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Brain, Behavior, and Immunity Aug 2019Gulf War Illness (GWI) is characterized by a constellation of symptoms that includes cognitive dysfunction. While the causes for GWI remain unknown, prophylactic use of...
Gulf War Illness (GWI) is characterized by a constellation of symptoms that includes cognitive dysfunction. While the causes for GWI remain unknown, prophylactic use of the acetylcholinesterase inhibitor pyridostigmine bromide (PB) in combination with the stress of deployment has been proposed to be among the causes of the cognitive dysfunction in GWI. Mechanistically, clinical studies suggest that altered immune function may be an underlying factor in the neurochemical and neurobehavioral complications of GWI. Accordingly, the goal of this study was to determine how responses to an immune challenge (lipopolysaccharide; LPS) or stress impacts inflammation, acetylcholine (ACh) neurochemistry and behavior in an experimental model of GWI. Rats with a history of PB treatment exhibited potentiated increases in C-reactive protein levels in response to a submaximal LPS challenge compared to control rats, indicating that prior treatment with this cholinesterase inhibitor leads to exacerbated inflammatory responses to a subsequent immune challenge. ACh responses to LPS administration were decreased in the hippocampus, but not prefrontal cortex (PFC), in rats with a prior history of PB treatment or stress exposure. Additionally, ACh release in response to acute immobilization stress was attenuated in the PFC and hippocampus in these groups. These attenuated cholinergic responses were accompanied by impairments in contextual and cue-based fear learning. The results of this study suggest that stress and LPS challenges adversely affect central ACh neurochemistry in a rodent model of GWI and support the hypothesis that dysregulated immune responses are mechanistically linked to the neurological complications of GWI.
Topics: Acetylcholine; Animals; Behavior, Animal; C-Reactive Protein; Cholinesterase Inhibitors; Conditioning, Classical; Disease Models, Animal; Fear; Hippocampus; Inflammation; Lipopolysaccharides; Male; Persian Gulf Syndrome; Prefrontal Cortex; Pyridostigmine Bromide; Rats, Sprague-Dawley; Stress, Psychological
PubMed: 30953774
DOI: 10.1016/j.bbi.2019.04.015 -
Photodiagnosis and Photodynamic Therapy Mar 2023Although the mechanism is not clear, the inability of the orbicularis oculi muscle, especially the deeper segment (Horner muscle), is thought to be responsible in...
BACKGROUND
Although the mechanism is not clear, the inability of the orbicularis oculi muscle, especially the deeper segment (Horner muscle), is thought to be responsible in epiphora. This study evaluates the effect of the anticholinergic drug pyridostigmine (Mestinon) in patients with patent but dysfunctional lacrimal drainage system.
MATERIAL AND METHODS
Twenty patients with bilateral epiphora (mean age:60.78 ± 6.49 yrs) were included in this study. Patients with a patent lacrimal irrigation test based on persistent and symptomatic epiphora, wiping >10 times daily or continuous tearing and grade 4-5 epiphora according to Munk scale, showing neuropathic involvement in the orbicularis oculi muscle by the quantitative motor unit potential (MUP) analysis method were evaluated prospectively. Fluorescein dye disappearance test (a semi-quantitative assessment of delayed tear outflow) together with a Schirmer test reading were performed in order to detect dry eye. The patients were evaluated for tear meniscus measurements by anterior segment optical coherence topography (OCT) and non-invasive tear break-up time (NI-BUT) was measured by Oculus Keratograph 5 M. Those with a NI-BUT value above 10 s, without eyelid laxity, previous ocular surgery or ocular surface disease, or nasolacrimal duct obstruction, and who agreed to use the drug were included in the study. Each subject underwent OCT measurements of the lower tear meniscus of both eyes before and 15 mins after taking Mestinon (1 × 60 mg tablet). Upon measurement of the positive effect of the drug on tear meniscus height (TMH), the patients were asked to continue this regime daily for 1 month and then evaluated for relief in their epiphora complaints and any systemic drug side effects.
