Publications

1977
Akhtar MS, Verspohl E, Hegner D, Ammon HP. 6-Phosphogluconate/glucose-6-phosphate ratio in rat pancreatic islets during inhibition of insulin release by exogenous insulin. Diabetes. 1977;26 (9) :857-63.Abstract
Inhibition of glucose-stimulated insulin release by exogenous insulin has been demonstrated in pancreatic islets to be associated with a decrease of the NADPH/NADP ratio and the pentose-phosphate cycle activity. Batches of five islets were incubated for 15 and 90 minutes in 1 ml. of KRB buffer with 2 per cent albumin containing 3 mg./ml. glucose and 0, 200, 400, or 800 microU./ml. of rat insulin, and the glucose-6-phosphate (G6P) and 6-phosphogluconate (6PG) contents were determined by enzymatic cycling. In response to a rise in the concentration of insulin, the 6PG/G6P ratio decreased. A close relationship was observed between this decrease of 6PG/G6P ratio and the net insulin release, the absolute rate of glucose oxidation via the pentose phosphate cycle, and the NADPH/NADP ratios measured under similar conditions. The results suggest that exogenous insulin, directly or indirectly, regulates the pentose cycle activity in the pancreatic islets at the G6P dehydrogenase step.
1976
Varthalis S, Pilpel N. Anomalies in some properties of powder mixtures. J Pharm Pharmacol. 1976;28 (5) :415-9.Abstract
Mixtures of lactose and paracetamol and of lactose and oxytetracycline exhibit anomalous properties. The mean particle sizes, tensile strengths and flow properties of the mixtures are not proportionally intermediate between those of the constituents. The results are ascribed to changes that occur in the packing arrangements of the particles. These changes could have practical consequences in monitoring the progress of a mixing operation by measuring apparent particle size and in controlling the properties of granules, capsules and tablets prepared from the mixtures.
Jones JM, Amsbaugh DF, Prescott B. Kinetics of the antibody response to type III pneumococcal polysaccharide. II. Factors influencing the serum antibody levels after immunization with an optimally immunogenic dose of antigen. J Immunol. 1976;116 (1) :52-64.Abstract
When the number of PFC present in the spleen was measured at 24-hr intervals after immunizing with an optimally immunogenic dose of type III pneumococcal polysaccharide (SSS-III), maximal numbers of PFC were attained 4 days after immunization; thereafter, the number of PFC decreased rapidly. By contrast, serum antibody levels, which were measured in the same mice using a Farr test, reached peak values 5 days after immunization and then declined much more slowly than did the number of PFC. Two factors were found to contribute to this disparity. First, experiments conducted with splenectomized mice showed that extrasplenic antibody synthesis, which began between days 3 and 4 after immunization and peaked on days 6 to 7, accounted for nearly one-third of the total amount of serum antibody produced. Second, the average rate of antibody synthesis by PFC increased through day 6 after immunization and then declined. Antigen-antibody dissociation tests showed that the avidity of the serum antibody obtained 4 to 7 days after immunization was the same. Moreover, during the same interval, all the antibody detected by the Farr test was of the IgM class. Thus, a change in avidity or class of immunoglobulin after day 5 did not account for the disparity observed. The clearance rate of antibody injected i.v. into nonimmune and immunized mice was studied. The data obtained indicated that accelerated clearance of antibody was occurring prior to day 3 after immunization; however, after day 3 the antibody clearance rate was constant and was the same as that found when antibody was injected into nonimmune mice. These findings affirmed the results of previous studies showing that treadmill neutralization was not important in determining the serum antibody levels present after immunization with an optimally immunogenic dose of SSS-III.
O'Brien TC. Identification of cariogenic bacteria by fluorescent antibody and other techniques: an international symposium. New York City, April 3-4, 1975. Concluding remarks: the current status of the National Caries Program. J Dent Res. 1976;55 :A207-9.
Chapman LJ, Chapman JP, Daut RL. Schizophrenic inability to disattend from strong aspects of meaning. J Abnorm Psychol. 1976;85 (1) :35-40.
Brown HN, Kelly MJ. Stages of bone marrow transplantation: a psychiatric perspective. Psychosom Med. 1976;38 (6) :439-46.Abstract
Patients undergoing bone marrow transplantation were closely followed by a psychiatric service functioning as part of a multidisciplinary team. A somewhat predictable pattern of psychological reactions to the stress of various stages of the procedure appeared to emerge. Approaches to patient evaluation, typical patient responses, and suggestions for working with these patients and their families are described.
Löw H, Werner S. Effects of reducing and oxidizing agents on the adenylate cyclase activity in adipocyte plasma membranes. FEBS Lett. 1976;65 (1) :96-8.
Horwitz CA, Henle W, Henle G, Polesky H, Wexler H, Ward P. The specificity of heterophil antibodies in patients and healthy donors with no or minimal signs of infectious mononucleosis. Blood. 1976;47 (1) :91-8.Abstract
Over several years sera were collected from 14 heterophil-positive students or patients who did not fulfill minimal hematologic criteria for infectious mononucleosis (I.M.) The specificity of these heterophil reactions for I.M. was investigated by determining antibodies to Epstein-Barr virus-determined antigens, i.e., to viral capsid antigens (VCA), early antigens (EA), and EBV-associated nuclear antigens (EBNA). On the basis of detectable anti-EA and/or the early absence and late emergence of anti-EBNA, four of these 14 individuals showed evidence of a current or very recent primary Epstein-Barr virus infection. The other ten patients showed antibody patterns indicative of Epstein-Barr virus infections in the past, and no firm conclusions could be drawn with regard to the specificity of their heterophil reactions. It was assumed, however, that some represented atypical clinical forms of EBV infection and that timing of specimen collection was a factor in explaining the paucity of Downey cells. In three patients, the absorbed heterophil-positive reactions persisted with little change in titer for at least 22 mo and thus might represent false-positive tests.
