Endotype and Phenotype Related Postoperative Effects of Bacterial Lysate in Chronic Rhinosinusitis.

OBJECTIVES: Chronic rhinosinusitis (CRS) endotypes have demonstrated clinical value in guiding treatment decisions. Bacterial lysates are immunomodulators that have shown beneficial effects in various respiratory inflammatory diseases. This study aimed to evaluate the effect of postoperative bacterial lysate therapy on different CRS endotypes. METHODS: Patients diagnosed with CRS who underwent endoscopic sinus surgery were recruited. Bacterial lysates were administered postoperatively for 10 days per month for 3 months to the experimental group comprising patients with a history of frequent upper respiratory infections without adverse reactions. The remaining participants were allocated to the control group. The results of the postoperative 3-, 6-, and 12-month assessments, including the modified Lund-Kennedy (mLK) endoscopic and Sinonasal Outcome Test (SNOT) 22 scores, for the groups were compared. The tissue samples obtained from the participants were evaluated to detect the presence of relevant inflammatory mediators. RESULTS: Among the 92 participants, 47 started bacterial lysate therapy 2 weeks after the surgery. The tissue cytokine profiles and clinical parameters, such as the disease severity and blood eosinophil percentage, of the bacterial lysate and control groups were comparable before treatment. The mLK endoscopic and SNOT-22 scores did not differ after 3, 6, and 12 months of follow-up. The subgroup analysis revealed that the bacterial lysate group had significantly lower mLK endoscopic scores than the control group for CRS without nasal polyps, while there was a tendency toward significance for the interleukin (IL)-5 negative group after 6 months. CONCLUSION: Postoperative bacterial lysate therapy has some beneficial effects on the endoscopic findings of patients with CRS without nasal polyps or those who are negative for IL-5.

The Role of Fractional Exhaled Nitric Oxide in Diagnosing Asthmatic Type 2 Chronic Rhinosinusitis With Nasal Polyps.

BACKGROUND: Fractional exhaled nitric oxide (FeNO) is useful in the management of asthma and predicting the efficacy of standard corticosteroids and biologics. However, the diagnostic value of FeNO in asthmatic chronic rhinosinusitis with nasal polyps (CRSwNP) remains unclear. OBJECTIVE: We assessed FeNO levels in patients with CRSwNP and evaluated the diagnostic value of FeNO for screening type 2 CRSwNP (T2-CRSwNP) with asthma. METHODS: We enrolled 94 patients who were diagnosed with CRSwNP and underwent functional endoscopic sinus surgery. FeNO levels, the blood eosinophil percentage, total IgE, spirometry tests (FEV1/FVC), Lund-Mackay CT score, and percentage of patients with comorbid asthma were compared among CRSwNP subgroups. Spearman rank correlation test was used to assess the degree of association between variables. ROC curve analysis was conducted to evaluate the diagnostic capability to differentiate T2-CRSwNP based on clinical and histological classifications. RESULTS: FeNO levels and the blood eosinophil percentage were significantly higher in patients with T2-CRSwNP(h) based on histological data (P < .05). FeNO was correlated with the blood eosinophil percentage (r = 0.420, P < .001) and FEV1/FVC (r = -0.324, P = .001). A FeNO level of 27 ppb had a good ability to discriminate patients with asthmatic T2-CRSwNP(h) (AUC = 0.848; 95% CI = 0.7602-0.9361; sensitivity = 90.9%; specificity = 63.9%). The optimal cutoff values for FeNO and the blood eosinophil percentage for diagnosing asthmatic T2-CRSwNP(h) were 68 ppb and 5.6% (sensitivity = 95.5%; specificity = 86.1%; AUC = 0.931; 95% CI = 0.8832-0.9791). In the diagnosis of severe T2-CRSwNP(c) based on clinical data, a FeNO level of 36 ppb showed the highest AUC (0.816; 95% CI = 0.7173-0.914; sensitivity = 72.7%; specificity = 79.2%). CONCLUSION: FeNO is a useful marker for screening asthmatic T2-CRSwNP even prior to biopsy or asthma evaluation and may assist in selecting a proper treatment.

Effects of Neutrophil and Eosinophil Extracellular Trap Formation on Refractoriness in Chronic Rhinosinusitis With Nasal Polyps.

