FURTHER OCCURRENCES OF SPENCERITES FROM THE MIDDLE PENNSYLVANIAN OF KANSAS AND ILLINOIS

New specimens of Spencerites moorei add knowledge of its sporophylls and method of sporangial attachment. The sporophyll consists of a slender pedicel which expands at its distal end into a fleshy, peltate, diamond-shaped head which bears a presumably fleshy lamina. The sporangium is attached through most of its length to the adaxial surface of the pedicel rather than distally as in S. insignis. It is suggested that the distal attachment shown in S. insignis may be derived through a phyletic shift from the pedicellate position. Additional specimens of Spencerites provisionally assigned to S. majusculus are also recorded. The spores are bilateral, monolete, and shaped like quadrants of a sphere. Two prominent wings extend along the two contact faces and the monolete mark is prominently raised, thus imparting a three-winged appearance to the spore. The axis consists of an exarch protostele and a cylinder of thick-walled outer cortex.     

Evaluation of mixed cell types and 5-iodo-2'-deoxyuridine treatment upon plaque assay titers of human enteric viruses

Four continuous cell lines, BGM, L-132, HEL-299, and RD, were compared both when cultured separately and as mixtures for use in plaque assay titrations of human adenovirus 1 and six human enterovirus serotypes. The effect of incubating these cell cultures in media containing 5-iodo-2'deoxyuridine (IDU) prior to inoculation with virus was also studied. The use of mixed-cell cultures revealed cell line-dependent synergistic effects as well as inhibitory effects. These effects were strongly virus dependent. In particular, enterovirus 69 did not form plaques on any of the four cell lines when cultured independently. However, it did form plaques on nearly all of the cell lines when cultured as mixtures. Contrary to this effect, when BGM cells were used in combination with the other cell lines, plaque counts for adenovirus 1 were greatly reduced. The effect of IDU pretreatment was also virus and cell line specific and enabled some viruses to form plaques on cell lines when they otherwise would not. Overall, IDU pretreatment resulted in an approximate twofold increase in plaque titers over those obtained without treatment.     

Influence of mevalonate kinase on studies of the MgATP-dependent inactivator of 3-hydroxy-3-methylglutaryl coenzyme A reductase

The nature of the MgATP-dependent inactivator of 3-hydroxy-3-methylglutaryl coenzyme A reductase has been studied. Several observations suggest that reductase inactivator preparations from both microsomes and cytosol possess mevalonate kinase activity. (1) Reductase inactivator (reductase kinase) activity copurified with mevalonate kinase activity. (2) Inactivator activity was inhibited by geranyl pyrophosphate and farnesyl pyrophosphate, known to be potent inhibitors of mevalonate kinase. (3) Addition of an excess of mevalonate completely prevented inhibition of reductase activity. (4) Formation of phosphomevalonate fully accounted for the decreased amount of mevalonate formed in the presence of inactivator and MgATP. (5) When reductase activity was measured by NADPH oxidation, no inhibition was observed. Clearly, the presence of mevalonate kinase in reductase inactivator preparations can lead to misinterpretations concerning whether reductase activity is regulated by phosphorylation-dephosphorylation. In this paper, we present several methods and approaches which can be used to critically evaluate this possibility.     

Evaluation of mixed cell types and 5-iodo-2'-deoxyuridine treatment upon plaque assay titers of human enteric viruses.

Four continuous cell lines, BGM, L-132, HEL-299, and RD, were compared both when cultured separately and as mixtures for use in plaque assay titrations of human adenovirus 1 and six human enterovirus serotypes. The effect of incubating these cell cultures in media containing 5-iodo-2'deoxyuridine (IDU) prior to inoculation with virus was also studied. The use of mixed-cell cultures revealed cell line-dependent synergistic effects as well as inhibitory effects. These effects were strongly virus dependent. In particular, enterovirus 69 did not form plaques on any of the four cell lines when cultured independently. However, it did form plaques on nearly all of the cell lines when cultured as mixtures. Contrary to this effect, when BGM cells were used in combination with the other cell lines, plaque counts for adenovirus 1 were greatly reduced. The effect of IDU pretreatment was also virus and cell line specific and enabled some viruses to form plaques on cell lines when they otherwise would not. Overall, IDU pretreatment resulted in an approximate twofold increase in plaque titers over those obtained without treatment.     

The ecology of the scorpion Euscorpius flavicaudis in England

A large colony of Euscorpius flavicaudis was studied at Sheerness Docks, Isle of Sheppey, Kent. It was probably established in the late nineteenth century. The scorpions inhabit cracks in the dockyard perimeter wall where the mortar pointing has crumbled away. They are nocturnal, "sit-and-wait", generalist predators. They are extremely sedentary: females leave their cracks fewer than 10 times per year; males are more active as they become vagrant prior to the mating season, which occurs in summer. Marked adults were resighted at intervals of over a year and the distance scorpions moved between resightings was not proportional to the interval. The number of scorpions seen per night was influenced by temperature, amount of rainfall and phase of the moon. In winter, the scorpions retreated far into the wall and, by doing so, reduced the risk of suffering mortality due to cold. During this time, they were seldom active. In general, this species does not behave in any way that can be correlated with living in a temperate rather than a desert area. This illustrates the extreme adaptability of scorpions.     

Rapid exercise-induced changes in PGC-1alpha mRNA and protein in human skeletal muscle

The mRNA of the nuclear coactivator peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) increases during prolonged exercise and is influenced by carbohydrate availability. It is unknown if the increases in mRNA reflect the PGC-1alpha protein or if glycogen stores are an important regulator. Seven male subjects [23 +/- 1.3 yr old, maximum oxygen uptake (Vo(2 max)) 48.4 +/- 0.8 ml.kg(-1).min(-1)] exercised to exhaustion ( approximately 2 h) at 65% Vo(2 max) followed by ingestion of either a high-carbohydrate (HC) or low-carbohydrate (LC) diet (7 or 2.9 g.kg(-1).day(-1), respectively) for 52 h of recovery. Glycogen remained depressed in LC (P < 0.05) while returning to resting levels by 24 h in HC. PGC-1alpha mRNA increased both at exhaustion (3-fold) and 2 h later (6.2-fold) (P < 0.05) but returned to rest levels by 24 h. PGC-1alpha protein increased (P < 0.05) 23% at exhaustion and remained elevated for at least 24 h (P < 0.05). While there was no direct treatment effect (HC vs. LC) for PGC-1alpha mRNA or protein, there was a linear relationship between the changes in glycogen and those in PGC-1alpha protein during exercise and recovery (r = -0.68, P < 0.05). In contrast, PGC-1beta did not increase with exercise but rather decreased (P < 0.05) below rest level at 24 and 52 h, and the decrease was greater (P < 0.05) in LC. PGC-1alpha protein content increased in prolonged exercise and remained upregulated for 24 h, but this could not have been predicted by the changes in mRNA. The beta-isoform declined rather than increasing, and this was greater when glycogen was not resynthesized to rest levels.