Pyridostigmine ameliorates pristane-induced arthritis symptoms in Dark Agouti rats.

OBJECTIVE: Rheumatoid arthritis (RA) is a chronic inflammatory disorder. Pyridostigmine (PYR), an acetylcholinesterase (AChE) inhibitor, has been shown to reduce inflammation and oxidative stress in several animal models for inflammation-associated conditions. The present study aimed to investigate the effects of PYR on pristane-induced (PIA) in Dark Agouti (DA) rats. METHOD: DA rats were intradermally infused with pristane to establish the PIA model, which was treated with PYR (10 mg/kg/day) for 27 days. The effects of PYR on synovial inflammation, oxidative stress, and gut microbiota were evaluated by determining arthritis scores, H&E staining, quantitative polymerase chain reaction, and biochemical assays, as well as 16S rDNA sequencing. RESULTS: Pristane induced arthritis, with swollen paws and body weight loss, increased arthritis scores, synovium hyperplasia, and bone or cartilage erosion. The expression of pro-inflammatory cytokines in synovium was higher in the PIA group than in the control group. PIA rats also displayed elevated levels of malondialdehyde, nitric oxide, superoxide dismutase, and catalase in plasma. Moreover, sequencing results showed that the richness, diversity, and composition of the gut microbiota dramatically changed in PIA rats. PYR abolished pristane-induced inflammation and oxidative stress, and corrected the gut microbiota dysbiosis. CONCLUSION: The results of this study support the protective role of PYR in PIA in DA rats, associated with the attenuation of inflammation and correction of gut microbiota dysbiosis. These findings open new perspectives for pharmacological interventions in animal models of RA.

Effect of treatment with Fufang Huangqi decoction on dose reductions and discontinuation of pyridostigmine bromide tablets, prednisone, and tacrolimus in patients with type I or II myasthenia gravis.

OBJECTIVE: To investigate the clinical efficacy of Fufang Huangqi decoction in combination with pyridostigmine bromide tablets, prednisone, and tacrolimus in the treatment of type I and II myasthenia gravis (MG) through changes in the clinical symptom scores of 100 patients with type I and II MG. This study also aimed to examine dose reductions and dis-continuation of these 3 Western medicines after administration of Fufang Huangqi decoction. METHODS: The clinical data on 100 patients with type I or II MG who were treated in the outpatient department of the Affiliated Hospital of Liaoning University of Traditional Chinese Medicine, China, between June 2017 and June 2020 were collected. The patients were divided into 4 groups based on whether they had taken pyridostigmine bromide tablets, prednisone, and/or tacrolimus at the time of their hospital visit: the Fufang Huangqi decoction group (group A), the pyridostigmine bromide tablets + Fufang Huangqi decoction group (group B), the pyridostigmine bromide tablets + prednisone + Fufang Huangqi decoction group (group C), and the pyridostigmine bromide tablets + tacrolimus + Fufang Huangqi decoction group (group D). The average treatment time was (15.6 ± 11.5) months (range: 0.5-55 months). Changes in the clinical symptom scores of the 4 groups of patients after medication administration and dose reductions and discontinuation of the 3 Western medicines were analyzed. RESULTS: An overall effectiveness rate of 86.00% was achieved in the 100 patients after treatment for (15.6 ± 11.5) months (range 0.5-55 months). The effectiveness rates were 85.71% in group A, 88.24% in group B, 76.92% in group C, and 80.00% in group D. The dosage of pyridostigmine bromide was reduced for 69.12% of the patients in group B for the first time after (4.2 ± 4.1) months, and 45.59% of the patients in group B discontinued pyridostigmine bromide after (8.8 ± 6.1) months. The dosage of pyridostigmine bromide was reduced for 46.15% of the patients in group C for the first time after (5.3 ± 3.4) months, and 23.08% of the patients in group C discontinued pyridostigmine bromide after (19.8 ± 11.0) months; 76.92% reduced hormone dosage after (2.8 ± 1.9) months, and 23.08% discontinued hormone treatment after (6.7 ± 2.9) months. The dosage of pyridostigmine bromide was reduced for 1 patient in group D after 1 month; this patient discontinued pyridostigmine bromide after 3 months and reduced tacrolimus dosage after 5 months. One patient in group D discontinued pyridostigmine bromide and tacrolimus on his own initiative at 0.5 months and took Fufang Huangqi decoction for 2 months without discontinuing Western medicine. CONCLUSION: Fufang Huangqi decoction is effective for the treatment of type I and II MG and improves the associated clinical symptoms. Moreover, this agent is conducive to dose reductions and discontinuation of basic Western medicines, thereby reducing the side effects experienced by patients.

