Adenine induced granulocytosis in the rabbit.

Peripheral blood specimens from rabbits injected parenterally with physiological saline, adenine sulfate and guanine sulfate were examined for white blood cell count changes. A significant leukocytosis occurred within forty-eight hours only after adenine sulfate administration. A differential analysis revealed the increase was in the heterophil (pseudoeosinophil, amphophil) population. A mild lymphopenia was noted. There were no clear cut trends in the eosinophil, basophil and monocyte populations. No leukocyte morphological changes were found on peripheral blood smears.     

Inhibition of protein degradation in isolated rat hepatocytes

1. Isolated parenchymal cells were prepared by collagenase perfusion of livers from fed rats that had been previously injected with [³H]leucine to label liver proteins. When these cells were incubated in a salts medium containing glucose, gelatin and EDTA, cellular integrity was maintained over a period of 6h. 2. Cells incubated in the presence of 2mm-leucine to minimize radioactive isotope reincorporation released [³H]leucine into the medium at a rate accounting for the degradation of 4.5% of the labelled cell protein per h. 3. Degradation of [³H]protein in these cells was inhibited by insulin and by certain amino acids, of which tryptophan and phenylalanine were the most effective. 4. Protein degradation was decreased by several proteinase inhibitors, particularly those that are known to inhibit lysosomal cathepsin B, and by inhibitors of cell-energy production. 5. Ammonia inhibited degradation, but only at concentrations above 1.8mm. Aliphatic analogues of ammonia were effective at lower concentrations than was ammonia. 6. High concentrations of ammonia inhibited degradation by 50%. The extent of this inhibition could not be increased further by the addition of the cathepsin B inhibitor leupeptin, which by itself inhibited degradation by approx. 30%. 7. The sensitivity of proteolysis in isolated hepatocytes to these various inhibitory agents is discussed in relation to their possible modes of action.     

Studies on the mode of action of calciferol: Biological activity of 1α,24R,25-trihydroxyvitamin D3 in the chick

The biological activity of 1α,24R,25-trihydroxyvitamin D₃ [1α,24R,25(OH)₃D₃] was elevated in comparison to the hormonally active form of vitamin D₃, 1α,25-dihydroxyvitamin D₃ [1α,25(OH)₂D₃], in the rachitic chick in terms of its ability to (a) stimulate intestinal calcium absorption, (b) mobilize bone calcium, (c) induce intestinal calcium binding protein, (d) modulate the level of enzyme activity of the renal 25-OH-D₃-1-hydroxylase system, and (e) interact with the intestinal cystosol-chromatin receptor system for the 1α,25(OH)₂D₃ receptor system. In each of these assays, the relative ratio of activity of 1α,24R,25(OH)₃D₃ to 1α,25(OH)₂D₃was (a) 25–50, (b) ca. 20, (c) 10, (d) 50, and (e) 36%, respectively.     

Morphine and Cocaine Exert Common Chronic Actions on Tyrosine Hydroxylase in Dopaminergic Brain Reward Regions

We studied levels of tyrosine hydroxylase immunoreactivity and phosphorylation state in the ventral tegmental area (VTA) and nucleus accumbens (NAc) in an effort to understand better the mechanisms by which these brain reward regions are influenced by opiates and cocaine. In the VTA, chronic, but not acute, administration of either morphine or cocaine increased levels of tyrosine hydroxylase immunoreactivity by 30-40%, with no change observed in the relative phosphorylation state of the enzyme. In the NAc, chronic, but not acute, morphine and cocaine treatments decreased the phosphorylation state of tyrosine hydroxylase, without a change in its total amount. In contrast, morphine and cocaine did not regulate tyrosine hydroxylase in the substantia nigra or caudate/putamen, brain regions generally not implicated in drug reward. Morphine and cocaine regulation of tyrosine hydroxylase could represent part of a common biochemical basis of morphine and cocaine addiction and craving.     

Arboriculture in the Mussau Islands,Bismarck Archipelago

The Mussau Islanders of the Bismarck Archipelago in northeastern Papua New Guinea cultivate 26 indigenous tree species both for food and non-food uses in tree gardens surrounding the villages. Several trees which volunteer in these arboriculture zones are also tended and encouraged. I present ethnobotanical information on methods of cultivation, how and when the trees are harvested, preparation and use. The tree crop zone has a random spatial distribution overall, but some species within the zone are aggregated spatially. This clumping is related to the restricted habitat requirements of certain species, as well as individual species ’ reproductive traits. Coconut is the most frequent species in the arboriculture zone and is randomly distributed. Vertical stratification is attributable to the presence of a distinct herb layer and a subcanopy stratum of maturePandanus spp. The stratification of some species pairs results from the deliberate planting of subcanopy trees next to canopy trees. The introduction of exotic garden species and the increasing availability of western packaged foods is changing the composition of traditional Mussau Islands tree gardens.     

