221 research outputs found

    Age-related Differences in Beta-range Electroencephalography Activity and Its Correlation with Postural Sway during Prolonged Quiet Stance

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    Falls are a multi-factorial, expensive, and recurring issue in the older population. This study focused on how age affects the cortical activity and its relationship with postural sway during stance. The research sample of eleven healthy, old (mean age = 71 yrs) and ten healthy, young (mean age = 23 yrs) volunteers wore electroencephalography (EEG) caps while balancing on force plates with their eyes closed in a narrow stance on both a hard surface (NEC) and a foam surface (FEC). The EEG power spectral density (PSD) maximum magnitude in the beta range (i.e. 13-30Hz) and the COP peak-to-peak range in the anterior-posterior (AP) and medial-lateral (ML) directions were extracted. The correlation between the EEG PSD and COP range and the corticokinetic coherence between the EEG and contralateral COP were computed. Using one-tailed t-tests, no significant group difference (p\u3e0.06) was found in the EEG PSD percent change between stance conditions. However, there were significant group differences in EEG-COP correlations in both directions (p\u3c0.001); with positive correlation coefficients for the young (mean= 0.29±0.27) and negative for the old (mean= -0.40±0.23). Significant corticokinetic coherence was found for all subjects under both conditions. These results demonstrate a direct communication between cortical activity and postural sway in young and older adults during stance. The cortical-sway relationship, however, is significantly altered in older adults, suggesting an age-related change in the modes of postural control that may be an important indicator for assessing fall-risk

    Discordant Responses to MAPK Pathway Stimulation Include Axonal Growths in Adult Drosophila Photoreceptors

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    Wallenda (WND) is the Drosophila member of a conserved family of dual leucine-zipper kinases (DLK) active in both neuronal regeneration and degeneration. We examined the role of WND over-expression on sensory neuron morphology by driving WND in multiple subtypes of Drosophila photoreceptors. WND overexpression under control of the pan-retinal GAL4 driver GMR causes multiple photoreceptor defects including cell death, rhabdomere degeneration, and axonal sprouting. Individual photoreceptor subtypes were assayed using GAL4 drivers specific for each photoreceptor class. Many R7 and R8 cells exhibit axonal sprouting while some show cell degeneration. Delaying the onset of WND overexpression until 20 days of age showed that older adult R7 cells retain the ability to initiate new axon growth. R1–6 photoreceptor cells degenerate in response to WND expression and exhibit rhodopsin loss and rhabdomere degeneration. RNAi knockdown of the MAPK signaling components Kayak (KAY) and Hemipterous (HEP) attenuates the WND-induced loss of Rh1 rhodopsin. UAS-induced HEP expression is similar to WND expression, causing degeneration in R1–6 photoreceptors and axonal sprouting in R7 photoreceptors. These results demonstrate that WND in adult Drosophila photoreceptor cells acts through MAPK signaling activity with both regenerative and degenerative responses. These photoreceptors provide a tractable experimental model to reveal cellular mechanisms driving contradictory WND signaling responses

    Extra‐nigral pathological conditions are common in Parkinson's disease with freezing of gait: An in vivo positron emission tomography study

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    Cholinergic denervation has been associated with falls and slower gait speed and β‐amyloid deposition with greater severity of axial motor impairments in Parkinson disease (PD). However, little is known about the association between the presence of extra‐nigral pathological conditions and freezing of gait (FoG). Patients with PD (n = 143; age, 65.5 ± 7.4 years, Hoehn and Yahr stage, 2.4 ± 0.6; Montreal Cognitive Assessment score, 25.9 ± 2.6) underwent [ 11 C]methyl‐4‐piperidinyl propionate acetylcholinesterase and [ 11 C]dihydrotetrabenazine dopaminergic PET imaging, and clinical, including FoG, assessment in the dopaminergic “off” state. A subset of subjects (n = 61) underwent [ 11 C]Pittsburgh compound‐B β‐amyloid positron emission tomography (PET) imaging. Normative data were used to dichotomize abnormal β‐amyloid uptake or cholinergic deficits. Freezing of gait was present in 20 patients (14.0%). Freezers had longer duration of disease ( P  = 0.009), more severe motor disease ( P  < 0.0001), and lower striatal dopaminergic activity ( P  = 0.013) compared with non‐freezers. Freezing of gait was more common in patients with diminished neocortical cholinergic innervation (23.9%, χ 2  = 5.56, P  = 0.018), but not in the thalamic cholinergic denervation group (17.4%, χ 2  = 0.26, P  = 0.61). Subgroup analysis showed higher frequency of FoG with increased neocortical β‐amyloid deposition (30.4%, Fisher Exact test: P  = 0.032). Frequency of FoG was lowest with absence of both pathological conditions (4.8%), intermediate in subjects with single extra‐nigral pathological condition (14.3%), and highest with combined neocortical cholinopathy and amyloidopathy (41.7%; Cochran‐Armitage trend test, Z  = 2.63, P  = 0.015). Within the group of freezers, 90% had at least one of the two extra‐nigral pathological conditions studied. Extra‐nigral pathological conditions, in particular the combined presence of cortical cholinopathy and amyloidopathy, are common in PD with FoG and may contribute to its pathophysiology. © 2014 International Parkinson and Movement Disorder SocietyPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108363/1/mds25929.pd

