The unidirectional prosaccade switch-cost: correct and error antisaccades differentially influence the planning times for subsequent prosaccades.

Antisaccades produce longer reaction times (RT) than their prosaccade counterparts and this latency increase has been linked to an oculomotor 'pre-setting' that prevents the evocation of a stimulus-driven prosaccade. Moreover, a consequence of oculomotor pre-setting is a lengthening of the RTs associated with a subsequent prosaccade. The goal of the present study was to determine whether the constituent elements associated with planning a correct antisaccade (i.

Modifying influence of enalaprilat on mesangial cell DNA synthesis induced by hydrogen peroxide.

This study examined the effect of the angiotensin converting enzyme (ACE) inhibitor, enalaprilat, on mesangial cell (MC) DNA synthesis induced by H2O2, IL-6 and PDGF. MC were incubated with enalaprilat (2.5-100 mumol/l) alone and together with combinations of H2O2 (3 daily pulses of 10(-6) mol/l), IL-6 (5 ng/ml) and PDGF (10 ng/ml).

Mesangial cell DNA synthesis induced by hydrogen peroxide, interleukin-6, and platelet-derived growth factor: effects of indomethacin and dazmegrel.

This study indirectly examined the role of prostanoids (PG) in mediating rat mesangial cell (MC) DNA synthesis induced by hydrogen peroxide (H2O2), interleukin 6 (IL-6), and platelet-derived growth factor (PDGF). MC were exposed to three daily pulses of 10(-6) mol/l H2O2 alone or in combination with IL-6 (5 ng/ml) or PDGF (10 ng/ml). In order to examine (indirectly) the role of PG in mediating changes in MC DNA synthesis, indomethacin (1.

Ex vivo phase 1 evaluation of the DeBakey/NASA axial flow ventricular assist device.

A small ventricular assist device intended for long-term implantation has been developed by a cooperative effort between the Baylor College of Medicine and the NASA/Johnson Space Center. To date, in vitro tests have been performed to address hemolysis and pump performance issues. In this Phase 1 study, we assessed the durability and atraumatic features aiming for 2 day implantation.

Development of an axial flow ventricular assist device: in vitro and in vivo evaluation.

A collaborative effort between Baylor College of Medicine and NASA/Johnson Space Center is underway to develop an axial flow ventricular assist device (VAD). We evaluated inducer/impeller component designs in a series of in vitro hemolysis tests. As a result of computational fluid dynamic analysis, a flow inducer was added to the front of the pump impeller.

A fluid dynamic analysis using flow visualization of the Baylor/NASA implantable axial flow blood pump for design improvement.

The Baylor/NASA Axial Blood Flow Pump has been developed for use as an implantable left ventricular assist device (LVAD). The pump is intended as an assist device for either pulmonary or systemic circulatory support for more than 3-months' duration. To date the pump provides acceptable results in terms of thrombus formation and hemolysis (IH of 0.

Does hematocrit affect in vitro hemolysis test results? Preliminary study with Baylor/NASA prototype axial flow pump.

The effect of hematocrit (Ht) on in vitro hemolysis test results (i.e., index of hemolysis) was evaluated using a Baylor/NASA prototype axial flow pump.

Axial flow ventricular assist device: system performance considerations.

A cooperative effort between Baylor College of Medicine and NASA/Johnson Space Center is under way to develop an implantable left ventricular assist device for either pulmonary or systemic circulatory support for more than 3 months' duration. Using methodical evaluation and testing, an implantable axial pump has been systematically improved. These improvements include the addition of an inducer as a pumping element in front of the impeller and the construction of an efficient brushless direct current motor.

Development of the Baylor/NASA axial flow ventricular assist device: in vitro performance and systematic hemolysis test results.

Our newly developed axial flow pump consists of a flow tube, an internal rotating impeller, and a fixed flow stator (we call the stator) behind the impeller. This pump produces a flow of 3 to 8 L/min against 50 to 150 mm Hg pressure difference, respectively, in the range of 10,000 to 16,000 rpm. An axial flow pump that will be used as a ventricular assist device (VAD) has to have low hemolytic and good antithrombogenic characteristics.

Interactions of hydrogen peroxide with interleukin-6 and platelet-derived growth factor in determining mesangial cell growth: effect of repeated oxidant stress.

1. This study examined the influence of H2O2, interleukin-6 and platelet-derived growth factor on the proliferation of rat mesangial cells. Mesangial cells were exposed to either a single pulse or three daily pulses of H2O2 (10(-8)-10(-4) mol/l), alone or in combination with interleukin-6 (5 ng/ml) and/or platelet-derived growth factor (10 ng/ml).

In vitro performance of the Baylor/NASA axial flow pump.

A cooperative effort between Baylor College of Medicine and NASA/Johnson Space Center is under way to develop an implantable axial flow left ventricular assist device (LVAD). The pump is intended as an assist device for either pulmonary or systemic circulatory support for more than 3 months' duration. Currently, in vitro studies are under way to reduce the hemolysis generated by the axial flow pump.

Localisation of alpha, mu and pi class glutathione S-transferases in kidney: comparison with CuZn superoxide dismutase.

