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It is undeniably one of the greatest findings in biology that (with some very minor exceptions) every cell in the body possesses the whole genetic information needed to generate a complete individual. Today, this concept has been so thoroughly assimilated that we struggle to still see how surprising this finding actually was: all cellular phenotypes naturally occurring in one person are generated from genetic uniformity, and thus are per definition epigenetic. Transcriptional mechanisms are clearly critical for developing and protecting cell identities, because a mis-expression of few or even single genes can efficiently induce inappropriate cellular programmes. However, how transcriptional activities are molecularly controlled and which of the many known epigenomic features have causal roles remains unclear. Today, clarification of this issue is more pressing than ever because profiling efforts and epigenome-wide association studies (EWAS) continuously provide comprehensive datasets depicting epigenomic differences between tissues and disease states. In this commentary, we propagate the idea of a widespread follow-up use of epigenome editing technology in EWAS studies. This would enable them to address the questions of which features, where in the genome, and which circumstances are essential to shape development and trigger disease states.

Knowledge of tetanus immunity in equine patients is crucial in cases of injuries, elective surgeries, or when effective vaccination protocols are to be designed. The Fassisi® TetaCheck is a stall-side rapid test which was developed to address these issues. The purpose of the present study was to evaluate its performance parameters. To this end, the qualitative test results obtained by two blinded observers were compared to tetanus toxoid antibody levels from 99 serum samples, measured with a double antigen ELISA. Additionally the colour intensities of the test window were quantified using a camera and photo editing software. Assuming that the protective level of tetanus toxoid antibodies is ≥ 0.1 IE/ml, the tetanus quick stick (TQS) showed a sensitivity of 83.6% and a specificity of 100%. almost perfect (K = 0.88). Exchanging the observer did not affect the interpretation of theTQS (K = 0.80; K = 0.84). The definition of five distinct colour intensities of the "test window" enabled a clear differentiation of unprotected individuals from those with a protective immunity. There was a linear relationship between the objectively measured colour intensities and the tetanus toxoid antibody concentration (r2 = 0.74). The TQS thus proved to be a robust and reliable test in the stall-side assessment of tetanus immunity in horses. Its implementation in equine daily practice can help to avoid unnecessary immunizations in adult horses and therefore minimize vaccination side effects.

It is generally recommended to vaccinate elderly people against tetanus. Is this really essential?The levels of antibodies to tetanus toxin in serum of 2936 individuals of various age groups were determined by means of an ELISA.Obviously, the antibody titers definitely diminish in the old individuals. About 50 % of people80 years possess antibody titers0.5 IU/ml and about 30 % antibody titers0.1 IU/ml, which means that they are not absolutely protected against tetanus.This, however is not due to a general decline of antibodies, since levels of immunoglobulins of the classes IgG, IgM and especially of IgA are higher with growing age.It can be assumed that the awareness for the necessity for vaccination is lacking.

A 80 year-old woman contracted an abrasion of her right forearm while gardening. 5 days later, dysphagia, trismus and a cramp of the right hand developed. On admission (8 days after the injury) cramps of the platysma and pharyngeal muscles were observed. A tetanus vaccination had not been carried out for years.Electrophysiologically a pathological masseter inhibitory reflex with a missing "silent period" was observed. The level of serum anti-tetanus-toxoid IgG antibodies was 0.03 IU/ml (definitively protective above 0.1 IU/ml). Free tetanus toxin was not detectable in the serum upon mouse challenge. The diagnosis of tetanus was made based on the typical symptoms and the serological susceptibility.On admission the wound was antiseptically cleaned and a bandage was applied. On the next day a debridement was performed. After taking a serum sample the patient was immunized against tetanus (active and passive). On the following two days the patient received a further dose of tetanus-antitoxin. The patient was treated with metronidazole for 8 and with penicillin G for 10 days. Within the first days after hospital admission laryngospasms, tachycardia and tachypnoe occurred. From the 7 (th) day in hospital the trismus and the cramp of the hand improved. 4 weeks after admission the patient was discharged; the trismus had completely disappeared, but a slight cramp of the hand was still present.Minor superficial injuries can lead to acute tetanus, if the level of anti-tetanus toxin-antibodies is non-protective and a disinfective wound cleaning and a postexpositional vaccination are not performed.

