Mg Of Nitrogen Research Articles

EVALUATION OF HOUSE DUST ANTIGEN IN CHRONIC TONSILLITIS

To disclose the association of house dust antigen with chronic tonsillitis, studies were made on the procedure of preparing house dust extract and on its properties as an antigen. The association was confirmed by clinical, investigation of intradermal reaction conducted in cases of chronic tonsillitis along with diseases of the nose and sinuses.Extract prepared from home dust in Japanese houses contains undoubtedly an antigenic substance and intradermal reaction following to injection of the extract results from antigen-antibody reaction. Since the skin reaction may be caused also by non-specific irritant contained in the extract, the reaction due to the antigenic substance is hardly differentiated by making use of Solution No. 1 and No. 2 (containing 0.1mg and 0.02mg of nitrogen, respectively). Tne sensitization with house dust should be determined by making use of Solution No. 3 which contains only 0.01mg of nitrogen.Nitrogen content in the house dust extract may be regarded as an index of antigen titer.The extract is preserved well with little decrease in potency for a considerable period of time at room temperature, so long as it was sealed in ampule, following to the extraction from Coca's alkaline solution and neutralization with phenolphthalein as an indicator.In cases of chronic tonsillitis complicated with focal infection, the rate of positive reactors to the extract averaged 59.0 per cent, while those without complications gave a positive rate of 42.5 per cent. The difference was proved evident. As to the complications of focal infection, the skin reaction was positive in 63.6 per cent of chronic cases of tonsillitis with rheumatism and in 58.8per cent of those with nephritis. The same result was obtained by employing extract of higher dilution.As to diseases of the nose and sinuses, the rates of positive intradermal reaction in allergic rhinitis, chronic sinusitis and chronic rhinitis were 55.0 per cent, 37.3 per cent, respectively.Positive rate of skin reaction before and after tonsillectomy differed little from each other.Mechanism of focal infection has never beestudied from the standpoint of antigenic substance introduced from the outside. Although home dust antigen which was inhaled through the respiratory passages was found not to be primary causes of focal infection, the present paper suggests some relation at least to manifestation of focal infection, and elucidation of the particular relationship depends much upon further studies.

NUTRITION OF THE PALE WESTERN CUTWORM, AGROTIS ORTHOGONIA MORR. (LEPIDOPTERA: NOCTUIDAE): II. DRY MATTER AND NITROGEN ECONOMY OF LARVAE FED ON SPROUTS OF A HARD RED SPRING AND A DURUM WHEAT

Dry matter and nitrogen balances, determined for individual instars of the pale western cutworm fed ad libitum on wheat sprouts, showed that reliable data were obtained for only the fourth, fifth, and sixth instars. During the larval period a single cutworm consumed about 10 g of fresh wheat sprouts containing about 25 mg of nitrogen. Of the consumed food, 40–50% of the dry matter and 60–70% of the nitrogen were excreted. Five days after the fifth molt the fresh weights of larvae fed on sprouts of durum wheat were significantly less than those fed on sprouts of the hard red spring wheat, but the dry weights were the same. The quantities of nitrogen found in excreta and body tissue approximated that consumed by the larvae. In contrast, however, much of the consumed dry matter (14–33%) could not be accounted for; recovery varied with variety. The percentage of the dry matter utilized, about 50%, remained constant during the last three instars. Nitrogen utilization by fourth-, fifth-, and sixth-instar larvae ranged between 25 and 45%. However, a consistently lower percentage of the nitrogen was utilized from Thatcher than from Golden Ball sprouts. On both varieties the lowest values were obtained in the sixth instar. In the excreta the percentages of insoluble dry matter, insoluble nitrogen, and volatile bases showed no consistent change during the last four instars. Seventy to eighty per cent of the excreted nitrogen was soluble in 80% ethanol, and about one-fifth of this was in the form of volatile bases. The variety of wheat sprouts fed had little, if any, effect on the composition of the excreta.

Depression on Normal Serum Bactericidal Activity by Nitrogen Mustard

Summary Single intravenous injections of 2.5, 3.0 or 3.5 mg of nitrogen mustard/kg caused a depression in the bactericidal activity of rabbit serum against Bacillus subtilis. The loss of serum bactericidal activity did not take place until about the third post-treatment day and returned to normal between the 14th and 20th days after nitrogen mustard administration. An intravenous injection of L-cysteine immediately prior to the administration of nitrogen mustard decreased the length of time that serum bactericidal activity was depressed following nitrogen mustard treatment. Nitrogen mustard treatment caused no statistically significant difference in either the natural agglutinins against Bacillus subtilis or circulating complement. Both circulating leukocytes and serum properdin were depressed by doses of nitrogen mustard that suppressed serum bactericidal activity. The serologic alterations, leukocytic changes, and the depression of serum bactericidal activity which follows near-lethal doses of nitrogen mustard were almost identical to those that follow exposure to near-lethal doses of total body x-irradiation.

