John J. Morton

Filter Paper Disc Modification of the Oxford Cup Penicillin Determination.

At the present time biological assay methods are the sole means of determining penicillin potency. A number of such methods are in use in various laboratories; 1 however, the Oxford cup method, 2 with several modifications, 3 has continued to be regarded as a procedure in which a commensurate accuracy and speed may be obtained with a minimum of labor. The following filter paper disc modification should reduce the labor and time involved in setting up this test, while the case with which extra replicates may be run should increase the tests accuracy. The principal modification lies in the use of a thick filter paper disc saturated with the penicillin sample, substituted for the sample-containing small cylinder used in the Oxford cup method. These discs may be conveniently set up on the seeded plates at a rate of about 6 per minute, a rate considerably more rapid than that in the original method. Another advantage of the discs is that the test plates may be manipulated freely to facilitate reading. Experience with a large number of tests has indicated that the zones of inhibition obtained with the discs are more consistent and more sensitive to variations in the penicillin content of the sample than the zones obtained with the cup method. This improvement may be due to a more consistent contact of the penicillin solution with the agar and to a more even diffusion from the disc. The test organism, Staphylococcus aureus H† (Oxford strain), tends to produce a somewhat granular growth in nutrient broth. With the use of peptone broth as the seeding medium, a more diffuse growth is obtained and this in turn effects a more even seeding of the test plates.

Determination of gastric acidity without intubation by use of cation exchange indicator compounds.

Summary The preparation of a cation exchange indicator compound called quininium resin indicator compound has been described. The rationale and method of its use have been stated. In vitro tests have demonstrated that the quininium cation present in this compound will be displaced by the hydrogen ions of dilute hydrochloric acid solutions and of the gastric juice. In vivo experiments have shown that, by administering this cation exchange resin indicator compound orally and noting the time of appearance of the quininium cation in the urine, the presence or absence of free hydrochloric acid in the gastric juice can be determined without subjecting the individual to intubation.

Spinal anesthesia in the treatment of megacolon and obstinate constipation

P RIOR to 1927, the treatment of idiopathic megacoIon was varied and extremeIy unsatisfactory. The conservative treatment consisted of diet, catharsis and repeated enemas. The resuhs were far from encouraging and after a Iong tria1, many of these cases were treated surgicaIIy. The surgica1 treatment was attended with radica1 procedures and high mortaIity. The more radica1 procedures varied from coIostomy, partia1 coIectomy to tota extirpation of the coIon. Even after such formidabIe procedures, the resu1t.s were often poor. Various theories have been advanced as to the cause of idiopathic megacoIon ranging from adhesions on the outside of the bowe1 to vaIve formation within. Briefly, some of these theories wiI1 be mentioned. An abnormaIIy Iong mesentery, chronic coIitis, increased Iength of the coIon, actua1 mechanica obstruction and congenita1 aplasia of the muscuIar tunics, were the outstanding theories unti1 rgoo. At that time Fenwick considered the possibiIity of spasm of the sphincter ani associated with fissures in the ana margin. In rgo7, Bing considered a neuropathic diIatation and hypertrophy of the coIon, probabIy a segmenta defect associated with changes in the sympathetic nerves. The true definition of idiopathic megacoIon infers a diIatation of the bowe1 without any obvious mechanica obstruction inside or outside of the bowe1. If we are to adhere to this definition, many of the theories, by the nature of their expression inferring some mechanica obstruction, cannot be considered in a discussion of idiopathic megacoIon. In 1895, Langley and Anderson showed that stimuIation of the Iumbar sympathetic gangIia caused an inhibition of peristaIsis with diIatation of the coIon and contraction of the interna sphincter of the anus. GaskeII feIt that impuIses inhibitory to the muscuIature of the Iarge bowe1 and motor to the interna sphincter of the anus pass through the Iumbar sympathetics. Learmouth and Markowitz have since substantiated this opinion by pIacing a buIb against the interna sphincter and recording contractions foIIowing stimuIation of the gangIia. In 1924, RoyIe and Hunter removed the Iumbar sympathetics for reIief of spastic paraIysis of the Iower extremities. They noted that one of the benefits of the operation was the striking reIief of the obstinate constipation that had been present in these patients. It was not unti1 1926, however, that a practica1 appIication of these observations was made when Wade and RoyIe performed a Iumbar sympathectomy for Hirschsprung’s disease (idiopathic megacoIon). The child made a fine recovery with exceIIent cIinica1 improvement and reIief of the constipation. In 1928, Judd and Adson reported 2 cases and in 1930, Scott and Morton reported one case. Since then numerous cases have been reported with varying degrees of success. The next step in the treatment of the disease was the introduction of spina anesthesia as a preoperative test to determine whether sympathectomy wouId be of benefit. This test was used prior to sympathectomy in the case reported by Scott and Morton. The resuIts were striking.

Effect of Petroleum Ether Extract of Mouse Carcasses as Solvent in Production of Sarcoma.

