The stomach, cholecystokinin, and satiety

The stomach of the rhesus monkey empties liquids in a fashion that varies with the character of the solutions. Physiological saline empties exponentially. Glucose solutions empty biphasically--rapidly for the first minutes, then slowly and proportionately to glucose concentration to deliver glucose calories through the pylorus at a regulated rate (0.4 kcal/min). This prolonged and regulated second phase of gastric emptying depends on intestinal inhibition of the stomach. Cholecystokinin (CCK), a hormone released by food in the intestine, is an inhibitor of gastric emptying. In vitro receptor autoradiography demonstrates CCK receptors to be clustered on the circular muscle of the pylorus. Exogenous CCK, in doses that inhibit gastric emptying, will reduce food intake only if combined with an infusion of saline in the stomach. These observations indicate how gastric distension can be a means for provoking satiety. The variably sustained distension produced by the stomach's slow, calorically regulated emptying could prolong intermeal intervals and thus permit high-calorie meals to inhibit further caloric intake over time. CCK, by directly inhibiting gastric emptying during a meal, could promote gastric distension and so restrict the duration and size of individual meals.     

The K-factor,Covitality, and personality

We present a psychometric test of life history theory as applied to human individual differences using MIDUS survey data (Brim et al. 2000). Twenty scales measuring cognitive and behavioral dimensions theoretically related to life history strategy were constructed using items from the MIDUS survey. These scales were used to construct a single common factor, the K-factor, which accounted for 70% of the reliable variance. The scales used included measures of personal, familial, and social function. A second common factor, Covitality, was constructed from scales for physical and mental health. Finally, a single general factor, Personality, was constructed from scales for the “Big Five” factors of personality. The K-factor, covitality factor, and general personality factor correlated significantly with each other, supporting the prediction that high K predicts high somatic effort and also manifests in behavioral display. Thus, a single higher-order common factor, the Super-K factor, was constructed that consisted of the K-factor, covitality factor, and personality factor.     

The Na,K-ATPase

The energy dependent exchange of cytoplasmic Na⁺ for extracellular K⁺ in mammalian cells is due to a membrane bound enzyme system, the Na,K-ATPase. The exchange sustains a gradient for Na⁺ into and for K⁺ out of the cell, and this is used as an energy source for creation of the membrane potential, for its de- and repolarisation, for regulation of cytoplasmic ionic composition and for transepithelial transport. The Na,K-ATPase consists of two membrane spanning polypeptides, an -subunit of 112-kD and a -subunit, which is a glycoprotein of 35-kD. The catalytic properties are associated with the -subunit, which has the binding domain for ATP and the cations. In the review, attention will be given to the biochemical characterization of the reaction mechanism underlying the coupling between hydrolysis of the substate ATP and transport of Na⁺ and K⁺.     

The Characeae, 1951

The Botanical Review -     

The deafness,onycho-osteo-dystrophy,mental retardation syndrome

Summary Two new cases of the D.O.O.R. syndrome are reported. The patients described showed most of the characteristics described by Cantwell (1975) and some others that may represent additional clinical findings of this rare syndrome.