614 research outputs found
Mitochondrial DNA lineages of Italian Giara and Sarcidano horses
Giara and Sarcidano are 2 of the 15 extant native Italian horse breeds with limited dispersal capability that originated from a larger number of individuals. The 2 breeds live in two distinct isolated locations on the island of Sardinia. To determine the genetic structure and evolutionary history of these 2 Sardinian breeds, the first hypervariable segment of the mitochondrial DNA (mtDNA) was sequenced and analyzed in 40 Giara and Sarcidano horses and compared with publicly available mtDNA data from 43 Old World breeds. Four different analyses, including genetic distance, analysis of molecular variance, haplotype sharing, and clustering methods, were used to study the genetic relationships between the Sardinian and other horse breeds. The analyses yielded similar results, and the FST values indicated that a high percentage of the total genetic variation was explained by between-breed differences. Consistent with their distinct phenotypes and geographic isolation, the two Sardinian breeds were shown to consist of 2 distinct gene pools that had no gene flow between them. Giara horses were clearly separated from the other breeds examined and showed traces of ancient separation from horses of other breeds that share the same mitochondrial lineage. On the other hand, the data from the Sarcidano horses fit well with variation among breeds from the Iberian Peninsula and North-West Europe: genetic relationships among Sarcidano and the other breeds are consistent with the documented history of this breed
Electrospun silk fibroin fibers for storage and controlled release of human platelet lysate
Human platelet lysate (hPL) is a pool of growth factors and cytokines able to induce regeneration of different tissues. Despite its good potentiality as therapeutic tool for regenerative medicine applications, hPL has been only moderately exploited in this field. A more widespread adoption has been limited because of its rapid degradation at room temperature that decreases its functionality. Another limiting factor for its extensive use is the difficulty of handling the hPL gels. In this work, silk fibroin-based patches were developed to address several points: improving the handling of hPL, enabling their delivery in a controlled manner and facilitating their storage by creating a device ready to use with expanded shelf life. Patches of fibroin loaded with hPL were synthesized by electrospinning to take advantage of the fibrous morphology. The release kinetics of the material was characterized and tuned through the control of fibroin crystallinity. Cell viability assays, performed with primary human dermal fibroblasts, demonstrated that fibroin is able to preserve the hPL biological activity and prolong its shelf-life. The strategy of storing and preserving small active molecules within a naturally-derived, protein-based fibrous scaffold was successfully implemented, leading to the design of a biocompatible device, which can potentially simplify the storage and the application of the hPL on a human patient, undergoing medical procedures such as surgery and wound care. Statement of Significance: Human platelets lysate (hPL) is a mixture of growth factors and cytokines able to induce the regeneration of damaged tissues. This study aims at enclosing hPL in a silk fibroin electrospun matrix to expand its utilization. Silk fibroin showed the ability to preserve the hPL activity at temperature up to 60 \ub0C and the manipulation of fibroin's crystallinity provided a tool to modulate the hPL release kinetic. This entails the possibility to fabricate the hPL silk fibroin patches in advance and store them, resulting in an easy and fast accessibility and an expanded use of hPL for wound healing
Concordance of c-kit mutational status in matched primary and metastatic cutaneous canine mast cell tumors at baseline
BackgroundMutation analysis of proto-oncogene c-kit (c-kit) is advisable before starting treatment with tyrosine kinase inhibitors in dogs with mast cell tumor (MCT), including those with metastatic disease. Testing is usually performed on primary tumors, assuming that c-kit mutation status does not change in metastasis.Hypothesis/ObjectivesTo give an insight into the mutational processes and to make a recommendation on the use of c-kit mutational analysis in the clinical setting.AnimalsTwenty-one client-owned dogs with metastatic MCT.MethodsDogs undergoing resection or biopsy for both primary and matched metastatic MCT were prospectively enrolled. Total RNA or DNA was extracted from primary MCT and corresponding metastases. Exons 8, 9, and 11 were amplified by PCR and sequenced. Genetic features between primary MCT and metastases were compared. Their correlation with clinicopathologic features was investigated.ResultsConcordance (mutated or wild-type) of mutational status, evaluable in 21 primary and matched metastatic (20 nodal and 1 splenic) MCTs, was 100%. Three new c-kit mutations were identified. No significant correlation was detected between c-kit mutation and clinicopathologic features.Conclusions and Clinical ImportanceProto-oncogene c-kit mutational status is conserved between any primary and its matched secondary tumor, suggesting that both can be used for c-kit mutational testing. Targeted therapies might be also used to treat metastatic disease
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-Ââdifferentiation
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-Ââinflammatory
cytokine
IL-Ââ1α,
the
PL
induced
a
drastic
enhancement
of
the
synthesis
of
the
cytokines
IL-Ââ6
and
IL-Ââ8
and
of
NGAL,
a
lipocalin
expressed
in
cells
of
the
chondrogenic
lineage.
