Higher exposure to 1,3-butadiene is associated with more severe hearing loss.

While volatile organic compounds (VOCs) impair various organs, their influence on hearing loss (HL) has not been extensively researched. We aimed to identify the association between VOCs and HL or high-frequency hearing loss (HFHL). We extracted data on age, sex, pure tone audiometry, hypertension, occupational noise exposure, and creatinine-corrected urine VOC metabolite concentrations from the eighth Korea National Health and Nutrition Survey. Among the VOC metabolites, N-acetyl-S-(benzyl)-L-cysteine (BMA, P = 0.004), N-acetyl-S-(phenyl)-L-cysteine (SPMA, P = 0.027), and N-acetyl-S-(3,4-dihydroxybutyl)-L-cysteine (DHBMA, P < 0.001) showed associations with HL. Additionally, HFHL exhibited significant associations with BMA (P = 0.005), 3- and 4-methylhippuric acid (3, 4 MHA, P = 0.049), mandelic acid (MA, P = 0.015), SPMA (P < 0.001), N-acetyl-S-(3-hydroxypropyl)-L-cysteine (3-HPMA, P < 0.001), and DHBMA (P < 0.001). After controlling other factors, DHBMA were associated with HL (P = 0.021) and HFHL (P = 0.014) and exhibited a linear association with the mean hearing level (ß = 0.054, P = 0.024) and high-frequency hearing level (ß = 0.045, P = 0.037). Since 1,3-butadiene may act as an ototoxic material, early screening for workers exposed to 1,3-butadiene and reducing exposure to 1,3-butadiene in everyday life may be helpful to prevent further HL.

Insufficient nutrient intake in individuals with disabling hearing loss and the restoration of nutritional sufficiency in hearing aid users.

Hearing loss affects some nutrient intake. Disabling hearing loss may exacerbate these issues. We aimed to evaluate nutrient intake and assess deficiencies based on functional hearing status. The study included 6907 participants with information on demographic factors, nutrient intake, weight, height, disease status, and hearing level in the eighth Korea National Health and Nutrition Examination Survey, conducted from 2019 to 2021. We categorized the participants into 3 groups based on their functional hearing status: bilateral hearing, unilateral hearing, and disabling hearing loss. The disabling hearing loss group showed lower intake of most major nutrients (P < 0.05), dietary fiber (P < 0.001), and most minerals and vitamins (P < 0.05), with some insufficiencies. The unilateral hearing group showed lower intake only for potassium (P = 0.036) compared to the bilateral hearing group and significantly higher intake of hydration (P = 0.039), dietary fiber (P = 0.039), and calcium (P = 0.009) than the disabling hearing loss group. Nutrient insufficiency in the disabling hearing loss group was more prominent in women, and was partially resolved by using hearing aids. Clinicians and nutritionists should consider undernourishment in these patients, and appropriate interventions for nutrition and hearing aids should be recommended.

Microalbuminuria and Functional Iron Deficiency are Risk Factors for Hearing Loss in Adolescents.

OBJECTIVES: Renal impairment and some systemic diseases are associated with hearing loss (HL) in adults. However, studies of these relationship in adolescents are rare. The objective of this study was to determine the association between HL and renal or systemic disease in adolescents. METHODS: Subjects were extracted from the 5th Korea National Health and Nutrition Examination Survey from 2011 to 2012. We included adolescents aged 10-19 years old with normal tympanic membrane and those who underwent a physical and laboratory examination and pure tone audiometry. HL, high-frequency hearing loss (HFHL), albuminuria, impaired glomerular filtration rate, hypertension, diabetes, and obesity were evaluated based on the data. RESULTS: Individuals with microalbuminruia (MIA) exhibited higher prevalence of HL (p = 0.003) and HFHL (p = 0.012) than those without MIA. The prevalence of HL and HFHL appeared to increase according to the severity of albuminuria. Additionally, individuals with HL or HFHL showed lower transferrin saturation (TSAT) than individuals without HL (p = 0.002) or HFHL (p = 0.001). And, HFHL was associated with lower ferritin levels (p = 0.017). HL and HFHL were related to MIA (p = 0.004 and p = 0.022, respectively) and TSAT (p = 0.005 and p = 0.011, respectively) after controlling other factors. CONCLUSION: MIA and TSAT level were independently associated with the HL and HFHL. Since MIA can be easily detected by dipstick test and urine analysis, hearing evaluations for individuals with MIA might be helpful to identify hearing impairments earlier in adolescents. LEVEL OF EVIDENCE: 3 (individual cross-sectional study) Laryngoscope, 2024.

