Clinicopathologic characterization of cervical metastasis from an unknown primary tumor: a multicenter study in Korea

Background@#Research regarding cervical metastasis from an unknown primary tumor (CUP) according to human papillomavirus (HPV) and Epstein-Barr virus (EBV) status in Korea has been sporadic and small-scale. This study aims to analyze and understand the characteristics of CUP in Korea according to viral and p16 and p53 status through a multicenter study. @*Methods@#Ninety-five cases of CUP retrieved from six hospitals in Korea between January 2006 and December 2016 were subjected to high-risk HPV detection (DNA in situ hybridization [ISH] or real-time polymerase chain reaction), EBV detection (ISH), and immunohistochemistry for p16 and p53. @*Results@#CUP was HPV-related in 37 cases (38.9%), EBV-related in five cases (5.3%), and unrelated to HPV or EBV in 46 cases (48.4%). HPV-related CUP cases had the best overall survival (OS) (p = .004). According to the multivariate analysis, virus-unrelated disease (p = .023) and longer smoking duration (p < .005) were prognostic factors for poor OS. Cystic change (p = .016) and basaloid pattern (p < .001) were more frequent in HPV-related cases, and lymphoepithelial lesion was frequent in EBV-related cases (p = .010). There was no significant association between viral status and p53 positivity (p = .341), smoking status (p = .728), or smoking duration (p = .187). Korean data differ from Western data in the absence of an association among HPV, p53 positivity, and smoking history. @*Conclusions@#Virus-unrelated CUP in Korea had the highest frequency among all CUP cases. HPV-related CUP is similar to HPV-mediated oropharyngeal cancer and EBVrelated CUP is similar to nasopharyngeal cancer in terms of characteristics, respectively.

The Effect of Type of Communication by Physical Therapists on Patient Satisfaction and Revisit Intention

Purpose@#This study sought to identify the effect of various types of communication by physical therapists on patient satisfaction and revisit intention. @*Methods@#A total of 212 patients who received physical therapy in Seoul and the Gyeonggi province were surveyed on patient satisfaction and revisit intentions depending on the types of communication by physical therapists. Frequency and correlation analyses were conducted to process the data using the SPSS 22.0 program, and the AMOS 18.0 statistical package was used for confirmatory factor analysis. A structural equation modeling analysis was also performed to verify the model and the hypothesis that was set up in the present paper. @*Results@#The survey showed that patient satisfaction correlates positively and significantly with patient-centric communication, physical factors, and spatial behavior. A significant negative correlation was also found between patient satisfaction and therapist-centered communication. Patient satisfaction positively correlated with revisit intentions. @*Conclusion@#These results showed that there was a positive correlation between the communication of the physical therapist and the satisfaction recognized by a patient. This implies that the patient satisfaction with a physical therapist increases as the communication skills of a physical therapist improve. These findings suggest that a physical therapist must adopt patient-centric communication styles, physical factors, and spatial behavior. This study was important as it generated basic data for the formation of a therapeutic relationship through efficient and promotional communication skills. It recognizes the importance of communication between a physical therapist and a patient as the indispensable factor for interaction.

Suppression of ARID1A associated with decreased CD8 T cells improves cell survival of ovarian clear cell carcinoma / 부인종양

Objective@#AT-rich interactive domain 1A (ARID1A) plays an important role as a tumor suppressor gene in ovarian clear cell carcinoma (OCCC), but the clinical application of ARID1A remains unclear. The aim of this study was to analyze clinicopathological parameters, molecular interactions and immune-infiltration in patients with low ARID1A expression and to provide candidate target drugs. @*Methods@#We investigated the clinicopathologic parameters, specific gene sets/genes, and immunological relevance according to ARID1A expression in 998 OCCC patients from 12 eligible studies (using meta-analyses); 30 OCCC patients from the Hanyang University Guri Hospital (HYGH) cohort; and 52 OCCC patients from gene set enrichment (GSE) 65986 (25 patients), 63885 (9 patients), and 54809 (6 patients and 12 healthy people) of the Gene Expression Omnibus (GEO). We analyzed network-based pathways based on gene set enrichment analysis (GSEA) and performed in vitro drug screening. @*Results@#Low ARID1A expression was associated with poor survival in OCCC from the metaanalysis, HYGH cohort and GEO data. In GSEA, low ARID1A expression was related to the tumor invasion process as well as a low immune-infiltration. In silico cytometry showed that CD8 T cells were decreased with low ARID1A expression. In pathway analysis, ARID1A was associated with angiogenic endothelial cell signaling. In vitro drug screening revealed that cabozantinib and bicalutamide effectively inhibited specific hub genes, such as vascular endothelial growth factor-A and androgen receptor, in OCCC cells with low ARID1A expression. @*Conclusions@#Therapeutic strategies making use of low ARID1A could contribute to better clinical management/research for patients with OCCC.