Epidemiological profile of myasthenia gravis in South Korea using the national health insurance database.

OBJECTIVES: Myasthenia gravis (MG) is an autoimmune disease characterized by muscle weakness and fatigue. Our objective was to investigate the incidence of MG using the National Health Insurance database of South Korea. MATERIALS AND METHODS: We conducted a retrospective cohort analysis of patients with the G70.0 code designated as MG and administered with MG medications for >3 months from 2007 to 2018 using nationwide data from South Korea. RESULTS: A total of 8,376 patients with MG during the period of 2010-2018 were identified. There were 3,862 (46.1%) male and 4,517 (53.9%) female patients. The standardized incidence rate was 1.18/100,000 in 2010, and increased to 1.81/100,000 in 2018. The standardized prevalence was 7.50/100,000 in 2010, and changed to 11.15/100,000 in 2018. Pyridostigmine was used to treat 82.3 ± 1.2% of patients with MG during 2010-2018. Among MG patients, 85.7 ± 0.9% used steroids, 31.6 ± 4.8% used azathioprine, 12.9 ± 9.5% used tacrolimus, 7.2 ± 2.1% used cyclosporine, 6.2 ± 1.8% used mycophenolate mofetil, and 0.4 ± 0.1% used methotrexate. Thymectomy was performed in 1,130 MG patients, and the time from MG diagnosis to thymectomy decreased from 2010 to 2018. CONCLUSION: Based on the national registry data from 2010 to 2018, the incidence and prevalence rate in South Korea has increased. Whereas the use of IVIG has remained stable, thymectomy is performed earlier than before, and the distribution of immunosuppressant therapies has changed over the years with an increase in tacrolimus and mycophenolate mofetil. We expect that this study will serve as a basis for future South Korean MG epidemiological studies.

Enhancing GABAergic Transmission Improves Locomotion in a Caenorhabditis elegans Model of Spinal Muscular Atrophy.

Spinal muscular atrophy (SMA) is a neuromuscular disease characterized by degeneration of spinal motor neurons resulting in variable degrees of muscular wasting and weakness. It is caused by a loss-of-function mutation in the survival motor neuron (SMN1) gene. Caenorhabditis elegans mutants lacking SMN recapitulate several aspects of the disease including impaired movement and shorted life span. We examined whether genes previously implicated in life span extension conferred benefits to C. elegans lacking SMN. We find that reducing daf-2/insulin receptor signaling activity promotes survival and improves locomotor behavior in this C. elegans model of SMA. The locomotor dysfunction in C. elegans lacking SMN correlated with structural and functional abnormalities in GABAergic neuromuscular junctions (NMJs). Moreover, we demonstrated that reduction in daf-2 signaling reversed these abnormalities. Remarkably, enhancing GABAergic neurotransmission alone was able to correct the locomotor dysfunction. Our work indicated that an imbalance of excitatory/inhibitory activity within motor circuits and underlies motor system dysfunction in this SMA model. Interventions aimed at restoring the balance of excitatory/inhibitory activity in motor circuits could be of benefit to individuals with SMA.

Flaccid paralysis in an infant associated with a dirty wound and application of honey.

