scholarly journals ULTRACENTRIFUGATION STUDIES ON THE ELEMENTARY BODIES OF VACCINE VIRUS

1938 ◽  
Vol 68 (4) ◽  
pp. 607-627 ◽  
Author(s):  
Joseph E. Smadel ◽  
Edward G. Pickels ◽  
Theodore Shedlovsky
Keyword(s):  
Sedimentation Rate ◽  
Vaccine Virus ◽  
Normal Rate ◽  
Buffer Solution ◽  
Buffer Solutions ◽  
Original Volume ◽  
Sucrose Solutions ◽  
Rate Of Sedimentation

Ultracentrifugal studies of the CL dermal strain of vaccine virus warrant the following conclusions: 1. When suspended in increasing concentrations of sucrose, glycerol, or urea solutions, elementary bodies of vaccinia show variations in sedimentation rate which indicate changes in the density or size of the particles. For a given change in the density of the medium these changes are smallest with sucrose and most marked with urea. The normal rate of sedimentation of Paschen bodies may be restored by resuspending them in dilute buffer solution. 2. The density of elementary bodies of vaccinia suspended in dilute buffer solutions is estimated to be 1.16 gm. per cc. Higher values for the density are found if the particles are suspended in solutions containing sucrose, glycerol, or urea. In 53 per cent sucrose, for example, the density is 1.25 gm. per cc. 3. Paschen bodies appear to be quite permeable to water and urea, less so to glycerol, and only slightly, if at all, to sucrose. 4. The increased density of the elementary bodies of vaccinia in sucrose solutions may be accounted for by an osmotic extraction of water from the particles. On this basis the water which can be thus extracted corresponds to at least a third of the original volume of the particles.

scholarly journals ELECTROPHORETIC STUDIES ON ELEMENTARY BODIES OF VACCINIA

1940 ◽  
Vol 72 (5) ◽  
pp. 511-521 ◽  
Author(s):  
Theodore Shedlovsky ◽  
Joseph E. Smadel
Keyword(s):  
Moving Boundary ◽  
Serum Proteins ◽  
Vaccine Virus ◽  
Rabbit Serum ◽  
Normal Rabbit Serum ◽  
Buffer Solution ◽  
Buffer Solutions ◽  
Heat Stable ◽  
Heat Stable Antigen ◽  
Sufficient Magnitude

Electrophoretic studies were made on vaccine virus, collodion particles, and glass particles suspended in 0.01 molar buffer solutions at pH 7.9, in which the moving boundary method was used. In some experiments, uncoated particles were used; in others, particles were coated with proteins and then resuspended in the buffer solution after a washing; in still others, an excess of protein which had been used to coat the particles was included in the buffer medium. Streaming boundaries were obtained with all dilute suspensions of particles in solutions containing no soluble protein instead of the flat ones usually observed with the Tiselius moving boundary technique. This boundary artifact was suppressed by maintaining a density gradient of sufficient magnitude in association with the moving boundary to counteract the tendency of endosmotic flow. This was done partially by increasing the concentration of the particles in the suspensions, and almost completely by retaining an excess of soluble-coating substance in the solutions containing the particles. The mobility of elementary bodies of vaccinia corresponds to that found for the heat-stable (S) antigen. This value was not altered by drying, heating, ether extraction, or simple washing, but was materially increased by treatment with the surface active detergent (duponol) which presumably altered the nature of the surface of the virus particles. Collodion particles coated with the heat-stable antigen of vaccinia had the same mobility as elementary bodies under comparable conditions. Glass particles coated with normal rabbit serum moved at the rate of albumin, the fastest serum component in the buffer solutions used. However, both collodion particles and vaccine virus moved at a somewhat slower rate when they were similarly coated and measured in the presence of an excess of serum in the solutions. This was probably due to adsorption of a small amount of one of the slower components (globulin) of rabbit serum on the surface of the particles. Simple washing after treatment seemed to remove the coating of serum proteins, at least in part, from both collodion particles and elementary bodies of vaccinia.

