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Biomedical subjects

J S Cho

Publications and source records attributed to J S Cho.

At least 55 records · Page 3Linked to original sources
PubMed1994

Preoperative assessment of gastric carcinoma: value of two-phase dynamic CT with mechanical iv. injection of contrast material.

OBJECTIVE: The purpose of this study was to evaluate the utility of two-phase dynamic CT performed with mechanical IV injection of a bolus of contrast medium after oral intake of water in the preoperative staging of gastric cancers. SUBJECTS AND METHODS: We performed incremental dynamic CT in 52 patients with pathologically proved gastric cancers. Dynamic CT findings were prospectively analyzed and correlated with surgical and histopathologic findings. A total of 150 ml of nonionic contrast medium was administered IV with a power injector at a flow rate of 5 ml/sec for 30 sec, and two-phase images were obtained at 30 sec (early phase) and 2 min (equilibrium phase) after the start of bolus injection. RESULTS: Forty-one advanced gastric carcinomas showed a moderate to marked degree of heterogeneous enhancement in the early phase and homogeneous enhancement of the entire lesion in the equilibrium phase of dynamic CT. The primary tumors were correctly detected with dynamic CT in five (56%) of the nine early gastric cancers and in 41 (95%) of the 43 advanced gastric cancers. The overall detection rate of gastric cancers was 88% (46 of 52 cases). The accuracies of dynamic CT according to TNM staging in determining the depth of tumor invasion, the degree of serosal invasion, and regional lymph node metastasis were 65% (34 of 52 cases), 83% (38 of 46 cases), and 70% (32 of 46 cases), respectively. CONCLUSION: Our findings show that two-phase incremental dynamic CT with mechanical IV injection of a bolus of contrast medium after oral intake of water improves the diagnostic accuracy of CT over that provided by conventional CT in the preoperative staging of gastric cancers.

Adult↗
PubMed1994

The utilization of Doppler ultrasonography with color flow mapping in the diagnosis and evaluation of malignant trophoblastic tumors.

The Doppler ultrasound with color flow mapping image has been recently applied for the evaluation of gynecologic diseases, in particular, malignant trophoblastic tumors with the characteristic abundant blood flow. Doppler color flow mapping of uterine artery and intratumoral blood vessels was performed at a regular interval in all 26 patients including 3 cases of lost for follow up. Systolic/diastolic (S/D) ratio representing blood flow was measured in 19 cases of malignant trophoblastic tumors and 7 cases of hydatidiform mole diagnosed at the department of Obstetrics and Gynecology, Yonsei University, College of Medicine. The initial mean S/D ratio and standard deviation(SD) of uterine artery in 11 remitted and 5 non-remitted patients were 2.72 +/- 1.31 and 2.69 +/- 1.80, respectively. No significant difference was noted between two groups. However, the final S/D ratio of uterine artery in remitted group showed significantly higher values than non-remitted group, of which values were 6.23 +/- 2.38 and 3.08 +/- 1.54, respectively (P < 0.05). In aspect of blood flow changes in malignant trophoblastic tumors after chemotherapy, remitted group showed entirely disappeared blood flow, while non-remitted group had persistent blood flow. The mean S/D ratio and SD measured in hydatidiform mole patients were 5.43 +/- 1.65, of which value reflects higher resistance than malignant trophoblastic tumors. Also blood flow was not detected in all cases. This study suggests that color flow mapping Doppler ultrasound can be a useful method in diagnosing and monitoring the treatment in malignant trophoblastic tumors along with the conventional serum beta-hCG titration.

Adult↗
PubMed1992

Antibodies against a 30 kilodalton cochlear protein and type II and IX collagens in the serum of patients with inner ear diseases.

