2,065 research outputs found
Milieu-adopted in vitro and in vivo differentiation of mesenchymal tissues derived from different adult human CD34-negative progenitor cell clones
Adult mesenchymal stem cells with multilineage differentiation potentially exist in the bone marrow, but have also been isolated from the peripheral blood. The differentiation of stem cells after leaving their niches depends predominately on the local milieu and its new microenvironment, and is facilitated by soluble factors but also by the close cell-cell interaction in a three-dimensional tissue or organ system. We have isolated CD34-negative, mesenchymal stem cell lines from human bone marrow and peripheral blood and generated monoclonal cell populations after immortalization with the SV40 large T-antigen. The cultivation of those adult stem cell clones in an especially designed in vitro environment, including self-constructed glass capillaries with defined growth conditions, leads to the spontaneous establishment of pleomorphic three-dimensional cell aggregates ( spheroids) from the monoclonal cell population, which consist of cells with an osteoblast phenotype and areas of mineralization along with well-vascularized tissue areas. Modifications of the culture conditions favored areas of bone-like calcifications. After the transplantation of the at least partly mineralized human spheroids into different murine soft tissue sites but also a dorsal skinfold chamber, no further bone formation could be observed, but angiogenesis and neovessel formation prevailed instead, enabling the transplanted cells and cell aggregates to survive. This study provides evidence that even monoclonal adult human CD34-negative stem cells from the bone marrow as well as peripheral blood can potentially differentiate into different mesenchymal tissues depending on the local milieu and responding to the needs within the microenvironment. Copyright (C) 2005 S. Karger AG, Basel
Clinical and functional characterisation of a novel TNFRSF1A c.605T > A/V173D cleavage site mutation associated with tumour necrosis factor receptor-associated periodic fever syndrome (TRAPS), cardiovascular complications and excellent response to etanercept treatment.
Objectives: To study the clinical outcome, treatment
response, T-cell subsets and functional consequences of a
novel tumour necrosis factor (TNF) receptor type 1
(TNFRSF1A) mutation affecting the receptor
cleavage site.
Methods: Patients with symptoms suggestive of tumour
necrosis factor receptor-associated periodic syndrome
(TRAPS) and 22 healthy controls (HC) were screened for
mutations in the TNFRSF1A gene. Soluble TNFRSF1A and
inflammatory cytokines were measured by ELISAs.
TNFRSF1A shedding was examined by stimulation of
peripheral blood mononuclear cells (PBMCs) with phorbol
12-myristate 13-acetate followed by flow cytometric
analysis (FACS). Apoptosis of PBMCs was studied by
stimulation with TNFa in the presence of cycloheximide
and annexin V staining. T cell phenotypes were monitored
by FACS.
Results: TNFRSF1A sequencing disclosed a novel V173D/
p.Val202Asp substitution encoded by exon 6 in one
family, the c.194–14G.A splice variant in another and
the R92Q/p.Arg121Gln substitution in two families.
Cardiovascular complications (lethal heart attack and
peripheral arterial thrombosis) developed in two V173D
patients. Subsequent etanercept treatment of the V173D
carriers was highly effective over an 18-month follow-up
period. Serum TNFRSF1A levels did not differ between
TRAPS patients and HC, while TNFRSF1A cleavage from
monocytes was significantly reduced in V173D and R92Q
patients. TNFa-induced apoptosis of PBMCs and T-cell
senescence were comparable between V173D patients
and HC.
