A study of grating contrast judgement

Subjects judged the contrast of sinewave and narrow-bandwidth random gratings. The apparent contrast of gratings formed by summing two component gratings widely separated in frequency is independent of the relative phase of the component gratings and is equal to a linear sum of the subjective contrasts of the components when presented separately. A model is proposed in which the perceived contrast is formed by a linear sum of the outputs of multiple nonlinear channels.     

Posthaemorrhagic iron deficiency. Clinical course, 59Fe whole-body iron losses, and oral iron supplementation.

Clinical and laboratory data characterizing post-haemorrhagic anaemia with still normal iron stores and posthaemorrhagic iron deficiency in the manifest, latent or prelatent stage are presented. Initially, increased 59Fe whole-body iron losses (greater than 0.1-3.6%/day) returned to normal range (less than 0.1%/day) after haemostasis. Subsequently, slow increase of haemoglobin and repletion of iron stores occurred under normal diets. Manifest, latent, and prelatent iron deficiencies were corrected much more rapidly by total doses of 12.0, 10.5 and 8.0 g iron (Fe2+ sulfate), respectively, when 2 X 50 mg/day were given in quick-release capsules apart from meals.     

Sprouting in intact sartorius muscles of the frog following contralateral axotomy

The intact hind limb sartorius muscle of the frog was examined anatomically for sprouting following axotomy of the sciatic nerve that contains motor axons innervating the contralateral sartorius muscle. The incidence of sprouting in intact muscles of experimental animals increased more than 3-fold over normal. Thus, contralateral axotomy produces sprouting in intact sartorius muscles much the same as it does in cutaneous-pectoris and piriformis muscles of the frog.     

Platelet activation detected by turbidometric shape-change analysis: differential influence of cytochalasin B and prostaglandin E1.

Activation of platelets by specific stimuli is associated with changes in the light transmission of the platelet suspension. EDTA avoids aggregation of activated platelets but does not interfere with platelet activation. Three optical effects which require increasing stimulus concentrations are characterized: 1) Disc-sphere transformation of platelets (=shape change I) is reflected by a decrease in the light transmission (LT) and disappearance of the change in LT when the stirring mechanism is switched on or off. 2) Higher inducer concentrations are necessary to elicit a further decrease in LT (=shape change II) which is detected independently on stirring. 3) A final increase in LT follows the shape change with stronger stimuli and indicates secretion. 2) and 3) are also found during stimulation of spheroid platelets obtained under certain washing conditions or by pre-treatment with cold. Cytochalasin B (CB) 60 μM impairs the disc-sphere transformation. Low concentrations of CB (2 μM) strongly enhance the final increase in LT and the extrusion of serotonin from platelets stimulated by activators of the release but not by ADP, epinephrine, or diamide. Prostaglandin E₁ (PGE₁) inhibits the three optical effects and the release. The requirement for the stepwise increase in PGE₁ concentrations to inhibit disc-sphere transformation, shape change II, and the extrusion phase of the release reaction confirms the conclusion that the optical parameters indicate varying degrees of platelet activation.     

Effect of processing on digestibility and the blood glucose response: a study of lentils

To test the effect of processing on digestibility and the glycemic response to a leguminous seed, a group of eight healthy volunteers took a series of breakfast test meals containing either lentils which had been processed in four different ways or the same amount of carbohydrate as white bread. Lentils, boiled for 20 min, resulted in a flattened blood glucose response by comparison with bread. This was unaltered by blending the lentils to a paste or boiling them for an additional 40 minutes. However the blood glucose response was significantly enhanced by drying the boiled blended lentils for 12 h at 250 degrees F. In vitro digestion with human saliva showed the rate of sugars released from the food related positively to the blood glucose rise. Breath hydrogen studies indicated that carbohydrate malabsorption was too small to account for differences in the blood glucose response. These results emphasize the importance of processing in determining digestibility and hence the glycemic response to a food.