Nello Pace

Some physical and chemical properties of crystalline α-glycerophosphate dehydrogenase☆

Abstract α-Glycerophosphate dehydrogenase was crystallized as rectangular plates, having the following properties: s 20, w = 6.5 × 10 −13 sec. , V = 0.75 cc./g. and f f 0 = 1.4 . The molecular weight has been estimated to be 173,000 g./mole. α-Glycerophosphate dehydrogenase was found to be relatively thermolabile, and is most stable at pH 5.7. Approximate Michaelis constants at pH 7.0 were found as follows: for α-glycerophosphate, 1.1 × 10 −4 M ; for dihydroxyacetone phosphate, 4.6 × 10 4 M ; for DPN, 3.8 × 10 −4 M . The equilibrium constant for the oxidation of α-glycerophosphate was found to be 5.8 × 10 −12 M at 25 °C. All the properties studied indicate that within the pH range 7–8 the reaction favors formation of α-glycerophosphate.

Frequency distribution and discrimination probability of twelve protein genetic variants in human blood as functions of race, sex, and age.

Fresh blood samples were obtained from 6004 whites, 1025 blacks, 1596 Chicano/Amerindians, and 3053 Asians of California and Hawaii. The samples were typed for ABO and Rh groups and were analyzed electrophoretically for ten genetically determined protein variant systems. The effects of race, age, and sex on phenotypic frequencies within each of the twelve genetic systems were investigated. Large frequency differences were found between races but not between different age and sex subgroups within races. It was also demonstrated that the twelve genetic systems behaved statistically independently. Discrimination probabilities were computed for each of the four ethnic groups. These serve as a measure of the effectiveness of the twelve genetic systems examined in individualizing blood samples. The method is discussed for computing the probability that a randomly chosen individual of a given ethnic group possesses the same blood phenotypes as found in a predetermined sample of blood. The results presented here should prove useful in the investigation of civil and criminal cases involving blood samples.

Application of Atomic Absorption in the Study of Na, K, Mg, and Ca Binding by Cellular Membranes

Atomic-absorption spectrophotometry is applied in the analysis of biological membrane materials for micromolar levels of the physiologically important cations, Na, K, Mg, and Ca. Instrumental parameters and chemical interferences are investigated and a method for the measurement of all four cations in a single sample of ashed membrane material is formulated, tested, and applied. Results are highly satisfactory, and demonstrate that atomic-absorption spectrophotometry affords biologists a powerful and sensitive tool for the study of the important rôle played by inorganic ions in living systems.

Distribution of Gene Frequencies and Discrimination Probabilities for 22 Human Blood Genetic Systems in Four Racial Groups

Gene frequencies were computed in four racial categories from 5956 blood donors from California, Hawaii, Mexico City, and Texas. Calculations were based on the phenotypic distribution of 22 blood genetic systems including 7 blood groups and 15 genetically controlled polymorphic proteins and enzymes. Matching probabilities for 20 systems were approximately 1 in 100 000 Asians, 1 in 200 000 blacks, 1 in 330 000 Mexicans, and 1 in 1 000 000 whites. The complementary discrimination probability, which measures the likelihood that two random individuals do not match, was, for practical purposes, unity. The combined new technology for blood grouping and electrophoresis using cellulose acetate membranes provides a powerful individualizing and discriminating tool for forensic science investigation.

Studies of Human Peripheral Blood Flow: The Effect of Injection Volume on the Intramuscular Radiosodium Clearance Rate

The effects of changes in injection volume on the intramuscular radiosodium clearance rate was investigated in six normal young men. The clearance rate was found to be quite sensitive to the volume of solution injected, and an increase in the rate of clearance corresponding to a decrease in volume was uniformly noted. Rigid control of the injection volume is necessary when this method is used for regional blood flow measurements.

Chemical and ionization interferences in the atomic absorption spectrophotometric measurement of sodium, potassium, rubidium, and cesium

Abstract Although chemical and ionization interferences significantly affect the atomic absorption signal of the alkali metals, suitable corrective measures permit accurate analysis of these elements. The observed interferences are affccted in opposite ways by flame temperature, chemical depression of absorption produced by anions decreasing, and ionization enhancement produced by cations increasing with increasing flame temperature. Anionic depression is small in an acetylene-air flame and moderately large in a propane-air flame, increasing in the sequence sulfate M phosphate depressing cesium absorbance approximately 40%. Conversely, ionization enhancement by cations is small in a propane-air flame and large in an acetyleneair flame, the effect on rubidium absorbance increasing in the sequence Mg M cesium producing a twoflod increase in absorbance. This is in the order of decreasing ionization potentials, indicating a direct relationship between ionization potential, degree of ionization, and enhancement produced. From consideration of the over-all effect of flame temperature on various interferences, we conclude that the propane-air flame is probably the most satisfactory for alkali metal analysis, especially for rubidium and cesium. Recovery studies on dialyzed and ashed rat liver microsomes and known controls demonstrate that addition of 15 m M lanthanum, to minimize anionic interferences, and addition of moderate concentrations of cesium, rubidium, or potassium, to minimize cationic enhancement, permit accurate and reliable measurement of the alkali metal cations in biological materials in the presence of potentially interfering cations and anions.

The Measurement of Total "Sodium Space" and Total Body Sodium in Normal Individuals and in Patients with Cardiac Edema

Total sodium space and total body sodium contents were determined in four groups of individuals with the aid of radiosodium24. There appears to be an increase in these values with age, but the presence of well compensated cardiovascular disease in the older age group does not significantly alter the magnitude of these measurements. When congestive failure with edema occurs, there is a marked increase in total sodium space and total body sodium. The increase in total sodium space shows a good correlation with the clinical degree of edema.

Distribution of α-glycerophosphate dehydrogenase in normal rats☆

Abstract Over 95% of the soluble α-glycerophosphate dehydrogenase activity of rat liver cell homogenate was found in the supernatant fraction, indicating an exclusively extraparticulate localization of this enzyme. Organ distribution measurements show the bulk of the enzyme to be in the skeletal musculature (87–95%), with appreciable amounts in the liver (4–12%) and kidney (1%). Only barely detectable activity was found in brain, heart, small intestine, lung, and spleen. Female rats exhibited a significantly higher enzyme content than males in liver (0.76 mg. vs. 0.19 mg.) and kidney (0.07 mg. vs. 0.04 mg.), and a tendency to be higher in skeletal muscle (5.5 mg. vs. 4.7 mg.). The significance of this sex difference in terms of total body fat content is discussed.

Chronic intravascular catheterization. A technique for implanting and maintaining arterial and venous catheters in laboratory primates.

Summary A transthoracic surgical technique has been described for implanting and maintaining patent polyvinyl catheters for more than a year at four separate sites in the vascular system of the monkey. These sites include the superior vena cava via the azygos vein, the thoracic aorta via the left subclavian artery, the left pulmonary artery, and the left atrium. Weekly flushing of the catheters has been found to suffice for insuring continued patency.

Psychological and Physiological Responses in Observers of An Atomic Test Shot

This study, conducted during the Atomic Energy Commission 1957 autumn series at the Nevada Test Site, tested two hypotheses. (a) Exposure would produce a physiological adaptation to stress with increased adrenal cortex activity, as indicated by the presence of certain products in the urine and blood. (b ) This exposure would evoke a psychological reaction, as measured by a checklist of stress-indicative words.