473 research outputs found
Differential gene expression in multiple neurological, inflammatory and connective tissue pathways in a spontaneous model of human small vessel stroke
Aims:
Cerebral small vessel disease (SVD) causes a fifth of all strokes plus diffuse brain damage leading to cognitive decline, physical disabilities and dementia. The aetiology and pathogenesis of SVD are unknown, but largely attributed to hypertension or microatheroma.
Methods:
We used the spontaneously hypertensive stroke-prone rat (SHRSP), the closest spontaneous experimental model of human SVD, and age-matched control rats kept under identical, non-salt-loaded conditions, to perform a blinded analysis of mRNA microarray, qRT-PCRand pathway analysis in two brain regions (frontal and midcoronal) commonly affected by SVD in the SHRSP at age five, 16 and 21 weeks.
Results:
We found gene expression abnormalities, with fold changes ranging from 2.5 to 59 for the 10 most differentially expressed genes, related to endothelial tight junctions (reduced), nitric oxide bioavailability (reduced), myelination (impaired), glial and microglial activity (increased), matrix proteins (impaired), vascular reactivity (impaired) and albumin (reduced), consistent with protein expression defects in the same rats. All were present at age 5 weeks thus pre-dating blood pressure elevation. âNeurologicalâ and âinflammatoryâ pathways were more affected than âvascularâ functional pathways.
Conclusions:
This set of defects, although individually modest, when acting in combination could explain the SHRSP's susceptibility to microvascular and brain injury, compared with control rats. Similar combined, individually modest, but multiple neurovascular unit defects, could explain susceptibility to spontaneous human SVD
Functional Enhancement of Electrofusion-derived BRIN-BD11 Insulin-secreting Cells After Implantation into Diabetic Mice
Electrofusion-derived BRIN-BD11 cells are glucosesensitive
insulin-secreting cells which provide an
archetypal bioengineered surrogate β-cell for
insulin replacement therapy in diabetes mellitus,
5x106 BRIN-BD11 cells were implanted intraperitoneally
into severely hyperglycaemic (>24mmol/l)
streptozotocin-induced insulin-treated diabetic
athymic nude (nu/nu) mice. The implants reduced
hyperglycaemia such that insulin injections were
discontinued by 5â16 days (<17mmol/l) and normoglycaemia
(<9mmol/l) was achieved by 7â20
days. Implanted cells were removed after 28 days
and re-established in culture. After re-culture for 20
days, glucose-stimulated (16.7mmol/l) insulin
release was enhanced by 121% (p<0.001) compared
to non-implanted cells. Insulin responses to
glucagon-like peptide-1 (10â9mol/l), cholecystokinin-8 (10â8 mol/l) and L-alanine (10 mmol/l) were
increased by 32%, 31% and 68% respectively
(p<0.05â0.01). Insulin content of the cells was 148%
greater at 20 days after re-culture than before
implantation (p<0.001), but basal insulin release (at
5.6 mmol/l glucose) was not changed. After re-culture
for 40 days, insulin content declined to 68% of
the content before implantation (p<0.01), although
basal insulin release was unchanged. However, the
insulin secretory responses to glucose, glucagonlike
peptide-1, cholecystokinin-8 and L-alanine
were decreased after 40 days of re-culture to 65%,
72%, 73% and 42% respectively of the values before
implantation (p<0.05â0.01). The functional
enhancement of electrofusion-derived surrogate β-cells that were re-cultured for 20 days after implantation
and restoration of normoglycaemia indicates
that the in vivo environment could greatly assist β-cell engineering approaches to therapy for diabetes
Multi-wavelength aperture polarimetry of debris disc host stars
Debris discs around main sequence stars have been extensively characterised
from infrared to millimetre wavelengths through imaging, spectroscopic, and
total intensity (scattered light and/or thermal emission) measurements.