We describe studies in whole kidney, cortical and medullary homogenates and, glomerular cells in culture to determine the relative levels of expression of alpha (Ya, Yc, Yk), mu (Yb1/Yb2), pi (Yf) glutathione S-transferases (GST) and CuZn superoxide dismutase (CuZn SOD) in different regions of the nephron. Immunoblotting and immunohistochemistry were used to demonstrate relatively weak expression of alpha, mu GST and, CuZn SOD in the glomerulus compared to that in particularly distal tubules. Whilst expression of Ya was found within glomerular cells, Yc, Yk and Yf were not detected.

Dose-dependent effects of angiotensin converting enzyme (ACE) inhibitors on glomerular prostanoid production by normotensive rats.

1. This study was designed to investigate whether the angiotensin converting enzyme (ACE) inhibitors, captopril, enalapril and fosinopril have a dose-dependent effect on the production of prostaglandin E2 (PGE2), prostaglandin I2 (prostacyclin, PGI2) and thromboxane A2 (TxA2) by glomeruli isolated from normotensive Wistar-Kyoto rats. 2.

Oxidant stress and glomerular prostanoid production: influence of angiotensin converting enzyme inhibition.

1. The effect of H2O2 (4.7 x 10(-9) -4.

Oestradiol-induced hypotension in spontaneously hypertensive rats: putative role for intracellular cations, sodium-potassium flux and prostanoids.

1. The effect of oestradiol alone and in combination with indomethacin on blood pressure, erythrocyte cation concentration and Na(+)-K+ flux has been studied in adult female normotensive and spontaneously hypertensive rats. 2.

Glomerular injury induced by hydrogen peroxide: modifying influence of ACE inhibitors.

The sensitivity of isolated glomeruli from normotensive (Wistar-Kyoto, WKY) and spontaneously hypertensive (SHR) strains to oxidant stress was studied by determining the incidence of pyknosis, karyohexis and karyolysis after incubation with different concentrations of hydrogen peroxide (H2O2) (4.7 x 10(-9) - 10(-3) M). Even though the proportion of glomeruli containing nuclei that demonstrated these features increased progressively with increasing concentrations of H2O2, the number of severely damaged glomeruli was relatively small even at concentrations of 4.

Effect of angiotensin-converting enzyme inhibitors on glomerular eicosanoid production in normotensive and spontaneously hypertensive rats.

1. This study was designed to examine the production of certain eicosanoids (prostaglandin E2), prostacyclin (as 6-keto-prostaglandin F1 alpha) and thromboxane A2 (as thromboxane B2) by glomeruli isolated from normotensive Wistar-Kyoto and spontaneously hypertensive rats both before and after the administration of one of three angiotensin-converting enzyme inhibitors, captopril, enalapril or fosinopril, for 10 days. 2.

Idiopathic retroperitoneal fibrosis--an update.

Our belief in a non-operative approach to the management of RPF hinges on the differential diagnosis; the closer the approach to the certainty in establishing the diagnosis, the less is the risk of error in medical treatment. Careful history taking and intelligent use of the available range of investigations should allow near certainty in diagnostic accuracy and thus the progression to non-operative management in most patients. The cause of RPF remains obscure, further research into the possibility of an auto-immune reaction, perhaps a response to some factor introduced in the latter half of this century would seem to offer most prospect of success.

The effect of angiotensin converting enzyme inhibitors on isolated glomeruli.

The following study was designed to examine the effect of the angiotensin converting enzyme (ACE) inhibitors captopril and enalapril on certain biological and physiological activities of isolated preparations of glomeruli from normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive SHR rats. The results suggest that the contractile response of glomeruli from SHR to exogenous angiotensin II (Ang II) is significantly enhanced by captopril whereas it has a different effect on those from normotensive (WKY) rats. These effects are unrelated to changes in glomerular Ang II binding or the level of plasma renin activity (PRA), but they do depend partially on the sodium status of the animal.

Influence of age on glomerular binding of angiotensin II in normotensive and spontaneously hypertensive rats.

1. Glomerular angiotensin II (ANG II) binding has been studied in normotensive (NTR) and spontaneously hypertensive (SHR) rats at 5, 10, 15 and 20 weeks of age. 2.

Differences in glomerular binding and response to angiotensin II between normotensive and spontaneously hypertensive rats.

1. Angiotensin II (ANG II) binding and the physiological response to exogenous ANG II have been studied in isolated glomerular preparations from normotensive (NTR) and spontaneously hypertensive (SHR) rats. 2.

Non-operative management of retroperitoneal fibrosis.

It is generally recognized that in many patients the ureteric obstruction and other manifestations of non-malignant retroperitoneal fibrosis will respond to treatment with corticosteroids. However, most surgeons are reluctant to use steroids as the primary treatment for patients with this condition, mainly because of the risk of mismanagement of malignant retroperitoneal fibrosis. Our experience in the care of 17 patients with non-malignant retroperitoneal fibrosis has led us to believe that an initial non-surgical approach is both safe and preferable.

Oestrogen-induced changes in renal haemodynamics in the rat: influence of plasma and intrarenal renin.

The effect of oestrone acetate (in total doses of 5 and 10 mg) on systemic and renal haemodynamics and the renin-angiotensin system has been studied in adult female rats. The administration of 10 mg of oestrogen resulted in a significant fall in renal blood flow associated with significant rises in both renal vascular resistance and mean arterial pressure. No changes were noted in cardiac output or total peripheral resistance at either dose.