Swd2/Cps35 determines H3K4 tri-methylation via interactions with Set1 and Rad6.

BACKGROUND: Histone H3K4 tri-methylation (H3K4me3) catalyzed by Set1/COMPASS, is a prominent epigenetic mark found in promoter-proximal regions of actively transcribed genes. H3K4me3 relies on prior monoubiquitination at the histone H2B (H2Bub) by Rad6 and Bre1. Swd2/Cps35, a Set1/COMPASS component, has been proposed as a key player in facilitating H2Bub-dependent H3K4me3. However, a more comprehensive investigation regarding the relationship among Rad6, Swd2, and Set1 is required to further understand the mechanisms and functions of the H3K4 methylation. RESULTS: We investigated the genome-wide occupancy patterns of Rad6, Swd2, and Set1 under various genetic conditions, aiming to clarify the roles of Set1 and Rad6 for occupancy of Swd2. Swd2 peaks appear on both the 5' region and 3' region of genes, which are overlapped with its tightly bound two complexes, Set1 and cleavage and polyadenylation factor (CPF), respectively. In the absence of Rad6/H2Bub, Set1 predominantly localized to the 5' region of genes, while Swd2 lost all the chromatin binding. However, in the absence of Set1, Swd2 occupancy near the 5' region was impaired and rather increased in the 3' region. CONCLUSIONS: This study highlights that the catalytic activity of Rad6 is essential for all the ways of Swd2's binding to the transcribed genes and Set1 redistributes the Swd2 to the 5' region for accomplishments of H3K4me3 in the genome-wide level.

Role of the Paf1 complex in the maintenance of stem cell pluripotency and development.

Cell identity is determined by the transcriptional regulation of a cell-type-specific gene group. The Paf1 complex (Paf1C), an RNA polymerase II-associating factor, is an important transcriptional regulator that not only participates in transcription elongation and termination but also affects transcription-coupled histone modifications and chromatin organisation. Recent studies have shown that Paf1C is involved in the expression of genes required for self-renewal and pluripotency in stem cells and tumorigenesis. In this review, we focused on the role of Paf1C as a critical transcriptional regulator in cell fate decisions. Paf1C affects the pluripotency of stem cells by regulating the expression of core transcription factors such as Oct4 and Nanog. In addition, Paf1C directly binds to the promoters or distant elements of target genes, thereby maintaining the pluripotency in embryonic stem cells derived from an early stage of the mammalian embryo. Paf1C is upregulated in cancer stem cells, as compared with that in cancer cells, suggesting that Paf1C may be a target for cancer therapy. Interestingly, Paf1C is involved in multiple developmental stages in Drosophila, zebrafish, mice and even humans, thereby displaying a trend for the correlation between Paf1C and cell fate. Thus, we propose that Paf1C is a critical contributor to cell differentiation, cell specification and its characteristics and could be employed as a therapeutic target in developmental diseases.

Broad domains of histone H3 lysine 4 trimethylation in transcriptional regulation and disease.

Histone modifications affect transcription by changing the chromatin structure. In particular, histone H3 lysine 4 trimethylation (H3K4me3) is one of the most recognized epigenetic marks of active transcription. While many studies have provided evidence of the correlation between H3K4me3 and active transcription, details regarding the mechanism involved remain unclear. The first study on the broad H3K4me3 domain was reported in 2014; subsequently, the function of this domain has been studied in various cell types. In this review, we summarized the recent studies on the role of the broad H3K4me3 domain in transcription, development, memory formation, and several diseases, including cancer and autoimmune diseases. The broadest H3K4me3 domains are associated with increased transcriptional precision of cell-type-specific genes related to cell identity and other essential functions. The broad H3K4me3 domain regulates maternal zygotic activation in early mammalian development. In systemic autoimmune diseases, high expression of immune-responsive genes requires the presence of the broad H3K4me3 domain in the promoter-proximal regions. Transcriptional repression of tumor-suppressor genes is associated with the shortening of the broad H3K4me3 domains in cancer cells. Additionally, the broad H3K4me3 domain interacts with the super-enhancer to regulate cancer-associated genes. During memory formation, H3K4me3 breadth is regulated in the hippocampus CA1 neurons. Taken together, these findings indicate that H3K4me3 breadth is essential for the regulation of the transcriptional output across multiple cell types.

