1,720,982 research outputs found
Parathyroid Hormone (PTH (1-34)) and Parathyroid Hormone-Related Protein (PTHrP (1-34) promote reversion of hypertrophic chondrocytes to a prehypertrophic proliferating phenotype and prevent terminal differentiation of osteoblast-lioke cells.
Noise enhanced control of multistability
We focus into the development of an efficient method to control multistable systems in the presence of noise. The method is based on the addition of an external control force in the form of a slow harmonic modulation with properly chosen frequency and amplitude. Although noise is usually a non desirable condition, it has been recently demostrated that in coupled systems cooperative effects of the periodic force and noise are produced. This enhancement phenomena in the response of the deterministic equations is interpreted as stochastic resonance. Our main purpose is to study deterministic resonances between the different solutions of the multistable system and the external modulation. Then, all efforts will concentrate in the enhancement of the control method produced by noise
The antibody to the 70-kd antigen in chronic ulcerative stomatitis and lichen planus.
Background Antibodies to stratified epithelia characterize chronic ulcerative stomatitis, an entity that very closely resembles erosive lichen planus both clinically and histologically. These antibodies are directed against a 70-kd antigen. Objective Our aim was to verify whether antibodies to stratified epithelia are present in patients with common lichen planus. Patients and methods One hundred thirty-eight patients with various forms of lichen planus were studied. Indirect immunofluorescence was performed on both monkey esophagus and HEp2-2000 cells. Immunoblotting was done with cultured keratinocytes used as the source antigen. Results Nineteen patients had antibodies to stratified epithelia (in 9 directed against an antigen of 70 kd). Forty-eight patients had circulating antibodies detected by indirect immunofluorescence on both monkey esophagus and HEp2-2000 cells (in 7 directed against an antigen of 70 kd). Indirect immunofluorescence was positive only on HEp2-2000 cells in 21 patients. Indirect immunofluorescence was negative in 50 patients on both HEp2-2000 cells and monkey esophagus. None of the last 71 patients had antibodies directed to an antigen of 70 kd. Limitations This is a serological study; results from direct immunofluorescence studies would be interesting. Conclusion Antibodies to stratified epithelia directed to an antigen of 70 kd are not exclusive to chronic ulcerative stomatitis, but are also present in some patients with lichen planus
A chondrogenesis-related lipocalin cluster includes a third new gene, CAL gamma
We have previously reported the modulation, during chondrogenesis and/or inflammation, of two chicken genes laying in the same genomic locus and coding for two polypeptides of the lipocalin protein family, the extracellular fatty acid binding protein (ExFABP) and the chondrogenesis associated lipocalin beta (CALbeta). A third gene, located within the same cluster and coding for a new lipocalin, CALgamma, has been identified and is here characterized. Tissue distribution analyzed by real-time quantitative reverse transcriptase-polymerase chain reaction in chicken embryos shows a ubiquitous expression with predominant levels of mRNA transcripts in the liver and the brain. In the developing tibia, a high expression of CALgamma mRNA was evidenced by in situ hybridization within the pre-hypertrophic and the hypertrophic zones of the bone-forming cartilage. In agreement, dedifferentiated chondrocytes in vitro express the transcripts to the highest level when they re-differentiate reaching hypertrophy. Such peculiar developmental pattern of expression that is analogous to those already described for Ex-FABP and CALbeta suggests that all three proteins may act synergistically in the process of endochondral bone formation
CAL b, a novel lipocalin associated with chondrogenesis and inflammation
We have previously demonstrated the association of the chicken lipocalin Ex-FABP with cartilage formation and inflammatory responses as a marker of these processes (Descalzi Cancedda et al., Biochim. Biophys. Acta 1482, 127-135, 2000). Here we report the isolation and characterisation of a new lipocalin gene laying upstream the Ex-FABP, thus representing the second member of a possible genomic cluster. This gene contains an open reading frame coding for a polypeptide of about 19 kDa. The amino-acid sequence revealed a conserved lipocalin secondary structure. Tissue distribution of the protein in developing embryos showed a preferential expression in the heart although mRNA transcripts could be detected also in muscle, lung and liver
Ex-FABP, extracellular fatty acid binding protein, is a stress lipocalin expressed during chicken embryo development.
Avidin expression during chick chondrocyte and myoblast development "in vitro" and "in vivo": regulation of cell proliferation.
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