[Heart transplantation]

The first heart transplantation (SHT) was performed by Professor Ch. Barnard in 1967 but it was not until 1980s that this method became an established approach to treatment of patients with end-stage heart failure. Considering the limited number of donor organs and the number of potential post-transplantation complications, the decision to perform heart transplantation at the right time in an indicated patient is difficult and complex. Subsequent pharmacological management with immunosuppressive agents and other medication becomes everyday life reality. Knowledge of drug interactions and collaboration with cardiologists are necessary in order to maintain long-term treatment success. Despite the current developments in surgical methods, examination methods and immunosuppressant therapy, a range of complications has to be dealt with. The future of care for patients with transplants will rely on the development of new immunosuppressive drugs with a minimum of adverse effects and discovery of a non-invasive technique for graft rejection diagnosis.

In vitro labelling of mouse embryonic stem cells with SPIO nanoparticles

Labelling of mammalian cells with superparamagnetic iron oxide (SPIO) nanoparticles enables to monitor their fate in vivo using magnetic resonance imaging (MRI). However, the question remains whether or not SPIO nanoparticles affect the phenotype of labelled cells. In the present study, the effects of SPIO nanoparticles from two producers on the growth and differentiation of mouse embryonic stem (ES) cells in vitro were investigated. Our observations have shown that SPIO nanoparticles have no effect on the self-renewal of ES cells. Subsequently, we studied the effect of SPIO on the formation of embryoid bodies and neural differentiation of ES cell in monolayer culture. The cavitation of embryoid bodies was partially inhibited and neural differentiation was supported regardless the type of SPIO nanoparticles used. Thus for the first time we documented the effects of SPIO nanoparticles on ES cells and their differentiation.

[Listeriosis - four case reports]

The authors described four cases of listeria infection. The patients were hospitalized in the Department of Infectious Diseases of the Masaryk Hospital in Ustí nad Labem during the epidemic outbreak of this infection around the turn of 2006/2007. The disease in three of the four patients was manifested as purulent meningitis and in the remaining one as a sepsis. All of the patients were above the age of 55 years; moreover, two of them were assumed to be immunocompromised. In three of the patients, whose laboratory findings revealed purulent meningitis, direct microscopy of cerebrospinal fluid (CSF), specific latex agglutination test and PCR were negative. Final diagnosis was determined on the basis of the CSF and blood cultures reported 3-4 days after collection. None of the patients suffered from diarrhoea. In the epidemiological anamnesis, only two of them admitted consumption of food that could become source of infection. The patients were successfully treated with either ampicillin and chloramphenicol.

[Listeriosis a review of current knowledge]

The study includes a recent review of the epidemiology, pathogenesis and clinical picture of listeriosis and new data concerning its treatment.

[Non-pharmacologic therapy of hypertrophic obstructive cardiomyopathy--results of therapy based on percutaneous transluminal septal myocardial ablation compared with results of dual-chamber cardiac pacing]

BACKGROUND

Percutaneous transluminal septal myocardial ablation (PTSMA) and pacemaker (PM) therapy with apical preexcitation are therapeutic options for hypertrophic obstructive cardiomyopathy (HOCM) patients with symptoms despite pharmacological therapy.

AIM

evaluation and comparison of treatment results of PTSMA and PM implantation.

PATIENTS

22 HOCM patients (NYHA class III and IV) with left ventricle outflow tract gradient (LVOTG) at rest more than 30 mm Hg. In group A were evaluated 11 patients treated by PTSMA. Left ventricle outflow tract gradient (LVOTG) was 90.5 +/- 16.0 mm Hg, NYHA class 3.1 +/- 0.2. Group B included 11 patients treated by dual chamber PM implantation, LVOTG in this group was 105 +/- 48 mm Hg, NYHA class 3.0 +/- 0.4.

