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Biomedical subjects

M S Chung

Publications and source records attributed to M S Chung.

46 records · Page 3Linked to original sources

Development of face recognition.

In this article, research findings from studies which have examined the developmental pattern for recognition of unfamiliar faces and relevant theories are reviewed. Recognition of faces was found to improve with age from about five years to adulthood, with some studies reporting a dip during early adolescence. Two neuropsychological explanations (development of hemisphere specialization and maturational changes) and four information processing explanations (depth of face processing, pattern of feature salience, development of face schema, and encoding shift) are described and assessed for their tenability in light of reported findings. Explanations for the developmental dip are also discussed. Since these explanations failed to receive sufficient empirical support, an alternative explanation in terms of increasing efficiency of encoding is proposed.

Adolescent↗

Locational relationship of the supraorbital notch or foramen and infraorbital and mental foramina in Koreans.

The morphology and locational relationship of the supraorbital notch/foramen, infraorbital foramen, and mental foramen were studied from photographs of 124 Korean skulls (male 35, female 18, unknown sex 71). The infraorbital foramen was on the sagittal plane passing through the supraorbital notch/foramen (36.4%), or lateral to the plane (63.6%). The mental foramen was either on the plane (69.3%), lateral to the plane (21.8%), or medial to the plane (9.0%). The supraorbital notch/foramen, infraorbital foramen, and mental foramen were on the same sagittal plane in 38.1% of the cases. The supraorbital notch (69.9%) was found more frequently than the supraorbital foramen (28.9%). The average distance from the median plane to the center of the supraorbital notch/foramen, infraorbital foramen, and mental foramen was 22.7, 27.2 and 24.4 mm, respectively. The average length of the line from the center of the supraorbital notch/foramen to the center of the infraorbital foramen was 45.6 mm, and the angle of this line to the sagittal plane was 5.8 degrees. The average distance from the infraorbital margin to the center of the infraorbital foramen was 8.6 mm, and that from the inferior margin of mandible to the center of the mental foramen was 15.5 mm in males and 14.0 mm in females. The average horizontal width of the supraorbital notch/foramen, infraorbital foramen, and mental foramen was 4.7, 4.8 and 2.4 mm, respectively. Most commonly, the infraorbital foramen was lateral to the sagittal plane of the supraorbital notch/foramen, and the mental foramen was on that plane. This locational relationship would be helpful clinically to determine the location of the infraorbital and mental foramina, by palpation of the supraorbital notch.

Adolescent↗

Study on the Korean adult cranial capacity.

Cranial capacity was measured in Korean adult skulls. The cavity was filled with rice seeds and the volume of the seeds were measured in a graduated cylinder. The results were 1470 +/- 107 (mean +/- standard deviation) in male and 1317 +/- 117 cc in female skulls. These values were in good accordance with those previously reported. In addition, regression formulae were obtained with the product of the length, breadth, and height of the skull as an independent parameter and the measured capacity as a dependent one. With known external measurements, the expected cranial capacity was as follows: when using baso-bregmatic height, male: capacity = 307.5 + 333 x 10(-6) x (length.breadth.baso-bregmatic height) female: capacity = -12.0 + 435 x 10(-6) x (length.breadth.baso-bregmatic height) and, when using auriculo-bregmatic height, male: capacity = 214.6 + 429 x 10(-6) x (length.breadth.auriculo-bregmatic height) female: capacity = 131.6 + 461 x 10(-6) x (length.breadth.auriculo-bregmatic height).

Adult↗

A comparison of the passage of regenerating axons through old degenerated nerve autografts and fresh nerve autografts in rats.

We have compared the passage of regenerating axons through old degenerated nerve autografts and fresh nerve autografts in two groups of Sprague Dawley rats. In one group the right sciatic nerve was divided and repaired with the graft taken from the distal segment of the left sciatic nerve, which had been severed 15 weeks before. In the other group the right sciatic nerve was repaired with the graft taken from the intact left sciatic nerve. Eight weeks later the myelinated axons were counted at three different locations in the grafted right sciatic nerve in both groups. The old degenerated nerve autografts were less effective in allowing the passage of regenerating axons than the fresh nerve autografts, but the difference was not great. This provides justification for the use of old degenerated nerve as an additional graft where a large number of autogenous nerve grafts are required, such as in the operative treatment of injuries to the brachial plexus.

Animals↗

Periandrin V, a further sweet triterpene glycoside from Periandra dulcis.

A new sweet triterpene glycoside, periandrin V, was isolated from the roots of Periandra dulcis and identified as 3 beta-O-[beta-D-xylopyranosyl-(1-->2)-beta-D-glucuronopyranosyl]-25 -al-olean-18(19)-en-30-oic acid on the basis of chemical and spectral evidence. The structure of an acid-rearranged product of periandrin V and the parent compound, periandrin I, was determined as 1(10-->25) abeo-3 alpha, 25 alpha-epoxy-olean-5(10), 18-dien-30-oic acid methyl ester.

