Postradiation osteogenic sarcoma of bone and soft tissues. A clinicopathologic study of 66 patients.

Sixty-six patients with well-documented osteogenic sarcomas arising in bones and soft tissues after exposure to x-rays, which represent approximately 5.5 percent of all osteogenic sarcomas registered since 1921 at this institution, were studied. These secondary sarcomas occurred in equal proportion in both sexes, with the sixth decade of life being the most common age.

Active, Irreversible Accumulation of Extreme Levels of H(2)SO(4) in the Brown Alga, Desmarestia.

The brown algae Desmarestia ligulata var. ligulata (Lightf.) Lamour.

Membrane potentials of vallisneria leaf cells and their relation to photosynthesis.

A study has been made of the effects of the inhibitors carbonylcyanide m-chlorophenylhydrazone (CCCP), 3-(3,4-dichlorophenyl)-1,1-dimethyl urea (DCMU), and of anoxia on the light-sensitive membrane potential of Vallisneria leaf cells. The present results are compared with the known effects of these inhibitors on ion transport and photosynthesis (Prins 1974 Ph.D thesis).

Rapid Hormone-induced Hyperpolarization of the Oat Coleoptile Transmembrane Potential.

The effects of the plant growth substances indoleacetic acid (IAA) and fusicoccin on the transmembrane potential of Avena coleoptile cells (at 27-29 C) were studied. Fusicoccin caused hyperpolarization of the membrane potential which started after a lag of less than 20 seconds, and which on average reached -49 mv at an external K(+) concentration of 1 mm and -75 mv at 0.1 mm K(+).

Effect of cyanide on the plasmalemma potential of mnium.

By centrifuging Mnium cuspidatum leaf cells, the cytoplasm can be distinguished from the vacuole and a microelectrode tip can be located unambiguously in the cytoplasm. The site of the electrogenic pump is clearly demonstrated to reside in the plasmalemma as shown by depolarization of the cell electropotential induced by CN(-).

Electrical resistances of corn root segments.

Longitudinal electrical resistances have been measured on 2-centimeter segments of corn (Zea mays L.) roots, cut at varying distances from the root apex. The segment resistances vary from 400 to 100 kilohms per centimeter along the root length (apex to 18 cm), with the maximum occurring in the 2- to 4-centimeter segment, and decreasing thereafter toward the root base.

Electrochemical gradients and k and cl fluxes in excised corn roots.

The compartmental analysis method was used to estimate the K(+) and Cl(-) fluxes for cells of excised roots of Zea mays L. cv. Golden Bantam.

Transmembrane electropotential in barley roots as related to cell type, cell location, and cutting and aging effects.

Transmembrane electropotential difference (PD) was measured in whole roots of barley (Hordeum vulgare L. cvs. Compana and Himalaya).

Primary fibrosarcoma of bone. A clinicopathologic study of 130 patients.

One hundred thirty patients with histologically verified primary fibrosarcoma of bone, unassociated with any pre-existent benign bone condition, were treated at Memorial Sloan-Kettering Cancer Center between 1918 and 1973. This series of cases represents approximately 5% of primary malignant bone tumors treated in our institution. Eighty-nine of the lesions were medullary or central in location, and 41 were periosteal or peripheral.

The effect of cyanide and carbon monoxide on the electrical potential and resistance of cell membranes.

The rapid reduction in cell electropotentials induced by metabolic inhibitors is strong evidence for an electrogenic ion pump. According to Ohm's law, such a depolarization might be explained by a reduction in electric current, I, with unidirectional transport of a given ion, or an increase in permeability (decrease in resistance). With cells of etiolated seedlings of Pisum sativum L.

Higher plant cell membrane resistance by a single intracellular electrode method.

A single intracellular microelectrode technique has been adapted to measure membrane resistance in a higher plant cell. As a direct result of the convenience of this method, which allows relatively long term recordings on a single cell, it has been found that membrane resistance increases for about 30 minutes after cell impalement in Pisum sativum L. cv.

Effects of Filipin and Cholesterol on K Movement in Etiolated Stem Cells of Pisum sativum L.

Filipin, a polyene antibiotic known to induce leakage of materials from various cells, depresses K(+) and NO(3) (-) uptake in etiolated pea epicotyl segments. Filipin concentrations which strongly reduce K(+) influx have little effect on efflux; however, high concentrations enhance K(+) efflux. Filipin has no effect on respiration rates or cell electropotentials; its action is presumed to be on the cell membranes.

Nuclear magnetic resonance studies of sodium and potassium in etiolated pea stem.

Based on nuclear magnetic resonance (NMR) spectroscopy and other evidence, it has been argued that tissues accumulate, and retain, ions in a binding process by a highly structured water-protoplasm system; thus active membrane transport need not be involved. Recent evidence has accounted for the loss of resonance intensity usually found when investigating quadrupolar ions in animal tissue. Using continuous wave NMR spectroscopy, we have examined two quadrupolar ions, Na(+) and K(+), in pea stem cells where about 90% of the ion content is in the largely aqueous vacuoles having a membrane barrier.

Electrical potential differences in cells of barley roots and their relation to ion uptake.

Single cell electropotentials of barley (Hordeum vulgare L., cv. ;Compana') root cortex were measured at different external concentrations of KCl in the presence of Ca(2+).

Evidence for an electrogenic ion transport pump in cells of higher plants.

Cyanide (CN) and dinitrophenol (DNP) rapidly depolarize the cells of oat coleoptiles (Avena sativa L., cultivar Victory) and of pea epicotyls (Pisum sativum L., cultivar Alaska); the effect is reversible.