An infant, who was born preterm at 36 weeks, presented with fever and ulcer at umbilical region which progressed to necrotising fasciitis of anterior abdominal wall. He was treated with intravenous penicillin, intravenous cloxacillin and local application of medicated honey. Subsequently, he required wound debridement. Postoperatively, he required prolonged invasive ventilation due to poor respiratory effort which was associated with hypotonia and areflexia. Nerve conduction study revealed absent responses. The diagnosis of infant botulism was made based on the clinical presentation, nerve conduction study and his clinical progress. Botulinum immunoglobulin was not available. He was treated with intravenous immunoglobulin and oral pyridostigmine. He was successfully extubated after 37 days, and currently the patient is doing well.

Time Course, Behavioral Safety, and Protective Efficacy of Centrally Active Reversible Acetylcholinesterase Inhibitors in Cynomolgus Macaques.

Galantamine hydrobromide and (-)huperzine A, centrally active reversible acetylcholinesterase inhibitors, are potentially superior to the current standard, pyridostigmine bromide, as a pretreatment for organophosphorus chemical warfare nerve agent intoxication. Galantamine, huperzine, and pyridostigmine were compared for time course of acetylcholinesterase inhibition in 12 cynomolgus macaques. Although both galantamine and huperzine shared a similar time course profile for acetylcholinesterase inhibition, huperzine was 88 times more potent than galantamine. The dose for 50% acetylcholinesterase inhibition (ID50) was 4.1 ug/kg for huperzine, 362 ug/kg for galantamine, and 30.9 ug/kg for pyridostigmine. In a safety assessment, galantamine, huperzine, and pyridostigmine were examined using an operant time-estimation task. Huperzine and pyridostigmine were devoid of behavioral toxicity, whereas galantamine was behaviorally toxic at doses producing peak acetylcholinesterase inhibition of about 50% and higher. Following pretreatment with galantamine, huperzine or pyridostigmine, monkeys were challenged with the median lethal dose of soman at the time of peak acetylcholinesterase inhibition and evaluated for overt signs of soman toxicity (cholinergic crisis, convulsions). Both huperzine and galantamine were equally effective at preventing overt signs of soman toxicity, but neither drug was capable of preventing soman-induced neurobehavioral disruption. In contrast, three of four pyridostigmine-pretreated animals exposed to soman exhibited convulsions and required therapy. Full functional recovery required 3-16 days. The degree of acetylcholinesterase inhibition was lower for pyridostigmine, but rates of recovery of acetylcholinesterase activity following soman challenge were comparable for all drug pretreatments. Huperzine may be the more promising centrally active reversible acetylcholinesterase inhibitor due to its greater potency and superior safety profile.

Improving vagal activity ameliorates cardiac fibrosis induced by angiotensin II: in vivo and in vitro.

Cardiac remodeling is characterized by overactivity of the renin-angiotensin system (RAS) and withdrawal of vagal activity. We hypothesized that improving vagal activity could attenuate cardiac fibrosis induced by angiotensin II (Ang II) in vivo and in vitro. Rats were subjected to abdominal aorta constriction (AAC) with or without pyridostigmine (PYR) (31 mg/kg/d). After 8 weeks, PYR significantly decreased Ang II level, AT1 protein expression, and collagen deposition in cardiac tissue and improved heart rate variability, baroreflex sensitivity and cardiac function, which were abolished by atropine. In vitro, treatment of cardiac fibroblasts (CFs) with Ang II (10(-7) M) increased cell proliferation, migration, transformation, and secretory properties, which were significantly diminished by acetylcholine (ACh, 10(-6) M). Subsequently, Ang II significantly increased collagen type I expression as well as metalloproteinase (MMP)-2 expression and activity. Transforming growth factor (TGF)-ß1 expression and Smad3 phosphorylation presented a similar trend. Notably, the knockdown of the acetylcholine M2 receptor by siRNA could abolish ACh anti-fibrotic action. These data implicated cholinesterase inhibitor can increase vagal activity and reduce local Ang II level, and ACh inhibit Ang II pro-fibrotic effects. Our findings suggested that the parasympathetic nervous system can serve as a promising target for cardiac remodeling treatment.

