Ritka szisztémás gyógyszer-interakció: timololtartalmú szemcsepp és lerkanidipintabletta együttes alkalmazása során ismétlődően jelentkező syncope

Abstract:

The control and planning of the treatment of hypertensive patients need specific attention. As regards concomitant diseases and treatments, glaucoma and the use of eye drops should be taken into consideration. The ingredients of the administered eye drops get through the nasolacrimal canal and can be absorbed by the nasal mucosa. Because of the lack of enterohepatic ‘first pass’ effect, they can act systemically – like after intravenous administration. This way they can cause systemic side effects. The authors present a case of a patient, too, who was examined and medically checked regularly for years with negative results because of repeated syncope. It became clear only at the Hypertension Centre that the timolol-containing combined eye drops caused the symptoms. The authors draw attention to the fact that in the case of systemic side effects which can be connected to beta-blocking agents (blood pressure fall, bradycardia, breathing disturbance, depression), the role of the eye drops should be taken into consideration. At the same time, the possibility of the systemic drug interactions should not be forgotten either. The interaction with dihydropyridine-type calcium-channel blockers can be of great importance. In these cases, after consultation with an ophthalmologist, the glaucoma treatment with eye drops containing beta-blockers should be modified. Orv Hetil. 2019; 160(8): 309–313.

Accuracy of machine learning classifiers using bilateral data from a Scheimpflug camera for identifying eyes with preclinical signs of keratoconus

PURPOSE

To describe the topographic and tomographic characteristics of normal fellow eyes of unilateral keratoconus cases and to evaluate the accuracy of machine learning classifiers in discriminating healthy corneas from the normal fellow corneas.

SETTING

Department of Ophthalmology, Semmelweis University, Budapest, Hungary.

DESIGN

Retrospective case-control study.

METHODS

Patients with bilateral keratoconus (keratoconus group), clinically and according to the keratoconus indices of the Pentacam HR Scheimpflug camera; normal fellow eyes of patients with unilateral keratoconus (fellow-eye group); and eyes of refractive surgery candidates (control group) were compared. Tomographic data, topographic data, and keratoconus indices were measured in both eyes using the Scheimpflug camera. Receiver operating characteristic (ROC) analysis was used to assess the performance of automated classifiers trained on bilateral data as well as individual parameters to discriminate fellow eyes of patients with keratoconus from control eyes.

RESULTS

Keratometry, elevation, and keratoconus indices values were significantly higher and pachymetry values were significantly lower in keratoconus eyes than in fellow eyes of unilateral keratoconus cases (P < .001). These fellow eyes had significantly higher keratometry, elevation, and keratoconus index values and significantly lower pachymetry values than control eyes (P < .001). Automated classifiers trained on bilateral data of index of height decentration had higher accuracy than the unilateral single parameter in discriminating fellow eyes of patients with keratoconus from control eyes (area under ROC 0.96 versus 0.88).

CONCLUSION

Automatic classifiers trained on bilateral data were better than single parameters in discriminating fellow eyes of patients with unilateral keratoconus with preclinical signs of keratoconus from normal eyes.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Lacosamide diminishes dryness-induced hyperexcitability of corneal cold sensitive nerve terminals

Lacosamide is an anti-epileptic drug that is also used for the treatment of painful diabetic neuropathy acting through voltage-gated sodium channels. The aim of this work was to evaluate the effects of acute application of lacosamide on the electrical activity of corneal cold nerve terminals in lacrimo-deficient guinea pigs. Four weeks after unilateral surgical removal of the main lachrimal gland in guinea pigs, corneas were excised and superfused in vitro at 34°C for extracellular electrophysiological recording of nerve terminal impulse activity of cold thermosensitive nerve terminals. The characteristics of the spontaneous and the stimulus-evoked (cooling ramps from 34°C to 15°C) activity before and in presence of lacosamide 100µM and lidocaine 100µM were compared. Cold nerve terminals (n=34) recorded from dry eye corneas showed significantly enhanced spontaneous activity (8.0±1.1 vs. 5.2±0.7imp/s; P<0.05) and cold response (21.2±1.7 vs. 16.8±1.3imp/s; P<0.05) as well as reduced cold threshold (1.5±0.1 vs. 2.8±0.2 Δ°C; P<0.05) to cooling ramps compared to terminals (n=58) from control animals. Both lacosamide and lidocaine decreased spontaneous activity and peak response to cooling ramps significantly (P<0.05). Temperature threshold was increased by the addition of lidocaine (P<0.05) but not lacosamide (P>0.05) to the irrigation fluid. In summary, the application of lacosamide results in a significant decrease of the augmented spontaneous activity and responsiveness to cold of corneal sensory nerves from tear-deficient animals. Based on these promising results we speculate that lacosamide might be used to reduce the hyperexcitability of corneal cold receptors caused by prolonged ocular surface dryness due to hyposecretory or evaporative dry eye disease.