The production of sarcomata in mice may be influenced by the solvent used for the carcinogenic hydrocarbon. 1 Most experiments have been carried out with vegetable oils, lard, cholesterol or paraffin which are effective vehicles for 1:2:5:6-dibenzanthracene, 3:4-benzpyrene and methylcholanthrene. The increase in the incidence of skin tumors in mice following the application of mouse fat to the skin before tarring, as reported by Watson and Mellanby, 2 led us to investigate the effect of a petroleum ether extract of mouse tissues as a solvent for 3:4-benzpyrene in the production of connective tissue sarcoma. The extract was prepared by refluxing fresh minced mouse carcasses, from which the stomach and intestines had been excised, with petroleum ether (maximum boiling point 50°C) for 16 hours. The petroleum ether was removed by distillation under reduced pressure. The resulting mixture was turbid, yellow and oily at 37°C. A gray-white, greasy, amorphous precipitate formed on cooling. The whole extract consisted largely of neutral fats and free fatty acids. Sesame oil and colloidal solutions of 3:4-benzpyrene were also used. The colloidal material was prepared by the gelatin method of Boyland. 3 Each injection, representing 0.25 mg benzpyrene, was made in the subcutaneous tissues. Three groups of 50 C57 black mice received a single injection of 3:4-benzpyrene in the inguinal region dissolved in sesame oil, petroleum ether extract of mouse carcasses or as a colloidal solution. In a fourth group of 50 mice, each animal received a single injection of each of the 3 solutions. All of the mice were obtained from the Roscoe B. Jackson Memorial Laboratory and were 5 to 6 weeks old when the injections were made. They were observed once weekly. The time when a progressively growing mass was first noted was taken as the appearance time of the tumor.

Obliteration of Vasoconstrictor Gradient in the Extremities Under Nitrous Oxide-Oxygen, Ether, and Tribromethyl Alcohol Anesthesias.

Recent studies of peripheral vascular diseases have brought out the importance of differentiating the element of spasm from that of organic occlusion. Vasoconstriction can be demonstrated in the extremities of most individuals with normal blood vessels by measuring the surface temperatures. This action is present in varying amounts depending on the interplay of environmental conditions and the nervous mechanism. It possesses a definite gradient 1 so that it usually begins about the knee and progressively increases distally. Consequently the toes are normally the coldest parts of the lower extremity. These surface temperature differences can under certain conditions be made to disappear. In a series of 22 individuals with normal vessels it was found that this took place when the lumbar sympathetic fibres were paralyzed by spinal anesthesia. All surface temperatures of the extremities came to approximately the same level, with a variation of ±1.7°C. from the mean. This evidently represents a condition of physiological vasodilatation in the vessels of the extremities and we have called it “the normal vasodilatation level.” Its importance consists in that it permits an accurate estimate of the degree of spasm in any given case of vascular disease. The failure to react to the normal level in the latter signifies the presence of organic occlusion, the degree of which is measured by subtracting the maximum temperature achieved from the normal vasodilatation level. Having established the response to known regional sympathetic paralysis, we now report the effect of certain general anesthetics upon the vasoconstrictor gradient in order to simplify if possible the methods for gaining this information. We have found that nitrous oxide-oxygen, ether, and tribromethyl alcohol individually in anesthetic doses will completely obliterate the vasoconstrictor gradient.

Effect of Methylcholanthrene on Latent Period of Breast Tumors in Dilute Brown Mice.

The production of breast tumors in non-susceptible female mice of strains IF, CBA, JK, and NH by subcutaneous injection of methylcholanthrene was reported almost simultaneously in England 1 and in this country. 2 Observations in this laboratory also indicate that methylcholanthrene may affect the production of mammary carcinoma in a strain of mice that is known to develop the tumors spontaneously. Breeding female dilute brown (Little dba) mice have a high incidence of spontaneous mammary carcinoma. 3 Subline 212, on which our experiments were performed, has a lower incidence of breast tumors than other members of the strain. Forty-two identified breeding female mice of this line have been observed for at least one year. Fourteen of them developed one or more spontaneous breast tumors when 250 to 475 days old. The average latent period was 371.0 days. Most dilute brown mice died of leukosis if they were painted with methylcholanthrene solutions. 4 The carcinogen was applied to the unepilated skin twice weekly with a No. 6 camels hair brush. The site was changed with each painting in the following order: head, left hind leg, right hind leg, left foreleg, right foreleg, sacral region, abdomen, interscapular region, anterior thorax. None of the male mice that were painted developed breast tumors. Thirteen of 65 breeding females of line 212 that were treated with methylcholanthrene had one or more mammary carcinomata. (Table I.) They appeared between the 106th and 268th day of life. The average latent period for these tumors was 181.3 days. The duration of painting varied. No breast cancer was found among 75 virgin females that were treated similarly. The gross and microscopic appearance of the breast tumors was characteristic.

Specificity of paper partition chromatography for analysis of free amino acids in unhydrolyzed urine.

Summary The number of free amino acids found in unhydrolyzed urine by paper partition chromatography is less than that indicated by microbiological assay. No discrepancy is apparent between the methods when hydrolyzed urines are analyzed. As the sensitivities of the two methods are comparable, it is suggested that microbiological techniques are not as specific as the chromatographic procedure for the detection of urinary amino acids in the uncombined state.

THE 9-9-9 PLAN FOR INTERNSHIPS AND RESIDENCIES

To the Editor:— The medical services of the Army and Navy are justly proud of the superb health record of our armed forces and of the even more remarkably low mortality rate in wounded soldiers and sailors. Part of this magnificent performance is due, of course, to the efficient organization of the medical services of the armed forces. A large share has resulted from the advances in medical knowledge of the past twenty-five years. It seems probable, however, that the major element in the achievements of the military medical services is the high standard of medical education in this country during the past quarter century. The doctors now serving the nation in a military capacity are almost all graduates of modern schools and many have had excellent opportunities for postgraduate education. Unless the men coming into active service know the fundamental principles of medicine, have been taught to keep abreast

Perforation of a gall stone into the stomach with resulting pyloric obstruction: Case report with gastroscopic and surgical findings

A case of gall stone acting as a foreign body in the stomach is reported. The clinical, roentgenological, gastroscopic and surgical findings are described.