RESULTS
A total of 20 patients (40 eyes) with bilateral epiphora were included in the study. All eyes had grade 4 Munk-score epiphora, Schirmer's test was within the normal range in all eyes (mean, 14 ± 4 mm), and patent lacrimal irrigation test. The lower mean TMH reductions 15 min after Mestinon in the right and left eyes were 135.41 ± 85.47 and 55.44 ± 61.56 mm, respectively, a statistically significant decrease in both eyes (p = 0.001, p < 0.01). The mean tear meniscus area (TMA) in the right and left eyes was 131.83 ± 68.27 mm and 62.72 ± 50.57 mm, respectively; 15 mins after administration of Mestinon, the mean TMA in the right and left eyes was 77.27 ± 48.34 and 59.18 ± 44.74 mm, respectively (p = 0.001, p < 0.01). The mean decreases of 54.56 ± 39.34 mm in the right eye area and 3.53 ± 42.32 mm in the left eye area were statistically significant (p = 0.041, p < 0.05).
CONCLUSION
Symptomatic relief for epiphora cannot be achieved with known treatment options due to lacrimal pump dysfunction. We found that pyridostigmine (Mestinon) provided relief in patients' complaints of epiphora consistent with a significant reduction in TMH levels.
Topics: Humans; Middle Aged; Aged; Pyridostigmine Bromide; Lacrimal Duct Obstruction; Nasolacrimal Duct; Tomography, Optical Coherence; Photochemotherapy; Photosensitizing Agents
PubMed: 36592783
DOI: 10.1016/j.pdpdt.2022.103240 -
Scientific Reports May 2021The mechanisms regulating immune cells recruitment into the heart during healing after an acute myocardial infarction (AMI) have major clinical implications. We...
The mechanisms regulating immune cells recruitment into the heart during healing after an acute myocardial infarction (AMI) have major clinical implications. We investigated whether cholinergic stimulation with pyridostigmine, a cholinesterase inhibitor, modulates heart and spleen immune responses and cardiac remodeling after AMI in spontaneous hypertensive rats (SHRs). Male adult SHRs underwent sham surgery or ligation of the left coronary artery and were randomly allocated to remain untreated or to pyridostigmine treatment (40 mg/kg once a day by gavage). Blood pressure and heart rate variability were determined, and echocardiography was performed at day six after MI. The heart and spleen were processed for immunohistochemistry cellular analyses (CD3 and CD4 lymphocytes, and CD68 and CD206 macrophages), and TNF levels were determined at day seven after MI. Pyridostigmine treatment increased the parasympathetic tone and T CD4 lymphocytes in the myocardium, but lowered M1/M2 macrophage ratio towards an anti-inflammatory profile that was associated with decreased TNF levels in the heart and spleen. Treatment with this cholinergic agent improved heart remodeling manifested by lower ventricular diameters and better functional parameters. In summary, cholinergic stimulation by pyridostigmine enhances the parasympathetic tone and induces anti-inflammatory responses in the heart and spleen fostering cardiac recovery after AMI in SHRs.
Topics: Animals; Autonomic Nervous System; Blood Pressure; Cholinesterase Inhibitors; Heart; Heart Rate; Hemodynamics; Male; Myocardial Infarction; Pyridostigmine Bromide; Rats; Rats, Inbred SHR; Spleen
PubMed: 33953291
DOI: 10.1038/s41598-021-89104-8 -
Case Reports in Neurology 2021It remains uncertain to what extent lower urinary tract (LUT) symptom (LUTS) is a comorbidity of myasthenia gravis (MG). We prospectively administered a LUTS...