Corneal Sensitivity and Dry Eye Symptoms in Patients with Keratoconus

PURPOSE

To investigate corneal sensitivity to selective mechanical, chemical, and thermal stimulation and to evaluate their relation to dry eye symptoms in patients with keratoconus.

METHODS

Corneal sensitivity to mechanical, chemical, and thermal thresholds were determined using a gas esthesiometer in 19 patients with keratoconus (KC group) and in 20 age-matched healthy subjects (control group). Tear film dynamics was assessed by Schirmer I test and by the non-invasive tear film breakup time (NI-BUT). All eyes were examined with a rotating Scheimpflug camera to assess keratoconus severity.

RESULTS

KC patients had significatly decreased tear secretion and significantly higher ocular surface disease index (OSDI) scores compared to controls (5.3±2.2 vs. 13.2±2.0 mm and 26.8±15.8 vs. 8.1±2.3; p<0.001). There was no significant difference in NI-BUT between the two groups (KC: 9.8±4.8 vs. control: 10.7±3.8; p>0.05). The mean threshold for selective mechanical (KC: 139.2±25.8 vs. control: 109.1±24.0 ml/min), chemical (KC: 39.4±3.9 vs. control: 35.2±1.9%CO2), heat (KC: 0.91±0.32 vs. control: 0.54±0.26 Δ°C) and cold (KC: 1.28±0.27 vs. control: 0.98±0.25 Δ°C) stimulation in the KC patients were significantly higher than in the control subjects (p<0.001, for all parameters). No correlation was found between age and mechanical, chemical, heat or cold thresholds in the patients with KC (p>0.05), whereas in the control subjects both mechanical (r = 0.52, p = 0.02), chemical (r = 0.47, p = 0.04), heat (r = 0.26, p = 0.04) and cold threshold (r = 0.40, p = 0.03) increased with age. In the KC group, neither corneal thickness nor tear flow, NI-BUT or OSDI correlated significantly with mechanical, chemical, heat or cold thresholds (p>0.05 for all variables).

CONCLUSIONS

Corneal sensitivity to different types of stimuli is decreased in patients with keratoconus independently of age and disease severity. The reduction of the sensory input from corneal nerves may contribute to the onset of unpleasant sensations in these patients and might lead to the impaired tear film dynamics.

The Effect of Tear Supplementation on Ocular Surface Sensations during the Interblink Interval in Patients with Dry Eye

PURPOSE

To investigate the characteristics of ocular surface sensations and corneal sensitivity during the interblink interval before and after tear supplementation in dry eye patients.

METHODS

Twenty subjects (41.88±14.37 years) with dry eye symptoms were included in the dry eye group. Fourteen subjects (39.13±11.27 years) without any clinical signs and/or symptoms of dry eye were included in the control group. Tear film dynamics was assessed by non-invasive tear film breakup time (NI-BUT) in parallel with continuous recordings of ocular sensations during forced blinking. Corneal sensitivity to selective stimulation of corneal mechano-, cold and chemical receptors was assessed using a gas esthesiometer. All the measurements were made before and 5 min after saline and hydroxypropyl-guar (HP-guar) drops.

RESULTS

In dry eye patients the intensity of irritation increased rapidly after the last blink during forced blinking, while in controls there was no alteration in the intensity during the first 10 sec followed by an exponential increase. Irritation scores were significantly higher in dry eye patients throughout the entire interblink interval compared to controls (p<0.004). NI-BUT significantly increased after HP-guar (p = 0.003) but not after saline drops (p = 0.14). In both groups, either after saline or HP-guar the shape of symptom intensity curves remained the same with significantly lower irritation scores (p<0.004), however after HP-guar the decrease was significantly more pronounced (p<0.004). Corneal sensitivity to selective mechanical, cold and chemical stimulation decreased significantly in both groups after HP-guar (p<0.05), but not after saline drops (p>0.05).

