Ability of calcitonins to alter food and water consumption in the rat

Synthetic salmon calcitonin (sCT) given SC (30 MRC U/kg) or ICV (1.4 U, 300 ng) inhibited 24-hr food consumption in the rat by 50–100%. Furthermore, ICV doses of sCT ranging from 75 ng (0.35 U) to 300 ng (1.4 U) lowered both food and water intake in a dose-dependent manner. Use of various forms of CT give an apparent order of potency of salmon>porcine≥human with sCT being at least 40 fold more potent than the mammalian forms. Measurement of food and water intake over a brief (30–90 min) period showed that ICV sCT was effective in reducing food and water consumption regardless of whether it had been given 1, 12, or 23 hr previously. Daily administration of sCT for 5 days caused marked suppression of food and water intake for 2 days; thereafter, consumption returned toward normal, becoming equivalent to vehicle injected controls by day 3 or 4 despite continued daily injections of sCT. The results show that CT can act centrally to modify certain types of behavior and are of special interest since CT-like peptides have been described in the pituitary and hypothalamus and since CT receptors have been reported in hypothalamic and other brain regions.     

Nuclear peptides from calf liver: large scale isolation and fractionation; control of gene expression in cell-free systems, and inhibition of growth of cells in culture

DNA and nuclear RNA fractions contain small peptides (mol. wt. 600-1500) attached noncovalently. A large scale isolation procedure was developed for the extraction of such peptides directly from the lysed nuclei. Further purification and fractionation was performed with the chromatography on Sephadex, silica gel and H.P.L.C. C18 reverse phase columns. H.P.L.C. fractionation yielded eleven peaks. The peptides are rich in serine, glycine, alanine and acidic amino acids. They do not contain sulfur-containing amino acids. Only occasionally tyrosine, phenyalanine, histidine, arginine, and very moderate amount of lysine are found. These peptides are active in inhibiting gene expression in cell-free systems and incorporation of labeled thymidine in L 1210 murine leukemic cell culture. Thorough and exhaustive analysis demonstrated that the isolated peptides are not degradative products of histone or nonhistone chromosomal proteins.     

Plasma carnitine and cholesterol levels in monkeys and pigeons: species/breed differences and the influence of gender and diet.

1. Total plasma carnitine and cholesterol were studied in two breeds of pigeon and four species of sub-human primates. 2. The levels of plasma carnitine and cholesterol differed within species and between species and were influenced by diet and gender. 3. In the animals studied, pigeons had the highest levels of plasma carnitine (greater than 120 nM/ml) and Squirrel monkeys (Saimiri sciureus) had the lowest levels (ca. 10 nM/ml). 4. Linear regression analysis of plasma carnitine and cholesterol in the monkeys and pigeons indicated no strong correlation between these parameters.     

A rapid,inexpensive, quantitative technique for the analysis of two-dimensional electrophoretograms

We describe a rapid, reproducible, and relatively inexpensive method for quantitative analysis of two-dimensional gel radiofluorograms. The equipment required includes a mediumresolution black and white video camera for data acquisition, a video digitizing circuit for data translation, and a microcomputer for data analysis. The system described can also be used to quantitate protein- or DNA-stained one- or two-dimensional gels or chromatograms.     

Local xenogeneic graft-vs-host reaction: a practical assessment of T cell function among cancer patients.

The local xenogeneic graft-vs-host reaction (XGVHR) was used as a practical bioassay to assess T lymphocyte function and immunocompetence among cancer patients. Positive XGVHR was found in 99.5% of normal donors, 70% of cancer patients with early stage disease, and 30% of cancer patients with metastatic disease (p less than 0.001). A minimum of 4.5 x 10(6) immunocompetent T lymphocytes are necessary in order to elicit a positive XGVHR. Negative reactions among cancer patients are characterized by the lack of edema fluid accumulation and the appearance of the most basophils at the test site. This suggests that insufficient amounts of lymphokines are being released by the incompetent T lymphocytes, whereas the host is capable of mounting a rejection reaction as evidenced by the appearance of the basophils. Preliminary evidence suggests that the immunologic defect detected by the XGVHR cannot be corrected by monocyte depletion. The identification of putative suppressor T cell subsets may bear immunotherapeutic implications in the future.