153 research outputs found
Wetting morphologies on randomly oriented fibers
We characterize the different morphologies adopted by a drop of liquid placed
on two randomly oriented fibers, which is a first step toward understanding the
wetting of fibrous networks. The present work reviews previous modeling for
parallel and touching crossed fibers and extends it to an arbitrary orientation
of the fibers characterized by the tilting angle and the minimum spacing
distance. Depending on the volume of liquid, the spacing distance between
fibers and the angle between the fibers, we highlight that the liquid can adopt
three different equilibrium morphologies: (1) a column morphology in which the
liquid spreads between the fibers, (2) a mixed morphology where a drop grows at
one end of the column or (3) a single drop located at the node. We capture the
different morphologies observed using an analytical model that predicts the
equilibrium configuration of the liquid based on the geometry of the fibers and
the volume of liquid
Late Relapse and Follow-up Protocols in Testicular Germ Cell Tumours: The Edinburgh Cancer Centre Experience and Review of the Literature
Aims To identify clinicopathological features and outcomes in patients with late relapse (LR) of testicular germ cell tumours (GCTs) in order to guide follow-up policy. Materials and Methods The Edinburgh Cancer Centre (ECC) database identified all patients diagnosed with testicular GCT between 1988 and 2002. Of 703 patients, six relapsed more than 24 months after their initial treatment. A retrospective casenote review was performed to extract clinical, pathological, treatment and outcome data. Results Six patients (0.85%) underwent late relapse. All patients presented initially with stage I disease and five were classified as good risk (International Germ Cell Consensus Classification, IGCCC). Median time to LR was 31 months. Two patients had previously relapsed less than 24 months from initial diagnosis. Markers at the time of relapse were normal in all patients. In all cases of late relapse disease was confined to axial lymphadenopathy. Three patients were treated with chemotherapy alone, two patients underwent surgical resection and one patient received combined treatment. All patients obtained a complete response and all remain disease free with a median follow-up of 52 months. Conclusions The incidence of late relapse in this series is low. Chemo-naive patients with LR were successfully salvaged with chemotherapy alone and patients previously exposed to cisplatin-based chemotherapy were salvaged with complete surgical excision. The optimal length of follow-up in patients with testicular germ cell tumours is not known and practice varies widely. In this cohort of 703 patients, only one patient who relapsed was picked up by additional clinic follow-up between 5 and 10 years. Thus, on the basis of this small series, the authors suggest that follow-up after five years may not be justified
Functional decline after incident wrist fracturesâStudy of Osteoporotic Fractures: prospective cohort study
Objective To study the effect of an incident wrist fracture on functional status in women enrolled in the Study of Osteoporotic Fractures
European Network of Breast Development and Cancer turned 10 years: a growing family of mammary gland researchers
The European Network for Breast Development and Cancer (ENBDC), a worldwide network (http://www.enbdc.org/), celebrated its tenth anniversary with a fantastic meeting last March 15-17, 2018 in Weggis with 76 attendees
Ectodysplasin target gene Fgf20 regulates mammary bud growth and ductal invasion and branching during puberty
Mammary gland development begins with the appearance of epithelial placodes that invaginate, sprout, and branch to form small arborized trees by birth. The second phase of ductal growth and branching is driven by the highly invasive structures called terminal end buds (TEBs) that form at ductal tips at the onset of puberty. Ectodysplasin (Eda), a tumor necrosis factor-like ligand, is essential for the development of skin appendages including the breast. In mice, Eda regulates mammary placode formation and branching morphogenesis, but the underlying molecular mechanisms are poorly understood. Fibroblast growth factor (Fgf) receptors have a recognized role in mammary ductal development and stem cell maintenance, but the ligands involved are ill-defined. Here we report that Fgf20 is expressed in embryonic mammary glands and is regulated by the Eda pathway. Fgf20 deficiency does not impede mammary gland induction, but compromises mammary bud growth, as well as TEB formation, ductal outgrowth and branching during puberty. We further show that loss of Fgf20 delays formation of Eda-induced supernumerary mammary buds and normalizes the embryonic and postnatal hyperbranching phenotype of Eda overexpressing mice. These findings identify a hitherto unknown function for Fgf20 in mammary budding and branching morphogenesis.Peer reviewe
Embryonic mammary signature subsets are activated in Brca1-/- and basal-like breast cancers
Introduction: Cancer is often suggested to result from development gone awry. Links between normal embryonic
development and cancer biology have been postulated, but no defined genetic basis has been established. We
recently published the first transcriptomic analysis of embryonic mammary cell populations. Embryonic mammary
epithelial cells are an immature progenitor cell population, lacking differentiation markers, which is reflected in
their very distinct genetic profiles when compared with those of their postnatal descendents.
Methods: We defined an embryonic mammary epithelial signature that incorporates the most highly expressed
genes from embryonic mammary epithelium when compared with the postnatal mammary epithelial cells. We
looked for activation of the embryonic mammary epithelial signature in mouse mammary tumors that formed in
mice in which Brca1 had been conditionally deleted from the mammary epithelium and in human breast cancers
to determine whether any genetic links exist between embryonic mammary cells and breast cancers.