Polarimetric observations have only been used sparingly to interpret the
composition, structure, and size of dust grains in these discs. Here we present
new multi-wavelength aperture polarisation observations with parts-per-million
sensitivity of a sample of twelve bright debris discs, spanning a broad range
of host star spectral types, and disc properties. These measurements were
mostly taken with the HIgh Precision Polarimetric Instrument on the
Anglo-Australian Telescope. We combine these polarisation observations with the
known disc architectures and geometries of the discs to interpret the
measurements. We detect significant polarisation attributable to circumstellar
dust from HD 377 and HD 39060, and find tentative evidence for HD 188228 and HD
202628.Comment: 25 pages, 8 figures, 9 tables, accepted for publication in MNRA
Change of direction in the biomechanics of atherosclerosis
The non-uniform distribution of atherosclerosis within the arterial system has been attributed to pro-atherogenic influences of low, oscillatory haemodynamic wall shear stress (WSS) on endothelial cells (EC). This theory is challenged by the changes in lesion location that occur with age in human and rabbit aortas. Furthermore, a number of point-wise comparisons of lesion prevalence and WSS have failed to support it. Here we investigate the hypothesis that multidirectional flow-characterized as the average magnitude of WSS components acting transversely to the mean vector (transWSS)-plays a key role. Maps of lesion prevalence around aortic branch ostia in immature and mature rabbits were compared with equivalent maps of time average WSS, the OSI (an index characterizing oscillatory flow) and transWSS, obtained from computational simulations; Spearman's rank correlation coefficients were calculated for aggregated data and 95% confidence intervals were obtained by bootstrapping methods. Lesion prevalence correlated positively, strongly and significantly with transWSS at both ages. Correlations of lesion prevalence with the other shear metrics were not significant or were significantly lower than those obtained for transWSS. No correlation supported the low, oscillatory WSS theory. The data are consistent with the view that multidirectional near-wall flow is highly pro-atherogenic. Effects of multidirectional flow on EC, and methods for investigating them, are reviewed. The finding that oscillatory flow has pro-inflammatory effects when acting perpendicularly to the long axis of EC but anti-inflammatory effects when acting parallel to it may explain the stronger correlation of lesion prevalence with transWSS than with the OSI
âIt just makes me feel a little less aloneâ a qualitative exploration of the podcast âmenopause unmutedâ on women's perceptions of menopause
Objective:
Menopause can negatively impact women's quality of life, with many women reporting inadequate information and support. Podcasts have grown in popularity in recent years and have been found to be accessible methods for increasing knowledge and challenging perceptions of stigmatized topics. The current research aimed to understand the impact of the podcast âmenopause: unmutedâ on women's menopause-related knowledge, understanding, and communication practices.
Methods:
A diverse sample of 30 women aged 40 to 60 years listened to the podcast series, which focused on menopause stories, before taking part in semistructured interviews to discuss the impact of the podcast on how they understood and communicated about menopause. The interviews were analyzed thematically.
Results:
Two overarching themes were identified in the data. A âjourney of knowledge gainâ explores participantsâ understanding of menopause before listening to the podcast and describes how this is deepened by hearing and connecting with women's stories. âReframing menopauseâ describes the impact of the podcast, where women reflect on the value of communication amongst women, challenge and re-evaluate the stigmatization of menopause, and discuss ways to make positive behavioral changes in their lives.
Conclusions:
The podcast âmenopause: unmutedâ helped women to learn about the menopause experience, have a greater sense of belonging to a community of women, and feel empowered to make changes in their own lives. Sharing stories via podcasts has potential as an accessible and impactful medium to educate women and reduce the widespread stigma associated with menopause
Estimating arterial cyclic strain from the spacing of endothelial nuclei
Background:
The non-uniform distribution of atherosclerosis within the arterial system is widely attributed to variation in haemodynamic wall shear stress. It may also depend on variation in pressure-induced stresses and strains within the arterial wall; these have been less widely investigated, at least in part because of a lack of suitable techniques.
Objectives:
Here we show that local arterial strain can be determined from impressions left by endothelial cells on the surface of vascular corrosion casts made at different pressures, even though only one pressure can be examined in each vessel. The pattern of pits in the cast caused by protruding endothelial nuclei was subject to âretro-deformationâ to identify the pattern that would have occurred in the absence of applied stresses.
Methods:
Retaining the nearest-neighbour pairs found under this condition, changes in nearest-neighbour vectors were calculated for the pattern seen in the cast, and the ratio of mean changes at different pressures determined. This approach removes errors in simple nearest-neighbour analyses caused by the nearest neighbour changing as deformation occurs.
Results:
The accuracy, precision and robustness of the approach were validated using simulations. The method was implemented using confocal microscopy of casts of the rabbit aorta made at systolic and diastolic pressures; results agreed well with the ratio of the macroscopic dimensions of the casts.
Conclusions:
Applying the new technique to areas around arterial branches could support or refute the hypothesis that the development of atherosclerosis is influenced by mural strain, and the method may be applicable to other tissues
"You're more engaged when you're listening to somebody tell their story": A qualitative exploration into the mechanisms of the podcast 'menopause: unmuted' for communicating health information.
While health podcasts can be effective in reducing stigma and increasing knowledge, we know little about their mechanisms of action. This qualitative study explored the mechanisms of how women connected with the podcast 'menopause: unmuted', which presented menopause information in a storytelling format. A diverse sample of 30 women aged 40-60 years were interviewed after listening to the podcast. Interviews covered participant's views and perceptions of the stories presented. Transcripts were analyzed thematically. Two overarching themes were identified. 'Openness and authenticity' describes the value of personal stories told in an authentic way by real experts-by-experience. 'Relatability and representation' explores participants' emotional reaction to the podcast, influenced by the extent to which they identified with the stories and storytellers on the podcast. Authenticity and relatability were identified as key mechanisms through which participants connected with audio stories, consistent with Fisher's narrative theory. These findings have important implications for the application of storytelling in podcasts designed to influence health behaviors. Diverse stories representing a range of demographic characteristics and experiences are needed when creating podcasts about health information to increase listener's relatability and connection. [Abstract copyright: Copyright Š 2022 The Authors. Published by Elsevier B.V. All rights reserved.
