Ann Otol Rhinol Laryngol, 1989 Feb, 98(2), 130 - 4 Implantation of a recurrent laryngeal nerve stimulator for the treatment of spastic dysphonia; Friedman M et al.; Spastic dysphonia, a rare speech disorder, is characterized by strained phonation with excessively adducted vocal cords . Recurrent laryngeal nerve section, botulinum toxin injection into the vocalis-thyroarytenoid muscle complex, and other techniques have been used to treat this disorder . We have used percutaneous electrical stimulation of the recurrent laryngeal nerve with good results . Previous dog studies demonstrated the relative safety of an implantable recurrent laryngeal nerve stimulator . In this study, we directly stimulated the recurrent laryngeal nerve and vagus nerve in a dog without change in cardiorespiratory status . A Medtronic peripheral nerve stimulator was implanted in a patient with abductor spastic dysphonia . The cuff electrode was positioned around the recurrent laryngeal nerve and stimulation resulted in improvement in her voice . Extensive cardiopulmonary monitoring did not reveal any adverse response to stimulation and there was no discomfort to the patient . On the basis of the good results of this preliminary study, further study with long-term follow-up is under way. Dev Biol, 1989 Feb, 131(2), 401 - 14 Lack of fiber type selectivity during reinnervation of neonatal rabbit soleus muscle; Soha JM et al.; Fast and slow contracting fibers in neonatal mammalian skeletal muscle are each innervated in a highly specific manner by motor neurons of the corresponding type, even at an age when polyinnervation is widespread . Chemospecific recognition is a possible mechanism by which this pattern of innervation could be established . We have investigated this possibility by studying the degree of specificity during reinnervation of rabbit soleus muscle following nerve crush on Postnatal Day 1 or 4 . We assayed fiber type composition by measuring the twitch rise times of motor units within 2 days of the onset of functional reinnervation (5-6 days after nerve crush) . In contrast to the broad, bimodal distribution of single motor unit twitch rise times seen in normal muscles, motor units in reinnervated muscles yielded a narrower, unimodal distribution of rise times . Rise times of reinnervated units were intermediate to those of normal fast and slow units, suggesting that reinnervated units were composed of a mixture of fast and slow contracting fibers . An alternative possibility, that specific reinnervation was masked by contractile dedifferentiation of muscle fibers, was examined by maintaining a transmission blockade induced by botulinum toxin poisoning for an equivalent interval . Twitch rise times of treated motor units exhibited the distinctly bimodal distribution characteristic of normal muscles, suggesting that muscle fibers can retain contractile diversity during a transient period of denervation . We carried out computer simulations to estimate the amount of rise time diversity induced by varying degrees of specificity during reinnervation . Based on this analysis, we conclude that there is little if any selective reinnervation of muscle fiber types at the ages studied. J Neurochem, 1989 Feb, 52(2), 370 - 6 Actin involvement in exocytosis from PC12 cells: studies on the influence of botulinum C2 toxin on stimulated noradrenaline release; Matter K et al.; Botulinum C2 toxin is known to ADP-ribosylate actin . The toxin effect was studied on {3H}noradrenaline secretion of PC12 cells . {3H}Noradrenaline release was stimulated five- to 15-fold by carbachol (100 microM) or K+ (50 mM) and 10-30-fold by the ionophore A23187 (5 microM) . Pretreatment of PC12 cells with botulinum C2 toxin for 4-8 h at 20 degrees C, increased carbachol-, K+-, and A23187-induced, but not basal, {3H}noradrenaline release maximally 1.5-to three-fold, whereas approximately 75% of the cellular actin pool was ADP-ribosylated . Treatment of PC12 cells with botulinum C2 toxin for up to 1 h at 37 degrees C also increased stimulated {3H}noradrenaline secretion, whereas toxin treatment for greater than 1 h decreased the enhanced {3H}noradrenaline release stimulated by carbachol and K+ but not by A23187 . Concomitantly with toxin-induced stimulation of secretion, 20-50% of the cellular actin was ADP-ribosylated, whereas greater than 60% of actin was modified when exocytosis was attenuated . The data indicate that ADP-ribosylation of actin by botulinum C2 toxin largely modulates stimulation of {3H}noradrenaline release . Moreover, the biphasic toxin effects suggest that distinct mechanisms are involved in the role of actin in secretion. Mol Cell Biochem, 1989 Jan 23, 85(1), 67 - 73 Structure of heavy and light chain subunits of type A botulinum neurotoxin analyzed by circular dichroism and fluorescence measurements; Singh BR et al.; The secondary and tertiary structural features of botulinum neurotoxin (NT) serotype A, a dichain protein (Mr 145,000), and its two subunits, the heavy (H) and light (L) chains (Mr 97,000 and 53,000, respectively) were examined using circular dichroism and fluorescence spectorscopy . Nearly 70% of the amino acid residues in each of the three polypeptide preparations were found in ordered structure (sum of alpha helix, beta sheet and beta turns) . Also, the alpha helix, beta sheet, beta turns and random coil contents of the dichain NT were nearly equal to the weighted mean of each of these secondary structure parameters of the L and H chains; e.g., sum of alpha helix of L chain (22%) and H chain (18.7%), as weighted mean, 19.8% was similar to that of NT (20%) . These agreements suggested that the secondary structures of the subunits of the dichain NT do not significantly change when they are separated as isolated L and H chains . Fluorescence emission maximum of L chain, 4 nm less (blue shift) than that of H chain, suggested relatively more hydrophobic environment of fluorescent tryptophan residue(s) of L chain . Tryptophan fluorescence quantum yields of L chain, H chain and the NT, 0.072, 0.174 and 0.197, respectively, suggested that a) an alteration in the micro-environment of the tryptophan residues was possibly caused by interactions of L and H chain subunits of the NT and b) quantum yields for L and H chains were altered when they are together as subunits of the NT . Possible implications of structural features of the L and H chains, their interactions and the molecular mechanism of action of botulinum NT are assessed. Neurosci Lett, 1989 Jan 16, 96(2), 127 - 32 Sprouting of frog motor nerve terminals after long-term paralysis by botulinum type A toxin; Diaz J et al.; A single sublethal injection of botulinum type A toxin (BoTx-A) to winter frogs induced a general and complete paralysis of skeletal muscles, which lasted several months . Quantitative analysis of 483 end-plates from 8 BoTx-A poisoned muscles and 495 endplates from 8 control muscles revealed a higher and significant incidence of terminal and ultraterminal sprouts in poisoned junctions when taking into account the normal remodelling of motor innervation . We conclude that prolonged neuromuscular blockade by BoTx-A results in the extension of the nerve terminal arborization. FEBS Lett, 1989 Jan 16, 243(1), 70 - 6 Purification of the 22 kDa protein substrate of botulinum ADP-ribosyltransferase C3 from porcine brain cytosol and its characterization as a GTP-binding protein highly homologous to the rho gene product; Braun U et al.; The 22 kDa protein substrate of botulinum ADP-ribosyltransferase C3 was purified from porcine brain cytosol by acetone precipitation, CM-Sephadex, octyl-Sepharose and TSK phenyl-5PW HPLC chromatography to apparent homogeneity . ADP-ribosylation of the protein was increased by guanine nucleotides (GTP, GDP, GTP gamma S, each 100 microM) but not by GMP, ATP or ATP gamma S . The purified 22 kDa protein bound maximally 0.9 mol {35S}GTP gamma S and hydrolyzed GTP with the rate 0.007 mol per mol protein . Amino acid sequences were obtained from two tryptic peptides, selected from an in situ digestion of Immobilon electrotransferred, gel purified ADP-ribosylated substrate . The two sequences obtained, cover 23 residues from the corresponding sequences in human rho. Biochem Biophys Res Commun, 1989 Jan 16, 158(1), 209 - 13 The rho gene product expressed in E . coli is a substrate of botulinum ADP-ribosyltransferase C3; Aktories K et al.; The ras-related rho A protein expressed in E . coli, was ADP-ribosylated by botulinum ADP-ribosyltransferase C3 . C3 also modified the valine-14 mutant rho protein but not the products of H-ras, R-ras, ral, ypt, and rap 1 genes . A ras-rho chimaera consisting of 60 amino acids from the amino terminus of ras fused to 133 amino acids from the carboxy terminus of rho was not modified by C3 . Antibodies raised against the porcine brain cytosolic substrate of C3 cross reacted with the rho, valine-14 rho and ras-rho proteins, but not with the gene products of H-ras, R-ras, ral or rap 1 . Polyclonal anti-H-ras antibodies cross reacted with H-ras but not with ral, rho, or the C3 substrate purified from porcine brain. Infect Immun, 1989 Jan, 57(1), 18 - 22 Sequence homology between tetanus and botulinum toxins detected by an antipeptide antibody; Halpern JL et al.; The extent of immunological similarity between tetanus toxin and botulinum toxins A, B, C1, and E was studied by using 10 antibodies produced against synthetic peptides representing different sequences of tetanus toxin, mouse antitetanus serum, and human Tetanus Immune Globulin . Antibodies produced against the synthetic peptides recognized tetanus toxin in an enzyme-linked immunosorbent assay and on Western blots (immunoblots) but did not appear to recognize the native protein . One of the antitetanus peptide antibodies, which was produced against a peptide from the amino terminal, cross-reacted with three of the four botulinum toxins on immunoblots . This antibody, 1, reacted strongly with botulinum toxins B and C1 and weakly with E but did not recognize type A toxin . None of the other peptide antibodies cross-reacted with the botulinum toxins . Mouse antitetanus serum and human Tetanus Immune Globulin did not recognize any of the botulinum toxins on immunoblots . The amino-terminal region of the light chain of tetanus toxin and botulinum toxin types A, B, C1, and E are known to have sequence homology . Our data demonstrate that for tetanus toxin and botulinum toxin types B, C1, and E this region also has immunological homology . Type A, which has the least amount of homology with tetanus toxin in this region, does not share this immunological homology . These data also suggest that although the native structures of tetanus and botulinum toxins have relatively few common immunological determinants, the two toxins may contain short stretches of identical or very similar amino acid sequences. Mov Disord, 1989, 4(4), 287 - 96 Adductor laryngeal dystonia (spastic dysphonia): treatment with local injections of botulinum toxin (Botox); Brin MF et al.; Adductor spastic dysphonia (SD) is a laryngeal dystonia characterized by a choked, constrained voice pattern with breaks in vocal flow . Treatment with a variety of therapies including speech and pharmacotherapy have minimal benefit; only one-third of patients undergoing recurrent laryngeal nerve section have benefitted at 3 years . We have used local injections of botulinum toxin (Botox) bilaterally into vocalis muscles in 42 patients with SD . Injections were through a teflon-coated hollow electromyography (EMG) recording needle . Unilateral small doses (2.5-3.75 U) were of no clinical benefit . Bilateral small doses resulted in sustained improvement lasting 84.4 +/- 9.3 days . The degree of improvement was 61.1 +/- 4.6% . Common side-effects included a brief period of breathy hypophonia (8.5 +/- 2.5 days) and a mild sensation of choking/aspiration of fluids (1.7 +/- 0.6 days); there were no serious adverse effects . Vocal cord paralysis was not necessary for benefit . Follow-up vocalis muscle EMGs revealed denervation . All patients responded to retreatment (longest follow-up 3.5 years) . Patients with prior recurrent laryngeal nerve surgery and residual uncomplicated dysphonia had similar results . Our results indicate that local injection of low-dose Botox is the treatment of choice for SD. Neuroscience, 1989, 31(2), 521 - 7 Increase in reactive cholesterol in the presynaptic membrane of depolarized Torpedo synaptosomes: blockade by botulinum toxin type A; Egea G et al.; We have investigated the redistribution of filipin-cholesterol complexes at freeze-fractured presynaptic membrane of pure cholinergic synaptosomes isolated from Torpedo electric organ during acetylcholine release . After chemical depolarization, filipin-induced lesions increase at the presynaptic membrane . These changes do not take place when synaptosomes are stimulated in a calcium-free medium . Botulinum neurotoxin type A blocks both acetylcholine release and the rearrangement of filipin-induced lesions induced by depolarization . Since botulinum neurotoxin type A does not block either membrane depolarization or calcium entry into the nerve terminal, our results suggest that the redistribution of filipin-cholesterol complexes is linked to the acetylcholine release process. Toxicon, 1989, 27(8), 849 - 59 Gangliosides mediate inhibitory effects of tetanus and botulinum A neurotoxins on exocytosis in chromaffin cells; Marxen P et al.; Bovine chromaffin cells in monolayer culture were preloaded with 3H-NA (noradrenaline) and subsequently stimulated with carbachol . Botulinum A neurotoxin partially inhibited the evoked release of 3H-NA and the basal efflux of the hormone . The inhibition of evoked release did not exceed 40%, although the cells were exposed to 10 micrograms/ml of toxin for 6 days . The inhibitory effect of botulinum A neurotoxin was neutralized by its antibodies . In contrast to botulinum A neurotoxin, tetanus toxin at even higher concentrations did not influence evoked release . This difference in sensitivity could be explained by the ganglioside pattern of chromaffin cells . Ganglioside GD1a, a putative receptor for botulinum A neurotoxin, could be identified in lipophilic extracts, whereas the tetanus toxin binding gangliosides GT1b and GD1b could not be detected by means of thin-layer chromatography . Treatment of the cells with neuraminidase abolished both, GD1a and the inhibitory effect