scholarly journals OSMOTIC PRESSURE STUDY OF PROTEIN FRACTIONS IN NORMAL AND IN NEPHROTIC SUBJECTS

1939 ◽  
Vol 69 (6) ◽  
pp. 819-831 ◽  
Author(s):  
Jaques Bourdillon
Keyword(s):  
Osmotic Pressure ◽  
Normal Serum ◽  
The Other ◽  
Protein Fractions ◽  
Molecular Weights ◽  
Other Hand ◽  
Normal Albumin

In serum of patients with nephrosis both albumin and globulin showed by osmotic pressure nearly double the molecular weights of normal albumin and globulin. In the urines of such patients, on the other hand, both proteins showed molecular weights lower even than in normal serum. The colloidal osmotic pressures were measured by the author's method at such dilutions that the van't Hoff law relating pressures to molecular concentrations could be directly applied. For the albumin and globulin of normal serum the molecular weights found were 72,000 and 164,000 respectively, in agreement with the weights obtained by other methods.

Malate dehydrogenase from thermophilic Humicola lanuginosa and Mucor pusillus: purification and comparative properties of the enzymes with differing thermostabilities

1984 ◽  
Vol 62 (7) ◽  
pp. 559-565 ◽  
Author(s):  
Anupam S. Wali ◽  
Autar K. Mattoo
Keyword(s):  
Malate Dehydrogenase ◽  
Conformational Changes ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
The Other ◽  
Heat Inactivation ◽  
Ph Optimum ◽  
Molecular Weights ◽  
Other Hand ◽  
Humicola Lanuginosa

Malate dehydrogenase (L-malate:NAD+ oxidoreductase, EC 1.1.1.37) was purified from the thermophiles Humicola lanuginosa and Mucor pusillus. The H. lanuginosa enzyme was homogeneous on sodium dodecyl sulphate – polyacrylamide gels, while the M. pusillus enzyme was more than 95% pure. The two enzymes appeared to be composed of two subunits of equal size, each of 36 000 daltons (H. lanuginosa) or 33 000 daltons (M. pusillus). The native enzymes revealed molecular weights of 68 000 as determined by gel filtration. The isoelectric points of malate dehydrogenase from H. lanuginosa and M. pusillus were 3.9 and 4.2, respectively. The reduction of oxaloacetate by the H. lanuginosa enzyme was optimum at pH 8.5–9 with apparent Km's of 0.12 mM for oxaloacetate and 0.027 mM for NADH. On the other hand, M. pusillus enzyme snowed a pH optimum of 7.8–8.5 with apparent Km's of 0.075 mM for oxaloacetate and 0.1 mM for NADH. The L-malate oxidation reaction was catalyzed optimally at pH 10 by the H. lanuginosa enzyme with apparent Km's of 5.8 mM for malate and 0.1 mM for NAD, while the M. pusillus enzyme catalyzed it optimally between pH 9.5 and 10 with apparent Km's of 4.44 mM for malate and 0.16 mM for NAD. The optimum temperature for reduction of oxaloacetate was 50 °C for both the enzymes. The H. lanuginosa enzyme was resistant to heat inactivation at 40 °C, but lost 60% of its activity after 15 min at 50 °C. Mucor pusillus enzyme, on the other hand, retained 90% activity at 60 °C after 10 min. The two enzymes were protected from heat inactivation by monovalent cations (viz Na+, K+, and NH4+), as well as citrate, which may possibly involve conformational changes.

Equation for osmotic pressure of serum protein (fractions)

2004 ◽  
Vol 96 (2) ◽  
pp. 762-764 ◽  
Author(s):  
Johan Ahlqvist
Keyword(s):  
Molecular Weight ◽  
Regression Analysis ◽  
Osmotic Pressure ◽  
Serum Protein ◽  
Protein Fractions ◽  
Fibrinogen Concentration ◽  
Nonlinear Regression Analysis ◽  
Molecular Weights ◽  
Wide Range ◽  
Better Than

The colloid or protein osmotic pressure (Π) is a function of protein molarity (linear) and of Donnan and other effects. Albumin is the major osmotic protein, but also globulins influence Π. Equations based on concentrations of albumin and nonalbumin (globulin concentration + fibrinogen concentration) protein approximate Π better than albumin alone. Globulins have a wide range of molecular weights, and a 1956 diagram indicated that Π of globulin fractions decreased in the order α1-, α2-, β-, and γ-globulin. The molecular weight of the serum protein fractions had been extrapolated, so van't Hoff's law and nonlinear regression analysis of the curves permitted expression of the diagram as an equation: [Formula: see text], where Πs,Ott,2°C,cmH2O is Π of serum at 2°C (in cmH2O) computed from the 1956 diagram, Ctot is the concentration (g/l) of total protein in serum, and xalb, xα1, xα2, xβ, and xγ are the fractions of albumin, α1-, α2-, β-, and γ-globulin, respectively. At one and the same concentration of fractions, Π“Ott” decreases in the order α1-globulin, albumin, α2-globulin, β-globulin, and γ-globulin.

