Hak Hyun Jung

Quantification of myosin heavy chain mRNA in somatic and branchial arch muscles using competitive PCR

The purpose of this study was to quantify the type and amount of myosin heavy chain (MHC) mRNA within muscles of different developmental origins to determine whether the regulation of gene expression is comparable. Seven MHC isoforms were analyzed in rat adult limb (extensor digitorum longus, tibialis anterior, and soleus) and nonlimb (extraocular, thyroarytenoid, diaphragm, and masseter) muscles using a competitive PCR assay. An exogenous template that included oligonucleotide sequences specific for seven rat sarcomeric MHC isoforms (beta-cardiac, 2A, 2X, 2B, extraocular, embryonic, and neonatal) as well as beta-actin was constructed and used as the competitor. Only the extraocular muscle contained all seven isoforms. All seven muscles contained type 2A and type 2X MHC transcripts in varying percentages. As expected, the soleus muscle contained primarily beta-cardiac MHC (87.8 +/- 2.6%). Extraocular MHC was found only in the extraocular and thyroarytenoid muscles and in relatively small proportions (7.4 +/- 1.5% and 4.0 +/- 0.7%, respectively). Neonatal MHC was identified in extraocular (7.9 +/- 0. 3%), thyroarytenoid (4.4 +/- 0.4%), and masseter (1.0 +/- 0.2%) muscles, and embryonic MHC was identified both in extraocular (1.2 +/- 0.5%) and, unexpectedly, in soleus (0.6 +/- 0.1%) muscles. Absolute MHC mRNA mass was greatest in the masseter (106 pg/0.5 microg RNA) and least for the tibialis anterior (64 pg/0.5 microg RNA). These values suggest that MHC mRNA represents from 4 to 17% of the total mRNA pool in various skeletal muscles. Differences in MHC profile between somatic and branchial arch muscles suggest that the developmental origin of a muscle may, at least in part, be responsible for the MHC expression program that is implemented in the adult. An inverse relationship between the expression of beta-cardiac and type 2B MHC transcripts across muscles was noted, suggesting that the expression of these two isoforms may be reciprocally regulated.The purpose of this study was to quantify the type and amount of myosin heavy chain (MHC) mRNA within muscles of different developmental origins to determine whether the regulation of gene expression is comparable. Seven MHC isoforms were analyzed in rat adult limb (extensor digitorum longus, tibialis anterior, and soleus) and nonlimb (extraocular, thyroarytenoid, diaphragm, and masseter) muscles using a competitive PCR assay. An exogenous template that included oligonucleotide sequences specific for seven rat sarcomeric MHC isoforms (β-cardiac, 2A, 2X, 2B, extraocular, embryonic, and neonatal) as well as β-actin was constructed and used as the competitor. Only the extraocular muscle contained all seven isoforms. All seven muscles contained type 2A and type 2X MHC transcripts in varying percentages. As expected, the soleus muscle contained primarily β-cardiac MHC (87.8 ± 2.6%). Extraocular MHC was found only in the extraocular and thyroarytenoid muscles and in relatively small proportions (7.4 ± 1.5% and 4.0 ± 0.7%, respectively). Neonatal MHC was identified in extraocular (7.9 ± 0.3%), thyroarytenoid (4.4 ± 0.4%), and masseter (1.0 ± 0.2%) muscles, and embryonic MHC was identified both in extraocular (1.2 ± 0.5%) and, unexpectedly, in soleus (0.6 ± 0.1%) muscles. Absolute MHC mRNA mass was greatest in the masseter (106 pg/0.5 μg RNA) and least for the tibialis anterior (64 pg/0.5 μg RNA). These values suggest that MHC mRNA represents from 4 to 17% of the total mRNA pool in various skeletal muscles. Differences in MHC profile between somatic and branchial arch muscles suggest that the developmental origin of a muscle may, at least in part, be responsible for the MHC expression program that is implemented in the adult. An inverse relationship between the expression of β-cardiac and type 2B MHC transcripts across muscles was noted, suggesting that the expression of these two isoforms may be reciprocally regulated.

Prognosis of ramsay hunt syndrome presenting as cranial polyneuropathy

Ramsay Hunt syndrome is known to be accompanied with cranial polyneuropathy very occasionally. We reviewed our experience to analyze the clinical manifestations and prognosis of these cases.

Protective effect of Korean red ginseng extract on cisplatin ototoxicity in HEI-OC1 auditory cells.