Conclusions: The TNFRSF1A V173D cleavage site
mutation may be associated with an increased risk for
cardiovascular complications and shows a strong
response to etanercept. T-cell senescence does not seem
to have a pathogenetic role in affected patients
The solar oxygen-isotopic composition: Predictions and implications for solar nebula processes
The outer layers of the Sun are thought to preserve the average isotopic and chemical composition of the solar system. The solar O-isotopic composition is essentially unmeasured, though models based on variations in meteoritic materials yield several predictions. These predictions are reviewed and possible variations on these predictions are explored. In particular, the two-component mixing model of Clayton and Mayeda (1984) (slightly revised here) predicts solar compositions to lie along an extension of the calcium-aluminum-rich inclusion (CAI) ^(16)O line between (δ^(18)O, δ^(17)O) = (16.4, 11.4)%0 and (12.3, 7.5)%0. Consideration of data from ordinary chondrites suggests that the range of predicted solar composition should extend to slightly lower δ^(18)O values. The predicted solar composition is critically sensitive to the solid/gas ratio in the meteorite-forming region, which is often considered to be significantly enriched over solar composition. A factor of two solid/gas enrichment raises the predicted solar (δ^(18)O, δ^(17)O) values along an extension of the CAI ^(16)O line to (33, 28)%0. The model is also sensitive to the nebular O gas phase. If conversion of most of the gaseous O from CO to H_2O occurred at relatively low temperatures and was incomplete at the time of CM aqueous alteration, the predicted nebular gas composition (and hence the solar composition) would be isotopically heavier along a slope 1/2 line. The likelihood of having a single solid nebular O component is discussed. A distribution of initial solid compositions along the CAI ^(16)O line (rather than simply as an end-member) would not significantly change the predictions above in at least one scenario. Even considering these variations within the mixing model, the predicted range of solar compositions is distinct from that expected if the meteoritic variations are due to non-mass-dependent fractionation. Thus, a measurement of the solar O composition to a precision of several permil would clearly distinguish between these theories and should clarify a number of other important issues regarding solar system formation
Web-based database for the management of tissue specimens in a transregional histological research facility
BACKGROUND: In the setting of a histological research core facility sample tracking and project specific archiving of tissue specimens and communication of related data is of central importance. DESCRIPTION: Over a 24-month period 10 laboratories from two transregional research centers submitted in excess of 3000 tissue samples for histological processing and evaluation to our core facility. A web based database was set up to overcome the logistical problem of managing samples with inconsistent, duplicate and missing labels and to allow for efficient sample tracking, archiving and communication with the collaborating research laboratories. The database allows the users to remotely generate unique sample identifiers and enter sample annotation prior to sample processing. Furthermore the database facilitates communication about experimental set-up results and media files such as histological images. CONCLUSION: Our newly constructed web based portal is an important tool for the management of research samples of our histological core facility and facilitates significantly interdisciplinary and transregional research. It is freely available for scientific use
An operative gamma camera for sentinel lymph node procedure in case of breast cancer
Large field of view gamma cameras are widely used to perform lymphoscintigraphy in the sentinel lymph nodes (SLN) procedure in case of breast cancer. However, they are not specified for this application and their sizes do not enable their use in the operative room to control the excision of the all SLN. We present the results obtained with a prototype of a new mini gamma camera developed especially for the operative lymphoscintigraphy of the axillary area in case of breast cancer. This prototype is composed of 10 mm thick parallel lead collimator, a 2 mm thick GSO:Ce inorganic scintillating crystal from Hitachi and a Hamamatsu H8500 flat panel multianode (64 channels) photomultiplier tube (MAPMT) equipped with a dedicated electronics. Its actual field of view is 50 × 50mm2. The gamma interaction position in the GSO scintillating plate is obtained by calculating the center of gravity of the fired MAPMT channels. The measurements performed with this prototype demonstrate the usefulness of this mini gamma camera for the pre, per and post-operative identification of SLN's and how its complementary role with an intraoperative handheld gamma probe enables to improve the efficiency of this practice. A 100 × 100mm2 field of view camera designated to cover the entire axillary area is under investigation
Wikipedia as an encyclopaedia of life
In his 2003 essay E O Wilson outlined his vision for an “encyclopaedia of life” comprising “an electronic page for each species of organism on Earth”, each page containing “the scientific name of the species, a pictorial or genomic presentation of the primary type specimen on which its name is based, and a summary of its diagnostic traits.” Although the “quiet revolution” in biodiversity informatics has generated numerous online resources, including some directly inspired by Wilson's essay (e.g., "http://ispecies.org":http://ispecies.org, "http://www.eol.org":http://www.eol.org), we are still some way from the goal of having available online all relevant information about a species, such as its taxonomy, evolutionary history, genomics, morphology, ecology, and behaviour. While the biodiversity community has been developing a plethora of databases, some with overlapping goals and duplicated content, Wikipedia has been slowly growing to the point where it now has over 100,000 pages on biological taxa. My goal in this essay is to explore the idea that, largely independent of the efforts of biodiversity informatics and well-funded international efforts, Wikipedia ("http://en.wikipedia.org/wiki/Main_Page":http://en.wikipedia.org/wiki/Main_Page) has emerged as potentially the best platform for fulfilling E O Wilson’s vision