Acetylcholinesterase Inhibition Attenuates the Development of Hypertension and Inflammation in Spontaneously Hypertensive Rats.

BACKGROUND: It is hypothesized that chronic increase of availability of acetylcholine, resulting from the effect of antiacetylcholinesterases, may prevent autonomic imbalance and reduce inflammation yielding benefic effects for cardiovascular disorders in hypertension. The effect of long-term administration of antiacetylcholinesterase agents with central and/or peripheral action, i.e., donepezil and pyridostigmine, were investigated on arterial pressure (AP), sympathovagal balance, plasma cytokine levels, and cardiac remodeling in spontaneously hypertensive rats (SHR). METHODS: Chronic treatment with donepezil or pyridostigmine started before the onset of hypertension. AP was measured by plethysmography every 4 weeks. At the end of 16 weeks of treatment, methylatropine was used to evaluate the cardiac vagal tone; AP and pulse interval (PI) variability were also evaluated followed by plasma and heart collection for analysis. RESULTS: Pyridostigmine, which does not cross the blood-brain barrier, increased cardiac vagal tone, and reduced cardiomyocyte diameter and collagen density, but did not affect the AP and plasma cytokine levels. Donepezil, which crosses the blood-brain barrier, attenuated the development of hypertension, increased cardiac vagal tone, and improved AP and PI variability. Likewise, donepezil reduced the plasma levels of tumor necrosis factor-α, interleukin 6, and interferon γ, besides reducing cardiomyocyte diameter and collagen density. CONCLUSIONS: Donepezil attenuated the development of hypertension in SHR probably involving antiinflammatory effects, indicating that acetylcholinesterase inhibition yields benefic effects for antihypertensive therapy.

Pyridostigmine restores cardiac autonomic balance after small myocardial infarction in mice.

The effect of pyridostigmine (PYR)--an acetylcholinesterase inhibitor--on hemodynamics and cardiac autonomic control, was never studied in conscious myocardial infarcted mice. Telemetry transmitters were implanted into the carotid artery under isoflurane anesthesia. Seven to ten days after recovery from the surgery, basal arterial pressure and heart rate were recorded, while parasympathetic and sympathetic tone (ΔHR) was evaluated by means of methyl atropine and propranolol. After the basal hemodynamic recording the mice were subjected to left coronary artery ligation for producing myocardial infarction (MI), or sham operation, and implantation of minipumps filled with PYR or saline. Separate groups of anesthetized (isoflurane) mice previously (4 weeks) subjected to MI, or sham coronary artery ligation, were submitted to cardiac function examination. The mice exhibited an infarct length of approximately 12%, no change in arterial pressure and increased heart rate only in the 1st week after MI. Vagal tone decreased in the 1st week, while the sympathetic tone was increased in the 1st and 4th week after MI. PYR prevented the increase in heart rate but did not affect the arterial pressure. Moreover, PYR prevented the increase in sympathetic tone throughout the 4 weeks. Concerning the parasympathetic tone, PYR not only impaired its attenuation in the 1st week, but enhanced it in the 4th week. MI decreased ejection fraction and increased diastolic and systolic volume. Therefore, the pharmacological increase of peripheral acetylcholine availability by means of PYR prevented tachycardia, increased parasympathetic and decreased sympathetic tone after MI in mice.

Gulf War syndrome as a part of the autoimmune (autoinflammatory) syndrome induced by adjuvant (ASIA).

