Whole organ culture of the intervertebral disc (IVD) preserves the native extracellular matrix, cell phenotypes, and cellular-matrix...
Project 1 work was focused on using multi-plexed assays for high-content imaging and high-throughput transcriptomic analyses using iCell cardiomyocyte organotypic culture model and other cell types derived from iPS cells. We have completed testing 140 compounds selected in consultation with FDA, NTP and EPA-NCCT in a population-based in vitro iPSC-derived cell model with iCell cardiomyocytes from 43 normal donors. Several manuscripts detailing the outcomes have been published or are in submission. Using these data from this in vitro screening, and data from human clinical trials, we demonstrated that in vitro human iPSC-derived cardiomyocyte model accurately predicts clinical concentration-QTc relationships. This finding confirms our central hypothesis that human induced pluripotent stem cell (iPSC)-derived cardiomyocyte cultures constitute an effective organotypic culture model for predictive toxicity screening. We also showed that iPSC-derived cardiomyocytes are a highly reproducible in vitro ...
Organ Culture Studies of Murine Oral Mucosa with Particular Emphasis on Epithelial Proliferation and Connective Tissue Mast Cells in the Presence and Absence of Oestrogen ...
НИИ атеросклероза: научные исследования, публикации сотрудников института (abstracts, full-text.), дискуссионный клуб, посвященный вопросам механизмов атерогенеза.
The liver, the largest organ of the human body, is a multifunctional organ with various metabolic activities that plays a fundamental role in maintaining the body and in sustaining life. Although the liver has great regenerative capacity and recovery, the damage caused by chronic diseases such as cancer or viral infections can lead to permanent loss of liver function. Studies on the mechanism of liver disease, have focused on the selection of cell and tissue culture techniques, including strategies based on |i|in vitro|/i| models. The organ culture is a promising tool for the study of liver diseases, because it can mimic the complex of the microenvironment |i|in vivo|/i| using a three-dimensional model of human liver tissue. These models allow a better study of the specific functions of the liver. In this context, we have analyzed the development of a hepatocarcinoma, obtained by inoculating a murine hepatocarcinoma cell line, Hepa 1/A1s, in the liver of 10 mice of the strain C57BL / 6. After 20 days
All imaging and electrophysiology measurements were performed in Tyrodes buffer containing the following (in mm): 125 NaCl, 2.5 KCl, 3 CaCl2, 1 MgCl2, 15 HEPES, and 30 glucose, pH 7.3. For HEK cell measurements, 2-aminoethoxydiphenyl borate (100 μm; Sigma-Aldrich) was added to block endogenous gap junctions. Measurements at 34°C were performed by perfusing in Tyrodes buffer at 1 ml/min while maintaining elevated temperature with an inline heater (Warner Instruments) and an objective heater (Bioptechs).. Filamented glass micropipettes (WPI) were pulled to a tip resistance of 4-8 MΩ and filled with internal solution containing the following (in mm): 125 potassium gluconate, 8 NaCl, 0.6 MgCl2, 0.1 CaCl2, 1 EGTA, 10 HEPES, 4 Mg-ATP, and 0.4 Na-GTP, pH 7.3, adjusted to 295 mOsm with sucrose. Pipettes were positioned with a Sutter Instruments MP285 manipulator. Whole-cell, voltage and current-clamp recordings were acquired using an Axopatch 700B amplifier (Molecular Devices), filtered at 2 kHz ...
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Organotypic slice cultures are the in vitro method of choice for applications requiring long‐term survival of the preparation and a high degree of cellular differentiation and organization resembling that of the original tissue
We established a serum-free organ culture system of isolated single vibrissa rudiments taken from embryonic day 13 mice. This… Expand ...
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Pancreatic cancer is characterized by an intense stromal reaction. Reproducible three-dimensional in vitro systems for exploring interactions of the stroma with pancreatic cancer cells have not previously been available, prompting us to develop such a model. Cancer cells were grown on collagen/Matri …
Faramarz Dehghani is the author of these articles in the Journal of Visualized Experiments: Coculture System with an Organotypic Brain Slice and 3D Spheroid of Carcinoma Cells, Organotypic Hippocampal Slice Cultures As a Model to Study Neuroprotection and Invasiveness of Tumor Cells
The Division is working on the characterization of the genetic response of organisms and their cells to external signals (growth factors, inflammation-related cytokines, carcinogens and tumor promoters), employing genetically modified mouse models (which replicate features of human diseases) and cell- and organ cultures derived thereof. We want to define and characterize altered gene functions, which result in imbalanced signaling pathways and downstream genetic programs that form the basis for acquired capabilities of uncontrolled cell growth, evasion of apoptosis, sustained angiogenesis and, finally, enhanced tissue invasion and metastasis. To date, we have applied genetically modified animal models, in vitro organ systems, and genome-wide expression analyses in order to decipher the individual functions of AP-1 subunits. Our study of individual AP-1 subunits with regard to their regulation, as well as the identification of distinct targets genes and genetic programs critically involved in ...