Complete genome sequence and comparative analysis of Streptomyces seoulensis, a pioneer strain of nickel superoxide dismutase.

BACKGROUND: Streptomyces seoulensis has contributed to the discovery and initiation of extensive research into nickel superoxide dismutase (NiSOD), a unique type of superoxide dismutase found in actinomycetes. Still so far, there is no information about whole genome sequence of this strain. OBJECTIVE: To investigate complete genome sequence and perform bioinformatic analyses for genomic functions related with nickel-associated genes. METHODS: DNA was extracted using the Wizard Genomic DNA Purification Kit then sequenced using a Pacific Biosciences SMRT cell 8Pac V3 DNA Polymerase Binding Kit P6 with the PacBiov2 RSII platform. We assembled the PacBio long-reads with the HGAP3 pipeline. RESULTS: We obtained complete genome sequence of S. seoulensis, which comprises a 6,339,363 bp linear chromosome. While analyzing the genome to annotate the genomic function, we discovered the nickel-associated genes. We observed that the sodN gene encoding for NiSOD is located adjacent to the sodX gene, which encodes for the nickel-type superoxide dismutase maturation protease. In addition, several nickel-associated genes and gene clusters-nickel-responsive regulator, nickel uptake transporter, nickel-iron [NiFe]-hydrogenase and other putative genes were also detected. Strain specific genes were discovered through a comparative analysis of S. coelicolor and S. griseus. Further bioinformatic analyses revealed that this strain encodes at least 22 putative biosynthetic gene clusters, thereby implying that S. seoulensis has the potential to produce novel bioactive compounds. CONCLUSION: We annotated the genome and determined nickel-associated genes and gene clusters and discovered biosynthetic gene clusters for secondary metabolites implying that S. seoulensis produces novel types of bioactive compounds.

Elongation factor P controls translation of the mgtA gene encoding a Mg2+ transporter during Salmonella infection.

Ribosome often stalls on mRNA sequences harboring consecutive proline codons. Elongation factor P (EF-P) is required for the stalled ribosome to continue translation and thus the absence of EF-P affects translation of the associated open reading frame. Here we report that EF-P controls translation of the mgtA gene encoding a Mg2+ -transporting ATPase from the intracellualr pathogen Salmonella enterica serovar Typhimurium. EF-P's effect on mgtA translation is dependent on the 550th and 551st proline codons in the coding region and thus substitution of those proline codons eliminates EF-P-mediated control of MgtA protein without affecting the Mg2+ -transporting activity of the mgtA gene. The Pro550 and Pro551-substituted mgtA gene promotes Salmonella's intramacrophage survival and mouse virulence, suggesting that EF-P-mediated translational control of the mgtA gene is required for Salmonella pathogenesis.

Epigenetic Control of Oxidative Stresses by Histone Acetyltransferases in Candida albicans.

Candida albicans is a major pathogenic fungus in humans, and meets at first the innate immune cells, such as macrophages, in its host. One important strategy of the host cell to kill C. albicans is to produce reactive oxygen species (ROS) by the macrophages. In response to ROS produced by the macrophages, C. albicans operates its defense mechanisms against them by expressing its oxidative stress response genes. Although there have been many research studies explaining the specific transcription factors and the expression of the oxidative stress genes in C. albicans, the regulation of the oxidative stress genes by chromatin structure is little known. Epigenetic regulation by the chromatin structure is very important for the regulation of eukaryotic gene expression, including the chromatin structure dynamics by histone modifications. Among various histone modifications, histone acetylation is reported for its direct relationship to the regulation of gene expression. Recent studies reported that histone acetyltransferases regulate genes to respond to the oxidative stress in C. albicans. In this review, we introduce all histone acetyltransferases that C. albicans contains and some papers that explain how histone acetyltransferases participate in the oxidative stress response in C. albicans.

