Designing Tyrosinase siRNAs by Multiple Prediction Algorithms and Evaluation of Their Anti-Melanogenic Effects

Melanin is a pigment produced from tyrosine in melanocytes. Although melanin has a protective role against UVB radiation-induced damage, it is also associated with the development of melanoma and darker skin tone. Tyrosinase is a key enzyme in melanin synthesis, which regulates the rate-limiting step during conversion of tyrosine into DOPA and dopaquinone. To develop effective RNA interference therapeutics, we designed a melanin siRNA pool by applying multiple prediction programs to reduce human tyrosinase levels. First, 272 siRNAs passed the target accessibility evaluation using the RNAxs program. Then we selected 34 siRNA sequences with ΔG ≥−34.6 kcal/mol, i-Score value ≥65, and siRNA scales score ≤30. siRNAs were designed as 19-bp RNA duplexes with an asymmetric 3′ overhang at the 3′ end of the antisense strand. We tested if these siRNAs effectively reduced tyrosinase gene expression using qRT-PCR and found that 17 siRNA sequences were more effective than commercially available siRNA. Three siRNAs further tested showed an effective visual color change in MNT-1 human cells without cytotoxic effects, indicating these sequences are anti-melanogenic. Our study revealed that human tyrosinase siRNAs could be efficiently designed using multiple prediction algorithms.

Comparison of alpha-synuclein immunoreactivity in the spinal cord between the adult and aged beagle dog / 한국실험동물학회지

Alpha-synuclein (alpha-syn) is a presynaptic protein that is richly expressed in the central and peripheral nervous systems of mammals, and it is related to the pathogenesis of Parkinson's disease and other neurodegenerative disorders. In the present study, we compared the distribution of the immunoreactivity of alpha-syn and its related gliosis in the spinal cord of young adult (2-3 years) and aged (10-12 years) beagle dogs. We discovered that alpha-syn immunoreactivity was present in many neurons in the thoracic level of the aged spinal cord, however, its protein level was not distinct inform that of the adult spinal cord. In addition, ionized calcium-binding adapter molecule-1 (a marker for microglia) immunoreactivity, and not glial fibrillary acidic protein (a marker for astrocytes) immunoreactivity, was somewhat increased in the aged group compared to the adult group. These results indicate that alpha-syn immunoreactivity was not dramatically changed in the dog spinal cord during aging.

A Refinement System for Medical Information Extraction from Text.based Bilingual Electronic Medical Records / 대한의료정보학회지

OBJECTIVE: Applications to extract medical information from electronic medical records(EMRs) confront some serious obstacles such as spelling errors, ambiguous abbreviations, and unrecognizable words. Those obstacles hinder the process of finding medical entities, relations, and events. We present an efficient EMR refinement system for the purpose of medical information extraction from EMRs, not just for traditional text error correction. METHODS: The EMR refinement system has been designed and implemented through following steps: 1) Build domain constrained dictionary database, 2) Correct spelling errors in Korean-English EMR documents, 3) Resolve ambiguous abbreviations in the bilingual documents. The resulting EMR documents are now machine readable and can be applied to various applications including information extraction. RESULT: Precision rate of the refinement system for spelling error correction is 80.4% and for disambiguating abbreviations/acronyms is 94.7%. CONCLUSION: We developed an EMR refinement system to correct spelling errors and resolve ambiguous abbreviations as well as unrecognizable words. Our system can enhance the reliability of medical records and contribute to develop further application systems in the field of text mining and information extraction.

Changes in orexin-A and neuropeptide Y expression in the hypothalamus of the fasted and high-fat diet fed rats

This study was aimed to investigate the changes of orexin-A (OXA) and neuropeptide Y (NPY) expression in the hypothalamus of the fasted and high-fat diet fed rats. For the experiments, the male Sprague-Dawley (SD) rats were used as the model of high-fat diet-induced obesity. The mean loss of body weight (MLBW) did not show the linear pattern during the fasting; from 24 h to 84 h of fastings, the MLBW was not significantly changed. The numbers of OXA-immunoreactive (IR) neurons were decreased at 84 h of fasting compared with those in other five fasting subgroups. The NPY immunoreactivities in the arcuate nucleus (ARC) and the suprachiasmatic nucleus (SCN) observed at 84 h of fasting were higher than that observed at 24 h of fasting. The number of OXA-IR neurons of the LHA (lateral hypothalamic area) in the high-fat (HF) diet fed group was more increased than that of the same area in the normal-fat (NF) diet fed group. The NPY immunoreactivities of the ARC and the SCN were higher in HF group than those observed in the same areas of NF group. Based on these results, it is noteworthy that the decrease of the body weight during the fast was not proportionate to the time-course, implicating a possible adaptation of the body for survival against starvation. The HF diet might activate the OXA and the NPY in the LHA to enhance food intake.