Deletion of adipose triglyceride lipase abolishes blood flow increase after β3-adrenergic stimulation in visceral adipose tissue of mice

Dynamic changes in adipose tissue blood flow (ATBF) with nutritional status play a role in the regulation of metabolic and endocrine functions. Activation of the sympathetic nervous system via β-adrenergic receptors (β-AR) contributes to the control of postprandial enhancement of ATBF. Herein, we sought to identify the role of each β-AR subtype in the regulation of ATBF in mice. We monitored the changes in visceral epididymal ATBF (VAT BF), induced by local infusion of dobutamine, salbutamol, and CL316,243 (a selective β1-, β2-, and β3-AR agonist, respectively) into VAT of lean CD-1 mice and global adipose triglyceride lipase (ATGL) knockout (KO) mice, using laser Doppler flowmetry. Administration of CL316,243, known to promote lipolysis in adipocytes, significantly increased VAT BF of CD-1 mice to a greater extent compared to that of the vehicle, whereas administration of dobutamine or salbutamol did not produce significant differences in VAT BF. The increase in VAT BF induced by β3-AR stimulation disappeared in ATGL KO mice as opposed to their wild-type (WT) littermates, implying a role of ATGL-mediated lipolysis in the regulation of VAT BF. Different vascular reactivities occurred despite no significant differences in vessel density and adiposity between the groups. Additionally, the expression levels of the angiogenesis-related genes were significantly higher in VAT of ATGL KO mice than in that of WT, implicating an association of ATBF responsiveness with angiogenic activity in VAT. Our findings suggest a potential role of β3-AR signaling in the regulation of VAT BF via ATGL-mediated lipolysis in mice.

Proto-oncogene Pokemon in thyroid cancer: a potential promoter of tumorigenesis in papillary thyroid carcinoma

Background@#Pokemon is an oncogenic transcription regulator that plays a critical role in cellular differentiation. Although it has been found to be overexpressed in several types of cancer involving different organs, its role in thyroid gland has yet to be reported. The objective of this study was to evaluate the expression of Pokemon in papillary thyroid carcinoma (PTC) based on clinicopathological parameters. @*Methods@#Tissue microarray samples derived from patients with PTC or benign thyroid disease were used to evaluate Pokemon expression based on immunohistochemical analysis. Correlations of its expression with various clinicopathological parameters were then analyzed. @*Results@#Pokemon expression was observed in 22.0% of thyroid follicular cells from the normal group, 44.0% from the group with benign thyroid diseases, and 92.1% from the group with PTC (p < .001). The intensity of Pokemon expression was markedly higher in the PTC group. Pokemon expression level and PTC tumor size showed an inverse correlation. T1a tumors showed strong expression levels of Pokemon. However, larger tumors showed weak expression (p = .006). @*Conclusions@#Pokemon expression is associated with tumorigenesis of PTC, with expression showing an inverse correlation with PTC tumor size. This might be related to the negative regulation of aerobic glycolysis by Pokemon.

Deletion of adipose triglyceride lipase abolishes blood flow increase after β3-adrenergic stimulation in visceral adipose tissue of mice

Dynamic changes in adipose tissue blood flow (ATBF) with nutritional status play a role in the regulation of metabolic and endocrine functions. Activation of the sympathetic nervous system via β-adrenergic receptors (β-AR) contributes to the control of postprandial enhancement of ATBF. Herein, we sought to identify the role of each β-AR subtype in the regulation of ATBF in mice. We monitored the changes in visceral epididymal ATBF (VAT BF), induced by local infusion of dobutamine, salbutamol, and CL316,243 (a selective β1-, β2-, and β3-AR agonist, respectively) into VAT of lean CD-1 mice and global adipose triglyceride lipase (ATGL) knockout (KO) mice, using laser Doppler flowmetry. Administration of CL316,243, known to promote lipolysis in adipocytes, significantly increased VAT BF of CD-1 mice to a greater extent compared to that of the vehicle, whereas administration of dobutamine or salbutamol did not produce significant differences in VAT BF. The increase in VAT BF induced by β3-AR stimulation disappeared in ATGL KO mice as opposed to their wild-type (WT) littermates, implying a role of ATGL-mediated lipolysis in the regulation of VAT BF. Different vascular reactivities occurred despite no significant differences in vessel density and adiposity between the groups. Additionally, the expression levels of the angiogenesis-related genes were significantly higher in VAT of ATGL KO mice than in that of WT, implicating an association of ATBF responsiveness with angiogenic activity in VAT. Our findings suggest a potential role of β3-AR signaling in the regulation of VAT BF via ATGL-mediated lipolysis in mice.