Targeting Apolipoprotein E/Amyloid ß Binding by Peptoid CPO_Aß17-21 P Ameliorates Alzheimer's Disease Related Pathology and Cognitive Decline.

Inheritance of the apolipoprotein E4 (apoE4) genotype has been identified as the major genetic risk factor for late onset Alzheimer's disease (AD). Studies have shown that apoE, apoE4 in particular, binds to amyloid-ß (Aß) peptides at residues 12-28 of Aß and this binding modulates Aß accumulation and disease progression. We have previously shown in several AD transgenic mice lines that blocking the apoE/Aß interaction with Aß12-28 P reduced Aß and tau-related pathology, leading to cognitive improvements in treated AD mice. Recently, we have designed a small peptoid library derived from the Aß12-28 P sequence to screen for new apoE/Aß binding inhibitors with higher efficacy and safety. Peptoids are better drug candidates than peptides due to their inherently more favorable pharmacokinetic properties. One of the lead peptoid compounds, CPO_Aß17-21 P, diminished the apoE/Aß interaction and attenuated the apoE4 pro-fibrillogenic effects on Aß aggregation in vitro as well as apoE4 potentiation of Aß cytotoxicity. CPO_Aß17-21 P reduced Aß-related pathology coupled with cognitive improvements in an AD APP/PS1 transgenic mouse model. Our study suggests the non-toxic, non-fibrillogenic peptoid CPO_Aß17-21 P has significant promise as a new AD therapeutic agent which targets the Aß related apoE pathway, with improved efficacy and pharmacokinetic properties.

Elongation factor P restricts Salmonella's growth by controlling translation of a Mg2+ transporter gene during infection.

When a ribosome translates mRNA sequences, the ribosome often stalls at certain codons because it is hard to translate. Consecutive proline codons are such examples that induce ribosome stalling and elongation factor P (EF-P) is required for the stalled ribosome to continue translation at those consecutive proline codons. We found that EF-P is required for translation of the mgtB gene encoding a Mg2+ transporter in the mgtCBR virulence operon from the intracellular pathogen Salmonella enterica serovar Typhimurium. Salmonella lacking EF-P decreases MgtB protein levels in a manner dependent on consecutive proline codons located in the mgtB coding region despite increasing transcription of the mgtCBR operon via the mgtP open reading frame in the leader RNA, resulting in an altered ratio between MgtC and MgtB proteins within the operon. Substitution of the consecutive proline codons to alanine codons eliminates EF-P-mediated control of the mgtB gene during infection and thus contributes to Salmonella's survival inside macrophages where Salmonella experiences low levels of EF-P. This suggests that this pathogen utilizes a strategy to coordinate expression of virulence genes by an evolutionarily conserved translation factor.

Development of a drug delivery system for the inner ear using poly(amino acid)-based nanoparticles.

CONTEXT: Local delivery systems for treatment of intractable inner ear disorders have been attempted by many investigators. OBJECTIVE: To evaluate the permeability and safety of a drug delivery system for the inner ear using a poly(2-hydroxyethyl aspartamide) (PHEA) polymersome. MATERIALS AND METHODS: One-month-old male C57/BL6 mice were used. We administered the same amount of the fluorescent dye, Nile red, into the middle ear in two forms: loaded in PHEA polymersomes (NP group) or diluted in ethanol (NR group). At 1 day after administration, we harvested the cochlea and counted visible red particles in the tissues of cochlea under confocal microscopy and compared the groups. In a safety evaluation, 1 week after the same surgery, we conducted hearing tests and histological evaluations of the bulla and cochlea, and compared the results with those of the sham operation and negative control groups. RESULTS: In terms of permeability, the number of red particles in the organ of Corti was increased significantly in the NP group, and three subjects in the NP group showed uptake of red particles in inner hair cells. However, there was no statistically significant difference in the observations in the lateral wall or modiolus. In safety tests, the NP and sham-operation groups showed decreased DPOAE responses and mildly swollen middle ear mucosa, compared with the negative control group, which was thought to be the result of postoperative changes. CONCLUSIONS: PHEA nanoparticles may have utility as a drug carrier into the inner ear in terms of both permeability and safety.