Rumination in sheep. III. Experimentally induced variations on the circadian pattern of rumination

1965 ◽  
Vol 16 (4) ◽  
pp. 649 ◽  
Author(s):  
GR Pearce
Keyword(s):  
Extended Period ◽  
High Protein ◽  
Circadian Pattern ◽  
Buffer Solution ◽  
Buffer Solutions ◽  
Experimentally Induced

The circadian (24-hr) pattern of rumination of caged sheep was found to be affected: (a) by the administration of a roughage ration per fistulam; (b) by the emptying of the rumen and the subsequent return of the rumen contents; (c) by the emptying of the rumen and the replacement of the contents by a buffer solution plus roughage. The period during which no rumination occurred following feeding was progressively shortened when increasing proportions of a ration of oaten chaff and lucerne chaff were administered per fistulam. The effect was much reduced when high protein sheep cubes were added to the chaff ration. The removal of the rumen contents after voluntary feeding and then their immediate return to the rumen tended to cause an early commencement of rumination. When the rumen contents were "pasteurized" before return, however, rumination did not occur for an extended period afterwards. When the rumen contents were replaced with buffer solutions plus roughage, variable rumination responses occurred. In one instance apparently uninhibited rumination resulted.

scholarly journals THE PROPERTIES OF MAMMALIAN STRIATED MYOFIBRILS ISOLATED BY AN ENZYMATIC METHOD

1950 ◽  
Vol 91 (6) ◽  
pp. 655-664 ◽  
Author(s):  
Armin F. Schick ◽  
George M. Hass
Keyword(s):  
Ionic Strength ◽  
Potassium Chloride ◽  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Potassium Phosphate ◽  
Microscopic Structure ◽  
Buffer Solution ◽  
Buffer Solutions ◽  
Alkaline Side ◽  
Fresh Frozen

A new method for the isolation of large numbers of individual myofibrils from fresh mammalian skeletal and cardiac muscle has been described. Purification of isolated myofibrils was accomplished by differential centrifugation of fresh frozen sections of muscle which had been mechanically agitated after exposure for 30 to 45 minutes at 0°C. to the action of a dilute solution of trypsin in a phosphate buffer solution with a pH of 7.0 and an ionic strength of 0.25. Isolated skeletal myofibrils of the rabbit and man have similar constant solubility properties. They dissolve in an aqueous mixture of 0.5 N potassium chloride and 0.03 N sodium bicarbonate, giving viscous solutions which exhibit conspicuous birefringence of flow. They are soluble in buffer solutions (ionic strength 0.15) on the acid side of pH 4 and alkaline side of pH 10. If the ionic strength of potassium phosphate buffer solutions is increased to 0.5 or if the ionic strength of phosphate-borate buffer solutions is increased to a similar value by addition of potassium chloride, the isolated myofibrils become soluble at neutrality. Hence, it is possible, first to isolate the myofibrils and then dissolve them without deviating appreciably from physiologic ranges of pH. The extent to which myofibrils are modified by the conditions imposed by the method of isolation is unknown. There is no significant change in microscopic structure or optical birefringence. Furthermore, there is retention of a form of physiological reactivity, for when the isolated skeletal myofibrils are immersed in solutions of adenosinetriphosphate, they promptly and irreversibly change from elongated fibrils with distinct structural detail into dense spherical masses without recognizable microscopic structure.

Effect of blood and albumin on pulmonary hypertension and edema in perfused rabbit lungs

1995 ◽  
Vol 78 (2) ◽  
pp. 499-504 ◽  
Author(s):  
S. A. Kraft ◽  
S. Fujishima ◽  
G. P. McGuire ◽  
J. S. Thompson ◽  
T. A. Raffin ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Pulmonary Edema ◽  
Nitrogen Mustard ◽  
Blood Perfusion ◽  
Leukocyte Activation ◽  
Buffer Solution ◽  
Edema Formation ◽  
Pulmonary Hemodynamics ◽  
Buffer Solutions ◽  
Macromolecular Permeability