Cystine in Human Serum Proteins

1956 ◽  
Vol 2 (2) ◽  
pp. 65-74 ◽  
Author(s):  
Miriam Reiner ◽  
Michael X Sullivan
Keyword(s):  
Multiple Myeloma ◽  
Human Serum ◽  
Serum Protein ◽  
Serum Proteins ◽  
Normal Serum ◽  
The Other ◽  
Protein Fractions ◽  
Human Hemoglobin ◽  
Average Value ◽  
Human Serum Proteins

Abstract 1. The amount of cystine was determined in a number of serum protein fractions separated by the procedure of E. J. Cohn. In albumin, the average value was 6.40 per cent for cystine; for γ-globulin the average value was 1.94 per cent; the other fractions tested were mixtures and varied according to the different globulins present. Globin from human hemoglobin contained 1.90 per cent cystine. 2. Separated fractions from three types of multiple myeloma cases have been presented showing abnormal fractions in the α-, β-, and γregions. The percentage of cystine was determined, and except for the fraction from the "gamma" type of myelomas, which contained 6.15 per cent cystine, the anomalous protein fractions contained about the same amount found in separated fractions of normal serum.

scholarly journals On the vapour-pressure and osmotic pressure of a volatile solute

1908 ◽  
Vol 81 (548) ◽  
pp. 336-336 ◽  
Keyword(s):  
Liquid Phase ◽  
Hydrostatic Pressure ◽  
Osmotic Pressure ◽  
Vapour Pressure ◽  
Specific Volume ◽  
Vapour Phase ◽  
The Other ◽  
Other Hand ◽  
Specific Volumes

It follows by a method given in a recent paper by the author that if the osmotic membrane be assumed to be impermeable to the solute, the formula for the change of vapour-pressure of a volatile solute with hydrostatic pressure, and also the formula for the osmotic pressure which is deduced from it, must be the same as the formula for a non-volatile solute, and should not contain any terms depending on the vapour-pressure of the solute, except in so far as it may affect the hydrostatic pressure of the solution. If, on the other hand, an osmotic membrane is regarded as a vapour-sieve permeable to the vapour of the solution but not to the liquid phase, the equation takes a different form, depending on the concentration of the constituents in the vapour-phase. If c 1 , c 2 , etc., be the concentrations of the constituents in grammes per gramme of the vapour, and if U 1 , U 2 , etc., be the specific volumes of the constituents in the solution, the change of total vapour-pressure dp of the solution for a change of hydrostatic pressure d P is given by the relation, ∑ c U d P = v dp , where v is the specific volume of the whole vapour-phase. If only on constituent is volatile, this relation reduces to the form U d P = v dp for that constituent.

scholarly journals EXPERIMENTAL LIVER NECROSIS; III. NITROGENOUS METABOLISMS

1907 ◽  
Vol 9 (5) ◽  
pp. 552-568
Author(s):  
Richard M. Pearce ◽  
Holmes C. Jackson
Keyword(s):  
Total Nitrogen ◽  
Ammonia Excretion ◽  
Liver Parenchyma ◽  
Normal Serum ◽  
Considerable Extent ◽  
The Other ◽  
Liver Necrosis ◽  
Other Hand ◽  
Nitrogen Elimination ◽  
Experimental Liver

1. In focal and diffuse necroses of the liver due to hæmotoxic sera there occurs an increased elimination of total nitrogen with a corresponding augmented output of urea. The ammonia excretion becomes slightly diminished at first, but later rises somewhat above normal. The undetermined nitrogen is markedly increased. 2. In diffuse degeneration with no necrosis on the other hand only a slightly increased output of total nitrogen is evident. A rearrangement of the urea-ammonia proportion occurs in that the ammonia excretion is augmented while the urea elimination is correspondingly diminished. The undetermined nitrogen rises but little. 3. In control experiments with normal serum no effect is produced. 4. These results would appear to indicate that in lesions characterized by uniform degeneration of the liver parenchyma, in contradistinction to necrosis, there occurs no increased nitrogen elimination but merely a disturbance of the urea-forming function of the cell without the appearance in the urine of products of autolysis. On the other hand in necrosis, of even considerable extent, the total-nitrogen is greatly augmented, as is also the rest-nitrogen; while the production of urea, on account of the persistence of normally functioning liver cells, remains relatively unchanged. This "factor of safety"32 possessed by the liver is, we think, one of the most important results brought out in this investigation and must be given great weight in any consideration of the chemistry of hepatic disturbances.

scholarly journals The inhibitory action upon subsequent Phagocytosis, exerted on active normal serum by inactive normal serum through which Bacilli have been passed

1907 ◽  
Vol 79 (534) ◽  
pp. 482-484 ◽  
Keyword(s):  
Human Serum ◽  
Salt Solution ◽  
Inhibitory Action ◽  
Normal Serum ◽  
Normal Human Serum ◽  
The Other ◽  
Supernatant Fluid ◽  
Other Hand ◽  
Difference Of Opinion ◽  
Normal Human

