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Impaired β-glucocerebrosidase activity and processing in frontotemporal dementia due to progranulin mutations.
Loss-of-function mutations in progranulin (GRN) are a major autosomal dominant cause of frontotemporal dementia. Most pathogenic GRN mutations result in progranulin haploinsufficiency, which is thought to cause frontotemporal dementia in GRN mutation carriers. Progranulin haploinsufficiency may drive frontotemporal dementia pathogenesis by disrupting lysosomal function, as patients with GRN mutations on both alleles develop the lysosomal storage disorder neuronal ceroid lipofuscinosis, and frontotemporal dementia patients with GRN mutations (FTD-GRN) also accumulate lipofuscin. The specific lysosomal deficits caused by progranulin insufficiency remain unclear, but emerging data indicate that progranulin insufficiency may impair lysosomal sphingolipid-metabolizing enzymes. We investigated the effects of progranulin insufficiency on sphingolipid-metabolizing enzymes in the inferior frontal gyrus of FTD-GRN patients using fluorogenic activity assays, biochemical profiling of enzyme levels and posttranslational modifications, and quantitative neuropathology. Of the enzymes studied, only β-glucocerebrosidase exhibited impairment in FTD-GRN patients. Brains from FTD-GRN patients had lower activity than controls, which was associated with lower levels of mature β-glucocerebrosidase protein and accumulation of insoluble, incompletely glycosylated β-glucocerebrosidase. Immunostaining revealed loss of neuronal β-glucocerebrosidase in FTD-GRN patients. To investigate the effects of progranulin insufficiency on β-glucocerebrosidase outside of the context of neurodegeneration, we investigated β-glucocerebrosidase activity in progranulin-insufficient mice. Brains from Grn-/- mice had lower β-glucocerebrosidase activity than wild-type littermates, which was corrected by AAV-progranulin gene therapy. These data show that progranulin insufficiency impairs β-glucocerebrosidase activity in the brain. This effect is strongest in neurons and may be caused by impaired β-glucocerebrosidase processing
A comprehensive study of GRB 070125, a most energetic gamma ray burst
We present a comprehensive multiwavelength analysis of the bright, long
duration gamma-ray burst GRB 070125, comprised of observations in -ray,
X-ray, optical, millimeter and centimeter wavebands. Simultaneous fits to the
optical and X-ray light curves favor a break on day 3.78, which we interpret as
the jet break from a collimated outflow. Independent fits to optical and X-ray
bands give similar results in the optical bands but shift the jet break to
around day 10 in the X-ray light curve. We show that for the physical
parameters derived for GRB 070125, inverse Compton scattering effects are
important throughout the afterglow evolution. While inverse Compton scattering
does not affect radio and optical bands, it may be a promising candidate to
delay the jet break in the X-ray band. Radio light curves show rapid flux
variations, which are interpreted as due to interstellar scintillation, and are
used to derive an upper limit of cm on the radius of the
fireball in the lateral expansion phase of the jet. Radio light curves and
spectra suggest a high synchrotron self absorption frequency indicative of the
afterglow shock wave moving in a dense medium. Our broadband modeling favors a
constant density profile for the circumburst medium over a wind-like profile
(). However, keeping in mind the uncertainty of the parameters, it is
difficult to unambiguously distinguish between the two density profiles. Our
broadband fits suggest that \event is a burst with high radiative efficiency
().Comment: 50 pages, 33 figures, sty file included, Appeared in 20 Aug 2008
edition of Astrophysical Journa
Gender, age and the MBA: An analysis of extrinsic and intrinsic career benefits
Against the background of an earlier UK study, this paper presents the findings of a Canadian based survey of career benefits from the MBA. Results indicate firstly that gender and age interact to influence perceptions of career outcomes (young men gain most in terms of extrinsic benefits of career change and pay), and secondly that both men and women gain intrinsic benefits from the MBA. However, intrinsic benefits vary by gender: men in the study were more likely to say they gained confidence from having a fuller skill set while women were more likely to say they gained confidence from feelings of self worth; men emphasised how they had learned to give up control while women argued that they had gained a ‘voice’ in the organization. The role of the MBA in career self- management and the acquisition of key skills are examined as well as the implications for the design of programmes in meeting the varied need of men and women in different age groups
Cancer cells exploit an orphan RNA to drive metastatic progression.
