OBJECTIVES

To describe the clinical profile and outcomes of a series of adult patients diagnosed with ocular myasthenia gravis and to evaluate the potential factors affecting the risk of generalization.

This retrospective cohort study involved a medical chart review of adult patients seen from 2012 to 2019 at the neuro-ophthalmology clinic of a tertiary Philippine hospital with a clinical diagnosis of ocular myasthenia gravis supported by serologic, electrophysiologic, or pharmacologic test results. Outcomes of interest were complete stable remission, pharmacologic remission, minimal manifestations, and generalization. Kaplan-Meier method and log-rank test were used to analyze the probability of generalization.

The study sample consisted of 16 patients. The female to male ratio was 3:1. Mean age at symptom onset was 39 years. All patients received pharmacologic treatment, while two patients underwent thymectomy. No patient had remission as of last follow-up. Three patients had conversion of ocular myasthenia gravis to generalized myasthenia gravis. Mean time from symptom onset to generalization was 10.7 months. The generalization curves of patients who were symptomatic for less than two years and those who were symptomatic for at least two years prior to consult were significantly different (p = 0.049).

In this single-center study, there was female predominance among adult patients diagnosed with ocular myasthenia gravis. The incidence of generalization was 4 per 100 person-years while the 2-year probability of generalization was 30%. Further study is needed in order to determine the factors affecting the risk of generalization.

OBJECTIVE: To investigate the effects of Bushen Huoxue Granule on the ubiquitin-proteasome system (UPS) in an in vitro model of Parkinson's disease. METHODS: After treated with 1-methyl-4-phenylpyridinium (MPP⁺, 1 mmol/L) for 24 h, the cells were incubated with drug-free serum, Madopar-containing serum or Bushen Huoxue Granule-containing serum (BCS, 5%, 10%, and 20%) for another 24 h. The levels of α-synuclein (α-syn), tyrosine hydroxylase (TH) and UPS-related proteins were detected by Western blot. The expression levels of α-syn in PC12 cells were also analyzed by Western blot after treated with proteasome inhibitor MG132 and WT-α-syn plasmid transfection, respectively, as well as the alterations induced by subsequent BCS intervention. Immunocytochemistry was performed to determine the changes in α-syn phosphorylation at serine 129 (pSer129-α-syn) expression. The 20S proteasome levels were measured by enzyme-linked immunosorbnent assay. RESULTS: BCS (volume fraction ⩽20%) intervention could alleviate the MMP⁺-induced cell viability decrease (P<0.05). In the MPP⁺ treated cells, α-syn was up-regulated, while TH and proteins of UPS such as ubiquitin (Ub), Ub binding with Ub-activating enzyme (UBE1), Parkin and Ub C-terminal hydrolase-1 (UCHL-1) were down-regulated (P<0.05). BCS intervention could attenuate the above changes (P<0.05). The activity of BCS on blocking α-syn accumulation was weakened by MG132 (P<0.05). While α-syn level was significantly increased in cells transfected with plasmid, and reduced by BCS intervention (P<0.05). pSer129-α-syn was increased in MPP⁺-induced PC12 cells, whereas decreased by later BCS intervention (P<0.05). The 20S proteasome activity of MPP⁺-induced PC12 cells was decreased, but increased after BCS intervention (P<0.05). CONCLUSION BCS intervention protected UPS function, increased 20S proteasome activity, promoted pathological α-syn clearance, restored cell viability, and reversed the damage caused by MPP⁺ in the in vitro model of Parkinson's disease.
PC12 Cells ; alpha-Synuclein/metabolism* ; Rats ; Animals ; 1-Methyl-4-phenylpyridinium/toxicity* ; Proteasome Endopeptidase Complex/metabolism* ; Drugs, Chinese Herbal/pharmacology* ; Ubiquitin/metabolism* ; Cell Survival/drug effects* ; Phosphorylation/drug effects* ; Tyrosine 3-Monooxygenase/metabolism*