RESULTS

NYHA class in the group A decreased after treatment to 1.8 +/- 0.6 (p < 0.01), LVOTG to 24 +/- 12 mm Hg (p < 0.001). There was observed significant decrease in grade of systolic anterior motion (SAM), interventricular septum (IVS) thickness and left atrium (LA) size. Left ventricle end systolic diameter (LV SD) and left ventricle end diastolic diameter (LV DD) increased during follow-up. Decrease of NYHA class in the group B was to 2.1 +/- 0.6 (p < 0.001), LVOTG to 25.5 +/- 21.0 mm Hg (p < 0.001). Changes of other parameters in the group B were not significant, except decrease of SAM. Comparison of both groups: NYHA class change PTSMA/PM: 1.3 +/- 0.6/0.9 +/- 0.4 (p < 0.05), LVOTG change PTSMA/PM: -66 +/- 20/-79 +/- 46 mm Hg (p = n.s.). LV SD assessment comparison of LV SD change PTSMA/PM: 5 +/- 5/1 +/- 5 mm (p < 0.05). LA assessment - comparison of LA change PTSMA/PM: 5 +/- 5/-1 +/- 4 mm (p < 0.05). Other changes were not significant.

CONCLUSION

Both therapeutic approaches - PTSMA and PM implantation - resulted in significant improvement of functional capacity assessed by NYHA classification. Decrease of LVOTG was also significant and was similar in both groups, NYHA class improvement as well as LA size decrease and LV DS increase were more expressed in PTSMA group.

Liposomal preparations of muramyl glycopeptides as immunomodulators and adjuvants

The need for safe and structurally defined immunomodulators and adjuvants is increasing in connection with the recently observed marked increase in the prevalence of pathological conditions characterized by immunodeficiency. Important groups of such compounds are muramyl glycopeptides, analogs of muramyl dipeptide (MDP), glucosaminyl-muramyl dipeptide (GMDP), and desmuramylpeptides. We have designed and synthesized new types of analogs with changes in both the sugar and the peptide parts of the molecule that show a high immunostimulating and adjuvant activity and suppressed adverse side effects. The introduction of lipophilic residues has also improved their incorporation into liposomes, which represent a suitable drug carrier. The proliposome-liposome method is based on the conversion of the initial proliposome preparation into liposome dispersion by dilution with the aqueous phase. The description of a home-made stirred thermostated cell and its link-up with a liquid delivery system for a rapid and automated preparation of multilamellar liposomes at strictly controlled conditions (sterility, temperature, dilution rate and schedule) is presented. The cell has been designed for laboratory-scale preparation of liposomes (300-1000 mg of phospholipid per run) in a procedure taking less than 90 min. The method can be readily scaled up. Examples of adjuvant and immunostimulatory effect of liposomal preparation in mice model will be presented.

[Does G8002A polymorphism in endothelin gene have a meaning for other risks at the patients with heart failure?]

Objective of the work is to determine the relation of G8002 polymorhism in endothelin 1 gene to the incidence of diabetes mellitus (DM), ischemic disease of lower limbs (ID LL) and myocardial infarction (MI) at the patients with heart failure. METHODICS: There were observed 224 patients, 176 males, 48 females, average age 55 +/- 12 years, NYHA II/III/IV 82/131/11, average EF LK 25 +/- 7 %, diagnosis ischemic heart disease (IHD) 133, dilatation cardiomyopathy (DCMP) 91.

RESULTS

Patients with IHD had higher incidence of hypertension (p < 0.0007), diabetes mellitus (p < 0.00007) and hyperlipoproteinemy (p < 0.0006) than patients with DCMP. Patients with IHD who experienced MI had a difference in the distribution of G8002A genotypes for endothelin 1 gene: G 0.718 and A 0.282 alleles vs ischemic patients without MI G 0.882 and A 0.118 (p < 0.05) alleles. Ischemic patients with DM had G allele in 0.67 and A 0.33 unlike ischemic patients without DM G allele 0.791 and A 0.209 (p < 0.03). Ischemic patients with synchronous ID LL had G allele in 0.718 and A 0.282 vs ischemic patients without ID LL G allele 0.882 and A 0.118 (p < 0.0004). At the patients with DCMP there was not found a difference in G8002A genotype and the presence of DM or ID LL.

