Epstein-Barr virus transformation of human B lymphocytes despite inhibition of viral polymerase.

Epstein-Barr virus transformed human lymphocytes despite the presence of up to 500 microM acyclovir [9-(2-hydroxyethoxymethyl)guanine], a viral DNA polymerase inhibitor. The transformed cells contained multiple Epstein-Barr virus genome copy numbers. Functional viral DNA polymerase is probably not required for cell transformation and the initial amplification of the viral genome.     

Andromonoecy and fruit set in three genera of the Proteaceae

It has been suggested by some authors that the low fruit to flower ratio in some Proteaceae is due to andromonoecy, while others, looking particularly at Banksia , have not been able to find evidence for male flowers in the inflorescences. Stirlingia latifolia, Xylomelum occidentals and X. angustifolium are clearly andromonoecous, while no evidence for this condition could be found in Brabejum stellatifoliutn. Production of fertile fruit is related to andromonoecy in Xylomelum and S. latifolia but not in Brabejum. It is unlikely that all-encompassing solutions will be found to what initially seem to be widespread traits in the family, especially in regard to pollination biology, as the genera in the family occupy widely different environments and have very diverse ecological ranges.     

On the Rotation of Canonical Solutions

Some points of CLIFF /KRUS 's important rotation procedure are criticized. This result in the definition of simple structure of canonical solutions, the use of STEWART /LOVE 's redundancy index as a measure of common variance, and two new rotation procedures (HAKSTIAN 's modified varimax rotation, separate rotation of both sets). The objects of rotation should be the (intraset) loadings.     

Properties of purified colchicine-binding protein from a cultured carrot cell extract

Colchicine-binding protein (CBP) was purified from a cultured carrot cell extract by DEAE-Sephacel, phosphocellulose and Sephadex G200 column chromatographies. The purified CBP separated into three bands on SDS-polyacrylamide gel electrophoresis. One of them reacted with a monoclonal antibody against chick brain alpha-tubulin and the other two with that against beta-tubulin. Colchicine-binding activity of the purified protein was enhanced by tartrate and inhibited little by an excess of podophyllotoxin. It decayed following first order kinetics, but was more stable than the CBP in the crude extract. The binding constant of the purified CBP for colchicine was 0.57 microM-1 and the number of binding sites of colchicine per mg protein was about 2 nmol. This binding constant is about ten times lower than that of porcine brain tubulin under identical conditions.     

Absent aldosterone response to metoclopramide in patients with high spinal cord transection: evidence that metoclopramide stimulates aldosterone secretion through central pathways

This study evaluates dopaminergic regulation of aldosterone secretion in 6 patients with high spinal cord transections. Administration of the dopamine antagonist metoclopramide resulted in a marked rise in plasma aldosterone and 18-hydroxycorticosterone levels in 12 normal individuals, but no change in plasma levels of these zona glomerulosa corticosteroid products in spinal cord patients. Spinal cord transected patients also did not have the rise in plasma renin activity that was observed in normals following metoclopramide administration. Basal levels of aldosterone, 18 hydroxycorticosterone, corticosterone and renin activity as well as the aldosterone responses to graded dose infusion of adrenocorticotropin were similar in the spinal cord patients and the normals. These data suggest that dopaminergic regulation of adrenal zona glomerulosa corticosteroid and renal renin secretion is absent in patients with high spinal cord transections, suggesting that intact neural pathways from the central nervous system are necessary for metoclopramide stimulation of aldosterone and renin secretion in men. Since basal plasma aldosterone levels were normal in spinal cord transected patients, it appears that the absence of dopaminergic control does not result in elevated secretion.     

Changes in the size and shape of the synaptic vesicles in the sensorimotor cortex of the rat brain in the initial phases of kindling

The sensorimotor area of rat cerebral cortex was subjected to repeated electrical stimulation at 10-min intervals, with resultant formation and progressive lengthening of self-sustained after-discharges (SSAD). One and 60 min after the third SSAD ended, we carried out an electron microscopy morphometric analysis of the agranular synaptic vesicles in type I synapses (after Gray) in the second cortical layer of the homotopic area of the unstimulated hemisphere. One minute after the seizure ended, 5.8% enlargement of the synaptic vesicles compared with the control was demonstrated in zone II of the synapse (0.1-0.2 micron from the active zone of the synapse). Neither the size nor the shape of the synaptic vesicles in the other parts of the synaptic apparatus altered. Sixty min after the seizure ended, a 5.5% enlargement of the synaptic vesicles in zone I (0.0-0.1 micron) and a 5.4% enlargement of those in zone II was found. The synaptic vesicles in zone I in the experimental animals were more oval than in the controls. Our findings support the vesicular theory and testify that hyperfunction, up to temporary exhaustion of the synaptic apparatuses, produces a change in the transmitter content of the synaptic vesicles. A raised amount of transmitter in the synaptic vesicles near the active zone could be one of the factors responsible for continued hyperexcitability of the tissue one hour after the seizure had ended. The results likewise support the concept of two mechanisms of synaptic vesicle formation, and hence of the existence of two different vesicle populations.