Acid-Soluble Deoxynucleotides and DNA Synthesis in Growing Yeast after X-Irradiation, II. Synthesis of Deoxynucleoside Tri- and Monophosphates in Synchronized and Asynchronously Growing Cells

1974 ◽  
Vol 29 (5-6) ◽  
pp. 272-282 ◽  
Author(s):  
Hans Eckstein ◽  
Sybille Ahnefeld ◽  
Karin Albietz-Loges
Keyword(s):  
Dna Replication ◽  
Radiation Effects ◽  
Phosphorus Uptake ◽  
Specific Radioactivity ◽  
Phosphorus Compounds ◽  
Pronounced Increase ◽  
Precursor Pool ◽  
Soluble Phosphorus ◽  
X Irradiation ◽  
Quantitative Changes

The behaviour of acid-soluble DNA precursors in synchronized and asynchronously growing yeast after X-irradiation is investigated by labeling techniques with 32Pi and by enzymic estimation. In prelabeled synchronized growing cells, radioactivity associated with deoxynucleoside triphosphates increases to maximum values shortly before each DNA replication, followed by a drastic decrease during S-phase. Radioactivity associated with monophosphates fluctuates, too, but with an opposite rhythm. These fluctuations apparently reflect quantitative changes of the DNA precursor pool during a cell cycle, as judged from the following findings: 1. Acid-soluble phosphorus is augmented stepwise. 2. "Specific" radioactivity from acid-soluble phosphorus compounds decreases steadily, indicating a continuous dilution of the labeled phosphorus pool with "cold" phosphorus. 3. Radioactivity associated with ribonucleotides fluctuates, too, but with a divergent rhythm. In X-irradiated synchronice growing yeast, the fluctuations of the deoxynucleotide-associated 32P are disturbed only little. Maximum values appear nearly at the same time as in the control, they decrease to minor values even if DNA augmentation is delayed. This decrease is less drastic, however, than that during DNA replication in unirradiated yeast, yielding a slightly increased aver­ age label per generation time. At the same sime a rapid augmentation of monophosphate label is observed. A pronounced increase of deoxynucleotide-32P is seen with X-irradiated asynchronously growing yeast, pointing to distinct radiosensitivities of the DNA/DNA precursor system in different cell stages. Neither 32P-fluctuations nor 32P-accumulation during DNA delay can be explained by cor­ responding observations with acid-soluble phosphorus or with ribonucleotide pools. Studies on 32P-incorporation also exclude radiation effects on cellular phosphorus uptake. Enzymic estimations of the deoxynucleoside triphosphate pools from asynchronously growing yeast rather exhibit a considerable increase of these substances during the radiation-induced delay of DNA augmentation. This accumulation of DNA precursors probably is caused by undisturbed synthesis, but reduced incorporation into DNA. The possible role of DNA repair in this system is discussed.

scholarly journals The turnover of myelin phospholipids in the adult and developing rat brain

1971 ◽  
Vol 123 (5) ◽  
pp. 683-693 ◽  
Author(s):  
F. B. Jungalwala ◽  
R. M. C. Dawson
Keyword(s):  
Turnover Rate ◽  
Specific Radioactivity ◽  
Substantial Part ◽  
Adult Rats ◽  
Myelin Membrane ◽  
Precursor Pool ◽  
Soluble Phosphorus ◽  
Myelin Fraction ◽  
Small Pool ◽  
Developing Rat

1. Inorganic [32P]phosphate, [U-14C]glycerol and [2-14C]ethanolamine were injected into the lateral ventricles in the brains of adult rats, and the labelling of individual phospholipids was followed over 2–4 months in both a microsomal and a highly purified myelin fraction. 2. All the phospholipids in myelin became appreciably labelled, although initially the specific radioactivities of the microsomal phospholipids were somewhat higher. Eventually the specific radioactivities in microsomal and myelin phospholipids fell rapidly at a rate corresponding to the decline of radioactivity in the acid-soluble pools. 3. Equivalent experiments carried out in developing rats with [32P]phosphate administered at the start of myelination showed some persistence of phospholipid labelling in the myelin, but this could partly be attributed to the greater retention of 32P in the acid-soluble phosphorus pool and recycling. 4. It is concluded that a substantial part of the phospholipid molecules in adult myelin membranes is readily exchangeable, although a small pool of slowly exchangeable material also exists. 5. A slow incorporation into or loss of labelled precursor from myelin phospholipids does not necessarily give a good indication of the rate of renewal of the molecules in the membrane. As presumably such labelled molecules originate by exchange with those in another membrane site (not necessarily where synthesis occurs) it is only possible to calculate the turnover rate in the myelin membrane if the behaviour of the specific radioactivity with time of the phospholipid molecules in the immediate precursor pool is known.