RESULTS

At the patients with heart failure on the basis of ischemic heart disease there was found a difference in endothelin G8002A genotype distribution depending on other accessory diseases. There was more frequently present an A allele and less present G allele in the ischemic patients with DM, who had experienced MI or ID LL than in the ischemic patients without these diseases. Genotype with A allele is connected with higher risk of all accessory diseases.

Prognostic Importance of the Right Ventricular Function Assessed by Doppler Tissue Imaging

AIMS

We sought to assess whether the peak systolic and diastolic tricuspid annular velocities as indicators of the right ventricular systolic and diastolic function are of prognostic importance in patients with symptomatic heart failure.

METHODS AND RESULTS

The study included 139 consecutive patients with symptomatic heart failure. Their mean left ventricular ejection fraction was 24% (range, 10-39%); 107 patients (77%) were in functional class III according to the New York Heart Association. All patients underwent clinical and laboratory examination, standard echocardiography completed by the Doppler tissue imaging of the tricuspid annular motion, and the right-sided heart catheterization. They were followed up for cardiac-related death and non-fatal cardiac events including the need for implantation of a cardioverter-defibrillator and hospitalization for heart failure. The median follow-up was 11 months (range, 1-48 months). There were 17 cardiac-related deaths and 23 non-fatal cardiac events. The multivariate stepwise Cox regression modelling revealed three effective predictors for both survival and event-free survival: aetiology of heart failure, left ventricular end-diastolic diameter, and the peak systolic tricuspid annular velocity (Sa). Patients with Sa<10.8cms(-1) exhibited worse survival (P=0.048) and event-free survival (P<0.001) compared with those having Sa>/=10.8cms(-1). Risk values of Sa (<10.8cms(-1)) and the left ventricular end-diastolic diameter (>70mm) were found to be of additive simultaneous influence leading to a very poor prognosis, mainly if aetiology of heart failure was idiopathic dilated cardiomyopathy (P<0.001).

CONCLUSION

The Sa represents a significant independent predictor of survival and event-free survival in patients with symptomatic heart failure. Its combination with the left ventricular end-diastolic diameter provides a very powerful tool for patient risk stratification.

Pulsed Doppler tissue imaging of the velocity of tricuspid annular systolic motion; a new, rapid, and non-invasive method of evaluating right ventricular systolic function

AIMS

Rapid, accurate, and widely available non-invasive evaluation of right ventricular function still presents a problem. The purpose of the study was to determine whether the parameters derived from Doppler tissue imaging of tricuspid annular motion could be used as indexes of right ventricular function in patients with heart failure.

METHODS

Standard and pulsed Doppler tissue echocardiography were obtained in 44 patients with heart failure (mean left ventricular ejection fraction 24 +/- 7%) and in 30 age- and sex-matched healthy volunteers. The tricuspid annular systolic and diastolic velocities were acquired in apical four-chamber views at the junction of the right ventricular free wall and the anterior leaflet of the tricuspid valve using Doppler tissue imaging. Within 2 h of Doppler tissue imaging, the first-pass radionuclide ventriculogram, determining right ventricular ejection fraction and equilibrium gated radionuclide ventriculography single photon emission computed tomography, were performed in all patients.

RESULTS

In patients with heart failure, the peak systolic annular velocity was significantly lower and the time from the onset of the electrocardiographic QRS complex to the peak of systolic annular velocity was significantly greater than the corresponding values in healthy subjects (10.3 +/- 2.6 cm. s(-1) vs 15.5 +/- 2.6 cm.s(-1), P < 0.001, and 198 +/- 34ms vs 171 +/- 29 ms, P < 0.01, respectively). There was a good correlation between systolic annular velocity and right ventricular ejection fraction (r = 0.648, P <0.001). A systolic annular velocity < 11.5 cm.s(-1)predicted right ventricular dysfunction (ejection fraction < 45%) with a sensitivity of 90% and a specificity of 85%.