Passive anaphylaxis in the dog; a quantitative study.

Summary(1) Dogs have been passively sensitized by administration of antiserum to bovine serum albumin developed in the rabbit. 21 mg of antibody nitrogen sensitized each of 2 5 dogs. All manifested symptoms of anaphylaxis and 13 of these died; 6 (of 8) following a dose of 17.3 mg of antigen nitrogen, 1 (of 4) after 10.88 mg, 6 (of 12) after 5.4 mg, and 1 following a dose of 4.33 mg of bovine serum albumin nitrogen. (2) Latent periods varied from 3% to 36 hours. No correlation could be shown between latent period and shocking dose. (3) Sensitizing doses of 10.5-16.8 mg antibody nitrogen followed by antigen in amounts of 4.33-13.0 mg of nitrogen produced symptoms of anaphylaxis in 7 dogs but all recovered, (4) An immediate and rapid fall in blood pressure was the one symptom exhibited by all 32 animals.

Some Properties of Herpes Simplex Virus

Summary A procedure has been described for the preparation of suspensions of herpes virus which are relatively pure and sufficiently stable to be quite suitable for certain types of experimentation. A 100-fold concentration of the original virus has been achieved along with a 30-fold purification. A high percentage of recovery was obtained and some preparations contained 109 ID50 per mg of nitrogen. In ionic media the maintenance of activity was favored by alkaline conditions. However, the virus was far more stable in water or 0.25 M sucrose than in ionic media. Suspensions in water were examined with the analytical centrifuge and the electron microscope. A sedimentation constant of 1175 S was obtained from which the particle size was estimated to be 96 mμ. In electron micrographs prepared from these suspensions a predominating particle was found which was round in shape and about 116 mμ in diameter. In unshadowed preparations the particles appeared inhomogeneous with regard to electron adsorption indicating the virus is composed of a central structure surrounded by an area of lower density.

Erratum: The Use of an Ion Exchange Resin for the Hydrolysis of Casein and Coffee Proteins

In the article entitled "The Use of an Ion Exchange Resin for the Hydrolysis of Casein and Coffee Proteins" (SCIENCE, 115, 95 [1952]), we have inadvertently omitted glycine 4.53 and 4.38 mg of nitrogen for the HCl and resin hydrolysates, respectively, in Table 1.

The Use of an Ion Exchange Resin for the Hydrolysis of Casein and Coffee Proteins

In the article entitled The Use of an Ion Exchange Resin for the Hydrolysis of Casein and Coffee Proteins (SCIENCE, 115 , 95 [1952]), we have inadvertently omitted glycine 4.53 and 4.38 mg of nitrogen for the HCl and resin hydrolysates, respectively, in Table 1.—G. E. UNDERWOOD and F. E. DEATHERAGE.

The N Balance Index of Low-Valine Amino Acid Mixtures and of Whole Egg Protein in the Adult Rat

Nitrogen balance was determined on adult rats receiving amino acid mixtures or whole egg protein as a source of nitrogen. Each experiment included a 7-day period on a N-free diet and a 7-day period on an amino acid mixture or an egg protein diet that supplied about half the maintenance requirement of nitrogen; this was followed by another 7-day period on a similar diet but with the nitrogen intake doubled. These diets were fed by stomach tube twice daily so that each rat received the same quantity of diet every day. The nitrogen balance index of ingested nitrogen, K´, for the complete amino acid mixtures is 0.99; for egg protein K´ = 1.18. When valine is reduced to one-sixth, or less, of the amount present in the complete amino acid mixture, K´ = 0.51 or less. Such a diminution of valine, therefore, reduces significantly the utilization of the nitrogen of the whole mixture. A relationship is described between valine nitrogen intake and nitrogen balance. It is estimated that the adult rat, under these conditions, requires 2.1 mg of nitrogen from l-valine and 4.2 mg from dl-valine per day per kilogram3/4. Using the same relationship, it is estimated that the fraction of a gram of nitrogen that must be supplied as valine, in order to cause the rentention of 1 gm of nitrogen by the rat, is 0.017 for l-valine and 0.038 for dl-valine.