of botulinum A neurotoxin . Incubation of chromaffin cells with a mixture of gangliosides (21% GM1, 44% GD1a, 15% GD1b, 20% GT1b) not only increased the efficacy of botulinum A neurotoxin but also made the cells sensitive towards tetanus toxin . The concentration-response curve of botulinum A neurotoxin was shifted to the left about five-fold and the maximum inhibition of evoked release was increased up to 60%, even though the cells were exposed to the toxin for 3 days only . In contrast, the maximum inhibition that could be achieved by tetanus toxin was 40% . The results indicate that polysialogangliosides are important for the intracellular accumulation of these clostridial neurotoxins. J Neurol Neurosurg Psychiatry, 1989 Jan, 52(1), 57 - 62 Vestibulo-ocular abnormalities in spasmodic torticollis before and after botulinum toxin injections; Stell R et al.; In order to establish whether vestibular abnormalities often found in spasmodic torticollis are secondary to the abnormal head posture, the vestibulo-ocular reflex (VOR) was studied in eight patients before and after correction of head posture with botulinum toxin . Eye movements were recorded in the dark during sinusoidal and velocity step rotation . Four patients showed a significantly asymmetric response, with the slow phase of the VOR more active ipsilateral to the torticollis (chin) . Despite significant improvement of the head posture in all patients for up to 10 weeks following treatment, no correction of the vestibular asymmetry occurred . This suggests that the VOR abnormalities are not caused by the head posture itself . We interpret the findings as evidence of primary involvement of the vestibular system in torticollis and we postulate a widespread derangement of the sensory-motor mechanisms controlling head posture in this disease. Prog Brain Res, 1989, 80, 183 - 96; discussion 171-2 Open-loop and closed-loop optokinetic nystagmus in squirrel monkeys (Saimiri sciureus) and in man; Behrens F et al.; Horizontal optokinetic nystagmus (OKN) was measured in 3 normal Squirrel monkeys by means of the electromagnetic search coil technique . Binocular and monocular stimulation of each eye to the left and right by moving vertical stripe patterns of 2.37 or 15 degree period were applied at angular velocities of 0.5 to 400 deg/s . After measurement of horizontal OKN under normal conditions, open-loop OKN gain was determined by monocular stimulation of an eyeball immobilized by means of retrobulbar injections of 11 units botulinum toxin (BoTx type A) and compared with the pre-injection data or with monocular stimulation of the other eye, which remained mobile . In normal Squirrel monkeys gain of optokinetic nystagmus reached values between 0.8 and 0.97 at angular velocities below 1.5 deg/s . Gain under these conditions was related to stimulus angular velocities Vs, i.e . Ge = Ve/Vs . A slightly higher gain was found for binocular than for monocular stimulation . No significant differences were found in OKN when monocular stimulation in the naso-temporal and in the temporo-nasal direction was applied . The upper cut-off angular velocity (-3 dB-point) reached values of 180-230 deg/s, significantly above those observed in man under similar stimulus conditions . Monocular optokinetic stimulation of an immobilized eye led to vigorous optokinetic nystagmus and OKAN of the other eye, whereby maximum gain (Gi = Ve/Vr) was found to be between 20 and 30 at lower retinal stimulus velocities (2-5 deg/s) . Gain was related to retinal stimulus velocity Vr . Increase in Vr above 10 deg/s led to a decrease in gain with a slope of about 20 dB per decade . Measurement of gain of closed-loop OKN related to retinal stimulus velocity Vr (which was determined by the difference between Vs and Ve) led to a similar dependence of OKN as in closed-loop stimulus conditions . Differences in sensitivity between the temporal and the nasal visual hemifield stimulation evoking horizontal open-loop OKN are described . Directional selectivity appeared in these experiments . Open-loop OKN data from a human subject are reported . With highly attentive horizontal optokinetic gaze nystagmus, Ve depended on the duration of the pursuit phases of OKN . Ve accelerated with the duration of the individual slow phase of OKN and was reset by each backward saccade (of the covered mobile eye) . OKN gain was considerably smaller when the subject intentionally pursued as many stripes as possible of the 1.15 degree period stripe pattern (gain related to Vr about 1.5-3).(ABSTRACT TRUNCATED AT 400 WORDS) Neurology, 1989 Jan, 39(1), 80 - 4 Controlled trial of botulinum toxin injections in the treatment of spasmodic torticollis; Gelb DJ et al.; We administered local injections of botulinum toxin to 20 patients with torticollis in a blinded, placebo-controlled study . Each patient received four sets of injections: three different doses of botulinum toxin and one placebo . The order of the sessions was random and unknown to the patients . Sixteen of the patients (80%) reported subjective improvement to at least one dose of botulinum toxin; 11 (55%) reported substantial improvement . No objective benefit was documented . Side effects were minor and transient, although dysphagia occurred in four . Some patients reported that the effect waned despite persistent relaxation or even flaccidity of previously overactive muscles, suggesting a change in the pattern of muscle activity after botulinum toxin injections. Eye, 1989, 3 ( Pt 4), 409 - 14 Doppler ultrasound velocity mapping of extra-ocular muscles: a preliminary report; Canning CR et al.; Colour doppler imaging and conventional spectral doppler/B-mode techniques were used to detect and quantify rectus muscle movement during voluntary saccades . A velocity gradient was evident in all muscles studied--low velocities near the muscle origin at the back of the orbit increasing linearly to a maximum near the muscle insertion on the globe . A consistent reduction in velocity occurred along muscles injected with botulinum toxin . Doppler ultrasound complements current clinical eye movement recording techniques--electronystagmography, infrared light reflection methods and magnetic induction methods--insofar as it detects movement in parts of the muscle itself rather than movement of the globe secondary to muscle contraction . Future developments in colour doppler imaging will make the technique clinically more applicable. Eye, 1989, 3 ( Pt 4), 391 - 400 The role of botulinum toxin in the management of sixth nerve palsy; Fitzsimons R et al.; Fifty-five patients with sixth nerve palsy have been treated with Botulinum toxin injection to the antagonist medial rectus, either in isolation or in combination with rectus muscle surgery . Forty of these patients (72 per cent) obtained significant benefit from injection at some stage in their management . Botulinum toxin has a major role in conjunction with transposition muscle surgery for the treatment of complete unrecovered sixth nerve palsy . In less severe paresis, a functional cure may be obtained in a significant number of cases with the use of Botulinum toxin alone, 37 per cent in this series . No serious complications were observed . In view of the safety of this procedure it is reasonable to consider an injection of Botulinum toxin in any adult patient with a persisting sixth nerve palsy. J Neural Transm Park Dis Dement Sect, 1989, 1(3), 229 - 42 Effects of botulinum neurotoxin and Lambert-Eaton myasthenic syndrome IgG at mouse nerve terminals; Lande S et al.; The interaction between two presynaptically acting agents, Lambert-Eaton myasthenic syndrome (LEMS) immunoglobulin G (IgG) and purified botulinum neurotoxin (BoNT) type A, was studied . Intracellular microelectrode recordings were carried out on mouse muscles after injection with LEMS IgG . BoNT was either injected before recordings were made or applied in vitro . The time course of the in vitro actions of BoNT on miniature end-plate potential and end-plate potential parameters were not affected by pretreatment with LEMS IgG . After in vivo injection of BoNT, end-plate potential quantal content was reduced to less than 2% of control values, whether or not LEMS IgG had also been previously given . Quantitative electron-microscope autoradiographical analysis showed that neither the binding of 125I-BoNT to acceptors on the nerve terminal membrane nor the pattern of its internalisation were affected by pretreatment with LEMS IgG . We conclude that the effects of BoNT are not affected by LEMS IgG, suggesting different presynaptic binding sites for the two agents. Toxicon, 1989, 27(10), 1143 - 50 Modification of carboxyl groups in botulinum neurotoxin types A and E; Woody MA et al.; Effects of chemical modification of carboxyl groups of botulinum neurotoxin serotypes A and E were studied by using a water soluble carbodiimide-nucleophile reaction that is highly specific for modifying carboxyl groups of proteins . In both types A and E, increasing levels of the reagents, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and norleucine methyl ester or glycine methyl ester, at pH 4.8 caused increased loss of toxicity . More glycine could be incorporated than norleucine . Amino acid analysis did not reveal modification of any amino acid residue other than carboxyl groups (possible reaction of sulfhydryl groups was not studied) . Loss of one carboxyl group did not severely affect toxicity, but modification of three carboxyl groups caused greater than 95% detoxification in both types . Complete detoxification could not be achieved with any amount of the reagents . Modification of three to five carboxyl groups did not affect serological activity. Toxicon, 1989, 27(9), 989 - 93 Botulinum C2 toxin treatment increases the G-actin pool in intact chicken cells: a model for the cytopathic action of actin-ADP-ribosylating toxins; Aktories K et al.; Botulinum C2 toxin ADP-ribosylates actin in intact chicken embryo cells in a concentration-dependent manner . This effect correlates with an enhancement in the inhibitory potency of the respective cell lysates on DNAse I activity, indicating an increase in the cellular G-actin content of toxin-treated cells . The data support our view, that ADP-ribosylation of cellular actin with subsequent depolymerization of cytoskeleton-associated F-actin to monomeric G-actin is involved in the cytotoxic effects of botulinum C2 toxin . A model of the cytopathic action of actin-ADP-ribosylating toxins is presented. Acta Neuropathol (Berl), 1989, 78(1), 72 - 85 Dithiobiuret neurotoxicity: an ultrastructural investigation of the lesion in preterminal axons and motor endplates in the rat lumbrical muscle; Jones HB; 2,4-Dithiobiuret was given i.p . to rats for 4 days at a daily dosage of 1 mg/kg and the development of the lesion associated with neuromuscular dysfunction studied in hindlimb lumbrical muscles . The first morphological indication of neurointoxication was the appearance in some motor endplates of masses of branching tubular smooth endoplasmic reticulum (SER) on day 2 which correlated with the initial functional disturbances . By the 3rd day, most motor endplates were distended by accumulations of dense-cored, lucent and synaptic vesicles, abnormally swollen mitochondria, intermediate filaments and branching, tubular SER . Evidence of collateral axonal sprouting was seen first at this time . On days 4 and 5, many motor endplates were markedly enlarged and showed axoplasmic organelle congestion . A significant increase in synaptic vesicle size was noted at these times in some terminals . Interposition of Schwann cell processes between the pre- and postsynaptic membranes and terminal retraction was now evident . Some intramuscular nerves showed hydropic Schwann cell cytoplasm with separation of the outermost myelin lamellae, mitochondrial swelling and adaxonal vacuoles as early as the 1st day . Proliferation and segregation of SER around central cores of neurofilaments was seen in myelinated nerve fibres and preterminals on the 3rd day . At this and later times accumulations of SER and swollen mitochondria were found at sites of axonal varicosities and at the paranodal constrictions at nodes of Ranvier . These ultrastructural data are discussed with regard to reduced terminal Ca2+ content (demonstrated by oxalate-pyroantimonate cytochemistry) and compared with the sequelae of botulinum intoxication. Proc Natl Acad Sci U S A, 1989 Jan, 86(1), 372 - 6 Botulinum toxin type A blocks the morphological changes induced by chemical stimulation on the presynaptic membrane of Torpedo synaptosomes; Marsal J et al.; The action of botulinum neurotoxin on acetylcholine release, and on the structural changes at the presynaptic membrane associated with the transmitter release, was studied by using a subcellular fraction of cholinergic nerve terminals (synaptosomes) isolated from the Torpedo electric organ . Acetylcholine and ATP release were continuously monitored by chemiluminescent methods . To catch the membrane morphological changes, the quick-freezing method was applied . Our results show that botulinum neurotoxin inhibits the release of acetylcholine from these isolated nerve terminals in a dose-dependent manner, whereas ATP release is not affected . The maximal inhibition (70%) is achieved at neurotoxin concentrations as low as 125 pM with an incubation time of 6 min . This effect is not linked to an alteration of the integrity of the synaptosomes since, after poisoning by botulinum neurotoxin type A, they show a nonmodified occluded lactate dehydrogenase activity . Moreover, membrane potential is not altered by the toxin with respect to the control, either in resting condition or after potassium depolarization . In addition to acetylcholine release inhibition, botulinum neurotoxin blocks the rearrangement of the presynaptic intramembrane particles induced by potassium stimulation . The action of botulinum neurotoxin suggests that the intramembrane particle rearrangement is related to the acetylcholine secretion induced by potassium stimulation in synaptosomes isolated from the electric organ of Torpedo marmorata. J Physiol, 1988 Dec, 407, 263 - 74 Neural regulation of {3H}saxitoxin binding site numbers in rat neonatal muscle; Bambrick LL et al.; 1 . Neural regulation of the density of sodium (Na+) channels in rat muscle was studied by measuring specific binding of tritiated saxitoxin ({3H}STX) to muscles from rat hindlimbs during normal development and in rats in which neuromuscular function was interrupted by sciatic nerve section or neuromuscular blockade with botulinum toxin (BoTX) . 