Effects of Economic Status on Changes in Social Networks and Mental Health after Using Hearing Aids.

OBJECTIVES: Hearing impairment affects social networks and mental health. Hearing aids (HA) can improve these deficits. However, their effects might be affected by various factors such as economic status (ES). This study aimed to identify how ES could moderate the effects of HA on social networks, depressive mood, and cognition. METHODS: A prospective cohort for new HA users was established and classified into two groups based on their ES: a low ES group (LES group) and a medium to high ES group (MHES group). Audiological examination, Lubben social network scale-18 (LSNS-18), Short form of Geriatric Depression Score, Mini-Mental State Examination in the Korean version of the CERAD Assessment Packet, and surveys for satisfaction with HA were conducted before and at six months after wearing HA. RESULTS: Post-HA application LSNS-18 scores were not improved in the LES group whereas they revealed significant improvement in the MHES group (p = 0.003). The LES group showed lower LSNS-18 score (p = 0.020) and its change (p = 0.042) than the MHES group. Additionally, patients with depressive moods in the MHES group showed better improvements than those in the LES group (p = 0.048). The effects of wearing HA on cognition and satisfaction with HA were not significantly different between the two groups. CONCLUSIONS: HA did not improve social relationships and depressive moods in the LES group. Comprehensive and multidirectional support as well as hearing rehabilitation may be important for patients with LES. LEVEL OF EVIDENCE: 3 (Nonrandomized controlled cohort/follow-up study) Laryngoscope, 134:2387-2394, 2024.

Investigating factors influencing post-operative growth in pre-pubertal children after adenotonsillectomy.

PURPOSE: To check the change in growth-for-age after adenotonsillectomy in pre-pubertal children and investigate the affecting factors. METHODS: Two hundred and six pediatric patients who underwent adenotonsillectomy by a single surgeon between January 2011 and December 2014 were included for the retrospective cohort study. The z-scores of height-, weight-, and body mass index (BMI)-for-age were measured before adenotonsillectomy and 1 year after the operation. The Korean version of the obstructive sleep apnea-18 questionnaire (OSA-18), symptom questionnaire, physical examinations, demographic data, and pre-operative z-scores were used to analyze the factors affecting z-score change. RESULTS: Among 206 pediatric patients, 167 patients were normal growth; 19 were undergrowth; and 20 were obese. After the operation, height, weight, and BMI z-scores all increased both in 167 normal-growth patients and 19 undergrowth patients (p value < 0.05). However, in 20 obese patients, only height z-score significantly increased (p value = 0.028). The multiple regression test showed that the sleep disturbance domain of OSA-18 was positively correlated with height z-score change (p value = 0.041), and age was negatively correlated with weight z-score change (p value = 0.016). Pre-operative BMI z-score was negatively correlated (p value = 0.019) and adenoid grade was positively correlated (p value = 0.023) with BMI z-score change. CONCLUSIONS: These findings suggest that adenotonsillectomy may positively affect growth in pre-pubertal children, without undesirable weight gain. Additionally, the sleep disturbance domain of OSA-18 may play a role in predicting post-operative height increase in pre-pubertal children.

Neurocognition of Aged Patients With Chronic Tinnitus: Focus on Mild Cognitive Impairment.