Histochemical Electron Microscopic Findings of the Distribution of the Glycosaminoglycans of Cultured Sensory Retina

PURPOSE: This study was performed to investigate the distribution of glycosaminiglycans by the activated retinal neuronal cell on the cultured retinal tissue. METHODS: The retinal tissue was obtained from the donor eyeball without the pathological findings of the retina. The dissected retinal tissue was cultured for 2 weeks in the culture media and reacted with ruthenium red dye to observe the glycosaminoglycans reaction with transmission electron microscopy. RESULTS: The histochemical reaction to ruthenium red on the cultured retina tissue was prominent on the internal limiting membrane, intercellular space between the axons and dendrites at the outer and inner plexiform layers and interphotoreceptor matrix. CONCLUSIONS: These findings suggest that GAGs may be released into the extracellular spaces between the axons and dendrites, which modulate the retinal circuits.

Intraocular Lens Power Calculation for Cataract Surgery in Patients who had Previous Refractive Surgery (RK 1 Case, PRK 3 Cases, LASIK 1 Case)

The purpose of this study is to assess the accuracy of IOL power calculations using clinical history method in patients who undergo cataract surgery after previous PRK, RK, or LASIK.Five eyes of 3 patients who had previous PRK, RK, or LASIK underwent phacoemulsifications with IOL implantation.We calculated IOL power for target refractive error using clinical history method.We compared postoperative refractive error to target refractive error at 3 months after cataract surgery.In the first case (RK (od)& PRK (os)), there was 3.50 diopter undercorrection on the right eye and IOL was exchanged.And target refractive error was achieved on the left eye.In the second case (LASIK patient)there was 1.00 diopter undercorrection.In the third case (PRK (ou)), right eye achieved 0.75 diopter undercorrection and left eye achieved 0.50 diopter overcorrection.The types of cataract were nuclear sclerotic in 3 cases and anterior subcapsular in 2 cases.To determine the exact IOL power after refractive surgery, using clinical history method would be good alternative in these patients.

Effects of histamine H|2-receptor stimulation on Mg2+ efflux in perfused guinea pig heart

Mg2+ is an important regulator of many cardiac functions. However, regulation of intracellular Mg2+ activity in the heart is not well characterized. To assess the effect of histamine H2-receptor stimulation on intracellular Mg2+ regulation, changes in extracellular Mg2+ concentration were examined under a variety of conditions in perfused guinea pig hearts. Mg2+ in the cardiac perfusate was measured by atomic absorbance spectrophotometry. The histamine (10(-6) M induced a marked Mg2+ efflux from the heart. The H2-receptor antagonists, cimetidine (10(-5) M), ranitidine (10(-5) ND, but not a H1-receptor antagonist, diphenhydramine (3 X 10(-6) M), completely blocked the histamine-induced Mg2+ efflux. The Mg2+ efflux could also be induced by forskolin (3 X 10(-6) M), 8-Cl-cAMP (2 X 10(-4) M), permeable cAMP analogue, or dimaprit, (10(-5) M). However, the carbachol (10(-5) M) considerably decreased the efflux of Mg2+. In the presence of papaverine (10(-5) M), a phosphodiesterase inhibitor, dimaprit-induced Mg2+ efflux was potentiated. These results suggest that a significant Mg2+ efflux from perfused guinea pig heart by histamine can be induced by the histamine H2-receptor stimulation and it is suggested that cytosolic cAMP may be linked.

Regulation of Mg2+ release in guinea pig heart and isolated ventricular myocytes by alpha1-adrenergic stimulation

Mg2+ is the fourth most abundant cation in cellular organisms. Although the biological chemistry and the physiological roles of the magnesium ion were well known, the regulation of intracellular Mg2+ in mammalian cells is not fully understood. More recently, however, the mechanism of Mg2+ mobilization by hormonal stimulation has been investigated in hearts and in myocytes. In this work we have investigated the regulation mechanism responsible for the Mg2+ mobilization induced by alpha1-adrenoceptor stimulation in perfused guinea pig hearts or isolated myocytes. The Mg2+ content of the perfusate or the supernatant was measured by atomic absorbance spectrophotometry. The elimination of Mg2+ in the medium increased the force of contraction of right ventricular papillary muscles. Phenylephrine also enhanced the force of contraction in the presence of Mg2+/-free medium. alpha1-Agonists such as phenylephrine were found to induce Mg2+ efflux in both perfused hearts or myocytes. This was blocked by prazosin, a alpha1-adrenoceptor antagonist. Mg2+ efflux by phenylephrine was amplified by Na+ channel blockers, an increase in extracellular Ca2+ or a decrease in extracellular Na+. By contrast, the Mg2+ influx was induced by verapamil, nifedipine, ryanodine, lidocaine or tetrodotoxin in perfused hearts, but not in myocytes. W7, a Ca2+/calmodulin antagonist, completely blocked the phenylephrine-, A23187-, veratridine-, Ca2+/-induced Mg2+ efflux in perfused hearts or isolated myocytes. In addition, Mg2+ efflux was induced by W7 in myocytes but not in perfused heart. In conclusion, An increase in Mg2+ efflux by alpha1-adrenoceptor stimulation in hearts can be through IP3 and Ca2+/-calmodulin dependent mechanism.