2 . The normal developmental increase in {3H}STX binding site numbers followed a simple exponential with a time constant of 12 days . The most rapid incorporation of channels coincided with the onset of accelerated muscle growth and increased neuromuscular activity at 2 weeks of age . 3 . Elimination of neuromuscular activity retarded muscle growth and inhibited the normal incorporation of Na+ channels into neonatal muscle . Muscles denervation was more effective than BoTX paralysis: denervation at 2 weeks of age prevented the normal 3-fold increase in the binding site density between 2 and 3 weeks of age while age-matched BoTX-treated muscles incorporated an average of 66% of the normal Na+ channel incorporation . 4 . Denervation and BoTX treatment were equally effective in reducing the numbers of {3H}STX binding sites in adult muscle . A reduction of 30% in binding sites brought the numbers to levels which corresponded with levels normally seen in muscles at 3 weeks of neonatal development . 5 . It was concluded that the neural influence on incorporation of Na+ channels into membranes of neonatal muscle is, at least in part, mediated by neuromuscular activity. Eur J Biochem, 1988 Nov 15, 177(3), 683 - 91 Involvement of the constituent chains of botulinum neurotoxins A and B in the blockade of neurotransmitter release; Maisey EA et al.; 1 . The abilities of botulinum neurotoxins, types A and B (single and two-chain forms) to inactivate an intraneuronal component required for transmitter release were quantified in a phrenic-nerve-diaphragm preparation, cerebrocortical synaptosomes or the buccal ganglion of Aplysia californica and compared with the mouse toxicity assay . 2 . Homogeneous preparations of the individually renatured polypeptide chains of both toxin types showed low residual toxicity in the whole animal and had no effect on neurotransmission in all three systems, when tested singly . 3 . Mixtures of individually renatured heavy chain, from type A or B, and either light chain proved very effective in blocking the evoked release of acetylcholine when bath-applied to the buccal ganglion of Aplysia whilst they were relatively inactive on mammalian nerve terminals, indicating a less efficient uptake of the polypeptides in the latter . 4 . When renatured together, the homologous, but not the heterologous, chains of each toxin type yielded toxic, disulphide-linked two-chain species . 5 . A role for the heavy chain alone in acceptor recognition and membrane translocation was implicated by the blockade of acetylcholine release produced when light chain was applied to a ganglion of Aplysia previously bathed in heavy chain and washed extensively . No blockade was observed when the order of application of the two chains was reversed . 6 . These findings are discussed in the context of the intracellular requirement for both the constituent toxin chains for toxicity, and in the apparent need for these chains to be linked via a disulphide bond for uptake in rodents but not in Aplysia. Am J Ophthalmol, 1988 Nov 15, 106(5), 584 - 6 Treatment of acquired nystagmus with botulinum A toxin; Helveston EM et al.; We injected botulinum A toxin into the retrobulbar space of one eye each in two patients who had acquired nystagmus with oscillopsia and decreased vision . After injection of 25 units of botulinum A toxin, visual acuity improved from 20/80 to 20/30 in one patient, and both patients were able to read and watch television . Improved vision lasted from five to 13 weeks . No adverse side effects were observed after a total of five injections in each patient. J Biol Chem, 1988 Nov 15, 263(32), 16744 - 9 Purification and characterization of the 22,000-dalton GTP-binding protein substrate for ADP-ribosylation by botulinum toxin, G22K; Bokoch GM et al.; GTP-binding proteins were purified from human neutrophils, including a 40,000-Da pertussis toxin substrate (Gn) and 22,000-, 24,000-, and 26,000-Da proteins, termed G22K, G24K, and G26K, respectively . The latter proteins were shown to be immunologically unrelated to Gn . G22K cross-reacted with anti-ras monoclonal antibody 142-24EO5, but not with monoclonal antibody Y13-259 . A single 22,000-Da substrate for botulinum toxin-catalyzed ADP-ribosylation present in neutrophil membranes co-migrated upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis with G22K . In the presence of a cytosolic factor, G22K could serve as a specific botulinum toxin substrate . The 22,000-Da botulinum toxin substrate in neutrophil membranes could be immunoprecipitated by antibody 142-24EO5, but not by antibody Y13-259 . G22K appears to be a unique GTP-binding protein which serves as a substrate for ADP-ribosylation by a component of botulinum toxin and which may be involved in exocytotic secretion or cellular differentiation. J Biol Chem, 1988 Nov 5, 263(31), 16303 - 8 ADP-ribosylation of the bovine brain rho protein by botulinum toxin type C1; Kikuchi A et al.; We have separated at least six GTP-binding proteins (G proteins) with Mr values between 20,000 and 25,000 from bovine brain crude membranes (Kikuchi, A., Yamashita, T., Kawata, M., Yamamoto, K., Ideda, K., Tanimoto, T., and Takai, Y . (1988) J . Biol . Chem . 263, 2897-2904) . Three of these G proteins were copurified with the proteins ADP-ribosylated by botulinum toxin type C1 . One G protein ADP-ribosylated by this toxin was identified to be the bovine brain rho protein (rho p20) which was purified to near homogeneity (Yamamoto, K., Kondo, J., Hishida, T., Teranishi, Y., and Takai, Y . (1988) J . Biol . Chem . 263, 9926-9932) . rho p20 was ADP-ribosylated by botulinum toxin type C1 in time- and dose-dependent manners . About 0.4 mol of ADP-ribose was maximally incorporated into 1 mol of rho p20 . The ADP-ribosylation of rho p20 was dependent on the presence of Mg2+ . GTP enhanced the ADP-ribosylation in the presence of a low concentration (50 nM) of Mg2+ but not in the presence of a high concentration (0.5 mM) of Mg2+ . The high concentration of Mg2+ fully stimulated the ADP-ribosylation even in the absence of GTP . The ADP-ribosylation of rho p20 did not affect its GTP gamma S-binding and GTPase activities . These results indicate that there are at least three G proteins ADP-ribosylated by botulinum toxin type C1 in bovine brain crude membranes and that one of them is rho p20 . Two other G proteins have not yet been identified, but neither the c-ras protein, ADP-ribosylation factor for Gs, nor a G protein with a Mr of 24,000 was ADP-ribosylated by this toxin. Riv Neurol, 1988 Nov-Dec, 58(6), 245 - 8 Use of botulinum toxin in Meige's disease; Maurri S et al.; Four patients with severe Meige's disease (blepharospasm-oromandibular dystonia) have been treated, after having given an informed consent, by local injections of purified botulinum toxin type "A" . Previous systemic therapy with anticholinergics, dopamine antagonists and other drugs had been unsuccessful in all these subjects . Each patient was treated by saline solution injected with the same method as botulinum toxin, just once . The self-evaluation of patients and the clinical evaluation that some of us- unaware of the kind of therapy which had been performed- gave to the symptoms on the basis of videotapes, for each session of injection, showed that the injections of botulinum toxin are effective in the treatment of such disorder . The duration of the beneficial effect was slightly shorter in these patients than in patients with blepharospasm treated by the same method. J Clin Microbiol, 1988 Nov, 26(11), 2351 - 6 Human immune response to botulinum pentavalent (ABCDE) toxoid determined by a neutralization test and by an enzyme-linked immunosorbent assay; Siegel LS; To determine the immune status of persons receiving botulinum pentavalent (ABCDE) toxoid and to evaluate the effectiveness of the vaccine, we surveyed immunized individuals for neutralizing antibodies to type A and to type B botulinum toxins . After the primary series of three immunizations administered at 0, 2, and 12 weeks, 21 of 23 persons tested (91%) had a titer for type A that was greater than or equal to 0.08 international units (IU)/ml, and 18 (78%) had a titer for type B of greater than or equal to 0.02 IU/ml . (One international unit is defined as the amount of antibody neutralizing 10,000 mouse 50% lethal doses of type A or B botulinum toxin) . Just before the first annual booster, 10 of 21 (48%) and 14 of 21 (67%) people lacked a detectable titer for type A and for type B, respectively . After the first booster, all individuals tested had a demonstrable titer to both types A and B . Of 77 persons who had previously received from one to eight boosts of the toxoid, 74 (96%) had an A titer of greater than or equal to 0.25 IU/ml and would not require an additional booster, according to the recommendations of the Centers for disease Control . However, only 44 of 77 (57%) had a B titer of greater than or equal to 0.25 IU/ml . In each group by booster number, even the group having had eight boosts, at least one person would require reimmunization on the basis of B titer . There was a wide range of antibody levels among individuals at the same point in the immunization scheme . Results from an enzyme linked immunosorbent assay, with purified type A or type B neurotoxin as the capture antigen, were compared with neutralization test results on 186 serum samples for type A and 168 samples for type B . Statistically, the correlation coefficients for results from the two assays were high (r = 0.69, P < 0.0001, for type A and r = 0.77, P < 0.0001, for type B) . However, due to the wide dispersion of values obtained, using enzyme-linked immunosorbent assay results to predict neutralizing antibody levels is unwarranted. Ophthalmology, 1988 Nov, 95(11), 1535 - 42 Treatment of sixth nerve palsy in adults with combined botulinum toxin chemodenervation and surgery; Fitzsimons R et al.; This study reports the results of treating unrecovered sixth nerve palsy in adults with a combination of botulinum toxin and surgery . Twenty-two adults, 11 with unilateral and 11 with bilateral unrecovered sixth nerve palsy, were treated with injections of botulinum toxin to the contracted medial rectus followed by transposition surgery to the vertical rectus muscles . This management technique produced a satisfactory reduction in esotropia, averaging 46 prism diopters (PD), comparable with that achieved by conventional surgery in other series . The advantages of this form of treatment are discussed. Ophthalmology, 1988 Nov, 95(11), 1529 - 34 Long-term results and complications of botulinum A toxin in the treatment of blepharospasm; Dutton JJ et al.; The authors review their long-term results and complications with the use of botulinum A toxin in the treatment of facial dystonias . Two hundred thirty-two patients in three diagnostic groups--essential blepharospasm, hemifacial spasm, and Meige's syndrome--were treated with botulinum A toxin . A total of 1044 treatments were given over a 4-year period . A reduction in orbicularis spasm intensity was noted in 1012 (96.9%) treatments (mean duration, 13.3 weeks) . There was no clear relationship between toxin dose and the amount of spasm reduction or duration of response, and average duration of beneficial effect remained constant from the first through the twelfth injections . Complications occurred in 236 (22.6%) treatments . In most cases, these were local and transient . Symptomatic dry eye was the most common side effect, noted in 7.5% of cases . Ptosis was reported in 7.3% of treatments and photophobia in 2.5% . Diplopia involving the inferior oblique or lateral rectus muscles was seen in less than 1% of cases . There were no differences in degree of response or in complications among the three diagnostic groups, although there was a slight difference in duration of effect . Patients who had undergone previous eyelid surgery for blepharospasm did not respond differently from those without prior surgery. Brain Res, 1988 Nov 1, 463(2), 218 - 22 Motor nerve outgrowth: reduced capacity for sprouting in the terminals of longer axons; Pestronk A et al.; The ability of axons to grow or sprout can vary considerably . In this study we have examined the relation between axon length and the abundance of outgrowth from motor nerve terminals in vivo . Outgrowth from nerve terminals was evoked using botulinum toxin . Terminal axons, sprouts and neuromuscular junctions were visualized using a cholinesterase-silver stain . The amount of axonal outgrowth was compared in several proximal (e.g . rhomboid and paraspinous), intermediate, and distal (e.g . soleus and foot) muscles . Our results show that sprouting is generally more abundant in proximal than in distal muscles . There is a significant inverse correlation between nerve length and the abundance of sprouting from terminal axons . Thus, terminals of short axons appear to have more ability or potential to sprout than those of long axons. J Neurol Sci, 1988 Nov, 87(2-3), 175 - 85 Axonal sprouting after botulinum toxin does not elicit a histological axon reaction; Pamphlett R; In an attempt to determine which elements of the axon reaction are essential for early axonal outgrowth, axonal sprouting was induced with botulinum toxin (BoTx) and the nerve cell body changes compared with those accompanying axonal growth after nerve trauma . Anterior horn cells of mice were examined histologically at times ranging from 3 days to 3 weeks after either BoTx hindlimb injection or sciatic nerve crush . After sciatic nerve crush there was dispersion of Nissl substance, increase in cell body size, and an increase in neurofilament protein staining . None of these changes were found after BoTx-induced terminal axonal sprouting, suggesting that these morphological features of the axon reaction are not essential for early axonal outgrowth. Aust N Z J Ophthalmol, 1988 Nov, 16(4), 333 - 5 Botulinum toxin--the rationale of its use; Dunlop C; Treatment with Oculinum, (Botulinum toxin, Type A), may induce three possible effects . These are a pharmacologic inhibitory effect, a mechanical effect and a sensory effect. CMAJ, 1988 Nov 1, 139(9), 837 - 44 Cranial dystonia, blepharospasm and hemifacial spasm: clinical features and treatment, including the use