As many of you know, my experimental background is in hippocampal culture. Recently, I attended a hippocampal slice culture workshop given by members of the Hayashi lab here at MIT. I never really knew too much about the pros and cons of slice culture. After seeing the technique, I wrote up a little summary of…
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TY - JOUR. T1 - A novel organ culture model of a joint for the evaluation of static and dynamic load on articular cartilage. AU - Lin, Y. C.. AU - Hall, A. C.. AU - Simpson, A. H.R.W.. PY - 2018/3/1. Y1 - 2018/3/1. N2 - Objectives: The purpose of this study was to create a novel ex vivo organ culture model for evaluating the effects of static and dynamic load on cartilage. Methods: The metatarsophalangeal joints of 12 fresh cadaveric bovine feet were skinned and dissected aseptically, and cultured for up to four weeks. Dynamic movement was applied using a custom-made machine on six joints, with the others cultured under static conditions. Chondrocyte viability and matrix glycosaminoglycan (GAG) content were evaluated by the cell viability probes, 5-chloromethylfluorescein diacetate (CMFDA) and propidium iodide (PI), and dimethylmethylene blue (DMMB) assay, respectively. Results: Chondrocyte viability in the static model decreased significantly from 89.9% (sd 2.5%) (Day 0) to 66.5% (sd 13.1%) ...
TY - JOUR. T1 - Dentate development in organotypic hippocampal slice cultures from p35 knockout mice. AU - Wenzel, H. Jürgen. AU - Tamse, Catherine T.. AU - Schwartzkroin, Philip A. PY - 2006/12. Y1 - 2006/12. N2 - Abnormal brain development, induced by genetic influences or resulting from a perinatal trauma, has been recognized as a cause of seizure disorders. To understand how and when these structural abnormalities form, and how they are involved in epileptogenesis, it is important to generate and investigate animal models. We have studied one such model, a mouse in which deletion of the p35 gene (p35-/-) gives rise to both structural disorganization and seizure-like function. We now report that aberrant dentate development can be recognized in the organotypic hippocampal slice culture preparation generated from p35-/- mouse pups. In these p35-/- cultures, an abnormally high proportion of dentate granule cells migrates into the hilus and molecular layer, and develops aberrant dendritic and ...
Corning Matrigel Matrix for Organoid Culture is a solubilized basement membrane preparation that has been optimized for organoid culture. Verified to support both mouse and human organoid growth and differentiation from healthy and/or diseased tissue, each lot has a specific elastic modulus value indicating the stiffness of the gel formed and is qualified to form stable 3D domes commonly used in organoid culture protocols. Available in 10mL LDEV-free, Phenol Red-free format. Corning Matrigel Matrix for Organoid culture is extracted from the Engelbreth-Holm-Swarm (EHS) mouse sarcoma, a tumor rich in extracellular matrix proteins, including Laminin (a major component), Collagen IV, heparan sulfate proteoglycans, entactin/nidogen, and a number of growth factors. Quality • Tested for ability to form and maintain stable 3D domes/droplets on multi-well plates. • Elastic Modulus (matrix stiffness) measured using a rheometer. • Protein concentrations determined by Lowry method • Mouse colonies
article{1fdd16d8-cade-46c6-b3bf-0719173f035c, abstract = {Both brain-derived neurotrophic factor (BDNF) and the serotonin receptor 2A (5-HT2A) have been related to depression pathology. Specific 5-HT2A receptor changes seen in BDNF conditional mutant mice suggest that BDNF regulates the 5-HT2A receptor level. Here we show a direct effect of BDNF on 5-HT2A receptor protein levels in primary hippocampal neuronal and mature hippocampal organotypic cultures exposed to different BDNF concentrations for either 1, 3, 5 or 7 days. In vivo effects of BDNF on hippocampal 5-HT2A receptor levels were further corroborated in (BDNF +/-) mice with reduced BDNF levels. In primary neuronal cultures, 7 days exposure to 25 and 50 ng/mL BDNF resulted in downregulation of 5-HT2A, but not of 5-HT1A, receptor protein levels. The BDNF-associated downregulation of 5-HT2A receptor levels was also observed in mature hippocampal organotypic cultures, excluding confounding effects of BDNF on immature tissue. BDNF +/- mice ...
