THE FINE STRUCTURE OF CLOTS FORMED FROM PURIFIED BOVINE FIBRINOGEN AND THROMBIN: A STUDY WITH THE ELECTRON MICROSCOPE.

1. A technique has been described for the preparation of clots from purified fibrinogen and thrombin of bovine origin which are suitable for study with the electron microscope. Experiments have been carried out to compare the fine structure of clots prepared at various values of pH.

THE ENHANCING EFFECT OF CONCURRENT INFECTION WITH PNEUMOTROPIC VIRUSES ON PULMONARY TUBERCULOSIS IN MICE.

The course of pulmonary tuberculosis in the mouse appears to be accelerated as a result of concurrent infection of the lung with either of two pneumotropic viruses. This effect is obtained with virus inocula sufficiently small as to induce little or no definite viral pneumonia.

THE NUCLEOPROTAMINE OF TROUT SPERM.

The nucleoprotamine of trout sperm can be extracted completely with 1 M sodium chloride. On reducing the salt concentration to 0.14 M, physiological saline, the nucleoprotamine precipitates in long, fibrous strands.

THE HISTOPATHOLOGY OF PROGRESSIVE MUSCULAR DYSTROPHY AS REVEALED BY ULTRAVIOLET PHOTOMICROGRAPHY.

Results have been presented of the application of a simplified technique of ultraviolet photomicrography to a study of the specific lesions in muscle in subjects with progressive muscular dystrophy. An exact description of the histological changes occurring in this syndrome, as revealed by photomicrographs in ultraviolet light, is difficult at this time because of the lack of an adequate system of nomenclature. Attention has been drawn, however, to lesions of consistent character, found in sections of muscle removed at biopsy, which appear to be specific for the disease.

INTERFERENCE BETWEEN THE INFLUENZA VIRUSES : II. THE EFFECT OF VIRUS RENDERED NON-INFECTIVE BY ULTRAVIOLET RADIATION UPON THE MULTIPLICATION OF INFLUENZA VIRUSES IN THE CHICK EMBRYO.

Influenza A or influenza B virus rendered non-infective by ultraviolet radiation was found to be capable of producing interference with the multiplication of active influenza viruses in the chick embryo. Certain temporal and quantitative relationships affecting the interference phenomenon with this host-virus system were studied. An hypothesis of the mechanism of interference between the influenza viruses is proposed and discussed.

THE LS-ANTIGEN OF VACCINIA : IV. CHEMICAL ANALYSIS OF LS AND THE EFFECT OF CHYMOTRYPSIN ON LS.

Pure LS-antigen of vaccinia contains 15.8 per cent N and 50.6 per cent C.

SOME CONSTITUENTS OF ELEMENTARY BODIES OF VACCINIA.

Treatment of elementary bodies of vaccinia with dilute solutions of sodium hydroxide resulted in the extraction of certain soluble materials accounting for half of the dry weight of the virus. Elementary bodies contained about 0.4 per cent inorganic phosphorus, practically all of which occurred in the form of a nucleoprotein containing thymus nucleic acid.

STUDIES ON MENINGOCOCCUS INFECTION : X. A FURTHER NOTE ON THE PRESENCE OF MENINGOCOCCUS PRECIPITINOGENS IN THE CEREBROSPINAL FLUID.

Precipitin tests have been carried out on spinal fluid from cases of meningococcal and other forms of meningitis, with monovalent anti-meningococcus horse serum of high titer. Using such a test it has been possible within 2 hours to diagnose and type cases of Type I and Type II meningococcal meningitis. In a certain number of cases fluids which were negative when first drawn became positive after standing for 1 or 2 days at 37 degrees C.

THE REDUCING GROUPS OF PROTEINS.

1. Intact, unhydrolyzed proteins possess in addition to SH groups other reducing groups which can be oxidized by ferricyanide. 2.