OBJECTIVES: To investigate the neurocognition of aged patients with chronic tinnitus and reveal the possible association between tinnitus severity and cognitive function, with attention to mild cognitive impairment (MCI). METHODS: Fifty-eight elderly patients (≥65 years old) with chronic tinnitus (≥6 months) were prospectively enrolled in this study. All patients assessed the neurocognitive batteries including the Korean version of the patient health questionnaire-9 (K-PHQ-9), the Lawton instrumental activities of daily living scale (K-IADL), and the Montreal cognitive assessment (MoCA-K). After initial evaluation to exclude moderate or severe cognitive impairment by a psychiatrist, the patients were classified into two groups: MCI and non-MCI, according to the MoCA-K scores (cutoff value, 22/23). All patients underwent audiological examinations including psychoacoustic tests of tinnitus. RESULTS: Of 58 patients, 10 (17.2%) met the MCI criteria. The tinnitus handicap inventory (THI) score in the MCI group was significantly higher than that in the non-MCI group. Based on multivariate regression analysis, a significant association between tinnitus severity and MoCA-K score was also detected. Specifically, bothersome tinnitus (THI score ≥30) was closely linked to the presence of MCI. Meanwhile, the impact of MCI on both K-PHQ-9 and K-IADL scores was not evident in patients with chronic tinnitus. CONCLUSION: Tinnitus severity appears to be a potential independent determinant for predicting the MCI, suggesting the underlying mechanism between chronic tinnitus and cognitive deficit. Given that MCI highly links to dementia, the evaluation of cognitive functions in aged patients with chronic tinnitus need to be considered at the initial assessment of tinnitus.

Indications for and Outcomes of Expansion Sphincter Pharyngoplasty to Treat Lateral Pharyngeal Collapse in Patients With Obstructive Sleep Apnea.

IMPORTANCE: The lateral pharyngeal wall is recognized as an important site of upper airway collapse during sleep in patients with obstructive sleep apnea (OSA), and expansion sphincter pharyngoplasty (ESP) may have promising clinical utility in patients with OSA and lateral pharyngeal wall collapse. OBJECTIVES: To evaluate the therapeutic outcomes of ESP in conjunction with other surgical procedures and to investigate indications for ESP in patients with OSA. DESIGN, SETTING, AND PARTICIPANTS: Cohort study of 63 patients with OSA diagnosed with lateral pharyngeal collapse under drug-induced sleep endoscopy who underwent ESP combined with tonsillectomy, uvuloplasty, or nasal surgery at Seoul National University Hospital in Seoul, Korea, between March 1, 2015, and December 1, 2016. MAIN OUTCOMES AND MEASURES: The primary outcome measure was the change in the apnea-hypopnea index (AHI) after surgery (AHI represents the number of apnea-hypopnea events per hour). Other outcome measures were differences in the surgical response rates, lowest oxygen saturation, subjective visual analog scale scores for snoring and apnea, and Epworth Sleepiness Scale score. RESULTS: Fifty of the 63 patients (79%) were male; the mean age was 42.1 (range, 20-54) years, and the mean body mass index (calculated as weight in kilograms divided by height in meters squared) was 27.6 (range, 19.0-32.1). Expansion sphincter pharyngoplasty was performed in patients with OSA with an AHI greater than 15 events per hour, more than 75% retropalatal circumferential narrowing when awake, and narrowed oropharynx due to bulky soft tissue around the lateral pharyngeal wall. In 42 of the 63 patients (67%), ESP was objectively successful in correcting lateral pharyngeal collapse; there was a significant reduction in mean AHI from 35.5 to 17.3 (mean difference, 18.1; 95% CI, 16.3-20.0) and improvement of the lowest mean (SD) oxygen saturation measurement from 78.2% (21.3%) to 86.4% (10.6%) (mean difference, 8.60%; 95% CI, 6.60%-10.60%) 6 months after the operation. The rate of postoperative complications, including pain and bleeding, was minimal after ESP, and a few patients reported an abnormal sensation around the soft palate and swallowing difficulty after ESP. CONCLUSIONS AND RELEVANCE: Expansion sphincter pharyngoplasty appears to be a promising surgical technique to reduce lateral pharyngeal collapse in patients with moderate or severe OSA. Clinical data suggest that both severe palatal circumferential narrowing and bulky lateral pharyngeal tissue are favorable surgical indications for ESP in patients with OSA.

