Cent Salt Research Articles

Effect of Salting Cued for Blue Cheese

Summary In the making of blue cheese, addition of 2 per cent salt to the curd just before hooping sometimes resulted in better mold growth in the cheese, rather regularly gave a lighter color and tended to control certain flavor defects.

Further Observations on Acquired Immunity to the Tick Dermacentor variabilis Say

It has been shown (Trager, 1939) that guinea pigs and rabbits once infested with larvae of the tick Derlziacentor variabilis acquire an effective immunity against these larvae. This immunity can be produced artificially by the inoculation of an extract of larval ticks and can be passively transferred. It depends to a large extent on the presence of a circulating antibody which accelerates a local cellular reaction which in turn walls off the tick larva from its normal food supply. Some additional information has now been obtained concerning two of the points left open in the previous paper. I. Immunization with various tick extracts. Guinea pigs were inoculated intracutaneously on the left side with various tick tissue extracts, or with 0.85 per cent salt solution alone. By means of the pill box method previously described, larval ticks from a single batch of eggs were then applied to both sides and to the left ear of all the guinea pigs. Table 1 shows the results of such an experiment. It is clear that antigenic substance is present in the digestive tract and the cephalic glands of partly engorged ticks, as well as in the salivary glands of both fed and unfed ticks and in whole larval ticks. The cephalic gland extract, however, is not nearly as potent as the salivary gland extracts. It is worthy of note that during the course of the inoculations guinea pigs 4 and 6 showed marked reddening and hardening of the skin at the site of injection; guinea pigs 5, 9 and 10 showed a similar but milder reaction; while the other animals showed no local reaction whatever. Nevertheless, guinea pig 2 showed more immunity than guinea pig 4. II. The coimnplenment fixation reaction. In the previous paper it was noted that guinea pig serum could not be used to demonstrate specific complement fixation because normal guinea pig serum reacted with tick extract antigen to fix complement. This difficulty has been overcome by using rabbit serum. Table 2 shows a typical result. The complement fixation technic recommended by Taliaferro (1929) was followed. The reagents used were: Antigen: Approximately 0.2 gm of larval ticks ground up in 2 cc of 0.85 per cent saline solution. Mixture centrifuged and supernatant diluted with saline to 25 cc.

Dichlorofluorescein and Potassium Chromate as Indicators in the Argentometric Estimation of Salt in Butter

Potassium chromate has long been used as the indicator in the argentometric estimation of the sodium chloride content of solutions prepared in the analysis of butter according to the method of Kohman (4) as recommended by the Subcommittee on Butter Analysis of the American Dairy Science Association (1). Recently, Bryant (2) has suggested the substitution of the adsorption indicator, dichlorofluorescein, for potassium chromate as the titration indicator. Whereas potassium chromate solutions undergo a color change from yellow to orange-red and thence brick-red, upon the addition of silver nitrate, salt solutions containing dichlorofluorescein undergo color transition from greenish-yellow fluorescent through whitish opalescent to pink. Under certain conditions the transition of the yellow to orange-red color in the chromate-silver nitrate reaction has not been considered sufficiently critical to permit sharp distinction of the colors. This lack of distinction may easily lead to utilization of an improper end point in the reaction, with accompanying error in the analysis, t tunziker specifically cautions, for example, against excess titration (3). Bryant has observed that the color change from white or whitish appearance to pink state is sudden, and, further, that the results obtained with the fluorescein dye are less (approximately 0.1 per cent salt equivalent) than when potassium chromate is used. The regults obtained using the two indicators, dichlorofluorescein and potassium chromate, when determining the salt content of solutions prepared in the routine analysis of butter received at the Department of Dairy Industry, and in experimental comparisons, are presented to indicate the differences which occur by use of the two methods.

Growth Patterns of Plants Developed from Immature Embryos in Artificial Culture

1. Methods and results are given in culturing embryos of twelve varieties of sweet cherry (Prunus avium), five of sour cherry (P. cerasus), three of European plum (P. domestica), two of American plum (P. americana), thirty-two of peach (P. persica), one of apricot (P. armeniaca), five of apple (Malus domestica), and four of pear (P. communis and P. communis x P. serotina), during five growing seasons, 1932 to 1936 inclusive. More than 20,000 individual cultures have been made. Material has been cultured from Georgia and from three locations in New York State. 2. Embryos in culture do not pass through the embryonic stages characteristic of embryos on the mother plant. Instead they enter at once into an independent development characteristic of the age of the embryo when excised. 3. The growth pattern for peach embryos treated with a disinfectant and grown on 0.6 per cent agar media with 0.5 per cent glucose and salt mixture T may be summarized as follows: (A) no development earlier than 51 days of age afte...