Solid, slightly soluble phosphorus compounds as nutrient source in activated sludge treatment of forest industry wastewaters

1997 ◽  
Vol 35 (2-3) ◽  
pp. 131-138 ◽  
Author(s):  
Pirjo-Riitta Rantala ◽  
Hannu Wirola
Keyword(s):  
Activated Sludge ◽  
The Other ◽  
Phosphorus Compounds ◽  
Forest Industry ◽  
Phosphorus Concentration ◽  
Nutrient Source ◽  
Sludge Treatment ◽  
Grain Sizes ◽  
Soluble Phosphorus ◽  
The Mean

The aim of the study was to determine if solid, slightly soluble compounds can be used as nutrient source in activated sludge treatment plants instead of liquid phosphoric acid. Four different solid materials were tested in lab-scale solubility tests to find compounds which are least soluble. Two materials were chosen for further studies: apatite and raw phosphate. The use of apatite and raw phosphate as nutrient source was studied in lab-scale activated sludge reactors along with a control reactor where phosphorus was added in liquid form. The phosphorus dosage, measured as elementary phosphorus, was the same for all three reactors. The reactors were fed with pre-clarified chemi-thermomechanical pulp mill (CTMP) wastewater. There were no significant differences in the reductions of organic matter between the three reactors. The mean effluent concentration of total phosphorus was 3 mg P/l in the control reactor and less than 1 mg P/1 in the other two reactors. The soluble phosphorus concentration was more than 2 mg P/l in the control reactor and less than 0.5 mg P/l in the other two. Apatite was an even better nutrient source than raw phosphate. Further lab-scale tests were conducted using two different grain sizes of apatite. No significant differences were found between the studied grain sizes (<0.074 mm and 0.074 mm-0.125 mm). Apatite was then used in full-scale at a CTMP-mill two different times. The experiments showed that the mean concentrations of phosphorus can be reduced radically by using apatite as a nutrient source instead of liquid phosphorus. Solid phosphorus compounds are a viable alternative to reduce the phosphorus load from forest industry wastewater treatment plants.

scholarly journals The dynamics of acid-soluble phosphorus compounds in the course of winter and spring wheat germination under various thermic conditions. Part II. Labile phosphorus after hydrolysis of the acid-soluble fraction

2015 ◽  
Vol 24 (2) ◽  
pp. 297-308
Author(s):  
A. Barbaro
Keyword(s):  
Low Temperature ◽  
Phosphorus Content ◽  
Soluble Fraction ◽  
Phosphorus Compounds ◽  
Labile Phosphorus ◽  
Soluble Phosphorus ◽  
Germination Temperature ◽  
Wheat Germination ◽  
Labile P ◽  
Hydrolysis Of

The changes in labile phosphorus compounds content during germination of wheat were investigated. These compounds were determined in acid-soluble germ extracts separated into fractions according to the solubility of their barium salts. Low germination temperature was found to raise the labile phosphorus content in the fraction of insoluble barium salts. If we assume that labile P of this fraction consisted mainly of adenosinedi- and triphosphates, it would seem that the rise, in the ATP and ADP level under the influence of low temperature may be essential for initiating flowering in winter varieties.

scholarly journals The metabolism of polyphosphoinositides in hen brain and sciatic nerve

1969 ◽  
Vol 111 (2) ◽  
pp. 157-165 ◽  
Author(s):  
A. Sheltawy ◽  
R. M. C. Dawson
Keyword(s):  
Sciatic Nerve ◽  
Previous Investigation ◽  
Relative Rate ◽  
Specific Radioactivity ◽  
Brain Slices ◽  
Soluble Phosphorus ◽  
Ethanolamine Plasmalogen ◽  
32P Incorporation ◽  
The Brain

1. The distribution of individual phospholipids was determined in hen brain and compared with that in sciatic nerve obtained in a previous investigation. Sciatic nerve is more enriched in the myelinic phospholipids ethanolamine plasmalogen, phosphatidylserine and sphingomyelin, but it contains relatively less triphosphoinositide, and much less diphosphoinositide, than the brain. 2. The course of incorporation of intraperitoneally injected 32P into the acid-soluble phosphorus, phosphoinositides and total phospholipids of hen brain and sciatic nerve was followed. Although the maximum specific radioactivity in sciatic nerve of acid-soluble phosphorus is 4·5 times, and that of triphosphoinositide six times, that in the brain, the relative rate of triphosphoinositide phosphorus synthesis per gram of brain is three times that in sciatic nerve. 3. Administration of the demyelinating agent tri-o-cresyl phosphate to hens has no significant effect on the amounts or the rate of 32P incorporation into the total phospholipids of the sciatic nerve. However, the rate of incorporation of 32P into triphosphoinositide, although not its concentration, is raised from the first day after administration of the drug and remains thus 13 and 23 days later. 4. The incorporation of 32P into polyphosphoinositides of hen brain slices in vitro was studied. The recovery of triphosphoinositide from the slices is markedly increased in the presence of EDTA, although the rate of incorporation of 32P is unaffected. The incorporation of 32P is dependent on the presence of Mg2+ and Ca2+ in the medium, and is decreased when Na+ is replaced with K+ or cholinium ions.