OBJECTIVES: To investigate the role of ferroptosis in diquat-induced acute kidney injury (AKI) and its molecular mechanisms. METHODS: Transgenic zebrafish models with Tg (Eco.Tshb:EGFP) labeling of the renal tubules and Tg (lyz:dsRed2) labeling of the neutrophils were both divided into control group, gentamicin (positive control) group, diquat poisoning group, ferroptosis inhibitor group. The indicators of kidney injury, inflammatory response, and ferroptosis were examined in the zebrafish, and the changes in expressions of voltage-dependent anion-selective channel protein 1 (VDAC1) and mitochondrial ferritin (FTMT) were detected using Western blotting. RESULTS: AKI induced by diquat exhibited a significant dose-effect relationship, and the severity of injury was proportional to the exposure concentration. Diquat also caused marked oxidative stress and inflammatory responses in the zebrafish models. Rhodamine metabolism assay and HE staining revealed significantly declined glomerular filtration function of the zebrafish as diquat exposure concentration increased. Immunofluorescence staining highlighted significant changes in the expressions of ferroptosis markers GPX4 and FTH1 in zebrafish renal tissues following diquat exposure. In diquat-exposed zebrafish, treatment with ferrostatin-1, a ferroptosis inhibitor, obviously upregulated GPX4 and downregulated FTH1 expressions and improved the metabolic rate of glucan labeled with rhodamine B. Diquat exposure significantly upregulated the expression of VDAC1 and FTMT in zebrafish, and the application of ferrostatin-1 and VBIT-12 (a VDAC1 inhibitor) both caused pronounced downregulation of FTMT expression. CONCLUSIONS Ferroptosis is a critical mechanism underlying diquat-induced AKI, in which VDAC1 and FTMT play important regulatory roles, suggesting their potential as therapeutic target for AKI caused by diquat.
Animals ; Zebrafish ; Ferroptosis/drug effects* ; Acute Kidney Injury/chemically induced* ; Diquat/toxicity* ; Animals, Genetically Modified ; Voltage-Dependent Anion Channel 1/metabolism* ; Ferritins/metabolism* ; Oxidative Stress

OBJECTIVE: To investigate whether auraptene (AUR) exerts a protective effect on acute diquat (DQ)-induced liver injury in mice and explore its underlying mechanisms. METHODS: Forty SPF-grade healthy male C57BL/6 mice were randomly divided into normal control group (Control group), DQ poisoning model group (DQ group), AUR treatment group (DQ+AUR group), and AUR control group (AUR group), with 10 mice in each group. The DQ poisoning model was established via a single intraperitoneal injection of 40 mg/kg DQ aqueous solution (0.5 mL); Control group and AUR group received an equal volume of pure water intraperitoneally. Four hours post-modeling, DQ+AUR group and AUR group were administered 0.5 mg/kg AUR aqueous solution (0.2 mL) by gavage once daily for 7 consecutive days, while Control group and DQ group received pure water. Blood and liver tissues were collected after anesthesia on day 7. Liver ultrastructure was observed by transmission electron microscopy. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured via enzyme-linked immunosorbent assay (ELISA). Hepatic glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA) levels were detected using WST-1, thiobarbituric acid (TBA), and enzymatic reaction methods, respectively. Protein expression of nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), Kelch-like ECH-associated protein 1 (Keap1), and activated caspase-9 in liver tissues was analyzed by Western blotting. RESULTS: Transmission electron microscopy revealed that mitochondria in the Control group exhibited mild swelling, uneven distribution of matrix, and a small number of cristae fractures. In the AUR group, mitochondria showed mild swelling, with no obvious disruption of cristae structure. In the DQ group, mitochondria demonstrated marked swelling and increased volume, matrix dissolution, loss and fragmentation of cristae, and extensive vacuolization. In contrast, the DQ+AUR group showed significantly reduced mitochondrial swelling, volume increase, matrix dissolution, cristae loss and fragmentation, and vacuolization compared to the DQ group. Compared with the DQ group, the DQ+AUR group exhibited significantly lower serum AST levels (U/L: 173.45±23.60 vs. 255.33±41.51), ALT levels (U/L: 51.77±21.63 vs. 100.70±32.35), and hepatic MDA levels (μmol/g: 12.40±2.76 vs. 19.74±4.10), along with higher hepatic GSH levels (mmol/g: 37.65±14.95 vs. 20.58±8.52) and SOD levels (kU/g: 124.10±33.77 vs. 82.81±22.00), the differences were statistically significant (all P < 0.05). Western blotting showed upregulated Nrf2 expression (Nrf2/β-actin: 0.87±0.37 vs. 0.53±0.22) and HO-1 expression (HO-1/β-actin: 1.06±0.22 vs. 0.49±0.08), and downregulated Keap1 expression (Keap1/β-actin: 0.82±0.12 vs. 1.52±0.76) and activated caspase-9 expression (activated caspase-9/β-actin: 1.16±0.28 vs. 1.71±0.30) in the DQ+AUR group compared to the DQ group (all P < 0.05). CONCLUSION AUR attenuates DQ-induced acute liver injury in mice by activating the Keap1/Nrf2 signaling pathway.
Animals ; Male ; Mice ; Mice, Inbred C57BL ; Liver/pathology* ; Chemical and Drug Induced Liver Injury/drug therapy* ; Diquat/poisoning* ; NF-E2-Related Factor 2/metabolism* ; Oxidative Stress ; Apoptosis ; Coumarins