Comparison Between Signature Cytokines of Nasal Tissues in Subtypes of Chronic Rhinosinusitis.

PURPOSE: Endotype in chronic rhinosinusitis (CRS) has been established in the last decade. However, the exact immunologic profile of CRS still has controversy because it has a considerable immunologic heterogeneity. Therefore, we investigated various inflammatory mediators according to different nasal tissues in chronic rhinosinusitis and compared them within the same subject. METHODS: We collected uncinate process mucosa (UP) and nasal polyp (NP) tissues from controls, CRS without NP (CRSsNP) and CRS with NP (CRSwNP). Expression levels of 28 inflammatory mediators including T helper (Th) 1, Th2, Th17, proinflammatory cytokines and remodeling markers were determined by multiplex immunoassay and were analyzed using paired tests as well as principal component analysis (PCA) to investigate endotype in each subtype of CRS. RESULTS: Signature inflammatory mediators are interleukin (IL)-5, C-C motif chemokine ligand (CCL)-24, monocyte chemoattractant protein (MCP)-4, and vascular cell adhesion molecule (VCAM)-1 in eosinophilic NP, whereas IL-17A, IL-1ß, and matrix metallopeptidase (MMP)-9 were detected as signature inflammatory markers in non-eosinophilic NP. Despite differences in inflammatory cytokine profile between eosinophilic and non-eosinophilic NP, the common upregulation of IL-5, CCL-11, IL-23, IL-2Rα, VCAM-1, MMP-3 and MMP-9 were shown in NP compared to UP within the same subject. In the PCA, we observed that Th2 immune response was helpful in discriminating between nasal tissues in subtypes of CRS and that there was a partial overlap between non-eosinophilic NP and eosinophilic NP in terms of Th2 mediators. CONCLUSIONS: Commonly upregulated mediators in NP were Th2-associated, compared with UP regardless of CRS subtypes, whereas signature markers were distinct in each NP subtype. These findings imply that Th2 inflammatory responses may play a role in the development of NP regardless of CRSwNP subtypes.

Effect of Ginkgo Biloba Extract on N-Methyl-D-Aspartic Acid Receptor Subunit 2B Expression in a Salicylate-Induced Ototoxicity Model.

OBJECTIVES: Sodium salicylate (SS) is well known for its ototoxic properties that induce functional and morphological changes in the cochlea and brain. Ginkgo biloba extract (GBE) has been widely used for treatment of various neurodegenerative diseases; however, its effects on salicylate-induced ototoxicity remain unclear. Herein, we examined the effects of EGb 761 (EGb), a standard form of GBE, on the plasticity of the N-methyl-D-aspartate receptor subunit 2B (GluN2B) in the inferior colliculus (IC) following SS administration. METHODS: Seven-week-old Sprague Dawley rats (n=24) were randomly allocated to control, SS, EGb, and EGb+SS groups. The SS group received a single intraperitoneal SS injection (350 mg/kg), the EGb group received EGb orally for 5 consecutive days (40 mg/kg), and the EGb+SS group received EGb for 5 consecutive days, followed by an SS injection. The auditory brainstem responses (ABRs) were assessed at baseline and 2 hours after SS administration. GluN2B expression was examined by Western blot and immunohistochemistry. RESULTS: There were no significant differences in ABR threshold shifts among the groups. The expression of the GluN2B protein normalized by which of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was significantly lower in the EGb+SS group, as compared to the SS group (P=0.012). Weak and diffused GluN2B immunoreactivity was detected in the IC neural cells of the EGb+SS group, while those of the SS group exhibited strong and diffused GluN2B positivity. CONCLUSION: EGb may play a role in regulating the GluN2B expression in the IC of salicylate-induced ototoxicity model.

Comparison of endoscopic and microscopic ear surgery in pediatric patients: A meta-analysis.

