Serum factors releasing serotonin from normal platelets: relation to the manifestations of systemic lupus erythematosus

In 13 patients with systemic lupus erythematosus, globulin fractions of sera from serial bleedings were assayed for the induction of serotonin release from normal platelets. Releasing activity appeared at some time in the sera of seven patients, five of whom had episodes of thrombocytopenia. Conversely, only one patient manifested thrombocytopenia without the occurrence of serotonin releasing activity at any time. In three patients with episodes of thrombocytopenia, increases in serotonin releasing activity temporally coincided with drops in platelet count. These data show that levels of circulating platelet serotonin releasing factor(s) vary in the course of systemic lupus erythematosus and these variations may be inversely related to the platelet count in particular patients.     

Regulation of acetylcholine synthesis: does cytoplasmic acetylcholine control high affinity choline uptake?

When brain synaptosomes are obtained from animals that have been injected intravenously with [2H4]choline 1 minute before being killed, their high affinity [3H] choline uptake is correlated inversely with their acetylcholine content and directly with the rate at which they synthesize [2H4]acetylcholine. The control of such choline uptake by the cytoplasmic acetylcholine concentration is proposed as a mechanism regulating acetylcholine synthesis in cholinergic nerve terminals.     

Analysis of a large pedigree with elliptocytosis, multiple lipomatosis, and biological false-positive serological test for syphilis

Elliptocytosis, multiple lipomatosis, and biological false-postive serological test for syphilis (BFPSTS) were found in a single individual. One hundred eighty relatives were tested for the three diseases: 74 were typed for seven blood group antigens, and 58 were typed for four electrophoretic enzyme markers. Likelihood analysis of the pedigree data confirmed independent dominant inheritance for elliptocytosis and lipomatosis. BFPSTS appears dominant, but the analysis was inconclusive. No linkages were found between any disease gene and any marker gene. Two female pedigree members with BFPSTS developed systemic lupus erythematosus, a finding in agreement with the previously described association. The analysis did not lead to any conclusions about the causal relationship between the two traits.     

Exercise tolerance at 4 and 6 ATA

Seven normal male subjects performed 5-min bicycle exercise ranging from 50-100% maximum oxygen uptake at 4 ATA and three were also studied at 6 ATA. At all pressures, the subjects breathed 0.2 ATA O2 plus nitrogen. All subjects were able to perform maximum work at all pressures. No pressure-dependent variations in heart rate, O2 uptake, or CO2 output were noted. At both 4 and 6 ATA, ventilation was decreased at exercise levels greater than 80% maximum O2 uptake. The magnitude of the decrease was not great, however, and signified only minor CO2 retention. In some instances exercise ventilation closely approached the 15-S maximum breathing capacity and these subjects noted severe dyspnea, possibly due to dynamic compression of large airways. In three subjects, respiratory frequency was measured as well as minute ventilation; this relationship did not change with depth. Subjects performing heavy exercise at 6 ATA noted disturbances of consciousness, presumably due to N2 narcosis.     

The effects of zinc and copper salts on Cyprinus carpio and Ctenopharyngodon idellus

The effects of zinc and copper salts on the survival of the two species of freshwater fish, common carp, Cyprinus carpio, and grass carp, Ctenopharyngodon idellus, were investigated. It was discovered that the levels of tolerance to the concentration of the metals were species-specific. Cyprinus carpio was found to be more susceptible to copper, whereas Ctenopharyngodon idellus was more susceptible to zinc. In general, copper was more toxic than zinc, as revealed by the survival times. The body and the gills of dead fish seemed to be covered by a veil-like film which looked like coagulated mucus and which was formed by the heavy-metal ions reacting with some constituents of the mucus and which was formed by the heavy-metal ions reacting with some constituents of the mucus secreted by the gill. The histopathological assessment of the gill and liver of Cyprinus carpio was also carried out. Particles were observed around the gills of the dead fish treated with zinc and copper salts, although no other major changes were found in the gill. Several histopathological changes were observed in the livers, including the presence of particles. The symptoms of the liver suggested that the internal injury was also an important feature of the intoxicants.     

The influence of baking fuel on residues of polycyclic aromatic hydrocarbons and heavy metals in bread

The influence of fuel type used to bake bread on the spectrum and concentrations of some polycyclic aromatic hydrocarbons and heavy metals in baked bread was assessed. Bread samples were collected from different bakeries operated by either electricity, solar, mazot or solid waste and their residue content of PAHs and heavy metals was assessed. The total concentration of PAHs detected in mazot, solar, solid waste and electricity operated bakeries had an average of 320.6, 158.4, 317.3 and 25.5 μg kg⁻¹, respectively. Samples collected from mazot, solar and solid waste operated bakeries have had a wide spectrum of PAHs, in comparison to that detected in bread samples collected from electricity operated bakeries. Lead had the highest concentrations in the four group of bread samples, followed by nickel, while the concentrations of zinc and cadmium were the least. The concentration of lead detected in bread samples produced from mazot, solar, solid waste and electricity fueled bakeries were 1375.5, 1114, 1234, and 257.3 μg kg⁻¹, respectively. Estimated daily intake of PAHs based on bread consumption were 48.2, 28.5, 80.1, and 4.8 μg per person per day for bread produced in bakeries using mazot, solar, solid waste and electricity, respectively. Meanwhile, the estimated daily intake of benzo (a) pyrene were 3.69, 2.65, 8.1, and 0.81 μg per person per day for bread sample baked with mazot, solar, solid waste and electricity, respectively. The daily intake of lead, based on bread consumption was 291, 200.5, 222, and 46.31 μg per person per day for bread sample baked with mazot, solar, solid waste and electricity, respectively. The present work has indicated the comparatively high level of daily intake of benzo (a) pyrene and lead in comparison to levels reported from many other countries and those recommended by international regulatory bodies. It is probable that residues detected in bread samples are partially cereal-borne but there is strong evidence that the process of baking and the gases emitted are responsible for most of the contamination load.     

Structure of the 3'-hairpin of the TYMV pseudoknot: preformation in RNA folding

The solution structure of an RNA-hairpin present in the pseudoknot, which is found at the 3'-terminus of turnip yellow mosaic virus genomic RNA, has been solved by nuclear magnetic resonance spectroscopy. The loop, which contains the sequence 5'-GGGUCA-3', was found to be highly structured and, contrary to expectations, does not attain its stability through GA or GC base pair formation but by triple interactions between the tilted adenosine and the minor groove sides of the first two guanosines. Interestingly, a very similar conformation was found for the cognate pseudoknot, implying that the 3'-hairpin is preformed for folding into a pseudoknotted structure. These findings suggest a mechanism of 'predetermined-fit' as a principle in RNA folding.