Here we performed a systematic search to identify breast-cancer-specific small noncoding RNAs, which we have collectively termed orphan noncoding RNAs (oncRNAs). We subsequently discovered that one of these oncRNAs, which originates from the 3' end of TERC, acts as a regulator of gene expression and is a robust promoter of breast cancer metastasis. This oncRNA, which we have named T3p, exerts its prometastatic effects by acting as an inhibitor of RISC complex activity and increasing the expression of the prometastatic genes NUPR1 and PANX2. Furthermore, we have shown that oncRNAs are present in cancer-cell-derived extracellular vesicles, raising the possibility that these circulating oncRNAs may also have a role in non-cell autonomous disease pathogenesis. Additionally, these circulating oncRNAs present a novel avenue for cancer fingerprinting using liquid biopsies
The Carnegie Supernova Project: First Near-Infrared Hubble Diagram to z~0.7
The Carnegie Supernova Project (CSP) is designed to measure the luminosity
distance for Type Ia supernovae (SNe Ia) as a function of redshift, and to set
observational constraints on the dark energy contribution to the total energy
content of the Universe. The CSP differs from other projects to date in its
goal of providing an I-band {rest-frame} Hubble diagram. Here we present the
first results from near-infrared (NIR) observations obtained using the Magellan
Baade telescope for SNe Ia with 0.1 < z < 0.7. We combine these results with
those from the low-redshift CSP at z <0.1 (Folatelli et al. 2009). We present
light curves and an I-band Hubble diagram for this first sample of 35 SNe Ia
and we compare these data to 21 new SNe Ia at low redshift. These data support
the conclusion that the expansion of the Universe is accelerating. When
combined with independent results from baryon acoustic oscillations (Eisenstein
et al. 2005), these data yield Omega_m = 0.27 +/- 0.0 (statistical), and
Omega_DE = 0.76 +/- 0.13 (statistical) +/- 0.09 (systematic), for the matter
and dark energy densities, respectively. If we parameterize the data in terms
of an equation of state, w, assume a flat geometry, and combine with baryon
acoustic oscillations, we find that w = -1.05 +/- 0.13 (statistical) +/- 0.09
(systematic). The largest source of systematic uncertainty on w arises from
uncertainties in the photometric calibration, signaling the importance of
securing more accurate photometric calibrations for future supernova cosmology
programs. Finally, we conclude that either the dust affecting the luminosities
of SNe Ia has a different extinction law (R_V = 1.8) than that in the Milky Way
(where R_V = 3.1), or that there is an additional intrinsic color term with
luminosity for SNe Ia independent of the decline rate.Comment: 44 pages, 23 figures, 9 tables; Accepted for publication in the
Astrophysical Journa
How are falls and fear of falling associated with objectively measured physical activity in a cohort of community-dwelling older men?
BACKGROUND: Falls affect approximately one third of community-dwelling older adults each year and have serious health and social consequences. Fear of falling (FOF) (lack of confidence in maintaining balance during normal activities) affects many older adults, irrespective of whether they have actually experienced falls. Both falls and fear of falls may result in restrictions of physical activity, which in turn have health consequences. To date the relation between (i) falls and (ii) fear of falling with physical activity have not been investigated using objectively measured activity data which permits examination of different intensities of activity and sedentary behaviour.
METHODS: Cross-sectional study of 1680 men aged 71-92 years recruited from primary care practices who were part of an on-going population-based cohort. Men reported falls history in previous 12 months, FOF, health status and demographic characteristics. Men wore a GT3x accelerometer over the hip for 7 days.
RESULTS: Among the 12% of men who had recurrent falls, daily activity levels were lower than among non-fallers; 942 (95% CI 503, 1381) fewer steps/day, 12(95% CI 2, 22) minutes less in light activity, 10(95% CI 5, 15) minutes less in moderate to vigorous PA [MVPA] and 22(95% CI 9, 35) minutes more in sedentary behaviour. 16% (n = 254) of men reported FOF, of whom 52% (n = 133) had fallen in the past year. Physical activity deficits were even greater in the men who reported that they were fearful of falling than in men who had fallen. Men who were fearful of falling took 1766(95% CI 1391, 2142) fewer steps/day than men who were not fearful, and spent 27(95% CI 18, 36) minutes less in light PA, 18(95% CI 13, 22) minutes less in MVPA, and 45(95% CI 34, 56) minutes more in sedentary behaviour. The significant differences in activity levels between (i) fallers and non-fallers and (ii) men who were fearful of falling or not fearful, were mediated by similar variables; lower exercise self-efficacy, fewer excursions from home and more mobility difficulties.