    Hubble Space Telescope Ultraviolet Spectroscopy of Fourteen Low-Redshift Quasars

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    We present low-resolution ultraviolet spectra of 14 low redshift (z<0.8) quasars observed with HST/STIS as part of a Snap project to understand the relationship between quasar outflows and luminosity. By design, all observations cover the CIV emission line. Nine of the quasars are from the Hamburg-ESO catalog, three are from the Palomar-Green catalog, and one is from the Parkes catalog. The sample contains a few interesting quasars including two broad absorption line (BAL) quasars (HE0143-3535, HE0436-2614), one quasar with a mini-BAL (HE1105-0746), and one quasar with associated narrow absorption (HE0409-5004). These BAL quasars are among the brightest known (though not the most luminous) since they lie at z<0.8. We compare the properties of these BAL quasars to the z1.4 Large Bright Quasar samples. By design, our objects sample luminosities in between these two surveys, and our four absorbed objects are consistent with the v ~ L^0.62 relation derived by Laor & Brandt (2002). Another quasar, HE0441-2826, contains extremely weak emission lines and our spectrum is consistent with a simple power-law continuum. The quasar is radio-loud, but has a steep spectral index and a lobe-dominated morphology, which argues against it being a blazar. The unusual spectrum of this quasar resembles the spectra of the quasars PG1407+265, SDSSJ1136+0242, and PKS1004+13 for which several possible explanations have been entertained.Comment: Uses aastex.cls, 21 pages in preprint mode, including 6 figures and 2 tables; accepted for publication in The Astronomical Journal (projected vol 133

    FilmArray, an Automated Nested Multiplex PCR System for Multi-Pathogen Detection: Development and Application to Respiratory Tract Infection

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    The ideal clinical diagnostic system should deliver rapid, sensitive, specific and reproducible results while minimizing the requirements for specialized laboratory facilities and skilled technicians. We describe an integrated diagnostic platform, the “FilmArray”, which fully automates the detection and identification of multiple organisms from a single sample in about one hour. An unprocessed biologic/clinical sample is subjected to nucleic acid purification, reverse transcription, a high-order nested multiplex polymerase chain reaction and amplicon melt curve analysis. Biochemical reactions are enclosed in a disposable pouch, minimizing the PCR contamination risk. FilmArray has the potential to detect greater than 100 different nucleic acid targets at one time. These features make the system well-suited for molecular detection of infectious agents. Validation of the FilmArray technology was achieved through development of a panel of assays capable of identifying 21 common viral and bacterial respiratory pathogens. Initial testing of the system using both cultured organisms and clinical nasal aspirates obtained from children demonstrated an analytical and clinical sensitivity and specificity comparable to existing diagnostic platforms. We demonstrate that automated identification of pathogens from their corresponding target amplicon(s) can be accomplished by analysis of the DNA melting curve of the amplicon

    “Because of mchango, I give my baby gripe water so he sleeps and stops crying”: Exclusive breastfeeding and parents’ concerns about colic-like symptoms in infants under 6 months in Lake Zone, Tanzania