OBJECTIVES: Recently, the endoscope has been increasingly introduced for middle-ear surgery. To evaluate the postoperative outcomes of endoscopic ear surgery (EES) in pediatric patients, we did a qualitative analysis with a systematic review and quantitative analysis with meta-analysis of available literature. METHODS: Studies reporting the comparative surgical outcomes of EES in pediatric patients were systematically reviewed by searching the MEDLINE, PubMed, and Embase databases from database inception through 2017. The selected articles included clinical studies conducted with at least 30 subjects and at least one postoperative parameter, including residual or recurrent cholesteatoma and graft success in tympanoplasty. Two investigators independently reviewed all studies and extracted the data using a standardized form. A meta-analysis was performed using a random-effects model and qualitative review was performed on the smaller studies. RESULTS: Ten studies were identified as appropriate for quantitative meta-analysis and 19 studies for qualitative analysis. In the meta-analysis, residual or recurrence rate of cholesteatoma was significantly lower in the EES group than in the microscopic ear surgery (MES) group (odds ratio [OR]: 0.56, 95% confidence interval [CI]: 0.38-0.84, P = .005). The graft success rate of tympanoplasty was not statistically different between EES and MES groups (OR: 0.72, 95% CI: 0.41-1.26, P = .249). In the qualitative analysis, most of the studies reported similar audiological outcomes after tympanoplasty and success rate of cholesteatoma removal between the two groups. CONCLUSIONS: It appears that EES reduces the risk of residual cholesteatoma in children and that the success of perforation closure is equivalent to MES. Laryngoscope, 129:1444-1452, 2019.

Two-Track Medical Treatment Strategy According to the Clinical Scoring System for Chronic Rhinosinusitis.

PURPOSE: The previously reported Japanese clinical scoring study (JESREC) suggests that chronic rhinosinusitis (CRS) can be divided into 4 subtypes according to the degree of eosinophilic CRS (ECRS) and offers the information regarding the prognosis of CRS to clinicians. However, this scoring system has not yet been validated by an immunological study and needs to provide treatment guidelines based on underlying immunologic profiles. We investigated the immunologic profile of each CRS subgroup according to the JESREC classification and suggest its clinical application. METHODS: A total of 140 CRS patients and 20 control subjects were enrolled. All patients were classified into 4 groups according to the JESREC (non-, mild, moderate and severe ECRS). Nasal tissues were analyzed for mRNA expression of major cytokines (IL-5, IL-10, IL-13, IL-17A, IL-22, IL-23p19, IFN-γ, periostin, thymic stromal lymphopoietin [TSLP] and ST2), major chemokines (CCL11, CCL24, CXCL1 and CXCL2), transcription factors (T-bet, GATA3, RORC and FOXP3) and COL1A1 for type I collagen. Protein levels of 3 major cytokines (IL-5, IL-17A and IFN-γ) were also measured by multiplex immunoassay. Principal component analysis (PCA) was conducted to investigate the overall profile of multiple mediators. RESULTS: The moderate/severe ECRS showed up-regulation of type 2-related mediators (IL-5, IL-13, periostin, TSLP and ST-2), whereas INF-γ (type 1 cytokine) and CXCL1 (neutrophil chemokine) expressions were increased in non-/mild ECRS compared with moderate/severe ECRS. The JESREC classification reflected an immunological endotype. In PCA data, PCA1 indicates a relative type 2 profile, whereas PCA2 represents a type 1/type 17-related profile. In this analysis, mild ECRS was indistinguishable from non-ECRS, whereas moderate to severe ECRS showed a distinct distribution compared with non-ECRS. The JESREC classification could be divided into 2 categories, non-/mild vs. moderate/severe ECRS based on underlying immunological analyses. CONCLUSIONS: The CRS clinical scoring system from the JESREC study reflects an inflammatory endotype. However, the immunologic profile of mild ECRS was similar to that of non-ECRS. Therefore, we propose type 2-targeted medical treatment for moderate to severe ECRS and type 1/type 17-targeted for non-ECRS and mild ECRS as the first treatment option.

Stability of virus-like particles of red-spotted grouper nervous necrosis virus in the aqueous state, and the vaccine potential of lyophilized particles.

