Measurement of Skull Size on Computed Tomography Images for Developing a Bone Conduction Headset Suitable for the Korean Standard Head Size

Background and Objectives@#We aimed to measure the head dimensions on computed tomography (CT) images, to compare them to directly measured head dimensions, and to predict a new parameter of bone thickness for aiding bone conduction implant (BCI) placement. @*Subjects and Methods@#We reviewed the facial and mandibular bone CT images of 406 patients. Their head sizes were analyzed using five parameters included in the 6th Size Korea project, and they were divided into age groups (ranging from the 10s to the 80s). We compared the head length, head width, sagittal arc, bitragion arc, and head circumference in the CT and Size Korea groups. We also added the parameter bone thickness for aiding BCI placement. @*Results@#All the head size parameters measured using CT were significantly smaller than those measured directly, with head length showing the smallest difference at 7.85 mm. The differences in the other four parameters between the two groups according to patient age were not statistically significantly different. Bone thickness had the highest value of 4.89±0.93 mm in the 70s and the lowest value of 4.10±0.99 mm in the 10s. Bone thickness also significantly correlated with head width (p=0.038). @*Conclusions@#Our findings suggested that the CT and direct measurements yielded consistent data. Moreover, CT enabled the measurement of bone sizes, including bone thickness, that are impossible to measure directly. CT measurements may complement direct measurements in the Size Korea data when used for developing bone conduction hearing devices (BCIs and headsets) for the Korean population.

Morphological Study on the Arterial Intimal Hyperplasia and the Inhibitory Action of Dexamethasone / 체질인류학회지

This study is performed to reveal the changes of the arterial wall, especially, tunica intima and tunica media, after endothelial denudation and the effects of dexamethasone sodium on intimal hyperplasia morphologically in the rat. After arterial denudation by modified air drying technique, dexamethasone 1, 200 mg/kg/day was administered intramuscularly daily from the day of operation for 14 days. At 5 DAT (days after treatment) and 14 DAT, tunica intima was greatly thickened in control groups compared with normal group, but not in the dexamethasone-treated groups. Light microscopically, greatly increased cells and intercellular matrix in the tunica intima are observed in control group, but not in the dexamethasone-treated group. In the TEM observation, the cells considered as myofibroblasts and extracellular matrix were greatly increased in both tunica intima and tunica media just below the internal elastic lamina in the control group. Myofibroblasts and extracellular matrix migrated through the apertures of internal elastic lamina into the endothelial layer. Characteristic false internal elastic lamina also found. In dexamethasone-treated group, myofibroblasts and extracellular matrix decreased significantly, and apoptotic electron-dense cells, fragmented nucleus and autophagic vacuoles are observed. Through the apertures of internal elastic lamina, comma-shaped fragmented nuclei migrated into the tunica intima. These results suggest that dexamethasone inhibits the myofibroblast-transformation and proliferation of smooth muscle cells, migration of myofibroblasts and matrix synthetic activity, and induces the apoptosis of smooth muscle cells under the internal elastic lamina.

Effects of L-Axetidine-2-Carboxylic Acid on Proliferation, Collagen Synthesis and Migration of Cultured Bovine Retinal Pigment Epithelial Cells

Retinal pigment epithelial(RPE) cells play a important role in proliferative retinopathy(PVR) by the collagen production involved in the formation of PVR membrane. To evaluate the effect of L-azetidine-2-carvoxylic acid(LACA), a proline analogue, known as depressing the abnormal cell proliferation and PVR membrane formation, we examined the proliferation, collagen synthesis and migration of cultured bonine RPE cells following the addition of LACA. Differant concentrations of LACA as 1, 10, 50, 100microgram/ml was added to bovine RPE cells and cultured. The cell numbers were measured in 3, 6, 9 days, [3H]-thymidine uptake assay was done to evaluate the change of DNA synthesis, and collagen synthesis and cell migration was measured. The proliferation of PRE cells treated with LACA were significantly inhibited in a concentration and time dependant manner. [3H]-thymidine uptake and collagen synthesis of RPE migration was also significantly inhibited in proportion to the concentration. The results reveal that LACA has an inhibitory effect on cell proliferation, collagen synthesis and migration of bovine retinal pigment epithelial cells. It also suggest that the use of LACA to suppress membrane formation in the eyes with PVR can be possible.