CONCLUSION

We conclude that the evaluation of peak systolic tricuspid annular velocity using Doppler tissue imaging provides a simple, rapid, and non-invasive tool for assessing right ventricular systolic function in patients with heart failure.

[Transplantation of the heart--indications, complications, therapy--our experience from investigations of 100 patients after cardiac transplantation]

Transplantation of the heart has become an accepted method for the treatment of terminal cardiac failure. Despite obvious advances in the care of patients after trasplantation a number of problems exist. The authors summarize their experience with the long-term follow-up of 100 adult patients with transplantations made in the Brno Centre of Cardiovascular and Transplantation Surgery. One-year survival in the group of patients is 80%, three-year survival 69%. The authors discuss indications and contraindications of cardiac transplantations, necessary preoperative and postoperative examinations, they follow-up the most serious complications during the posttransplantation period. They mention therapeutic possibilities and outline briefly the perspectives of care of patients after cardiac transplantation. Despite the number of problems encountered transplantation of the heart is for indicated patients with cardiac failure a unique chance to improve the prognosis of survival and the quality of life.

Characterization of a sapphire-epoxy coating for capillary electrophoresis

A new procedure for coating capillaries for capillary electrophoresis applying a sapphire (alumina) containing epoxy resin was developed. Coated capillaries showed considerably reduced electroosmotic flow, and decreased the adsorption of proteins to the internal wall of the capillary. Coating is transparent down to 195 nm and can be used with advantage to analyze different kinds of substances, such as small cations and/or anions, and proteins.

Secondary immunodeficiency in dogs with enteric, dermatologic, infectious or parasitic diseases

A group of 238 dogs with various infectious and parasitic disease, in which suppressed activity of the immune system could e presumed, was examined using a set of immunological methods. The frequency and depth of immunosuppression and its association with certain infectious or parasitic disease were determined. Marked immunosuppression was found 62 (26%) of the dogs examined. Dogs with distemper, parvovirosis and German Shepherd dog pyoderma (GSP) were the most severely impaired. Dogs in acute phases of distemper or parvovirosis had decreased numbers and activity of lymphocytes and decreased immunoglobulin levels. Dogs with GSP had some of the following immunologic symptoms: inhibition of phagocytosis, reduced activity of lymphocytes, decreased levels of haemolytic complement and increased levels of immunoglobulin and lysozyme. A persistent immunosuppression was found in 12 dogs. These dogs were diagnosed with deep pyoderma, giardiasis, dermatophytosis or neoplasms. Although samples were not taken before the clinical diseases appeared, it can be presumed that some diseases caused immunosuppression (distemper or parvovirosis), and for other diseases immunosuppression was a predisposing factor (dermatophytosis, giardiasis and possibly GSP).

Immunosuppression in dogs with pyoderma and/or demodicosis

The occurrence of decreased activity of the immune system was studied in a group of 66 dogs with various combinations of pyoderma and demodicosis. Our complex examination of the dogs included the following: leukocyte count, differential count, phagocytosis, blastogenic lymphocyte transformation and quantitation of total serum immunoglobulins, lysozyme and haemolytic complement. Immunosuppression was found in 19 (28.8%) cases. Immunosuppression was rare in dogs with demodicosis and did not appear without a concurrent pyoderma. An increase in the neutrophil counts and total serum immunoglobulin levels significant was found in dogs with demodicosis combined with pyoderma. On the contrary, marked immunosuppression was detected in dogs with deep pyoderma. A considerable immunosuppression was present in 7 of 10 German shepherds dog pyoderma (GSP). Significant depressions were found in phagocyte activity and lymphocyte activity. Immunosuppression was observed in 4 of 9 dogs in other breeds with uncomplicated deep pyoderma. All groups of dogs with pyoderma showed a significant increase in total serum immunoglobulins. Conclusion from these findings is that deep pyoderma more than Demodicosis was concerned with immunosuppression. German shepherds with deep pyoderma had more expressed immunosuppression than other breeds.