SULFHYDRYL AND DISULFIDE GROUPS OF PROTEINS : III. SULFHYDRYL GROUPS OF NATIVE PROTEINS-HEMOGLOBIN AND THE PROTEINS OF THE CRYSTALLINE LENS.

Hemoglobin and the proteins of the crystalline lens contain active SH groups while in the native state, the number of active groups increasing as the pH rises. All the SH groups of denatured globin and of the denatured lens proteins are active at a pH so low that practically none of the SH groups of native hemoglobin and of native lens protein are active. The effect of denaturation on the SH groups of a protein is to extend towards the acid side the pH range of their activity.

SULFHYDRYL AND DISULFIDE GROUPS OF PROTEINS : II. THE RELATION BETWEEN NUMBER OFSH AND S-S GROUPS AND QUANTITY OF INSOLUBLE PROTEIN IN DENATURATION AND IN REVERSAL OF DENATURATION.

1. In native egg albumin no SH groups are detectable, whereas in completely coagulated albumin as many groups are detectable as are found in the hydrolyzed protein. In egg albumin partially coagulated by heat the soluble fraction contains no detectable groups, and the insoluble fraction contains the number found after hydrolysis.

ISOLATION OF POLIOMYELITIS VIRUS FROM THE NASOPHARYNX.

A single example of mild illness diagnosed as suspected abortive poliomyelitis is described in which the virus of poliomyelitis was recovered from the nasopharynx by three different methods. Failure to recover virus from a total of twenty-six cases diagnosed as suspected or abortive poliomyelitis and fourteen contacts is also reported. The original material from the nasopharynx of the positive case proved unusually infective for the monkey, apparently even more so than are the majority of suspensions of spinal cords from fatal human cases of poliomyelitis.

SULFHYDRYL AND DISULFIDE GROUPS OF PROTEINS : I. METHODS OF ESTIMATION.

1. Methods have been described for reducing protein S-S groups, for oxidizing protein SH groups, and for estimating protein S-S and SH groups. 2.

PROTEIN COAGULATION AND ITS REVERSAL : IMPROVED METHODS FOR THE REVERSAL OF THE COAGULATION OF HEMOGLOBIN.

The coagulation of hemoglobin is probably reversible. Several methods are described for preparing soluble crystalline hemoglobin from hemoglobin denatured by HCl or trichloracetic acid. The yield is about 75 per cent.

PROTEIN COAGULATION AND ITS REVERSAL : THE REVERSAL OF THE COAGULATION OF HEMOGLOBIN.

1. The preparation from completely coagulated hemoglobin of crystalline soluble hemoglobin is described. 2.

A STUDY OF THE GENERALIZATION OF VACCINE VIRUS FROM ENHANCED SKIN LESIONS.

Rabbits bearing very intensive skin lesions resulting from the intracutaneous injection of neurovirus plus testicular extract show typical histological alterations in the gonads, suprarenals, liver, spleen, lung, lymph nodes, and bone marrow. Similar but less wide-spread alterations are found after intravenous injection of neurovirus. Although testicle extract injected intracutaneously with neurovirus has a marked enhancing action upon the activity of the latter, the same mixture injected intravenously yields no sign of any such enhancement.

EXPERIMENTS ON THE VISIBILITY OF THE POLYHEDRAL VIRUSES.

With the techniques employed we have not been able to detect any qualitative differences between the particles visible in normal blood and in blood from cases of wilt disease and grasserie. Of the two conditions we can speak more definitely in the case of grasserie, because this we have studied quantitatively as well, that is to say, the particles visible microscopically and ultramicroscopically have been counted without bringing to light any marked difference between normal and diseased blood. This leads us to believe that the virus of wilt disease is probably invisible, and the virus of grasserie almost certainly so, when studied with the optical equipment that we have used, and that further evidence will be necessary before one can accept the chlamydozoa or the Borrellina as the active etiological agents.