Studies in Dysentery Vaccination

Summary A total of 60 children 15 to 18 years of age were injected subcutaneously with polyvalent Shigella vaccines in order to obtain information regarding toxic reactions, stimulation of serum protective power and agglutinative titers. The polyvalent vaccines used were: bivalent, Sh. flexneri II and III; trivalent, Sh. flexneri II, III and VII; pentavalent, Sh. flexneri I, II, III, VI and Sh. sonnei; and hexavalent, Sh. flexneri I, II, III, VI, Sh. sonnei and Sh. ambigua. Two vaccines standardized to contain 10 billion bacteria per ml and one vaccine standardized to contain 10 mg of bacterial nitrogen per 100 ml produced local and systemic reactions which were too severe to justify their use. They did stimulate significant increases in protective power of sera which persisted 10 to 52 weeks. They also stimulated increased agglutinative titers which were maximal one week after completion of vaccination and which varied over a wide range. Vaccines standardized to contain 8.1 mg and 8.7 mg of bacterial nitrogen per 100 ml produced local and systemic reactions which were not too severe to justify their use. They did stimulate significant increases in protective power of sera which persisted 18 to 52 weeks. The vaccine containing 8.7 mg of nitrogen per 100 ml stimulated increased agglutinative titers which were maximal one week after completion of vaccination and which varied widely. Tests of sera for increases in protective power were, in general, more sensitive for detecting humoral antibodies than were tests for agglutinative titers. Comparison in two groups of children of weekly and biweekly injections of pentavalent Shigella vaccine on the production of local and systemic reactions and antibody responses did not indicate any superiority of one interval of vaccination over the other.

The semimicro distillation of ammonia into 4% boric acid solution : Accuracy and precision of the method

1. A number of determinations of ammonia were made by the hemnnicro distillation of aminonia into boric acid. The average deviation, standaid deviation and average enois are reported. 2. An all glass apparatus offers no advantage in accuracy over the conventional apparatus. 3. For semimicro titrations involving 7–21 mg of nitrogen, 0.02 N hydrochloric acid is to be preferred over 0.05 N acid although the end-point colour matching is more difficult. 4. A fifteen fold excess of caustic is sufficient for rapid and complete distillation of ammonia. 5. Steam distillation prevents bumping in the presence of filter paper and is more rapid than distillation by direct heating.

The Determination of the Minimum Nitrogen Requirement of the Adult Dog for Maintenance of Nitrogen Balance

Since the biological value of any protein or mixture of amino acids will be dependent, at least in part, on the amino acid that is present in the lowest proportion to its quantitative requirement, it is possible to determine the relative values of nitrogen sources by determining the minimum quantity necessary for maintenance of nitrogen balance. It has been shown that only 90 mg of nitrogen per kilogram of body weight is required in the form of lactalbumin, and 140 mg of nitrogen per kilogram of body weight as casein, a partial acid hydrolysate of casein fortified with tryptophane, a complete acid hydrolysate of casein fortified with tryptophane, or an enzymatic hydrolysate of casein. However, when fortified with adequate amounts of methionine, either casein itself or the hydrolysates will maintain nitrogen balance with only 90 mg of nitrogen per kilogram of body weight.

The Immunochemistry of Toxins and Toxoids

Summary Methods are given for the accurate and reproducible assay of the biological properties of tetanal toxin and tetanal toxoid. The solubilities of toxin and toxoid, and the optimal points for their precipitation in methanol-water mixtures under controlled conditions of pH, ionic strength and temperature have been determined. Tetanal toxin is quantitatively precipitated at a pH 5.1 ± 0.1 in 40 per cent methanol at ionic strength of 0.09 and at a temperature of −5 C. MLD and Lf concentrations of over 300 times greater than the original crude toxin on a nitrogen basis and of over 5000 times on a volume basis have been obtained. A purified toxin prepared from a special toxin (Mueller) contained 16,000,000 MLD and 2400 Lf units per mg of nitrogen, and further purification of this material has resulted in a crystalline product containing 75,000,000 MLD per mg of nitrogen. Tetanal toxoid is quantitatively precipitated at a pH between 4.8 and 4.9 in 40 per cent methanol at ionic strength 0.09 and at a temperature of −5 C. Lf concentrations of 400 times on a nitrogen basis over the crude toxoid have been obtained. On a volume basis concentrations of over 5,000-fold over the original crude toxoid are possible. The purified toxoid is relatively free of sensitizing material as indicated by anaphylactic studies. I am indebted to Miss Ruth G. Wittler and Mr. Donald B. Grossberg for their help in carrying out assay and analytical procedures. Wyeth Incorporated generously supported this work.

