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Biomedical subjects

S Jeong

Publications and source records attributed to S Jeong.

46 records · Page 3Linked to original sources

Micrococcal nuclease digestion of nuclei reveals extended nucleosome ladders having anomalous DNA lengths for chromatin assembled on non-replicating plasmids in transfected cells.

The chromatin structures of a variety of plasmids and plasmid constructions, transiently transfected into mouse Ltk- cells using the DEAE-dextran procedure, were studied by micrococcal nuclease digestion of nuclei and Southern hybridization. Although regularly arranged nucleosome-like particles clearly were formed on the transfected DNA, the nucleosome ladders, in some cases with 13-14 bands, were anomalous. Most often, a ladder of DNA fragments with lengths of approximately 300, 500, 700, 900 bp, etc. was generated. In contrast, typical 180-190 bp multiples were generated from bulk cellular or endogenous beta-actin gene chromatin. Very similar results were obtained with all DNA's transfected, and in a variety of cell lines, provided that plasmid replication did not occur. Additionally, after digestion of nuclei, about 90% of the chromatin fragments that contained transfected DNA sequences could not be solubilized at low ionic strength, in contrast with bulk cellular chromatin, suggesting association with nuclear structures or nuclear matrix. The remaining 10% of transfected DNA sequences, arising from soluble chromatin fragments, generated a typical nucleosome ladder. These results are consistent with the idea that assembly of atypical chromatin structures might be induced by proximity to elements of the nuclear pore complex or by nuclear compartmentalization.

Animals↗

A follow-up study using iodine-131 metaiodobenzylguanidine imaging in a patient with neuroblastoma.

A new radiopharmaceutical, I-131 metaiodobenzylguanidine (I-131 MIBG) was used to determine the location and to follow-up tumors in a 13-month-old girl with neuroblastoma. I-131 MIBG imaging revealed both a primary abdominal tumor and a distant metastatic orbital tumor. Follow-up study with I-131 MIBG imaging demonstrated significant resolution of tumors after external radiotherapy and chemotherapy. I-131 MIBG imaging is a simple, safe, and specific method of determining the location of tumors and also is clinically useful in the evaluation and management of patients with neuroblastoma.

3-Iodobenzylguanidine↗

Extensive destruction of the eyeball by invasion of basal cell carcinoma of the eyelid.

BACKGROUND: Eyeball destruction caused by invasion of basal cell carcinoma of the eyelid. CASE: A 100-year-old woman showed extensive eyeball destruction caused by the invasion of basal cell carcinoma of the eyelid. Complete ophthalmologic examinations, including computed tomographic (CT) scans of the orbit, were performed. The patient underwent incisional biopsy and bacteriological examination of the exudate from the lesion. OBSERVATIONS: Orbital CT scan showed a mass in the extraconal space of the right orbit, with extension to the adjacent sinus cavity without brain involvement. The remnant of the eyeball was posteriorly displaced. Pseudomonas aeruginosa was identified by culture examination of the exudate. Histological study of the biopsy specimen showed basal cell carcinoma of the noduloulcerative type. CONCLUSIONS: Basal cell carcinoma of the eyelid had caused severe periorbital and eyeball destruction.

Aged↗

Histopathological study of frontalis suspension materials.

PURPOSE: This study is designed to find the most suitable frontalis suspension material by comparing the histopathologic findings of frequently used suspension materials in vivo. METHODS: Three kinds of suspension materials-autologous fascia lata, 1-0 Prolene suture material, and Silicone Band-were implanted in the white rabbit. Histopathologic study was done sequentially 1 week, 2 weeks, 4 weeks, and 8 weeks after implantation. RESULTS: Histologically, autologous fascia lata showed less inflammatory reaction and better incorporation with surrounding structures than the Silicone Band and suture material. Suture material and Silicone Band showed marked inflammatory reaction and did not incorporate or tightly bond with surrounding tissue in any of the samples. CONCLUSIONS: Fresh autologous fascia lata appears to be the most suitable material for frontalis suspension after histopathological testing.

Animals↗