CONCLUSIONS: Falls and in particular fear of falling are important barriers to older people gaining health benefits of walking and MVPA. Future studies should assess the longitudinal associations between falls and physical activity
The Peculiar SN 2005hk: Do Some Type Ia Supernovae Explode as Deflagrations?
We present extensive u'g'r'i'BVRIYJHKs photometry and optical spectroscopy of
SN 2005hk. These data reveal that SN 2005hk was nearly identical in its
observed properties to SN 2002cx, which has been called ``the most peculiar
known type Ia supernova.'' Both supernovae exhibited high ionization SN
1991T-like pre-maximum spectra, yet low peak luminosities like SN 1991bg. The
spectra reveal that SN 2005hk, like SN 2002cx, exhibited expansion velocities
that were roughly half those of typical type Ia supernovae. The R and I light
curves of both supernovae were also peculiar in not displaying the secondary
maximum observed for normal type Ia supernovae. Our YJH photometry of SN 2005hk
reveals the same peculiarity in the near-infrared. By combining our optical and
near-infrared photometry of SN 2005hk with published ultraviolet light curves
obtained with the Swift satellite, we are able to construct a bolometric light
curve from ~10 days before to ~60 days after B maximum. The shape and unusually
low peak luminosity of this light curve, plus the low expansion velocities and
absence of a secondary maximum at red and near-infrared wavelengths, are all in
reasonable agreement with model calculations of a 3D deflagration which
produces ~0.25 M_sun of 56Ni.Comment: Accepted by PASP, to appear in April 2007 issue, 63 pages, 16
figures, 11 table
Trends in prevalence, mortality, and morbidity associated with high systolic blood pressure in Brazil from 1990 to 2017 : estimates from the “Global Burden of Disease 2017” (GBD 2017) study
Background: Hypertension remains the leading risk factor for cardiovascular disease (CVD) worldwide, and its impact in Brazil should be assessed in order to better address the issue. We aimed to describe trends in prevalence and burden of disease attributable to high systolic blood pressure (HSBP) among Brazilians ≥ 25 years old according to sex and federal units (FU) using the Global Burden of Disease (GBD) 2017 estimates. Methods: We used the comparative risk assessment developed for the GBD study to estimate trends in attributable deaths and disability-adjusted life-years (DALY), by sex, and FU for HSBP from 1990 to 2017. This study included 14 HSBP-outcome pairs. HSBP was defined as ≥ 140 mmHg for prevalence estimates, and a theoretical minimum risk exposure level (TMREL) of 110–115 mmHg was considered for disease burden. We estimated the portion of deaths and DALYs attributed to HSBP. We also explored the drivers of trends in HSBP burden, as well as the correlation between disease burden and sociodemographic development index (SDI). Results: In Brazil, the prevalence of HSBP is 18.9% (95% uncertainty intervals [UI] 18.5–19.3%), with an annual 0.4% increase rate, while age-standardized death rates attributable to HSBP decreased from 189.2 (95%UI 168.5–209.2) deaths to 104.8 (95%UI 94.9–114.4) deaths per 100,000 from 1990 to 2017. In spite of that, the total number of deaths attributable to HSBP increased 53.4% and HSBP raised from 3rd to 1st position, as the leading risk factor for deaths during the period. Regarding total DALYs, HSBP raised from 4th in 1990 to 2nd cause in 2017. The main driver of change of HSBP burden is population aging. Across FUs, the reduction in the age-standardized death rates attributable to HSBP correlated with higher SDI. Conclusions: While HSBP prevalence shows an increasing trend, age-standardized death and DALY rates are decreasing in Brazil, probably as results of successful public policies for CVD secondary prevention and control, but suboptimal control of its determinants. Reduction was more significant in FUs with higher SDI, suggesting that the effect of health policies was heterogeneous. Moreover, HSBP has become the main risk factor for death in Brazil, mainly due to population aging
Lack of Detectable HIV-1–Specific CD8+ T Cell Responses in Zambian HIV-1–Exposed Seronegative Partners of HIV-1–Positive Individuals
Human immunodeficiency virus type 1 (HIV-1)–specific T cell responses were characterized in a blinded study involving infected individuals and their seronegative exposed uninfected (EU) partners from Lusaka, Zambia. HIV-1–specific T cell responses were detected ex vivo in all infected individuals and amplified, on average, 27-fold following in vitro expansion. In contrast, no HIV-1–specific T cell responses were detected in any of the EU partners ex vivo or following in vitro expansion. These data demonstrate that the detection of HIV-1–specific T cell immunity in EU individuals is not universal and that alternative mechanisms may account for protection in these individuals
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