Unlabelled: Tissue organoids are a promising technology that may accelerate development of the societal and NIH mandate for precision medicine. Here we describe a robust and simple method for generating cerebral organoids (cOrgs) from human pluripotent stem cells by using a chemically defined hydrogel material and chemically defined culture medium. By using no additional neural induction components, cOrgs appeared on the hydrogel surface within 10-14 days, and under static culture conditions, they attained sizes up to 3 mm in greatest dimension by day 28.
View Article and Find Full Text PDFThe potential of mesenchymal stromal cells (MSCs) to inhibit anti-tumor immunity is becoming increasingly well recognized, but the precise steps affected by these cells during the development of an anti-tumor immune response remain incompletely understood. Here, we examined how MSCs affect the steps required to mount an effective anti-tumor immune response following administration of adenovirus Fas ligand (Ad-FasL) in the Lewis lung carcinoma (LL3) model. Administration of bone marrow-derived MSCs with LL3 cells accelerated tumor growth significantly.
View Article and Find Full Text PDFThe characteristics of canine IL-17-producing cells are incompletely understood. Expression of mRNA encoding orthologs of IL-17 and the IL-17 receptor has been documented in tissues from dogs with arthritis, inflammatory bowel disease, and lymphoma; however, no associations have been found between IL-17 gene expression and disease phenotype in these conditions. Robust assessment of the role of IL-17-producing cells in dogs will require measuring the frequency of these cells in health and disease in balance with other lymphocyte subsets.
View Article and Find Full Text PDFThree-dimensional (3D) cell culture platforms are increasingly utilized due to their ability to more closely mimic the in vivo microenvironment compared to traditional two-dimensional methods. Limitations of currently available 3D materials include lack of cell attachment, long polymerization times, and inclusion of undefined xenobiotics, and cytotoxic cross-linkers. Evaluated here is a unique hydrogel comprised of polyelectrolytic complex (PEC) fibers formed by hyaluronic acid and chitosan (CT).
View Article and Find Full Text PDFBackground: Potent immunomodulatory effects have been reported for mesenchymal stem/stromal cells (MSCs), multipotent adult progenitor cells (MAPCs), and fibroblasts. However, side-by-side comparisons of these cells specifically regarding immunophenotype, gene expression, and suppression of proliferation of CD4(+) and CD8(+) lymphocyte populations have not been reported.
Methods: We developed MAPC and MSC lines from rhesus macaque bone marrow and fibroblast cell lines from rhesus dermis and assessed phenotypes based upon differentiation potential, flow cytometric analysis of immunophenotype, and quantitative RT-PCR analysis of gene expression.
Aviat Space Environ Med
June 2005
Background: Motion sickness is a common aeromedical problem that may occur in pilots exposed to increased gravitoinertial load in the head-to-foot direction (+Gz). Since motion sickness may affect autonomic nervous functions including cardiovascular control, it was hypothesized that it might interfere with cardiovascular responses to high +Gz, thereby decreasing G tolerance.
Methods: G tolerance and cardiovascular responses to increased G load were studied in nine subjects in a centrifuge environment under two conditions.
Aviat Space Environ Med
August 2003
Introduction: Pilots flying high-performance aircraft increase their acceleration tolerance by using straining maneuvers and anti-G suits. Recently, assisted positive pressure breathing has been added in some aircraft systems. This study assessed the effect of anti-G straining maneuvers on the G-protective properties of one such system, the AGE-39 anti-G ensemble used in the Swedish JAS 39 Gripen aircraft.
View Article and Find Full Text PDFAviat Space Environ Med
July 2002
Hypothesis: A newly developed hydrostatic anti-G suit is now commercially available. The suit is said to offer a high level of protection against +Gz acceleration. However, past experience shows that it is difficult to produce a hydrostatic suit with effective high-G protection.
View Article and Find Full Text PDFEur J Appl Physiol Occup Physiol
June 1998
Reductions in leg fluid volume of about 1/per leg or 10% of total leg volume have been reported during space flight. We wanted to test the hypothesis that a significant portion of these changes occur during the prelaunch and launch periods. Fluid volume changes in the lower leg were estimated in six men during a simulated Space Shuttle launch.
View Article and Find Full Text PDFA series of about 60 purine acyclonucleosides, most with guanine as the aglycone and a 4-carbon chain as the acyclic moiety, was examined for ability to inhibit purine nucleoside phosphorylase from human erythrocytes and calf spleen. Compounds with shorter and longer acyclic chains were less effective inhibitors. Synthetic procedures are described.