The BH3 interacting-domain death agonist (BID) is a pro-apoptotic protein involved in death receptor-induced and mitochondria-mediated apoptosis. Recently, it has also been suggested that BID is involved in the regulation of inflammatory responses in the central nervous system. We found that BID deficiency protected organotypic hippocampal slice cultures in vitro from neuronal injury induced by oxygen-glucose deprivation. In vivo, BID-knockout (KO) mice and WT mice were subjected to 60 minutes of transient middle cerebral artery occlusion to induce focal cerebral ischemia, and allowed to recover for 24 hours. Infarct volumes and functional outcome were assessed and the inflammatory response was evaluated using immunofluorescence, Western blotting, quantitative PCR and Mesoscale multiplex analysis. We observed no difference in the infarct volume or neurological outcome between BID-KO and WT mice. The inflammatory response was reduced by BID deficiency as indicated by a change in microglial/leukocyte
Organ culture is a development from tissue culture methods of research, the organ culture is able to accurately model functions of an organ in various states and conditions by the use of the actual in vitro organ itself. Parts of an organ or a whole organ can be cultured in vitro. The main objective is to maintain the architecture of the tissue and direct it towards normal development. In this technique, it is essential that the tissue is never disrupted or damaged. It thus requires careful handling. The media used for a growing organ culture are generally the same as those used for tissue culture. The techniques for organ culture can be classified into (i) those employing a solid medium and (ii) those employing liquid medium. In April 2006, scientists reported a successful trial of seven bladders grown in-vitro and given to humans. A bladder has been cultured by Anthony Atala of the Wake Forest Institute for Regenerative Medicine in Winston-Salem, North Carolina. A jawbone has been cultured at ...
Understanding how probiotics, prebiotics or postbiotics work in preclinical models that resemble the human situation can allow a rational choice of the different strains or compounds for clinical and/or commercial use according to the pathological condition to which they are targeted. Indeed, we recently demonstrated that different Lactobacilli species can be classified as either immunogenic or tolerogenic.17 Testing of different probiotics has often been performed on isolated immune cells or peripheral blood mononuclear cells.21 However, particularly in the gut, the interaction of bacteria with the mucosa is an unusually complex event requiring attachment or degradation of mucus, competition with the microbiota and resistance to antimicrobial peptides.13 In addition, the function of immune cells is influenced by the local microenvironment and this is required to preserve intestinal homeostasis.4-22 Indeed, we have shown that signals from intestinal epithelial cells can drive the ...
Studies of the most immature T cell progenitors in the human thymus have been hampered by the lack of markers and assays that define these cells. In this report we used a novel human fetal thymic organ culture system to determine the potential of T cell precursors isolated from human postnatal thymus, to differentiate into CD3+ thymocytes, and to investigate early stages of human T cell development. It was found that thymocytes that lack the markers CD3, CD4, and CD8 (triple negative [TN]) can differentiate in an allogeneic organotypic thymic culture. The capacity of TN thymocytes to differentiate was exclusively confined to the CD34+ population. CD34- TN thymocytes failed to differentiate in this system. In contrast, cloned lines of CD3- thymocytes could only be established from CD34- TN thymocytes. Five subsets of CD3- thymocytes were found with the following phenotype: CD1-TN, CD1+TN, CD1+CD4+CD8-, CD1+CD4+CD8 alpha+ beta-, and CD1+CD4+CD8 alpha beta+. These subpopulations expressed ...
A novel in vitro culture system of organotypic human skin explants interfacing with external fixator pins is presented. The system was used to observe changes in skin morphology on the skin at the pin
Indirect evidence suggests that stimulation of α1-adrenergic receptors (ARs) increases smooth muscle cell (SMC) growth in the growing and adult artery and worsens atherosclerosis and restenosis after balloon injury. In support of a direct adrenergic effect, we have previously shown that α1D-AR stimulation induces SMC hypertrophy in cell and vessel organ culture. Because interactions between α1-ARs and peptide growth factors may be important in normal and pathological SMC growth, herein we examined regulation of α1D-AR expression by growth factors. Platelet-derived growth factor (PDGF)-BB dose- and time-dependently lowered α1D mRNA in cultured quiescent SMCs (e.g., 58% inhibition at 20 ng/ml, 24 h, p , .05), whereas other α1-AR transcripts were unaffected. This same selective effect was seen in the medial layer of aorta in ex vivo organ culture. However, PDGF-AA, insulin-like growth factor-1, insulin, epidermal growth factor, endothelin, histamine, and serotonin had no effect, whereas ...
