130 research outputs found
A loss of c-kit expression is associated with an advanced stage and poor prognosis in breast cancer
To evaluate the c-kit expression in breast cancer, 217 invasive ductal carcinomas of the breast were immunohistochemically stained for c-kit protein. The c-kit expression was positive in 59 (27%) of 217 tumours, while the c-kit expression was negative in 158 (73%) of 217 tumours. There was a significant correlation between a negative expression of the c-kit protein and lymph node metastasis (P<0.0001), and the incidence of a negative expression of the c-kit protein increased as the number of the metastatic lymph nodes increased (P=0.0003). The c-kit expression did not significantly correlate with the tumour size, nuclear grade, oestrogen receptor status, MIB-1 counts and p53 protein expression. A univariate analysis indicated the patients with the negative c-kit expression to have a worse disease-free survival (DFS) than those with the positive c-kit expression (P=0.0041), while a multivariate analysis determined lymph node metastases and the MIB-1 counts to be independently significant factors for DFS. In conclusion, a loss of the c-kit expression was found in about three-fourth of invasive ductal carcinoma of the breast and was associated with lymph node metastases. The prognostic implications of the c-kit expression seem to be due to fact that a loss of the c-kit expression is associated with an advanced stage of breast cancer
Hair follicle epidermal stem cells define a niche for tactile sensation
The heterogeneity and compartmentalization of stem cells is a common principle in many epithelia, and is known to function in epithelial maintenance, but its other physiological roles remain elusive. Here we show transcriptional and anatomical contributions of compartmentalized epidermal stem cells in tactile sensory unit formation in the mouse hair follicle. Epidermal stem cells in the follicle upper-bulge, where mechanosensory lanceolate complexes innervate, express a unique set of extracellular matrix (ECM) and neurogenesis-related genes. These epidermal stem cells deposit an ECM protein called EGFL6 into the collar matrix, a novel ECM that tightly ensheathes lanceolate complexes. EGFL6 is required for the proper patterning, touch responses, and αv integrin-enrichment of lanceolate complexes. By maintaining a quiescent original epidermal stem cell niche, the old bulge, epidermal stem cells provide anatomically stable follicle–lanceolate complex interfaces, irrespective of the stage of follicle regeneration cycle. Thus, compartmentalized epidermal stem cells provide a niche linking the hair follicle and the nervous system throughout the hair cycle
Vasculature-driven stem cell population coordinates tissue scaling in dynamic organs
Stem cell (SC) proliferation and differentiation organize tissue homeostasis. However, how SCs regulate coordinate tissue scaling in dynamic organs remain unknown. Here, we delineate SC regulations in dynamic skin. We found that interfollicular epidermal SCs (IFESCs) shape basal epidermal proliferating clusters (EPCs) in expanding abdominal epidermis of pregnant mice and proliferating plantar epidermis. EPCs consist of IFESC-derived Tbx3⁺–basal cells (Tbx3⁺-BCs) and their neighboring cells where Adam8–extracellular signal–regulated kinase signaling is activated. Clonal lineage tracing revealed that Tbx3⁺-BC clones emerge in the abdominal epidermis during pregnancy, followed by differentiation after parturition. In the plantar epidermis, Tbx3⁺-BCs are sustained as long-lived SCs to maintain EPCs invariably. We showed that Tbx3⁺-BCs are vasculature-dependent IFESCs and identified mechanical stretch as an external cue for the vasculature-driven EPC formation. Our results uncover vasculature-mediated IFESC regulations, which explain how the epidermis adjusts its size in orchestration with dermal constituents in dynamic skin
Anti-N-Methyl-D-Aspartate Receptor Encephalitis in Psychiatry
Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a recently-discovered autoimmune disorder in which antibodies target NMDAR in the brain. The number of reported cases of anti-NMDAR encephalitis has increased rapidly. Anti-NMDAR encephalitis can be mistakenly diagnosed as psychiatric disorders because many patients present with prominent psychiatric symptoms and visit psychiatric institutions first. Thus, psychiatrists should cultivate a better understanding of anti-NMDAR encephalitis. In this review, we present the mechanisms, epidemiology, symptoms and clinical course, diagnostic tests, treatment and outcomes of patients with anti-NMDAR encephalitis. Furthermore, we discuss the diversity of clinical spectra of anti-NMDAR encephalitis, and demonstrate a differential diagnosis of psychiatric disease from the perspective of psychiatry
Searching for realistic 4d string models with a Pati-Salam symmetry -- Orbifold grand unified theories from heterotic string compactification on a Z6 orbifold
Motivated by orbifold grand unified theories, we construct a class of
three-family Pati-Salam models in a Z6 abelian symmetric orbifold with two
discrete Wilson lines. These models have marked differences from
previously-constructed three-family models in prime-order orbifolds. In the
limit where one of the six compactified dimensions (which lies in a Z2
sub-orbifold) is large compared to the string length scale, our models
reproduce the supersymmetry and gauge symmetry breaking pattern of 5d orbifold
grand unified theories on an S1/Z2 orbicircle. We find a horizontal 2+1
splitting in the chiral matter spectra -- 2 families of matter are localized on
the Z2 orbifold fixed points, and 1 family propagates in the 5d bulk -- and
identify them as the first-two and third families. Remarkably, the first two
families enjoy a non-abelian dihedral D4 family symmetry, due to the geometric
setup of the compactified space. In all our models there are always some color
triplets, i.e. (6,1,1) representations of the Pati-Salam group, survive
orbifold projections. They could be utilized to spontaneously break the
Pati-Salam symmetry to that of the Standard Model. One model, with a 5d E6
symmetry, may give rise to interesting low energy phenomenology. We study gauge
coupling unification, allowed Yukawa couplings and some of their
phenomenological consequences. The E6 model has a renormalizable Yukawa
coupling only for the third family. It predicts a gauge-Yukawa unification
relation at the 5d compactification scale, and is capable of generating
reasonable quark/lepton masses and mixings. Potential problems are also
addressed, they may point to the direction for refining our models.Comment: 58 pages, 5 figures, 4 tables, revtex4 with ams fonts. Version to
appear in NP
Pathogenic variants in THSD4, encoding the ADAMTS-like 6 protein, predispose to inherited thoracic aortic aneurysm
Purpose Thoracic aortic aneurysm and dissection (TAAD) is a life-threatening disease with often unrecognized inherited forms. We sought to identify novel pathogenic variants associated with autosomal dominant inheritance of TAAD. Methods We analyzed exome sequencing data from 35 French TAAD families and performed next-generation sequencing capture panel of genes in 1114 unrelated TAAD patients. Functional effects of pathogenic variants identified were validated in cell, tissue, and mouse models. Results We identified five functional variants inTHSD4of which two heterozygous variants lead to a premature termination codon.THSD4encodes ADAMTSL6 (member of the ADAMTS/L superfamily), a microfibril-associated protein that promotes fibrillin-1 matrix assembly. TheTHSD4variants studied lead to haploinsufficiency or impaired assembly of fibrillin-1 microfibrils.Thsd4(+/-)mice showed progressive dilation of the thoracic aorta. Histologic examination of aortic samples from a patient carrying aTHSD4variant and fromThsd4(+/-)mice, revealed typical medial degeneration and diffuse disruption of extracellular matrix. Conclusion These findings highlight the role of ADAMTSL6 in aortic physiology and TAAD pathogenesis. They will improve TAAD management and help develop new targeted therapies
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