CONCLUSION

Ocular surface irritation responses due to tear film drying are considerably increased in dry eye patients compared to normal subjects. Although tear supplementation improves the protective tear film layer, and thus reduce unpleasant sensory responses, the rapid rise in discomfort is still maintained and might be responsible for the remaining complaints of dry eye patients despite the treatment.

Permanent alterations of the L-forms of proteus and salmonella under various conditions

L-forms obtained from three strains of Proteus and from one strain of Salmonella have been kept for 15 to 20 years by weekly or monthly transfers on agar plates containing penicillin. The morphology and growth requirements of these strains have changed. They now grow abundantly on the surface of agar and in broth. The cultures consist of large bodies, small granules, and transitional forms. These organisms are more resistant to distortion and stain more deeply than organisms of the usual L-forms. In broth and to a lesser extent on agar, branching filaments develop, on the ends of which both the large, round organisms and small organisms are produced. The filaments are a transitional stage in the development of the cultures. Usual bacillary forms were not present in the culture and did not appear in successive transfers in the absence of penicillin. Bacilli reappeared on exposure of the L cultures to the influence of a spore-bearing bacillus. A similar transformation of L-forms has also been observed developing within a short time in recently isolated A and B type L cultures of one Proteus strain during the process of reversion to the bacterial form. The altered cultures are fixed in a stage of transition between the B type L-form and the regular bacteria.

Observations suggesting the development of streptococci from pleomorphic filamentous gram negative bacteria

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Alterations of the L-forms of a sporebearing bacillus

A large pleomorphic gram-negative bacillus developed as a contaminant on blood-agar. Spores were formed in one culture. L-forms were produced with penicillin on blood-agar with 2.5% NaCl; they grew well when transplanted to agar with 0.5% NaCl. After several transplants and long incubation of the L-forms without penicillin, in three transplants small gram-negative pleomorphic bacilli grew, but no L-forms. This occurred once on blood-agar and twice on 30% gelatin. The growth obtained from these small bacilli was similar in morphology and in the physical properties of the organisms to the altered L-forms of Proteus and Salmonella. Multiplication of the pleomorphic organisms and development of branching filaments from the round forms was apparent. The original large gram-negative bacillus was regularly recovered from the L-forms, and was recovered several times from the descendants of the small bacilli. These observations are essentially similar to those made with L-forms of Proteus and with an L-form studied in 1952, indicating alterations in L-forms of bacteria which do not produce B type L-forms.

Morphology and reproductive processes of the L forms of bacteria. II. Comparative study of L forms and Mycoplasma with the electron microscope

Representative electron micrographs, from the study of eight strains of L forms and one strain of Mycoplasma, are presented. A- and B-type L forms were derived from two strains of Proteus, two other L forms were derived from a diphtheroid and from a staphylococcus strain, and two strains (designated as LX) were isolated from L forms derived from a group A beta-hemolytic streptococcus and from a staphylococcus. The Mycoplasma strain was isolated from goats. Sections were made of young colonies grown within agar and from parts of surface colonies embedded in the agar. B-type L colonies of Proteus were produced by inoculation of bacteria into media containing penicillin. The large bodies developing from the bacteria and the organisms in B-type L colonies of Proteus, like the parent bacteria, had a cell wall consisting of a plasma membrane and an outer cell wall. The loss of rigidity in the cell wall indicated an alteration in its structure. The A-type L cultures of Proteus consisted of irregular branching masses extending in several directions, of small dense organisms corresponding to the elementary corpuscles present in cultures of Mycoplasma, and of intermediary forms. In contrast to the B-type, all organisms in the A-type colonies were surrounded by a single unit membrane corresponding to the plasma membrane of bacteria. The structures inside the cell membrane, both in the A- and B-type, seemed to correspond to the structure of the parent bacteria, which contained ribosomes and threads of DNA. The elementary corpuscles formed chains and filaments, and, apparently, these corpuscles took part in the multiplication by gradual enlargement. The organisms seen in the cultures of all L forms and Mycoplasma studied, except in the B-type L forms of Proteus, corresponded in size, shape, and structure, as well as in the development of elementary corpuscles, to the organisms in the A-type L form of Proteus. In contrast to the spherical organisms usually seen in broth cultures, the organisms in young cultures of Mycoplasma, which were grown within the agar, were similar in morphology, as well as in the discernible structure of the organisms, to L forms. Significant morphological and structural differences were not apparent between the L forms and Mycoplasma (in cultures grown within agar media) under the conditions of this investigation.