Coating dog kibble with a commercial liquid acidifier reduces the risk of Salmonella cross-contamination
Citation: Huss, A. R., Deliephan, A., Fuller, J. C., & Jones, C. K. (2016). Coating dog kibble with a commercial liquid acidifier reduces the risk of Salmonella cross-contamination. Journal of Animal Science, 94, 102-102. doi:10.2527/msasas2016-216In recent years, several pet food recalls have been attributed to Salmonella contamination. In addition to the negative impacts on animal health, pet foods contaminated with Salmonella have been linked to infection in humans. To help reduce the risks to humans, the Food and Drug Administration has set forth a zero-tolerance policy for Salmonella in pet foods. Typically, the preconditioner and extruder operate at sufficient temperatures to destroy pathogenic bacteria. However, there is the potential for post-processing cross-contamination to adulterate the product. One potential method to reduce the risk of Salmonella cross-contamination in pet foods is through the addition of chemical additive coatings. The objective of this research was to evaluate the ability of the liquid acid, ?-hydroxy-?-methylbutyric acid (HMB; Metabolic Technologies Inc, Ames, IA), to reduce cross-contamination of dry extruded dog kibble with Salmonella. Liquid HMB was applied to a single formula of dog kibble at inclusion levels of 0, 0.9 and 1.5% (w:w) using a laboratory-scale mixer. The coated kibbles were then inoculated with Salmonella enterica subsp. enterica Serovar Enteritidis (ATCC 13076), grown in trypticase soy broth (TSB). Inoculated kibbles were enumerated for Salmonella on d 0, 1, 2, 7, and 14 post-inoculation. For enumerations, a subsample was collected, serial diluted and spread plated to Xylose Lysine Deoxycholate (XLD) agar. All inoculated plates were incubated at 37°C for 24 h, after which black colonies, typical for Salmonella, were counted and cfu/g calculated. The effects of HMB concentration, enumeration day and their interaction were all significant (P < 0.0001) on the resulting Salmonella concentration. Salmonella counts from Day 0 were 6.99, 5.59, and 4.88 log10 cfu/g for 0, 0.9 and 1.5% HMB, respectively. For HMB levels of 0.9 and 1.5%, counts were below the detectable limit for d 1, 2, 7, and 14. For 0% HMB, the Salmonella counts were found to decrease over time to 4.80, 3.99, 2.80, and 3.14 log10 cfu/g for d 1, 2, 7, and 14, respectively. Overall, the HMB coating was effective at reducing Salmonella artificially inoculated to dog kibbles. Further research is warranted to evaluate the minimum effective dose of HMB to reduce Salmonella in dog and cat kibbles
Constraining regional glacier reconstructions using past ice thickness of deglaciating areas – a case study in the European Alps
In order to assess future glacier evolution and
meltwater runoff, accurate knowledge on the volume and the ice thickness
distribution of glaciers is crucial. However, in situ observations of
glacier thickness are sparse in many regions worldwide due to the difficulty
of undertaking field surveys. This lack of in situ measurements can be
partially overcome by remote-sensing information. Multi-temporal and
contemporaneous data on glacier extent and surface elevation provide past
information on ice thickness for retreating glaciers in the newly
deglacierized regions. However, these observations are concentrated near the
glacier snouts, which is disadvantageous because it is known to introduce
biases in ice thickness reconstruction approaches. Here, we show a strategy
to overcome this generic limitation of so-called retreat thickness
observations by applying an empirical relationship between the ice viscosity
at locations with in situ observations and observations from digital elevation model (DEM) differencing at the glacier margins. Various datasets from the European
Alps are combined to model the ice thickness distribution of Alpine glaciers
for two time steps (1970 and 2003) based on the observed thickness in regions
uncovered from ice during the study period. Our results show that the
average ice thickness would be substantially underestimated (∼ 40 %) when relying solely on thickness observations from previously
glacierized areas. Thus, a transferable topography-based viscosity scaling
is developed to correct the modelled ice thickness distribution. It is shown
that the presented approach is able to reproduce region-wide glacier
volumes, although larger uncertainties remain at a local scale, and thus might
represent a powerful tool for application in regions with sparse
observations.</p
Phase correlation of laser waves with arbitrary frequency spacing
The theoretically predicted correlation of laser phase fluctuations in
Lambda-type interaction schemes is experimentally demonstrated. We show, that
the mechanism of correlation in a Lambda scheme is restricted to high frequency
noise components, whereas in a double- scheme, due to the laser phase
locking in closed-loop interaction, it extends to all noise frequencies. In
this case the correlation is weakly sensitive to coherence losses. Thus the
double-Lambda scheme can be used to correlate e.m. fields with carrier
frequency differences beyond the GHz regime.Comment: 4 pages, 4 figure
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