Doses Of Tetanus Toxin Research Articles

Non-invasive, epicutaneous immunisation with toxoid in deformable vesicles protects mice against tetanus, chiefly owing to a Th2 response

A non-invasive, intra/transcutaneous immunisation of mice with a suitable combination of tetanus toxoid, ultradeformable vesicle (Transfersome®) carrier, and monophosphoryl lipid A adjuvant targets immuno-competent cells in a body and can protect 100% of the tested mice against an otherwise lethal (50×LD50) parenteral tetanus toxin challenge. The late immune response to the epicutaneously applied tetanus toxoid in such vesicles consists chiefly of circulating IgG1 and IgG2b antibody isotypes, indicative of a specific Th2 cellular response bias. Immunisations by subcutaneous injections moreover protect 100% of mice against a similar, otherwise lethal, dose of tetanus toxin. However, the immune response to transcutaneous and invasive immunisation differs. The latter elicits mainly IgG1 and IgG2b as well as IgG2a antibody isotypes, indicative of a mixed Th1/Th2 response. The cytokine response of the intra/transcutaneously and subcutaneously immunised mice reflects the difference in the organ-specific manner. IFN-γ concentration is appreciably increased in the draining lymph nodes and IL-10 in spleen. Since tetanus is a neutral antigen, both the Th1-specific IFN-γ and the Th-2 specific-IL-10 are observable.

Synaptic inhibition in primary and secondary chronic epileptic foci induced by intrahippocampal tetanus toxin in the rat.

1. Injecting twelve mouse minimum lethal doses of tetanus toxin into one hippocampus of a rat leads to the development of chronic epileptic foci in both hippocampi. These generate intermittent epileptic discharges for 6-8 weeks. Here we compare GABAergic inhibition, 10-18 days after injection, in slices prepared from the injected and contralateral hippocampi (respectively the primary and the secondary or 'mirror' foci), using both neurochemical and electrophysiological methods. 2. Epileptic activity was recorded from slices of both hippocampi from all tetanus toxin-injected rats. Evoked epileptic discharges were similar on the two sides, but spontaneous epileptic discharges were more common contralaterally. 3. Ca(2+)-dependent, K(+)-stimulated (synaptic) release of radiolabelled GABA was depressed in slices from the injected hippocampus, compared with vehicle-injected controls. In contrast, slices from the contralateral hippocampus had normal levels of Ca(2+)-dependent, K(+)-stimulated GABA release, even though adjacent slices were epileptogenic. 4. Intracellular recordings revealed that both fast and slow stimulus-evoked inhibitory postsynaptic potentials (IPSPs) were abolished in CA3 pyramidal cells in the primary focus. In the secondary focus, however, fast IPSPs were seen in seven of twenty-five cells, and slow IPSPs were seen in all cells if the stimulus was strong enough. 5. Monosynaptic IPSPs were isolated pharmacologically by blocking glutamatergic excitatory postsynaptic potentials (EPSPs) with 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and D(-)-2-amino-5-phosphopentanoic acid (AP-5). No monosynaptic IPSPs were uncovered in cells from the primary focus at any stimulus strength. Monosynaptic IPSPs were evoked in all cells from both the secondary focus and control slices. The estimated conductances of monosynaptic fast IPSPs were similar in cells from the secondary focus and from the controls, although the former required twice the stimulus strength. 6. Slow IPSPs were found in the secondary focus and in controls, but not in the primary focus. They were sensitive to 3-amino-2-(4-chlorophenyl)-2-hydroxy-propylsulphonic acid (2-OH saclofen). The estimated conductances of slow IPSPs evoked by weak stimuli in the secondary focus were much smaller than in the controls. However, stimuli that could trigger epileptic discharges in the secondary focus, evoked 2-OH saclofen-sensitive slow IPSPs with estimated conductances approaching the controls. This marked increase in the slow IPSP did not occur when EPSPs, and epileptic bursts, were blocked with CNQX and AP-5, suggesting that a strong barrage of excitation is needed to generate full-sized slow IPSPs in the secondary focus.(ABSTRACT TRUNCATED AT 400 WORDS)

The Immune Response to Anti-Idiotype Antibodies Bearing an Internal Image Epitope of Tetanus Toxin/Toxoid

Primary immune responses to tetanus toxoid (TT) and primary and secondary immune responses to a rabbit TT internal image bearing anti-idiotype antibody (Ab2 beta 1) inoculated in Freund's complete adjuvant (FCA), saline (SAL) or syntex adjuvant formulation vehicle (SAF) via the intraperitoneal or subcutaneous route, were examined in mice. High anti-TT antibody (Ab3) titres are reported although the titre and persistence of the antibody response varied according to the adjuvant used in the priming and challenge inocula of Ab2 beta 1. Mouse Ab3 antibodies were elicited in mice inoculated with rabbit Ab2 beta 1 antibodies which in turn were elicited by an inoculum of mouse monoclonal anti-TT Ab1 antibody. Ab3 was shown to be identical to Ab1 by immunoblot analysis. Primary and secondary immune responses elicited by rabbit Ab2 beta 1 antibody protected mice against a lethal dose of tetanus toxin.