Studies on Salt Fish: II. The Effect of Salt Concentration on Preservation

The preserving action of salt, as determined chemically and bacteriologically, increases with increasing salt concentration (8 to 32%) and decreasing temperature (21 to 10 °C). It shows in a lengthening of the period of lag before rapid increase in volatile bases. The increase begins when the bacterial count reaches 10–20 million per ml. on 10 per cent salt agar, and its rate is not influenced by salt concentration. The hypothesis is advanced that the trimethylamine oxide present in the fish is reduced very rapidly to trimethylamine when the reduction potential reaches a definite point.

Studies on the Antigenic Substances of Clostridium Parabotulinum. II

Abstract In studies on the complement fixation and precipitin reactions (1, 2, 3), it has been shown that extracts prepared by alternate freezing and thawing of suspensions of Clostridium parabotulinum are highly group specific when tested with antiserums produced by the inoculation of intact organisms. It was thought that it would be of interest to test the antigenic properties of such extracts when injected into the animal body. Extracts were prepared from seven representative strains of Cl. parabotulinum by various methods. Twenty-four hour cultures in glucose veal broth were centrifugalized and washed three times in salt solution. In one series the organisms were suspended in neutral distilled water, in a second in neutral 0.85 per cent salt solution, and in a third in alkaline salt solution (pH 8.0). The suspensions were frozen in a mixture of crushed ice and salt and thawed rapidly by plunging into warm water (70°C.).

THE EFFECT OF SODIUM CHLORIDE ON THE CHEMICAL CHANGES IN THE BLOOD OF THE DOG AFTER OBSTRUCTION OF THE CARDIAC END OF THE STOMACH

A study is reported of the effect of different methods of treatment on the toxemia of cardiac obstruction. The average duration of life of untreated dogs is 3 days. Three dogs treated with 1 per cent salt solution subcutaneously lived 32, 36, and 45 days respectively without developing a toxemia. 2 per cent glucose similarly given, does not alter the course of the toxemia. Concentrated salt solution in small quantities given directly into the jejunum prevents the marked rise in non-protein nitrogen but does not materially prolong life. Release of the obstruction does not change the course of the toxemia in untreated animals. The subcutaneous injection of 1 per cent sodium chloride solution after release of the obstruction causes a rapid return of the blood to normal and allows the animal to recover. A similar amount of fluid given as 2 per cent glucose does not alter the course of the toxemia after release of the obstruction.