PURPOSE: This study investigated the clinical implications of neutrophil extracellular trap (NET) formation (NETosis) and eosinophil extracellular trap (EET) formation (EETosis) regarding refractoriness in chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP). METHODS: Nasal polyp specimens were obtained from 117 patients with CRSwNP who received endoscopic sinus surgery. Disease control status at postoperative 1 year was assessed. Refractory cases were defined as partly controlled or uncontrolled cases according to the EPOS 2020 guidelines. NETosis and EETosis were evaluated through immunofluorescence staining (citrullinated histone H3-human neutrophil elastase and citrullinated histone-galectin-10, respectively) followed by manual counting. The z-score of NET and EET counts was used to define the following four groups: low extracellular trap formation (ETosis), NETosis-predominant, EETosis-predominant, and high-ETosis. RESULTS: The refractory and non-refractory groups showed significant differences in the tissue eosinophil count (P = 0.005) and EET count (P = 0.029). The tissue neutrophil count and the NET/neutrophil ratio were significantly different between the refractory and non-refractory groups of patients with neutrophilic CRS (P = 0.045, 0.031, respectively). Refractoriness significantly differed among the low-ETosis (30.77%), NETosis-predominant (47.83%), EETosis-predominant (56.67%), and high-ETosis (83.33%) groups (P = 0.005). CONCLUSIONS: The results of this study suggest that tissue Eosinophilia and EETosis may play a prognostic role, primarily in CRSwNP and thattissue neutrophilia and NETosis can play as prognostic biomarkers in neutrophilic CRSwNP.

Impact of the COVID-19 and Socioeconomic Status on Access to Care for Otorhinolaryngology Patients.

Since December 2019, COVID-19 has greatly influenced public healthcare systems around the globe in various aspects, including limitation of healthcare accessibility due to lack of both human and financial resources, suspension of clinics, and fear of infection causing healthcare avoidance. The aim of this study was to investigate the impact of COVID-19 on access to healthcare for otorhinolaryngology patients from different socioeconomic status (SES) groups. Otorhinolaryngology patients' disease severity status, diagnosed at the first hospital visit, was investigated during the pre -and post-COVID-19 pandemic era in a single medical center located in Seoul, Korea. An ordinal regression model was used to assess the impact of both SES and the COVID-19 pandemic on otorhinolaryngology diseases. Within the chronic rhinosinusitis group, lower SES was associated with a higher disease severity at the first visit compared to higher SES (OR = 3.25). During the COVID-19 pandemic, while the total number of outpatients was reduced, the severity of these ENT diseases seemed to increase compared to the pre-pandemic severity in every SES group. Our study demonstrates the negative impact a worldwide pandemic can have on healthcare inequity and disease severity, and highlights the importance of re-allocating fundamental resources for those in need during periods of public health crisis.

Alleviation of Surgery-Induced Osteitis in Sinonasal Cavity by Dexamethasone-Loaded Poly(lactic-co-glycolic acid) (PLGA) Microparticles with Strong Calcium-Binding Affinity.

For the treatment of sinus surgery-induced osteitis in chronic rhinosinusitis (CRS), oral or intranasal administration of corticoids is generally used, although it has critical limitations and unavoidable side effects. To overcome these limitations, we designed dexamethasone (Dex)-loaded poly(lactic-co-glycolic acid) (PLGA) microparticles with bone-specific binding affinity, which could release the encapsulated Dex in a sustained manner on the exposed bone after the surgical wound in the nasal cavity. In a previous report, we prepared poly(butyl methacrylate-co-methacryloyloxyethyl phosphate) (PBMP) with both calcium-binding phosphomonoester groups and PLGA-binding butyl groups to introduce strong calcium-binding property to PLGA particles. In this study, after successful encapsulation of Dex in the PBMP-coated PLGA particles, we applied the Dex-PLGA/PBMP to the treatment of post-operative osteitis in the sinonasal cavity. The Dex-PLGA/PBMP showed more than 5-times higher binding affinity to the hydroxyapatite (HA) surface compared to the non-coated PLGA particles, without altering the morphology and encapsulation efficiency. After establishing the neo-osteogenesis mouse model by mechanical injury of the nasal mucosa, the activity of intranasally administered Dex-PLGA/PBMP was examined to inhibit the formation of undesirable new woven bone during the wound healing process. In addition, significantly lower osteocalcin activity was observed in the group treated with Dex-PLGA/PBMP, indicating decreased activation of osteoblasts. Overall, these results demonstrate that the PLGA/PBMP microparticle strategy has great potential for the treatment of CRS-related osteitis by localized corticoid delivery on the exposed bones with minimal side effects.

