95 research outputs found
Abnormal Cystatin C Levels in Two Patients with Bardet-Biedl Syndrome
Bardet-Biedl syndrome (BBS) is an autosomal recessive disorder characterized by central obesity, mental impairment, rod-cone dystrophy, polydactyly, hypogonadism in males, and renal abnormalities. The causative genes have been identified as BBS1-14. In the Western countries, the prevalence of this disease ranges from 1/13,500 to 1/160,000, while only a few Japanese patients have been reported in the English-language literature. The incidence of renal dysfunction or anomalies in previous reports varies considerably ranging from βΌ20% to universal occurrence. We here report that two Japanese patients who had BBS with normal BUN and creatinine levels had elevated levels of cystatin C, a sensitive marker of glomerular filtration rate. A urine albumin level increased only in the elder patient. Thus, cystatin C may be useful for detecting renal abnormalities in patients with an apparent normal renal function. Because this disease is diagnosed by accumulation of symptoms, such a sensitive marker might help early diagnosis of BBS
Immobilization of fibronectin in chitosan substrates improves cell adhesion and proliferation
Covalent grafting of biomolecules is a strategy to improve the biocompatibility and bioactivity of
materials. However, it is critical to maintain the biological activity of the biomolecule upon its
attachment to the surface. In the present study we compared the biological properties of chitosan,
in which the surface was enriched with fibronectin (Fn), using two methodologies: chemical
immobilization, using a water-soluble carbodiimide; and simple adsorption. X-ray photoelectron
spectroscopy studies confirmed the successful immobilization of Fn onto modifiedmembranes. SaOs-
2 cells were seeded onto these surfaces to assess the biological consequences of such modifications.
The presence of Fn stimulated cell adhesion on chitosan. It was found that after 7 days of culture
in the presence of covalently attached Fn, the cells are confluent; significantly fewer cells were
detected in unmodified film and in film with adsorbed Fn. This result is consistent with the fact
that considerable desorption of Fn from chitosan takes place within 24 h in culture medium. This
study showed that Fn may be easily covalently attached onto chitosan substrates, improving the
biological performance of the material. The technique could find applications in tissue-engineering
strategies, as the surface modification of chitosan-based substrates could be carried out in more
complex geometries, such as in scaffolds or particles
Control of Cortical Axon Elongation by a GABA-Driven Ca<sup style="margin: 0px; padding: 0px; border: 0px; outline-style: none; font-weight: inherit; font-style: inherit; font-size: 0.85em; font-family: inherit; line-height: 0; text-align: inherit; vertical-align: super;">2+/Calmodulin-Dependent Protein Kinase Cascade</sup>
Ca(2+) signaling plays important roles during both axonal and dendritic growth. Yet, whether and how Ca(2+) rises may trigger and contribute to the development of long range cortical connections remains largely unknown. Here we demonstrate that two separate limbs of CaMK kinase (CaMKK) - CaMKI cascades, CaMKK-CaMKIΞ± and CaMKK-CaMKIΞ³, critically coordinate axonal and dendritic morphogenesis of cortical neurons, respectively. The axon-specific morphological phenotype required a diffuse cytoplasmic localization and a strikingly Ξ±-isoform-specific kinase activity of CaMKI. Unexpectedly, treatment with muscimol, a GABA(A) receptor agonist, selectively stimulated elongation of axons but not of dendrites, and the CaMKK-CaMKIΞ± cascade critically mediated this axonogenic effect. Consistent with these findings, during early brain development, in vivo knockdown of CaMKIΞ± significantly impaired the terminal axonal extension, and thereby perturbed the refinement of the interhemispheric callosal projections into the contralateral cortices. Our findings thus indicate a novel role for the GABA-driven CaMKK-CaMKIΞ± cascade as a mechanism critical for accurate cortical axon pathfinding, an essential process which may contribute to fine-tuning the formation of interhemispheric connectivity during the perinatal development of the central nervous system
Interplay between Structure and Dynamics in Chitosan Films Investigated with Solid-State NMR, Dynamic Mechanical Analysis, and X-ray Diffraction
Modern solid-state NMR techniques, combined with X-ray diffraction, revealed the molecular origin of the difference in mechanical properties of self-associated chitosan films. Films cast from acidic aqueous solutions were compared before and after neutralization, and the role of the counterion (acetate vs Clβ») was investigated. There is a competition between local structure and long-range order. Hydrogen bonding gives good mechanical strength to neutralized films, which lack long-range organization. The long-range structure is better defined in films cast from acidic solutions in which strong electrostatic interactions cause rotational distortion around the chitosan chains. Plasticization by acetate counterions enhances long-range molecular organization and film flexibility. In contrast, Clβ» counterions act as a defect and impair the long-range organization by immobilizing hydration water. Molecular motion and proton exchange are restricted, resulting in brittle films despite the high moisture content
Ex Vivo Expansion of Human CD8+ T Cells Using Autologous CD4+ T Cell Help
Background: Using in vivo mouse models, the mechanisms of CD4+ T cell help have been intensively investigated. However, a mechanistic analysis of human CD4+ T cell help is largely lacking. Our goal was to elucidate the mechanisms of human CD4+ T cell help of CD8+ T cell proliferation using a novel in vitro model. Methods/Principal Findings: We developed a genetically engineered novel human cell-based artificial APC, aAPC/mOKT3, which expresses a membranous form of the anti-CD3 monoclonal antibody OKT3 as well as other immune accessory molecules. Without requiring the addition of allogeneic feeder cells, aAPC/mOKT3 enabled the expansion of both peripheral and tumor-infiltrating T cells, regardless of HLA-restriction. Stimulation with aAPC/mOKT3 did not expand Foxp3+ regulatory T cells, and expanded tumor infiltrating lymphocytes predominantly secreted Th1-type cytokines, interferon-Ξ³ and IL-2. In this aAPC-based system, the presence of autologous CD4+ T cells was associated with significantly improved CD8+ T cell expansion in vitro. The CD4+ T cell derived cytokines IL-2 and IL-21 were necessary but not sufficient for this effect. However, CD4+ T cell help of CD8+ T cell proliferation was partially recapitulated by both adding IL-2/IL-21 and by upregulation of IL-21 receptor on CD8+ T cells. Conclusions: We have developed an in vitro model that advances our understanding of the immunobiology of human CD4+ T cell help of CD8+ T cells. Our data suggests that human CD4+ T cell help can be leveraged to expand CD8+ T cells in vitro
Currentodensitogram of SAM virtual sensors compared with simultaneously recorded ECoG
Introduction Equivalent current dipole (ECD) analysis for magnetoencephalogram (MEG) has been useful in screening the localization of the epileptogenic zone, even though MEG was recorded in the interictal period [1] [2]. However, it requires several mathematical restrictions and often fails to estimate confidential current sources. Therefore the epileptogenic area derived from the ECD analysis might include certain extent of bias. Recently synthetic aperture magnetometry (SAM) was developed [3] using a beamformer method. It enables to measure the entire sequence of current density in the focused small regions of the brain as if an electrical sensors were placed (virtual sensor, VS) We applied SAM-VS method to elucidate the origin of the epileptic discharge and compared it with simultaneously recorded electrocorticogram (ECoG). 2 Methods A 11-year-old girl with intractable seizure was studied. MRI disclosed pachygyri and atrophy of the left temporal lobe with a small anterior mes
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