Ahmed AE, Anders MW. Metabolism of dihalomethanes to formaldehyde and inorganic halide. I. In vitro studies. Drug Metab Dispos. 1976;4 (4) :357-61.Abstract
Metabolism of dihalomethanes by rat liver cytosol fractions yielded formaldehyde and inorganic halide as products. Loss of metabolic activity resulting from dialysis of the cytosol was restored with glutathione. Cysteine could not substitute for GSH. No other cofactor was found to be required for activity. The optimum conditions for this biotransformation with respect to time, temperature, protein concentration, and pH were determined. Rates of metabolism of dihalomethanes showed the following order: CH2i2 greater than CH2Br2 congruent to CH2BrCi greater than CH2Ci2. Administration of the enzyme inducer, phenobarbital, to rats did not alter this metabolic pathway nor did repeated administration of CH2Br2 or CH2Ci2 change the rate of metabolism. The enzyme catalyzing this reaction was localized in the liver. Compounds known to serve as substrates for various GSH transferases inhibited the reaction as did those capable of interacting with sulfhydryl groups.
PetitClerc C. Quantitative fractionation of alkaline phosphatase isoenzymes according to their thermostability. Clin Chem. 1976;22 (1) :42-8.Abstract
Continuous monitoring of heat denaturation of a mixture of alkaline phosphatase isoenzymes at 60 degrees C and pH 7.5 permits the simultaneous direct identification and quantitation of three isoenzymes: the placental isoenzyme, the L-phenylalanine-sensitive intestinal isoenzyme, and the liver isoenzyme (hepatocytic). The isoenzyme that is principally of bone origin cannot be identified as such without the help of other diagnostic aids and the patient's medical history. All human tissues contain alkaline phosphatase, many organs more than one of the isoenzymes. Liver alkaline phosphatase, which constitutes 40-50% of normal serum alkaline phosphatase activity, was measured in the serum of persons with various liver diseases. Its activity exceeded normal in all types of liver disease; in 80% of cases this increase was accompanied by increased gamma-glutamyl-transferase activity, but the quantitative correlationship (r = 0.54) was not as good as expected if both enzymes come from the same source and are indices of liver dieases. Liver alkaline phosphatase activity increases in the blood early in liver disease, before most liver tests show abnormalities. The other major isoenzyme of normal serum probably represents a mixture of isoenzymes from bone and reticulo-endothelial and vascular tissues, which all contain the same "very heat-labile" alkaline phosphatase. Cord blood and children's sera contain mostly this very heat-labile isoenzyme.
Belaich A, Belaich JP. Microcalorimetric study of the anaerobic growth of Escherichia coli: growth thermograms in a synthetic medium. J Bacteriol. 1976;125 (1) :14-8.Abstract
A microcalorimetric technique was used for studying the growth of Escherichia coli during anaerobiosis. The growth thermograms obtained are complex and the shape of curves is dependent on the hydrogen lyase activity of the cells. Fermentation balances are given for different culture conditions, and simple growth thermograms are obtained when the hydrogen lyase activity is inhibitied.
Prasad N, Bushong SC, North LB, Thornby J. Radiation lethality in the opossum. Radiat Res. 1976;68 (3) :514-7.
Kay J. Complete enzymic digestion of acidic proteins. Int J Pept Protein Res. 1976;8 (4) :379-83.Abstract
Acidic proteins are usually resistant to complete enzymic hydrolysis. The increasing number of "unusual" amino acids, which are unstable to acid hydrolysis, makes it necessary to have a method of enzymic hydrolysis applicable to all proteins. The complete hydrolysis of four acidic proteins by subtilisin plus leucine amino-peptidase plus prolidase followed by carboxypeptidase C, is described. Recoveries of amino acids were in excellent agreement with the expected content from the known sequences.
Deshmukh PV, Kakinuma K, Ameel JJ, Rinehart KL, Wiley PF, Li LH. Letter: Protostreptovaricins I-V. J Am Chem Soc. 1976;98 (3) :870-2.
Guyot JM, Duchevet G. [Transport of a cardiac patient]. Ann Anesthesiol Fr. 1976;17 (5) :599-601.
1975
Peterson DL, Gleisner JM, Blakley RL. Bovine liver dihydrofolate reductase: purification and properties of the enzyme. Biochemistry. 1975;14 (24) :5261-7.Abstract
A purification procedure is reported for obtaining bovine liver dihydrofolate reductase in high yield and amounts of 100-200 mg. A key step in the procedure is the use of an affinity gel prepared by coupling pteroyl-L-lysine to Sepharose. The purified reductase has a specific activity of about 100 units/mg and is homogeneous as judged by analytical ultracentrifugation, polyacrylamide gel electrophoresis, and titration with methotrexate. The products of the first step of Edman degradation indicated a minimum purity of 79%. The reductase has a molecular weight of about 21500 on the basis of amino acid composition and 22100 +/- 300 from equilibrium sedimentation. It is not inhibited by antiserum to the Streptococcus faecium reductase (isoenzyme 2). Unlike the reductase of many other vertebrate tissues, the bovine enzyme is inhibited by mercurials rather than activated and it has a single pH optimum at both low and high ionic strength. However, the position of the pH optimum is shifted and the activity increased by increasing ionic strength. Automatic Edman degradation has been used to determine 34 of the amino-terminal 37 amino acid residues. Considerable homology exists between this region and the corresponding regions of the reductase from S. faecium and from Escherichia coli. This strengthens the idea that this region contributes to the structure of the binding site for dihydrofolate.

Pages