of botulinum toxin; Kraft SP et al.; Blepharospasm, the most frequent feature of cranial dystonia, and hemifacial spasm are two involuntary movement disorders that affect facial muscles . The cause of blepharospasm and other forms of cranial dystonia is not known . Hemifacial spasm is usually due to compression of the seventh cranial nerve at its exit from the brain stem . Cranial dystonia may result in severe disability . Hemifacial spasm tends to be much less disabling but may cause considerable distress and embarrassment . Patients affected with these disorders are often mistakenly considered to have psychiatric problems . Although the two disorders are quite distinct pathophysiologically, therapy with botulinum toxin has proven very effective in both . We review the clinical features, proposed pathophysiologic features, differential diagnosis and treatment, including the use of botulinum toxin, of cranial dystonia and hemifacial spasm. Neurology, 1988 Nov, 38(11), 1780 - 3 Neuromuscular effects distant from the site of botulinum neurotoxin injection; Olney RK et al.; We assessed the severity and temporal profile of distant neuromuscular effects from a single dose (280 units) of botulinum neurotoxin injected into neck muscles for torticollis . We performed single-fiber EMG studies on the biceps brachii of six patients to measure jitter (20 pairs) and fiber density on the initial treatment day and then again, at least once more, after 2 to 12 weeks . No patient developed weakness beyond the neck muscles or decrement of the biceps response to repetitive 3-Hz nerve stimulation . Between the baseline and the last follow-up study, the average of mean MCD increased from 29 microseconds to 38 microseconds (31%) . Mean fiber density increased concurrently or earlier from 1.35 to 1.79 (33%) . There were no electrophysiologic signs of presynaptic blockade, even at 2 and 4 weeks . The effects we observed are compatible with stimulation of terminal sprouting by the neurotoxin, without significant presynaptic inhibition of acetylcholine release . We therefore believe that higher dosages of the neurotoxin may be used if clinically indicated. Biochem Biophys Res Commun, 1988 Oct 14, 156(1), 361 - 7 Different types of ADP-ribose protein bonds formed by botulinum C2 toxin, botulinum ADP-ribosyltransferase C3 and pertussis toxin; Aktories K et al.; We attempted to characterize ADP-ribose-amino acid bonds formed by various bacterial toxins . The ADP-ribose-arginine bond formed by botulinum C2 toxin in actin was cleaved with a half-life of about 2 h by treatment with hydroxylamine (0.5 M) . In contrast, the ADP-ribose-cysteine bond formed by pertussis toxin in transducin and the ADP-ribose-amino acid linkage formed by botulinum ADP-ribosyltransferase C3 in platelet cytosolic proteins were not affected by hydroxylamine . HgCl2 cleaved the ADP-ribose-amino acid bond formed by pertussis toxin in transducin but not those formed by botulinum C2 toxin or botulinum ADP-ribosyltransferase C3 in actin and platelet cytosolic proteins, respectively . NaOH (0.5 M) cleaved the ADP-ribose-amino acid bonds formed by botulinum C2 toxin and pertussis toxin but not the one formed by botulinum ADP-ribosyltransferase C3 . The data indicate that the ADP-ribose bond formed by botulinum ADP-ribosyltransferase C3 differs from those formed by the known bacterial ADP-ribosylating toxins. FEBS Lett, 1988 Oct 10, 238(2), 277 - 80 Botulinum toxin-induced ADP-ribosylation and inhibition of exocytosis are unrelated events; Adam-Vizi V et al.; The hypothesis that inhibition of secretion by botulinum neurotoxin type D occurs by an intracellular process involving ADP-ribosylation has been directly tested by measuring both the extent of inhibition of secretion and of ADP-ribosylation in the same cells . Although the inhibitory effect of unpurified toxin closely parallels intracellular ribosylation, the two events are clearly unrelated, as using purified D and C3 toxins together with their antibodies, each of these events can be either stimulated or inhibited independently of each other. J Neurosci, 1988 Oct, 8(10), 3909 - 19 Motor nerve terminal sprouting in formamide-treated inactive amphibian skeletal muscle; Wines MM et al.; Motor axons can form sprouts from their terminal arborizations in response to partial denervation, and when exposed to pharmacological blocking agents like TTX, botulinum toxins alpha-bungarotoxin, or curare . Each of these experimental procedures has cessation of muscle contractile activity as a common feature . We tested the specific role of muscle fiber inactivity in regulating nerve terminal sprouting by chronically treating adult frog (Rana pipiens) cutaneous pectoris muscles with formamide . Exposure to formamide, unlike the other compounds used to study sprouting, selectively inhibits muscle contractions without blocking pre- or postsynaptic transmission or muscle fiber action potentials . Repeated formamide applications were used to achieve chronic block of muscle contractile activity in vivo for up to 6 weeks . Motor axons in formamide-treated inactive muscle sprouted only from their terminal arborizations, but not from nodes of Ranvier . The onset of this sprouting was protracted compared with that seen in pharmacologically blocked mammalian muscles, and sprouts in formamide-treated muscles were more complex and ornate . The frequency of sprouting terminals was less in these formamide-treated muscles than that seen after alternate methods of contractile block, and this suggests that contractile inactivity alone serves as only a moderate cue for sprouting . The possibility is discussed that the prolific sprouting seen following neurotoxin administration may, in fact, be due to perturbations in synaptic transmission or muscle electrical activity rather than muscle fiber inactivity. J Clin Invest, 1988 Oct, 82(4), 1376 - 82 Botulinum C2 toxin ADP-ribosylates actin and enhances O2- production and secretion but inhibits migration of activated human neutrophils; Norgauer J et al.; The binary botulinum C2 toxin ADP-ribosylated the actin of human neutrophils . Treatment of human neutrophils with botulinum C2 toxin for 45 min increased FMLP-stimulated superoxide anion (O2-) production 1.5-5-fold, whereas only a minor fraction of the cellular actin pool (approximately 20%) was ADP-ribosylated . Effects of botulinum C2 toxin depended on toxin concentrations, presence of both components of the toxin, and incubation time . Cytochalasin B similarly enhanced O2- production . The effects of botulinum C2 toxin and cytochalasin B were additive at submaximally, but not maximally effective concentrations and incubation time of either toxin . Botulinum C2 toxin also enhanced stimulation of O2- production by Con A and platelet-activating factor, but not by phorbol 12-myristate 13-acetate (PMA) . Botulinum C2 toxin increased FMLP-induced release of N-acetyl-glucosaminidase by 100-250%; release of vitamin B12-binding protein induced by FMLP and PMA was enhanced by approximately 150 and 50%, respectively . Botulinum C2 toxin blocked both random migration of neutrophils and migration induced by FMLP, complement C5a, leukotriene B4, and a novel monocyte-derived chemotactic agent . The data suggest that botulinum C2 toxin-catalyzed ADP-ribosylation of a minor actin pool has a pronounced effect on the activation of human neutrophils by various stimulants. J Biol Chem, 1988 Sep 25, 263(27), 13739 - 42 ADP-ribosylated actin caps the barbed ends of actin filaments; Wegner A et al.; The mode of action on actin polymerization of skeletal muscle actin ADP-ribosylated on arginine 177 by perfringens iota toxin was investigated . ADP-ribosylated actin decreased the rate of nucleated actin polymerization at substoichiometric ratios of ADP-ribosylated actin to monomeric actin . ADP-ribosylated actin did not tend to copolymerize with actin . Actin filaments were depolymerized by the addition of ADP-ribosylated actin . The maximal monomer concentration reached by addition of ADP-ribosylated actin was similar to the critical concentration of the pointed ends of actin filaments . ADP-ribosylated actin had no effect on the rate of polymerization of gelsolin-capped actin filaments which polymerize at the pointed ends . The results suggest that ADP-ribosylated actin acts as a capping protein which binds to the barbed ends of actin filaments to inhibit polymerization . Based on an analysis of the depolymerizing effect of ADP-ribosylated actin, the equilibrium constant for binding of ADP-ribosylated actin to the barbed ends of actin filaments was determined to be about 10(8) M-1 . As actin is ADP-ribosylated by perfringens iota toxin and by botulinum C2 toxin, it appears that conversion of actin into a capping protein by ADP-ribosylation is a pathophysiological reaction catalyzed by bacterial toxins which ultimately leads to inhibition of actin assembly. FEBS Lett, 1988 Sep 12, 237(1-2), 168 - 72 Gn-proteins are distinct from ras p21 and other known low molecular mass GTP-binding proteins in the platelet; Bhullar RP et al.; The 27 kDa platelet membrane protein (Gn27) that binds {alpha-32P}GTP on nitrocellulose blots of SDS-polyacrylamide gels {(1987) Biochem . J . 245, 617-620} was compared with other low molecular mass GTP-binding proteins . Platelet membranes also contained 21 kDa proteins that bound anti-ras p21 antibody and 22-23 kDa proteins that could be ADP-ribosylated by botulinum neurotoxin type D . These groups of proteins were resolved electrophoretically from each other and from Gn27 . A low molecular mass GTP-binding protein from bovine brain {(1987) Biochem . J . 246, 431-439} was also resolved from Gn27 . At the levels normally present in cell membranes, only Gn-proteins bound significant amounts of {32P}GTP after transfer of protein from SDS-polyacrylamide gels to nitrocellulose. J Chromatogr, 1988 Sep 9, 430(2), 279 - 89 Fast protein liquid chromatography of botulinum neurotoxin types A, B and E; Woody MA et al.; Three antigenically different botulinum neurotoxins (NTs, relative molecular mass approximately 150,000), classically distinguished only by specific antisera, were for the first time chromatographically resolved . Mixed NTs eluted from a Mono-Q column in order of types E, A and B, and from Mono-S as B, E and A . Type A and B NTs were successfully chromatographed on the cation-exchange Mono-S column above their isoelectric points . Purification of type A and B NTs by automated liquid chromatography was also accomplished for the first time . Type A, B and E NTs were purified by application on an anion-exchange Mono-Q column, followed by use of a cation-exchange Mono-S column. Acta Otolaryngol, 1988 Sep-Oct, 106(3-4), 178 - 85 Experimental paralysis of tensor veli palatini muscle; Casselbrant ML et al.; In an effort to study the effects of experimental paralysis of tensor veli palatini (TVP) muscle on Eustachian tube (ET) function and middle-ear (ME) status, botulinum toxin A (Oculinum) was injected into the TVP muscles of 8 Rhesus monkeys . Tubal function was tested longitudinally in 2 animals with tympanostomy tubes using the forced-response test, while in the remaining 6 animals; ME condition was documented daily using tympanometry . The postinjection tubal function was characterized by abolished active muscular function and decreased closing pressure . Activity associated with tubal dilations gradually reappeared by the fifth week . The lack of lumen constrictions following injection suggested that the TVP muscle is the cause of constriction as well as normal dilation . In 6 animals with intact tympanic membranes, 10 of the 12 ears developed flat tympanograms associated with otitis media with effusion (OME) within 8-30 days of injection and serous effusions were recovered by tympanocentesis in seven ears . These results show that a non-traumatic reversible functional obstruction of the ET was created by injecting botulinum toxin A into the TVP muscle . This functional obstruction was associated with the development of high negative ME pressure and serous effusion. Mol Cell Biochem, 1988 Sep, 83(1), 65 - 72 Reductive methylation of lysine residues of botulinum neurotoxin types A and B; Sathyamoorthy V et al.; Reductive methylation of botulinum neurotoxin (NT) serotypes A and B at various ratios of protein to reagent modified up to 75% of the lysine residues . Amino acid analysis of the modified proteins (HCl hydrolysed) confirmed selective modifications of lysine . The derivative N,N-dimethyl lysine was more abundant than monomethyl lysine; trimethyl lysine was not detected . Distribution of modified lysine residues among the heavy and light chains (Mr approximately 100,000 and approximately 50,000, respectively) of the dichain type A NT (Mr approximately 150,000) was approximately proportional to the lysine contents of the two subunit chains of the NT . Toxicity (mouse lethality) and serological reactivity (polyclonal antibody) of serotype A NT were not (or insignificantly) damaged following methylation of up to 72 lysine residues . Modification of 3 additional residues caused precipitous loss in toxicity . Toxicity of serotype B NT, unlike type A, appeared more sensitive to lysine modification . The large number of lysine residues that can be methylated without damaging toxicity of type A NT can be exploited to a) radiolabel the dichain protein exclusively in one chain keeping the other chain unlabelled, b) restrict the number of tryptic cleavage sites of the NT, and c) tag the protein with various markers or reactive ligands. Neurotoxicol Teratol, 1988 Sep-Oct, 10(5), 393 - 416 Effects of neurotoxicants on synaptic transmission: lessons learned from electrophysiological studies; Atchison WD; A number of environmentally-important neurotoxicants affect chemical synaptic transmission in the peripheral and central nervous system . These include heavy metals such as lead, mercury, cadmium and tin; organophosphates; pyrethroid insecticides, and 2,5-hexanedione . Electrophysiological techniques including intracellular microelectrode recording of nerve-evoked and spontaneously occurring synaptic potentials, iontophoresis of neurotransmitter, and voltage clamp of presynaptic and postsynaptic membrane ionic current have proven to be especially useful in analyzing the cellular mechanisms by which these toxicants affect neurotransmission . The process of synaptic transmission can be broadly subdivided into those processes associated with transmitter synthesis, storage and release and sometimes termination of transmitter action (presynaptic processes), and those processes associated with binding of transmitter to its receptors on the receiving cell, activation of the receptor-associated ionic channel and degradation of chemical transmitter (postsynaptic processes) . The processes associated with release of neurotransmitter are the target of a number of naturally-occurring toxins and environmentally important toxicants . General mechanisms by which these agents disrupt presynaptic processes associated with transmission include: prevention or disruption of axonal excitability (pyrethroid insecticides); disruption of calcium-dependent neurotransmitter release (heavy metals, antibiotics, certain snake and spider venom toxins, botulinum toxin); and disruption of intracellular buffering of calcium (heavy metals), Mechanisms by which these agents may disrupt postsynaptic processes include effects on transmitter degradation (organophosphates) or effects on the postsynaptic membrane receptors or associated ionic channels (organophosphates, antibiotics, and perhaps pyrethroids) . Microelectrode studies have shown that cadmium, lead and mercury (organic and inorganic forms) suppress release of neurotransmitter by presynaptic mechanisms and increase spontaneous discharge of transmitter quanta from the presynaptic nerve terminal . This has led to the suggestion that a component of synaptic toxicity of these agents entails block of Ca entry into and buffering by the presynaptic nerve terminals . Conventional and patch voltage clamp studies have been used to measure effects of neurotoxicants on ionic currents carried through voltage-sensitive and receptor-operated ionic channels.