Gulf War syndrome (GWS) is a multi-symptom condition comprising a variety of signs and symptoms described in the literature, which not been fully resolved. The various symptoms of the condition include muscle fatigue and tiredness, malaise, myalgia, impaired cognition, ataxia, diarrhoea, bladder dysfunction, sweating disturbances, headaches, fever, arthralgia, skin rashes, and gastrointestinal and sleep disturbances. In addition, excessive chemical sensitivity and odour intolerance is reported. The aetiology of the condition is unclear, but many reviews and epidemiological analyses suggest association with pyridostigmine bromide (PB), certain vaccination regimes, a variety of possible chemical exposures, including smoke from oil-well fires or depleted uranium from shells, as well as physical and psychological stress. Recently, Shoenfeld et al. suggested that four conditions--siliconosis, macrophagic myofaciitis (MMF), GWS and post-vaccination phenomena--that share clinical and pathogenic resemblances, may be incorporated into common syndrome called 'Autoimmune (Autoinflammatory) Syndrome induced by Adjuvants' (ASIA). Symptoms and signs of the four conditions described by Shoenfeld et al. show that at least eight out of ten main symptoms are in correlation in all four conditions. Namely, myalgia, arthralgias, chronic fatigue, neurological cognitive impairment, gastrointestinal symptoms, respiratory symptoms, skin manifestations and appearance of autoantibodies. Regardless of the aetiology of GWS, be it exposure to environmental factors or chemical drugs, vaccinations or the adjuvants in them, GWS fits well with the definition of ASIA and is included as part of 'Shoenfeld's syndrome'.

[+]-Huperzine A protects against soman toxicity in guinea pigs.

The chemical warfare nerve agent (CWNA) soman irreversibly inhibits acetylcholinesterase (AChE) causing seizure, neuropathology and neurobehavioral deficits. Pyridostigmine bromide (PB), the currently approved pretreatment for soman, is a reversible AChE inhibitor that does not cross the blood-brain barrier (BBB) to protect against central nervous system damage. [-]-Huperzine A, a natural reversible AChE inhibitor, rapidly passes through the BBB and has numerous neuroprotective properties that are beneficial for protection against soman. However, [-]-Huperzine A is toxic at higher doses due to potent AChE inhibition which limits the utilization of its neuroprotective properties. [+]-Huperzine A, a synthetic stereoisomer of [-]-Huperzine A and a weak inhibitor of AChE, is non-toxic. In this study, we evaluated the efficacy of [+]-Huperzine A for protection against soman toxicity in guinea pigs. Pretreatments with [+]-Huperzine A, i.m., significantly increased the survival rate in a dose-dependent manner against 1.2× LD(50) soman exposures. Behavioral signs of soman toxicity were significantly reduced in 20 and 40 mg/kg [+]-Huperzine A treated animals at 4 and 24 h compared to vehicle and PB controls. Electroencephalogram (EEG) power spectral analysis showed that [+]-Huperzine A significantly reduces soman-induced seizure compared to PB. [+]-Huperzine A (40 mg/kg) preserved higher blood and brain AChE activity compared to PB in soman exposed animals. These data suggest that [+]-Huperzine A protects against soman toxicity stronger than PB and warrant further development as a potent medical countermeasure against CWNA poisoning.

In vitro kinetic interactions of pyridostigmine, physostigmine and soman with erythrocyte and muscle acetylcholinesterase from different species.

The low effectiveness of atropine and oxime treatment in soman poisoning may be enhanced by carbamates pre-treatment. For ethical reasons medical countermeasures can only be tested in animal models despite the fact of substantial species differences. With this kinetic in vitro study the interactions between pyridostigmine, physostigmine and soman with human, Rhesus monkey, swine and guinea pig erythrocyte AChE were investigated. In addition, the effect of the carbamates on the residual activity and enzyme recovery after soman inhibition was examined with erythrocyte and intercostal muscle AChE from these species with a dynamic in vitro model with real-time determination of AChE activity. Only small to moderate species differences of the inhibition and decarbamylation kinetics were recorded. It was possible to show that with erythrocyte and muscle AChE a similar level of protection by carbamates and reactivation after discontinuation of the carbamates and soman could be observed. Thus, these data indicate that carbamate pre-treatment is expected to protect a critical level of muscle AChE and confirm the presumption that erythrocyte AChE may serve as a surrogate for synaptic AChE. Hence, these and previous data fortify the notion that erythrocyte AChE is a proper tool for in vitro kinetic studies as well as for therapeutic monitoring in experimental and clinical studies.