OBJECTIVES

To describe the clinical profile and outcomes of a series of adult patients diagnosed with ocular myasthenia gravis and to evaluate the potential factors affecting the risk of generalization.

This retrospective cohort study involved a medical chart review of adult patients seen from 2012 to 2019 at the neuro-ophthalmology clinic of a tertiary Philippine hospital with a clinical diagnosis of ocular myasthenia gravis supported by serologic, electrophysiologic, or pharmacologic test results. Outcomes of interest were complete stable remission, pharmacologic remission, minimal manifestations, and generalization. Kaplan-Meier method and log-rank test were used to analyze the probability of generalization.

The study sample consisted of 16 patients. The female to male ratio was 3:1. Mean age at symptom onset was 39 years. All patients received pharmacologic treatment, while two patients underwent thymectomy. No patient had remission as of last follow-up. Three patients had conversion of ocular myasthenia gravis to generalized myasthenia gravis. Mean time from symptom onset to generalization was 10.7 months. The generalization curves of patients who were symptomatic for less than two years and those who were symptomatic for at least two years prior to consult were significantly different (p = 0.049).

In this single-center study, there was female predominance among adult patients diagnosed with ocular myasthenia gravis. The incidence of generalization was 4 per 100 person-years while the 2-year probability of generalization was 30%. Further study is needed in order to determine the factors affecting the risk of generalization.