The processes responsible for epithelial spreading during wound healing and embryonic morphogenesis were investigated in an organ culture model in which an epithelial tissue (chick embryo pigmented retinal epithelium) spread over the surface of an aggregate of mesenchyme cells (chick embryo cardiac mesenchyme). The heart mesenchyme aggregate is differentiated into a core of stellate cells associated with a fibronectin-poor matrix surrounded by a cortical zone, 2-5 cells in thickness, of flattened cells embedded in a fibronectin-rich extracellular matrix. Envelopment of the mesenchyme aggregate is accompanied by a movement of the cells and the fibronectin-rich extracellular matrix of the cortex over the core tissue in advance of the spreading pigmented retina tissue. Three distinct processes were identified as contributing to epithelial spreading in this system: (1) active migration of the pigmented retinal epithelium; (2) active contraction of the cortical cells of the mesenchyme aggregate to ...
Re‐formation or preservation of functional, electrically active neural networks has been proffered as one of the goals of stem cell-mediated neural therapeutics
The aim in developing this approach to the study of implantation has been to establish a method which will permit the investigation of the process extracorporeally, thus providing conditions that are more readily controllable than those obtainable in an experimental animal. Shaffers method of organ culture has been adapted to the needs of the present investigation and it has been found that somewhat more than half of the rabbit blastocysts, explanted on strips of endometrium and incubated on them as combined explants, became implanted within 48 to 72 h. ...
Get this from a library! Plant cell, tissue and organ culture : fundamental methods. [O L Gamborg; Gregory C Phillips;] -- A manual providing all relevant protocols for basic and applied plant cell and molecular technologies, such as histology, electron microscopy, cytology, virus diagnosis and gene transfer. Also ...
Complete cell culture medium for establishing three-dimensional (3D) intestinal organoid cultures from isolated human intestinal crypts or stem cells.
Completed, defined cell culture medium for establishing three-dimensional (3D) intestinal organoid cultures from isolated mouse intestinal crypts.
Fibroblasts transformed into induced thymic epithelial cells (iTEC) in vitro (left, iTEC shown in green). iTEC transplanted onto the mouse kidney forms an
from the top of the slice culture, with or without additional illumination from the bottom, we obtained good cellular resolution of ...
Integrated approaches using different in vitro methods in combination with bioinformatics can (i) increase the success rate and speed of drug development; (ii) improve the accuracy of toxicological risk assessment; and (iii) increase our understanding of disease. Three-dimensional (3D) cell culture models are important building blocks of this strategy which has emerged during the last years. The majority of these models are organotypic, i.e., they aim to reproduce major functions of an organ or organ system. This implies in many cases that more than one cell type forms the 3D structure, and often matrix elements play an important role. This review summarizes the state of the art concerning commonalities of the different models. For instance, the theory of mass transport/metabolite exchange in 3D systems and the special analytical requirements for test endpoints in organotypic cultures are discussed in detail. In the next part, 3D model systems for selected organs liver, lung, skin, brain are ...
Local drug delivery by coronary stents is of current research interest. Organ culture of human vascular tissue is a model of intimal hyperplasia. We report an ex vivo organ culture model of stented vessels. This allows stent-artery interactions to be studied in living tissue. The recognized anti-restenosis agent paclitaxel was chosen to test the organ culture model. Mammary artery specimens were cultured closed (i.e. without opening them flat) for 72h. Phosphocholine-coated stents, half of them loaded with the anti-restenosis drug paclitaxel, were implanted. The absorption and elution characteristics of paclitaxel were established. Artery tissue remained viable at 72h when cultured closed, despite stent implantation. Specimens developed smooth muscle cell proliferation. The stents absorbed up to 127±29μg of paclitaxel, with a biphasic elution curve. A mean of 13% of the absorbed paclitaxel remained after a 24h perfusion. In mammary artery, these paclitaxel stents reduced or abolished smooth ...
AMSBIO announces an extended and updated edition of its popular Organoid Culture Handbook. Launched at the EMBO Symposium on Organoids: Modelling Organ Development and Disease in 3D Culture, the new 24-page handbook includes valuable information about the latest available products, protocols, example results and research paper citations. Within the protocols section detailed information is provided on a general submerged method for organoid culture, crypt organoid culture techniques...