It remains uncertain to what extent lower urinary tract (LUT) symptom (LUTS) is a comorbidity of myasthenia gravis (MG). We prospectively administered a LUTS questionnaire devised for detecting neurogenic pelvic organ dysfunction (not validated) in an MG group and a healthy control group and compared the results. The MG group comprised 21 patients: 15 women and 6 men, with age range 22-73 (mean 47) years, illness duration range 0.2-8 (mean 3.5) years, median Myasthenia Gravis Foundation of America (MGFA) grade 2, all walking independently. Therapies included thymectomy in 17, predonisolone 5-20 mg/day in 10, and pyridostigmine bromide 60-180 mg/day in 9 patients. The control group, who were undergoing an annual health survey, comprised 235 consecutive subjects: 120 women and 115 men, with age range 30-69 (mean 48) years. The questionnaire had 9 questions. Each question was scored from 0 (none) to 3 (severe) with an additional quality of life (QOL) index scored from 0 (satisfied) to 3 (extremely dissatisfied). Statistical analysis was made using Student's test. Compared with the control subjects, the frequency of LUTSs in the MG patients was significantly higher for daytime frequency (43%; < 0.01), nocturia (24%; < 0.01), and urinary incontinence (43%; < 0.05). The LUTS-related QOL index for the MG patients was significantly higher for MG patients as a whole than that for all control patients (29%) ( < 0.05). In conclusion, our study results showed that MG patients had significantly more LUTSs (overactive bladder) than healthy control subjects and had worse LUTS-related QOL; therefore, amelioration of LUTS in MG is important.
PubMed: 34413752
DOI: 10.1159/000514825 -
BMJ Case Reports Apr 2021We report a case of a 55-year-old man presenting with diplopia, masticatory weakness and dysarthria several weeks post multitrauma. The clinical suspicion of myasthenia...
We report a case of a 55-year-old man presenting with diplopia, masticatory weakness and dysarthria several weeks post multitrauma. The clinical suspicion of myasthenia gravis (MG) was supported with positive acetylcholine receptor antibodies and abnormal repetitive stimulation study. He responded well to pyridostigmine, intravenous immunoglobulin and oral prednisolone. In this report, we describe the timing and progression of MG in our patient, and review the literature pertaining to the relationship between trauma and MG. The search for definitive evidence of causation may be impractical, but should not delay the recognition and management of a treatable condition.
Topics: Blepharoptosis; Diplopia; Humans; Male; Middle Aged; Myasthenia Gravis; Prednisolone; Pyridostigmine Bromide; Wounds and Injuries
PubMed: 33811091
DOI: 10.1136/bcr-2020-238415 -
Neurotoxicology May 2022Gulf War illness (GWI) is a chronic, multi-symptom disorder that has impacted approximately one third of Gulf War veterans. GWI and its symptoms have been linked to the...
Gulf War illness (GWI) is a chronic, multi-symptom disorder that has impacted approximately one third of Gulf War veterans. GWI and its symptoms have been linked to the exposure to neurological chemicals, including the anti-nerve gas drug pyridostigmine bromide (PB) and the insecticide permethrin (PER), among others. Mouse models utilizing these chemicals have reported symptomology analogous to human GWI. These changes include behavioral and cognitive impairment, neuroinflammation and hippocampal pathogenesis. Disease modifying interventions that target these pathological components are desperately needed. Vagus nerve stimulation (VNS) is FDA approved for drug-resistant epilepsy and depression. VNS has also been used off-label to target a myriad of symptoms, some of which are encompassed within the Kansas and CDC definitions of clinical GWI symptomology. A GWI animal model in which mice are exposed to a daily injection of PB and PER for 10 consecutive days has been shown to exhibit cognitive impairment and hippocampal pathology. The purpose of this study was to determine if 2-4 weeks of continuous vagus nerve stimulation initiated at 32 weeks after exposure to PB and PER would improve cognitive performance and hippocampal pathology. The results of the study revealed that exposure to PB and PER produces long-term cognitive deficits and reduced hippocampal neurogenesis. The results also showed that the VNS treatment was anxiolytic, improved some aspects of pattern separation deficits, and mitigated the reduced hippocampal neurogenesis. Thus, VNS improves outcomes in a mouse model of GWI and should be examined as a potential therapeutic strategy for mitigating some symptomology associated with GWI.