Proto-oncogene Pokemon in thyroid cancer: a potential promoter of tumorigenesis in papillary thyroid carcinoma

Background@#Pokemon is an oncogenic transcription regulator that plays a critical role in cellular differentiation. Although it has been found to be overexpressed in several types of cancer involving different organs, its role in thyroid gland has yet to be reported. The objective of this study was to evaluate the expression of Pokemon in papillary thyroid carcinoma (PTC) based on clinicopathological parameters. @*Methods@#Tissue microarray samples derived from patients with PTC or benign thyroid disease were used to evaluate Pokemon expression based on immunohistochemical analysis. Correlations of its expression with various clinicopathological parameters were then analyzed. @*Results@#Pokemon expression was observed in 22.0% of thyroid follicular cells from the normal group, 44.0% from the group with benign thyroid diseases, and 92.1% from the group with PTC (p < .001). The intensity of Pokemon expression was markedly higher in the PTC group. Pokemon expression level and PTC tumor size showed an inverse correlation. T1a tumors showed strong expression levels of Pokemon. However, larger tumors showed weak expression (p = .006). @*Conclusions@#Pokemon expression is associated with tumorigenesis of PTC, with expression showing an inverse correlation with PTC tumor size. This might be related to the negative regulation of aerobic glycolysis by Pokemon.

Obesidad, tejido adiposo y cirugía bariátrica / Obesity, adipose tissue, and bariatric surgery

Resumen En las últimas décadas, la prevalencia de la obesidad ha aumentado a escala mundial y ha provocado complicaciones metabólicas tales como diabetes de tipo 2, esteatosis, problemas cardiovasculares, entre otras. Su desarrollo puede estar influenciado por factores genéticos y ambientales, incluyendo la microbiota intestinal. En México, el 33.3% de la población adulta padece de este problema. La obesidad involucra un incremento excesivo del tejido adiposo que produce su disfunción. Se ha demostrado que la remodelación del tejido adiposo, dada por angiogénesis, hipoxia e inflamación, otorga susceptibilidad a desarrollar obesidad y conlleva a modificaciones metabólicas. La cirugía bariátrica ha sido el procedimiento más utilizado y más exitoso para tratar la obesidad mórbida en cuanto a la pérdida de peso corporal a largo plazo y a la remisión de comorbilidades como la diabetes tipo 2. En este artículo se revisan los aspectos moleculares por medio de los cuales la cirugía bariátrica provoca cambios metabólicos que se reflejan en la pérdida de peso y las mejoras metabólicas. Por lo tanto, se resumen aspectos genéticos, de microbioma y moleculares (remodelación del tejido adiposo) que influyen en el desarrollo de la obesidad. También se explican los aspectos moleculares a través de los cuales se puede modular la pérdida de peso y la mejoría de comorbilidades metabólicas.

Abstract Obesity prevalence has increased in the last decades worldwide leading to metabolic complications, such as type 2 diabetes, steatosis, cardiovascular disease, among others; its development is influenced by genetic factors and environmental factors, such as intestinal microbiome. In Mexico, 33.3% of the adults present this disease. Obesity is defined as an excessive adipose tissue accumulation, provoking its dysfunction. Adipose tissue remodeling, which involves angiogenesis, hypoxia and inflammation, is implicated in the developing of obesity and metabolic modifications. Bariatric surgery is the most used and successful intervention to control morbid obesity, leading a maintained loss of weight and remission of some of its comorbidities as type 2 diabetes. Here, we review some of the molecular aspects of the metabolic changes provoked by bariatric surgery and its impact in weight loss and comorbidities remission. In summary, this article reviews the genetic aspects, microbiome and molecular facts (adipose tissue remodeling) that are involved in obesity development. In addition, some of the molecular aspects about bariatric surgery are described and the mechanisms that are regulated to control obesity and its comorbidities.