Protection by pyridostigmine bromide of marmoset hemi-diaphragm acetylcholinesterase activity after soman exposure.

Pyridostigmine bromide (PB) was approved by the U.S. Food and Drug Administration (FDA) in 2003 as a pretreatment in humans against the lethal effects of the irreversible nerve agent soman (GD). Organophosphate (OP) chemical warfare agents such as GD exert their toxic effects by inhibiting acetylcholinesterase (AChE) from terminating the action of acetylcholine at postsynaptic sites in cholinergic nerve terminals (including crucial peripheral muscle such as diaphragm). As part of the post-marketing approval of PB, the FDA required (under 21CFR314, the "two animal rule") the study of a non-human primate model (the common marmoset Callithrix jacchus jacchus) to demonstrate increased survival against lethal GD poisoning, and protection of physiological hemi-diaphragm function after PB pretreatment and subsequent GD exposure. Marmosets (male and female) were placed in the following experimental groups: (i) control (saline pretreatment only), (ii) low dose PB (12.5 microg/kg), or (iii) high dose (39.5 microg/kg) PB. Thirty minutes after the PB dose, animals were challenged with either saline (control) or soman (GD, 45 microg/kg), followed 1 min later by atropine (2mg/kg) and 2-PAM (25mg/kg). After a further 16 min, animals were euthanized and the complete diaphragm removed; the right hemi-diaphragm was frozen immediately at -80 degrees C, and the left hemi-diaphragm was placed in a tissue bath for 4h (to allow for decarbamylation to occur), then frozen. AChE activities were determined using the automated WRAIR cholinesterase assay. Blood samples were collected for AChE activities prior to PB, before GD challenge, and after sacrifice. RBC-AChE was inhibited by approximately 18% and 50% at the low and high doses of PB, respectively, compared to control (baseline) activity. In the absence of PB pretreatment, the inhibition of RBC-AChE by GD was 98%. The recovery of hemi-diaphragm AChE activity after the 4h wash period (decarbamylation) was approximately 8% and 17%, at the low and high PB doses, respectively, compared with the baseline (control) AChE activity prior to PB pretreatment or soman exposure. The results suggest that PB pretreatment protects a critical fraction of AChE activity in the marmoset diaphragm, which is sufficient to allow the animal to breathe despite exposure to a dose of soman that is lethal in unprotected animals.

Acute electrophysiologic consequences of pyridostigmine inhibition of cholinesterase in humans

The cardiovascular electrophysiologic basis for the action of pyridostigmine, an acetylcholinesterase inhibitor, has not been investigated. The objective of the present study was to determine the cardiac electrophysiologic effects of a single dose of pyridostigmine bromide in an open-label, quasi-experimental protocol. Fifteen patients who had been indicated for diagnostic cardiac electrophysiologic study underwent two studies just before and 90-120 min after the oral administration of pyridostigmine (45 mg). Pyridostigmine was well tolerated by all patients. Wenckebach nodal anterograde atrioventricular point and basic cycle were not altered by pyridostigmine. Sinus recovery time (ms) was shorter during a 500-ms cycle stimulation (pre: 326 ± 45 vs post: 235 ± 47; P = 0.003) but not during 400-ms (pre: 275 ± 28 vs post: 248 ± 32; P = 0.490) or 600-ms (pre: 252 ± 42 vs post: 179 ± 26; P = 0.080) cycle stimulation. Pyridostigmine increased the ventricular refractory period (ms) during the 400-ms cycle stimulation (pre: 238 ± 7 vs post: 245 ± 9; P = 0.028) but not during the 500-ms (pre: 248 ± 7 vs post: 253 ± 9; P = 0.150) or 600-ms (pre: 254 ± 8 vs post: 259 ± 8; P = 0.255) cycle stimulation. We conclude that pyridostigmine did not produce conduction disturbances and, indeed, increased the ventricular refractory period at higher heart rates. While the effect explains previous results showing the anti-arrhythmic action of pyridostigmine, the clinical impact on long-term outcomes requires further investigation.