Morphology and reproductive processes of the L forms of bacteria. I. Streptococci and staphylocci

The production of L forms from cocci, the conditions necessary for their multiplication, and their morphology have been studied for several years. In each strain studied, only a few organisms produced L forms. Transplants from these grew poorly at first, and growth on agar and in broth became abundant only after long cultivation. Multiplication in the form of small granules was observed only when the organisms were embedded in agar and occasionally in coagulated blood serum. On the surface of hard agar, the organisms increased in size but did not multiply. Abundant growth developed on membrane filters of appropriate size, extending into the filters as branching irregular masses. On gelatin, on most samples of coagulated serum, and on silica gel, the organisms grew to a very large size, and occasionally colonies developed by multiplication of large bodies. This multiplication occurred by irregular enlargement and separation into fragments. Growth in broth and in semisolid agar also occurred by multiplication of large bodies, but, in addition, the development of viable granules was observed inside the large bodies in broth culture. After the L forms began to grow abundantly, their nutritional requirements were simple; they no longer required animal serum. Their ability to multiply and their morphological characteristics depended to a large extent on the physical properties of the environment.

Permanent stained agar preparation of Mycoplasma and of L forms of bacteria

A procedure is described that permits the preparation of permanent stained mounts of Mycoplasma and of bacterial L forms grown on the surface of and within agar media. These preparations are especially useful for making representative photographs. The cultures are fixed with Formalin vapor. Thin slices of agar are stained at elevated temperature between 50 and 60 C and at a low pH, are dried rapidly, and are mounted in Canada balsam. The results with this staining procedure are illustrated by photographs of various strains of Mycoplasma and of bacterial L forms.

Morphology and Nature of the Pleuropneumonia Group of Organisms

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The Flaring up of Injection Sites in Allergic Guinea Pigs

In guinea pigs injected intracutaneously with human serum or turtle egg, a flare-up of the injection site can often be observed after an interval of a few days. This occurs at the time when skin sensitiveness begins to develop usually on the fourth to sixth day. Both the flare at the original site and the skin test at this time are purely of the delayed type and anaphylactic shock cannot be produced in the guinea pigs.

In the reacting flare about the original site of inoculation the tissues show infiltration with mononuclear cells which is characteristic also of the delayed type of skin reaction. It is pointed out that the developing allergy probably plays a rôle in the development of specific tissue reactions in the lesions of certain infectious diseases.

The Participation of Cutaneous Epithelium in Immunity Response

In allergic (contact) dermatitis and certain cases of drug idiosyncrasy, the epithelium of the skin is probably sensitized. The hypersensitiveness of the epithelium develops by contact with the injurious agent in the same manner as the usual forms of hypersensitiveness.

The tuberculin type of skin reactions present many characteristics that suggest the direct participation of the cutaneous epithelium in the reaction. The characteristic necrosis in the reactions is often limited to the epithelium and a thin layer of connective tissue below it. The epithelium is involved early before the macroscopic reaction is strong. The epithelium is often infiltrated with polymorphonuclear leucocytes even in slight tuberculin reactions. The occurrence of necrosis is in no direct connection with the size of the reaction or with the general sensitiveness.

Histological Studies of Hypersensitive Reactions

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Further Attempts to Transfer the Immunological Response of Tuberculous Animals

Three groups of experimental efforts to transfer to other animals the increased immunologic response of tuberculous animals have been described. The transfer of tuberculous omenta or tuberculous peritoneal exudate, a few minutes after the injection of egg-white, to the peritoneal cavity of normal pigs was unsuccessful. Where a similar transfer was made into the peritoneal cavity of a previously infected animal—in a stage of infection in which the injection of egg-white alone does not produce the characteristic effect—irregular positive results were obtained. A simultaneous injection of egg-white and tubercle bacilli was in these guinea pigs often successful.

The experiments suggest that two factors are involved, (a) the effect which the lesion itself produces upon the antigen, and (b) a certain preparation of the organism as a whole occurring during the course of the infection.