OBJECTIVE: To investigate the protective effect and mechanism of tumor necrosis factor receptor-associated factor 6 (TRAF6) inhibitor C25-140 on acute kidney injury (AKI) induced by acute diquat (DQ) poisoning in mice. METHODS: A total of 80 SPF grade healthy male C57BL/6 mice were randomly divided into the normal control group, DQ model group, C25-140 intervention group, and C25-140 control group, with 20 mice in each group. The DQ poisoning mouse model was established by using one-time intraperitoneal injection of 1 mL of 40 mg/kg DQ solution. The normal control group and C25-140 control group were injected with an equal amount of pure water into the peritoneal cavity. After 4 hours of model establishment, the C25-140 intervention group and C25-140 control group were given intraperitoneal injection of C25-140 5 mg/kg. The normal control group and DQ model group were given equal amounts of pure water, once a day for 7 consecutive days. After 7 days, the mice were anesthetized, eye blood was collected, and renal tissue was collected after sacrifice. The pathological changes of renal tissue were observed under a light microscope and renal tissue structure and mitochondrial changes were observed under transmission electron microscopy. The levels of serum creatinine (SCr) and blood urea nitrogen (BUN) were measured. Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of serum interleukins (IL-6, IL-1β) and tumor necrosis factor-α (TNF-α). Western blotting was used to detect the protein expression levels of TRAF6, myeloid differentiation factor 88 (MyD88), and nuclear factor-κB (NF-κB) in renal tissue. Chemical method was used to determine the content of serum malondialdehyde (MDA) and superoxide dismutase (SOD). RESULTS: During the observation period, there were no abnormal behaviors in the normal control group mice. The DQ model group mice gradually showed symptoms such as mental fatigue, fluffy fur, reduced activity, and low food intake after being exposed to the toxin, and severe cases resulted in death. The above symptoms were alleviated in the C25-140 intervention group compared to the DQ model group. Under light microscopy, HE staining showed infiltration of inflammatory cells, glomerulosclerosis, proximal tubular dilation, and vacuolization in the DQ model group, while the inflammatory response was reduced in the C25-140 intervention group compared to the DQ model group. Under transmission electron microscopy, the DQ model group showed relatively high levels of mitochondrial damage, severe swelling, increased volume, matrix dissolution, ridge fracture and loss. The degree of mitochondrial damage in the C25-140 intervention group was reduced compared to the DQ model group. Compared with the normal control group, the levels of serum SCr, BUN, IL-6, IL-1β, TNF-α, and MDA in the DQ model group were significantly increased, while the serum SOD level was significantly decreased. Compared with the DQ model group, the levels of serum SCr, BUN, IL-6, IL-1β, TNF-α, and MDA in the C25-140 intervention group were significantly reduced [SCr (μmol/L): 59.07±13.11 vs. 83.61±20.13, BUN (mmol/L): 25.83±9.95 vs. 40.78±11.53, IL-6 (ng/L): 40.76±7.03 vs. 83.33±21.83, IL-1β (ng/L): 53.87±7.82 vs. 91.74±12.53, TNF-α (ng/L): 102.52±32.13 vs. 150.92±31.75, MDA (μmol/L): 3.57±1.06 vs. 5.75±1.83], and the serum SOD level was significantly increased (kU/g: 162.52±36.13 vs. 122.72±22.13), and the differences were statistically significant (all P < 0.01). Western blotting results showed that the protein expression levels of TRAF6, NF-κB, and MyD88 in the renal tissue of DQ model group mice were significantly higher than those in the normal control group. The expression levels of the above-mentioned proteins in the C25-140 intervention group of mice were significantly lower than those in the DQ model group (TRAF6/β-actin: 1.05±0.36 vs. 1.74±0.80, NF-κB/β-actin: 0.57±0.07 vs. 1.03±0.75, MyD88/β-actin: 0.58±0.07 vs. 1.03±0.33, all P < 0.05). CONCLUSIONS TRAF6 inhibitor C25-140 can alleviate AKI induced by DQ poisoning in mice by regulating the Toll-like receptor 4 (TLR4)/TRAF6/NF-κB signaling pathway and downregulating the levels of inflammatory cytokines IL-1β, IL-6, and TNF-α.
Animals ; Male ; Acute Kidney Injury/prevention & control* ; Mice ; Mice, Inbred C57BL ; Diquat ; TNF Receptor-Associated Factor 6/metabolism* ; Interleukin-6/blood* ; Kidney/pathology* ; NF-kappa B/metabolism* ; Peptide Fragments