Predictors for outcome of paper patch myringoplasty in patients with chronic tympanic membrane perforations.

The purpose of the present study is to evaluate the outcome of paper patch myringoplasty for chronic tympanic membrane (TM) perforations and to explore the predictive factors for a successful closure. A retrospective study was performed in a tertiary referral center. Data of the patients who met the inclusion criteria were analyzed: the treatment outcomes and the potential predictive factors including age, sex, the affected ear, hearing level, duration of perforation, causes, location and size of perforations, relationship between the perforation border and the malleus, status of TM surface, and the number of patch applications. Complete closure was achieved in 27 of the total 43 subjects. Among the 11 clinical and TM factors, only the perforation size remained significant as the predictor after multivariable logistic regression (p = 0.029, OR 4.4). The patients with perforation ≤ 5% of the TM showed higher closure rate (78.3%) than those with perforation >5% (45.0%). In conclusion, paper patch myringoplasty showed overall success rate of 62.8%. In patients with perforations smaller than 5% of the TM, the closure rate was 78.3%. The predictor of the treatment outcome was the perforation size. We can try paper patch myringoplasty first in patients who had dry chronic perforations smaller than 5% of the TM without middle ear disease.

A case of direct intracranial extension of tuberculous otitis media.

We describe a very rare case of tuberculous otitis media (TOM) with direct intracranial extension. The patient was a 55-year-old man who presented to our ENT clinic for evaluation of severe headaches and right-sided otorrhea. A biopsy of granulation tissue obtained from the right external auditory canal demonstrated chronic inflammation that was suggestive of mycobacterial infection. Magnetic resonance imaging of the brain indicated intracranial extension of TOM through a destroyed tegmen mastoideum. After 2 months of antituberculous medication, the headaches and otorrhea were controlled, and the swelling in the external ear canal subsided greatly. Rarely does TOM spread intracranially. In most such cases, intracranial extension of tuberculosis occurs as the result of hematogenous or lymphogenous spread. In rare cases, direct spread through destroyed bone can occur, as it did in our patient.

Diagnostic value and clinical significance of stress hormones in patients with tinnitus.

Tinnitus has been found to be modulated by stress and is also closely related to the emotional state and the limbic system. In the present study, we evaluated the diagnostic and clinical values of several stress hormones in a large number of tinnitus patients. This study included 344 patients with sensorineural tinnitus and 87 normal controls. A questionnaire about tinnitus was administered to the participants, and blood levels of norepinephrine (NE), epinephrine (Epi), a metabolite of serotonin (5-hydroxyindoleacetic acid, 5-HIAA) and cortisol were compared between groups. In results, the mean values of Beck's depression inventory (BDI), Brief Encounter Psychosocial Instrument (BEPSI), NE, and 5-HIAA levels were higher in the tinnitus group, although there was no statistical significance. But, the proportion of participants with elevated 5-HIAA was significantly higher in the tinnitus group (21.8 vs. 8.0 %, P < 0.05), and the 5-HIAA level significantly correlated with the duration of tinnitus, NE and cortisol. Elevated stress-related hormones, as well as hearing loss, BDI, and BEPSI were the most related factors with tinnitus in multiple regression test with age adjustment. However, levels of stress-related hormones did not correlate with subjective measures including BDI, BEPSI and severity of tinnitus. In conclusion, blood stress hormones seemed to have some diagnostic and clinical value in patients with tinnitus, and serotonin is supposed to be the most important hormone in tinnitus. Further studies about the values of stress and stress hormones in tinnitus patients may lead to new approaches regarding diagnosis and clinical management of the disease.

Childhood tinnitus: clinical characteristics and treatment.