Studies on Butter Salts

Summary 1. Ten leading butter salts, representing three flake salts and seven cube salts, were studied with reference to their physical, chemical, and bacterial properties as related to their effect on flavor, body, texture, and color of butter. 2. Some of the salts were badly caked in the barrel while others were free-flowing. The most freely flowing salts were those that showed the greatest freedom from chemical impurities and that were lowest in moisture content. Numerous tests showed that the drier the salt the less its tendency to lump. As the moisture content of the salt increases the salts lose their free-flowing property and cake profusely. For similar reasons the presence in salt of calcium chloride and magnesium chloride, which are highly deliquescent, diminishes the free-flowing property of the salt and causes it to lump. 3. The flake salts were found to be considerably more bulky than the cube salts. Taking the weight of a given volume of water as one, the weight of the flake salts averaged 0.86 and of the cube salts 1.26. With the weight of the commercial package of salt standardized to 280 pounds per barrel, the barrel for cube salt need be only two-thirds as large as the barrel for flake salt. 4. Several of the salts contained foreign matter in sufficient amounts to produce a very turbid brine and dirty color when dissolved in water. Such salts are objectionable, particularly when intended for use in the preparation of brine for the treatment of parchment liners, circles, and wrappers. 5. The salts in the original containers were found to be bacteriologically clean. The bacterial counts ranged from less than one colony per gram of salt to seven colonies, averaging from 2 to 3 colonies for all salts. Unless contaminated in the creamery after the barrel is opened, due to improper storing or handling, these salts may be considered entirely negative as a possible source of bacterial contamination of butter. 6. The great majority of the crystals in each salt passed through 40 and 60 mesh screens. The flake salt showed a considerably coarser grain and a wider range of crystal size than the cube salt. Thus, of the flake salts about 60 per cent of the crystals passed through 40 and 60 mesh screens while 27 per cent required a coarser screen. Of the cube salts, approximately 90 per cent of the crystals passed through the 40 and 60 mesh screens while only 1.7 per cent required a coarser screen. 7. The ten salts were very similar in their rates of solution. During the first twenty seconds there was a tendency for the flake salts to show slightly greater rapidity of solution than the cube salts but at the end of twenty-five seconds the amount of salt dissolved averaged the same for both types of crystals. At the end of two minutes the solution of each salt was complete. After the first five seconds each liquid contained 19.75 per cent or more of salt in solution. This salt concentration is fully equal to the strength of the brine in butter containing 3 per cent salt. This rapidity of solution of each of the ten salts suggests that such minute differences in solubility rate as were observed between individual brands and between the two types of salt are too slight to be of any significance from the standpoint of preference for any one salt in butter manufacture. 8. The percentage of sodium chloride in the 10 salts, as determined by direct analysis, ranged from 98.34 to 99.69 per cent, averaging 99.14 per cent. The sodium chloride content as determined by difference ranged from 98.59 to 99.94 per cent. Phosphates and barium salts were entirely absent in all salts. The largest chemical impurity consisted of calcium sulphate ranging from 0.01 to 1.225 per cent. Small amounts of calcium and magnesium chlorides, magnesium and sodium sulphates, and calcium and magnesium carbonates, and traces of iron, were also present. The insoluble matter ranged from 0.003 to 0.031 per cent and the moisture from 0.005 to 0.14 per cent. 9. When working these salts into butter, both under experimental conditions and in commercial manufacture, no differences in flavor, body, texture, and color could be detected in the finished butter. Likewise, the addition to the pure salt of impurities in relatively large amounts, such as 2 per cent CaSO4, 3 per cent KCl, 1 per cent CaCl2, and 1 per cent MgCl2, failed to have any noticeable effect on the flavor of the butter. 10. These findings suggest that, while chemical purity in butter salts is highly desirable, such small amounts of chemical impurities as are found in the above standard butter salts are incapable of impairing or changing the quality of butter.

The Cultivation of a Parasitic Amoeba from the Cockroach

The object of the present paper is to record the successful and long continued cultivation of a parasitic amoeba (Endamoeba thomsoni) from the cockroach, Periplaneta americana. There seems no reason to review the previous work on the cultivation of the parasitic amoeba as this has been done very thoroughly in the recent paper of Dobell and Laidlaw (1926). It is to be noted, however, that the present work is a continuation of a series of investigations in which various parasites have been cultivated on a simple dilution of inactivated human serum in saline (Blastocystis lhominis of man, Barret, 1921; Balantidiumz coli of man, Barret and Yarbrough, 1921; Endamoeba barreti of the turtle, Barret and Smith, 1924, and Taliaferro and Holmes, 1924; Endamoeba ranarum of the frog, Barret and Smith, 1926, and Taliaferro and Fisher, 1926). Although most of the cultivation of the parasitic amoebae of mammals has been done with the medium of Boeck and Drbohlav (1925) or with modifications of it, and although Dobell and Laidlaw (1926) were unable to use our medium for the cultivation of E. histolytica and several other amoebae of mammals, it is interesting to note that Craig (1926) has succeeded in growing E. histolytica in seven parts of 0.85% saline plus one part of inactivated human blood serum. This medium is obviously very similar to that used throughout our investigations and suggests that dilutions of inactivated serum in different percentages of saline may prove a very simple and efficient method for the cultivation of a large range of parasitic protozoa. The original medium used by one of us (Barret 1921) in the cultivation of Blastocystis was a 1-10 dilution of inactivated human blood serum in 0.5 per cent salt solution. In the present work it was found best to double the dilution of serum (19 parts of 0.5 per cent NaCl solution and 1 part of inactivated human blood serum). In all of our work we have found 0.5 per cent salt solution to be superior to 0.7 or 0.85 per cent. This medium varied from pH 7 to PH 8 depending upon the length of time it was kept before use. In our experience a PH anywhere in this range is satisfactory for the present amoeba. All of the present work was done with the American cockroach, Periplaneta americana. The roaches around Charlotte, N. C., are almost