Factors Conditioning the Development of the Tuberculin Type of Hypersensitivity

Preliminary treatment with egg-white of a series of animals, thus producing an anaphylactic sensitivieness, before infection with tubercle bacilli and subsequent treatment with egg-white according to methods known to produce a tuberculin type of reaction, apparently prevented in the majority of instances the development of tuberculin-type sensitivity. One-fifth to 0.1 mgm. of egg-white is approximately the minimal single dose required for the constant production of strong tuberculin type of sensitivity. An initial injection of a much smaller amount, however, exerts a marked influence on the effect of injections given at later periods. When successive doses are used in sensitizing the animals, or when repeated skin tests are made, either the anaphylactic or the tuberculin type of sensitivity may develop. Among the factors governing which type of sensitiveness will appear are the intervals between injections, the route of injection not only of the initial but of subsequent doses and the condition of the animal dependent on the state and degree of its infection. Repeated injections in short interval favor the development of anaphylactic type of sensitivity. If the interval after the first injection is long enough for the development of a marked grade of tuberculin type of sensitivity, consecutive injections usually increase the strength of this type of sensitivity. During the first week after intravenous infection with the R1 strain of tubercle bacilli conditions as favorable for the production of the tuberculin type of sensitiveness as those afforded by a strong local infection are not produced. If the intravenous infection is a heavy one the effect appears in contrast to be distinctly inhibitory. It seems fair to conclude that the slight generalized infection which follows a local tuberculous infection has little to do with the effects observed in locally infected guinea pigs.

Comparative Study of the Anaphylactic and Tuberculin Types of Hypersensitiveness

The crystalline egg albumin and egg globulin differ considerably in their relationship to the different manifestations of hypersensitiveness. The crystalline egg albumin tends to sensitize the organism to those manifestations of the hypersensitiveness which are mediated by antibodies. The egg globulin tends to sensitize to those in which the active immunization plays the more important rôle. The difference between the antigens lies in their capacity to produce a different type of sensitization. We find no marked difference between them concerning their capacity to produce antibodies or to elicit the reactions themselves. The observations with crystalline egg albumin and egg globulins present an analogy to the behavior of certain bacterial antigens which we usually find connected either with the tuberculin or with the anaphylactic type of sensitiveness.

We have given a short review of our experiences concerning the capacity of different antigens to produce the tuberculin type of skin sensitiveness. With all innocuous antigens which we tested—as eggwhite and animal sera—we succeeded in producing this sensitiveness. With bacterial antigens we have not so far succeeded in producing it.

Comparative Study of the Anaphylactic and Tuberculin Types of Hypersensitiveness

Tuberculous guinea pigs sensitized with egg white and also with various other antigens often die after intraperitoneal injection in a protracted shock which is similar in many respects to the tuberculin shock. It is of special significance that a strong hemorrhagic reaction develops around the tuberculous lesion. This hemorrhagic reaction is not the result of the special sensitiveness of the lesion, it might be present in any inflammatory area without regard to the origin of the inflammation.

The eggwhite shock differs in two points from the tuberculin shock. The symptoms often begin to develop early after the injection, and in the early phases of the reaction and in the slight reactions usually a drop of temperature is present. These differences are probably connected with the presence of the usual anaphylactic sensitiveness after treatment with eggwhite. When the latter is associated with the tuberculin sensitiveness, the tuberculin shock often presents the same temperature curve and early onset of symptoms as the eggwhite shock.

The capacity to react with severe protracted shock develops later after the treatment than either the tuberculin type of skin sensitiveness or anaphylaxis. We observed it only in actively sensitized guinea pigs, and our experiments to transfer it passively remained unsuccessful. The different manifestations of the hypersensitive condition develop in a large measure independently from each other. The independence of the severe protracted shock from the anaphylactic shock is shown also by the observation that the desensitization to the acute anaphylactic shock does not interfere with the development of the severe protracted shock.

The severe protracted eggwhite shock and tuberculin shock are probably analogous processes; but without a more thorough understanding of the physiologic mechanism of the reaction this conclusion must be regarded as only provisory.

Certain Characteristics of the Infectious Processes in Connection with the Influence Exerted on the Immunity Response

The observations described in this paper inform us concerning important properties of the lesions, with the help of which the production of the tuberculin type of sensitiveness is successful. Twenty-four hours after the injection of a large dose of the R1 strain into the testicle, the injection of eggwhite in the same place produces tuberculin type of sensitiveness. When intraparitoneal injections are used, forty-eight-hour intervals were necessary between the two injections. In the production of the sensitiveness the local reaction at the site of the tubercle bacillus injection played the preponderant rôle because only the injection of eggwhite in this place was effective. The intravenous injection of small doses is without effect. At the stage when we injected the eggwhite an acute inflammatory reaction is present, with large accumulation of leucocytes around the injected bacteria. The typical tissue reaction of tuberculosis is not yet developed. The latter is not a prerequisite of the development of the tuberculin type of sensitiveness.