PURPOSE: Troublesome tinnitus in children can have an impact on their lives leading to behavioral or psychological problems. The present study was designed to identify the clinical features of childhood tinnitus, to establish the treatment strategy for each tinnitus category and severity, and to assess the treatment outcomes. MATERIALS AND METHODS: Clinical data were retrospectively collected on 108 tinnitus patients in childhood and adolescence. The authors have classified tinnitus according to the acoustic source: otic (idiopathic subjective), myoclonic, and vascular tinnitus based on the tinnitus quality and appropriate diagnostic approaches. Treatment selection depended on the tinnitus category and severity. Treatment modalities included counseling, a simplified tinnitus retraining therapy, counseling with medications, and surgery. RESULTS: Of all 108 subjects, otic tinnitus was the most common form of childhood tinnitus (n=80) followed by myoclonic (n=21) and vascular tinnitus (n=6). The prevalence of otic tinnitus increased with age. The mean age of myoclonic tinnitus patients was younger than that of the others. The majority of otic tinnitus showed normal hearing. The origin of 81% of myoclonic tinnitus was middle ear muscles. Of all subjects, 67.6% had mild tinnitus responsive to counseling alone. Distressing tinnitus was most common in myoclonic tinnitus. Almost all patients (97%) who were followed up at 3 months (64%) showed improvements. CONCLUSIONS: We suggest that understanding the clinical characteristics of childhood tinnitus, establishing a diagnosis based on the acoustic source, and implementing appropriate therapy customized to the individual tinnitus category and severity would help clinicians to relieve tinnitus children of their troublesome tinnitus effectively.

Tinnitus in patients with profound hearing loss and the effect of cochlear implantation.

The objectives of this study were to characterize the features of tinnitus in patients with profound sensorineural hearing loss and to evaluate the effect of cochlear implantation (CI) on their tinnitus. Medical records were reviewed for 35 patients who underwent CI, and completed tinnitus questionnaire between March 2003 and August 2011. Of them, 22 had tinnitus prior to CI (62.9 %) and the tinnitus group was older than the non-tinnitus group (47.5 ± 15.1 vs. 28.9 ± 15.2). The mean tinnitus handicap inventory (THI) score of the tinnitus group was 50.5 ± 28.7 before surgery, and the mean THI score and visual analogue scale (VAS) scores for loudness, annoyance, effect on life, and awareness decreased significantly after CI, with a mean follow-up period of 10.7 months. Tinnitus was completely eliminated in ten patients (45.5 %) and THI scores decreased in all patients. In a correlation analysis of the decrease in THI scores, preoperative VAS scores for loudness, awareness, effect on life, and annoyance, as well as preoperative THI scores, were highly correlated with the degree of decrease in THI scores postoperatively. The auditory performance of patients older than 40 years did not differ from that of younger patients, but their tinnitus was more improved after CI. In conclusion, tinnitus is a common complaint in patients with cochlear implants, and is more prevalent in elderly implantees. In the present study, CI improved tinnitus in all patients, although the most severe cases had the greatest benefit.

Effects of a tumor necrosis factor-α antagonist on experimentally induced rhinosinusitis.

This prospective, randomized, and controlled study examined the effects of tumor necrosis factor soluble receptor type I (sTNFRI, a TNF-α antagonist) on experimentally induced rhinosinusitis in rats. The experimental groups received an instillation of lipopolysaccharide (LPS) plus an intramuscular injection of amoxicillin/clavulanate (antibiotic group), an instillation of sTNFRI (sTNFRI group), an instillation of sTNFRI and an injection of amoxicillin/clavulanate (sTNFRI/antibiotic group), or no additional treatment (LPS group). Histopathological changes were determined using hematoxylin-eosin and periodic acid-Schiff (PAS) staining. Leakage of exudate was determined using fluorescence microscopy. Vascular permeability was measured using the Evans blue dye technique. Expression of MUC5AC was measured using reverse transcriptase PCR. The sTNFRI, antibiotic, and sTNFRI/antibiotic groups had significantly less capillary permeability, mucosal edema, PAS staining, and expression of MUC5AC than the LPS group. There were no differences in capillary permeability, mucosal edema, PAS staining, and MUC5AC expression between the sTNFRI and sTNFRI/antibiotic groups. The antibiotic group had PAS staining similar to that of the sTNFRI and sTNFRI/antibiotic groups but had a greater increase in capillary permeability, mucosal edema, and MUC5AC expression. This study shows that sTNFRI reduces inflammatory activity and mucus hypersecretion in LPS-induced rhinosinusitis in rats.