Perfusate composition may alter pulmonary hemodynamics and edema formation in perfused lungs. Perfusion for 3 h with Krebs-Henseleit solution with 3% bovine serum albumin did not produce pulmonary hypertension, pulmonary edema (assessed by lung wet-to-dry wt ratio), or increased macromolecular permeability (assessed by 125I-albumin uptake). Addition of blood to hematocrit levels of 10 or 20% resulted in pulmonary hypertension during the final hour of perfusion but not pulmonary edema or increased macromolecular permeability. Pulmonary hypertension during blood perfusion was primarily due to increased precapillary resistance. Perfusion with buffer solution without albumin produced edema and increased macromolecular permeability but not pulmonary hypertension. In lungs perfused with blood (20% hematocrit), thromboxane B2 levels increased in parallel with the pulmonary hypertension, and inhibition of cyclooxygenase or thromboxane synthase with indomethacin or dazmegrel prevented pulmonary hypertension. Perfusion with leukopenic blood (from prior nitrogen mustard administration or from filtration) also prevented pulmonary hypertension. We conclude that blood perfusion produces pulmonary hypertension via thromboxane A2 generation, which depends on leukocyte activation, and that perfusion with buffer solutions without albumin produces edema and increased permeability without pulmonary hypertension.

Biodegradable Polymers as Matrices for Control Drug Delivery

2014 ◽  
Vol 911 ◽  
pp. 336-341 ◽  
Author(s):  
Maria Mucha ◽  
Iwona Socha-Michalak ◽  
Jacek Balcerzak
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Drug Transport ◽  
Buffer Solution ◽  
First Order ◽  
Control Drug ◽  
Buffer Solutions ◽  
Control Drug Release ◽  
Control Drug Delivery ◽  
Active Substances

In the paper the results of control drug release from different forms of carriers are presented. Dibutyrylchitin, chitosan, polylactid acid and polycaprolactone have been used as matrices for delivery of therapeutic substances (ibuprofen and salicylic acid). Two configurations of matrices for drug delivery have been found. Flat drug delivery systems (films) and spherical matrices (beads) were tested in the aim of control drug transport. To control the drug release, matrices have been modified. The release of active substances from films has been tested in buffer solution of pH 5.5. Spherical matrices have been tested in buffer solutions of pH 1.4 and pH 7.2. To experimental data First order and two stage models were fitted.

Spectrofluorimetric determination of uric acid based on its activation of catalytic oxidation of pyronine Y

2008 ◽  
Vol 62 (3) ◽  
Author(s):  
Suling Feng ◽  
Xueping Liu
Keyword(s):  
Uric Acid ◽  
Buffer Solution ◽  
Activation Effect ◽  
Buffer Solutions ◽  
Spectrofluorimetric Method ◽  
Spectrofluorimetric Determination ◽  
Uric Acid Determination ◽  
Catalyzed Oxidation ◽  
Acid Determination

AbstractA novel kinetic spectrofluorimetric method for the determination of uric acid based on the activation effect of uric acid on the Cu(II) ion catalyzed oxidation of pyronine Y by hydrogen peroxide was developed. The influence of different buffer solutions was tested and the Britton-Robinson buffer solution with pH 2.2 was found to be the optimum. The detection limit and the linear range for uric acid are 0.09 μg mL−1 and 0.3–3.0 μg mL−1, respectively. The RSD for eleven determinations of 1.6 μg mL−1 uric acid was 1.6 %. Satisfactory results were obtained when using this method of uric acid determination in human urine.

A selective fluorescent probe for the detection of Cd2+ in different buffer solutions and water

2016 ◽  
Vol 45 (30) ◽  
pp. 12087-12093 ◽  
Author(s):  
Zheng Xu ◽  
Guoqiang Li ◽  
Yuan-Yuan Ren ◽  
Hua Huang ◽  
Xiaoping Wen ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Buffer Solution ◽  
Hepes Buffer ◽  
Buffer Solutions ◽  
Hepes Buffer Solution ◽  
Excellent Selectivity

A fluorescent probe NHQ, which exhibited excellent selectivity toward Cd2+ in different buffer solutions such as Tris-HCl buffer solution, HEPES buffer solution, and PBS buffer solution, and even in water, was developed.

