Biochemical identification of thymosin alpha-1: its phylogenetic distribution and evolutionary implications

1. Thymosin alpha-1, like reactivity, was found in several different species (insects, crab, protozoan, fungus and bacteria) by radioimmunoassay and immune fluorescence and as an extracellular product from the bacterial genus Mycobacterium. 2. Biochemically, thymosin alpha-1 has been isolated from combined crab visceral and nervous tissue by reverse phase HPLC. 3. The identification of thymosin alpha-1 in lower life forms suggests a more generalized exocrine origin in unicellular organisms prior to the development of the immune system or exocrine differentiation.     

The effect of glucose on the synthesis of prostaglandins by the renal papilla of the rat in vitro.

Renal pappillae from rats were incubated in vitro. The release of prostaglandin by this tissue was found to be inversely related to the glucose concentration of the buffer. Estimates of prostaglandin release were determined by a rat stomach strip bioassay, and in some instances, gas-chromatography and mass spectrometry. When incubated in the presence of C14-arachidonic acid, the specific activity of prostaglandins E2 and F2 alpha released by the tissue was lower at the lower glucose concentration. Provision of 625 micrograms/ml of exogenous arachidonic acid in the buffer obliterated the effect of glucose on prostalglandin release. These data indicate that increasing amounts of glucose suppresses prostaglandin synthesis in the renal papilla of the rat, and that the mechanism of this phenomenon is related to the release of arachidonic acid from its storage pools in tissue lipids.     

Metabolism of bufotenine-2′-14C in human volunteers

The major ultimate metabolites of bufotenine-2′-¹⁴C in two volunteers have been identified and quantitated in the urine after intravenous administration of doses of 0.2 mg and 1 mg (10 μc/mg). Both subjects excreted over 90% of the ¹⁴C within 12 hours. Most of this was in the form of 5-hydroxyindoleacetic acid (68% and 74%). Only small amounts of bufotenine itself were excreted (1% and 6%). The remaining radioactive materials in the urine were not identified.     

A fossil earthworm embryo (Oligochaeta) from beneath a Late Bronze Age midden at Potterne, Wiltshire, UK

An embryonic earthworm (Oligochaeta: Lumbricidae), preserved with part of its cocoon wall by calcium phosphate mineralization, has been extracted from a deposit beneath a Late Bronze Age midden in southern England. The structure, possible identity and significance of the specimen are discussed.     

Effects of chorda tympani nerve anesthesia on taste responses in the NST

Human clinical and psychophysical observations suggest that the taste system is able to compensate for losses in peripheral nerve input, since patients do not commonly report decrements in whole mouth taste following chorda tympani nerve damage or anesthesia. Indeed, neurophysiological data from the rat nucleus of the solitary tract (NST) suggests that a release of inhibition (disinhibition) may occur centrally following chorda tympani nerve anesthesia. Our purpose was to study this possibility further. We recorded from 59 multi- and single- unit taste-responsive sites in the rat NST before, during and after recovery from chorda tympani nerve anesthesia. During anesthesia, average anterior tongue responses were eliminated but no compensatory increases in palatal or posterior tongue responses were observed. However, six individual sites displayed increased taste responsiveness during anesthesia. The average increase was 32.9%. Therefore, disinhibition of taste responses was observed, but infrequently and to a small degree in the NST At a subset of sites, chorda tympani-mediated responses decreased while greater superficial petrosal-mediated responses remained the same during anesthesia. Since this effect was accompanied by a decrease in spontaneous activity, we propose that taste compensation may result in part by a change in signal-to-noise ratio at a subset of sites.