Tinnitus in patients with chronic otitis media before and after middle ear surgery.

The objective of this study was to investigate the clinical features of tinnitus in patients with chronic otitis media (COM) and to evaluate changes in tinnitus following middle ear surgery in relation to audiologic outcome. Medical records were reviewed for 117 patients with COM who underwent middle ear surgery between March 2009 and March 2010. Of them, 44 patients who pre-operatively reported tinnitus on a tinnitus questionnaire and 28 patients who completed a tinnitus questionnaire 8 weeks after surgery were evaluated to determine the clinical characteristics of tinnitus in patients with COM and any change in tinnitus following middle ear surgery, respectively. New tinnitus symptoms that developed after surgery were also evaluated in previously asymptomatic patients. The pre-operative incidence of tinnitus in patients with COM was 43% (50/117), with 87% of these patients displaying sensorineural tinnitus. After middle ear surgery, tinnitus handicap inventory scores were reduced in 82% of patients (23/28). Mean values of loudness, annoyance, effect on life, and awareness of tinnitus were also significantly reduced. One patient displayed newly developed tinnitus after surgery. Analysis of the relationship between improvement in tinnitus and audiologic outcome demonstrated that the group of patients whose tinnitus handicap inventory was reduced by more than 10 showed significantly greater improvements in mean air-conduction thresholds than did patients in the other group. In conclusion, following middle ear surgery, most patients experienced a reduction in tinnitus and restored hearing, with surgery perceived as an important contributory factor.

Expression of HSP70 and Its Relation with Other Cytokines in Human Middle Ear Effusion.

OBJECTIVES: While other cytokines are known to be associated with otitis media with effusion (OME), the involvement of heat shock protein 70 (HSP70) in middle ear effusion (MEE) is unknown. This study was undertaken to investigate the possibility of there being a HSP70 expression in human MEE and to determine its potential role as a cytokine in OME. METHODS: The levels of HSP70, tumor necrosis factor-alpha and interleukin-1beta were measured by enzyme-linked immunosorbent assay in the effusion of different groups of OME patient following collection of the MEE using our new collection system. The clinical characteristics of the OME patients and the MEE status were analyzed. RESULTS: HSP70 was expressed in all the types of MEE. The mucous and seromucous effusions showed higher HSP70 levels than that of the serous effusion. The HSP70 level was correlated with the levels of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta in the effusions. The positive correlations between HSP70, TNF-alpha and IL-1beta were statistically significant (P<0.05). CONCLUSION: The highly elevated level of HSP70 in the seromucous and mucous effusions implicates this protein in the chronicity of OME.

Insulin resistance and inflammation may have an additional role in the link between cystatin C and cardiovascular disease in type 2 diabetes mellitus patients.