(ABSTRACT TRUNCATED AT 400 WORDS) Biochem Biophys Res Commun, 1988 Aug 30, 155(1), 263 - 9 Botulinum toxin D ADP-ribosylates a 22-24 KDa membrane protein in platelets and HL-60 cells that is distinct from p21N-ras; Banga HS et al.; Botulinum toxin D ADP-ribosylates a 22-24 KDa protein in platelets, GH3 and HL-60 cells, and a mouse T-cell line CTLL . In platelet homogenates the protein is localized to the membrane fraction, and ADP-ribosylation can also be produced in saponin-permeabilized and intact cells . In the latter, the toxin also potentiates secretion caused by a variety of agonists . In platelets and HL-60 cells the toxin substrate is shown, by use of anti-ras monoclonal antibody, to be distinct from the ras family of proteins . This toxin substrate may represent an additional class of proteins involved in stimulus-response coupling. Neurology, 1988 Aug, 38(8), 1220 - 5 Effects of botulinum toxin injections on speech in adductor spasmodic dysphonia; Ludlow CL et al.; Adductor spasmodic dysphonia involves an overadduction of the vocal folds during speech causing uncontrolled voice and pitch breaks and slow, effortful speech . The disorder is resistant to speech therapy and often recurs following initial benefit from unilateral recurrent laryngeal nerve resection . Botulinum toxin injections into multiple sites of the thyroarytenoid muscle on one side were performed in 16 patients . Speech was recorded prior to injection and three times post-injection . Symptoms were measured by two examiners from speech spectrograms without knowledge of speaker identity or recording session . Significant (p less than or equal to 0.03) reductions in pitch and voice breaks, phonatory aperiodicity, and sentence time occurred only when injections resulted in unilateral vocal fold paralysis . Symptoms returned with the restoration of vocal fold movement, 3 months later . Reduction in speed of swallowing without aspiration was reported in 80% of cases . Although speech volume was reduced, there were no instances of aphonia. J Neurochem, 1988 Aug, 51(2), 522 - 7 Tetanus toxin and botulinum A and C neurotoxins inhibit noradrenaline release from cultured mouse brain; Habermann E et al.; Primary nerve cell cultures from the brainstem of embryonic mice take up {3H}noradrenaline . Release can be evoked by high K+ or sea anemone toxin II and depends on Ca2+ . The cultures allow neurochemical studies on the long-term actions of clostridial neurotoxins . Tetanus and botulinum A and C neurotoxins partially inhibit the absolute and fractional release evoked by high K+, as well as the fractional basal release . The detection limit for the toxins is below 5 pM . Total radioactivity is higher in the poisoned cultures, although the initial velocity of uptake is not measurably influenced by tetanus or botulinum A toxin . Pretreatment with neuraminidase prevents the effects of botulinum A toxin and diminishes those of botulinum C and tetanus toxins . Within 6 days, the cultures partially recover from tetanus toxin poisoning . Antitoxin prevents the actions of the toxin, but only slightly promotes recovery . The data indicate close pharmacological analogies between the clostridial neurotoxins. Ophthalmology, 1988 Aug, 95(8), 1042 - 5 Hemifacial spasm due to intracranial tumor . An international survey of botulinum toxin investigators; Sprik C et al.; Hemifacial spasm (HFS) due to intracranial mass lesions is rare . Most cases are thought to be due to compression of the facial nerve by small vessels near the root of the facial nerve . A survey was undertaken of all botulinum toxin investigators to determine the incidence of imaged mass lesions causing HFS . Responders contributed information on 1676 patients with HFS . Of this group, nine tumors were reported for an incidence of 0.54% of patients . However, of this group only 52.5% underwent computed tomography (CT) or magnetic resonance (MR) scanning so the incidence of tumor causing HFS could be as high as 1.0% . No one tumor type was predominant, and most patients were women older than 50 years of age . The incidence compares with another large series of HFS patients in which one tumor was found in 367 patients . The authors also report as an illustrative case a 26-year-old man with HFS due to a presumed lipoma of the cerebellopontine angle . This diagnosis can be made with increased certainty with MR scanning . If the incidence of unsuspected diagnostically significant mass lesions is 1 in 200 patients with HFS referred for botulinum toxin injection, the cost of detecting one such lesion would be $100,000 at an average imaging cost of $500 per MR imaging or CT examination . Although mass lesions are uncommon, any patient with HFS whose general clinical course could justify intervention should be considered for imaging studies to rule out treatable conditions other than vascular compression. Ital J Neurol Sci, 1988 Aug, 9(4), 337 - 44 Beneficial effect of botulinum A toxin in blepharospasm: 16 months' experience with 16 cases; Maurri S et al.; After introducing the problem of blepharospasm, we report our experience on treatment with purified botulinum A toxin in 16 cases of blepharospasm, symptomatic in two and essential in 14, than had not responded to drugs . The changes in intensity and frequency of spasm after treatment were evaluated on a clinical scale and by review of videotapes . The beneficial effect appeared within a week in most patients, lasting from 6 to 28 weeks (mean 13), and reached the maximum at the third-seventh week . Mild spasms and female patients responded better . Repeated injections were followed by better response to the drug . Complications, exclusively local, were represented by transient corneal exposure, ptosis, lacrimation or diplopia. Can J Neurol Sci, 1988 Aug, 15(3), 276 - 80 Botulinum toxin injections in the treatment of blepharospasm, hemifacial spasm, and eyelid fasciculations; Kraft SP et al.; Seventy-six patients with blepharospasm (mean age 56.9 years) received 248 injection treatments with botulinum A exotoxin (mean 3.1 treatments per patient): 87.0% of treatments led to total relief of spasms for a mean interval of 14.1 weeks . The average duration of response remained fairly constant over the first six injection series, although patients with the most severe spasms had shorter intervals than patients with less severe symptoms . Twenty patients with hemifacial spasm (mean age 56.9 years) received 44 treatments (mean 1.9 treatments per patient): In 93.1% of cases there was total relief of periocular and perioral spasms, with a mean interval of 17.4 weeks . The average duration of response for the third series of treatments was much shorter than the mean durations for the first two treatments . Side effects were always transient and included ptosis (23.3%), dry eyes (18.1%), tearing (5.5%), and strabismus (1.4%) . No patient had a systemic reaction to the drug . Chronic benign eyelid fasciculations were also successfully treated in 3 patients with single treatments. Am J Ophthalmol, 1988 Jul 15, 106(1), 45 - 7 The effect of omitting botulinum toxin from the lower eyelid in blepharospasm treatment; Frueh BR et al.; We randomly selected 26 patients with essential blepharospasm to receive either botulinum toxin or saline injection in their lower eyelids to evaluate the necessity of lower eyelid injection to relieve blepharospasm . As diplopia may occur from botulinum toxin injections for blepharospasm, most commonly from injection of the lower eyelid, and surgical relief of blepharospasm is often achieved by excision of only the upper eyelid protractors, omission of toxin from the lower eyelid seemed both desirable and possible . All patients received botulinum toxin in the upper eyelids, above the eyebrows, across the glabella, and near the lateral canthus . Thirteen of 15 patients who received saline in their lower eyelids had relief of spasm, with the same spasm-free interval as those who received toxin . We recommend avoiding injection of toxin in the medial two thirds of the lower eyelid in order to diminish the likelihood of diplopia from inferior oblique muscle paresis. J Neurol Neurosurg Psychiatry, 1988 Jul, 51(7), 920 - 3 Botulinum toxin in spasmodic torticollis; Stell R et al.; Ten patients with spasmodic torticollis were treated by injection of a total dose of 30 ng of botulinum toxin type A into the affected sternomastoid and posterior cervical muscles . Nine patients reported improvement in head position and control, which was confirmed in seven cases by clinical assessment and "blind" videotape ratings before and 6 weeks after injection . Five patients who had pain reported relief . Seven patients had mild transient dysphagia after injection; two who were given a more concentrated solution of the toxin developed more severe dysphagia, but this also recovered . Other minor transient side effects included weakness of the voice and local pain . The beneficial effects of botulinum toxin injections lasted some 2 to 3 months . A slight reduction in the total dose of toxin injected avoided the main side effects, and this method of treatment appears to offer successful control of head position and pain in the majority of patients with torticollis. J Neurol Neurosurg Psychiatry, 1988 Jun, 51(6), 767 - 72 Blepharospasm: a review of 264 patients; Grandas F et al.; The natural history and response to different treatments have been evaluated in 264 patients with blepharospasm . The mean age of onset was 55.8 years and there was a female preponderance of 1.8 to 1 . Dystonia elsewhere was found in 78% of patients, usually in the cranial-cervical region, and appeared to follow a somatotopic progression . A family history of blepharospasm or dystonia elsewhere was found in 9.5% of cases, which suggests a genetic predisposition . Ocular lesions preceded the onset of blepharospasm in 12.1% of cases . The response to drugs was inconsistent, although initial improvement was experienced by one fifth of patients treated with anticholinergics . Twenty-nine bilateral facial nerve avulsion operations were performed with benefit in 27 cases; but recurrences appeared in 22, on average one year after surgery . Botulinum toxin injections were performed in 151 patients . Significant improvement was achieved in 118 cases . Mean duration of benefit was 9.2 weeks . Transient ptosis and diplopia were the commonest side effects. Laryngoscope, 1988 Jun, 98(6 Pt 1), 636 - 40 Clinical and laboratory characteristics of focal laryngeal dystonia: study of 110 cases; Blitzer A et al.; Spastic dysphonia is a syndrome often producing a strain-strangle voice . We have previously classified most of these patients as having focal laryngeal dystonia, a disorder of central motor processing . In a study of 1,280 cases of dystonia registered at the Dystonia Clinical Research Center at the Columbia-Presbyterian Medical Center, we found 110 patients who had vocal cord involvement . These patients had historical information evaluated for age of onset (mean 34.6 years), duration of symptoms (mean 13.8 years), sex (1.4:1 female to male) family history (positive in 23%), and primary (66%) and secondary (34%) etiology; neurological evaluation for other dystonic involvement (25% with segmental cranial involvement, 23% with generalized dystonia) or tremor (irregular 23%, regular 6% on EMG) . Treatment options were evaluated and included speech therapy, psychotherapy, biofeedback (with limited success), systemic medication (limited success except in abductor cases), nerve section (with late failure rate), and the use of botulinum toxin (improvement in all 34 injected patients). J Neurochem, 1988 Jun, 50(6), 1808 - 16 Characterization of the inhibitory action of botulinum neurotoxin type A on the release of several transmitters from rat cerebrocortical synaptosomes; Ashton AC et al.; Under optimised conditions for intoxication, botulinum neurotoxin type A was shown to inhibit approximately 90% of Ca2+-dependent K+-evoked release of {3H}acetylcholine, {3H}noradrenaline, and {3H}dopamine from rat cerebrocortical synaptosomes; cholinergic terminals were most susceptible . In each case, the dose-response curve for the neurotoxin was extended, with about 50% of evoked release being inhibited at approximately 10 nM whereas 200 nM was required for the maximal blockade . This may suggest some heterogeneity in the release process . The action of the toxin was time and temperature dependent and appeared to involve binding and sequestration steps prior to blockade of release . The neurotoxin failed to exert any effect on synaptosomal integrity or on Ca2+-independent release of the transmitters tested; it produced only