Continuous quality improvement program and its results of Korean Society for Cytopathology

Since 1995, the Korean Society for Cytopathology has overseen the Continuous Quality Improvement program for cytopathology laboratories. The Committee of Quality Improvement has carried out an annual survey of cytology data for each laboratory and set standards for proficiency tests. Methods: Evaluations were conducted four times per year from 2008 to 2018 and comprised statistics regarding cytology diagnoses of previous years, proficiency tests using cytology slides provided by the committee, assessment of adequacy of gynecology (GYN) cytology slides, and submission of cytology slides for proficiency tests. Results: A total of 206 institutes participated in 2017, and the results were as follows. The number of cytology tests increased from year to year. The ratio of liquid-based cytology in GYN gradually decreased, as most of the GYN cytology had been performed at commercial laboratories. The distribution of GYN diagnoses demonstrated nearly 3.0% as atypical squamous cells. The rate for squamous cell carcinoma was less than 0.02%. The atypical squamous cell/squamous intraepithelial lesion ratio was about 3:1 and showed an upward trend. The major discordant rate of cytology-histology in GYN cytology was less than 1%. The proficiency test maintained a major discordant rate less than 2%. The rate of inappropriate specimens for GYN cytology slides gradually decreased. Conclusions: The Continuous Quality Improvement program should be included in quality assurance programs. Moreover, these data can contribute to development of national cancer examination guidelines and facilitate cancer prevention and treatment.

Initial Serum Ammonia as a Predictor of Mortality in Patients with Acute Glufosinate Ammonium Herbicide Poisoning

Purpose@#The association of the initial serum ammonia level with in-hospital mortality in patients with acute glufosinate-ammonium herbicide poisoning was studied. @*Methods@#This retrospective cohort study was conducted between March 2012 and August 2019 in the emergency department after glufosinate-ammonium herbicide poisoning. Survivors and non-survivors were analyzed using a Mann-Whitney U test and Fisher’s exact test. Multivariate logistic regression analysis was performed to determine the independent risk factors for mortality. @*Results@#One hundred and six patients were enrolled; 11 died, yielding a mortality of 10.4%. The serum bicarbonate level was significantly lower in the non-survival group than the survival group. Age, serum ammonia, blood urea nitrogen, creatinine levels, SOFA score, and APACHE II score were significantly higher in the non-survival group than the survival group. Age, serum ammonia, and creatinine level were independent risk factors for mortality in multivariate logistic regression analysis. @*Conclusion@#The initial serum ammonia level is associated with mortality in patients with acute glufosinate herbicide poisoning.

Initial Serum Ammonia as a Predictor of Mortality in Patients with Acute Glufosinate Ammonium Herbicide Poisoning

Purpose@#The association of the initial serum ammonia level with in-hospital mortality in patients with acute glufosinate-ammonium herbicide poisoning was studied. @*Methods@#This retrospective cohort study was conducted between March 2012 and August 2019 in the emergency department after glufosinate-ammonium herbicide poisoning. Survivors and non-survivors were analyzed using a Mann-Whitney U test and Fisher’s exact test. Multivariate logistic regression analysis was performed to determine the independent risk factors for mortality. @*Results@#One hundred and six patients were enrolled; 11 died, yielding a mortality of 10.4%. The serum bicarbonate level was significantly lower in the non-survival group than the survival group. Age, serum ammonia, blood urea nitrogen, creatinine levels, SOFA score, and APACHE II score were significantly higher in the non-survival group than the survival group. Age, serum ammonia, and creatinine level were independent risk factors for mortality in multivariate logistic regression analysis. @*Conclusion@#The initial serum ammonia level is associated with mortality in patients with acute glufosinate herbicide poisoning.

Is the National Early Warning Score applicable to patients with trauma?

OBJECTIVE@#The National Early Warning Score (NEWS) is used widely to detect deteriorating patients in a range of clinical situations. This study examined the ability of the NEWS to predict poor outcomes in trauma patients.@*METHODS@#This was a retrospective observational study using a dataset collected prospectively from trauma patients who visited the emergency department of a tertiary referral center in the southern area of the Republic of Korea. The area under the receiver operating curves (AUC) of the Revised Trauma Score (RTS) and NEWS were compared. The primary outcome was in-hospital mortality.@*RESULTS@#Among 17,661 patients finally enrolled, 66.3% were male, and the median age was 49 (34-64). The AUC of the NEWS and RTS were 0.878 (95% confidence interval [CI], 0.873–0.883) and 0.827 (95% CI, 0.821–0.833) (AUC difference, 0.051; 95% CI, 0.025–0.077; P<0.01), respectively. The sensitivity and specificity of the NEWS were 74.0% and 91.2%, respectively, at a cutoff of four, and those of the RTS were 67.7% and 96.1%, respectively, at 7.55.@*CONCLUSION@#The NEWS showed better performance in predicting the in-hospital mortality of patients with trauma compared to the RTS.