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Signal transfer between neurons and between neurons and muscle cells is mediated by the secretion of neurotransmitters. The axon of the presynaptic cell contains synaptic vesicles, the storage organelles for neurotransmitters. Arrival of an action potential causes calcium-influx into the axon and leads to fusion of synaptic vesicles with the presynaptic plasma membrane. Recently, the events between calcium-influx and membrane fusion were elucidated on a molecular level. The family of SNARE-proteins was identified as the key players in neurosecretion. They are located on synaptic vesicles (VAMP) or on the presynaptic plasma membrane (syntaxin, SNAP-25). Intimate protein-protein interactions between the SNARE-proteins are responsible for the attachment and merger of vesicle and the plasma membrane. Fusion is triggered by calcium-binding to synaptotagmin, another protein recently identified on synaptic vesicles. The molecular mechanism of the action of clostridial neurotoxins was also elucidated. Botulinum-as well as Tetanus toxins are proteases which cleave neuronal SNARE-proteins. This explains the long known inhibition of neurosecretion caused by these toxins. The proteolytic action of Tetanus- and Botulinum toxin occurs in different types of neurons, resulting in a stimulatory or inhibitory effect on muscle cells. This selective degradation of SNAREs explains the opposing clinical signs of tetanus (cramps) and botulismus (paralysis).

A tetanus split vaccine consisting of the purified C fragment of tetanus toxin was compared with normal adsorbed toxoid vaccine with respect to local reactions and immunogenicity. Altogether, 200 volunteers with primary vaccination against tetanus were vaccinated. Local reactions were studied in 170 persons, the immune response in 87. Immunogenicity, expressed as mean conversion factor, was identical for both groups. Local reactions, including frequency, duration and intensity of symptoms, were reduced by 60% in the subjects given split vaccine. In both groups a positive correlation between preimmunization antibody titer and the mean extent of the local reaction was observed.

Great progress was achieved in the clarification of the molecular structure and the mechanism of action of the toxins of pathogenic forms of bacteria. Proportions of toxins of Corynebacterium diphtheriae and of Pseudomonas aeruginosa transfer from the NAD and ADP-ribose protein to an amino acid of the elongation factor 2. Thus the protein synthesis is much inhibited. The cholera toxin and the L-toxin from Escherichia coli have a similar structure. They transfer an ADP-ribose portion from NAD to the GTP-protein of the adenylate cyclase complex, by which means the GTPase activity is reduced. The increase of the cAMP content leads to an increase of the permeability of the cells of the intestinal epithelium. The tetanospasmin decreases the production of the inhibitingly acting neurotransmitters ( glycin ) from intermediate neurons and thus evokes spasms. The botulinum toxin inhibits the release of acetylcholine from the motor end-plates and leads to paralyses. Staphylococcus aureus and Clostridium perfringens form among others cytolysins which are injurious to membranes.

Nerve cells with their very long axons and dendrites have an effective system of anterograde and retrograde transport. In the retrograde direction there is, in addition to endogeneous cell constituents, a substantial transport of exogenous material like e.g. trophic factors like NGF. We have found that molecules which bind with high affinity to receptors in the nerve teminal surface membranes (e.g. NGF, tetanus and cholera toxin, lectins) are selectively internalized and transported retrogrdely to the cell body. Although most of them are incorporated into lysosomes in the cell body, they can nevertheless exert specific signal functions in the cell (NGF). Tetanus toxin, however, is released by the dendrites and transferred trans-synaptically to higher order neurons. We suggest that this retrograde and trans-synaptic transport represents an important pathway for "trophic" signal molekules, which convey information from the target cells to the innervating neurons. The same pathways can be used by neurotoxins *tetanus toxin) and neurotrophic viruses for entering the nervous system.

Tetanus is subdivided into 3 degrees of severity according to the course. When death occurs, we differentiate those cases due to the disease itself (16) and those resulting from late complications or avoidable technical defects (12). 82 of our 111 patients-79 men and women-had been neither passively nor actively immunized and none of the supposedly actively immunized had been inoculated properly. The horse serum available in earlier years was considered unsuitable while an intravenous human serum recently produced by Messrs Immuno of Vienna justified greater expectations. Sedation or prolonged sleep with and without relaxation, tube feeding and parenteral feeding, prolonged intubation or trachectomy, duration of the life-threatening phase of the disease, breaking off treatment ("stealing out"), mobilization and finally, the question of expense, bear no relation to the extremely small cost of a confirmed triple inoculation. An urgent consequence of this is obligatory active immunization in early childhood if an earlier inoculation has not been done, but also at any time afterwards.