Optimal application of soft-palate webbing flap pharyngoplasty combined with nasal surgery for surgical treatment of primary snoring and obstructive sleep apnea.

BACKGROUND: Excessive collapse of the soft palate and lateral pharyngeal wall narrowing are established causes of loud snoring and sleep apnea in subjects with obstructive sleep apnea (OSA). Therefore, delicate surgical techniques are needed to reshape the soft palate and create sufficient tension in the lateral pharyngeal wall. This study aimed to determine the therapeutic outcome and favorable indications of soft-palate webbing flap pharyngoplasty in subjects with OSA and primary snoring. METHODS: A total of 174 subjects who underwent soft-palate webbing flap pharyngoplasty combined with uvulopalatal flap and septoturbinoplasty from August 2015 to February 2020 were included in this study. Medical records, including pre- and postoperative sleep parameters, were retrospectively reviewed. The primary outcome measure was the degree of improvement in AHI after surgery. Other outcomes were differences in surgical response rates, subjective visual analog score (VAS) for snoring, sleep quality, and complications. RESULTS: Polysomnographic results showed that apnea-hypopnea index (AHI) scores were significantly reduced from 39.6 ± 6.1 to 22.9 ± 3.6 following soft-palate webbing flap pharyngoplasty in 59 subjects, and overall success and response rates of this technique were analyzed with 71%. We found that the successful outcomes were observed in 50% of mild (n = 12) and 56% of moderate (n = 16) subjects with OSA subjects due to lateral pharyngeal wall collapse. The success rate of soft-palate webbing flap pharyngoplasty was relatively higher in subjects with mild and moderate OSA than those with severe OSA. Additionally, the mean VAS snoring scale was 4.7 and subjects' primary snoring intensity significantly improved to 2.9 after soft-palate webbing flap pharyngoplasty. Subjective symptoms such as daytime sleepiness and sleep quality also showed improvement. Most complications were found to be minimal and improved by 1 month after the operation. CONCLUSION: Our data demonstrate that soft-palate webbing flap pharyngoplasty is an effective treatment for OSA and primary snoring and may be a promising technique to reduce lateral pharyngeal wall collapse.

Endotype-related recurrence pattern of chronic rhinosinusitis in revision functional endoscopic sinus surgery.

OBJECTIVE: The recurrence of chronic rhinosinusitis (CRS) after functional endoscopic sinus surgery (FESS) is influenced by various factors, potentially including the endotype based on the molecular pathophysiology of CRS. This study investigated differences in the recurrence pattern of CRS by endotype after primary FESS. METHODS: This retrospective study enrolled patients who had undergone revision FESS for recurrent CRS. Based on their clinical diagnosis, the patients were divided into two endotype groups: recurrent eosinophilic CRS (rECRS) and recurrent non-eosinophilic CRS (rNECRS). We compared and analyzed preoperative computed tomography (CT) findings, including typical anatomical findings of recurred CRS such as lateralized middle turbinate and retained uncinate process, the sinus where recurrence took place, and previous surgical completeness of the sinuses, between the rECRS and rNECRS groups. RESULTS: In total, 142 patients were enrolled (48 rECRS, 94 rNECRS). No significant difference was found in the typical anatomic findings of recurrent CRS between the rECRS and rNECRS groups. The rates of the completeness of previous surgeries was significantly higher in rECRS than in rNECRS(P=.031). Despite the completeness of previous surgeries, the recurrence rate of frontal and ethmoidal sinuses was higher in the rECRS than rNECRS(P=.012, P<.001, respectively). In subgroup analysis according to the severity of ECRS, the number of involved sinuses and the rates of CRS recurrence and surgical completeness in frontal and anterior ethmoidal sinuses increased with ECRS severity. CONCLUSIONS: CT findings of revision FESS cases differed by CRS endotype. The rECRS group showed higher recurrence in the frontal and ethmoidal sinuses despite a higher surgical completeness rate. Incomplete surgery was more often found in the rNECRS group.

Is Body Mass Index Related to Skin Reactivity to Histamine but not to Specific Allergens? A 2-Year Follow-up Study on Korean Children.