Effects of dietary salt on gene and protein expression in brain tissue of a model of sporadic small vessel disease
Background: The effect of salt on cerebral small vessel disease (SVD) is poorly
understood. We assessed the effect of dietary salt on the cerebral tissue of the strokeprone spontaneously hypertensive rat (SHRSP) - a relevant model of sporadic SVD - at both the gene and protein level.
Methods: Brains from 21 week old SHRSP and Wistar-Kyoto rats, half additionally salt-loaded (via a 3 week regime of 1% NaCl in drinking water) were split into 2 hemispheres and sectioned coronally â one hemisphere for mRNA microarray and qRT-PCR, the other for immunohistochemistry using a panel of antibodies targeting components of the neurovascular unit.
Results: We observed differences in gene and protein expression affecting the acute phase pathway and oxidative stress (ALB, AMBP, APOH, AHSG and LOC100129193, up-regulated in salt-loaded WKY versus WKY, >2-fold), active microglia (increased Iba-1 protein expression in salt-loaded SHRSP versus saltloaded WKY, p<0.05), vascular structure (ACTB & CTNNB, up-regulated in saltloaded SHRSP versus SHRSP, >3-fold; CLDN-11,VEGF and VGF downregulated >- 2-fold in salt-loaded SHRSP versus SHRSP) and myelin integrity (MBP downregulated in salt loaded WKY rats versus WKY, >2.5-fold). Changes of salt-loading were more pronounced in SHRSP and occurred without an increase in blood pressure in WKY rats.
Conclusion: Salt exposure induced changes in gene and protein expression in an experimental model of SVD and its parent rat strain in multiple pathways involving components of the glio-vascular unit. Further studies in pertinent experimental models at different ages would help clarify the short and long-term effect of dietary salt in SVD
The impact of a single round of community mass treatment with azithromycin on disease severity and ocular Chlamydia trachomatis load in treatment-naĂŻve trachoma-endemic island communities in West Africa.
BACKGROUND: Trachoma, a neglected tropical disease, is caused by ocular infection with Chlamydia trachomatis (Ct). The World Health Organization (WHO) recommends three annual rounds of community mass drug treatment with azithromycin (MDA) if the prevalence of follicular trachoma in 1-9 year olds (TF1-9) exceeds 10% at district level to achieve an elimination target of district-level TF1-9 below 5% after. To evaluate this strategy in treatment-naĂŻve trachoma-endemic island communities in Guinea Bissau, we conducted a cross-sectional population-based trachoma survey on four islands. The upper tarsal conjunctivae of each participant were clinically assessed for trachoma and conjunctival swabs were obtained (n = 1507). We used a droplet digital PCR assay to detect Ct infection and estimate bacterial load. We visited the same households during a second cross-sectional survey and repeated the ocular examination and obtained conjunctival swabs from these households one year after MDA (n = 1029). RESULTS: Pre-MDA TF1-9 was 22.0% (136/618). Overall Ct infection prevalence (CtI) was 18.6% (25.4% in 1-9 year olds). Post-MDA (estimated coverage 70%), TF1-9 and CtI were significantly reduced (7.4% (29/394, P < 0.001) and 3.3% (34/1029, P < 0.001) (6.6% in 1-9 year olds, P < 0.001), respectively. Median ocular Ct load was reduced from 2038 to 384 copies/swab (P < 0.001). Following MDA cases of Ct infection were highly clustered (Moran's I 0.27, P < 0.001), with fewer clusters of Ct infection overall, fewer clusters of cases with high load infections and less severe disease. CONCLUSIONS: Despite a significant reduction in the number of clusters of Ct infection, mean Ct load, disease severity and presence of clusters of cases of high load Ct infection suggesting the beginning of trachoma control in isolated island communities, following a single round of MDA we demonstrate that transmission is still ongoing. These detailed data are useful in understanding the epidemiology of ocular Ct infection in the context of MDA and the tools employed may have utility in determining trachoma elimination and surveillance activities in similar settings
The Grizzly, March 3, 1989
Quad Asbestos Cover-Up? ⢠UC Lip-synching Talents Shown at Airband ⢠Letters: Klee Clears Clutter; Fondots Tepid About Water; Students Concerned ⢠Bond is Back! ⢠Isaac\u27s Astounds Aussie ⢠Men\u27s Indoor Ready for Mainstream ⢠Youthful Bears Swim to 3rd ⢠Senior Trio Leads Ursinus ⢠McGowan\u27s Courage Inspiring ⢠Bears End Season Upbeat ⢠Send North Up The River?https://digitalcommons.ursinus.edu/grizzlynews/1231/thumbnail.jp
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