Rooperol, an inhibitor of cytokine synthesis, decreases the respiratory burst in human and rat leukocytes and macrophages

Luminol-enhanced chemiluminescence was measured in fresh whole human blood, or human neutrophils isolated from heparinized blood, human alveolar macrophages and rat alveolar macrophages stimulated with bacterial endotoxin (LPS). Tetraacetate esters of rooperol, a dicatechol showing anticytokine activity, added to cells simultaneously with LPS inhibited the respiratory burst. The effective concentrations of rooperol were in the range of 1-10 muM depending on cell type and corresponded well with inhibition of nitric oxide production by rat alveolar macrophages. Thus rooperol may reduce some effects of excessive phagocytic activity and inflammatory reaction but by quenching free radicals production may also diminish the resistance to bacterial infections.     

The carboxy-terminal two-thirds of the cowpea chlorotic mottle bromovirus capsid protein is incapable of virion formation yet supports systemic movement.

Previous investigations into recombination in cowpea chlorotic mottle bromovirus (CCMV) resulted in the recovery of an unusual recombinant virus, 3-57, which caused a symptomless infection of cowpeas but formed no detectable virions. Sequence analysis of cDNA clones derived from 3-57 determined that mutations near the 5' terminus of the capsid protein gene introduced an early translational termination codon. Further mutations introduced a new in-frame start codon that allowed translation of the 3' two-thirds of the capsid protein gene. Based on the mutations observed in 3-57, wild-type CCMV clones were modified to determine if the carboxyl two-thirds of the capsid protein functions independently of the complete protein in long-distance movement. Analysis of these mutants determined that while virion formation is not required for systemic infection, the carboxy-terminal two-thirds of the capsid protein is both required and sufficient for systemic movement of viral RNA. This indicates that the CCMV capsid protein is multifunctional, with a distinct long-distance movement function in addition to its role in virion formation.     

Characterization of predominant bacteria from the colons of normal and dysenteric pigs.

Bacterial populations adherent to the mucosa of the proximal colons of weaned, healthy pigs were compared with populations from pigs with dysentery induced by inoculation with a culture of Treponema hyodysenteriae. Isolates (136) representative of the predominant flora adherent to colonic epithelia of normal pigs and isolates (162) from pigs with dysentery were cultured anaerobically on a rumen fluid-based medium and characterized. Most (71%) of the isolates from colonic epithelia of normal pigs were gram positive, whereas 88% of the epithelia-associated isolates from pigs with dysentery were gram negative. The geometric mean of colony counts was 5.7 X 10(7)/cm2 of colonic tissue from three normal pigs and 7.7 X 10(8)/cm2 from four pigs with dysentery. A number of isolates obtained from contents of the lumens of normal pigs with dysentery were also characterized. Comparison of isolates from epithelial tissue and from contents of the lumens of the same pig indicated that these populations were different. Our results indicate that physiological changes that occur in the colons of pigs with dysentery are accompanied by marked changes in the microbial populations in the colons. The factors which regulate the population changes are not yet understood.     

Effects of low-chloride solutions on action potentials of sheep cadiac purkinje fibers

The rapid repolarization during phase 1 of the action potential of sheep cardiac purkinje fibers has been attributed to a time- and voltage-dependent chloride current. In part, this conclusion was based on experiments that showed a substantial slowing of phase 1 when larger, presumably impermeant, anions were substituted for chloride in tyrode’s solution. We have re- examined the electrical effects of low-chloride solutions. We recorded action potentials of sheep cardiac purkinje fibers in normal tyrode’s solution and in low-chloride solutions made by substituting sodium propionate, acetylglycinate, methylsulfate, or methanesulfonate for the NaCl of Tyrode’s solution. Total calcium was adjusted to keep calcium ion activity of test solutions equal to that of control solutions. Propionate gave qualitatively variable results in preliminary experiments; it was not tested further. Low-chloride solutions made with the other anions gave much more consistent results: phase 1 and the notch that often occurs between phases 1 and 2 were usually unaffected, and the action potential duration usually increased. The only apparent change in the resting potential was a transient 3-6 mV depolarization when low-chloride solution was first admitted to the chamber, and a symmetrical transient hyperpolarization when chloride was returned to normal. If a time- and voltage-dependent chloride current exists in sheep cardiac purkinje fibers, our results suggest that it plays little role in generating phase 1 of the action potential.     

Biologic and chemical characterization of HLA antigens in human serum.

HLA antigens of both the A and B loci were shown to be associated with the high density lipoprotein fraction of serum prepared by ultracentrifugal flotation. HLA-A9 antigens were purified 100-fold with essentially complete recovery by a simple procedure of high density lipoprotein preparation involving precipitation with polyanions and ultracentrifugal flotation. The purified lipid-associated antigen was immunogenic since it elicited the formation of cytotoxic xenoantibodies in rabbits. Serum HLA-A9 antigens were found by immunoprecipitation and gel electrophoresis to consist of a 45,000 m.w. heavy chain associated with beta2-microglobulin. The size of the HLA-lipid complex (less than 190,000 m.w.) and of the HLA-deoxycholate complex (less than 102,000 m.w.) suggests that HLA antigens are shed into plasma as a complex of a single HLA molecule and a single beta2-microglobulin chain, associated with boundary lipid.     

Effect of nutritionally induced liveweight differences on ovulation rates and the population of ovarian follicles in ewes

Differential feeding prior to the onset of the breeding season resulted in mean liveweight differences of 12 kg in two groups of Romney ewes. This difference was maintained while ovulation rates and the population of externally visible ovarian follicles were measured. The ovulation rate at first oestrus was significantly higher in the high liveweight group but there was no difference between groups thereafter. High liveweight ewes had consistently higher mean follicle scores at all stages of the oestrous cycle. Mean follicle score was lower following the third oestrus than following first oestrus (P < 0.01).     

Sesquiterpenes of thalloid liverworts of the genera Conocephalum,Lunularia, Metzgeria and Riccardia

Thalloid liverworts of orders Metzgeriales and Marchantiales elaborate essential oils distinguishable from those of the Jungermanniales by the absence of β-barbatene and anastreptene. Riccardia sinuata elaborates a novel tricyclic exomethylene sesquiterpene of as yet undetermined structure. Conocephalum conicum elaborates cadinene-type sesquiterpenes. β-Cadinene from the latter species is clearly enantiomeric to the same product from vascular plants.