Until fairly recently very little was known about the receptors, ligands, and molecular signals necessary for thymocyte emigration. Earlier work showed that expression of the catalytic subunit of pertussis toxin in thymocytes inhibited their emigration, pointing toward the involvement of a Gαi protein-coupled receptor (31). Studies of egress from fetal thymic organ cultures suggested that CCR7 plays a role in the neonatal period (32), but in the adult, thymocytes emigrate independently of CCR7 despite having an impaired cortex-to-medulla migration (1, 2, 14). Chemorepulsion or fugetaxis has also been proposed to have a role in thymic emigration. In in vitro assays, CXCR4-expressing thymocytes move away from the thymus in a stromal cell-derived factor 1 (SDF-1)-dependent manner (33). The disruption of SDF-1/CXCR4 interactions by genetic deficiency or pharmacological antagonism with AMD3100 led to decreased migration in fetal thymic organ culture. In vivo treatment with AMD3100 in newborn mice ...
Discussion about Covid19/WORLD:6.575.000/USA:1.902.000/RIOTS ARE SUPER SPREADERS P9441/ALSO MILD LEAVES LONG-TERM ORGAN DAMAGE P9451/US CURVE P9464 [Page 9337] at the GodlikeProductions Conspiracy Forum. Our topics include Conspiracy Theory, Secret Societies, UFOs and more!
To investigate the changes in COX-2 activity and expression in bypass conduits after CABG surgery, we studied isolated segments of SV and IMA from the same patients using an organ culture system. After 2 consecutive days in culture, segments of SV and IMA released prostanoids in the order of PGE2≥prostacyclinTXA2, and these segments contained detectable COX-2 mRNA. These results are consistent with the reported high expression of prostacyclin synthase and low expression of TX synthase in vascular smooth muscle22 23 and the ability of PGE2 to be formed nonenzymatically.24 Interestingly, we did not detect mRNA for COX-2 in freshly removed SV or IMA, indicating that vessels from patients, even those with underlying coronary artery disease, do not have a basal expression of COX-2 at the time of surgery. In animal models, mild physical trauma causes COX-2 induction in vivo in rat carotid arteries.9 Thus, the induction of COX-2 we observed in the SV and IMA after 48 hours in organ culture is ...
1) Vision Training Grant - John Clark, Director. Multidisciplinary training in basic science and clinical aspects of vision research is conducted at both the pre- and post-doctoral levels. Faculty in 9 departments in the School of Medicine and the School of Arts and Sciences are preceptors for pre- and post-doctoral trainees in structural biology, cell and molecular biophysics, visual function and systems neurobiology using a variety of model systems in vertebrate animals and selected cell and organ culture systems. Vision training will emphasize modern technological approaches to clinical problems in the visual system in both normal and abnormal conditions. Interdisciplinary interactions that will develop new understanding of the scientific basis for important clinical problems in vision are encouraged.. 2) Development Biology Training Grant - David Raible Director. The program provides graduate work in developmental biology and supporting areas, including training in teaching, scientific ...
Chinese Journal of Cell Biology June, 2004 Vol.26 No.3 The comparision of organotypic culture spinal cord and internal spinal cord Li Chun Yan, Wang Xiaojuan Read more: en/upfiles/pdf/The_comparision_of_organotypic_culture_spinal_cord_and_internal_sp
Spontaneous neuronal activity prevails in virtual all brain regions in vivo as well as brain tissues in vitro. But its function, influence, or spatiotemporal patterns are ill-defined. In acute brain slice preparations, however, the level of spontaneous activity is reduced because of massively amputated neurites during slicing. Organotypic slice cultures self-restore neurites and synaptic connections and remodel the network complexity through the intrinsic rules of neural plasticity. Therefore, cultured slices could offer a unique opportunity for investigating some aspect of spontaneous activity. Here we focused on hippocampal networks and evaluated the similarity of spontaneous activity among acute slices, cultured slices and in vivo networks. Using functional multineuron calcium imaging and cell-attached patch-clamp recordings, we found that the mean firing rates of individual neurons of slice cultures did not differ from those of the in vivo hippocampus and were higher than those of acute ...
The productive program of the human papillomaviruses takes place in terminally differentiating squamous epithelia. In this chapter, we provide the protocols for robust production of HPV-18 in organotypic cultures of early passages of primary human keratinocytes. A critical step is the generation of genomic HPV plasmids in vivo by using Cre-loxP-mediated excisional recombination from a vector plasmid. We discuss the rationale for this approach. This system produces high yields of infectious virus and facilitates genetic analyses of HPV protein functions and their regulation in the context of recapitulated host tissue environment.. ...