Tetanus toxin binding to neuroblastoma cells differentiated by antimitotic agents

We have examined the binding of tetanus toxin (TT) to surface receptors of neuroblastoma cells by flow cytometry following chemically induced differentiation. Cells were treated with mitomycin C, bromodeoxyuridine, prostaglandin E 1 or cyclic adenosine monophosphate at different doses, alone or in combination for 4 days. Cells extended long neurites within 24 h in the presence of prostaglandin/cyclic AMP or mitomycin/bromodeoxyuridine treatment while single-drug treatment was less efficient in morphological differentiation of these cells. Cells exposed to the drug combinations stopped growing after 3 days while flow-cytometric analysis of DNA levels of each cell stained with propidium iodide indicated that at least 60% of these cells were arrested in phase G 0/G 1 of the cell cycle. Drug-treated cultures were stained for TT binding by immunofluorescence of cells in suspension and analyzed by flow cytometry. Chemically differentiated N 2AB-1 cells were shown to bind significantly more TT than control cultures. Receptors for TT could be saturated by increasing doses of TT and differentiated cells bound twice as much toxin at saturation as did control cells. Immunofluorescence of TT binding to monolayers revealed staining in a stippled fashion along all neurites and cell bodies. These data support the concept that drugs which stimulate differentiation of neuroblastoma cells as determined by morphological and cell-cycle criteria also increase the presence of ganglioside receptors on the cell surface available for toxin binding.

Effect of tetanus toxin on K+ and Na+ concentrations in synaptosomes

A study was made of the effect of tetanus toxin (TT) in doses of 20-1000 MLD (for rats) on synaptosomes isolated from the rat brain cortex. TT produced a decrease in K+ content in synaptosomes. The effect depended on the dose of TT (I50=22 MLD). The content of Na+ remained unchanged. The action of TT depended on the time and the maximal effect was seen upon 60 minutes of incubation. TT inactivated by boiling or by antitoxin did not affect K+ content in synaptosomes. An increase of K+ concentration up to 17 mM in an incubation medium led to an increase in K+ content in TT-poisoned synaptosomes but not in the control ones. Possible changes in membrane electrogenesis in nerve terminals caused by TT are discussed.

Reversible effects of low doses of tetanus toxin on synaptic inhibition in the substantia nigra and turning behaviour in the rat

Reversible effects of low doses of tetanus toxin on synaptic inhibition in the substantia nigra and turning behaviour in the rat

Relations between the effect of tetanus toxin on the neuromuscular transmission and histological functional properties of various muscles of the rat.

Various doses of tetanus toxin were injected into three hind leg and two fore leg muscles of the rat. The neuromuscular transmission was tested by recording the mass action potential of the muscles elicited by a single electrical stimulus to the motor nerve after strong symptoms of local tetanus had developed. The muscle responses were depressed and blocked at lower toxin doses in the fast tibialis anterior than in the mixed gastrocnemius latemlis, while blocking of the slow soleus required the highest dose. The extensor carpi radialis and the flexor carpi ulnaris muscles showed medium sensitivity. In all five muscles the contraction time was measured and correlated with its individual minimal blocking dose. The more phasic (i.e., the faster) the muscle, the more sensitive its neuromuscular transmission was to tetanus toxin. The proportional distribution of red, white, and intermediate fibres, which are associated with specific end-plate types, was evaluated for the five muscles. The percentage of white fibres in the muscles displayed a very good negative correlation with the blocking dose. The relation between structures of end-plates and effects of tetanus toxin were analysed and it is suggested that the differences in sensitivity to tetanus toxin in the neuromuscular transmission in the five muscles is determined by a differential distribution of endplates with varying sensitivities to this toxin due to structural properties.

Use of acetylcholinesterase reactivators and of central cholinolytics in the treatment of experimental tetanus

The therapeutic efficacy of acetylcholinesterase reactivators dipyroxime and isonitrozin, and also of the central cholinolytics benactyzine and adiphenine, was studied in experiments on rabbits with tetanus produced by intravenous injection of one lethal dose of tetanus toxin. Dipyroxime in a dose of 25 mg/kg had no therapeutic action, and in doses of up to 30–40 mg/kg caused death of the animals. Benactyzine and adiphenine, in a dose of 3–4 mg/kg, abolished tonic convulsions for 1.5–2 h, and isonitrozin in a dose of 25 mg/kg did so for 4–5 h. After combined administration of reactivators and cholinolytics, convulsions were abolished for 4–5 h.