Clinical Rdsults of Rigid Gas Permeable Contact Lens Wearing Patients

To know the clinical results of recently widely used rigie gas permeable(RGP) contact lens, we evaluated the actual fitting conditions of the RGP lenses of 512 patients(874 eyes) with questionnaire and regular follow up from August 1993 to December 1995 on the Eye Clinic of Kangnam St. Mary's Hospital. All Patients were the first users of the RGP contact lens. The RGP contact lens wearing rate was higher in 1995 than in 1993. Satisfaction of the RGP contact lens wearing was better. Previous hard contact lens users were satisfied most and previous soft lens users couldn't adapt to the RGP contact lens than the first users. Most patients wanted the periodic examinations, but they couldn't have because of insufficiency of time. The side effect rate was lower than that of previously used lenses, and the most important problem in wearing condition was discomfort as foreign body sensation and easy damage of contact lens. In these results, the role of th ophthalmologist for the proper RGP contact lens fitting, the patient's education and practice are required.

The Effects of Amrinone and Milrinone on Myocardium in the Isolated Isoflurane-Exposed Rat Heart / 대한마취과학회지

BACKGROUND: The aims of this study were to test if amrinone or milrinone reverses cardiac depression induced by the exposure to isoflurane in the isolated heart and to determine whether amrinone or milrinone dilates the coronary artery directly. METHODS: Using the isolated Sprague-Dawley rat hearts, heart rate, left ventricular pressure, dp/dt (differentiated rate of pressure development), O2 delivery(DO2), myocardial oxygen consumption(MVO2), and percent O2 extraction were measured. After the isolated hearts were exposed to isoflurane at 1.2 vol% during 10 min, amrinone(10, 50, 100 M) or milrinone(1, 5, 10 M) was separately given to six groups. RESULTS: Amrinone and milrinone reversed, not statistically significant, the depression of cardiac contractility induced by isoflurane, while the isoflurane-induced bradycardia substantially returned to normal by amrinone 100 M. And amrinone and milrinone elevated coronary flow, DO2, MVO2, while isoflurane increased in coronary flow and DO2, except MVO2. CONCLUSIONS: These results suggest that amrinone and milrinone did not counteract the isoflurane-induced cardiac depression and indirectly increased in coronary blood flow through the elevation of cardiac work.

Culture of Bovine Retinal Pigment Epithelium: Topographical Differences of Morphology and Growth Rate in Vitro

Cell cultures of adults bovine retinal pigment epithelium(RPE) were propagated from central and peripheral regions of the same eyes to study the topographical differences in cell growth and to compare the differences in growth rate between two areas. The results obtained were as follows: A regional variation in the morpholgy was observed between the RPE from central and that from peripheral regions. Retinal pigment epithelium from central region attached to culture dish more slowly(average 4 days) than those from peripheral region(average 3.5 days) The growth rate of retinal pigment epithelium declined with serial passage in culture. The growth rate of retinal pigment epithelium from peripheral region at the first generation was highest. And there was a statistical difference in growth rate with passing in generation(P<0.05). This study reveals that growth rate and cell activity of RPE from central region are lower than from peripheral region.

Heart size in new-born infants

Cardiac size of 291 new-born infants was measured using the method illustated on Fig 1. Among the 291 infants,53 were asphyxiated, and asphxia was only regared from Apgar score below 6 on 1 min. and 5 min. Remaining 238infants were normal, and classified to group with lung abnormalities and without lung abnormalities on chest A-Pfilm. The results are as follows; 1. The average CTR. of normal group was 52.37(C/T1;54.89, C/T2;49.43, C/T3;49.15, C/T;55.97) 2. The average CTR. of asphxiated group was 54.91 (C/T1;57.13, C/T2;51.69, C/T3;51.94,C/T4;58.25) 3. Consequently, asphyxiated infants revealed larger cardiac size than normal infant group.

A radiologic analysis and comparative evaluation of hysterosalpingographic and laparoscopic findings ininfertile patients

Hysterosalpingograms of 375 patients with infertility were reviewed with reference to radiological features of each pathology and a comparative study of hysterosalpingography and laparoscopy in 36 patients was presented. The results were as follows; 1. In 375 cases infertility, 191 cases (50.9%) were primary infertility and 181 cases(49.1%) were secondary infertility. 2. The peak age distribution was 26 to 30 year old group in 211 cases (56.3%),and the peak duration of infertility was less than 3 years in 256 cases (68.3%). 3. Abnormal uterine findings were 115 cases (30.7%) and there were 73 cases of filling defects, 13 cases of irregularity , 12 cases of uterineflexion, 11 cases of congenital anomaly, and 9 cases of hypoplasia among them. 4. Abnormal tubal findings were 196 cases (52.3%) and there were 103 cases of simple obstruction, 69 cases of hydrosalpinx, and 50 cases of peritubal adhesion among them. 5. Intravasation of contrast media was noted in 42 cases (11.2%). 6. In 36 cases of laparoscopy, 23 cases (63.7%) was agreed to hysterosalpingography. 7. Aothough laparoscopy was better than hysterosalpinography in external anatomy of salpinx and relationship to overay, hysterosalpingography should be important for fundamental study of infertile women because of lower failure rate, lower risk of complications,therapeutic effect, and lower cost.