It was possible to produce a tuberculin type of sensitiveness with the injection of eggwhite into the testicle of guinea pigs infected with smallpox vaccine.

With extensive acute inflammatory processes produced with infusorial earth, tapioca, turpentine, the immunity response of the animals was not influenced. The local reactions produced with the antigenic lipoid substances of the tubercle bacilli also remained without effect.

With the soluble substances of the tubercle bacillus we did not succeed in increasing the antigen response. Different considerations make it improbable that the substances of the bacterium are directly responsible for the influence exerted by the lesions on the immunity response.

We give also a review of unsuccessful experiments in which we tried to transfer passively the increased response toward the antigens with the products of tuberculous lesions.

The Specificity of the Tuberculin Type of Sensitiveness Produced with the Different Protein Substances of the Eggwhite

According to the observations described in this paper the sensitiveness of the tuberculin type produced in guinea pigs with egg globulin, crystalline egg albumin, and ovomucoid is specific to the preparation with which the animals were treated. The specificity of this type of sensitiveness, like that of the anaphylactic sensitiveness, corresponds to the antigen specificity.

The Antigenic Substances of the Tubercle Bacillus

In the filtrates of cultures grown on the synthetic medium of Long, beside the carbohydrate precipitable substance, we can demonstrate the presence of two antigenic substances. They are separated from each other by acid precipitation. Both by the serological reactions and the antibody production these antigens are well differentiated from each other and from the other antigens of the tubercle bacillus. The difference between these two fractions can be observed also concerning the tuberculin reaction in guinea pigs treated with one or the other of these preparations.

The acid-precipitable antigen readily forms antibodies in tuberculous animals which are specific toward this antigen. The acid non-precipitable fractions did not form antibodies reacting with the same preparations or with the acid precipitate and concentrated culture medium, but the sera of the majority of the guinea pigs treated with these preparations gave strong reactions with the bacillary emulsion.

From the observations that neither of the two antigens separated by acid precipitation or their mixture gave a positive reaction with several sera produced with the concentrated culture medium and that the latter did not react with the sera produced with the acid precipitate we draw the conclusion that in the culture medium the antigens which are separated by acid precipitation are united in a higher complex which has a specificity markedly different from that of the isolated antigens, and in the reactions of which the effect of the isolated antigens does not appear. The differences which we found concerning the serological reactions between the culture filtrate of different tubercle bacillus strains are probably caused not by the absence or presence of a certain antigen, but by the differences in the way in which the acid-precipitable part is united to the higher complex.

Probably the above mentioned complex antigen is responsible for the production of antibodies by the concentrated culture medium and the acid filtrate, although this complex often gives no, or gives only a slight, reaction with these sera.

The Technic of Producing the Tuberculin Type of Sensitization with Eggwhite in Tuberculous Guinea Pigs

Several methods are described by which we regularly succeeded in producing a tuberculin type of a sensitiveness with eggwhite in tuberculous guinea pigs. The different methods have this in common that an extensive local lesion is produced, usually with pronounced inflammatory reaction, and the eggwhite is introduced into this lesion.

The Antigenic Substances of the Tubercle Bacillus

In the extracts of tubercle bacillus obtained with alcohol of different strength and with methyl-alcohol we found six different antigens, three of which are well characterized and well separated from the others. The characterization of three others is not definite. It needs further work to establish the nature of the differences between these antigens and as to whether they have different antigen specificity in the usual sense of this word.

From the watery extract, weak NaOH extract, and broth cultures we separated three protein fractions with different antigenic properties and different isoelectric points. These fractions probably contained different protein substances. Our observations indicate that in the protein substances more than these three antigens are present, and especially in certain watery extracts and in the filtrates of liquid media there is present a protein substance which is non-precipitable with acids, has strong tuberculin effect, and the antigenic properties of which are different from those of the other protein antigens.