BACKGROUND: Skin prick tests are widely used to diagnose allergic sensitization. The influence of obesity on the skin prick test result has not been clearly established, even though the association between allergic disease and obesity is relatively well known. OBJECTIVE: To determine whether a change in body mass index (BMI) contributes to skin reactivity to histamine and allergens in a skin prick test, we performed a 2-year follow-up study on Korean children. METHODS: Skin prick tests for common aeroallergens were performed on elementary school students from Jeju Island, Korea. BMI was calculated using weight and height after measuring both, and demographic characteristics were surveyed. The same tests were repeated after 2 years. RESULTS: The sensitization rate increased during the 2 years between tests and the children's mean BMI also increased, along with their age. The wheal sizes induced by Dermatophagoides pteronyssinus, Dermatophagoides farinae, Japanese cedar, and histamine were significantly increased during 2 years; however, only the histamine reaction associated with increased BMI had statistical significance. Furthermore, other variables-including the number of sensitized allergens-were not related to histamine skin reactivity. CONCLUSION: Histamine skin reactivity increased in children over time and some allergens showed increased specific reactions; however, BMI gain is a specific predictor of histamine reactivity. Further studies are needed to elucidate the clinical significance of these changes.

Is Ossiculoplasty Necessary in Canal Wall Down Mastoidectomy? Comparison of Clinical Outcomes Between Type 0 Tympanoplasty and Ossiculoplasty.

BACKGROUND AND OBJECTIVES: To assess whether the audiological and clinical outcomes of type 0 tympanoplasty (T0) performed using cartilage were comparable with those of ossiculoplasty in patients who underwent canal wall down mastoidectomy (CWDM). SUBJECTS AND METHODS: This study included patients who had chronic otitis media with cholesteatoma and underwent CWDM with ossiculoplasty involving partial ossicular replacement prosthesis (PORP), total ossicular replacement prosthesis (TORP), or T0. Anatomical success rates and hearing outcomes were analyzed. RESULTS: Seventy-two patients were included in this study; 29 of them underwent CWDM with T0, 27 underwent CWDM with PORP, while 16 underwent CWDM with TORP. The difference in mean improvement in the air-bone gap (ABG) between the groups was not significant. The differences in the rates of ABG closure to ≤10 dB HL (p=0.030) and ≤20 dB HL (p=0.029) were significant. There were significant differences in improvements in the ABG at 3 kHz among the PORP, TORP, and T0 groups. CONCLUSIONS: The audiological outcomes of CWDM with ossiculoplasty seemed to be better than those of CWDM with T0 with no significant difference in the incidence of complications following ossiculoplasty and T0.

In vivo Application of the REMOTE-control System for the Manipulation of Endogenous Gene Expression.

Here we describe a protocol for implementing the REMOTE-control system (Reversible Manipulation of Transcription at Endogenous loci), which allows for reversible and tunable expression control of an endogenous gene of interest in living model systems. The REMOTE-control system employs enhanced lac repression and tet activation systems to achieve down- or upregulation of a target gene within a single biological system. Tight repression can be achieved from repressor binding sites flexibly located far downstream of a transcription start site by inhibiting transcription elongation. Robust upregulation can be attained by enhancing the transcription of an endogenous gene by targeting tet transcriptional activators to the cognate promoter. This reversible and tunable expression control can be applied and withdrawn repeatedly in organisms. The potency and versatility of the system, as demonstrated for endogenous Dnmt1 here, will allow more precise in vivo functional analyses by enabling investigation of gene function at various expression levels and by testing the reversibility of a phenotype.

Computed Tomography Findings in Patients with Samter's Triad: An Observational Study.

Samter's Triad is a disorder characterized by chronic rhinosinusitis (CRS) with nasal polyps (NPs), asthma, and intolerance to cyclooxygenase-1 inhibitors. However, there have been no studies investigating the prediction of Samter's Triad using imaging findings. Therefore, the authors aimed to investigate whether there is a difference in computed tomography (CT) findings between patients who have CRS with NPs and those with Samter's Triad. Patients were classified into a CRS group and a Samter group. Opacification was measured using data from CT scans by scoring each sinus on a numerical rating scale ranging from 0 to 4. The opacification scores of the ethmoid and frontal sinuses were significantly higher in the Samter's Triad group. Furthermore, Samter's Triad was more common in patients who scored ≤ 2 for maxillary opacification (7/16) than in those who scored ≥3 (4/45, p=0.005). Patients with Samter's Triad exhibited a tendency toward higher opacification scores for the ethmoid and frontal sinuses, with a relatively lower opacification score for the maxillary sinus. These findings could be helpful in distinguishing patients with Samter's Triad from those who have CRS with NPs, and to plan treatment strategies without having to perform additional laboratory or radiological tests.

Hazardous Alcohol Consumption and the Risk of Hearing Impairment in Adults Based on the Korean National Health and Nutrition Survey: A Retrospective Study.