Development of a disease control programme based on the use of an inactivated vaccine against infectious bovine rhinotracheitis

Studies to investigate the efficacy of an inactivated vaccine against infectious bovine rhinotracheitis (IBR) suggest that this vaccine can prevent the in utero infection of calves from experimentally infected dams. In an experimental herd the inactivated vaccine induced a humoral immune response in both seropositive and seronegative cattle and, after subsequent intratracheal infection with IBR (BHV-1) virus, prevented development of symptoms in the cows and protected their fetuses against infection. The calves were all healthy and were born at term. The non-vaccinated, seronegative cows responded to the experimental infection with mild respiratory disease and abortion of 4 out of 10 fetuses. All organs from the aborted fetuses were found to have IBR virus. Through the use of this vaccine, the nucleus of a seronegative, virus-free breeding herd can be established. Thus, valuable genetic material can be preserved and the eradication of IBR becomes a realistic prospect. From our initially strictly controlled experiments producing 234 healthy calves, our programme was expanded into farm practice where 1001 calves were reared free from IBR virus.

The efficacy of an inactivated IBR vaccine in the prevention of intra-uterine infection and its use in a disease-control programme

The effects of administration of an established, inactivated IBR vaccine were studied in 30 cows from two herds (one seropositive and one seronegative). All acquired immunity which, after subsequent intratracheal infection with IBR virus, prevented development of symptoms in the cows and protected their foetuses against viral infection in utero. The calves were all healthy and were born at normal term. Ten non-vaccinated cows from the seronegative herd responded to the experimental infection with mild respiratory disease and abortion of four out of 10 foetuses. Organs from the aborted foetuses were found to have IBR virus. In a breeding herd, without clinical signs of disease but with 40% of cows tested as seropositive, a 2-year disease-control programme was initiated. A total of 234 newborn calves were examined and it was shown that immunization of their dams with an inactivated vaccine conferred full in utero protection against IBR-virus infection. When such calves are reared in isolation they can be used as the nucleus for a seronegative breeding herd.

[Causes of anaphylactoid reactions in cattle after administration of lipoid preparations]

In 1986-1988, adverse anaphylactoid reactions (AR) were observed in animals in Czechoslovakia after the administration of oil adjuvant-containing vaccines or other lipoid drugs. Treated animals showed signs resembling the classic anaphylactic reaction, i.e. restlessness, salivation, pruritus, oedema and cyanosis of udder and vulva, and eyelid oedema, developing within a few minutes. The reactions were not elicited by the antigen alone, but by the oil adjuvant. The aim of our experiments was to identify substances eliciting the reaction in susceptible animals and to investigate possible induction mechanisms. The emulsifier Tween 80 has been demonstrated to be an AR inducing component of vaccines and drugs (Tab. I and III). Weak or moderate reactions were observed in 33% of animals treated with 5% Tween and 66% of those treated with 10% Tween showed strong reactions. On the other hand, no reactions were elicited by treatment with several paraffin oils of different quality (Tab. I) nor with an oil-in-water emulsion containing Montanid as an emulsifier (Tab. II). The role of the vegetative nervous system in the rise of AR has been confirmed. AR were suppressed in animals pretreated with parasympatholytic atropine and enhanced in a part of those pretreated with parasympathomimetic pilocarpine (Tab. III). The percentage of animals affected and the intensity of AR were also lower in animals pretreated with complement inhibitor epsilon-aminocapronic acid (Tab. IV). A major role of complement activation is suggested in the discussion of possible mechanisms of AR induction. It is possible to draw a conclusion on the basis of the results presented here and of the analysis of individual cases that a certain degree of animal susceptibility, depending on the phase of reproductive cycle, metabolism level and neurovegetative balance is necessary besides the administration of an AR inducer (Tween 80 in our case). Hence it seems that the adverse anaphylactoid reactions results from interactions of the two factors, i.e. administration of an AR inducer to susceptible animals.