The Demineralization of Human Dental Roots in the Presence of Fluoride

1987 ◽  
Vol 66 (8) ◽  
pp. 1370-1374 ◽  
Author(s):  
P.M.M. Hoppenbrouwers ◽  
F.C.M. Driessens ◽  
J.M.P.M. Borggreven
Keyword(s):  
Surface Layer ◽  
Outer Surface ◽  
Fluoride Concentration ◽  
Root Surface ◽  
Buffer Solution ◽  
Buffer Solutions ◽  
Ionic Product ◽  
Oral Environment ◽  
Root Surface Caries ◽  
Intact Roots

Intact roots of human molars, which had not been exposed to the oral environment, were exposed to buffer solutions of pH 5.5, which contained, besides calcium and phosphate, various concentrations offluoride. Densitometric measurements on contact-microradiograms of transverse sections of these roots produced data which were used to calculate the rate of demineralization ( Vdem). Vdem appeared to be reduced with increasing fluoride concentration and with decreasing pIOHA (i.e., the negative logarithm of the ionic product of hydroxyapatite) of the buffer solution. In addition, it was observed that, after some days of exposure, remineralization started to occur within the surface layer at some μm from the outer surface and that the region within which remineralization took place was extended inward with increasing time of exposure. These data suggest that fluoride is effective in the prevention of root surface caries. The mechanism of the interaction of fluoride with the root mineral is discussed.

Effect of Sulfide Ions on the Corrosion Behaviour of Mild Steel in Acetate Buffer

1993 ◽  
Vol 58 (3) ◽  
pp. 547-554 ◽  
Author(s):  
Hyman H. Rehan ◽  
Said A. Salih ◽  
Hassan El-Daley ◽  
Ahmed G. Gad-Allah
Keyword(s):  
Mild Steel ◽  
Corrosion Behaviour ◽  
Acetate Buffer ◽  
Acetate Buffer Solution ◽  
Buffer Solution ◽  
Solution Ph ◽  
Dissolution Rates ◽  
Buffer Solutions ◽  
Sulfide Ions

The corrosion behaviour of mild steel was investigated in acidic acetate buffer solution using impendance and potential measurements. It was found that there are two dissolution rates resulting from the duplex nature of the formed oxides. The dissolution rates were found to depend on the dissolving acetate buffer solution pH and the dissolution temperature. In all cases, the film thickness was found to decrease with time of corrosion according to the relation Cm-1 = (Cm0)-1 - kdt1/2. It was found that addition of sulfide ions increases the dissolution rate and increases the rate of hydrogen evolution reaction but does not affect the mechanism of cathodic process. The role of sulfide ions on the corrosion behaviour of steel in acetate buffer solutions is revealed by the complex plane impendance analysis.

scholarly journals The Influence of Phosphate Buffer on the Formation of N-Nitrosodimethylamine from Dimethylamine Nitrosation

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Long Xu ◽  
Zhi Sun ◽  
Qing Ming Liu ◽  
Yong Dong Liu ◽  
Ru Gang Zhong ◽  
...  
Keyword(s):  
Significant Role ◽  
Phosphate Buffer ◽  
Inhibitory Effect ◽  
Buffer Solution ◽  
Citrate Buffer ◽  
Buffer Solutions ◽  
Water Plants ◽  
Almost All ◽  
Nitrosation Reaction

Buffer solutions were widely used for almost all the investigations concerning N-nitrosodimethylamine (NDMA), a member of powerful mutagenic and carcinogenic compounds which are ubiquitous in the environment. However, whether or how the buffer matrixes influence NDMA formation is still unknown. The effect of buffer solutions on NDMA formation from the nitrosation of dimethylamine (DMA) by nitrite (NaNO2) was investigated at pH 6.4 in four kinds of buffer solutions, that is, Na2HPO4/C6H8O7, Na3(C6H5O7)/C6H8O7, NaH2PO4/NaOH, and NaH2PO4/Na2HPO4. Our observations demonstrate an unexpected inhibitory effect of the buffer solutions on NDMA formation and the phosphate buffer plays a more significant role in inhibiting NDMA formation compared to the citrate buffer. Moreover, the amount of the phosphate in the buffer was also found to greatly impact the formation of NDMA. A further investigation indicates that it is the interaction between NaH2PO4and reactant NaNO2rather than DMA that leads to the inhibitory effect of phosphate buffer during the DMA nitrosation reaction. This study expands the understanding of the influence of buffer solution on nitrosamines formation through the nitrosation pathway and further gives a hint for water plants to reduce the formation of nitrosamines.

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