Multiple Metachronous Malignancies: One Patient with Five Primary Malignancies / 대한내과학회지

We report a case of a 73-year-old male with multiple, metachronous primary malignancies. He presented with adenocarcinoma of the stomach with transverse colon invasion followed by bladder cancer, hypopharyngeal cancer, urothelial cancer, and hepatocellular carcinoma, in that order, over 10 years. While these multiples malignancies were separate entities, they shared several etiologic factors, including smoking. To the best of our knowledge, this is the first description of five metachronous malignancies in a Korean patient.

Performance of the combined models of Pediatric Risk of Admission scores I and II, and C-reactive protein for prediction of hospitalization in febrile children who visited the emergency department

PURPOSE: To study the performance of the combined models of Pediatric Risk of Admission (PRISA) scores I and II and Creactive protein (CRP) for prediction of hospitalization in febrile children who visited the emergency department.METHODS: We reviewed febrile children aged 4 months-17 years who visited a tertiary hospital emergency department between January and December 2017. White blood cell count, CRP concentration, the PRISA scores, and systemic inflammatory response syndrome score were calculated. We compared areas under the curves (AUCs) of the admission decision support tools for hospitalization using receiver operating characteristic curve analysis.RESULTS: Of 1,032 enrolled children, 423 (41.0%) were hospitalized. CRP and the PRISA scores were significantly higher in the hospitalization group than in the discharge group (all P < 0.001). Among the individual tools, CRP showed the highest AUC (0.69; 95% confidence interval [CI], 0.66–0.72). AUC was 0.71 (95% CI, 0.69–0.74) for the combined model of the PRISA I score and CRP, and 0.71 (95% CI, 0.68–0.74) for that of the PRISA II score and CRP. The AUC of PRISA score I and CRP combined was significantly higher than that of isolated CRP (P = 0.048).CONCLUSION: The combined model of the PRISA I score and CRP may be useful in predicting hospitalization of febrile children in emergency departments.

Comparison of radiation exposure by area before and after emergency center remodeling

OBJECTIVE: Radiation is used extensively in emergency centers. Computed tomography and X-ray imaging are used frequently. Portable X-rays, in particular, cause a significant amount of indirect radiation exposure to medical personnel. The authors' emergency center was remodeled, and a comparative study of radiation exposure was carried out in certain places that had experienced radiation for a long time. METHODS: The cumulative radiation dose was measured 20 times in the 24 hours prior to remodeling, and the cumulative radiation dose was measured again 20 times across the 24-hour period. The measurement points were fixed at the emergency doctor's seat (Zone A), charge nurse's seat (Zone B), and section nurse's seat (Zone C). During the 24-hour cumulative radiation measurement period, the number of portable X-ray shots was recorded in the emergency center. RESULTS: The mean of the 24-hour cumulative radiation measurements in zone A was 3.36±0.07 µSV and 4.54±0.07 µSV before and after remodeling, respectively (P<0.001). Regarding the number of portable X-rays performed during the measurement, a higher number of trials in the Pearson correction correlated with a higher radiation measurement. CONCLUSION: In an emergency medical center, there is a higher level of low-dose radiation exposure compared to that experienced from natural radioactivity. Regarding the number of portable X-rays, the cumulative radiation dose measured 24 hours after remodeling increased and can be assumed to be related to the environment.