Amperometric glucose biosensor with extended concentration range utilizing complexation effect of borate

Borate buffer strongly decreases amperometric response of a glucose oxidase linked pO2 or H2O2 sensing electrode, extending substantially its linear calibration range. With increasing pH and concentration of the buffer the upper limit for glucose can be varied between 1 and 30 mmol l-1 glucose. The effect of borate ion is explained by the rapid complexation of glucose decreasing the equilibrium concentration of free beta-anomer, the specific substrate of glucose oxidase. The high loading of cross-linked enzyme inside the sensor membrane is necessary for the measurement to ensure an almost constant response factor (delta i per 1 mmol l-1) between pH 5 and 10. Analysis in stirred solution and in a flow-through system has been employed for the measurement of elevated glucose levels in heparinized human blood or plasma samples.

[Nonspecific immunostimulating activity of Bordetella bronchiseptica bacterin in tests on mice and calves]

Three experimental models were used to verify the effectiveness of immunostimulant preparations of microbial origin. Of the four microbial species, used in the tests with the stimulation of mice against subsequent infection with the virulent strain of Pasteurella multocida, the highest resistance-increasing power was recorded in Bordetella bronchiseptica. There were large differences in stimulation activity between its strains, ranging from those with a low activity up to strain 6229, which increased the LD50 of the infected mice to a level 72 times as high as in the control. The differences in the survival of the mice also varied within the range between immunostimulation and infection, the best effect being obtained when the mice were stimulated 48 h before the infection. No significant difference was recorded between the use of the bacterin of B. bronchiseptica alone or B. bronchiseptica bacterine with oil adjuvant. The immunostimulant activity of B. bronchiseptica was also demonstrated in the model of sublethally irradiated mice in which the preventive administration 24 h before irradiation led to earlier and faster regeneration of the lymphoid tissue: this led to a higher weight of the spleen, to an increase in the number of peripheral leucocytes, and increased activity of chemiluminiscence six days after irradiation. The bacterine of B. bronchiseptica was also used at different concentrations and in combinations with other substances to stimulate two-month-old clinically healthy calves. The most pronounced effect was obtained after the administration of B. bronciseptica bacterine with oil adjuvant and after administration of the same substances together with vitamin A: twenty-four hours after these treatments there was an increased number of peripheral leucocytes and after 2-4 days an increased activity was observed in the MSHP particle phagocytosis test and in the chemiluminiscence test. The activity of lymphocytes in the blastic transformation test was insignificantly increased seven days after stimulation.

The possibilities of predicting allergic effects of new antirheumatics

The new antirheumatic drugs Benzofenac and Flobufen were assessed for their possible influence on various immunological parameters. They were shown to enhance passive cutaneous anaphylaxis (PCA) to ovalbumin in rats and to suppress the numbers of helper and suppressor T-lymphocytes in mice. The effect of Benzofenac in the latter system was found to be more pronounced. The drugs had no effects in any of the other test systems, including the development of delayed hypersensitivity, mitogen-induced lymphocyte proliferation in vitro and the production of antisera (as tested by PCA).

Nonspecific inhibitor of DNA synthesis elaborated by T-acceptor cells. II. Requirements for its production and action

The production of a nonspecific inhibitor of DNA synthesis (nsINH) appears to be one of the final events in the T-suppressor cell circuit in mice exposed to contact sensitizers. We report here that: The nsINH suppresses the proliferative response to a polyclonal T-cell mitogen, concanavalin A (Con A), regardless of the dose of Con A used. It also suppresses DNA synthesis in lymphoid cells stimulated with alloantigens. This suppression can be completely eliminated by adding exogenous interleukin 2 (IL-2). DNA synthesis in lymphoid cells exposed to nsINH before the proliferative stimulus is uninfluenced so that activation of the lymphoid cells at the same time as exposure to nsINH seems to be a requirement for its action. Since the activity of nsINH can be absorbed by activated Lyt-1+ or Lyt-2+ lymphocytes, the early activated T cell appears to be a target of the action of nsINH. The production of nsINH is abolished or severely reduced by adult thymectomy. Natural killer (NK) cells are resistant to nsINH action and no interferon (IFN)-like activity can be demonstrated in nsINH preparation using a conventional assay for IFN.