minimal changes in neurotransmitter uptake although small secondary effects were detected with cholinergic terminals . Blockade by the neurotoxin of Ca2+-dependent resting release of transmitter was apparent; Sr2+, Ba2+, or high concentrations of Ca2+ restored the resting release of 3H-catecholamine but not {3H}acetylcholine . Interestingly, none of the latter conditions or 4-aminopyridine could reverse the toxin-induced blockade of evoked release . This lack of specificity in its action on synaptosomes, and other published findings, lead to the conclusion that toxin-sensitive component(s) exist in all nerve terminals that are concerned with transmitter release. J Pharmacol Exp Ther, 1988 Jun, 245(3), 867 - 72 Use of pharmacologic antagonists to deduce commonalities of biologic activity among clostridial neurotoxins; Simpson LL; The pharmacologic activity of several clostridial neurotoxins was assayed on the mouse phrenic nerve-hemidiaphragm preparation . The substances that were assayed included botulinum neurotoxin types A, B, C and E and tetanus toxin . Experiments were done in the presence or absence of antagonists that inhibit either the internalization of toxins or intracellular expression of toxicity . Ammonium chloride and methylamine hydrochloride, agents that inhibit toxins that enter cells by receptor-mediated endocytosis, antagonized botulinum and tetanus neurotoxins . The magnitude of antagonism was substantial for all toxins . Calcium, 3,4-diaminopyridine and guanidine, agents that alter the intracellular expression of toxicity, produced a variable result . They were effective antagonists of botulinum neurotoxin type A, but they were less effective or inactive against the other neurotoxins . The ability of 3,4-diaminopyridine and guanidine to antagonize botulinum neurotoxin type A was highly calcium dependent . When ambient levels of the cation were reduced from 1.8 to 1.0 mM, the activity of the drugs was substantially reduced . The ability of these drugs to produce antagonism was also time dependent . When added simultaneously with toxin, they were maximally active; when added at later times, activity was diminished . A host of agents that alter intracellular levels of cyclic AMP, including theophylline, forskolin, isobutylmethylxanthine and cholera toxin, were evaluated as potential neurotoxin antagonists . Theophylline and isobutylmethylxanthine produced a transient increase in nerve-evoked muscle twitch . None of the drugs that alter tissue levels of cyclic AMP had a universal effect in antagonizing clostridial toxins . The data here have been compared with published data on drugs that antagonize binding of botulinum toxin and tetanus toxin.(ABSTRACT TRUNCATED AT 250 WORDS) Biochem Biophys Res Commun, 1988 May 16, 152(3), 957 - 61 Separation of the 24 kDa substrate for botulinum C3 ADP-ribosyltransferase and the cholera toxin ADP-ribosylation factor; Tsai SC et al.; Botulinum C3 ADP-ribosyltransferase modifies a approximately 24 kDa membrane protein believed to bind guanine nucleotides . Cholera toxin ADP-ribosylation factors are approximately 19 kDa GTP-binding proteins that directly activate the toxin . To evaluate a possible relationship between C3 ADP-ribosyltransferase substrate and ADP-ribosylation factor, they were partially purified from bovine brain . ADP-ribosylation factor, but not C3 ADP-ribosyltransferase substrate, stimulated auto-ADP-ribosylation of the choleragen A1 subunit whereas C3 ADP-ribosyltransferase substrate, but not ADP-ribosylation factor, was ADP-ribosylated by C3 ADP-ribosyltransferase . Thus, although both may be GTP-binding proteins, no functional similarity between ADP-ribosylation factor and C3 ADP-ribosyltransferase substrate was found. FEBS Lett, 1988 May 9, 232(1), 217 - 20 Escherichia coli hemolysin permeabilizes small unilamellar vesicles loaded with calcein by a single-hit mechanism; Menestrina G; Escherichia coli hemolysin produces small unilamellar lipid vesicles permeable to the fluorescent dye calcein by forming pores through their membrane . The process of permeabilization proceeds as a pseudo first-order reaction, indicating that the toxin is active as a monomer; consistently no evidence for cooperativity has been found in a dose-response titration . The rate of interaction increases on lowering the pH of the solution and by introducing negatively charged lipids into the vesicles . The overall pore formation mechanism resembles that of other toxins of bacterial origin such as colicins, diphtheria, tetanus and botulinum toxin. Arch Int Pharmacodyn Ther, 1988 May-Jun, 293, 69 - 83 Cardiac effects of botulinal toxin; Lamanna C et al.; Crystalline type A botulinal toxin rapidly caused temporary bradycardia and electrocardiographic (ECG) changes in mice, rats, rabbits and dogs . In addition, in the dog the force of contraction was measured and found to be depressed . The ECG changes were indicative of conduction defects . The hemagglutinin present in the toxin played no role in the effects on the heart, since a derivative toxin without hemagglutinin also caused these phenomena . The cardiac effects were spontaneously reversible in the intact animal without removal of the toxin . On the other hand, in the in vitro isolated heart of the rat, recovery from the cardiac effects occurred only after the toxin was washed out of the preparation . The findings are consistent with, but do not prove, a physical rather than a chemical mechanism for the effects of toxin on the heart. Br J Ophthalmol, 1988 May, 72(5), 361 - 2 Treatment of senile entropion with botulinum toxin; Clarke JR et al.; Botulinum toxin was used to treat senile entropion in 12 patients by injection into the preseptal orbicularis muscle of the lower lids . It produced relief of symptoms in 10 patients but this was transient, lasting for an average of 14.8 weeks before orbicularis function returned . The technique is simple and easy to perform, and may be useful in selected patients, but surgery offers a more permanent result. Muscle Nerve, 1988 May, 11(5), 493 - 501 Spinal irradiation does not inhibit distal axonal sprouting; Pamphlett RS; In an attempt to determine the relative importance of the nerve cell body and of the axon in initiating and controlling axonal regeneration, nerve cell bodies were irradiated and the ability of the distal axon to sprout was examined . Mice were subjected to either 25 or 50 Gray (Gy) of x-irradiation localized to the lumbar spinal cord . After times varying from 1 day to 6 months after irradiation, a sublethal dose of botulinum toxin (BoTx) was injected into the calf muscles of one leg . The soleus muscle was examined histologically after times varying from 1 week to 6 months after injection, and BoTx-induced ultraterminal axonal sprouting was assessed by the number of motor endplates showing sprouts, the length of the sprouts, and the long term endplate morphology . Apart from some irradiated subgroups having slightly shorter sprout lengths, no significant differences were found between irradiated and nonirradiated groups . The results suggest either that the processes in the nerve cell body responsible for initiating and supporting axonal growth are resistant to large doses of irradiation, or that growth regulatory mechanisms in the distal axon are under local control. J Urol, 1988 May, 139(5), 919 - 22 Effects of botulinum A toxin on detrusor-sphincter dyssynergia in spinal cord injury patients; Dykstra DD et al.; We evaluated the ability of low doses of botulinum A toxin, an inhibitor of acetylcholine release at the neuromuscular junction, to denervate and relax the spastic rhabdosphincter in 11 men with spinal cord injury and detrusor-sphincter dyssynergia . Toxin concentration, injection volume, percutaneous versus cystoscopic injection of the sphincter and number of injections were evaluated in 3 treatment protocols . All 10 patients evaluated by electromyography after injection showed signs of sphincter denervation . Bulbosphincteric reflexes in the 10 patients evaluated after injection were more difficult to obtain, and they showed a decreased amplitude and normal latency . The urethral pressure profile in the 7 patients in whom it was measured before and after treatment decreased an average of 27 cm . water after toxin injections . Post-void residual urine volume decreased by an average of 146 cc after the toxin injections in 8 patients . In the 8 patients for whom it could be determined toxin effects lasted an average of 50 days . The toxin also decreased autonomic dysreflexia in 5 patients. Biochem Biophys Res Commun, 1988 Apr 29, 152(2), 926 - 32 Effect of botulinum D toxin on neutrophils; Mege JL et al.; Activated botulinum D toxin ADP-ribosylates a 22 kDa molecular weight protein in homogenates obtained by sonication of a suspension of rabbit peritoneal neutrophils . The ADP-ribosylation catalyzed by activated botulinum D toxin is inhibited in homogenates obtained from cells pretreated with the toxin, suggesting that it is able to enter into these cells and be activated by them . The rise in intracellular concentration of free calcium in toxin treated cells stimulated by fMet-Leu-Phe is similar to that found in control cells . The basal concentration of intracellular free calcium is significantly elevated in neutrophils treated with the intact but not with the activated form of the botulinum D toxin . Superoxide generation in control and native toxin treated cells stimulated with fMet-leu-Phe, phorbol 12-myristate 13-acetate or opsonized zymosan is the same . The release of beta-glucosaminidase produced by fMet-Leu-Phe or Concanavalin A in botulinum D toxin treated neutrophils was slightly higher than the corresponding release in control cells . Furthermore, the fMet-Leu-Phe-induced increase in the amount of actin associated with the cytoskeleton is not inhibited by botulinum D toxin . These results suggest that the 22 kDa protein which can be ADP-ribosylated by botulinum D toxin is not involved in these stimulated neutrophil responses. Ophthalmology, 1988 Apr, 95(4), 473 - 80 Botulinum toxin A-induced protective ptosis in corneal disease; Kirkness CM et al.; Botulinum toxin A produces a temporary, flaccid ptosis when injected into the levator palpebrae superioris muscle . The resulting protective ptosis was used to aid healing in 21 cases of indolent ulceration, and, prophylactically, in 4 cases of neuroparalytic keratitis . Of the indolent ulcers, 90% healed completely . In all but one case, the cornea was covered completely by the lid and complete ptosis was produced in 75% of cases in an average of 3.6 days, lasting for 16 days on average before recovery began . Recovery of levator function was complete in 8.5 weeks on average . Superior rectus underaction was seen in 68% of cases but this recovered completely in all cases in an average of 6 weeks . Impression cytology showed a trend toward normal conjunctival morphology as healing progressed. Experientia, 1988 Mar 15, 44(3), 224 - 6 Inhibition by tetanus and botulinum A toxin of the release of {3H}noradrenaline and {3H}GABA from rat brain homogenate; Habermann E; Rat brain homogenate was preloaded with {3H}noradrenaline or {3H}GABA and stimulated with high K+ . Tetanus toxin and botulinum A neurotoxin partially prevent the evoked {3H}noradrenaline release in the same range of toxin concentrations starting below 10(-10) M . In contrast, release of gamma-amino butyric acid (GABA) is much more sensitive to tetanus than to botulinum A toxin. Am J Ophthalmol, 1988 Mar 15, 105(3), 313 - 5 Negative antibody response to long-term treatment of facial spasm with botulinum toxin; Gonnering RS; Over a period of 163 weeks, 223 injections of botulinum A toxin were administered to 38 patients with facial spasm syndromes . The maximum cumulative toxin dose was 553 units, the maximum number of injections in any given patient was 16, and the maximum dosage of any given injection was 52.5 units . Sera from these patients showed no antibody production when measured with a standard mouse lethality bioassay. Neurology, 1988 Mar, 38(3), 452 - 8 Spinal cord TRH deficiency is associated with incomplete recovery of denervated muscle in the rat; Van den Bergh P et al.; The raphe-spinal pathway, which contains co-localized serotonin (5-HT), thyrotropin-releasing hormone (TRH), and several TRH-prohormone-derived non-TRH peptides, projects to the ventral horn of the spinal cord . Pharmacologic ablation of this pathway with the 5-HT neurotoxin, 5,7-dihydroxytryptamine, in neonatal rats resulted in deficient recovery of plantar foot muscles, functionally denervated with botulinum toxin type A . Failure of reinnervation was suggested by slower and incomplete recovery of the plantar foot compound muscle action potential amplitude and by a reduced mean diameter of plantar foot muscle fibers in ablated rats . These findings indicate that deprivation of alpha motor neurons from descending raphe-spinal input interferes with their ability to respond to muscle-derived signals for reinnervation. Aust N Z J Ophthalmol, 1988 Feb, 16(1), 15 - 20 Botulinum toxin in ophthalmology; Dunlop D et al.; Alan B . Scott selected, researched and developed Type A Botulinum toxin for clinical use in ophthalmology . This unique drug has proved invaluable for treatment of a number of conditions which are difficult to treat in ophthalmology and in a variety of other disciplines . The indications, methods and problems of its use are described and the results of treatment of 133 patients are discussed . Up to December 1986 over 13,000 patients have been treated in a multicentre international trial without significant complications. Laryngoscope, 1988 Feb, 98(2), 193 - 7 Localized injections of botulinum toxin for the treatment of focal laryngeal dystonia (spastic dysphonia); Blitzer A et al.; Spastic dysphonia is a condition producing a strain-strangle phonation . We have previously classified most of these patients as having focal laryngeal dystonia, a disorder of central motor processing . The initial success of recurrent nerve section in many of these patients has been followed by recurrence of symptoms in months to years . Bilateral involvement of the vocal cords with hyperfunction of the nonparalyzed vocal cord could explain these failures . Injection of botulinum toxin (BOTOX) has been effective treatment for many focal dystonias . We have treated more than 100 patients with dystonia including five with