BACKGROUND AND OBJECTIVES: To investigate the relationship between hearing impairment and alcohol drinking patterns in South Korean adults. SUBJECT AND METHODS: Data collection was performed by Korean National Health and Nutrition Survey from January 1 to December 31, 2012. Data analyses were performed from February 20 to March 3, 2018. Data from 3,860 adults 20 years of age or older without a history of malignancy or chronic otitis media in the Korean National Health and Nutrition Survey 2012 database who participated in the health questionnaires, and who had available results from otologic examinations that included pure tone audiogram, were included. Pure-tone average hearing thresholds were calculated at 500, 1,000, 2,000, and 4,000 Hz. Hearing loss was defined as a pure-tone average >40 dB in one or both ears. The Alcohol Use Disorder Identification Test was used to evaluate drinking statuses of subjects. Data were analyzed using the complex-sample χ2 -test of independence and a complex-sample logistic regression analysis. RESULTS: Of the 29,954,319 individuals in the weighted cross-sectional study population, 15,106,040 (50.4%) were men and 14,848,098 (49.6%) were women. A total of 8.1% of men and 7% of women had hearing impairment. The degrees of drinking with appropriate, risky, and hazardous drinking habits were 58.2, 32.1, and 9.7% among men; and 76.4, 12.5, and 11.1% among women, respectively. Among men, the odds ratio of hearing loss increased by 2.506 times when comparing hazardous and appropriate drinking (confidence interval, 1.083 to 5.800, p=0.002). Moderate alcohol consumption (≤2 drinks per day) was not protective for hearing in either group. CONCLUSIONS: As hazardous drinking tends to coexist with hearing impairment in men, appropriate prevention and intervention strategies should be emphasized. A longitudinal study to investigate harmful drinking and the mechanism of hearing loss should be performed.

Chronological changes in rhinitis symptoms present in school-aged children with allergic sensitization.

INTRODUCTION: It is difficult to accurately predict the natural course of allergic rhinitis (AR), because it is affected by a wide variety of environmental influences, as well as genetic predisposition. Considering the high prevalence of allergic rhinitis in children and adolescents, caregivers should be given appropriate information regarding the disease course. This study aimed to understand the prognosis of allergic rhinitis by examining the relationship between allergic sensitization and rhinitis symptoms during this developmental period. METHODS: This cross-sectional study included 1069 children aged 9-16 years from the Korean International Study of Asthma and Allergies in Childhood Survey database who had completed health questionnaires, and for whom skin prick test results were available. Data were collected during May 2016. The distribution of sensitization and allergic symptoms was compared by age groups (elementary, middle, and high school). Data were analyzed using linear-by-linear analysis. RESULTS: Sensitization to at least one tested allergen differed by age (59.2%, 58.3%, 68.2%, in elementary, middle, and high school students, respectively; p = 0.025), and seasonal allergen sensitization (35.0%, 37.1%, 53.9%, respectively) increased with age (p < 0.001). Conversely, the proportion of rhinitis symptoms among sensitized children decreased as age increased (58.80%, 52.90%, 49.70%, respectively; p = 0.047). However, the rate of non-allergic rhinitis was age-independent. CONCLUSION: With increasing age during childhood and adolescence, symptomatic allergic rhinitis decreases; thus, subclinical allergic rhinitis increases. This suggests that the symptoms of later-sensitized children are less clearly manifested, or that the symptoms reduce as previously sensitized children mature. This should be clarified further in a longitudinal study.

Comparison of clinical outcomes between butterfly inlay cartilage tympanoplasty and conventional underlay cartilage tympanoplasty.

OBJECTIVE: To assess the efficacy of butterfly inlay cartilage tympanoplasty and compare it with conventional underlay cartilage tympanoplasty in terms of success rate and hearing outcomes. MATERIALS AND METHODS: The study included 35 patients (36 ears) who underwent butterfly inlay cartilage tympanoplasty (inlay group, 23 ears of 22 patients) or conventional underlay cartilage tympanoplasty (underlay group, 13 ears). The anatomical success rate and hearing outcomes were analysed. RESULTS: Re-perforation occurred in 2 cases (8.7%) in the inlay group and 3 (23.1%) in the underlay group. One patient in the inlay group developed a serious infection, and one in the underlay group developed massive granulation of the tympanic membrane. In the inlay group, the air-bone gap (ABG) decreased from 19.9 (±12.6) dB HL preoperatively to 13.8 (±11.3) dB HL postoperatively (p=0.047), in the underlay group, it decreased from 23.5 (±15.8) dB HL to 18.3 (±20.6) dB HL. Regarding improvement in ABG, the difference between the group was not statistically significant (p=0.968). CONCLUSION: Butterfly inlay cartilage tympanoplasty is comparable with conventional underlay cartilage tympanoplasty in both anatomic and audiological success rates. Owing to its simplicity, shorter operation time, and rapid patient recovery, butterfly inlay cartilage tympanoplasty could be considered a favourable surgical option.