Virus-like particles (VLPs) are multi protein complexes mimicking the structural properties of the native virus. The development of freeze-dried formulations of such complex protein structures remains a challenge. Red-spotted grouper nervous necrosis virus (RGNNV) causes mass mortality in fish culture, and RGNNV VLPs have been suggested to be promising vaccine candidates. In the present study, the stability of RGNNV VLPs in the liquid state was investigated over a 4-week period, along with the influence of freeze-drying on VLP stability. RGNNV VLPs were completely degraded after one week at 37 °C followed by 3 weeks at ambient temperature, and they were partially degraded after 4 weeks at 4 °C. Therefore, the inherent stability of RGNNV VLP in an aqueous milieu is insufficient for long-term storage. When RGNNV VLPs were freeze-dried in the presence or absence of sugar stabilizers, sorbitol was found to improve VLP stability whereas mannitol reduced it. VLP preparations freeze-dried with sorbitol or without stabilizer were as immunogenic as control (non-freeze dried) VLPs, whereas VLPs freeze-dried in mannitol were less immunogenic. These results indicate that freeze-dried RGNNV VLPs have potential as vaccines.

Oral vaccination through voluntary consumption of the convict grouper Epinephelus septemfasciatus with yeast producing the capsid protein of red-spotted grouper nervous necrosis virus.

Nervous necrosis viruses (NNV) cause serious economic losses in marine fish cultivation. The red-spotted grouper NNV (RGNNV) is the most common species of NNV worldwide. There have been many efforts to develop prophylactic NNV vaccines, and various types of vaccine candidate have been suggested. However, most were designed as injectable vaccines, which are not suitable for large-scale vaccination and cause too much stress to the fish. Oral vaccination through voluntary feeding is an ideal way to provide protective immunity to fish. In the present study, recombinant Saccharomyces cerevisiae producing RGNNV capsid protein was used as oral vaccine. The recombinant yeast was prepared in freeze-dried form after disruption. Convict groupers were divided into three groups, control, and oral and parenteral vaccination groups, each consisting of 700 fishes. The control group received no treatment, the parenteral group received one intraperitoneal injection of RGNNV virus-like particles, and the oral vaccination group consumed feed containing the lysed recombinant yeast; voluntary intake was allowed four times at one-week intervals. Both vaccination groups produced serum RGNNV neutralizing antibody titers of >103 (log 2, 9.96), sustained for at least 95days post-immunization. In addition, in response to challenge with RGNNV both groups suffered significantly reduced mortality and had reduced brain RGNNV titers. These results indicate that recombinant yeast-based oral fish vaccines have great potential for large-scale vaccination.

Genetic Characteristics and Immunogenicity of Pandemic H1N1 Influenza Virus Isolate from Pig in Korea.

A pandemic influenza A (H1N1) virus strain was isolated from a pig farm in Korea in December 2009. The strain was propagated in and isolated from both the Madin-Darby canine kidney cell line and embryonated eggs. The partial and complete sequences of the strain were identical to those of A/California/04/2009, with >99% sequence similarity in the HA, NA, M, NS, NP, PA, PB1, and PB2 genes. The isolated strain was inactivated and used to prepare a swine influenza vaccine. This trial vaccine, containing the new isolate that has high sequence similarity with the pandemic influenza A (H1N1) virus, resulted in seroconversion in Guinea pigs and piglets. This strain could therefore be a potential vaccine candidate for swine influenza control in commercial farms.

Comparison of the antigenic relationship between Japanese encephalitis virus genotypes 1 and 3.