laryngeal dystonia . All of the patients laryngeal had dramatic improvement after 48 to 72 hours; benefit lasted 3 to 9 months for each injection period . BOTOX injection can be performed on awake, ambulatory patients . Bilateral treatment and titration of dose can achieve the desired degree of weakness. J Neurochem, 1988 Feb, 50(2), 431 - 9 Energy metabolism and quantal acetylcholine release: effects of botulinum toxin, 1-fluoro-2,4-dinitrobenzene, and diamide in the Torpedo electric organ; Dunant Y et al.; In the Torpedo electric organ, a modified nerve-muscle system, type A botulinum toxin blocked the release of acetylcholine (ACh) quanta, both neurally evoked and spontaneous . At the same time, the toxin increased the release of a class of small miniature potentials (the subminiature potentials), reduced the ATP and more the creatine phosphate content of the tissue, and impaired the activity of creatine kinase (CK) . Thus, we compared this pattern of changes with those provoked by 1-fluoro-2,4-dinitrobenzene (FDNB), an efficient inhibitor of CK . As expected, FDNB rapidly inactivated CK, which resulted in a profound depletion of ATP whereas the stores of creatine phosphate were preserved . In addition, FDNB caused conspicuous morphological alterations of nerve endings and ACh depletion . This agent also suppressed evoked and spontaneous quantal release whereas the occurrence of subminature potentials was markedly increased . Diamide, a penetrating thiol oxidizing substance, provoked first a transient rise in quantal ACh release and then blockade of transmission with, again, production of a large number of subminiature potentials . Creatine phosphate was depleted in the tissue by diamide, the ATP content reduced, and CK activity partly inhibited . The morphology of nerve terminals did not show obvious changes with either diamide or botulinum toxin at the stage of transmission failure . Although the three poisons acted by different mechanisms, this resulted in a rather similar pattern of physiological changes: failure of quantal release and enhancement of subquantal release . These results and experiments on synaptosomes indicated that CK inhibition was probably a crucial mechanism for FDNB but not for diamide or botulinum intoxication.(ABSTRACT TRUNCATED AT 250 WORDS) Experientia, 1988 Jan 15, 44(1), 18 - 20 Zinc antagonizes the effect of botulinum type A toxin at the mouse neuromuscular junction; Nishimura M et al.; Zn2+ (10-100 microM) elevated the frequency of miniature end-plate potentials (MEPPs) in the mouse diaphragm . The effect did not depend on external Ca2+ . Botulinum type A toxin (BTXA, 50 ng/ml) abolished MEPPs almost completely within 30 min . Zn2+ (100 microM) restored MEPPs and increased their frequency after they had been abolished by BTXA in Ca2+ -free solutions . The antagonistic effect of Zn2+ in the Ca2+ -free solution was reduced by exposing the diaphragm to the toxin in the Ca2+ -free solutions containing high K+ . Thus, the action of BTXA is probably enhanced by depolarization of the motor nerve terminals. J Biol Chem, 1988 Jan 15, 263(2), 696 - 700 Botulinum C2 toxin ADP-ribosylates cytoplasmic beta/gamma-actin in arginine 177; Vandekerckhove J et al.; Isolated cytoplasmic actin of human platelet and pig liver actin, but not rabbit skeletal muscle actin, was ADP-ribosylated by botulinum C2 toxin in the presence of {32P}NAD . Tryptic digestion of the {32P}ADP-ribosylated platelet actin generated two labeled peptides: a soluble peptide covering residues 174-183 and an insoluble fragment containing residues 148-183 . Further digestion of these two peptides with thermolysin yielded the same radioactive peptide, which was in both cases peptide 175-177 . Amino acid sequence analysis of peptides 174-183 and 175-177 located the ADP-ribosylation on Arg177. J Fr Ophtalmol, 1988, 11(3), 237 - 40 {Treatment of blepharospasm and facial hemispasm by injection of botulinum toxin}; Saraux H; 13 patients with hemifacial spasm and 19 patients with blepharospasm (essential blepharospasm or Meige syndrome) were treated with injection of botulinum A toxin in the eyelids . The effectiveness of this therapy is constant and the treatment offers relief to almost all patients . The response times for repeated treatment was 6 months for blepharospasm and 7 months for hemifacial spasm . Repeated injections were performed in several patients and gave the same improvement . Transient ptosis or diplopia were observed in 11 patients . Possible systemic side effects (respiratory trouble) were documented in two patients . Botulinum toxin injection is an effective treatment but the relief is usually temporary and repeated treatments are necessary. Eye, 1988, 2 ( Pt 1), 24 - 8 Botulinum toxin therapy for squint; Lee J et al.; Four hundred and five patients have been treated with injections of Botulinum neurotoxin A to extraocular muscles in the Botulinum Toxin Clinic at Moorfields Eye Hospital from November 1982 until the present . The indications and outcome of therapy are described and discussed. Toxicon, 1988, 26(4), 329 - 36 Tetanus and botulinum toxins block the release of acetylcholine from slices of rat striatum and from the isolated electric organ of Torpedo at different concentrations; Rabasseda X et al.; Tetanus toxin, like botulinum toxin type A, blocks cholinergic synaptic transmission at the central and peripheral nervous systems . Nevertheless, the diseases induced by the two toxins are different since tetanus toxin induces a spastic paralysis and botulinum toxin elicits a flaccid paralysis . Thus, we have investigated the sensitivity of a central and a peripheral cholinergic synapse to these two toxins . We have studied the action of both poison on the release of acetylcholine from slices of the rat striatum and from the isolated electric organ of Torpedo, which is homologous to the neuromuscular junction . Acetylcholine release from the rat striatum was continuously monitored by a chemiluminescent method . The secretion of acetylcholine from the electric organ was estimated both by measuring the amplitude of the evoked electrical discharge from stacks of electroplaques, and by continuously monitoring the neurotransmitter release from isolated nerve terminals . Tetanus toxin blocks the electrical discharge of electric organ prisms, and also impairs the release of acetylcholine from the Torpedo electric organ nerve endings . Our results on acetylcholine release show that tetanus toxin is more potent than botulinum toxin type A at the central cholinergic synapse (tetanus/botulinum toxins potency ratio about 100-200) whereas botulinum toxin is the most potent at the peripheral cholinergic synapse (botulinum/tetanus toxins potency ratio about 100). Graefes Arch Clin Exp Ophthalmol, 1988, 226(2), 141 - 4 Botulinum toxin treatment of acute sixth and third nerve palsy; Metz HS et al.; Thirty-four patients with acute sixth nerve palsy and nine patients with acute third nerve palsy were treated with botulinum toxin injection to the antagonist, nonparalytic horizontal rectus muscle . In a control group of 52 patients with acute sixth nerve palsy not treated with botulinum in the acute stage, only 16 (31%) recovered spontaneously and did not require surgery . Twenty-two of the 31 surviving patients who could be followed with acute sixth nerve palsy had lateral rectus recovery and surgery was avoided . Four required prisms in their glasses to obtain fusion . Nine patients developed chronic sixth nerve palsy and required surgery . In this group of acute sixth nerve palsy patients, eleven were bilateral . Seven of these eleven developed chronic sixth nerve paralysis, and required strabismus surgery . This suggests the prognosis for recovery following botulinum treatment in cases of acute bilateral sixth nerve palsy is not as good as in the unilateral cases . Botulinum toxin treatment does not appear to be effective in chronic sixth nerve palsy, as judged by results of treatment in one patient known to have a chronic palsy . Nine of nine patients with acute third nerve palsy had medial rectus recovery with fusion horizontally in primary gaze . None have required surgery . Only four of nine showed improvement in vertical rotations . The remaining five patients avoid vertical diplopia by a compensatory chin position . Botulinum toxin treatment of patients with acute sixth and third nerve palsy appears beneficial . However, since some in this group of patients may recover spontaneously, a randomized, double-blind study may be necessary to more definitively determine the effectiveness of this therapy. Ann Clin Lab Sci, 1988 Jan-Feb, 18(1), 58 - 71 Bacterial toxins; Lubran MM; Many bacterial toxins are proteins, encoded by the bacterial chromosomal genes, plasmids or phages . Lysogenic phages form part of the chromosome . The toxins are usually liberated from the organism by lysis, but some are shed with outer membrane proteins in outer membrane vesicles . An important non-protein toxin is lipopolysaccharide or endotoxin, which is a constituent of the cell wall of gram negative bacteria . Toxins may damage the eukaryotic cell membrane by combining with some structural component, or otherwise alter its function . Many toxins combine with specific receptors on the surface membrane, frequently glycoproteins or gangliosides, and penetrate the cell to reach their intracellular target . A common mechanism of entry is absorptive endocytosis . Many protein toxins have an A-B structure, B being a polypeptide which binds to the receptor and A being an enzyme . Many toxins are activated, either when produced by the bacterium or when bound to the membrane receptor, by proteases (nicking) . An enzymatic process common to many toxins is adenosine diphosphate (ADP)-ribosylation of the adenylate cyclase regulatory proteins, leading to an increase in intracellular cyclic adenosine monophosphate (cAMP) . This is the mechanism of action of cholera toxin . Diphtheria toxin catalyzes the transfer of ADP-ribose to elongation factor-2, inhibiting protein synthesis . Most toxins act on the target cells to which they bind, but tetanus toxin, and, to a lesser degree, botulinum toxin, ascend axons and affect more distant structures . Although many toxin effects caused by bacteria have been described, only a few toxins have been identified, characterized, and their mode of action determined at the molecular level . The best known of these are discussed. Mov Disord, 1988, 3(4), 333 - 5 Systemic toxicity of botulinum toxin by intramuscular injection in the monkey; Scott AB et al.; Botulinum toxin (Oculinum) was injected intramuscularly into eight monkeys . The LD50 dose is estimated to be approximately 39 U/kg body weight . The lowest dose that caused systemic toxicity, 33 U/kg, was close to the fatal dose range, 38-42 U/kg. Eye, 1988, 2 ( Pt 5), 506 - 16 Monitoring ocular disease by impression cytology; Adams GG et al.; The technique for obtaining and processing conjunctival impression cytology is described . The method of grading the stained samples is outlined . Our findings in various ocular conditions with particular emphasis on; alkali burns, uveitis, hypopyon ulcer and Botulinum toxin protective ptosis are shown . Cytology from severely damaged eyes is highly abnormal, improving as the ocular disease settles . In alkali burns a return to normal cytology does not correlate with return of corneal clarity . Loss of goblet cells is a common finding in the ocular diseases demonstrated, and appears to be a non-specific indicator of ocular problems. Toxicon, 1988, 26(11), 1089 - 94 Mosquito inoculation: an alternative bioassay for toxins; Turell MJ et al.; Mosquitoes were evaluated as a bioassay host for several classes of biological toxins . Mosquitoes were sensitive to snake toxic or neurotoxic phospholipase A2 enzymes (but not to nontoxic phospholipase A2 enzymes), cobrotoxin, saxitoxin, microcystin and the scorpion insect sodium channel toxin . Mosquitoes were not sensitive to ricin, diphtheria toxin, anthrax toxin, botulinum toxin, tetanus toxin, conotoxin G or a scorpion sodium channel toxin toxic to mammals . Specific antisera neutralization tests with mosquitoes gave comparable results to those of a mouse assay . The mosquito is a suitable bioassay animal for many, but not all biological toxins, and offers a safer, more efficient and economical assay than mice. C R Acad Sci III, 1988, 306(15), 483 - 8 {Ganglionic synapses of Aplysia as a model for the study of the mechanism of action of botulinum neurotoxins}; Poulain B et al.; The action of type A and type B botulinum neurotoxin on neurotransmitter release was studied on identified ganglionic synapses of Aplysia . Using this model, we have shown that botulinum neurotoxins at concentrations used in vertebrate preparations had the same specificity of action and that both heavy and light chains of these toxins are intracellularly required to inhibit neurotransmitter release. Zentralbl Bakteriol Mikrobiol Hyg {B}, 1988 Jan, 185(4-5), 368 - 78 {Microbiological research methods of drinking water regulation in West Germany from 1986 . Suitability of the specifications of DIN 38411, Part 7, for the detection of sulfite-reducing, spore-forming anaerobes (Clostridia)}; Schneider J et al.; The drinking-water regulations of the Federal Republic of Germany, from 22.05.1986, contains in paragraph 1 the instructions: "Drinking-water must be free of pathogens", and further in paragraph 11, "Responsibilities of the employer or other owner of a water supplying facility", include that: "The official authority may direct, that the employer...of a water supplying facility has to extend or has to cause to extend the microbiological examinations in order to determine, that...sulfite-reducing, spore-forming anaerobes (Clostridia) can not be detected in 20 ml of water..." The drinking-water regulations do not prescribe a bacteriological examination method in detail . Appendix 1 rules only that the examination for sulfite-reducing, spore-forming anaerobes (Clostridia) has to be performed after heating the sample to 75 degrees C (+/- 5 degrees C) for 10 min, by either the multiple-tube or membrane filtration method and cultivation in DRCM1-medium . If growth occurs, the presence of Clostridia must be confirmed by anaerobic and aerobic subcultivation . Furthermore, a DIN-instruction (DIN 38411, part 7) exists, which prescribes a detailed procedure for multiple-tube and membrane filtration methods, but does not provide for strict anaerobiosis . We were, however, unable to detect Clostridia in a multitude of water samples with the methods of the DIN-regulation . In order to examine if neglect of strict anaerobiosis was the reason for these failures, we checked the suitability of the DIN-regulation for the isolation of Clostridia from drinking water . In preliminary tests we examined up to four strains of the species C . botulinum, C . cadaveris, C . cochlearium, C . difficile, C . innocuum, C . perfringens and C . tertium for their ability to form heat-resistent spores in four sporulation media . It was, however, not possible to find a medium, in which all strains could sporulate within one week . In order to characterize the detection of these anaerobes in water, one particularly well-sporulating strain of each of the following, C . cadaveris, C . difficile and C . perfringens, was selected and the multiple-tube and membrane-filtration methods were compared . Counts of C . difficile and C . perfringens detected by the multiple-tube method were identical with counts of test-suspensions determinded by the most probable number (MPN) method . It was found to be decisive that only freshly prepared DRCM-medium be used and that, disagreeing with the DIN-instruction, cultivation at 37 degrees C is continued for at least four days.