Ginseng extract is known to have many beneficial effects, including the reversal of pathological and physiological changes induced by ischemia, stress, and aging. Cisplatin, an effective antineoplastic drug, can cause irreversible sensorineural hearing loss and serious tinnitus in humans; thus cisplatin‐induced ototoxicity is a useful experimental model for ototoxicity. This study investigated the protective effects of Korean red ginseng extract on cisplatin‐induced ototoxicity in auditory cells. Pretreatment with 2.5 mg/mL of ginseng extract prior to application of 20 μm of cisplatin significantly increased cell viability after 48 h of incubation in auditory cells. Pretreatment with ginseng extract significantly attenuated the cisplatin‐induced increase in reactive oxygen species (ROS). Ginseng extract also inhibited the expression of caspase‐3 and poly‐ADP‐ribose polymerase related to cisplatin‐induced apoptosis because a major mechanism of cisplatin‐induced toxicity involves ROS production. Thus, Korean red ginseng extract can play both an anti‐apoptotic and anti‐oxidative role on cisplatin‐induced ototoxicity in an auditory cell line. Copyright

Expression of vascular endothelial growth factor in otitis media.

Increased vascular permeability and endothelial cell growth are important in the pathogenesis of otitis media with effusion (OME) and the vascular endothelial growth factor (VEGF) is known to play an important role in the increased vascular permeability and angiogenesis. To date, at least five isoforms of the VEGF family have been identified as VEGF transcripts, encoding polypeptides of 206, 189, 165, 145 and 121, but their physiological roles are unclear. The purpose of this study was to investigate the expression of VEGF, in both endotoxin-induced OME of the rat and human otitis media. We instilled endotoxin and saline as a control into the middle ear cavity of the rat. Middle ear mucosa were taken at 0 h, 1 h, 3 h, 6 h, 12 h, 1 day, 3 days, 7 days and 14 days and the expression of VEGF mRNA and VEGF protein was evaluated using semi-quantitative RT-PCR and immunohistochemistry. Expression of VEGF164 mRNA and VEGF120 mRNA was first identified 1 h after endotoxin instillation and was dramatically increased over the period 6 h-1 day and then progressively decreased by day 7. The level of expression of VEGF120 mRNA was slightly higher than that of VEGF164 mRNA and that of VEGF164 mRNA was much higher than that of VEGF188 mRNA. Immunostaining revealed expression of VEGF during 6 h to day 3 and its expression was localized to ciliated cells and some inflammatory cells. We also performed RT-PCRs of cDNA from middle ear fluids of 8 human OME patients and middle ear mucosa of 4 chronic otitis media patients for the identification of VEGF mRNA expression. VEGF121 mRNA was highly expressed in all samples compared with VEGF165 mRNA. These results suggest that VEGF may be primarily responsible for increased vascular permeability and endothelial cell growth in OME and that VEGF seems to play a significant role in the pathogenesis of OME.

Protective effects of apocynin on cisplatin‐induced ototoxicity in an auditory cell line and in zebrafish

Cisplatin is a very effective anticancer drug and generates reactive oxygen species (ROS) such as superoxide anions that can deplete antioxidant protective molecules in the cochlea. These processes result in the death of cochlear hair cells by induction of apoptosis. Apocynin, which is used as a specific nicotinamide adenine dinucleotide phosphate oxidase inhibitor, has a preventive effect for intracellular ROS generation. In this study, the effect of apocynin was investigated in a cochlear organ of Corti‐derived cell line, HEI‐OC1 cells, and in transgenic zebrafish (Brn3C: EGFP). To investigate the protective effects of apocynin, HEI‐OC1 cells were treated with various concentrations of apocynin and a 20 µm concentration of cisplatin, simultaneously. An in vivo study of transgenic zebrafish (Brn3C: EGFP) was used to investigate the protective effects of apocynin on cisplatin‐induced hair cell death. In an in vitro study, apocynin appeared to protect against cisplatin‐induced apoptotic features on Hoechst 33258 staining in the HEI‐OC1 cells. Treatment of the HEI‐OC1 cells with 100 µm of apocynin, significantly decreased caspase‐3 activity. Treatment of the cells with a 100 µm concentration of apocynin and a 20 µm concentration of cisplatin significantly decreased the intracellular ROS production. In the in vivo study, apocynin significantly decreased the TUNEL reaction and prevented cisplatin‐induced hair cell loss of the neuromasts in the transgenic zebrafish at low concentrations (125 and 250 µm). These findings suggest that apocynin has antioxidative effects and prevents cisplatin‐induced apoptotic cell death in HEI‐OC1 cells as well as in zebrafish. Copyright

Congenital internal auditory canal stenosis.

Congenital internal auditory canal stenosis is a rare cause of sensorineural hearing loss in children. A retrospective analysis including clinical manifestation and radiological findings was made for seven patients who were diagnosed with congenital internal auditory canal stenosis from 1996 to 2002. Chief presenting symptoms were hearing loss, facial nerve palsy, dizziness, and tinnitus. Hearing loss including deafness was found in five cases, vestibular function loss in four cases, and profound functional loss of facial nerve in two cases. In all cases, the diameter of the internal auditory canal was less than 2 mm on high-resolution temporal bone computed tomography (CT) scan. Two cases revealed bilateral internal auditory canal stenosis, and others were unilaterally involved cases. Congenital internal auditory canal stenosis can be an important cause of sensorineural hearing loss, facial nerve palsy, and vestibular dysfunction. High resolution temporal bone CT scan and magnetic resonance (MR) imaging were important tools for diagnosis.

