59 research outputs found
Extension of finite volume compressible flow solvers to multidimensional, variable density zero Mach number flows
When attempting to compute unsteady, variable density flows at very small or zero Mach number using a standard finite volume compressible flow solver one faces at least the following difficulties: (i) Spatial pressure variations vanish as the Mach number
Amelioration of immune complex-mediated glomerulonephritis by synthetic protease inhibitors.
Proteases are involved in the pathogenesis of inflammatory diseases by participating in the activation of
mediator systems and by producing proteolytic tissue injury. Homeostatic control of inflammation
is accomplished in part by physiologic protease
inhibitors. The authors investigated the effectiveness of a number of synthetic protease inhibitors
in ameliorating the glomerular injury induced by
immune complex-mediated glomerulonephritis
in mice. Two amidine-type protease inhibitors, bis
(5-amidino-2-benzimidazolyl)methane and 1,2-bis
(5-amidino-2-benzimidazolyl)ethane, had the greatest effects. They caused a marked reduction in glomerular
necrosis (P < 0.001) but did not affect the amount or
site of immune complex localization or leukocyte influx. The inhibition constants of the protease inhibitors
against nine purified physiologic proteases were determined. These results were discussed in relation to the
effectiveness of the protease inhibitors in reducing glomerular injury. This investigation indicates that the
administration of synthetic protease inhibitors can
have a beneficial effect on immune-mediated inflammatory injury
Suppression of respiratory syncytial virus infection in cotton rats by bis(5-amidino-2-benzimidazolyl)methane.
Intraperitoneal administration of bis(5-amidino-2-benzimidazolyl)methane at well-tolerated daily doses of 25 mg/kg subsequent to challenge and for 3 days thereafter effected over a 1-log reduction in the amount of virus recovered from lungs of cotton rats inoculated intratracheally with respiratory syncytial virus. When animals were immunosuppressed to prolong virus shedding, the reduction in recovered virus achieved with a 7-day dosing schedule of bis(5-amidino-2-benzimidazolyl)methane exceeded 2 logs
In vitro inhibition of human sarcoma cells' invasive ability by bis(5-amidino-2-benzimidazolyl)methane--a novel esteroprotease inhibitor.
Bis(5-amidino-2-benzimidazolyl)methane (BABIM) is a synthetic aromatic amidine compound which has a number of important biochemical effects, including inhibition of a family of esteroproteases (trypsin, urokinase, plasmin) previously linked to the complex process of tumor invasion. Previous work has suggested that exogenous natural protease inhibitors can block invasion of tumor cells across basement membranes (BM) in vitro. The authors studied the effect of BABIM on the human cell line HT-1080 with the use of a quantitative in vitro amnion invasion assay system. They have verified the ability of these cells to grow in nude mice and metastasize via the lymphatics or blood vessels on the basis of the route of administration of the inoculum. Cells which were able to actively cross the entire BM were trapped on filters and counted by both brightfield microscopy and by beta scintillation counting of cells whose DNA was labeled with tritiated thymidine. In agreement with either counting technique, BABIM, at a concentration of 10(-4) M, significantly inhibited invasion (P less than 0.005) over the 7-day course of the experiments. Under these conditions, the inhibitor was nontoxic and did not alter the attachment of the cells to the amniotic membrane. Furthermore, a highly significant inhibition of invasion (P less than 0.001) was also demonstrated across a variation in molar concentration of BABIM of more than 2 orders of magnitude. Most remarkably, cells were initially inhibited in their ability to invade in the presence of between 10(-9) and 10(-3) M BABIM. Measurement of Type IV specific collagenase in media from these cells shows a significant inhibition of activity in the presence of BABIM. These results suggest two, not necessarily exclusive, alternative interpretations: first, that inhibition of the proteolytic steps along the pathway of activation of basement membrane degrading enzymes results in inhibition of invasion; second, that arginine directed esteroproteases may work in concert with cellular collagenolytic metalloproteinases in the process of invasion by human tumor cells through native matrix barriers
The Role of Bile in the Regulation of Exocrine Pancreatic Secretion
As early as 1926 Mellanby (1) was able to show that introduction of bile into the duodenum of anesthetized cats produces a copious flow of pancreatic juice. In conscious dogs, Ivy & Lueth (2) reported, bile is only a weak stimulant of pancreatic secretion. Diversion of bile from the duodenum, however, did not influence pancreatic volume secretion stimulated by a meal (3,4). Moreover, Thomas & Crider (5) observed that bile not only failed to stimulate the secretion of pancreatic juice but also abolished the pancreatic response to intraduodenally administered peptone or soap
High accuracy synchrotron radiation interferometry with relativistic electrons
A high-precision hypernuclear experiment has been performed at the Mainz
Microtron (MAMI) to determine the hypertriton {\Lambda} binding energy via
decay-pion spectroscopy. A key element of this measurement is an accurate
calibration of the magnetic spectrometers with the MAMI beam. For such an
absolute calibration with small statistical and systematic uncertainties the
undulator light interference method will be applied. In this contribution the
basic principle of this method is discussed and the analysis status of the
measured synchrotron radiation spectra is presentedComment: The 13th Biennial Conference on Classical and Quantum Relativistic
Dynamics of Particles and Fields (IARD22
Structure-Activity Relationships for the Inhibition of Plasmin and Plasminogen Activation by Aromatic Diamidines and a Study of the Effect of Plasma Proteins on the Inhibition Process
Plasma Thromboplastin Component (Christmas Factor, Factor IX) Levels in Stored Human Blood and Plasma
Die Hemmung der Trypsinogen- und Chymotrypsinogenaktivierung durch p-Aminomethylbenzoes�ure (PAMBA) und andere Aminocarbons�uren
Enhancement of respiratory syncytial virus-induced cytopathology by trypsin, thrombin, and plasmin.
A series of proteases of diverse substrate specificity were tested for their effect on respiratory syncytial virus-induced cytopathology. Three of the enzymes, thrombin, plasmin, and trypsin, were able to augment significantly the fusion of virus-infected A549 cells. On a concentration basis, thrombin was the most active promoter, followed by plasmin and then trypsin. Hirudin, a specific thrombin inhibitor, blocked the fusion-enhancing property of thrombin, yet had no influence on the basal rate of fusion in the absence of the enzyme. By contrast, the amidine-type inhibitors of trypsin-like proteases, bis(5-amidino-2-benzimidazolyl)-methane (BABIM), blocked not only the thrombin effect, but also the fusion in the thrombin-free controls. The suppressive activity of BABIM was observed at concentrations so low as to exclude any direct inhibitory effect on thrombin itself. These results make it seem very likely that thrombin advances cell fusion by activating a BABIM-sensitive protease. Plasmin and trypsin can be expected to act in a similar manner
- …