Topics: Animals; Disease Models, Animal; Gulf War; Mice; Neurogenesis; Permethrin; Persian Gulf Syndrome; Pyridostigmine Bromide; Vagus Nerve Stimulation
PubMed: 35421512
DOI: 10.1016/j.neuro.2022.04.001 -
International Journal of Pharmaceutics Nov 2021Changes of weight and axial expansion of tablets of the deliquescent drug pyridostigmine bromide with Kollidon SR were followed with relative humidity (RH) using dynamic...
Monitoring the weight and dimensional expansion of pyridostigmine bromide tablets under dynamic vapor sorption and impact of deliquescence on tablet strength and drug release.
Changes of weight and axial expansion of tablets of the deliquescent drug pyridostigmine bromide with Kollidon SR were followed with relative humidity (RH) using dynamic vapor sorption and displacement transducer. The effects of RH on placebo and drug containing (API) tablets prepared at low and high compression were related to tablet strength and molecular changes. Tablet weight and expansion increased with RH, especially above RH 40%. Tablet rigidity and strength decreased linearly with moisture for placebo tablets whereas for API tablets there was decrease up to 50% followed by large drop at 60%. Raman spectra of tablets did not show chemical interactions due to moisture, but decreased intensity of drug peak at 2370 cm indicating solid state changes. Decrease of polymer peak intensities at 805 and 1740 cm occurred only in API tablets implicating drug deliquescence in polymer moisture sorption. X-ray diffraction and thermal analysis of tablets indicated complete drug liquefaction after exposure at 60% RH, which impacted great loss of strength but did not affect the sustained release profile. In conclusion, monitoring of the physical properties of tablets during production of deliquescent drugs is necessary to avoid pitfalls during downstream processes such as coating, packaging and storage.
Topics: Drug Liberation; Humidity; Pyridostigmine Bromide; Tablets; X-Ray Diffraction
PubMed: 34600060
DOI: 10.1016/j.ijpharm.2021.121150 -
Neurotoxicology Dec 2018Gulf war illness (GWI) is a chronic multi-symptom disease that afflicts 25-33% of troops that were deployed in the 1990-1991 Gulf War. GWI symptoms include cognitive,...
Gulf war illness (GWI) is a chronic multi-symptom disease that afflicts 25-33% of troops that were deployed in the 1990-1991 Gulf War. GWI symptoms include cognitive, behavioral and emotional deficits, as well as migraines and pain. It is possible that exposure to Gulf War agents and prophylactics contributed to the reported symptomology. Pyridostigmine bromide (PB) and permethrin (PER) were given to protect from nerve gas attacks and insect vector born disease, respectively. Previous studies have demonstrated that 10 days of exposure to these chemicals can cause symptoms analogous to those observed in GWI, including impairment of long-term memory in mice. Other studies using this model have shown chronic neuroinflammation, and chronic neuroinflammation can lead to altered nociceptive sensitivity. At 10-weeks after the 10-day PB and PER exposure paradigm, we observed lowered nociceptive threshold on the Von Frey test that was no longer evident at 28 weeks and 38 weeks post-exposure. We further determined that vagus nerve stimulation, initiated at 38 weeks after exposure, restores the lowered nociceptive sensitivity. Therefore, stimulating the vagus nerve appears to influence nociception. Future studies are need to elucidate possible mechanisms of this effect.
Topics: Animals; Chemical Warfare Agents; Cholinesterase Inhibitors; Mice; Nociception; Pain Threshold; Permethrin; Persian Gulf Syndrome; Pyridostigmine Bromide; Vagus Nerve Stimulation
PubMed: 30273628
DOI: 10.1016/j.neuro.2018.09.007 -
FASEB Journal : Official Publication of... May 2019Gulf War illness (GWI) is a chronic multisymptom disorder that is prominent in Gulf War veterans. Major unexplained symptoms of GWI include functional gastrointestinal...