The antibody production is strongest with intact bacteria and bacillary fragments. There is a distinct difference between the sera obtained with living and with killed bacillus emulsion. Toward the different antigens varying amounts of antibodies are present in these sera, sometimes the protein antibodies predominate, and lipoid antibodies are not formed—or only slightly formed—in other sera the opposite is the case. Toward two antigens antibodies are not produced. Both the watery and the alcoholic extracts produce antibodies, although in slighter amounts than the formed elements. In the sera produced with the lipoid substances a certain amount of protein antibodies is usually present, and the sera obtained with the 75 per cent alcoholic extract contain in abundance the two types of antibodies which are absent in the sera obtained with bacillus emulsion. With the progress of the purification the antigenic effect in vivo with the majority of the antigen preparations largely decreases or disappears. We observed also that in the purified preparation an antigenic effect in vivo appears which was not present in the original extract, and, especially certain protein fractions, produced precipitins in abundance toward the carbohydrate precipitable substance, while the extracts themselves were ineffective. The majority of antigens in conformity with the conception of Zinsser produced antibodies only when in connection with larger complexes in which certain protein substances have probably a preponderant rôle.

The use of tuberculous guinea pigs for the production of antisera was of great help both for the differentiation of the antigens and for the examination of the antigenic effect in vivo.

The Antigenic Substances of the Tubercle Bacillus

Date are given concerning the chemical composition of preparations of antigens 3, 4, 2 and 5. The preparations of antigens 3 and 4 contain large amounts of fatty substances. In the preparations of antigens 2 and 5 only 8 to 10 per cent are present. All preparations contain carbohydrates in varying amounts without apparent connection with the specific properties. The N content of the purified preparations of antigens 3 and 4 is low (0.3 to 0.4 per cent). In the preparations of antigens 2 and 6 which we analyzed it was somewhat higher (1.7 to 3.2 per cent).

From our observations it seems probable that in antigen 3 a specific part containing only little fat is in chemical connection with non-specific lipoid substances. We were not successful in determining the conditions under which the separation of the components occurs regularly. Studying the effect of water and HCl on the ether-solution of antigen 3 we made observations which probably will be of value for a more thorough study of this preparation.

The Antigenic Substances of the Tubercle Bacillus

Guinea pigs sensitized with killed bacteria compared with infected guinea pigs give relatively stronger reactions with the protein substances extracted with weak NaOH from the bacillary bodies than with the filtrate of broth culture.

When groups of tuberculous guinea pigs are treated with different tuberculin preparations with different antigen specificity the skin reactions in each group (compared to the reaction of the other groups) are relatively slighter with the preparations used for the treatment than with the other preparations. These observations show that between different tuberculin preparations not only quantitative, but also qualitative differences are present with respect to the tuberculin effect.

Of our purified preparations only the protein substances have had tuberculin effect, and these preparations with few exceptions have also had antigenic properties in vitro. Two of the important tuberculin preparations, the protein substances precipitable at low pH, and the tuberculin-active substances of the broth, nonprecipitable with acids, gave reaction only with a few of our sera.

The tuberculin effect probably is one of the several manifestations of the specific properties of the antigens.

The Immunological Significance of the Tuberculous Tissue

The introduction of antigens directly into the tuberculous lesions incites more antibody production than the subcutaneous and intravenous treatment of the tuberculous animal. Under appropriate conditions only the injection of the antigens in the tuberculous lesions is effective.

It is very probable that the antibodies are formed in the tuberculous tissue and that the formation of the pathological tissue is the cause of the increased antibody production after tuberculous infection.

Further Observations Concerning the Sensitization of Tuberculous Guinea Pigs

In a former paper (1) we stated that in the study of sensitization of tuberculous guinea pigs we met with the difficulty that the procedure which in the majority of animals gave strong sensitization from August until November 1926, in the following months only rarely gave positive results. With the timothy pollen we were unable to reproduce the strong sensitization which we observed in one guinea pig in November. For awhile we concentrated our efforts on the timothy pollen. After unsuccessful trials with small and large doses injected subcutaneously over long periods we have been led to try to inject the pollen and the tubercle bacillus together, and then to inject the pollen in the tuberculous lesions. One out of three guinea pigs treated in the last mentioned way developed strong sensitiveness.

Local Hypersensitiveness

Treatment of guinea pigs with eggwhite together with small-pox vaccination increases the skinsensitiveness and precipitin content of the serum. The increased response to the treatment seems to be present only if the eggwhite is injected into the vaccinated area.