Mast-cell reaction in precancerous mouse skin: an immunological response?

The promotion phase of carcinogenesis in mouse skin is accompanied by a mast-cell reaction in the upper dermis. Evidence is presented which suggests that this may be an immunological response, whereby distant lymphocytes migrate to the area and, in the presence of young fibroblasts, become transformed into tissue mast cells.     

Urinary metabolites of amixetrine in man and in the dog

The urinary metabolites of N-(2-phenyl-2-isoamyloxy) ethyl-pyrrolidine-hydrochloride (amixetrine) studied in man and in the dog demonstrated a comparable mode of transformation of the drugs for both species. The principal metabolites of amixetrine isolated from urine and purified with the aid of chromatographic techniques were identified by IR, NMR and mass spectrometry. Untransformed amixetrine and (1,2-phenyl-1-hydroxy)ethylpyrrolidine were found in small quantities. In man, as in the dog, the principal metabolite coming from an omega-1-oxidation of the isoamyl chain corresponded to 2-phenyl-2-butoxy-(3-methyl-3-ol)ethyl-pyrrolidine.     

Haemodynamics and body fluid volumes in response to fluid loading in conscious dogs: non-excretory renal influences

1. Twelve conscious, chronically instrumented dogs were subjected to rapid loading with sodium chloride solution (150 mmol/1; saline) before and 1 day after bilateral nephrectomy (six dogs) or ureterocaval anastomosis (six dogs). Measurements were performed up to 3 h after the fluid load and included cardiac output with an electromagnetic flowmeter, mean arterial pressure and right atrial pressure with chronically implanted catheters, interstitial fluid pressure with a plastic capsule, heart rate, extracellular fluid volume, erythrocyte volume, plasma volume, plasma protein concentration and other variables. 2. The increase in cardiac output in response to saline load was significantly prolonged in the anephric dogs compared with those with uretero-caval anastomosis; mean arterial pressure, right atrial pressure and heart-rate changes were similar in both groups. 3. Plasma volume appeared to increase more in the anephric dogs than in those with uretero-caval anastomosis during the first hour after the infusion, although conflicting results were obtained with different estimates of plasma volume changes. Interstitial fluid pressure increased significantly less in the anephric dogs in the early stages of the fluid load. 4. Effective vascular compliance (the ratio of the change in blood volume to the change in right atrial pressure) appeared increased in the anephric dogs. On the other hand, the change in cardiac output for a given change in right atrial pressure was found to increase after bilateral nephrectomy. 5. It is suggested that the prolonged increase in cardiac output observed in anephric dogs was not the consequence of preferential plasma volume expansion nor of decreased venous compliance, but may reflect an alteration in the cardiac function curve.     

Effect of intrajejunal fat on meal-stimulated acid and gastrin secretion in man

The effect of intrajejunal fat infusion on meal-stimulated gastric acid and gastrin secretion was studied in 8 healthy volunteers. Intrajejunal fat significantly reduced the acid response to a meal, measured by intragastric titration, as compared to intrajejunal infusion of saline. While serum gastrin concentrations rose from fasting levels to a constant plateau after the meal when saline was infused, fat infusion resulted in a transitory decrease in serum gastrin concentration followed by a significant increase. It is concluded that inhibition of gastrin release only plays a minor role, if any, in the observed fat-induced jejuanl inhibition of meal-stimulated acid secretion.     

Effect of temperature on binding of warfarin by human serum albumin

The in vitro binding of warfarin by human serum albumin was studied at various temperatures and at pH 7.4 by a frontal gel filtration technique. The results can be best described in terms of a two class-of-binding site model, in which the numbers of primary and secondary sites are constrained to the average values for all experiments (n1 = 1.38 and n2 = 3.73). Analysis of the temperature dependence of the binding yielded the following thermodynamic parameters: deltaH1 =-2.55 kcal/mole, deltaS1=16.1 eu, and deltaF1=-7.34 kcal/mole for the primary binding and deltaH2=-5.08 kcal/mole, deltaS2=-1.10 eu, and deltaF2=4.72 kcal/mole for the secondary binding. Calculations based on these results showed that, for the therapeutic concentration range, warfarin was over 99% bound to albumin present in physiological concentration. These findings are compared and contrasted to binding data in the literature for warfarin and salicylate.     

Estimates of motor vehicle seat belt effectiveness and use: implications for occupant crash protection

Estimates of the effectiveness of seat belts, when used, in reducing motor vehicle occupant deaths vary widely. A recently publicized claim by one analyst that seat belts reduce vehicle occupant deaths 70-80 per cent is based on studies found to contain fundamental systematic error. Deaths occur only 50 per cent less often to belted compared to nonbelted vehicle occupants in crashes, according to previously unanalyzed data from three U.S. states during recent years. New belt systems would be about 60 per cent effective with 100 per cent use. But surveys of observed belt use in 1975 U.S. cars indicate that two-thirds of drivers were not using belts. Prospects for widespread adoption and enforcement of belt use laws in the U.S. are not encouraging. Substantial reductions in fatal and other injuries would result from the adoption of requirements mandating automatic (passive) protection for front seat occupants in crashes with forward decelerations.     

Observations on Research Training.

This comment suggests a plan for implementing the goals of graduate training programs. The principal feature of the plan is the actual participation of the student in research every semester. The required amount of time could vary from approximately three semester hours in the student's first year to approximately nine semester hours in his last year. Benefits of the plan are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Estimation of hue discrimination thresholds using a computer interactive method

An experimental approach is described for measuring colour discrimination thresholds of human observers. Special software was developed for the accurate display of colour pairs on a high resolution CRT, using serial feedback from a spectroradiometer. Discrimination thresholds between a test and a target colour are determined by repeatedly showing an observer a circle composed of four separate quadrants, one of which has a different colour from the other three. Three quadrants are of the test colour and one of the target colour, or vice versa. Observers are asked to select the quadrant that differs from the others. An experiment is described where hue‐dependent effects affecting hue discrimination are investigated. Eighteen hue threshold values around the hue circle, at constant L = 51 and C = 25, were measured for three observers. Hue thresholds were found to vary around the hue circle, exhibiting an abrupt change in the blue to purple region (240° ≤ h_ab,10 = 300°) This change is not fully accounted for by any CIELAB‐based colour difference formula, including the most recent CIEDE2000 formula. © 2005 Wiley Periodicals, Inc. Col Res Appl, 30, 410–415, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20153