Considerable difference of opinion still prevails regarding the nature of the opsonic substances present in normal serum. Wright, Bulloch and Atkin, etc., uphold the view that the opsonin of normal serum is a simple thermolabile body. Muir, on the other hand, regards the opsonin as a body which behaves like complement, while Dean holds that it is essentially thermostable and in all probability co-operates in its action with a thermolabile complement. The demonstration of anti-bodies by complement-deviation experiments (Bordet, Gengou, Pfeiffer and Friedberger, etc.) has recently proved fruitful in connection with the bacteriolysins, hæmolysins, precipitins of immune sera, and the following experiments were designed to test whether, by a similar method applied to phagocytosis, the presence in normal serum of opsonic amboceptors could be demonstrated :─ Experiment I. Normal human serum was heated for 30 mins. at 60° C. (denoted “ A ”). A very thick emulsion of tubercle bacilli in 1 : 1000 salt solution was added in equal volumes to “ A ” and kept in contact therewith for 1 hr. 30 mins. at 37° C. The mixture was then centrifugalised (7000 revolutions per minute) for 1 hr., and the supernatant fluid pipetted off (denoted “ B ”).

scholarly journals An Unusual Bacillus recovered from Cases presenting Symptoms of Dysentery

1929 ◽  
Vol 28 (4) ◽  
pp. 355-362 ◽  
Author(s):  
F. H. A. Clayton ◽  
S. H. Warren
Keyword(s):  
Early Phase ◽  
Normal Serum ◽  
The Other ◽  
Minute Amount ◽  
Presenting Symptoms ◽  
Other Hand ◽  
Peptone Water ◽  
Diseased Condition ◽  
Degree Of Similarity ◽  
Ferment Glucose

Organisms which appear to be morphologically, culturally, and serologically identical have been recovered in four separate outbreaks of illness suggestive of dysentery.They have been readily isolated in considerable numbers from all cases examined in the early phase of the attack.When 1 per cent, peptone water is used as a basis for carbohydrates these organisms usually leave lactose, mannite, dulcite, and saccharose unaffected but ferment glucose and maltose with the production of acid. Barely, a minute amount of gas is also produced from glucose and occasionally slight acid and gas from dulcite. On the other hand, when Lemco broth (Dudgeon and Pulvertaft, 1927) is used as a basis, glucose, dulcite, and maltose are consistently fermented with the production of acid and gas.Agglutination tests against normal sera and against anti-sera prepared from the dysentery and paradysentery bacilli and from B. paratyphosus A are uniformly negative but strains of the organism derived from all four sources are agglutinated to approximately the same titre by an anti-serum prepared from one of them although this anti-serum has no effect on three organisms whose reactions present some degree of similarity.The organisms do not appear to be toxic for rabbits.With all patients affected in these outbreaks, whose blood was available for examination, the serum has shown the presence of specific agglutinins which could not be demonstrated in normal serum.On the whole, therefore, the evidence suggests that these organisms may be responsible for the diseased condition.

scholarly journals Plant growth, metabolism and adaptation in relation to stress conditions: Further studies supporting nullification of harmful effects of salinity in lettuce plants by urea treatment

2008 ◽  
Vol 54 (No. 3) ◽  
pp. 123-131 ◽  
Author(s):  
M.N.A. Hasaneen ◽  
M.E. Younis ◽  
D.M.A. El-Bialy
Keyword(s):  
De Novo ◽  
Foliar Application ◽  
The Other ◽  
Growth Stages ◽  
Water Control ◽  
Urea Fertilizer ◽  
Molecular Weights ◽  
Novel Proteins ◽  
Other Hand ◽  
Adult Growth

Foliar application of urea to lettuce plants induced pronounced changes in the total amount and in the relative composition of the nitrogen pool. As compared with untreated lettuce plants, urease (UR), nitrate reductase (NR), asparaginase (AS) and glutamine synthetase (GS) activities were, in general, increased with an increase in the concentration of urea. On the other hand, salinization of lettuce plants with NaCl induced a significant decrease in the activities of UR, NR, AS and GS, at vegetative and adult growth stages. In general, treatment of lettuce plants with increasing concentrations of urea fertilizer in combination with each of the levels of salinity resulted in significant increases in all enzyme activities. Treatment with increasing concentrations of urea fertilizer induced significant decreases both in glycine and proline contents below control levels. On the other hand, salinization of lettuce plants with NaCl induced significant pronounced increases in the contents of the two amino acids. Further increments in glycine and proline contents were observed in differently salinized lettuce plants foliary sprayed with increasing concentrations of urea at vegetative and adult growth stages. Salinity solely enhanced the occurrence of novel proteins that were detected neither in the water control nor in the urea-treated plants. Protein banding patterns of lettuce plants treated with urea either alone or in combination with NaCl showed different <I>de novo </I>protein bands with different molecular weights, induced by urea and/or NaCl at vegetative and adult growth stages.

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

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