Willed action and the prefrontal cortex in man: a study with PET.

We used positron emission tomography to contrast changes in cerebral blood flow associated with willed and routine acts. In the six tasks used, volunteers had to make a series of responses to a sequence of stimuli. For the routine acts, each response was completely specified by the stimulus. For the willed acts, the response was open-ended and therefore volunteers had to make a deliberate choice. Willed acts in the two response modalities studied (speaking a word, or lifting a finger) were associated with increased blood flow in the dorsolateral prefrontal cortex (Brodmann area 46). Willed acts were also associated with decreases in blood flow, but the location of these decreases was modality dependent.     

Characterization of canine intestinal cholecystokinin-58 lacking its carboxyl-terminal nonapeptide. Evidence for similar post-translational processing in brain and gut.

An antibody raised against a synthetic cholecystokinin (CCK) analog, (1-27)-(CCK)-33, corresponding to the midregion of CCK-58, detected immunoreactivity in intestinal extracts which eluted between the positions of CCK-33/39 and CCK-58 on high performance liquid chromatography. This peak, lacking carboxyl-terminal cholecystokinin immunoreactivity, was purified by reverse phase and cation-exchange chromatographies. Amino acid, mass spectral, and microsequence analysis established that it was the amino-terminal desnonapeptide fragment of cholecystokinin-58, (1-49)-CCK-58. It was demonstrated further that CCK-58 has less biological activity than CCK-8, suggesting that the amino terminus either sterically hindered the ability of CCK-58 to exert its biological activity or that its amino terminus acted at another site to inhibit release of amylase from rat pancreatic acini. The desnonapeptide of CCK-58 by itself had no biological activity, nor did it affect CCK-8-stimulated amylase release from isolated rat pancreatic acini, suggesting that the amino terminus shields the carboxyl terminus from expressing its biological activity. Its presence in intestine suggests that it is released into the circulation where it could be detected by midregion antibodies. The presence of high proportions of (1-49)-CCK-58 indicates that most CCK-8 is directly derived from CCK-58. Its occurrence in brain and intestine indicates similar processing for procholecystokinin in both tissues.     

Desert Truffles of the Australian Outback: Ecology,Ethnomycology, and Taxonomy

Desert Truffles of the Australian Outback: Ecology, Ethnomycology, and Taxonomy. The Aborigines of central Australia have traditionally used desert truffles as food. Truffle hunting in the desert requires substantial ecological knowledge, as truffles occur sporadically and only with adequate and properly distributed rainfall as well as the presence of necessary soil conditions and mycorrhizal hosts. Truffles are hunted primarily by women, who look for cracks or humps in the soil caused by expansion of the truffles, which are then extracted with digging sticks. The truffles are typically eaten raw or baked or roasted in ashes. Seven truffle species are recorded from the Australian Outback, including three that have been only recently described.     

Look who's talking: nuclear receptors in the liver and gastrointestinal tract

The Nuclear Receptors in Liver and Digestive Diseases research workshop was held in Rockville, Maryland, on November 7 and 8, 2007, under the auspices of the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health. Over 130 researchers from around the world gathered to assess the pathophysiology of nuclear receptors in the liver and gastrointestinal tract and to explore their potential use as therapeutic targets. This review covers some of the highlights of the meeting, including important areas of future investigation.     

Sperm whale depredation of sablefish longline gear in the northeast Pacific Ocean

Interactions between marine mammals and fisheries include competition for prey (catch), marine mammal entanglement in fishing gear, and catch removal off fishing gear (depredation). We estimated the magnitude of sperm whale depredation on a major North Pacific longline fishery (sablefish) using data collected during annual longline surveys. Sperm whale depredation occurs while the longline gear is off‐bottom during retrieval. Sperm whales were observed on 16% of longline survey sampling days, mostly (95% of sightings) over the continental slope. Sightings were most common in the central and eastern Gulf of Alaska (98% of sightings), occasional in the western Gulf of Alaska and Aleutian Islands, and absent in the Bering Sea. Longline survey catches were commonly preyed upon when sperm whales were present (65% of sightings), as evidenced by damaged fish. Neither sperm whale presence (P = 0.71) nor depredation rate (P = 0.78) increased significantly from 1998 to 2004. Longline survey catch rates were about 2% less at locations where depredation was observed, but the effect was not significant (P = 0.34). Estimated sperm whale depredation was <1% of the annual sablefish longline fishery catch off Alaska during 1998 to 2004.     