PURPOSE: The Japanese encephalitis virus (JEV) genotype circulating in Korea has changed from G3 to G1. Therefore, the purpose of this study was to compare the antigenic relationship between the two genotypes by using antibody tests. MATERIALS AND METHODS: Blood samples from 42 sows and 216 horses were collected, and their seroprevalence was monitored using the hemagglutination inhibition and virus neutralization tests. Antisera against JEV G1 and G3 were isolated and prepared from guinea pigs. The cross-reactivity of these two viruses was then compared using the neutralizing antibody test. RESULTS: We found that there was a difference in the seropositive ratios of JEV G1 and G3. However, the difference was dependent on the antibody test used. There was also an observed difference in the antigenicity between the two genotypes, as ascertained using the neutralizing antibody test. CONCLUSION: There is an evident difference in JEV antigenicity between the genotypes G1 and G3. Therefore, we propose monitoring of the seroprevalence of JEV, and reevaluating the antigenicity of the current vaccine by using the relevant tests.

Factors associated with polyp regression after intravitreal ranibizumab injections for polypoidal choroidal vasculopathy.

PURPOSE: To investigate the predictive factors of polyp regression after intravitreal ranibizumab injections for polypoidal choroidal vasculopathy (PCV). METHODS: Sixty-nine eyes (69 patients) with treatment-naïve PCV received an initial series of 3-monthly intravitreal ranibizumab injections, followed by as-needed injections. Polyp regression was determined after 6 months from baseline by means of indocyanine angiography and correlated with clinical characteristics at baseline. RESULTS: After treatment, 26.1% (18 out of 69 eyes) achieved complete polyp regression and 73.9% (51 out of 69 eyes) showed persistent polyps. The mean logarithm of the minimum angle of resolution (logMAR) of best-corrected visual acuity (BCVA) was significantly improved in both groups (P = 0.02). No statistically significant difference in BCVA improvement was observed between the groups. However, the proportion of subjects with BCVA improvement by more than three lines was significantly higher in the polyp regression group (P = 0.02). Univariate analysis of the baseline characteristics identified the number of polyps (P = 0.02), the total polyp area (P = 0.009) and the polyp pattern (P = 0.01) as predictive factors for polyp regression. Multivariate logistic regression identified the total polyp area (P = 0.01) as an independent predictor for polyp regression after intravitreal ranibizumab injections. CONCLUSIONS: The regression of polypoidal lesions in PCV patients after intravitreal ranibizumab injections was associated with a smaller total polyp area. This result could be helpful in predicting polypoidal changes after ranibizumab treatment and in deciding the best treatment strategy for PCV patients.

Expression and characterization of cathepsin L-like cysteine protease from Philasterides dicentrarchi.

Philasterides dicentrarchi is a causative agent of scuticociliatosis in olive flounder Paralichthys olivaceus, aquaculture in Korea. In this study, a cDNA encoding a cathepsin L-like cysteine protease (PdCtL) of P. dicentrarchi (synonym Miamiensis avidus) was identified. To express the PdCtL recombinant protein in a heterologous system, 10 codons were redesigned to conform to the standard eukaryotic genetic code using polymerase chain reaction (PCR)-based site-directed mutagenesis. The recombinant P. dicentrarchi procathepsin L (proPdCtL) was expressed at high levels in E. coli Rosetta (DE3) pLysS with a pPET21a vector, and successfully refolded, purified, and activated into a functional and enzymatically active form. The optimal pH for protease activity was 5. Similar to other cysteine proteases, enzyme activity was inhibited by E64 and leupeptin. Immunogenicity of recombinant PdCtL was assessed by enzyme-linked immunosorbent assay, western blot, and specific anti-recombinant PdCtL antibodies were detected. Our results suggest that the biochemical characteristics of the recombinant ciliate proPdCtL protein are similar to those of the cathepsin L-like cysteine protease, that the PCR-based site-direct mutated ciliate gene was successfully expressed in a biochemically active form, and that the recombinant PdCtL acted as a specific epitope in olive flounder.

Isolation, molecular characterization, and antibiotic susceptibility of Vibrio parahaemolyticus in Korean seafood.

