Homologous Immune Serum Research Articles

ENHANCEMENT OF THE OPSONIZING AND AGGLUTINATING POWERS OF ANTIPNEUMOCOCCUS SERUM BY SPECIFIC PRECIPITATING SERUM

1. No demonstrable antiopsonins are formed in rabbits following the intravenous injection of monovalent pneumococcus horse sera, Types I, II, and III. 2. The serum of rabbits injected with immune pneumococcus horse serum, Type I, II, or III, or with normal horse serum, when mixed in the proportion of 1:4 with Type I or Type II pneumococcus horse serum, can greatly augment, in vitro, the opsonization and agglutination of Type I and Type II pneumococci by the homologous immune horse sera. No similar effect is obtained with Type III serum and pneumococci. 3. The increase in opsonization and agglutination is dependent upon (a) specific sensitization of the pneumococci by the homologous immune serum and (b) the presence of the precipitating serum. In the absence of sensitization, as when a heterologous or normal horse serum is employed, opsonization and agglutination do not occur, even though a precipitating mixture is provided. The substitution of normal rabbit serum for the precipitating rabbit serum gives opsonization and agglutination in dilutions slightly higher than are effected with salt solution only, due possibly to the more favorable medium created for the leucocytes by the addition of 25 per cent of whole rabbit serum. 4. Different methods of combining the immune horse serum, precipitating rabbit serum, and pneumococci yield very similar results, preliminary sensitization of the bacteria before precipitation, or precipitation in the rabbit-horse serum mixture before the addition of the pneumococci for sensitization causing little if any difference in result from that obtained when immune horse serum, precipitating rabbit serum, and pneumococci are all mixed and incubated together. 5. This increased opsonization in the test-tube does not seem to be paralleled by increased protective power, or at any rate such protection is not readily demonstrated.

METHODS FOR THE DETERMINATION OF PNEUMOCOCCUS TYPES

The determination of pneumococcus types in lobar pneumonia is of value in the field of prognosis and as a prerequisite for specific serum therapy. The method for the determination of types should be as rapid as possible and a standard technique should be employed. The most satisfactory method is by the intraperitoneal inoculation of a mouse with the patient's sputum, by which means a rapid and abundant growth of the pneumococcus is obtained and secondary organisms are rapidly eliminated in most instances. The diagnosis of type is made directly on the peritoneal exudate. Certain factors in the method commonly used have interfered with the rapid determination of types in an appreciable number of cases, notably the growth of other organisms in the peritoneal exudate together with the pneumococcus, and some confusion has arisen because occasional strains of pneumococci have been encountered that show cross agglutination reactions when undiluted immune serum is used. Such reactions have been shown to be due to a limited zone of non-specific immunity and they in no way invalidate the classification of the pneumococci into sharply defined immunological groups. The optimum dilutions of serum have been determined that will agglutinate all type strains of pneumococci and fail to cause any cross agglutination reactions when mixed with equal amounts of pneumococcus cultures and incubated for I hour at 37 degrees C. They are a 1:20 dilution of Serum I, a 1:20 dilution of Seruifa II, and a 1:5 dilution of Serum III. For the diagnosis of Subgroup II pneumococci undiluted Type II serum is required. To obviate the other difficulties of the method commonly used a new method for the determination of types has been devised. It depends upon the fact that there is produced by the growth of the pneumococcus a soluble substance which is present in the peritoneal exudate of the mouse in sufficient quantity to give a specific precipitin reaction with the homologous immune serum. The precipitin method can be used in all instances in which the determination of types by the agglutination method is possible, and it possesses certain distinct advantages which make it available when the agglutination method is impracticable. It is of particular value as a time-saving device in those instances where the presence of other organisms together with the pneumococcus in the peritoneal exudate causes a delay of 18 hours or more before the type of pneumococcus can be definitely established. It is therefore recommended as the method of choice in all cases. If desired, both the agglutination and precipitin methods may be applied to the same specimen of peritoneal washings.

IMMUNOLOGICAL STUDIES ON PURE CULTURES OF VARIOUS SPIROCHETES

IMMUNOLOGICAL STUDIES ON PURE CULTURES OF VARIOUS SPIROCHETES

VARIATIONS IN THE PNEUMOCOCCUS INDUCED BY GROWTH IN IMMUNE SERUM

1. The growth of virulent pneumococci in homologous immune serum produces (a) variations in agglutinability, (b) decrease in virulence, (c) inhibition of capsule formation, (d) increase in phagocytability with normal serum, and (e) change in absorption power and antigenic properties. 2. Reversion to the original type in these changed forms takes place upon animal passage.

The effects of vaccine sensitised with homologous immune serum, as compared with those of a non‐sensitised vaccine: An experimental study

The effects of vaccine sensitised with homologous immune serum, as compared with those of a non‐sensitised vaccine: An experimental study

CHEMO-IMMUNOLOGICAL STUDIES ON LOCALIZED INFECTIONS

Virulent pneumococci injected into the cranial or spinal cavities of monkeys produce constantly a meningitis closely resembling pneumococcus meningitis in man, except that the experimental disease pursues a more rapid course to the invariable death of the untreated animal. An homologous immune pneumococcus serum injected into the spinal canal exerts a restraining influence upon the disease to the extent that when employed early it prevented, exceptionally, the occurrence of infection and thus saved the life of the animal, and when given later it at first retarded the disease but subsequently exerted no beneficial action and was powerless to save life. A mixture of sodium oleate, immune serum, and boric acid exerted regularly a more powerful action than immune serum alone, and not only prevented the occurrence of infection but also, when administered repeatedly, arrested the progress of an actually established infection and led, often, to the enduring and perfect recovery of the inoculated animal. It is proposed to employ a similar mixture in the direct treatment of pneumococcic meningitis and possibly of still other accessible local pneumococcic infections in man.

A Contribution to the Bacteriology of Diphtheria

Interest in the bacteriology of diphtheria has been directed to the study of the identity of Hofmann's bacillus and the group of pseudo-diphtheria and their relation to the true diphtheria bacillus; to study of methods and means whereby a virulent bacillus may be differentiated from the non-virulent in practical culture work; and to the study of the question of carriers, from both a bacteriological and public health point of view. Ever since the discovery of Hofmann's bacillus efforts have been made to establish its relation to the true diphtheria bacillus. Various culture media, differential stains, and passage through various animals have been tried in the endeavor to make it virulent or change its morphology. Similar efforts have been made to convert a typical diphtheria bacillus into the Hofmann type. The results reported have not been uniform, although present indications point to the fact that the Hofmann bacillus possesses such characteristics as to justify its recognition as a separate entity. In my paper on A Study of Diphtheria Bacilli with Special Reference to Complement-Fixation Reactions, ' however, it has been shown by complement-fixation tests with homologous antigens and immune sera of different types of diphtheria bacilli from varied clinical sources, including a true Hofmann bacillus, that all of these bacilli are closely related and that the Hofmann bacillus belongs to the group of diphtheria bacilli, but that as a result of various influences the latter has been changed in its chemical reactions, structure, and virulence so as to give it constant and more or less new characteristic features which are transmitted through a number of generations. Between this decided example of mutation and the parent or true diphtheria bacilli are many