Effect of Glucose Injections on Fasting Ketonemia After Low Protein Diets

The rapid onset of a marked fasting ketosis following low protein diets has been attributed by MacKay et al.1, 2 to a lack of “stored” protein available for the formation of antiketogenic material during fasting. Their conclusions were based on the higher nitrogen excretion observed during fasting after the high protein intakes. The difference in nitrogen excretion between groups on 5 and 25% protein diets averaged approximately 6 mg per square decimeter of body surface per day during the first 48 hours. In a comparable experiment we observed a difference in excretion of 8 mg of nitrogen. It seemed unlikely that 30 mg of glucose per square decimeter of body surface, the amount available from the metabolism of protein containing 8 mg of nitrogen, would have an appreciable effect on the metabolism of the rat. However, Deuel3 has reported a marked lowering of ketonuria after giving 100 mg of glucose per square decimeter of body surface daily.The present study was designed to determine the effect of glucose a...

The Chemistry of Pollen-Extracts

Abstract Cooke and Stull (1, 2) employed phosphotungstic acid in hydrochloric acid for the standardization of pollen-extracts, and established a protein-nitrogen unit which was taken as equal to 0.00001 mg of nitrogen per ml of extract. This method has become one of those most widely used for the standardization of extracts used in allergic practice and research. If the actual active substance in pollen-extract were known, then methods for its exact measurement might be evolved. Since, however, its nature is not specifically known, allergists are forced to accept various procedures which, at best, give only an approximation of the relative strength of successive extracts. The experiments described below point to the fact that the method of Cooke and Stull, considered the least inexact of the various procedures, is not scientifically acceptable. The total of so-called protein-nitrogen units said to be measured by this method in any one extract varies with a number of physical and chemical factors not usually controlled.

餌料蛋白の量と魚體蛋白の増生量との關係

When food protein is absorbed by a growing animal, a part of it is used in maintenance metabolism and the part utilized for increase of body protein is only a fraction of the rest. This fraction decreases with the increasing amount of absorbed. protein, since even in a grow-ing animal excretion of nitrogen rises parallel with increase in absorption of nitrogen Then the accumulation of body protein, P, may be expressed as follows : P=e-a-bx(x-xo) (1), where x is the amount of the absorbed protein, x0 that of maintenance protein ; u and b are constants. The formula holds good only when the protein is normally metabolized. Hence x should be greater than x0 and the nutritive ratio of the diet should not be too small. Re-writing the equation (1), we obtain more easily provable from, ln P/x-x0 =-a-bx (2). With gold-fish kept on diets with equal caloric value but of different nutritive ratio, the formula was proved in the following manner. The amounts of absorbed and excreted nitrogen were estimated and the nitrogen retention P was calculated, maintenance protein being as-sumed to be 9 mg/100g, 24 hrs. from the nitrogen excretion of the fish fed on high caloric but protein free diet. (Table 1). The value of In P/x-x0 was plotted against x and proved to settle on a straight line (Fig. 1). The optimum quantity of absorbed nitrogen can be obtained from equation (3). xmax= bx0+1 b (3). Nitrogen accumulation of gold-fish under the conditions of our experiment is found to be P=e-0.54-0.0108 (x-9) where x is expressed in terms of mg of nitrogen per 100 g of body weight and 24 hours. The optimum quantity of absorbed nitrogen is 103 mg, which corresponds to a diet of protein con-tent ca. 64% and of nutritive ratio 0.75.

The action of sodium nitrate upon the infection of Lucerne root-hairs by nodule bacteria

The fact that nitrates and ammonium salts harmfully affect nodule formation and the subsequent nitrogen fixation in legumes is well known, and the problem has formed the subject of an extensive literature, refer­ences to which are quoted by Giöbel (1926), by Fred, Baldwin, and McCoy (1932), and by Allison and Ludwig (1934) and need not be given here inextenso . The technical difficulties involved in analysing the action of nitrate upon the association of host and nodule organism are considerable; moreover, the great variation in cultural methods used has made it difficult to compare the results of different workers and has sometimes produced apparent discordance between them. The following facts appear, how­ever, to have been established: 1. Nitrates in sufficient concentration reduce the number of nodules formed and may even entirely inhibit their appearance. Doses of from 5 to 175 mg of nitrate nitrogen per litre have been found entirely to stop nodule formation in agar cultures of legumes (Hiltner, 1900; Flamand,1903-4; Marchal, 1901; Hills, 1918). In sand and soil cultures the inhibiting doses have been found to range from 21 to 488 mg of nitrogen per litre of soil moisture or of solution in the sand (Fred and Graul, 1916; J. K. Wilson, 1917; Hills,1918; Strowd,1920; Ohkawara, 1928). The highest of these figures in both agar and pot cultures are probably excessive, since they refer to initial doses, whereas nodule formation may sometimes have occurred when a weaker concentration, initially inhibitive, was further reduced by assimilation.