Tetanus Toxin Interactions with the Thyroid: Decreased Toxin Binding to Membranes from a Thyroid Tumor with a Thyrotropin Receptor Defect andin VivoStimulation of Thyroid Function

Normal rat thyroid membranes adsorb neurotoxicity when incubated with purified tetanus toxin. Membranes from a rat thyroid tumor with a thyrotropin receptor defect adsorb very little neurotoxicity when similarly evaluated. This inability of the tumor membranes to adsorb neurotoxicity is correlated with a defect in their ability to bind both 125I-labeled tetanus toxin and [125I]iodothyrotropin. The effect of tetanus toxin on the release of radioiodine from the thyroids of appropriately prepared mice has been measured by adapting methods used for the bioassay of thyrotropin. One minimum lethal dose of tetanus toxin given sc caused a significant release of radioiodine into the blood of mice 48 h after injection. In mice subjected to the stress of prior bleedings or anesthesia, the release of radioiodine from the thyroid by tetanus toxin was accelerated, i.e., the increase in blood radioiodine could be measured 24 h after injection. These results again suggest that tetanus toxin may interact with thyrotropin receptors on thyroid plasma membranes. The "sympathetic overactivity syndrome" seen in some patients with tetanus and the syndrome characterized as "thyroid storm" in patients with Graves' disease are discussed as they may relate to these observations.

The adjuvant effects of a tubercle bacillary lipid and lecithin: The immunization of mice by tetanus toxoid

Summary Mice were immunized by a single subcutaneous injection of tetanus toxoid (a) alone (b) with a tubercle bacillary lipid or (c) with a synthetic lecithin. The tubercle bacillary lipid or the lecithin were injected at the same time as the toxoid. The mice were challenged fourteen days later with a lethal dose of tetanus toxin. The tubercle bacillary lipid augmented the protection given to the mice if it were injected mixed with the toxoid, but not if it were injected by the intraperitoneal route. The augmenting effect appeared to be significant only with doses of toxoid that were effective alone, and increased with increasing dosage of the lipid Lecithin displayed a significant adjuvant effect only when injected in large doses together with the toxoid.

The efficacy of fragmented immune serum globulin in passive immunization.

The efficacy of an aged, fragmented preparation of immune serum globulin (human) as an agent for passive immunization was examined by comparing its performance in passive immunization with that of a fresh, unfragmented preparation. Guinea pigs passively immunized with the fresh preparation were protected against doses of tetanus toxin that were lethal to pigs which had received similar amounts of tetanus antitoxin as aged material.Monkeys passively immunized by intramuscular or intravenous injections of fresh immune serum globulin had levels of polio antibody in their serum which were consistently seven times higher than those produced by injection of the aged material. Urine collected from the monkeys treated with the aged material contained quantities of both polio and tetanus antibody as Fab fragment. After the intravenous injection of the aged material more than half of the injected antibody appeared in the urine within 24 hours.

Determination of cerebrosides in different parts of the brain of rabbits suffering from generalized tetanus.

The cerebroside content of the subcortical formations of the cerebral hemispheres of rabbits falls following injection of a lethal dose of tetanus toxin into a hind leg to a minimum on the 7–8th day, when the animals are moribund. This effect is more pronounced in the hemisphere contralateral to the injection site.

The effect of repeated administration of sublethal doses of tetanus toxin on the organism

When tetanus toxin is repeatedly administered to guinea pigs and mice in sublethal doses it causes an attack of tetanus resulting in death. This takes place when the sum total dose of administered toxin is considerably lower than the lethal dose. In single administration of the whole dose of the toxin (used formerly in several injections) the animals remain healthy or sustain an attack of tetanus from which they soon recover. The therapeutic serum was found to be ineffective in late treatment of tetanus which developed as a result of daily administration of sublethal doses of the toxin to guinea pigs.

Production of Anemia by Tetanus Toxin

SummarySmall sublethal doses of tetanus toxin produce a typical secondary anemia—low red cell count, reduced hemoglobin index, increased sedimentation rate. Injection of antitoxin produced a prompt return to normal, the red cell count rose rapidly as a result of large numbers of reticulocytes pouring into the system.The severe anemia following the administration of toxin and the prompt recovery following that of antitoxin may serve as a simple early diagnostic test of possible tetanus intoxication in wounded.