936 research outputs found
Measuring the Impossible: an EU New and Emerging Science and Technologies Initiative Symposium
Platelet lysate maintains chondrogenic potential and promotes cartilage regeneration
cartilage.
We
report
the
biological
effect
of
the
platelet
lysate
(PL),
a
PRP
derivative,
on
primary
human
articular
chondrocytes
(HAC)
cultured
under
both
physiological
and
inflammatory
condition.
Added
to
the
culture
medium,
PL
induced
a
strong
mitogenic
response
in
the
chondrocytes.
The
in
vitro
expanded
cell
population
maintained
a
chondrogenic
re-‐differentiation
potential
as
revealed
by
micromass
culture
in
vitro
as
well
as
in
vivo
as
demonstrated
by
ectopic
cartilage
formation
in
nude
mice.
Furthermore,
in
chondrocytes
cultured
in
the
presence
of
the
pro-‐inflammatory
cytokine
IL-‐1α,
the
PL
induced
a
drastic
enhancement
of
the
synthesis
of
the
cytokines
IL-‐6
and
IL-‐8
and
of
NGAL,
a
lipocalin
expressed
in
cells
of
the
chondrogenic
lineage.
These
events
were
controlled
by
the
p38
MAP
kinase
and
NF-‐κΒ
pathways.
The
pro-‐inflammatory
effect
of
the
PL
was
a
transient
phenomenon.
In
fact,
after
an
initial
up
regulation,
we
observed
a
significant
reduction
of
the
NF-‐κΒ
activity
together
with
the
repression
of
the
inflammatory
enzyme
ciclooxygenase-‐2
(COX-‐2).
Moreover,
the
medium
of
chondrocytes
cultured
in
the
contemporary
presence
of
PL
and
IL-‐1α,
showed
a
significant
enhancement
of
the
chemoattractant
activity
versus
untreated
chondrocytes.
On
the
whole,
our
findings
support
the
concept
that
the
platelet
products
have
a
direct
beneficial
effect
on
articular
chondrocytes
and
at
the
same
time
could
drive
in
sequence
a
trans
Encapsulation of human articular chondrocytes into 3D hydrogel : phenotype and genotype characterization
This chapter is intended to provide a summary of the current materials used in cell encapsulation technology
as well as methods for evaluating the performance of cells encapsulated in a polymeric matrix. In
particular, it describes the experimental procedure to prepare a hydrogel matrix based on natural polymers
for encapsulating and culturing human articular chondrocytes with the interest in cartilage regeneration.
Protocols to evaluate the viability, proliferation, differentiation, and matrix production of
embedded cells are also described and include standard protocols such as the MTT and [3H] Thymidine
assays, reverse transcription polymerase chain reaction (RT-PCR) technique, histology, and immunohistochemistry
analysis. The assessment of cell distribution within the 3D hydrogel construct is also described
using APoTome analysis.(undefined
Measurement with Persons: A European Network
The European ‘Measuring the Impossible’ Network MINET promotes new research activities in measurement dependent on human perception and/or interpretation. This includes the perceived attributes of products and services, such as quality or desirability, and societal parameters such as security and well-being. Work has aimed at consensus about four ‘generic’ metrological issues: (1) Measurement Concepts & Terminology; (2) Measurement Techniques: (3) Measurement Uncertainty; and (4) Decision-making & Impact Assessment, and how these can be applied specificallyto the ‘Measurement of Persons’ in terms of ‘Man as a Measurement Instrument’ and ‘Measuring Man.’ Some of the main achievements of MINET include a research repository with glossary; training course; book; series of workshops;think tanks and study visits, which have brought together a unique constellation of researchers from physics, metrology,physiology, psychophysics, psychology and sociology. Metrology (quality-assured measurement) in this area is relativelyunderdeveloped, despite great potential for innovation, and extends beyond traditional physiological metrology in thatit also deals with measurement with all human senses as well as mental and behavioral processes. This is particularlyrelevant in applications where humans are an important component of critical systems, where for instance health andsafety are at stake
Novel injectable gel (system) as a vehicle for human articular chondrocytes in cartilage tissue regeneration
We developed a novel injectable carrageenan/fibrin/hyaluronic acid-based hydrogel with in situ
gelling properties to be seeded with chondrogenic cells and used for cartilage tissue engineering
applications. We first analysed the distribution within the hydrogel construct and the phenotype of
human articular chondrocytes (HACs) cultured for 3 weeks in vitro. We observed a statistically
significant increase in the cell number during the first 2 weeks and maintenance of cell
viability throughout the cell culture, together with the deposition/formation of a cartilage-specific
extracellular matrix (ECM). Taking advantage of a new in vivo model that allows the integration
between newly formed and preexisting cartilage in immunodeficient mice to be investigated, we