[Analysis of factors affecting the electric conductivity of cow's milk--breed, locale, season]

The problem was studied in a set of 678 mammary glands of 212 cows - crossbreds between the Holstein-Friesian breed with the Slovak Spotted cattle, crossbreds of the Black-Pied Lowland and Bohemian Spotted breed, and three-way crossbreds of the Black-Pied Lowland, Swedish White and Bohemian Spotted cattle. The confrontation of the confidence intervals of milk conductivity (MC) in healthy mammary glands at alpha = 0.05 showed that in the crossbreds of the Black-Pied Lowland cattle the MC was statistically significantly higher than in the breed types of the Holstein-Friesian cattle. The MC values decrease when there is a larger proportion of the blood of beef-and-dairy cattle (Slovak Spotted and Bohemian Spotted breeds). The locality where the stock was kept was found to act as an important factor underlying MC only in cases when both the geographical conditions and breed proportions were different. In a set homogenized with respect to the breeds, statistically significant differences in MC were demonstrated between the spring and summer season, spring and autumn, summer and autumn, and autumn and winter season.

Cytotoxicity of normal rabbit serum for chicken lymphoid cells. I. Localization of the activity

Normal rabbit sera were found to be highly cytotoxic for chicken thymus cells. When the sera were fractionated on Sephadex G-200, the natural cytotoixc activity resided exclusively in the first peak. It was found to be complement-dependent and heat stable at 56 degrees. On the other hand, in the serum of immunized animals the specific cytotoxic activity appeared in the second peak.

Further characterization of antigen-dependent migration inhibition factor in mice

Antigen-dependent MIF was produced in inbred mice. Lymph node cells from mice sensitized to tubercle bacilli were incubated with small quantities of antigen. The supernatant contained antigen-dependent MIF and its activity when tested on mouse and rabbit spleen was minimal unless PPD was added to the supernatant. The production of the antigen-dependent MIF was T cell-dependent, as shown by the use of anti-theta serum. Its molecular weight was in the range of 50--100,000 and it was concluded that the factor is different from conventional antibodies or antigen-antibody complexes.

The effect of lymphokines on the development of delayed hypersensitivity to an unrelated antigen

The development of delayed hypersensitivity to sheep red cells in rabbits was assessed by measuring the inhibition of migration of cells from spleen fragments in the presence of sheep red cell antigen. Supernatants containing migration inhibition factor were prepared by incubating lymph node cells from rabbits immunized with Freund's complete adjuvant with PPD. Sheep red cells injected together with these supernatants intravenously gave rise to delayed hypersensitivity. In contrast the injection of sheep red cells alone or with control supernatants did not give rise to delayed hypersensitivity.

Demonstration of the inflammatory activity of the supernatant of hypersensitive lymph node cells incubated with a high dose of antigen

When lymphocytes from hypersensitive animals are incubated with antigen, biologically active substances are formed which inhibit the migration of mesenchymal cells from normal animals.

These substances were tested by intradermal injection in guinea-pigs and rabbits. The supernatants from incubation of lymphocytes with a high dose of antigen caused immediate pallor which lasted several hours. Later there was a macroscopic inflammation maximal at 24 hours. The histology was characteristic of a delayed hypersensitivity reaction.

The injection of the supernatant from hypersensitive lymphocytes incubated with a small dose of antigen caused little or no pallor and was not followed by a delayed inflammatory reaction. Injection of this supernatant together with the antigen did not potentiate or alter the reaction, in contrast to in vitro experiments where the inhibition of the migration by this supernatant was potentiated by antigen.

Besides this factor a distinct factor occurs in extracts and supernatant fluids of lymphocytes cultivated without antigen and those from control animals, which increases vascular permeability. This substance is probably identical with the lymph node permeability factor (LNPF). The possible role of these biologically active substances in the mechanism of delayed type hypersensitivity is discussed.