By means of semipurified tetanus toxin for solid phase coating in an enzyme immunoassay (ELISA) for detection of specific IgG and IgM antibodies a detection limit of 0.02 IU per litre was achieved. The addition of serum from animals like horses or goats as inert protein to the dilution medium was omitted to prevent a displacement of human antibodies by antitetanus antibodies present in the animals sera. The specificity of the ELISA was demonstrated by inhibition experiments with soluble antigen and in an ELISA for detection of anti-tetanus toxin antibodies from mice immunized with the toxoid from the different purification steps.

The effect of heterologous and homologous antitoxin is the same if an equal amount of antitoxin is present in the organism. In man there are no circulating antibodies in the blood after the first injection of the toxoid because there is no natural immunity against the tetanus antigen. After the second injection, man develops the same immunity as animals. Large antitoxin doses protect people for a longer period than small doses. Normally 3,000 I. U. of the heterologous antitoxin protects people for 2 to 3 weeks. In man and sheep 2 ml of the adsorbed vaccine produces an earlier and longer-lasting immunity than 0.5 ml. Simultaneous active and passive prophylaxis is superior to passive prophylaxis alone. To achieve a long-lasting active immunity, 2 ml of the vaccine should first be injected and a booster dose 7 to 10 days later, and again 6 to 12 weeks after the first dose. Immediate vaccination against tetanus following an injury will not protect a person who has not been vaccinated previously, as the active immunity will start too late.

The aim of this work was to optimize the antigen-specific prestimulation of human lymphocytes for further hybridization to produce human monoclonal antibodies. In vitro stimulation of human peripheral blood lymphocytes with purified Tetanus Toxoid (TT) resulted both in an increased amount of secreted specific antibodies and in an enhancement of the portion of anti-TT antibodies in the level of total immunoglobulin secretion. Both IgG and IgM antibodies were found. Donors who had not been boostered in vivo with TT for more than 10 years also showed an antibody response to the antigen in vitro. Five days after in vivo boostering we found in lymphocyte cultures derived from 3 donors an enhanced antibody synthesis in the response to TT and also an increased portion of specific antibodies in the spontaneously secreted immunoglobulin in unstimulated control cultures.

After injection of known numbers of viable tumour cells admixed with tetanus spores into the subcutaneous tissue between the shoulder blades the sigmoidal tetanus lethality curves of mice can be quantitatively analysed following the underlying growth of tetanus clostridia and tumour cells. We suggest that the "driving force" for exponential clostridial growth and toxin synthesis are oxygen-consuming clones of tumour cells. Our experimental data are in good accordance with a stochastic mathematical model which allows for computing the cloning probability of one single spore on the basis of a 1-mitosis-1-clostridium division-principle.

Various lots of intravenous immunoglobulins for passive immunization should contain almost the same, broad, antibody profile and provoke very low frequencies of untoward reactions. From 1976-1982 a study was undertaken to measure the level of antibodies directed against tetanustoxin, diphtheriatoxin, streptolysin O, staphylolysin, and salmonella in up to 82 lots. It is interesting to note that the measured level of antibodies in intravenous immunoglobulins varied only slightly as well qualitatively as quantitatively with one exception: an immunoglobulin of placental origin. The amount of tetanusantitoxin in the majority of lots of that preparation was ten-fold lower than that of the other immunoglobulins. Intravenous immunoglobulins contain generally 3-6 IE/ml antistaphylolysin, 600-1200 IE/ml antistreptolysin O, 10-20 IE/ml tetanusantitoxin, and 1-2 IE/ml diphtheriaantitoxin. Antibodies to salmonella could not be demonstrated. Some of the lots exhibited isoagglutinins up to a dilution of 1 : 4.

It could be ascertained that the quantitative and qualitative identification of bacterial antigens and antibodies can be improved and completed, respectively, by DCIE in selected indications given. The diffusion counter immunoelectrophoresis has several advantages (easy handling, saving of time, easy evaluability). Our own tests confirmed the possibility of developing DCIE as a screening method to identify diphtheria and tetanus antibodies.