Carbohydrate Sequence↗

Selligueain A, a novel highly sweet proanthocyanidin from the rhizomes of Selliguea feei.

Selligueain A, a novel sweet trimeric proanthocyanidin with a doubly linked A unit, has been isolated from the rhizomes of Selliguea feei collected in Indonesia. The structure of this substance was established as epiafzelechin-(4 beta-->8, 2 beta-->O-->7)-epiafzelechin-(4 beta-->8)-afzelechin [1], on the basis of a combination of spectral and chemical methods. The compound was not acutely toxic for mice and not mutagenic in a forward mutation assay utilizing Salmonella typhimurium strain TM677. Selligueain A [1] was rated by a taste panel as exhibiting about 35 times the sweetness intensity of a 2% w/v aqueous sucrose solution, and at a concentration of 0.5% w/v in H2O was perceived as pleasant-tasting rather than astringent.

Animals↗

[Analysis of antigenic specificities of Paragonimus westermani developmental stages using immunoblot technique].

Serodiagnosis of parasitic infections is widely used, since parasites or their eggs are not always detected by ordinary methods. The sensitive tests such as ELISA are highly dependent on the purity of antigens used. To solve this problem, many workers have tried to find species-specific components of antigens. The present study was performed to determine the antigenic profile of crude saline extracts of 3, 5, 8 and 12-week old P. westermani worms, which were collected from experimentally infected cats, based on SDS-PAGE and immunoblot technique. The results were as follows: 1. The SDS-PAGE showed at least 30 protein bands ranging from 229 kDa to 10 kDa molecular weight. The protein components of P. westermani changed chronologically during its developmental period. The 229 kDa band was recognized only in 12-week old worms (SEP12). 2. Analysis by ELISA showed a significant increase in antibody levels at 3 weeks in infected cats using crude saline extract antigens (SEP3, SEP5, SEP8, SEP12). 3. By EITB using SEP3 and SEP5, infected cats recognized major protein bands with molecular weight of 60, 35, 28, 25 or 21 kDa at 3-12 weeks of infection, and 3 additional antigens, 19, 13 and 10 kDa, were detected at 8-12 weeks of infections. 4. Using SEP8, 5 antigens, 91, 85, 31, 25 and 21 kDa, were consistently detected by all infected sera tested. In addition, 3 antigens of 19, 13 and 10 kDa were detected at 8-12 weeks of infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Demonstration of species-specific and cross reactive components of Paragonimus westermani crude worm antigen by EITB.

Enzyme-linked immunoelectrotransfer blot (EITB) using crude worm antigen of adult Paragonimus westermani was performed for human patients sera to identify the species-specific components. Crude antigen was obtained by homogenizing and centrifuging 24-week old adult worms at 10,000 rpm for 60 minutes in phosphate buffered saline (PBS, pH 7.2) containing phenyl methyl sulfonyl fluoride (PMSF). Gradient sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was performed and blotted electrophoretically onto a sheet of nitrocellulose paper. The sheet was cut into strips and exposed to sera diluted 1: 200 with PBS. SDS-PAGE showed 26 protein bands ranging 229 to 10 kDa. Of them 229, 91, 60, 50, 35-31, 27, 25, 21, 17, 11 and 10 kDa components showed positive reaction with serum antibody of patients with P. westermani. Sera of patients infected with Clonorchis sinensis reacted with 35-31, 19, and 11 kDa bands. Human sera from cysticercosis and diphyllobothriasis cases showed non-specific cross reactions with 229, 35-31, 27, 25 and 17 kDa bands. Protein bands of 91, 60, 21 and 10 kDa showed strong positive reaction without cross reactions with sera from other helminthic infections.

Animals↗

Metatarsal lengthening in congenital brachymetatarsia: one-stage lengthening versus lengthening by callotasis.

We retrospectively reviewed and compared the outcomes of 15 one-stage metatarsal lengthenings with intercalary bone graftings in 10 patients with those of nine metatarsal lengthenings by callotasis in five patients younger than 15 years. In the one-stage lengthening group, the diaphyseal osteotomy site was gradually distracted intraoperatively for 20-30 min to relax the surrounding soft tissues. In the callotasis group, lengthening was achieved with mini-Orthofix M-100. There was little difference in the outcomes between the two groups in terms of length gain, percentage increase, and complications. However, the period to achieve bony consolidation was longer in the callotasis group (2.7 months/cm) than in the one-stage lengthening group (1.5 months/cm). No case of neurovascular impairment was found in both groups.

Adolescent↗