scholarly journals A quantitative analysis of adverse radiation effects following Gamma Knife radiosurgery for arteriovenous malformations

2015 ◽  
Vol 123 (4) ◽  
pp. 945-953 ◽  
Author(s):  
Or Cohen-Inbar ◽  
Cheng-Chia Lee ◽  
Zhiyuan Xu ◽  
David Schlesinger ◽  
Jason P. Sheehan
Keyword(s):  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Radiation Effects ◽  
Late Onset ◽  
Gamma Knife Radiosurgery ◽  
Volumetric Analysis ◽  
Institutional Review ◽  
Complete Obliteration ◽  
Quantitative Changes

OBJECT The authors review outcomes following Gamma Knife radiosurgery (GKRS) of cerebral arteriovenous malformations (AVMs) and their correlation to postradiosurgery adverse radiation effects (AREs). METHODS From a prospective institutional review board–approved database, the authors identified patients with a minimum of 2 years of follow-up and thin-slice T2-weighted MRI sequences for volumetric analysis. A total of 105 AVM patients were included. The authors analyzed the incidence and quantitative changes in AREs as a function of time after GKRS. Statistical analysis was performed to identify factors related to ARE development and changes in the ARE index. RESULTS The median clinical follow-up was 53.8 months (range 24–212.4 months), and the median MRI follow-up was 36.8 months (range 24–212.4 months). 47.6% of patients had an AVM with a Spetzler-Martin grade ≥ III. The median administered margin and maximum doses were 22 and 40 Gy, respectively. The overall obliteration rate was 70.5%. Of patients who showed complete obliteration, 74.4% developed AREs within 4–6 months after GKRS. Late-onset AREs (i.e., > 12 months) correlated to a failure to obliterate the nidus. 58.1% of patients who developed appreciable AREs (defined as ARE index > 8) proceeded to have a complete nidus obliteration. Appreciable AREs were found to be influenced by AVM nidus volume > 3 ml, lobar location, number of draining veins and feeding arteries, prior embolization, and higher margin dose. On the other hand, a minimum ARE index > 8 predicted obliteration (p = 0.043). CONCLUSIONS ARE development after radiosurgery follows a temporal pattern peaking at 7–12 months after stereotactic radiosurgery. The ARE index serves as an important adjunct tool in patient follow-up and outcome prediction.

Studies of acid-soluble phosphorus compounds in genetically pure lines of Avena fatua with different dormancy characteristics

1982 ◽  
Vol 60 (10) ◽  
pp. 2099-2104 ◽  
Author(s):  
J. C. Jain ◽  
W. A. Quick ◽  
A. I. Hsiao
Keyword(s):  
Inverse Correlation ◽  
Avena Fatua ◽  
Significant Decline ◽  
Phosphorus Compounds ◽  
Relative Depth ◽  
Uniform Field ◽  
Wild Oat ◽  
Dormancy Breaking ◽  
Soluble Phosphorus ◽  
Pure Lines

Seven genetically pure lines of wild oat selections of known dormancy characteristics were grown under uniform field conditions. Acid-soluble phosphorus components were determined in the dry seeds, in the imbibed seeds, and in imbibed seeds with dormancy-breaking treatments. No significant correlation between dormancy level and acid-soluble phosphorus composition was established for any component other than inorganic phosphorus (Pi). In dry caryopses Pi varied from 5 to 10% of the acid-soluble fraction. A highly significant inverse correlation was found between levels of Pi in the dry caryopsis and the relative depth of dormancy of the wild oat selection considered. The effect of imbibition on Pi level varied with depth of dormancy. Intact seeds of nondormant lines imbibed for 52 h showed a significant decline in Pi prior to coleorhiza protrusion from the dehulled caryopsis. More deeply dormant lines of Avena fatua (pure lines Anderson 51, Anderson 474, or Crop Science 40) required up to 10 days of incubation for significant drops in Pi to appear, while the most dormant lines (pure line Montana 73 and Idaho) did not evidence significant decline in Pi even after 10 days of incubation. The increase in Pi level associated with coleorhiza protrusion could be produced in the imbibed dormant lines by piercing them with a fine needle, by treating with gibberellic acid (GA3), or by a combination of the two treatments. The combination of piercing and GA3 treatment was much more effective than either treatment alone.

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