OBJECTIVE: To observe whether metformin (MET) inhibits transforming growth factor-β₁ (TGF-β₁)/Smad3 signaling pathway by activating adenosine activated protein kinase (AMPK), so as to alleviate the pulmonary fibrosis caused by paraquat (PQ) poisoning in mice. METHODS: Male C57BL/6J mice were randomly divided into the Control group, PQ poisoning model group (PQ group), MET intervention group (PQ+MET group), AMPK agonist group (PQ+AICAR group), and AMPK inhibitor group (PQ+MET+CC group), according to a random number table method. A mouse model of PQ poisoning was established by one-time peritoneal injection of 1 mL PQ solution (20 mg/kg). The Control group was injected with the same volume of normal saline. After 2 hours of modeling, the PQ+MET group was given 2 mL of 200 mg/kg MET solution by gavage, the PQ+AICAR group was given 2 mL of 200 mg/kg AICAR solution by intraperitoneal injection, the PQ+MET+CC group was given 2 mL of 200 mg/kg MET solution by gavage and then 1 mL complex C (CC) solution (20 mg/kg) was intraperitoneally injected, the Control group and PQ group were given 2 mL of normal saline by gavage. The intervention was given once a day for 21 consecutive days. The 21-day survival rate of ten mice in each group was calculated, and the lung tissues of remaining mice were collected at 21 days after modeling. The pathological changes of lung tissues were observed under light microscope after hematoxylin-eosin (HE) staining and Masson staining, and the degree of pulmonary fibrosis was evaluated by Ashcroft score. The content of hydroxyproline in lung tissue and oxidative stress indicators such as malondialdehyde (MDA) and superoxide dismutase (SOD) were detected. The protein expressions of E-cadherin, α-smooth muscle actin (α-SMA), phosphorylated AMPK (p-AMPK), TGF-β₁ and phosphorylated Smad3 (p-Smad3) in lung tissue were detected by Western blotting. RESULTS: Compared with the Control group, the 21 days survival rate was significantly reduced, lung fibrosis and Ashcroft score were significantly increased in PQ group. In addition, the content of hydroxyproline, MDA and the protein expressions of α-SMA, TGF-β₁ and p-Smad3 in lung tissue were significantly increased, while the activity of SOD and the protein expressions of E-cadherin and p-AMPK were significantly decreased in PQ group. Compared with the PQ group, the 21 days survival rates of mice were significantly improved in the PQ+MET group and PQ+AICAR group (70%, 60% vs. 20%, both P < 0.05). The degree of pulmonary fibrosis and the Ashcroft score were significantly reduced (1.50±0.55, 2.00±0.63 vs. 6.67±0.52, both P < 0.05). The content of hydroxyproline and MDA in lung tissue, as well as α-SMA, TGF-β₁ and p-Smad3 protein expressions were significantly reduced [hydroxyproline (mg/L): 2.03±0.11, 3.00±0.85 vs. 4.92±0.65, MDA (kU/g): 2.06±1.48, 2.10±1.80 vs. 4.06±1.33, α-SMA/GAPDH: 0.23±0.06, 0.16±0.06 vs. 1.00±0.09, TGF-β₁/GAPDH: 0.28±0.03, 0.53±0.05 vs. 0.92±0.06 p-Smad3/GAPDH: 0.52±0.04, 0.69±0.06 vs. 1.11±0.10, all P < 0.05], SOD activity and the protein expressions of E-cadherin and p-AMPK were significantly increased [SOD (μmol/g): 39.76±1.35, 33.03±1.28 vs. 20.08±1.79, E-cadherin/GAPDH: 0.91±0.08, 0.72±0.08 vs. 0.26±0.04, p-AMPK/GAPDH: 0.62±0.04, 0.60±0.01 vs. 0.20±0.04, all P < 0.05]. However, these protective effects of MET were inhibited by the addition of AMPK inhibitor CC solution. CONCLUSIONS MET can effectively alleviate the degree of pulmonary fibrosis in mice poisoned with PQ, and its mechanism may be related to the activation of AMPK and inhibition of TGF-β₁/Smad3 signaling pathway, which can be inhibited by AMPK inhibitor CC.
Mice ; Male ; Animals ; Pulmonary Fibrosis/drug therapy* ; Paraquat ; AMP-Activated Protein Kinases/pharmacology* ; Metformin/pharmacology* ; Hydroxyproline/pharmacology* ; Saline Solution ; Mice, Inbred C57BL ; Lung/metabolism* ; Transforming Growth Factor beta1/pharmacology* ; Cadherins ; Superoxide Dismutase