Acute electrophysiologic consequences of pyridostigmine inhibition of cholinesterase in humans.

The cardiovascular electrophysiologic basis for the action of pyridostigmine, an acetylcholinesterase inhibitor, has not been investigated. The objective of the present study was to determine the cardiac electrophysiologic effects of a single dose of pyridostigmine bromide in an open-label, quasi-experimental protocol. Fifteen patients who had been indicated for diagnostic cardiac electrophysiologic study underwent two studies just before and 90-120 min after the oral administration of pyridostigmine (45 mg). Pyridostigmine was well tolerated by all patients. Wenckebach nodal anterograde atrioventricular point and basic cycle were not altered by pyridostigmine. Sinus recovery time (ms) was shorter during a 500-ms cycle stimulation (pre: 326 +/- 45 vs post: 235 +/- 47; P = 0.003) but not during 400-ms (pre: 275 +/- 28 vs post: 248 +/- 32; P = 0.490) or 600-ms (pre: 252 +/- 42 vs post: 179 +/- 26; P = 0.080) cycle stimulation. Pyridostigmine increased the ventricular refractory period (ms) during the 400-ms cycle stimulation (pre: 238 +/- 7 vs post: 245 +/- 9; P = 0.028) but not during the 500-ms (pre: 248 +/- 7 vs post: 253 +/- 9; P = 0.150) or 600-ms (pre: 254 +/- 8 vs post: 259 +/- 8; P = 0.255) cycle stimulation. We conclude that pyridostigmine did not produce conduction disturbances and, indeed, increased the ventricular refractory period at higher heart rates. While the effect explains previous results showing the anti-arrhythmic action of pyridostigmine, the clinical impact on long-term outcomes requires further investigation.

Reversal of rocuronium-induced neuromuscular blockade by pyridostigmine in patients with Duchenne muscular dystrophy.

BACKGROUND: The aim of this study was to investigate the effect and safety of pyridostigmine for the reversal of a neuromuscular block (NMB) in patients with Duchenne muscular dystrophy (DMD). In patients with DMD recovery from a rocuronium-induced NMB is markedly delayed. METHODS: Fourteen DMD patients (aged between 11 and 19 years) scheduled for elective scoliosis repair were studied. Following tracheal intubation without muscle relaxant, all patients received a single dose of rocuronium 0.6 mg.kg(-1). NMB was monitored by acceleromyography at the adductor pollicis muscle. When the first twitch height (T1) of the train-of-four (TOF) had recovered to 25% seven patients received either pyridostigmine 0.1 mg.kg(-1) (the anticholinergic drug with a long duration of action) or saline in a blinded manner. The times to attain TOF ratio of 0.9 were recorded. For comparison the Mann-Whitney U-test was used. RESULTS: Recovery to TOF ratio of 0.9 was significantly (P < 0.05) accelerated by pyridostigmine [84 (median), 57-141(range)] compared with controls (148, 84-243 min). The recovery time (time between T1 of 25% and TOF of 90%) was also significantly (P < 0.01) shortened by pyridostigmine (15, 8-49 vs 76, 43-144 min, respectively). Time to recovery of T(1) to 90% was not different between the groups (108, 63-134 vs 169. 61-208 min, respectively). CONCLUSIONS: Pyridostigmine 0.1 mg.kg(-1) effectively reversed a rocuronium-induced NMB in DMD patients.

[Electroacupuncture warming therapy combined with western medicine for treatment of myasthenia gravis and effect on IL-4 level in the patients].