Appearance of Polymorphonuclear Leukocytes Following Corneal Scratching Wound by Impression Cytology

The linear scratching wound was made gently on the corneal epithelium of rabbit with 21 gauge needle under an operating microscope. Impression cytology was performed at 30 minutes, 1, 2, 3 and 4 hour and 1, 2, 3 and 4 day after 0.5% tetracaine drops under an operating microscope. The filter paper was stained with hematoxylin and eosin. At 30 minute post-scratching, a few polymorphonuclear leukocytes appeared on the scratched cornea at 3 eyes (30%). At 3 and 4 hour, numerous polymorphonuclear leukocytes with corneal epithelial cells appeared on the scratched conea. By 3 day, no inflammatory cells were shown on the filter paper in all eyes. These findings suggest that the polymorphonuclear leukocytes could infiltrate on the corneal lesion at 30 minute post-scratching and the inflammatory cells might act even on the minute corneal lesion such as corneal erosion.

Comparison of Intraocular Pressure Measurements of Tono-Pen and Perkins Tonometer in Children Under the General Anesthesia

Tono-pne and Perkins tonometer have been widely accepted to measure the intraocular pressure(IOP) of children under the general anesthesia because of their portability. We evaluated the difference of IOP between two devices and the IOP variability in 39 children(77 eyes) under age 13 who had undergone surgery for strabismus or entropin under the general anesthesia. One observer measured the IOP three times alternately, and the order of measurement was randomized. Only 5% of Tono-pens coefficient of variance was considered valuable. The range of Tono-pen IOPs was 9~22mmHg, and the average was 15.41+/-3.23mmHg. The range of Perkins IOPs was 4~20 mmHg, with the average of 12.47+/-3.31mmHg. The difference between two methods on average was 2.94mmHg. Tono-pen IOPs were significantly greater than those recorded by Perkins tonometer, but both were within normal range. The IOP variability was not significantly different between two devices. Therefore both methods can be applied effectively in a clinical setting after sedation or general anesthesia of uncooperative children.

Effects of Hyperosmolar Solution on the Twitch Force, Membrane Potential, and Intracellular Sodium Activity in Purkinje Fibers and Ventricular Muscles

BACKGROUND: Hypertonic solutions are using in emergency patients including refractory shock. The effects of the hyperosmotic solutions for the cardiac contractile effect has remained unclear. To study the mechanism of increase in twitch force by hypertonic solution, memberane potential, intracellular sodium activities(aNia), and twitch force were measured simultaneously in 1 Hz-driven canine Purkinje fibers and guinea pig papillary muscles. METHODS: To increase osmolarity, 20, 40, and 80 mOsm glucose, NaCl or mannitol was added to normal Tyrode solution. We used the conventional and Na(+)-selective microelectrodes, to study the membrane potential and intracellular sodium activity. Changes in twitch force were evaluated also by tension tranducer. RESULTS: 1) Hyperosmolar glucose or NaCl added to normal Tyrode solution produced membrane pontential hyperpolarization, increase in aNia, and increase in twitch force in dog Purkinje fibers. Increase in twitch force was related to decrease in the ratio of aNia to extracellular sodium activity(aNoa). NaCl-inducedd aNia increase was not blocked by 10(-5)M tetrodotoxin, a fast sodium channel blocker. 2) Hyperosmolar glucose or mannitol added to normal Tyrode solution produced membrane potential hyperpolarization, increase in aNia, and increase in twitch force in guinea pig papillary muscles. However, the addition of hyperosmolar NaCl did not affect on membrane potential, but produced increase in aNia, and decrease in twitch force. 3) Prolonging effect of hyperosmolar glucose on duration of action potential was smaller than that of NaCl or mannitol in Purkinje fibers and papillary muscles. 4) Increase in twich force produced by ECF Na+reduction or by hyperosmotic solution was reated to decrase in the aNia ratio. 5) Relationship curve between increase in twitch force and aNoa/aNia ratio in hyperosmolr solution was less steeper than that in ECF Na(+)-reduced solution. CONCLUSION: The above results suggested that hyperosmolar solution-induced twitch force change was related to aNoa/aNia ratio change which influenced intracellular calcium activity via Na(+)-Ca(2+)exchange.

Anatomical studies on the cardiac skeleton of the Korean native goat / 대한해부학회지

No abstract available.