EDEMA

The rapid disappearance, in children with edema, of the cutaneous elevation produced by intradermal injection of 0.2 cc. of 0.8 per cent salt solution was described by McClure and Aldrich1in 1923. They suggested that this test might be of value for detecting disturbed water balance in the tissues, and for following the progress of such disturbance. Later these authors2reported this test to be a valuable method for determining immediate prognosis of conditions in children characterized by generalized edema, with albumin, casts and, in some cases, red blood cells in the urine, but unassociated with nitrogen retention in the blood. They also reported the test to be an aid in directing the therapeutic management of these cases. Baker3stated that in scarlet fever and diphtheria the disappearance time of intradermally injected salt solution is reduced in proportion to the severity of the intoxication and that the test aids in

THE INTRACUTANEOUS SALT SOLUTION TEST

In May, 1925, one of us 1 reported that the intracutaneous salt solution test, as devised by McClure and Aldrich 2 for the study of edema, afforded a simple method of determining the efficiency of the circulation in the extremities. The present report deals more fully with the nature of this reaction and with its clinical applications. NATURE OF TEST AND MECHANISM OF ACTION When 0.2 cc. of an 0.85 per cent salt solution is injected into the skin of a normal individual, sixty minutes or more is required for its complete absorption. In cases showing edema, the disappearance time is decreased in direct ratio to the degree of edema, and in extreme cases the injected fluid disappears so rapidly that it is impossible to produce a wheal. These observations hold true for all edema, whether it is of the so-called renal or cardiac types. Aldrich 3 discusses the mechanism

The nutritive value of the various layers of the wheat and corn kernel

Much work has been done on the relative vitamine content of the several layers in cereal grains. The peripheral layers and the germ are rich in vitamines. There is, however, not so much information available with regard to the relative content of the proteins in the various layers. The present contribution concerns itself with a chemical as well as a biological analysis of such proteins. The milling fractions of wheat and corn were analyzed to determine their content of total protein, gliadin (the portion soluble in 70 per cent alcohol), globulin (the portion soluble in 5 per cent potassium sulfate solution) and glutenin (obtained by subtracting the protein representing globulin and gliadin from the total protein). The methods followed were those outlined in Methods of Analysis of the Assoc. of Official Agricultural Chemists, 1920. At the same time, the biological value of the wheat and corn fractions was determined according to Mitchell's method, using rats as the experimental animals. Chemical analysis showed that among the samples of wheat (bran, middlings, red dog, first clear, second clear and patent flour), the gliadin content increases as we go from bran to patent flour; the globulin content is much higher in the bran, standard middlings and the red dog than it is in the three grades of flour; and the glutenin content diminishes as we proceed from the outer layers to what represents the patent flour. The animal experiments, excepting for minor details, were carried out as suggested by Mitchell (see above). The diet consisted of the milling fraction (corresponding to about 1.3 per cent nitrogen), together with 2 per cent cod liver oil, 0.5 cc. aq. sol. of rice polishing (corresponding to 1 gm. of rice polishing), 7 per cent butter, 15 per cent lard, 4 per cent salt mixture (OSborne and Mendel's), and enough starch to make a total of 100 per cent.

EXPERIMENTAL OBSTRUCTION OF THE JEJUNUM

Chemical changes are reported occurring in the blood of animals with obstruction of the jejunum, in which distilled water or sodium chloride solutions were introduced directly into the lumen of the intestine below the point of obstruction. Distilled water given daily from the beginning of the obstruction, had no influence on the development or course of the toxemia. 1 and 2 per cent salt solutions prevented a toxemia in uncomplicated cases. One animal so treated lived 30 days. Distilled water, given after the onset of toxemia, did not alter the progress or outcome of the toxemia. 10 per cent sodium chloride solution, administered after the onset of toxemia, controlled it in most cases for a long period. Hydrochloric acid had no effect on the course of the toxemia.

The experimental transmission of leishmaniasis to animals.