Results: Small subsets of the embryonic mammary epithelial signature were consistently activated in mouse
Brca1-/- tumors and human basal-like breast cancers, which encoded predominantly transcriptional regulators, cellcycle,
and actin cytoskeleton components. Other embryonic gene subsets were found activated in non-basal-like
tumor subtypes and repressed in basal-like tumors, including regulators of neuronal differentiation, transcription,
and cell biosynthesis. Several embryonic genes showed significant upregulation in estrogen receptor (ER)-negative,
progesterone receptor (PR)-negative, and/or grade 3 breast cancers. Among them, the transcription factor, SOX11, a
progenitor cell and lineage regulator of nonmammary cell types, is found highly expressed in some Brca1-/-
mammary tumors. By using RNA interference to silence SOX11 expression in breast cancer cells, we found evidence
that SOX11 regulates breast cancer cell proliferation and cell survival.
Conclusions: Specific subsets of embryonic mammary genes, rather than the entire embryonic development
transcriptomic program, are activated in tumorigenesis. Genes involved in embryonic mammary development are
consistently upregulated in some breast cancers and warrant further investigation, potentially in drug-discovery
research endeavors
Mechanical tuning of the evaporation rate of liquid on crossed fibers
We investigate experimentally the drying of a small volume of perfectly
wetting liquid on two crossed fibers. We characterize the drying dynamics for
the three liquid morphologies that are encountered in this geometry: drop,
column and a mixed morphology, in which a drop and a column coexist. For each
morphology, we rationalize our findings with theoretical models that capture
the drying kinetics. We find that the evaporation rate depends significantly on
the liquid morphology and that the drying of liquid column is faster than the
evaporation of the drop and the mixed morphology for a given liquid volume.
Finally, we illustrate that shearing a network of fibers reduces the angle
between them, changes the morphology towards the column state, and so enhances
the drying rate of a volatile liquid deposited on it
Transcriptome analysis of embryonic mammary cells reveals insights into mammary lineage establishment
Introduction: The mammary primordium forms during embryogenesis as a result of inductive interactions between its constitutive tissues, the mesenchyme and epithelium, and represents the earliest evidence of commitment to the mammary lineage. Previous studies of embryonic mouse mammary epithelium indicated that, by mid-gestation, these cells are determined to a mammary cell fate and that a stem cell population has been delimited. Mammary mesenchyme can induce mammary development from simple epithelium even across species and classes, and can partially restore features of differentiated tissue to mouse mammary tumours in co-culture experiments. Despite these exciting properties, the molecular identity of embryonic mammary cells remains to be fully characterised.
Methods: Here, we define the transcriptome of the mammary primordium and the two distinct cellular compartments that comprise it, the mammary primordial bud epithelium and mammary mesenchyme. Pathway and network analysis was performed and comparisons of embryonic mammary gene expression profiles to those of both postnatal mouse and human mammary epithelial cell sub-populations and stroma were made.
Results: Several of the genes we have detected in our embryonic mammary cell signatures were previously shown to regulate mammary cell fate and development, but we also identified a large number of novel candidates. Additionally, we determined genes that were expressed by both embryonic and postnatal mammary cells, which represent candidate regulators of mammary cell fate, differentiation and progenitor cell function that could signal from mammary lineage inception during embryogenesis through postnatal development. Comparison of embryonic mammary cell signatures with those of human breast cells identified potential regulators of mammary progenitor cell functions conserved across species.
Conclusions: These results provide new insights into genetic regulatory mechanisms of mammary development, particularly identification of novel potential regulators of mammary fate and mesenchymal-epithelial cross-talk. Since cancers may represent diseases of mesenchymal-epithelial communications, we anticipate these results will provide foundations for further studies into the fundamental links between developmental, stem cell and breast cancer biology
Diagnostic yield of renal biopsies: a retrospective single center review
<p>Abstract</p> <p>Background</p> <p>Previous studies have examined the spectrum of diseases identified with a kidney biopsy and the complications of the procedure. However, few studies have examined the utility of the test to clarify the diagnosis and guide treatment of pediatric patients. This retrospective, single-center chart review was performed to test the hypothesis that at least 80% of native kidney biopsies provide clinically valuable information that rationally guides diagnosis and patient management.</p> <p>Methods</p> <p>200 biopsies performed between January 1, 2000 and June 30, 2008 were reviewed. A scheme composed of six categories was devised to classify the utility of each kidney biopsy.</p> <p>Results</p> <p>196 complete case files were available for review. Twenty-four (12.2%) biopsies did not shed light on the diagnosis and were unhelpful in patient management â 21 biopsies (10.7%) were non-diagnostic and 3 (1.5%) failed to yield enough tissue for examination. The number of unhelpful biopsies did not cluster in any specific disease entity.</p> <p>Conclusion</p> <p>Our findings provide guidance to nephrologists about the total risk of a kidney biopsy, including uninformative results, when seeking informed consent for the procedure. The results suggest an appropriate balance has been reached which maximizes the use of kidney biopsies while minimizing the risk of this invasive procedure (word count: 202).</p
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