3-(1',1'-Dimethylbutyl)-1-deoxy-delta8-THC and related compounds: synthesis of selective ligands for the CB2 receptor

The synthesis and pharmacology of 15 1-deoxy-delta8-THC analogues, several of which have high affinity for the CB2 receptor, are described. The deoxy cannabinoids include 1-deoxy-11-hydroxy-delta8-THC (5), 1-deoxy-delta8-THC (6), 1-deoxy-3-butyl-delta8-THC (7), 1-deoxy-3-hexyl-delta8-THC (8) and a series of 3-(1',1'-dimethylalkyl)-1-deoxy-delta8-THC analogues (2, n = 0-4, 6, 7, where n = the number of carbon atoms in the side chain-2). Three derivatives (17-19) of deoxynabilone (16) were also prepared. The affinities of each compound for the CB1 and CB2 receptors were determined employing previously described procedures. Five of the 3-(1',1'-dimethylalkyl)-1-deoxy-delta8-THC analogues (2, n = 1-5) have high affinity (Ki = < 20 nM) for the CB2 receptor. Four of them (2, n = 1-4) also have little affinity for the CB1 receptor (Ki = > 295 nM). 3-(1',1'-Dimethylbutyl)-1-deoxy-delta8-THC (2, n = 2) has very high affinity for the CB2 receptor (Ki = 3.4 +/- 1.0 nM) and little affinity for the CB1 receptor (Ki = 677 +/- 132 nM).     

A LIGHT- AND ELECTRON-MICROSCOPIC STUDY OF PRIMARY HETEROGENEITY IN THE EGGS OF TWO BROWN ALGAE

The mature eggs of Zonaria farlowii and Dictyota binghamiae exhibit a distinctively symmetrical arrangement of organelles. In mature oogonia plastids occur in two groups in the central region of the cell and vacuoles of several types are arranged in peripheral layers. Before the mature egg is released, an amorphous “mucilage layer” developes inside the wall of the oogonium. After fertilization the plastids become uniformly distributed. When the eggs of Zonaria develop parthenogenetically the primary heterogeneity is retained. The symmetrical arrangement of membranes seen in the oocytes of these plants may represent an organizing system that influences cytodifferentiation and perhaps subsequent embryology.     

Alteration of life span of mice chronically exposed to 2.45 GHz CW microwaves

Female CD 1 mice were exposed from the thirty-fifth day of age for the remainder of their lives to 2.45 GHz, CW-microwave radiation at a power density of 3 or 10 m W/cm² (SAR = 2.0 or 6.8 W/kg). Exposures took place 1 h/day, 5 day/week in an anechoic chamber at an ambient temperature of 22 °C and a relative humidity of 50%. There were 25 animals in each exposure group, and an equal number of controls were concurrently sham exposed. The average life span of animals exposed at 10 mW/cm² was significantly shorter than that of sham-exposed controls (572 days vs. 706 days; P = .049; truncation >20%). In contrast, the average lifespan of the animals exposed at 3 mW/cm² was slightly, but not significantly, longer (738 days) than that of controls (706 days). © 1994 Wiley-Liss, Inc.

1 This article is a US Government work and, as such, is in the public domain in the United States of America.

     

Monitor peptide binding sites are expressed in the rat liver and small intestine.

125I-monitor peptide binding was performed using frozen sections of the rat liver and gut and visualized using autoradiography. Saturable binding was observed in unidentified single cells in the liver and in the mucosa of the small intestine. Epidermal growth factor (EGF) and GTPgammaS did not inhibit 125I-monitor peptide binding indicating that the binding sites are not EGF receptors or G protein-coupled receptors. The liver binding site exhibited an affinity 3.7-4.4-fold higher than those in the small intestine. It has been established that intraluminal monitor peptide releases cholecystokinin from the small intestine. The present results indicate that monitor peptide may also have liver associated functions.     

REPRODUCTION IN ZONARIA FARLOWII. I. GAMETOGENESIS,SPOROGENESIS, AND EMBRYOLOGY1

The brown alga Zonaria farlowii which exhibits an alternation of isomorphic generations has been found to be a particularly suitable organism for a comparative study of game to gene sis, sporogenesis, and embryonic development. The germinations of the zygote and spore have been compared and found to be similar. The development of the oogonium and sporangium has been studied with the light and electron microscopes, in an attempt to discern ontogcnetical similarities or differences. The timing and periodicity of oogenesis and sporogenesis were found to differ: oogonial development requires a lunar month from the time of its initiation to the time of egg release which occurs around the first quarter of the moon, whereas the sporangium does not follow this periodicity. The development of the spore embryos and zygotic embryos is essentially the same. It appears that the difference between the 2 phases of the life cycle exists only in the later stages of oogenesis and sporogenesis. These differences continue in the egg until fertilization, after which the zygote has the same cytoplasmic configuration as the spore. It is also notable that during release of the spore it must increase in size considerably since before germination begins it has attained the size of the egg.