On December 18th, 1922, an autopsy (No. 3853) was performed on a patient who had died of kala-azar that day in the Peking Union Medical College Hospital. The spleen was found to be unusually heavily infected with Leishmania donovani, spleen smears showing hundreds of organisms in every field under the 1.9 mm. oil immersion objective. A portion of the spleen was taken, using sterile precautions, ground in Rosenow's tissue crusher, and mixed with 0.85 per cent salt solution to make an emulsion which easily passed through a fine hypodermic needle. The same suspension was used to inject the following series of animals, all of which were injected intraperitoneally except the dogs which were injected intravenously:2 dogs received 5 cc. and 4.5 cc. respectively; 2 guinea pigs, 0.5 cc.; 2 white rats, 0.5 cc.; 2 black mice, 0.3 cc.; 5 hamsters, 0.3 cc.The hamster (Cricetulus griseus M-Edw.) is a species of field mouse which we describe more fully in another paper read at this meeting.The results of these inoculati...

A Study of the Incorporation of Proteins in Creamery Butter

Sumamry The average protein content of the normal samples of butter in these experiments was 0.3727 per cent. The average protein content of the butter which was worked in the buttermilk was 0.5264 per cent. The average protein content of the unwashed butter was 0.5177 per cent. The average loss of protein due to washing the butter was 0.1450 per cent. The protein content of the unwashed butter, churned at abnormally high temperature, was 0.5407 per cent. The protein content of the butter to which starter had been added was 0.4718 per cent. Nitrogenous compounds were not incorporated in the butter to any appreciable extent by using the methods of manufacture followed in these experiments. One per cent was found to be sufficient allowance for all the constituents of butter which may be classified under the term curd. By incorporating 15.5 per cent moisture and allowing 1 per cent for curd as much as 3.5 per cent of salt may be incorporated without reducing the fat content of the butter below 80 per cent. No difference in score or selling price of the duplicate lots of butter was made upon the Chicago market. Speckled butter was not found in any of the samples. Milky brine was not found in any samples of the finished butter. With the exception of one churning the keeping quality of the washed butter was slightly better than that of the unwashed butter.

Prompt Macroscopic Agglutination in the Diagnosis of Glanders

Summary A method has been devised whereby a prompt clear cut macroscopic agglutination for the diagnosis of glanders can be obtained in two hours. Fifteen strains of B. mallei were tested and one obtained which is constant in its agglutinability with positive sera. The best culture medium is glycerin-potato-agar (2.5 acid to phenolphthalein) carefully prepared (see text). Great care must be used in the preparation of the stock suspension of B. mallei (see text). For the tests, fresh dilutions in 0.85 per cent salt solution are made from the stock suspension. No carbolic acid is added to the stock nor to the dilutions. The agglutination test is valuable in the routine examination of horses. With this test nearly all early and acute cases can be detected and thus the spread of the disease can be prevented. A negative reaction by a single agglutination test if not confirmed by the ophthalmic and the complement fixation tests does not prove the case negative; nor does a single negative result either by the complement fixation or ophthalmic tests. A positive reaction by any of the three methods is more significant than a negative one. All three tests must be performed in order to pronounce the horse negative. In my experience with the present series of cases a reaction of less than 1:1000 by agglutination (if the other two tests are negative and if there are no clinical symptoms) is not indicative of glanders in the horse. If the reaction is above a 1:1000 the horse should be kept under observation; even if he does not show active glanders, the possibility of a carrier condition should be thought of. Isolation of such horses would be a very safe measure for preventing the infection among the other horses. The bacteriological method of inoculating the guinea-pig with glanders material for the “Strauss” reaction is successful in only 25 per cent of cases (active lesions). Autopsy findings, if possible, should be confirmed by pathological sections. A great many cases are pronounced glanders on autopsy, which do not show typical lesions under the microscope. All stables should be under the supervision of the City Health Department and glanders in horses should be put in the same category as typhoid, meningitis, etc. in man, if glanders in New York City is to be eradicated. Sera that come to the Health Department for diagnosis should be accompanied by a complete history of each horse. Follow up work should be possible. Records of the three tests and autopsy findings should be accessible and some mark of identification for every horse should be devised by which all records of a horse can be compared. Only in some such way can a really scientific study of the disease be made and the right conclusions drawn.