Gulf War illness (GWI) is a chronic multisymptom disorder that is prominent in Gulf War veterans. Major unexplained symptoms of GWI include functional gastrointestinal disorders and undiagnosed illnesses, including neurologic disorders. Exposure to the antinerve gas drug pyridostigmine bromide (PB) is linked to the development of GWI, but the exact mechanisms remain unclear. Here, we tested the hypothesis that PB alters gut function by disrupting the neural and immune systems of the intestine. We exposed male and female mice to physiologically comparable amounts of PB that match the dose, route, and time frame of exposure experienced by Gulf War veterans and assessed the acute and chronic impacts on gastrointestinal functions, the functional architecture of the enteric nervous system, and immune responses in the gut and brain. Exposure to PB drove acute alterations to colonic motility and structure in both male and female mice that transitioned to chronic changes in gut functions. PB drove acute alterations to enteric neural and glial activity, glial reactivity, and neuron survival with glial reactivity persisting into the chronic phase in male mice. Despite having no effect on colonic permeability, exposure to PB caused major shifts in the expression of proinflammatory cytokines and chemokines in the colon and brain that suggest immunosuppressive effects. Interestingly, immune disruption was still evident in the colon and brain in female animals at 1 mo following exposure to PB. Together, our results show that the paradigm of PB exposure experienced by veterans of the Persian Gulf War contributes to long-lasting pathophysiology by driving enteric neuroinflammation, promoting immunosuppression, and altering functional anatomy of the colon in a sex-dependent manner.-Hernandez, S., Fried, D. E., Grubišić, V., McClain, J. L., Gulbransen, B. D. Gastrointestinal neuroimmune disruption in a mouse model of Gulf War illness.
Topics: Animals; Brain; Cholinesterase Inhibitors; Colon; Cytokines; Enteric Nervous System; Female; Gastrointestinal Motility; Male; Mice; Mice, Inbred C57BL; Neuroglia; Persian Gulf Syndrome; Pyridostigmine Bromide
PubMed: 30789759
DOI: 10.1096/fj.201802572R -
Cortex; a Journal Devoted To the Study... Jan 2016Veterans of Operation Desert Storm/Desert Shield - the 1991 Gulf War (GW) - are a unique population who returned from theater with multiple health complaints and... (Review)
Review
Veterans of Operation Desert Storm/Desert Shield - the 1991 Gulf War (GW) - are a unique population who returned from theater with multiple health complaints and disorders. Studies in the U.S. and elsewhere have consistently concluded that approximately 25-32% of this population suffers from a disorder characterized by symptoms that vary somewhat among individuals and include fatigue, headaches, cognitive dysfunction, musculoskeletal pain, and respiratory, gastrointestinal and dermatologic complaints. Gulf War illness (GWI) is the term used to describe this disorder. In addition, brain cancer occurs at increased rates in subgroups of GW veterans, as do neuropsychological and brain imaging abnormalities. Chemical exposures have become the focus of etiologic GWI research because nervous system symptoms are prominent and many neurotoxicants were present in theater, including organophosphates (OPs), carbamates, and other pesticides; sarin/cyclosarin nerve agents, and pyridostigmine bromide (PB) medications used as prophylaxis against chemical warfare attacks. Psychiatric etiologies have been ruled out. This paper reviews the recent literature on the health of 1991 GW veterans, focusing particularly on the central nervous system and on effects of toxicant exposures. In addition, it emphasizes research published since 2008, following on an exhaustive review that was published in that year that summarizes the prior literature (RACGWI, 2008). We conclude that exposure to pesticides and/or to PB are causally associated with GWI and the neurological dysfunction in GW veterans. Exposure to sarin and cyclosarin and to oil well fire emissions are also associated with neurologically based health effects, though their contribution to development of the disorder known as GWI is less clear. Gene-environment interactions are likely to have contributed to development of GWI in deployed veterans. The health consequences of chemical exposures in the GW and other conflicts have been called "toxic wounds" by veterans. This type of injury requires further study and concentrated treatment research efforts that may also benefit other occupational groups with similar exposure-related illnesses.
Topics: Brain Neoplasms; Cognition Disorders; Fatigue; Gulf War; Humans; Neurotoxins; Occupational Exposure; Persian Gulf Syndrome; Veterans
PubMed: 26493934
DOI: 10.1016/j.cortex.2015.08.022