Regional bioelectric properties of porcine airway epithelium.

Ion transport properties of pulmonary small airway epithelia are poorly understood. To characterize these properties, airways were excised from anesthetized pigs. Transepithelial potential difference (PD) and conductance were measured in five airway regions: trachea (T, 7.9 +/- 0.2 mm diam), mainstem bronchi (MB, 5.5 +/- 0.2 mm diam), large bronchi (LB, 1.69 +/- 0.12 mm diam), small bronchi (SB, 0.70 +/- 0.06 mm diam), and bronchioles (BR, 0.25 +/- 0.05 mm diam). T and MB were mounted in Ussing-type chambers, and LB, SB, and BR were cannulated with pipettes and perfused. PDs of control tissues were -9.7 +/- 0.8 mV (T), -4.0 +/- 0.5 mV (MB), -4.3 +/- 1.0 mV (LB), -4.5 +/- 0.4 mV (SB), and -1.5 +/- 0.4 mV (BR), lumen negative. Amiloride significantly (P < 0.05) inhibited PDs by 25-70% in all airway regions and decreased conductance 17-33% in all regions except LB where a 10% increase was observed. Bumetanide significantly reduced the amiloride-insensitive PD 54-62% in all regions except BR. Bumetanide had little effect on conductance in T, SB, and BR, but conductance was increased in MB and LB. All airways except the smallest BR significantly hyperpolarized when the solution that bathed the lumen was replaced with Cl(-)-free solution. In bronchioles, hyperpolarization by luminal Cl(-)-free solution was inversely related to fractional inhibition of PD with amiloride but directly related to lumen diameter. These results suggest that 1) porcine tracheas, bronchi, and bronchioles actively absorb Na+, and 2) secretion of Cl- may occur in all airway regions except small bronchioles.     

Artemia monica cyst production and recruitment in Mono Lake,California, USA

Annual egg production was determined for Artemia monica in Mono Lake, California, from 1983 to 1987. Annual oviparous (overwintering cyst) production was 3 and 7 million cysts m^–2 yr^–1 in 1986 and 1987, respectively, as measured by in situ sediment traps. Cyst production for the entire five year period was calculated using Artemia census data and inter-brood duration derived from mixolimnetic temperature. These estimates ranged from 2 to 5 million cysts m^–2 yr^–1. This method underestimated annual production by 30%, when compared to estimates using sediment traps. Cyst production was similar during 1983–1986 and showed a significant increase in 1987, which was due primarily to a larger reproductive population later in the year. Recruitment into the adult populations of the following spring ranged between 1.4 to 3.2%. Overall abundance of this generation reflected the patterns in annual cyst production. Compensatory effects must operate on the second generation of each year, since summer populations were similar in all years despite differences in cyst production.     

Lamellar bodies of cultured human fetal lung: content of surfactant protein A (SP-A), surface film formation and structural transformation in vitro

Lamellar bodies were isolated from dexamethasone and T3-treated explant cultures of human fetal lung, using sucrose density-gradient centrifugation. We examined their content of surfactant apoprotein A (SP-A), and their ability to form surface films and to undergo structural transformation in vitro. SP-A measured by ELISA composed less than 2% of total protein within lamellar bodies; this represented, as a minimum estimate, a 2-12-fold enrichment over homogenate. One- and two-dimensional gel electrophoresis also suggested that SP-A was a minor protein component of lamellar bodies. Adsorption of lamellar bodies to an air/water interface was moderately rapid, but accelerated dramatically upon addition of exogenous SP-A in ratios of 1:2-16 (SP-A:phospholipid, w/w). Similar adsorption patterns were seen for lamellar bodies from fresh adult rat and rabbit lung. Lamellar bodies incubated under conditions that promote formation of tubular myelin underwent structural rearrangement only in the presence of exogenous SP-A, with extensive formation of multilamellate whorls of lipid bilayers (but no classical tubular myelin lattices). We conclude that lamellar bodies are enriched in SP-A, but have insufficient content of SP-A for structural transformation to tubular myelin and rapid surface film formation in vitro.