Collagen molecules are major extracellular matrix proteins involved in the development and support of delicate auditory sensory organs. Type II collagen is widely distributed within inner ear tissues, while type IX is found only within the labyrinthine membrane and dense fibers of the tectorial membrane. Antibody specific for type II collagen has been shown to be elevated in some patients with hearing loss due to several presumably autoimmune illnesses (including Meniere's disease, otosclerosis, chronic progressive sensorineural hearing loss, and relapsing polychondritis). Purified human type II and IX collagens and an extract of human cochlear tissue were subjected to isolation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and transferred to nitrocellulose. The sera of 21 patients with inner ear disease were examined for the presence of anticollagen and anticochlear antibodies; the sera were used to probe Western blots of purified human collagens II, IX, and XI, and cochlear protein extract with peroxidase-conjugated goat anti human polyvalent immunoglobulin as the second antibody. Anti-type II collagen antibodies were seen in 12 of 21 (57%) patients, while 13 of 21 (62%) had anti-type IX antibodies detectable by Western blot. A previously unreported 30 kd (probably noncollagen) protein was 21 (62%) had anti-type IX antibodies detectable by Western blot. A previously unreported 30 kd (probably noncollagen) protein was found by SDS-PAGE of human cochlear tissue extracts, with 3 patients, all with Meniere's disease, having antibody activity to this protein detected by Western blot.(ABSTRACT TRUNCATED AT 250 WORDS)

Blotting, Western↗
PubMed1991

Growth of vascularized composite mandibular allografts in young rabbits.

Forty-one hemimandible allografts were transplanted in young rabbits immunosuppressed with cyclosporine. The majority of the grafts demonstrated normal wound healing, and growth of hair, bone, and teeth. The mandibular body and the premolars showed significant growth in length. The allografted mandibles functioned sufficiently that the rabbits took oral nourishment soon after surgery. Long-term survival was limited by a toxic "wasting syndrome" specific for rabbits under treatment with cyclosporine.

Animals↗
PubMed1991

Synergistic effect of irradiation and hyperthermia on established cell lines derived from maxillary carcinoma. Report I.

Cultured tumor cells of an established cell line derived from cancer of the head and neck (maxillary and lingual cancer) were irradiated with X-rays (5 or 10 Gy). This treatment inhibited cell proliferation in a dose-dependent way. Cell cycle analysis showed that the ratio of cells in the S phase to the population of viable cells was higher than that in a non-irradiated control group. Thus, the S phase was prolonged by exposure to X-rays. Cell proliferation was also inhibited by 1 h of heat treatment at 43 degrees C. However, movement through the cell cycle was slowed down overall and no cell aggregation in any phase of the cell cycle was found. Proliferation of not only radioresistant but also radiosensitive cells was inhibited by this treatment. Hyperthermia at 43 degrees C for 1 h did not affect cell proliferation, nor did it influence the pattern of cell cycle distribution. However, it caused a decrease in intracellular polyamine amount. The combination of irradiation and hyperthermia caused a stronger inhibition than either treatment alone. The synergistic effect of the two treatments probably arose from the S-phase cells being heat-labile although radioresistant.

Cell Division↗
PubMed1986

Epithelial linings of the human semicircular canal. A scanning and transmission electron microscopic study.

We have used scanning and transmission electron microscopy to examine adult human semicircular canals taken at autopsy and an operation. Our findings can be summarized as follows. In the semicircular circular canals obtained at autopsy from a 30-year-old male, non-sensory ciliated cells having 50-60 cilia were seen sporadically in the canal side of the ampulla of the horizontal canal. A labyrinthine specimen taken at operation demonstrated folding of the cell membrane at the base of columnar cells lining the wall of that part of the canal close to the ampulla. Distal to this site, canal wall cells became progressively flattened and their intracytoplasmic organelles were seen to be progressively less abundant. These cells were found to be layered, facing the endolymphatic space. Dense filaments and fibrocytes were present outside these cells, between which were interposed single-layered basement membranes. Since the capillary network present was found to be sparse, we believe that the portion of the canal studied does not produce endolymph but plays a role in the maintenance of the composition of endolymph and perilymph.