These
events
were
controlled
by
the
p38
MAP
kinase
and
NF-ÂâÎșÎ
pathways.
The
pro-Ââinflammatory
effect
of
the
PL
was
a
transient
phenomenon.
In
fact,
after
an
initial
up
regulation,
we
observed
a
significant
reduction
of
the
NF-ÂâÎșÎ
activity
together
with
the
repression
of
the
inflammatory
enzyme
ciclooxygenase-Ââ2
(COX-Ââ2).
Moreover,
the
medium
of
chondrocytes
cultured
in
the
contemporary
presence
of
PL
and
IL-Ââ1α,
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
Novel injectable gel encapsulating human articular chondrocytes for cartilage tissue repair and regeneration
[Excerpt] Cartilage tissue loss, as a result of trauma, congenital disorders and diseases of joints, involving structural damage of articular cartilage surface, is a substantial clinical problem representing a major
challenge for cartilage tissue engineering. The aim of our study was to evaluate the in vitro and in vivo behavior of human articular chondrocytes encapsulated within a novel carrageenan in situ injectable
hydrogel for cartilage tissue engineering and regeneration. Human articular chondrocytes (Hac) were expanded using a well defined serum free medium able to support cell proliferation and
differentiation with high cell chondrogenicity. [...]info:eu-repo/semantics/publishedVersio
Beta-tricalcium phosphate ceramic triggers fast and robust bone formation by human mesenchymal stem cells
Due to their osteoconductive and inductive properties, a variety of calcium phosphate (CaP) scaffolds are commonly used in orthopaedics as graft material to heal bone defects. In this study, we have used two CaP scaffolds with different hydroxyapatite (HA) and \u3b2-tricalcium phosphate (\u3b2-TCP) ratios (MBCP\uae; 60/40 and MBCP+\uae; 20/80) to investigate their intrinsic capacity to favour human bone marrow stem cells (hBMSCs) osteogenic differentiation capacity. We report that MBCP+\uae showed in in vitro culture model a higher rate of calcium ion release in comparison with MBCP\uae. In two defined coculture systems, the hBMSC seeded onto MBCP+\uae presented an increased amount of VEGF secretion, resulting in an enhanced endothelial cell proliferation and capillary formation compared with hBMSC seeded onto MBCP\uae. When both ceramics combined with hBMSC were implanted in a nude mouse model, we observed a faster osteogenic differentiation and enhancement mature bone deposition sustained by the presence of a vast host vasculature within the MBCP+\uae ceramics. Bone formation was observed in samples highly positive to the activation of calcium sensing receptor protein (CaSr) on the surface of seeded hBMSC that also shown higher BMP-2 protein expression. With these data we provide valuable insights in the possible mechanisms of ossification and angiogenesis by hBMSC that we believe to be primed by calcium ions released from CaP scaffolds. Evidences could lead to an optimization of ceramic scaffolds to prime bone repair
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)
Measurement with Persons: A European Network
The European âMeasuring the Impossibleâ 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 âgenericâ 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 âMeasurement of Personsâ in terms of âMan as a Measurement Instrumentâ and âMeasuring Man.â 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
A Modified Rabbit Ulna Defect Model for Evaluating Periosteal Substitutes in Bone Engineering: A Pilot Study
The present work defines a modified critical size rabbit ulna defect model for bone regeneration in which a non-resorbable barrier membrane was used to separate the radius from
the ulna to create a valid model for evaluation of tissue-engineered periosteal substitutes.
Eight rabbits divided into two groups were used. Critical defects (15 mm) were made
in the ulna completely eliminating periosteum. For group I, defects were filled with a
nanohydroxyapatite poly(ester urethane) scaffold soaked in PBS and left as such (group
Ia) or wrapped with a tissue-engineered periosteal substitute (group Ib). For group II, an
expanded-polytetrafluoroethylene (e-PTFE) (GORE-TEX\uae) membrane was inserted around
the radius then the defects received either scaffold alone (group IIa) or scaffold wrapped
with periosteal substitute (group IIb). Animals were euthanized after 12\u201316 weeks, and
bone regeneration was evaluated by radiography, computed microtomography (\ub5CT), and
histology. In the first group, we observed formation of radio-ulnar synostosis irrespective
of the treatment. This was completely eliminated upon placement of the e-PTFE (GORETEX\uae) membrane in the second group of animals. In conclusion, modification of the model
using a non-resorbable e-PTFE membrane to isolate the ulna from the radius was a valuable
addition allowing for objective evaluation of the tissue-engineered periosteal substitut
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