibromyalgia status in predicting life stressors. Conclusions: These findings emphasize the importance of assessing different types of stress and stressors in individuals with chronic widespread pain and/or depression in mid-life and beyond to better treat individuals with these conditions.
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Taste loss in human patients following radiotherapy for head and neck cancer is a common and significant problem, but the cellular mechanisms underlying this loss are not understood. Taste stimuli are transduced by receptor cells within taste buds, and like epidermal cells, taste cells are regularly replaced throughout adult life. This renewal relies on progenitor cells adjacent to taste buds, which continually supply new cells to each bud. Here we treated adult mice with a single 8 Gy dose of x-ray irradiation to the head and neck, and analyzed taste epithelium at 1-21 d postirradiation (dpi). We found irradiation targets the taste progenitor cells, which undergo cell cycle arrest (1-3 dpi) and apoptosis (within 1 dpi). Taste progenitors resume proliferation at 5-7 dpi, with the proportion of cells in S and M phase exceeding control levels at 5-6 and 6 dpi, respectively, suggesting that proliferation is accelerated and/or synchronized following radiation damage. Using 5-bromo-2-deoxyuridine birthdating to identify newborn cells, we found that the decreased proliferation following irradiation reduces the influx of cells at 1-2 dpi, while the robust proliferation detected at 6 dpi accelerates entry of new cells into taste buds. In contrast, the number of differentiated taste cells was not significantly reduced until 7 dpi. These data suggest a model where continued natural taste cell death, paired with temporary interruption of cell replacement, underlies taste loss after irradiation.
Assuntos
Cabeça/efeitos da radiação , Pescoço/efeitos da radiação , Células-Tronco Neurais/patologia , Células-Tronco Neurais/efeitos da radiação , Papilas Gustativas/patologia , Papilas Gustativas/efeitos da radiação , Animais , Morte Celular/fisiologia , Diferenciação Celular/efeitos da radiação , Relação Dose-Resposta à Radiação , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Objective: Examine the psychosocial adjustment of U.S. college and university students during the early months of the COVID-19 pandemic. Participants: Higher education students in the U.S. (N = 228), recruited between March 2020 and May 2020. Methods: Participants completed self-report measures regarding their psychosocial functioning online. Qualitative and quantitative methods were used to explore participants' psychosocial adjustment. Results: Participants reported increased concerns about such stressors as academics, job loss, health, and social isolation. They reported significantly elevated symptoms of depression, anxiety, perceived stress, and somatization, and prior history of psychological counseling was associated with greater levels of distress. Approximately one-third of participants reported inadequate perceived social support, which in turn was linked to psychosocial adjustment. Conclusions: College students reported experiencing a wide range of stressors related to the pandemic. Increasing access to mental health services and providing supportive services in such areas as social connection and employment are encouraged.
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COVID-19 , Humanos , COVID-19/epidemiologia , Pandemias , Estudantes , Universidades , Ansiedade/epidemiologiaRESUMO
BACKGROUND: Bone Morphogenetic Protein 4 (BMP4) is a diffusible factor which regulates embryonic taste organ development. However, the role of BMP4 in taste buds of adult mice is unknown. We utilized transgenic mice with LacZ under the control of the BMP4 promoter to reveal the expression of BMP4 in the tongues of adult mice. Further we evaluate the pattern of BMP4 expression with that of markers of specific taste bud cell types and cell proliferation to define and compare the cell populations expressing BMP4 in anterior (fungiform papillae) and posterior (circumvallate papilla) tongue. RESULTS: BMP4 is expressed in adult fungiform and circumvallate papillae, i.e., lingual structures composed of non-taste epithelium and taste buds. Unexpectedly, we find both differences and similarities with respect to expression of BMP4-driven ß-galactosidase. In circumvallate papillae, many fusiform cells within taste buds are BMP4-ß-gal positive. Further, a low percentage of BMP4-expressing cells within circumvallate taste buds is immunopositive for markers of each of the three differentiated taste cell types (I, II and III). BMP4-positive intragemmal cells also expressed a putative marker of immature taste cells, Sox2, and consistent with this finding, intragemmal cells expressed BMP4-ß-gal within 24 hours after their final mitosis, as determined by BrdU birthdating. By contrast, in fungiform papillae, BMP4-ß-gal positive cells are never encountered within taste buds. However, in both circumvallate and fungiform papillae, BMP4-ß-gal expressing cells are located in the perigemmal region, comprising basal and edge epithelial cells adjacent to taste buds proper. This region houses the proliferative cell population that gives rise to adult taste cells. However, perigemmal BMP4-ß-gal cells appear mitotically silent in both fungiform and circumvallate taste papillae, as we do not find evidence of their active proliferation using cell cycle immunomarkers and BrdU birthdating. CONCLUSION: Our data suggest that intragemmal BMP4-ß-gal cells in circumvallate papillae are immature taste cells which eventually differentiate into each of the 3 taste cell types, whereas perigemmal BMP4-ß-gal cells in both circumvallate and fungiform papillae may be slow cycling stem cells, or belong to the stem cell niche to regulate taste cell renewal from the proliferative cell population.