Effect of Rufinamide on the kainic acid-induced excitotoxic neuronal death in the mouse hippocampus.

Rufinamide (RUF) is a structurally unique anti-epileptic drug, used in the treatment of seizure disorders such as Lennox-Gastaut syndrome. In the present study, we investigated whether RUF protected against excitotoxic neuronal damage in the mouse hippocampal CA3 region after intraperitoneal kainic acid (KA) injection. Treatment with 25, 50 and 100 mg/kg RUF significantly decreased the KA-induced neuronal death in the hippocampal CA3 region in a dose-dependent manner. In addition, 100 mg/kg RUF treatment reduced the KA-induced oxidative stress-related increase of MDA level and decrease of total SOD activity in the hippocampus. KA-induced increases of pro-inflammatory cytokines, TNF-α and IL-1ß, levels as well as KA-induced microglial activation were also suppressed by RUF treatment. These results indicate that RUF displays a neuroprotective effect against KA-induced excitotoxic neuronal death in the mouse hippocampus through anti-oxidant and anti-inflammatory activities.

Simultaneous determination of clanobutin, dichlorvos, and naftazone in pork, beef, chicken, milk, and egg using liquid chromatography-tandem mass spectrometry.

A chromatographic method involving a single run was validated for the quantification of clanobutin, dichlorvos, and naftazone in products of animal origin. Pork, beef, chicken, milk, and egg samples were extracted with a solution of 0.1% formic acid in acetonitrile, defatted with n-hexane, centrifuged, and filtered prior to analysis using liquid chromatography-tandem mass spectrometry (LC-/MS/MS). The analytes were separated on a C18 column using a solution of 0.1% formic acid and 10 mM ammonium formate (A) and acetonitrile (B) as the mobile phase. A good linearity over 5-50 ng/g concentration range was obtained with coefficients of determination (R2) ≥ 0.9807. The intra- and interday accuracy (recovery %) calculated from 3 fortification levels (5, 10, and 20 ng/g) were 73.2-108.1% and 71.4-109.8%, and the precisions (expressed relative standard deviations (RSDs)) were 0.9-12.9% and 1.8-10.6%, respectively, for the 3 tested analytes in animal originated foods. The limits of quantification (LOQs) ranged between 0.1 and 1 ng/g, thus enabling the quantification of residual levels below the uniform maximum residue limit (MRL) of 0.01 mg/kg set for compounds having no MRL. The designated methodology was successfully applied to monitor various samples collected from Seoul; the tested analytes were not quantified in any of the market samples. Conclusively, the developed method is simple, sensitive, and accurate, and could be used for the detection of pharmaceuticals in various animal food matrices with variable protein and fat contents.

Determination of metoserpate, buquinolate, and diclofenac in pork, eggs, and milk using liquid chromatography-tandem mass spectrometry.

In this work, a method was developed for the simultaneous determination of residual metoserpate, buquinolate and diclofenac in pork, milk, and eggs. Samples were extracted with 0.1% formic acid in acetonitrile, defatted with n-hexane, and filtered prior to analysis using liquid chromatography-tandem mass spectrometry. The analytes were separated on a C18 column using 0.1% acetic acid and methanol as the mobile phase. The matrix-matched calibration curves showed good linearity over a concentration range of 5-50 ng/g with coefficients of determination (R2 ) ≥0.991. The intra- and inter-day accuracies (expressed as recovery percentage values) calculated using three spiking levels (5, 10, and 20 µg/kg) were 80-108.65 and 74.06-107.15%, respectively, and the precisions (expressed as relative standard deviation) were 2.86-13.67 and 0.05-11.74%, respectively, for the tested drugs determined in various matrices. The limits of quantification (1 and 2 µg/kg) were below the uniform residual level (0.01 mg/kg) set for compounds that have no specific maximum residue limit (MRL). The developed method was tested using market samples and none of the target analytes was detected in any of the samples. The validated method proved to be practicable for detection of the tested analytes in pork, milk, and eggs.