OBJECTIVE: To observe the therapeutic effect of electroacupuncture (EA) warming therapy on myasthenia gravis (MG) and effect on IL-4 in the patient. METHODS: Sixty patients with MG were randomly divided into two groups, 30 patients in each group. The observation group were treated with EA warming therapy with Tanzhong (CV 17), Shimen (CV 5), Guanyuan (CV 4), Zhongwan (CV 12), Yanglingquan (GB 34) selected as main points, and oral administration of Pyridostigmine (90 - 240 mg each day) and Prednisone (30 - 60 mg each day). The control group were treated with oral administration of Pyridostigmine (240-480 mg each day) and Prednisone (60-100 mg each day). Clinical therapeutic effects and serum Interleukin-4 (IL-4) levels before and after treatment were observed. RESULTS: The total effective rate was 93.3% in the observation group, which was better than 70.0% in the control group (P < 0.01); after treatment, the serum IL-4 levels in the two groups significantly decreased (P < 0.01), the decrease of IL-4 in the observation group being significantly better than the control group (P < 0.05). CONCLUSION: EA warming therapy combined with western medicine has a significant therapeutic effect on myasthenia gravis. One of the mechanisms possibly is to restrain specific immune reaction by regulating the level of IL-4.

Extrapolating from animal studies to the efficacy in humans of a pretreatment combination against organophosphate poisoning.

The extrapolation from animal data to therapeutic effects in humans, a basic pharmacological issue, is especially critical in studies aimed to estimate the protective efficacy of drugs against nerve agent poisoning. Such efficacy can only be predicted by extrapolation of data from animal studies to humans. In pretreatment therapy against nerve agents, careful dose determination is even more crucial than in antidotal therapy, since excessive doses may lead to adverse effects or performance decrements. The common method of comparing dose per body weight, still used in some studies, may lead to erroneous extrapolation. A different approach is based on the comparison of plasma concentrations at steady state required to obtain a given pharmacodynamic endpoint. In the present study, this approach was applied to predict the prophylactic efficacy of the anticholinergic drug caramiphen in combination with pyridostigmine in man based on animal data. In two species of large animals, dogs and monkeys, similar plasma concentrations of caramiphen (in the range of 60-100 ng/ml) conferred adequate protection against exposure to a lethal-dose of sarin (1.6-1.8 LD(50)). Pharmacokinetic studies at steady state were required to achieve the correlation between caramiphen plasma concentrations and therapeutic effects. Evaluation of total plasma clearance values was instrumental in establishing desirable plasma concentrations and minimizing the number of animals used in the study. Previous data in the literature for plasma levels of caramiphen that do not lead to overt side effects in humans (70-100 ng/ml) enabled extrapolation to expected human protection. The method can be applied to other drugs and other clinical situations, in which human studies are impossible due to ethical considerations. When similar dose response curves are obtained in at least two animal models, the extrapolation to expected therapeutic effects in humans might be considered more reliable.

Electroacupuncture warming therapy combined with western medicine for treatment of myasthenia gravis and effect on IL-4 level in the patients / 中国针灸

<p><b>OBJECTIVE</b>To observe the therapeutic effect of electroacupuncture (EA) warming therapy on myasthenia gravis (MG) and effect on IL-4 in the patient.</p><p><b>METHODS</b>Sixty patients with MG were randomly divided into two groups, 30 patients in each group. The observation group were treated with EA warming therapy with Tanzhong (CV 17), Shimen (CV 5), Guanyuan (CV 4), Zhongwan (CV 12), Yanglingquan (GB 34) selected as main points, and oral administration of Pyridostigmine (90 - 240 mg each day) and Prednisone (30 - 60 mg each day). The control group were treated with oral administration of Pyridostigmine (240-480 mg each day) and Prednisone (60-100 mg each day). Clinical therapeutic effects and serum Interleukin-4 (IL-4) levels before and after treatment were observed.</p><p><b>RESULTS</b>The total effective rate was 93.3% in the observation group, which was better than 70.0% in the control group (P < 0.01); after treatment, the serum IL-4 levels in the two groups significantly decreased (P < 0.01), the decrease of IL-4 in the observation group being significantly better than the control group (P < 0.05).</p><p><b>CONCLUSION</b>EA warming therapy combined with western medicine has a significant therapeutic effect on myasthenia gravis. One of the mechanisms possibly is to restrain specific immune reaction by regulating the level of IL-4.</p>