The mechanisms by which human stem cells self‐organise into brain‐like tissues in 3D organoid culture are poorly understood. In this issue of The EMBO Journal, Renner and Lancaster et al demonstrate that in the absence of external stimuli, human cerebral organoids develop large forebrain structures that display specific landmarks of spatial and temporal patterning, including signalling centres producing known morphogens. The generation of cerebral organoids is therefore likely to reflect normal brain development.. See also: M Renner et al (May 2017) ...
The mechanisms by which human stem cells self‐organise into brain‐like tissues in 3D organoid culture are poorly understood. In this issue of The EMBO Journal, Renner and Lancaster et al demonstrate that in the absence of external stimuli, human cerebral organoids develop large forebrain structures that display specific landmarks of spatial and temporal patterning, including signalling centres producing known morphogens. The generation of cerebral organoids is therefore likely to reflect normal brain development.. See also: M Renner et al (May 2017) ...
Cha nges i n optical atte nuatio n, releva nt to cytochrome oxidase, of the rat bo ne periosteal tissue i n expla nted culture a nd huma n neuro nal cells i n three-dime nsio nal agarose co nstructs h
To address the current demand for 3D and organotypic culture reagents we have recently inaugurated our Organoid Resource Lab (ORL). Trevigens ORL has developed essential reagents such as our Cultrex® R-Spondin1 expressing cell line and our Organoid Harvesting Solution. We also offer a new line of organoid qualified matrices, BME type 2 and BME-R1, that are tested and qualified using enteroid progenitor cells.. ...
This study aimed to characterize fluoride-induced alterations in dentin mineralization within a dentin-pulp organ culture system. Tooth sections derived from male Wistar rat incisors were cultured in Trowel-type culture for 14 days, in the presence of 0 mM, 1 mM, 3 mM and 6 mM sodium fluoride. Tooth sections were processed and analyzed for uptake of fluoride, its subsequent effect on dentin mineralization by tetracycline hydrochloride incorporation and mineral composition, expressed as calcium/phosphorous (Ca/P) ratios. Tetracycline hydrochloride incorporation was demonstrated to decrease with increased fluoride exposure, accompanied by significant increases in both Ca/P ratios and fluoride incorporation. These findings provide further evidence that the established alterations in dentin formation during fluorosis are a consequence of disruption to the mineralization process, and provide a model system with which to investigate further the potential role the extracellular matrix plays in inducing ...
TY - JOUR. T1 - The effect of dexamethasone on glycosaminoglycans of human trabecular meshwork in perfusion organ culture. AU - Johnson, D. H.. AU - Bradley, J. M B. AU - Acott, Ted. PY - 1990. Y1 - 1990. N2 - The effect of dexamethasone treatment on glycosaminoglycans (GAG) in the human trabecular meshwork was studied by placing 20 pairs of eyes in perfusion organ culture. One eye received 550 nM dexamethasone in addition to culture medium; the fellow eye received culture medium only. 3H-glucosamine and 35S-sulfate were added to the medium for the final 48 hr of culture. The meshwork was then dissected, and the GAGs were isolated and subjected to sequential enzymatic degradation. Active labeling of hyaluronic acid, chondroitin sulfate, dermatan sulfate, keratan sulfate, and heparan sulfate was found in both control and steroid-treated eyes. Dexamethasone-treated eyes had an average 92% increase in the 3H-glucosamine incorporation rate in the undigestible GAG residue fraction after 14-21 days ...
We have used an in vitro system to study the effects of major histocompatibility complex class I binding peptides on thymic development. Fetal thymus lobes from mice deficient in the class I light chain (beta 2 microglobulin or beta 2 M-/-) were cultured for 10 d in vitro, during which time T cell precursors develop into mature T cells. In these organ cultures, as in the adult or neonatal beta 2 M-/- thymus, CD8+ mature T cells did not develop, demonstrating that the mature T cells seen during early murine thymic development are the result of the positive selection process. To these cultures we added various class I binding peptides with or without a source of exogenous beta 2M. CD8+ T cells developed to various degrees only in the presence of beta 2M and peptides. Using peptide mixtures of differing complexity, we showed that the efficiency of this process is dependent more on peptide complexity than on peptide concentration. These data argue for a specific role for peptides in the process of ...