Expression of Mucin Genes in Chronic Ethmoiditis

We have investigated the profiles of MUC genes expressed in chronic ethmoiditis mucosa and normal ethmoid mucosa using RT-PCR, and the morphology of chronic ethmoiditis by a combination of light and electron microscope was observed. In the light- and electron-microscopic studies, chronic ethmoiditis mucosa revealed increased numbers of goblet cells with higher production of mucus in comparison to normal ethmoid mucosa. RT-PCR of cDNAs from three normal ethmoid mucosa revealed the same pattern of mucin gene expression, such as MUC5AC and MUC8. However, RT-PCR of cDNAs from eight chronic ethmoiditis mucosa showed the expression of two MUC1, six MUC4, eight MUC5AC, five MUC5B, seven MUC7, and eight MUC8. MUC2 and MUC6 were not detected. These results suggest that MUC4, MUC5AC, MUC5B, MUC7, and MUC8 are major mucins in the ethmoid mucosa and are up-regulated by chronic inflammation.

Expression of myosin heavy chain mRNA in rat laryngeal muscles

The composition of myosin heavy chain mRNA was analysed quantitatively in 5 intrinsic laryngeal muscles of rats, using a competitive polymerase chain reaction. Intrinsic laryngeal muscles with the fastest contraction times, e.g. ventricular thyroarytenoid muscle. lateral cricoarytenoid muscle. and vocalis muscle, contained 2 fast isoforms, comprising mainly type 2B myosin heavy chains (52.1, 44.6 and 8.2%, respectively) and type 2X myosin heavy chains (21.9, 37.6 and 80.8%, respectively). Conversely, muscles with slower contraction times, such as posterior cricoarytenoid muscle and cricothyroid muscle, contained more than 85% of 2 fast isoforms; mainly type 2X myosin heavy chains (52.4-72.1%, respectively) and type 2A myosin heavy chains (34.6-25.2%, respectively). The results show a strong correlation between the composition of fast myosin heavy chain isoforms and muscle contraction times. Type 2L myosin heavy chain transcripts specific for laryngeal muscles and extra-ocular muscles were expressed in the order of ventricular thyroarytenoid (9.5%) > lateral cricoarytenoid (4.8%) > vocalis (2.5%) > posterior cricoarytenoid muscle (0.9%), but were not expressed in cricothyroid muscle. Neonatal myosin heavy chain was also expressed in all laryngeal muscles, ranging from 0.04 to 3%, but embryonic myosin heavy chain was expressed in ventricular thyroarytenoid, posterior cricoarytenoid and cricothyroid muscle at very low levels. These results suggest that intrinsic laryngeal muscles have different expression patterns for myosin heavy chain isoforms and may have different regulatory roles related to their functional requirement.

Vinegar treatment in the management of granular myringitis.

To compare the therapeutic efficacy in the management of granular myringitis, 15 patients with chronic granular myringitis were treated with antibiotic ear drops that were used twice to four times a day, and another 15 patients were treated with daily irrigation of the external canal with dilute vinegar solution. All patients treated with dilute vinegar solution had resolution of their original otorrhoea within three weeks, whereas two-thirds of patients recovered within three weeks when treated with antibiotic ear drops. The disadvantages of dilute vinegar therapy were canal irritation with pain and dizziness. When the therapeutic efficacy was compared statistically, a dry ear was attained in the dilute vinegar-treated group at six weeks and six months in the antibiotic ear drop treated group (p<0.01). These results suggest that very low pH therapy using dilute vinegar solution is definitely effective in the management of granular myringitis.

A new patch material for tympanic membrane perforation by trauma: the membrane of a hen egg shell

Abstract Conclusion: The egg shell membrane (ESM) patch may promote tympanic membrane (TM) healing in acute traumatic TM perforation. Objective: To evaluate the use of ESM for treating acute traumatic TM perforation. Methods: We reviewed charts of patients with traumatic TM injury from 2008 to 2011. Treatments were an ESM patch or a perforation edge approximation. We divided patients into two groups according to the treatment used. Each patient was matched by treatment onset and perforation size. We compared healing ratio, healing time, and frequency of otorrhea between the perforation edge approximation group and the ESM patch group. Matched t tests were used for analysis. Results: The healing ratio of the TM showed no significant difference between the two groups, but the time to heal was significantly shorter in the ESM patch group than in the perforation edge approximation group.