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    Background Effective social and behavior change strategies for exclusive breastfeeding (EBF) rely on understanding how families interpret infant behavior and provide care. Little research thoroughly explores household use of non-prescribed medicine for infants under 6 months in rural Tanzania, which can interrupt EBF and may have other harmful unintended effects. Aim To explore parents’ use of non-prescribed medicine in response to infants’ colic-like symptoms during the EBF period. Methods We conducted thematic analysis of a series of qualitative, semi-structured interviews with 36 mothers and 30 fathers of infants 0-6 months in Lake Zone, Tanzania. Here, we focus on emergent themes related to concerns about colic-like symptoms and global implications for public health practitioners. Results Parents reported concerns about excessive crying and perceived infant abdominal pain, attributed to a potentially serious disease state locally known as mchango. Most parents gave non-prescribed medicines (e.g. gripe water, oral traditional medicine, and/or other commercial medicines) to treat or prevent mchango and associated symptoms, often including infant crying. After receiving supportive counselling on soothing techniques, most were willing to avoid giving non-prescribed medicines. Some reported continued challenges attributed to mchango symptoms, namely inconsolable crying. Conclusion While symptoms of mchango reported in this study overlapped with colic symptoms, literature in Tanzania suggests, in some cases, mchango is perceived to have spiritual origins and potentially be dangerous if left untreated. Empathetic counseling can offer parents knowledge and skills to manage colic-like symptoms without using non-prescribed medicines. Health workers need clear messages and training on risks of non-prescribed medicines and Tanzanian legislation banning its promotion and distribution

    Performance of Three-Biomarker Immunohistochemistry for Intrinsic Breast Cancer Subtyping in the AMBER Consortium

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    Classification of breast cancer into intrinsic subtypes has clinical and epidemiologic importance. To examine accuracy of immunohistochemistry (IHC)-based methods for identifying intrinsic subtypes, a three-biomarker IHC panel was compared to the clinical record and RNA-based intrinsic (PAM50) subtypes

    Pre-Diagnostic Circulating Vitamin D and Risk of Melanoma in Men

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    PURPOSE: Various studies have examined the association between serum vitamin D levels and different cancers; however, this is the first prospective study of this association with melanoma risk. The aim of this study is to investigate the association between serum vitamin D [25(OH)D] levels and melanoma in a cohort of older, middle-aged Finnish male smokers. METHODS: We conducted a nested case-control study within the Alpha-Tocopherol Beta-Carotene Cancer Prevention (ATBC) Study. From the ATBC cohort, 368 subjects were chosen for our study; 92 participants that developed melanoma and 276 matched control subjects. At study baseline, lifestyle questionnaires and blood samples were collected. Serum 25(OH)D was modeled as three sets of categorical variables: clinically-defined categories, season-specific quartiles and season-adjusted residual quartiles. Conditional logistic regression was used to obtain odds ratios (ORs) and 95% confidence intervals (95% CIs) to estimate the association between circulating vitamin D and melanoma risk. RESULTS: Overall no association of serum 25(OH)D and melanoma risk was observed. A decreased risk of developing melanoma was observed in the middle categories compared to the lowest category, albeit not significant. CONCLUSION: Results indicate no association between serum 25(OH)D levels and melanoma. Additional studies, including possibly consortium efforts, are needed to investigate the association between serum 25(OH)D levels and risk of melanoma in larger, more diverse study populations

    Circulating 25-Hydroxyvitamin D and the Risk of Rarer Cancers: Design and Methods of the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers

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    The Cohort Consortium Vitamin D Pooling Project of Rarer Cancers (VDPP), a consortium of 10 prospective cohort studies from the United States, Finland, and China, was formed to examine the associations between circulating 25-hydroxyvitamin D (25(OH)D) concentrations and the risk of rarer cancers. Cases (total n = 5,491) included incident primary endometrial (n = 830), kidney (n = 775), ovarian (n = 516), pancreatic (n = 952), and upper gastrointestinal tract (n = 1,065) cancers and non-Hodgkin lymphoma (n = 1,353) diagnosed in the participating cohorts. At least 1 control was matched to each case on age, date of blood collection (1974–2006), sex, and race/ethnicity (n = 6,714). Covariate data were obtained from each cohort in a standardized manner. The majority of the serum or plasma samples were assayed in a central laboratory using a direct, competitive chemiluminescence immunoassay on the DiaSorin LIAISON platform (DiaSorin, Inc., Stillwater, Minnesota). Masked quality control samples included serum standards from the US National Institute of Standards and Technology. Conditional logistic regression analyses were conducted using clinically defined cutpoints, with 50–<75 nmol/L as the reference category. Meta-analyses were also conducted using inverse-variance weights in random-effects models. This consortium approach permits estimation of the association between 25(OH)D and several rarer cancers with high accuracy and precision across a wide range of 25(OH)D concentrations
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