showed that injectable hydrogel seeded with human articular chondrocytes was able to regenerate
and repair an experimentally made lesion in bovine articular cartilage, thus demonstrating the
potential of this novel cell delivery system for cartilage tissue engineering.The authors are grateful to Recco orthopaedic staff members for the collaboration and patients for bioptic material donation as well as to Mrs Daniela Marubbi for histological assistance. This work was supported by funds from the Italian MUR (FIRB-Tissuenet project), the European Union-funded STREP project, HIPPOCRATES (Grant No. NMP3-CT-2003-505758) and the European NoE EXPERTISSUES project (Grant No. NMP3-CT-2004-500283)
A preliminary approach to the multilabel classification problem of Portuguese juridical documents
Portuguese juridical documents from Supreme Courts and the Attorney General’s Office are manually classified by juridical experts into a set of classes belonging to a taxonomy of concepts. In this paper, a preliminary approach to develop techniques to automat- ically classify these juridical documents, is proposed. As basic strategy, the integration of natural language processing techniques with machine learning ones is used. Support Vector Machines (SVM) are used as learn- ing algorithm and the obtained results are presented and compared with other approaches, such as C4.5 and Naive Bayes
A cartilage tissue engineering approach combining starch-polycaprolactone fibre mesh scaffolds with bovine articular chondrocytes
In the present work we originally tested the suitability
of corn starch-polycaprolactone (SPCL) scaffolds for
pursuing a cartilage tissue engineering approach. Bovine articular
chondrocytes were seeded on SPCL scaffolds under
dynamic conditions using spinner flasks (total of 4 scaffolds
per spinner flask using cell suspensions of 0.5×106 cells/ml)
and cultured under orbital agitation for a total of 6 weeks.
Poly(glycolic acid) (PGA) non-woven scaffolds and bovine
native articular cartilage were used as standard controls for
the conducted experiments. PGA is a kind of standard in
tissue engineering approaches and it was used as a control
in that sense. The tissue engineered constructs were characterized
at different time periods by scanning electron microscopy
(SEM), hematoxylin-eosin (H&E) and toluidine
blue stainings, immunolocalisation of collagen types I and II,
and dimethylmethylene blue (DMB) assay for glycosaminoglycans
(GAG) quantification assay. SEM results for SPCL
constructs showed that the chondrocytes presented normal
morphological features, with extensive cells presence at the
surface of the support structures, and penetrating the scaffolds
pores. These observations were further corroborated
by H&E staining. Toluidine blue and immunohistochemistry
exhibited extracellular matrix deposition throughout the 3D structure. Glycosaminoglycans, and collagen types I and II
were detected. However, stronger staining for collagen type
II was observed when compared to collagen type I. The PGA
constructs presented similar features toSPCLat the end of the
6 weeks. PGA constructs exhibited higher amounts of matrix
glycosaminoglycans when compared to the SPCL scaffolds.
However, we also observed a lack of tissue in the central
area of the PGA scaffolds. Reasons for these occurrences
may include inefficient cells penetration, necrosis due to high
cell densities, or necrosis related with acidic by-products
degradation. Such situation was not detected in the SPCL
scaffolds, indicating the much better biocompatibility of the
starch based scaffolds
Type X collagen synthesis during in vitro development of chick embryo tibial chondrocytes.
The employment of migrant nannies in the UK: negotiating social class in an open market for commoditised in-home care
Migrant women are important sources of labour in the commoditised in-home childcare sector in many regions of the UK. Jobs in this sector, which include nannies as well as au pairs, babysitters, housekeepers and mothers' helps, are often low paid and low status with pay and conditions being determined by employers' circumstances and whims. This article draws on primary data and secondary sources to illustrate the ways in which employers compare migrant nannies with British nannies and other childcare workers in terms of the social class and formal education levels of different groups, with the aim of explaining why migrants are perceived as high-quality candidates for what are often low-paid, low-status jobs. I argue that employers negotiate inter-class relations in this gendered form of employment by understanding their relationship with the migrant nannies they have employed in the context of broader global inequalities—these inequalities are then reproduced and reaffirmed in private homes and across UK culture and society
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