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Proteína Morfogenética Óssea 4/biossíntese , Papilas Gustativas/metabolismo , Alelos , Animais , Antimetabólitos , Proteína Morfogenética Óssea 4/genética , Bromodesoxiuridina , Ciclo Celular/fisiologia , Diferenciação Celular/fisiologia , Proliferação de Células , Células Epiteliais/fisiologia , Imunofluorescência , Genes Reporter , Óperon Lac , Camundongos , Camundongos Transgênicos , Fatores de Transcrição SOXB1/biossíntese , Papilas Gustativas/citologiaRESUMO
Mitochondrial genomes of five Laotian Rock Rat (Laonastes aenigmamus) samples from Vietnam and Laos were sequenced using an Illumina platform. After de novo assembly, 13 protein-coding genes and two rRNA (12S and 16S) of the five genomes were aligned and analyzed with those from other related species under maximum likelihood and Bayesian inferences. Both methods revealed congruent tree topologies, which support two independently evolving clades of L. aenigmamus from Laos and Vietnam. The relaxed time calibration analysis showed that the two major lineages of the Laotian Rock Rat split about 8 million years ago, which was consistent with the results from previous studies using only cytochrome b sequences. Such a deep divergence time suggests the recognition of two rock rat species, but further nuclear DNA and morphological data are needed to solve the taxonomy of this taxon.
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OBJECTIVES: To determine prospectively the causative pathogens of central nervous system (CNS) infections in patients admitted to a tertiary referral hospital in Hanoi, Vietnam. METHODS: From May 2007 to December 2008, cerebrospinal fluid (CSF) samples from 352 adults with suspected meningitis or encephalitis underwent routine testing, staining (Gram, Ziehl-Nielsen, India ink), bacterial culture and polymerase chain reaction targeting Neisseria meningitidis, Streptococcus pneumoniae, S. suis, Haemophilus influenzae type b, Herpes simplex virus (HSV), Varicella Zoster virus (VZV), enterovirus, and 16S ribosomal RNA. Blood cultures and clinically indicated radiology were also performed. Patients were classified as having confirmed or suspected bacterial (BM), tuberculous (TBM), cryptococcal (CRM), eosinophilic (EOM) meningitis, aseptic encephalitis/meningitis (AEM), neurocysticercosis and others. RESULTS: 352 (male: 66%) patients were recruited: median age 34 years (range 13-85). 95/352 (27.3%) diagnoses were laboratory confirmed and one by cranial radiology: BM (nâ=â62), TBM (nâ=â9), AEM (nâ=â19), CRM (nâ=â5), and neurocysticercosis (nâ=â1, cranial radiology). S. suis predominated as the cause of BM [48/62 (77.4%)]; Listeria monocytogenese (nâ=â1), S. pasteurianus (nâ=â1) and N. meningitidis (nâ=â2) were infrequent. AEM viruses were: HSV (nâ=â12), VZV (nâ=â5) and enterovirus (nâ=â2). 5 patients had EOM. Of 262/352 (74.4%) patients with full clinical data, 209 (79.8%) were hospital referrals and 186 (71%) had been on antimicrobials. 21 (8%) patients died: TBM (15.2%), AEM (10%), and BM (2.8%). CONCLUSIONS: Most infections lacked microbiological confirmation. S. suis was the most common cause of BM in this setting. Improved diagnostics are needed for meningoencephalitic syndromes to inform treatment and prevention strategies.