Recent studies suggest that serum cystatin C level is not only a sensitive marker for renal dysfunction but also a predictive marker for cardiovascular disease (CVD). However, the mechanism of this connection is not fully understood. We aimed to determine whether insulin resistance or various biomarkers of cardiovascular risk have a role in the link between cystatin C and CVD in type 2 diabetes mellitus patients. Anthropometric measurements and biochemical studies including inflammatory biomarkers were performed in 478 patients with type 2 diabetes mellitus. The degree of insulin resistance was assessed by homeostasis model assessment (HOMA-IR) and indicators of metabolic syndrome. Estimated glomerular filtration rate (eGFR) was derived from the Modification of Diet in Renal Disease study equation. After adjusting for age, sex, body mass index, and eGFR, the cystatin C level increased significantly in proportion to the number of metabolic syndrome components present (1.08 +/- 0.06, 1.19 +/- 0.04, 1.20 +/- 0.04, 1.23 +/- 0.04, and 1.37 +/- 0.06 mg/L; P < .0001); and HOMA-IR increased significantly in proportion to cystatin C quartiles (1.16 +/- 0.15, 1.40 +/- 0.13, 1.49 +/- 0.13, and 2.00 +/- 0.17; P < .0001) (means +/- SE). Albumin-creatinine ratio, fibrinogen, uric acid, homocysteine, high-sensitivity C-reactive protein, and lipoprotein(a) all showed significant correlations with cystatin C that were generally higher than those with eGFR. Cystatin C level was independently associated with HOMA-IR (beta = 0.0380, P = .0082), albumin-creatinine ratio (beta = 0.0004, P < .0001), uric acid (beta = 0.0666, P < .0001), and homocysteine (beta = 0.0087, P = .0004). In conclusion, cystatin C level was significantly associated with insulin resistance and biomarkers reflecting inflammation independent of renal function. These components may have a role in addition to that of eGFR in explaining the link between cystatin C and CVD in type 2 diabetes mellitus patients.

Evaluation of the mydriatic effect of intracameral lidocaine hydrochloride injection in eyes of clinically normal dogs.

OBJECTIVE-To evaluate the mydriatic effect of intracameral injection of preservative-free 1% and 2% lidocaine hydrochloride solutions and determine the onset and duration of mydriasis according to the concentration and volume of lidocaine administered in healthy dogs. ANIMALS-5 healthy adult Beagles weighing 7 to 10 kg, with no apparent ocular disease. PROCEDURES-A double-blind randomized 9-session crossover trial was designed. Both eyes were assigned to 9 treatments with a minimum 7-day washout period between treatments: 0.1, 0.2, and 0.3 mL of 2% lidocaine solution; 0.1, 0.2, and 0.3 mL of 1% lidocaine solution; and 0.1, 0.2, and 0.3 mL of balanced salt solution. Dogs were anesthetized, and the allocated treatment was injected intracamerally after aspiration of the same volume of aqueous humor from the anterior chamber of each eye. Two perpendicular pupil diameters were measured. Intraocular pressure, heart rate, respiratory rate, ECG readings, and end-tidal partial pressure of CO(2) were monitored. RESULTS-Intracameral injection of 1% or 2% lidocaine solutions in volumes of 0.1 to 0.3 mL induced a significant degree of mydriasis, and the effect was maintained for 74 to 142 minutes. Lidocaine injection had no significant effect on intraocular pressure, heart rate, respiratory rate, ECG readings, or end-tidal partial pressure of CO(2). CONCLUSIONS AND CLINICAL RELEVANCE-Intracameral lidocaine injection in healthy dogs induced mydriasis, the timing of which was affected by concentration and volume of lidocaine. This technique could serve as an alternative to topically administered mydriatics for intraocular surgery in dogs.

Congenital middle ear cholesteatoma in children; retrospective review of 35 cases.

Congenital middle ear cholesteatoma (CMEC) is a rare disease entity in otolaryngology. However, we try to assess the characteristic features and recurrences of CMEC in pediatric patients according to stages, and to determine the value of preoperative computed tomography (CT) scan. Retrospective review of 35 cases of CMEC under the age of 15 yr that had been treated at the tertiary referral center from 1995 through 2006. The main outcome measures were CT findings, surgical findings, recurrence rate and hearing assessment. Preoperative CT scan accurately predicted the extent of the cholesteatoma seen during surgery in 30/35 (85.7%). The recurrence rate of CMEC was 5.7% (2/35) and all of recurred cases were stage IV. In recurred cases, cholesteatomas were extended to sinus tympani and facial recess at revisional operation as well as initial operation. So we concluded that preoperative CT scan is essential in defining the extent of existing pathology. The intraoperative CMEC extension and location influence the outcome of surgery. In the higher stages, careful eradication of disease, particularly in the region of sinus tympani and facial recess is recommended.