Comparison of acute phase reactant levels of Kawasaki disease patients who visited with less than 5 days duration of fever and with 5 days or longer

PURPOSE: Kawasaki disease (KD) is a common, acute systemic vasculitis in children. Acute phase reactants (APRs) have been used to assist diagnosis, and to predict outcome in children with KD. However, it remains unknown on levels of APRs depending on duration of fever. We aimed to compare APR levels of children with KD who visited with < 5 days duration of fever and with ≥ 5 days. METHODS: Children (≤ 15 years) with complete KD who visited the emergency department were enrolled from March 2012 through February 2018. The children were divided into the early (fever < 5 days) and late (fever ≥ 5 days) presenters. The baseline characteristics, APR levels, such as platelet count, and outcomes were compared between the 2 groups. RESULTS: A total of 145 children with complete KD were enrolled. Median age was 27.0 (interquartile range [IQR], 12.0–46.5) months, and boys accounted for 60.0%. The early presenters (63 [43.4%]) had a younger age (17.0 [IQR, 7.0–45.0] vs. 32.5 [IQR, 14.0–48.0] months; P = 0.006), shorter duration of fever (3.0 [IQR, 2.0–4.0] vs. 6.0 [IQR, 5.0–7.0] days; P < 0.001), and a lower platelet count (336.7 ± 105.2 [× 10³/µL] vs. 381.6 ± 121.8 [× 10³/µL], P = 0.02) than the late presenters. The other APR levels, and frequency of resistance to intravenous immunoglobulin and coronary artery abnormalities showed no differences between the 2 groups. CONCLUSION: Children with KD who visited with < 5 days duration of fever had a lower platelet count compared to those with ≥ 5 days. No differences were found in the other APR levels and the outcomes. It may be necessary to consider the differences in APR levels depending on duration of fever when treating children with KD.

Multiple Metachronous Malignancies: One Patient with Five Primary Malignancies / 대한내과학회지

We report a case of a 73-year-old male with multiple, metachronous primary malignancies. He presented with adenocarcinoma of the stomach with transverse colon invasion followed by bladder cancer, hypopharyngeal cancer, urothelial cancer, and hepatocellular carcinoma, in that order, over 10 years. While these multiples malignancies were separate entities, they shared several etiologic factors, including smoking. To the best of our knowledge, this is the first description of five metachronous malignancies in a Korean patient.

The Effect of Intravenous Lipid Emulsion in a Rat Model of Verapamil Toxicity

PURPOSE: Intravenous lipid emulsion (ILE) has been shown to have significant therapeutic effects on calcium channel blocker overdose in animal studies and clinical cases. In this preliminary experiment, we investigated the hemodynamic changes and survival in a rat model of verapamil intoxication. METHODS: Fourteen male Sprague-Dawley rats were sedated and treated with ILE or normal saline (control), followed by continuous intravenous infusion of verapamil (20 mg/kg/h). Mean arterial pressure and heart rate of rats were monitored during the infusion. In addition, the total dose of infused verapamil and the duration of survival were measured. RESULTS: Survival was prolonged in the ILE group (32.43±5.8 min) relative to the control group (24.14±4.3 min) (p=0.01). The cumulative mean lethal dose of verapamil was higher in the ILE group (4.3±0.7 mg/kg) than in the control group (3.2±0.5 mg/kg; p=0.017). CONCLUSION: ILE pretreatment prolonged survival and increased the lethal dose in a rat model of verapamil poisoning.

Coexistence of metastatic thyroid cancer and tuberculosis in a single neck lymph node: a rare association

No abstract available.

Therapeutic effect of ascorbic acid on dapsone-induced methemoglobinemia in rats

OBJECTIVE: Dapsone (diaminodiphenyl sulfone, DDS) is currently used to treat leprosy, malaria, dermatitis herpetiformis, and other diseases. It is also used to treat pneumocystis pneumonia and Toxoplasma gondii infection in HIV-positive patients. The most common adverse effect of DDS is methemoglobinemia from oxidative stress. Ascorbic acid is an antioxidant and reducing agent that scavenges the free radicals produced by oxidative stress. The present study aimed to investigate the effect of ascorbic acid in the treatment of DDS induced methemoglobinemia. METHODS: Male Sprague-Dawley rats were divided into three groups: an ascorbic acid group, a methylene blue (MB) group, and a control group. After DDS (40 mg/kg) treatment via oral gavage, ascorbic acid (15 mg/kg), MB (1 mg/kg), or normal saline were administered via tail vein injection. Depending on the duration of the DDS treatment, blood methemoglobin levels, as well as the nitric oxide levels and catalase activity, were measured at 60, 120, or 180 minutes after DDS administration. RESULTS: Methemoglobin concentrations in the ascorbic acid and MB groups were significantly lower compared to those in the control group across multiple time points. The plasma nitric oxide levels and catalase activity were not different among the groups or time points. CONCLUSION: Intravenous ascorbic acid administration is effective in treating DDS-induced methemoglobinemia in a murine model.