Adult↗
PubMed1986

Enhanced production of gamma-interferon by therapy with parenteral OK-432 and alpha-interferon in patients with head and neck cancer.

Although the drug OK-432 can induce the release of gamma-interferon (IFN-gamma), the serum concentrations of IFN-gamma produced are very low. We studied the effects of combining OK-432 with alpha-interferon (IFN-alpha) on the endogenous production of IFN and the postoperative courses of patients with oral cavity cancers. Forty patients operated on for head and neck cancers were studied. Each patient was given an injection of OK-432 1 week after surgery. Between 10 and 14 days later, a combination of OK-432 and IFN-alpha was given to assess the effects of the concomitant use of IFN-alpha on IFN production. In 18 of the 30 patients given a large dose of IFN-alpha (3 or 5 X 10(6) IU/mg protein), IFN production induced by OK-432 was enhanced. A small dose of IFN-alpha (7 X 10(3) IU) did not enhance the action of OK-432. OK-432 also induced the release of both endogenous IFN-gamma and IFN-alpha, and the production of both types of IFN was enhanced by the concomitant administration of parenteral IFN-alpha. Next, 50 patients operated on for oral cavity cancers were given OK-432 or a combination of OK-432 and IFN-alpha for 4 months, and their postoperative courses were followed for 2-5 years. The clinical courses were better in the combined therapy group than in the group given OK-432 alone.

Biological Products↗
PubMed1985

Location of intravenously injected kanamycin sulfate in the middle ear mucosa.

Twelve guinea pigs were treated with intravenous kanamycin sulfate (KM) and sacrificed 2, 5, 10, and 30 min later to investigate its location in the middle ear mucosa, especially in the Eustachian tube (ET). Immunological examinations evidenced KM in the epithelial and subepithelial layers of the ET on each occasion of observation. But, it was never recognized in the tubal gland. These observations might indicate that clinically used drugs easily get to the ET except for the tubal gland which might have some barrier mechanism against foreign bodies.

Animals↗
PubMed1984

Immunological and biochemical properties of tonsillar lymphocytes.

No significant differences were found between hyperplastic tonsillitis and recurrent tonsillitis in the intensity of cell-mediated immune response of tonsillar T cells, the ratio of T cell subsets, the ratio of Tac-positive cells, and the stimulation index determined after incubation in the presence of TCGF alone. However, the proportion of the cells in phase S+G2+M, the ratio of OKT9-positive cells to total tonsillar lymphocytes, and the amount of polyamines (especially putrescine) were greater in hypertrophied tonsils than in the tonsils with recurrent tonsillitis. Some characteristics of recurrent tonsillitis are discussed from these differences. Comparison of tonsillar lymphocytes from children vs. adults produced similar results. The proportion of cells in phase S+G2+M, the ratio of OKT9, and the amount of polyamines were greater in tonsils of children. In addition, differences in the function of tonsillar and peripheral lymphocytes from the patient are also discussed.

Adolescent↗
PubMed1978

Alteration of the physicochemical properties of triphosphoinositide by nicotinic ligands.

The concentrations of nicotinic drugs required to effect a 50% transfer of triphosphol[3H]isositide from an aqueous phase to a nonaqueous phase closely approximated their concentrations for both in vivo neuromuscular blocking activity and binding to purified nicotinic receptors, and correlated well (correlation coefficient = 0.95)) with their biological activities measured by other workers in an Electrophorus electroplax preparation. The triphospho[3H]inositide transfer induced by nicotinic ligands was dependent on the lipid concentration and was potentiated by Ca2+. The affinity constants of 45Ca2+ for triphosphoinositide were similar to those for the purified nicotinic receptor. These and other findings suggest the possibility that triphosphoinositide (phosphatidylinositol bisphosphate) is a binding site of the nicotinic receptor.

Binding Sites↗