DIABETOGENIC ACTION OF HUMAN GROWTH HORMONE Synthesis and Activity of C-terminal Fragments

Three peptides corresponding to the C-terminal region of human growth hormone have been synthesized by the solid-phase method: HGH-(177–191), HGH-(178–191) and HGH-(179–191). The diabetogenic activities of these synthetic peptides are reported. The data indicate that extension of HGH-(179–191) at its NH₂-terminus is required for in vivo activity. The reduced and S-carbamido-methylated form of HGH-(177–191) was also active, indicating that the disulphide bond is possibly not a prerequisite for biological activity.     

The Normal Development of the Lymphoid Mass in the Golden Hamster and its Relationship to the Effects of Thymectomy

A study of lymphoid organ sections and imprints of normal hamsters fromfetal to adult state revealed a sequential pattern of organ structure and growth.The thymus developed an adult structure by 1 week, maximum size at 6 weeks.The mesenteric lymph node had an adult structure by 4 weeks, the spleen by 6weeks, with an accelerated growth of both organs between 6 to 8 weeks. Thegrowth and development of the peripheral lymphoid organs appears to beunder thymic control until the attainment of a "critical peripheral lymphoidmass." This appears capable of functioning independently of thymic control.Thymectomy is effective in producing lymphoid atrophy with resultant immunosuppression and wasting disease only if performed prior to the attainmentof the "critical peripheral lymphoid mass."

Submitted on February 6, 1964 Accepted on July 26, 1964     

Specificity of pepsin-catalyzed peptide bond synthesis

The rates of the pepsin-catalyzed synthesis of oligopeptides of the general type A-Phe-Leu-B by the condensation of A-Phe-OH with H-Leu-B have been determined by means of analytical high performance liquid chromatography. Variation of the A group led to large changes in the initial rates of the condensation reaction, and the effect of such changes was found to be similar to that previously found for the secondary specificity of pepsin in the hydrolysis of oligopeptide substrates. Replacement of the Phe and Leu residues of A-Phe-OH or H-Leu-B by other amino acid residues gave relative rates of synthesis in accord with the known primary specificity of the hydrolytic action of pepsin. Partially-acetylated pepsin, which exhibits enhanced hydrolytic activity, also catalyzed the condensation reaction more effectively. The results are discussed in relation to the potential utility and limitations of pepsin as a catalyst in the preparative synthesis of oligopeptides and to the problem of the mechanism of its action.     

Increased Activity of Some Folic Acid Enzyme Systems in Infectious Mononucleosis

Increased levels of activity for the formate activating enzyme and N⁵,N¹⁰-methylene FH₄ dehydrogenase have been found in the leukocytes from patients with infectious mononucleosis; in addition dihydrofolic reductase, anenzyme not found in mature circulating leukocytes, has been detected in infectious mononucleosis cells. Glucose-6-phosphate dehydrogenase activity isless in infectious mononucleosis leukocytes than in normal leukocytes.

These findings are similar to the results obtained in acute and chronic myelogenous leukemia and indicate that the leukocytes seen in infectious mononucleosis have the enzymatic apparatus associated with synthesis of DNA.

Submitted on November 6, 1961 Accepted on January 12, 1962     

Postnatal Parental Concerns: The First Six Weeks of Life

The postnatal needs of parents from the infant's birth to the first physician visit remain largely unmet. This project explored these needs through the abstraction and coding of questions normally phoned to the health care provider during this period. The differential effects of infant sex, age, and parent parity on the contents of these questions were also explored. Findings suggest that parents of first or male infants have a much higher rate of questions. Several striking interactive effects were observed and are presented.     

Lymphangiography in Tuberculous Lymphadenitis

A rare lymphangiographic feature of tuberculous lymphadenitis in a patient who was investigated for generalised lymphadenopathy is presented.     

Problems in the Measurement of Putative Serum Immune Complexes by the Method of Beaumont

ABSTRACT: A methodological investigation of the procedure used by Beaumont et al for measuring a “serum immune complex” precipitated by 25% ammonium sulfate and alleged to contain an ethynyl-estradiol binding immunoglobulin has found major problems with reproducibility and with the correlation of total protein as measured by the Lowry method and the IgG content as determined by a specific nephelometric procedure.