The principal objective of this study was to investigate the incidence, risk assessment, antibiotic resistance, and genotyping of Vibrio parahaemolyticus in Korean seafood. The incidence of V. parahaemolyticus in seafood obtained from several fish markets in Korea was investigated from May to December of 2009, except between July and September. Two selective mediums (TCBS [thiosulfate, citrate, bile salts, and sucrose] agar and CHROMagar™ Vibrio) were used, and the V. parahaemolyticus strains were identified via polymerase chain reaction (PCR) amplification (Vp. flaE, tl, and toxR). 16S rRNA gene sequencing and their virulence were analyzed via the detection of tdh, trh, ORF8, toxRS/old, and toxRS/new genes. We collected 24 strains of V. parahaemolyticus: 19 seafood isolates, three environmental isolates, and two clinical (human) isolates. Among these strains, two tdh+ strains, two ORF8+ strains, 16 toxRS/old+ strains, and one toxRS/new+ strain were isolated. Twenty-two commercial antibiotics were used to assess the antibiotic susceptibility of isolates, and all the strains evidenced resistance to more than four antibiotics. The strains harboring antibiotic-resistant genes such as TetA (25%) and strB (4.16%) were detected via PCR. Repetitive extragenic palindromic sequence (REP)-PCR analysis revealed differences in the V. parahaemolyticus strains from other species and intraspecific strains.

First description of the qnrS-like (qnrS5) gene and analysis of quinolone resistance-determining regions in motile Aeromonas spp. from diseased fish and water.

Antimicrobial resistance patterns in a collection of 33 motile Aeromonas species were described in this study. Quinolone has been frequently employed for treatment of Aeromonas-related diseases, and prolonged use of antimicrobial compounds has led to development of resistant strains. In a sample of diseased fish and environmental water, we evaluated nalidixic acid (n = 19) and ciprofloxacin (n = 4) resistance via minimum inhibitory concentration (MIC) assays and the genetic basis was also investigated. Among the isolated Aeromonas spp., 17 strains encoded for chromosomal mutations of quinolone resistance-determining regions (QRDRs) in gyrA, 11 strains encoded for mutations of QRDRs in parC, 1 strain harbored plasmid-mediated quinolone resistance (PMQR) qnrS1-like gene and 4 strains harbored the PMQR qnrS2 gene. In particular, the new variant (qnrS1-like) differed from qnrS1 by 6 amino acid substitutions at positions 5 (Asn(5)→Arg(5)), 120 (Ser(120)→Thr(120)), 148 (Asn(148)→His(148)), 206 (Leu(206)→Glu(206)), 207 (Ile(207)→ Leu(207)), and 216 (Tyr(216)→Phe(216)), and the gene was designated qnrS5. These resistant strains may function as reservoirs of quinolone resistance.

Expression of Transforming Growth Factor-beta and Its Receptors during Acetic Acid-induced Duodenal Ulcer Healing in Rats

BACKGROUND: Many works have been written about the transforming growth factor-beta 1 (TGF-beta1) which is closely associated with fibrosis in the inflammatory conditions of different organs. TGF-beta1 exerts its biological effects by interacting with specific cell surface receptors, namely, transforming growth factor-beta receptor type I and II (TGFbetaRI and TGFbetaRII). METHODS:To investigate the temporal expressions and localizations of TGF-beta1, TGFRbetaI, and TGFbetaRII in acetic acid-induced duodenal ulcerated tissues, we performed in situ hybridization and immunohistochemical techniques. RESULTS: Under in situ hybridization, TGF-beta1, TGFbetaRI, and TGFbetaRII mRNA signals increased in the experimental groups (1, 3, 7, and 14 day groups) compared to those of the control group. The signals on day 14 decreased slightly compared to those of days 1, 3, and 7, but they were higher than those of the control group. Under immunohistochemical study, TGF-beta1, TGFbetaRI, and TGFbetaRII were localized in the mucosal epithelial cells and in the macrophages, vascular endothelial cells, and fibroblasts of the lamina propria and granulation tissue. As in the case of the in situ hybridization, it revealed that the expression of three proteins increased in the experimental groups compared to that of the control group. The expression on day 14 decreased compared to those of days 1, 3, and 7, but it was more intense than that of the control group. CONCLUSIONS: This study suggests that TGF-beta1, TGFbetaRI, and TGFbetaRII contribute to the early stage healing of duodenal ulcer.