(ABSTRACT TRUNCATED AT 400 WORDS) FEBS Lett, 1987 Dec 21, 226(1), 115 - 20 The N-terminal half of the heavy chain of botulinum type A neurotoxin forms channels in planar phospholipid bilayers; Blaustein RO et al.; The heavy chain of botulinum type A neurotoxin forms channels in planar phospholipid bilayer membranes . Channel activity is confined to the N-terminal half of this chain; the C-terminal half is inactive . Channel activity is stimulated by low pH (4.5-5.5) on the cis side (the side to which protein is added), neutral pH on the opposite (trans) side, and cis positive voltages . These findings are strikingly similar to those previously reported for analogous fragments of diphtheria and tetanus toxins. Arch Ophthalmol, 1987 Dec, 105(12), 1703 - 11 Botulinum toxin paralysis of adult monkey extraocular muscle . Structural alterations in orbital, singly innervated muscle fibers; Spencer RF et al.; Botulinum toxin was injected into the medial rectus muscles of adult rhesus monkeys, with postinjection survival periods of three to 56 days . Light and electron microscopic changes were most apparent in the orbital, singly innervated muscle fibers, which during the acute stage (seven to 28 days), exhibited denervationlike hypertrophy with dispersion of the central mitochondria toward the periphery of the fibers . Withdrawal of the capillary network on which this fiber type normally is dependent for oxidative function was a secondary adaptive response to the disuse resulting from botulinum toxin paralysis of neuromuscular transmission . Neuromuscular junctions still were present on all muscle fiber types, although evidence of sprouting was apparent . In the long term (following return of function at 42 to 56 days), the muscle fibers appeared normal and the vasculature recovered in proportion to the decreased cross-sectional area of the muscle fibers. J Biochem (Tokyo), 1987 Dec, 102(6), 1355 - 64 Action of botulinum neurotoxin on acetylcholine release from rat brain synaptosomes: putative internalization of the toxin into synaptosomes; Murayama S et al.; The action of botulinum neurotoxin type C1 on the release of acetylcholine from rat brain synaptosomes was studied by using anti-toxin heavy chain Fab and anti-toxin light chain Fab . The toxin was bound to synaptosomes at 0 degrees C for 10 min, in which {14C}acetylcholine had been accumulated previously . The toxin-binding synaptosomes were pre-incubated at 37 degrees C, and the release of acetylcholine was determined after the synaptosomes had been incubated in 25 mM KCl-incubation medium for 20 min at 37 degrees C . Inhibition of {14C}acetylcholine release from the synaptosomes was observed with increasing pre-incubation time and toxin concentration, and the maximum inhibition was seen after pre-incubation for at least 15 min, which was called the "lag time." The toxin-binding synaptosomes were reacted with anti-toxin heavy chain and anti-toxin light chain Fabs at 0 degrees C for 1.5 min before pre-incubation of the synaptosomes at 37 degrees C . Both Fabs reversed the acetylcholine release inhibition by the toxin . However, when the Fabs were added during the pre-incubation time at 37 degrees C, they showed less restoration with increasing pre-incubation time . The restoration was completely abolished if the Fabs were added to the synaptosomes after the first half of the "lag time." On the other hand, when 125I-labeled toxin-binding synaptosomes were reacted with the Fabs at 0 degrees C for 1.5 min before pre-incubation of the synaptosomes at 37 degrees C, anti-heavy chain Fab removed 125I-toxin from the synaptosomes, but anti-light chain Fab did not . However, if the Fabs were added to toxin-binding synaptosomes during the pre-incubation time at 37 degrees C, the Fabs could not remove 125I-toxin from the synaptosomes, and the synaptosomes retained more labeled toxin with increasing pre-incubation time . These results suggest that there are three distinct steps in the inhibition of acetylcholine release from synaptosomes by botulinum neurotoxin . The first is binding, which is reversible, temperature-independent, and mediated by the heavy chain of the toxin . The second is temperature-dependent internalization, that takes place in the first half of the "lag time," in which both the chains are internalized into synaptosomes . The third is the development of toxicity, which requires the latter half of the "lag time." Scand J Immunol, 1987 Dec, 26(6), 737 - 43 Persistence and selectivity of the immune phagocytosis inhibition by major histocompatibility complex antibodies; Neppert J; Major histocompatibility complex (MHC) antibodies induce immune phagocytosis inhibition (IPI) which lasts for at least 7 days . IPI-inducing antibodies do not inhibit the phagocytosis mediated by the beta-glucan receptor . This corresponds well to recent findings that these antibodies do not interfere with the phagocytosis of deactivated saccharomyces, mediated by the mannose-fucose receptor, or polyacrylic acid particles, also mediated by non-Fc receptors . Substances that interact with certain MHC antigens or with Fc receptors, certain toxins that inhibit surface molecule mobility, and ciclosporin do not cause IPI and do not suppress the induction of IPI by MHC antibodies . These substances are: opioid peptides, insulin, penicillin G, immune complexes, aggregated IgG, Fc fragments, ciclosporin, botulinum C2 toxin, sodium azide . Some lectins and EDTA are inhibitory in a non-selective fashion, since the Fc receptor independent phagocytosis is also abrogated. FEBS Lett, 1987 Nov 16, 224(1), 38 - 42 Botulinum ADP-ribosyltransferase C3 but not botulinum neurotoxins C1 and D ADP-ribosylates low molecular mass GTP-binding proteins; Rosener S et al.; Botulinum ADP-ribosyltransferase C3 modified 21-24 kDa proteins in a guanine nucleotide-dependent manner similar to that described for botulinum neurotoxin C1 and D . Whereas GTP and GTP gamma S stimulated C3-catalyzed ADP-ribosylation in the absence of Mg2+, in the presence of added Mg2+ ADP-ribosylation was impaired by GTP gamma S . C3 was about 1000-fold more potent than botulinum C1 neurotoxin in ADP-ribosylation of the 21-24 kDa protein(s) in human platelet membranes . Antibodies raised against C3 blocked ADP-ribosylation of the 21-24 kDa protein by C3 and neurotoxin C1 but neither cross reacted with neurotoxin C1 immunoblots nor neutralized the toxicity of neurotoxin C1 in mice . The data indicate that the ADP-ribosylation of low molecular mass GTP-binding proteins in various eukaryotic cells is not caused by botulinum neurotoxins but is due to the action of botulinum ADP-ribosyltransferase C3 . The weak enzymatic activities described for botulinum neurotoxins appear to be due to the contamination of C1 and D preparations with ADP-ribosyltransferase C3. Neurosci Lett, 1987 Nov 10, 82(1), 83 - 8 The levator auris longus muscle of the mouse: a convenient preparation for studies of short- and long-term presynaptic effects of drugs or toxins; Angaut-Petit D et al.; We describe here the levator auris longus muscle of the mouse as a convenient neuromuscular preparation for the in vitro study of presynaptic effects of drugs and toxins applied in vivo in young or adult mice . The good visibility of its motor axons and terminals using Nomarski optics allows accurate electrophysiological studies of presynaptic signals . In addition, the levator auris longus muscle is sufficiently thin to be stained as a whole mount preparation . Preliminary results indicate that some correlation can be established between changes in time course of the presynaptic signal and the morphology of motor endings after poisoning the levator auris longus muscle with botulinum type A toxin. Ann Ophthalmol, 1987 Nov, 19(11), 416 - 8, 422 Abducens paralysis repaired with muscle transposition and intraoperative botulinum toxin; Armenia JV et al.; Surgical management of abducens paralysis has been modified frequently since the turn of the century in a continuing effort to produce not only orthotropia in the primary position but good or excellent abduction . We report a bilateral case repaired surgically by a single, whole-muscle, superior rectus transposition . Secondary medial rectus contracture, a common problem, is usually managed by surgical weakening procedures which it is difficult, if not impossible, to grade . We attempted to avoid the problem by weakening the antagonist medial rectus by intraoperative injection of botulinum toxin which might allow a self-adjusting mechanism . Using this approach, fusion in down-gaze without correction and in the primary position with a small amount of vertical and horizontal prism correction was achieved . Good to excellent abduction was restored. Neuroscience, 1987 Nov, 23(2), 767 - 79 Selective location of acceptors for botulinum neurotoxin A in the central and peripheral nervous systems; Black JD et al.; The main site of action for botulinum neurotoxin is cholinergic motor nerve terminals where specific acceptors concentrate the toxin on the cell surface, thereby facilitating its internalization and inactivation of a component essential for transmitter release . In this study, the interaction in vitro of {125I}botulinum neurotoxin type A with central and peripheral nerve terminals of different types was investigated using Ultrofilm and electron-microscope autoradiography . It was found that: (i) The neurotoxin binds to synapse-rich areas of rat brain, particularly in the hippocampus and cerebellum; identity of the neuron types labelled is unclear although cholinergic nerves seem to be labelled, perhaps not exclusively, in many areas . (ii) Toxin uptake at central nerve terminals appears to be minimal and its penetration into intact brain slices is restricted; this may account for the toxin's lower central toxicity . (iii) Selective labelling of cholinergic nerves but not purinergic, peptidergic or adrenergic nerve terminals in mouse ileum suggests that the toxin may be a specific marker for cholinergic nerves in the periphery . Based on these localization studies and published pharmacological observations, it is concluded that efficient toxin-induced blockade of neurotransmission depends on the presence of specific acceptors of high affinity for the toxin and of an effective neuronal uptake mechanism . Inhibition of the release of numerous transmitters from different kinds of nerve terminals lacking one of these features can be produced by high toxin concentrations when uptake occurs via low affinity acceptors or by non-specific means . Notably, this widespread action of the toxin indicates the occurrence of a common intracellular target in several, possibly all, nerve types. Br J Ophthalmol, 1987 Sep, 71(9), 664 - 8 Long-term results of treatment of idiopathic blepharospasm with botulinum toxin injections; Elston JS; One hundred and one patients with idiopathic blepharospasm have been treated with injections of botulinum toxin A into the orbicularis oculi . Ten had previously had facial nerve avulsions and responded well, normal visual function being restored in the majority (7/10) for an average of 14 weeks . Without prior surgical treatment the response was more variable, but 71/91 regained normal or near normal vision . Older patients, those with a family history of the condition, and those without oromandibular dystonia responded slightly better . The severity of the blepharospasm, the length of the history, and spontaneous resolution of an episode of focal dystonia in the past had no influence on the outcome . Results were poor in the presence of an associated neurological disorder . Side effects, particularly a temporary partial ptosis, were common but were well tolerated . The average duration of improvement was eight weeks in men, nine in women, and there was no evidence of any increase in duration after multiple injections . Eighty nine patients continued with injections, 11 opted for surgical treatment, and one resumed drugs. Arch Ophthalmol, 1987 Sep, 105(9), 1265 - 8 Experimental doxorubicin myopathy . A permanent treatment for eyelid spasms? Baker L, Wirtschafter JD. Doxorubicin may effect a more permanent chemomyectomy and chemodenervation (by retrograde "suicide transport") of the orbicularis oculi muscle than the chemodenervation produced by botulinum A toxin used for the treatment of blepharospasm . Graded doses (0.4 mg and 1.0 mg) of doxorubicin hydrochloride (2 mg/mL) were injected into the eyelids and antecubital and popliteal skin of rabbits in an attempt to evaluate the drug's efficacy and safety . Histologic changes in the orbicularis oculi muscle included necrosis and decreased mass . The results are promising because the eyelids appear to be more resistant than other skin regions to the development of tissue necrosis . Moreover, doxorubicin might not be excessively toxic in the treatment of eyelid cancer. Ann Otol Rhinol Laryngol, 1987 Sep-Oct, 96(5), 534 - 41 Use of botulinum toxin to lateralize true vocal cords: a biochemical method to relieve bilateral abductor vocal cord paralysis; Cohen SR et al.; Using the mong