View Article and Find Full Text PDFA dynamometer designed for torque measurements of uni- and bilateral concentric and eccentric muscle actions of the quadriceps and hamstring muscle groups is described. Torque reproducibility and control of lever-arm position were studied using known standards. In vivo measurements assessed angular velocity, lever-arm acceleration, variability of torque between limbs and reproducibility of torque.
View Article and Find Full Text PDFIn an effort to improve the gastrointestinal absorption of (R,S)-9-[4-hydroxy-2-(hydroxymethyl)butyl]guanine [(+/-)2HM-HBG], various salts and esters of the compound were synthesized and pharmacokinetic experiments were performed in rats and monkeys. The sodium or hydrochloride salts and short-chain esters of (+/-)2HM-HBG showed bioavailability characteristics that were equally as poor as those of (+/-)2HM-HBG. However, the esters given as salts tended to be better absorbed than the parent compound.
View Article and Find Full Text PDFThe acyclic guanosine analog (R,S)-9-[4-hydroxy-2-(hydroxymethyl)butyl]guanine, (+/-)2HM-HBG, is an effective inhibitor of herpes simplex virus and varicella-zoster virus infections in vitro. This report is concerned with the pharmacokinetic evaluation of the drug in rats and monkeys and its antiviral activity in African green monkeys infected with simian varicella virus (SVV), a virus closely related to varicella-zoster virus that is also susceptible to inhibition by (+/-)2HM-HBG. Elimination half-lives in plasma following intravenous administration to monkeys (100 mumol/kg of body weight) ranged from 1.
View Article and Find Full Text PDFSudden decreases in cutaneous temperature induce an immediate ventilatory response, which has been termed the inspiratory or 'gasp' reflex. This respiratory response has been implicated as a contributing factor to cold water immersion drowning. In the present study, five subjects wearing either shorts or a variety of thermal protective apparel were immersed on separate occasions in 10 degrees C water.
View Article and Find Full Text PDFAntimicrob Agents Chemother
January 1987
The activity and mode of action of the new nucleoside analog (RS)-9-[4-hydroxy-2-(hydroxymethyl)butyl]guanine (2HM-HBG) against varicella-zoster virus (VZV) were determined. In cell culture, replication of different strains of VZV was inhibited to 50% by 0.4 to 0.
View Article and Find Full Text PDFJ Appl Physiol Respir Environ Exerc Physiol
January 1984
A flexible system has been developed for on-line breath-by-breath measurements of variables commonly included in studies of breathing pattern and mouth occlusion pressure (P0.1). The system, utilizing analog signals for mouth pressure and inspiratory flow as inputs, includes a breathing pattern monitor and a pneumatically driven occlusion device designed to be compatible with a low-cost microcomputer and analog and/or digital readout instruments.
View Article and Find Full Text PDFAntimicrob Agents Chemother
May 1983
A new compound, 9-(3,4-dihydroxybutyl)guanine, has been synthesized and its antiherpes activity determined. 9-(3,4-Dihydroxybutyl)guanine was selectively phosphorylated by herpes simplex virus thymidine kinase and had a high affinity for this enzyme, with an inhibition constant of 1.5 microM.
View Article and Find Full Text PDFThe therapeutic effects of topically applied foscarnet sodium and acyclovir on cutaneous infections due to herpes simplex virus type 1 (HSV-1) were studied in guinea pigs. Foscarnet cream (3%) reduced both the cumulative vesicle score and the time for healing when HSV-1 strains C42 and 79 were tested. The application of foscarnet in cream form resulted in a dose-dependent reduction in skin virus titers and vesicle scores at concentrations ranging from 0.
View Article and Find Full Text PDFJ Appl Physiol Respir Environ Exerc Physiol
June 1980
We studied the respiratory and circulatory effects in six healthy supine volunteers of continuous negative-pressure breathing (CNPB) at -15 and -30 cmH2O at rest and during dynamic leg exercies at 50% of individual working capacity. CNPB had no significant effects on respiratory minute volume, tidal volume, or arterial carbon dioxide tension. Mean arterial pressure remained essentially unchanged both at rest and during exercise, signifying that the reductions in intrathoracic pressure caused corresponding increases in left ventricular afterload.
View Article and Find Full Text PDFActa Physiol Scand
February 1979
To investigate the effects of sustained positive-pressure breathing (PPB) on the adaptation of respiratory and circulatory functions to exercise, 8 healthy volunteers were exposed to PPB of air at 15 and 30 cm H2O in the supine position at rest and while performing leg exercise at 50% of individual maximal working capacity. PPB was both subjectively and objectively better tolerated when combined with exercise than it was at rest. PPB at 30 cm H2O resulted in marked hyperventilation with alkalosis in the resting condition, but did not significantly affect respiratory minute volume, blood gases or acid-base balance during exercise.
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