OBJECTIVE: To observe the toxicokinetic parameters, absorption characteristics and pathomorphological damage in different parts of the gastrointestinal tract of rats poisoned with different doses of diquat (DQ). METHODS: Ninety-six healthy male Wistar rats were randomly divided into a control group (six rats) and low (115.5 mg/kg), medium (231.0 mg/kg) and high (346.5 mg/kg) dose DQ poisoning groups (thirty rats in each dose group), and then the poisoning groups were randomly divided into 5 subgroups according to the time after exposure (15 minutes and 1, 3, 12, 36 hours; six rats in each subgroup). All rats in the exposure groups were given a single dose of DQ by gavage. Rats in the control group was given the same amount of saline by gavage. The general condition of the rats was recorded. Blood was collected from the inner canthus of the eye at 3 time points in each subgroup, and rats were sacrificed after the third blood collection to obtain gastrointestinal specimens. DQ concentrations in plasma and tissues were determined by ultra-high performance liquid chromatography and mass spectrometry (UPHLC-MS), and the toxic concentration-time curves were plotted to calculate the toxicokinetic parameters; the morphological structure of the intestine was observed under light microscopy, and the villi height and crypt depth were determined and the ratio (V/C) was calculated. RESULTS: DQ was detected in the plasma of the rats in the low, medium and high dose groups 5 minutes after exposure. The time to maximum plasma concentration (Tmax) was (0.85±0.22), (0.75±0.25) and (0.25±0.00) hours, respectively. The trend of plasma DQ concentration over time was similar in the three dose groups, but the plasma DQ concentration increased again at 36 hours in the high dose group. In terms of DQ concentration in gastrointestinal tissues, the highest concentrations of DQ were found in the stomach and small intestine from 15 minutes to 1 hour and in the colon at 3 hours. By 36 hours after poisoning, the concentrations of DQ in all parts of the stomach and intestine in the low and medium dose groups had decreased to lower levels. Gastrointestinal tissue (except jejunum) DQ concentrations in the high dose group tended to increase from 12 hours. Higher doses of DQ were still detectable [gastric, duodenal, ileal and colonic DQ concentrations of 6 400.0 (1 232.5), 4 889.0 (6 070.5), 10 300.0 (3 565.0) and 1 835.0 (202.5) mg/kg respectively]. Light microscopic observation of morphological and histopathological changes in the intestine shows that acute damage to the stomach, duodenum and jejunum of rats was observed 15 minutes after each dose of DQ, pathological lesions were observed in the ileum and colon 1 hour after exposure, the most severe gastrointestinal injury occurred at 12 hours, significant reduction in villi height, significant increase in crypt depth and lowest V/C ratio in all segments of the small intestine, damage begins to diminish by 36-hour post-intoxication. At the same time, morphological and histopathological damage to the intestine of rats at all time points increased significantly with increasing doses of the toxin. CONCLUSIONS The absorption of DQ in the digestive tract is rapid, and all segments of the gastrointestinal tract may absorb DQ. The toxicokinetics of DQ-tainted rats at different times and doses have different characteristics. In terms of timing, gastrointestinal damage was seen at 15 minutes after DQ, and began to diminish at 36 hours. In terms of dose, Tmax was advanced with the increase of dose and the peak time was shorter. The damage to the digestive system of DQ is closely related to the dose and retention time of the poison exposure.
Animals ; Male ; Rats ; Diquat/toxicity* ; Gastrointestinal Diseases ; Intestines ; Poisons ; Rats, Wistar ; Toxicokinetics

Diquat is a kind of conductive contact-killing herbicides. The damage of central nervous system is relatively common, but the peripheral neuropathy caused by diquat has not been reported yet. In September 2021, we treated a patient with diquat poisoning. During the hospitalization, the patient was diagnosed with peripheral neuropathy. Therapy for peripheral nerve injury was given on the basis of conventional treatment of poisoning. The patient was discharged after his condition was stable. The follow-up showed that the peripheral neuropathy of patient was better than before. According to the condition of this patient, it is suggested that we should not only protect the function of gastrointestinal tract, liver, kidney, and central nervous system early, but should also pay attention to the damage of peripheral nervous system in clinical work. We should intervene earlier to improve the prognosis of patients.
Humans ; Diquat ; Herbicides ; Kidney ; Liver ; Peripheral Nerve Injuries ; Poisoning

Objective: To investigate the effects of duration, temperature and shake on paraquat (PQ) concentration in the blood of PQ-exposed rats during the specinen preservation and transportation. Methods: In March 2021, 60 SD male rats of Specific Pathogen Free class were randomly divided into low-dose group (10 mg/kg PQ) and high-dose group (80 mg/kg PQ). Each group was divided into 5 subgroups (normal temperature group, cold storage group, 37 ℃ storage group, shaking on normal temperature group and shaking on 37 ℃ group), six rats in each subgroup. The rats were given intraperitoneal injection of PQ, 1 h after exposure, the blood samples were obtained by cardiac extraction. After different interventions, the concentrations of PQ were detected and compared before and after the intervention in each subgroup. Results: In the shaking on 37 ℃ group, the results of PQ concentrations in PQ-exposed rats were significantly lower than those before the intervention (P<0.05). In the other subgroups, the results were not significantly different compared with before intervention (P>0.05) . Conclusion: The concentration of PQ in the blood of rats exposed to PQ was decreased by shaking for 4 hours at 37 ℃.
Rats ; Male ; Animals ; Rats, Sprague-Dawley ; Paraquat/pharmacology* ; Lung