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Biomedical subjects

S S Cho

Publications and source records attributed to S S Cho.

43 records · Page 3Linked to original sources

Immunocytochemical study with an anti-transferrin binding protein serum: a marker for avian oligodendrocytes.

We have investigated immunocytochemically the localization of a transferrin binding protein (TfBP) in adult CNS of avian and mammalian species using a polyclonal antibody raised against the protein purified from hen oviduct membranes (alpha OV-TfBP). TfBP has recently been shown to be HSP108. An overall strong immunoreactivity was revealed in most parts of the avian brains, especially in the white matter. The main immunoreactivity originated in small, intensely reacting cells interpreted as oligodendrocytes. The density of TfBP-labeled oligodendrocytes of the avian brains was generally proportional to the degree of myelination. There were no marked differences in TfBP-immunostaining pattern between avian species (chick, pigeon and lovebird). On the other hand, in rat, rabbit and cat brains we could not find any TfBP-immunoreactivity. Immunoelectron microscopy has further revealed that TfBP is present in the light and medium types of oligodendrocytes which are known to have high metabolic activities. TfBP reaction product was homogeneously dispersed throughout the perinuclear cytoplasm and fine processes of oligodendrocytes. The intracytoplasmic organelles such as mitochondria and Golgi apparatus were devoid of reaction product. The presence of TfBP in oligodendrocytes implies that this protein may play an important role in transferrin-mediated iron metabolism in the CNS. The complete lack of cross-reactivity between alpha OV-TfBP and mammalian tissues suggests that there is species variability in TfBP structure. We conclude that this chick TfBP antiserum will prove useful in studies of oligodendrocytes and myelination in the avian CNS.

Animals↗

Anatomical observation on draining patterns of saphenous tributaries in Korean adults.

This study was done to identify the normal and variants of saphenous tributaries in Korean adults. The pattern of confluence of saphenous tributaries, medial accessory saphenous, lateral accessory saphenous, superficial epigastric, superficial circumflex iliac and superficial external pudendal veins, was carefully examined in 249 lower limbs (right, 129; left, 120) of embalmed Korean cadavers (73 males & 56 females). The medial accessory saphenous vein drained into the great saphenous vein directly (in 82.3%) or by a common trunk (in 17.7%) with the superficial epigastric or superficial external pudendal vein. The lateral accessory saphenous vein entered the great saphenous (in 67.1%) or the femoral vein (in 32.9%) directly or, forming a common trunk with other saphenous tributaries. The superficial epigastric vein joined the great saphenous (in 77.1%) or the femoral vein (in 22.9%) directly or, by a common trunk with other saphenous tributaries. The superficial circumflex iliac vein reached the great saphenous (in 83.1%) or the femoral vein (in 16.9%) directly or, by a common trunk with other saphenous tributaries. The superficial external pudendal vein opened into the great saphenous (in 95.2%) or the femoral vein (in 4.8%) directly or by a common trunk with other saphenous tributaries. In Koreans, the incidence of the normal pattern of saphenous tributaries was 23.7% and in 76.3% any one of variant saphenous tributaries entered the femoral or the great saphenous vein by a common trunk with other saphenous tributaries.

Adult↗

Spinal bone mineral density of normal and osteoporotic women in Korea.

In order to define osteoporosis on the basis of bone mineral measurements, one must define an acceptable normal range or fracture threshold. It is clear that the normal range cannot be compared between different ethnic groups. We have measured spinal bone mineral density (BMD) by dual photon absorptiometry in 277 women without spinal fracture, aged 30-91 years, and in 53 women with asymptomatic spinal fracture to provide such a database for normal Korean women. Peak bone mass at the 3rd decade was 1.24 g/cm2. BMD from age 40-69 was strongly correlated with age (r = -0.7) and the annual decrease averaged 0.018gm/cm2. The rate of annual loss slowed by 50% in women after 70% years of age. Fracture threshold was evaluated at the 90th percentile for spinal BMD in patients with vertebral fractures. The fracture threshold of the vertebra was 0.94 g/cm2. Approximately 50% of normal women over 50 years of age had values below this threshold. These findings suggest that the way of developing low bone mass in Korean women is to peak high and lose fast.

Adult↗

The ontogeny of transferrin receptors in the embryonic chick retina: an immunohistochemical study.

Transferrin receptor (TfR) immunoreactivity in the developing chick retina was examined. Immunoreactivity was detectable in the ganglion cells of embryonic day (E) 4 retina. At E9, diffuse TfR immunoreactivity appeared in the outer portion of the inner nuclear layer. Amacrine cells were the most intensely TfR-positive cells in the inner nuclear layer. At E11, the inner segment of photoreceptor cells showed moderate immunoreactivity. With the appearance of the outer segments, positive immunoreactivity was observed in these structures. TfR's developmental distribution in the retina may reflect the developmental and physiological role of transferrin.

Animals↗

Cholesterol synthesis is required for cutaneous barrier function in mice.

Previous studies have shown that topical acetone treatment results in the removal of stratum corneum lipids and disruption of the permeability barrier. This disruption stimulates epidermal lipid synthesis which is associated with the rapid restoration of stratum corneum lipids and barrier function. The aim of this study was to determine the role of cutaneous cholesterol synthesis in the barrier recovery. Here we show that topical lovastatin, a competitive inhibitor of HMG CoA reductase, inhibits cholesterol synthesis. After acetone disruption of the barrier, the normal rapid return of cholesterol to the stratum corneum and recovery of barrier function is impaired in animals treated topically with lovastatin. When lovastatin animals are simultaneously treated topically with either mevalonate, the immediate product of HMG CoA reductase, or cholesterol, the final end product of the pathway, the recovery of the barrier is normalized. Lovastatin resulted in the delayed secretion and abnormal appearance of lamellar bodies. These results provide the first evidence demonstrating that cholesterol synthesis is required for the maintenance of barrier structure and function and suggests a crucial role for cholesterol synthesis in allowing for terrestrial existence.

Animals↗

A high-fat diet does not influence the growth of the Dunning R3327-H transplantable prostate adenocarcinoma.

BACKGROUND: The etiology of prostate cancer is currently a mystery. Several epidemiological studies suggest a link between dietary fat and prostate cancer. In vitro and in vivo studies support this evidence. Using the Dunning model of rat prostate cancer we hypothesized that a high-fat diet (20%) would increase the growth of the R3327-H tumor. MATERIALS AND METHODS: R3327-H tumors were implanted subcutaneously into male Copenhagen rats which were fed diets with 5 or 20% total fat. Tumors were allowed to grow for 16 weeks; they were then excised and weighed. The initial and final weights of the rats were also recorded. RESULTS: Statistical analysis revealed the level of dietary fat was a positive predictor of weight gain (p < 0.01). No effect on tumor growth was seen when compared to dietary fat, fiber type, or the interaction of fat and fiber. DISCUSSION: Growth of the R3327-H tumor, when implanted subcutaneously, is not affected by the level of dietary fat.

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