A STUDY OF THE MECHANISM OF NUCLEINATE-INDUCED LEUCOPENIC AND LEUCOCYTIC STATES, WITH SPECIAL REFERENCE TO THE RELATIVE ROLES OF LIVER, SPLEEN, AND BONE MARROW.

The leucopenia induced by sodium nucleinate has been followed by repeated counts made simultaneously from the blood of a peripheral vein and from the internal organs, combined with a study of histological sections of the same organs taken with the counts. Measurements with the oncometer of changes in volume of the spleen have been correlated with the leucopenia and the leucocytosis following sodium nucleinate. It has thus been determined that the leucopenia is not the result of a vasomotor phenomenon, or of a change in blood volume, nor is it secondary to a retention of the white cells in the capillaries of lung or liver; it is due to the accumulation of neutrophilic leucocytes in the parenchyma of the spleen.

ULTRA-VIOLET LIGHT AND VACCINE VIRUS : II. THE EFFECT OF MONOCHROMATIC ULTRA-VIOLET LIGHT UPON VACCINE VIRUS.

Under the experimental conditions described in the present paper, it was found that the amount of energy required to kill staphylococci at single wave-lengths in the active ultra-violet region was approximately the same as that necessary to inactivate vaccine virus.

ULTRA-VIOLET LIGHT AND VACCINE VIRUS : I. THE REACTION OF IRRADIATED SKIN TO VACCINE VIRUS.

Rabbit skin treated for a few minutes with ultra-violet light and then inoculated at once with vaccine virus is less susceptible to the action of the virus than is untreated skin. If 24, 48, or 72 hours elapse between the time of irradiation and inoculation, the treated skin appears to be more susceptible than is untreated skin. Skin repeatedly exposed to ultra-violet light is less susceptible to the action of vaccine virus than is non-irradiated skin.

GROWTH AND PERSISTENCE OF FILTERABLE VIRUSES IN A TRANSPLANTABLE RABBIT NEOPLASM.

Virus III and vaccine virus multiply in a transplantable rabbit tumor of epithelial origin; are carried along with the tumor through an indefinite number of transplants; and despite an immunity developed by the rabbit host survive longer in the tumor than when injected into the testicles of normal rabbits.

THE PENETRATION OF BACTERIA THROUGH CAPILLARY SPACES : IV. A KINETIC MECHANISM IN INTERFACES.

The dark-field microscope may be used to observe directly the characteristics of composite films. The liquid phases, one or both of them containing suspended solid particles as test objects (in these experiments bacteria were used), are spread between slide and cover-glass and examined with any desired lenses. The liquid-liquid interfaces appear as bright lines and the solid particles as shining motes.

THE EFFECT OF ANESTHESIA AND OF SEDATIVES ON THE SERUM THERAPY OF EXPERIMENTAL BOTULISM.

When guinea pigs are fed large amounts of botulinus toxin, they develop symptoms of intoxication within 6 hours and die usually within 12 hours after the feeding of toxin. If very large amounts of toxin are introduced intraperitoneally, the animals may show symptoms of intoxication at the end of the 1st hour and die usually within 2 hours following the administration of toxin. If these animals are placed under anesthesia following the administration of toxin, the intoxication proceeds much more slowly.

ON THE ANTIGENIC PROPERTIES OF HEMOGLOBIN.

Sera produced by immunization with crystalline oxyhemoglobin react species-specifically with hemoglobin solutions. Evidence is presented that in this reaction the hemoglobin itself is the active substance. Conversion of oxyhemoglobin into methemoglobin, carbon-monoxy hemoglobin, or cyanhemoglobin does not alter the response to the precipitating immune serum.

THE INFLUENCE THAT SERUM EXERTS UPON TRYPANOSOMES, WITH SPECIAL REFERENCE TO ITS USE FOR EXPERIMENTS IN VITRO WITH ATOXYL AND PARAMINO-PHENYLARSENOXYD.

1. Serum of various animals preserves the motility of nagana trypanosomes better and longer than salt solution. 2.