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Biomedical subjects

J K Choe

Publications and source records attributed to J K Choe.

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

Pregnancy rates in donors versus recipients according to the serum progesterone level at the time of human chorionic gonadotropin in a shared oocyte program.

Previous data suggested a subtle increase in serum P at the time of hCG injection without LH surge reduces the PR of women having oocyte retrievals for IVF; this study compared PRs of recipients in a shared oocyte program according to the donors' pre-hCG P level. There was no difference in viable PRs between recipients and donors when P < or = 1 ng/mL. The PR was similar for recipients when donors' P was > 1 ng/mL (12.7%). Donors with P > 1 ng/mL had the lowest PR: 7.2%. The data suggest that the adverse effect of higher serum P without LH surge may be on the endometrium rather than the oocyte.

Chorionic Gonadotropin↗
PubMed1994

Effect of glucocorticoids on collagen accumulation in pulmonary vascular remodeling in the rat.

Administration of corticosteroids may attenuate the development of pulmonary hypertension by inhibiting the cell proliferation and protein synthesis that occur in early pulmonary vascular remodeling. However, in vitro studies show that corticosteroids stimulate collagen synthesis in vascular smooth muscle cells, and corticosteroid administration may be deleterious in stimulating collagen deposition. To test whether corticosteroid treatment promotes vascular collagen production in vivo, we administered triamcinolone diacetate to rats exposed to 10% O2 for 3 days and measured pro alpha 1(I) collagen mRNA and the hydroxyproline/protein ratio in the main pulmonary artery. Triamcinolone treatment (12 mg/kg intraperitoneally, once daily for 3 days) reduced mean right ventricular pressure (11 +/- 1 versus 14 +/- 1 mm Hg) and protein content of pulmonary arteries (1.8 +/- 0.1 versus 2.7 +/- 0.1 mg/vessel) (both p < 0.05). However, corticosteroid treatment produced a dose-related increase in pro alpha 1(I) mRNA levels and increased the ratio of hydroxyproline/protein (47 +/- 2 versus 38 +/- 3 micrograms/mg; p < 0.05). Thus, corticosteroid administration ameliorated the increase in pulmonary hypertension in early hypoxia, but increased the proportion of collagen in the vessel wall. Corticosteroid treatment in pulmonary vascular remodeling may be deleterious in increasing the concentration of collagen in the vessel wall.

Analysis of Variance↗
PubMed1994

Liposome encapsulation improves the effect of antifibrotic agent in rat lung fibrosis.

We studied whether the therapeutic efficacy of the antifibrotic agent cis-4-hydroxy-L-proline (cHyp) in preventing bleomycin-induced pulmonary fibrosis in rats is enhanced by intratracheal delivery in liposomes. Dual-radiolabeled liposomes were used to study the distribution and stability of liposomes after intratracheal instillation. Lung retention was > 20% 1 wk after intratracheal instillation of 9 mumol phospholipid, and liposomes were intact as indicated by the ratio of the lipid and aqueous-phase markers remaining unchanged. For the fibrosis study, groups of rats were instilled with 1.2 U bleomycin (Bleo) and treated 1 and 2 wk later by single intratracheal instillation of test compounds. The control group received 0.3 ml saline (Bleo/sal). The treated groups received 9 mumol phospholipid in 0.3 ml of the following liposome preparations: empty liposomes (Bleo/lip), liposomes and 100 mg/kg of free unencapsulated cHyp (Bleo/lip/cHyp), and 100 mg/kg of liposome-encapsulated cHyp (Bleo/lip-cHyp). At 3 wk, fibrosis (mg hydroxyproline/g weight lung) by groups was as follows: control, 2.6 +/- 0.1 (SEM); Bleo/sal, 3.2 +/- 0.1, Bleo/lip, 3.2 +/- 0.1, and Bleo/lip/cHyp, 3.1 +/- 0.1, p < 0.05 compared with control; Bleo/lip-cHyp, 2.6 +/- 0.1, p < 0.05 compared with Bleo/sal, n = 3 to 6. Histologic grading of fibrosis did not show decreased fibrosis in the Bleo/lip-cHyp group, probably because of the focal nature of the fibrotic lesions. We conclude that cHyp encapsulated in liposomes prevents bleomycin-induced fibrosis by biochemical measurements. Delivery of antifibrotic agents to the lung in carrier vehicles promotes retention and may enhance their efficacy in treating bleomycin-induced pulmonary fibrosis.

Animals↗
PubMed1992

Hysteroscopic treatment of septate uterus with Neodymium-YAG laser.

OBJECTIVE: To determine the effectiveness of Neodymium-YAG (Nd-YAG) laser for hysteroscopic transection of the septate uterus to improve pregnancy outcome. DESIGN: Patients treated for recurrent pregnancy loss and/or infertility were evaluated for before versus after treatment pregnancy outcomes. SETTING: All patients were referred to a University Reproductive Endocrine and Infertility practice from 1986 through 1990. PATIENTS, PARTICIPANTS: Nineteen patients underwent hysteroscopic transection of uterine septa after exclusion of other factors that may cause recurrent fetal wastages and/or infertility. They were allowed to conceive 8 weeks after surgery after a postoperative hysterosalpingogram. Fourteen women attempted conception during a time span of 11 to 42 months; 3 patients declined to conceive, and 2 were lost to follow-up. INTERVENTIONS: Hysteroscopic transection of the uterine septum with a Nd-YAG laser was performed in all patients. The Nd-YAG laser delivered via a 600-microns bare fiber or an 800-microns sculpted fiber through operative hysteroscopy. MAIN OUTCOME MEASURES: To evaluate the success and complications of this new laser technique. RESULTS: (1) Thirteen patients conceived; 10 delivered a live infant at term; (2) 87% of the postoperative pregnancies were considered successful as compared with 11% preoperative; (3) complications included a small perforation of the uterus (no treatment needed) and development of uterine adhesions (1 case only). CONCLUSIONS: Hysteroscopic metroplasty with the Nd-YAG laser is a valuable alternative new technique for the treatment of uterine septum.

Abortion, Spontaneous↗
PubMed1992

Serum progesterone and 17-hydroxyprogesterone in the diagnosis of ectopic pregnancies and the value of progesterone replacement in intrauterine pregnancies when serum progesterone levels are low.

The corpus luteum function was evaluated in patients with surgically confirmed ectopic pregnancy (EP) in a multicenter study. In addition, the minimal threshold of serum progesterone (P) concentration required for salvaging intrauterine pregnancies (IUP) was also examined. Results show that single P or 17-OHP measurements are not diagnostic for EP, since mean P levels in EP were similar to those with spontaneous abortion though significantly lower than those in controls. 17-OHP levels in EP overlapped in 50% with IUP, and the mean levels were significantly lower only at 6-7 weeks. The 17-OHP levels when compared to hCG supports the view that corpus luteum defect is primary. In IUP, P levels < 8 ng/ml still were associated with viable (60%) pregnancy; thus no minimal threshold could be established.

17-alpha-Hydroxyprogesterone↗
PubMed1991

Argon laser laparoscopy for treatment of pelvic endometriosis associated with infertility and pelvic pain.

Argon laser laparoscopy was used for treatment of 46 patients with pelvic endometriosis. Infertility was the primary diagnosis in 31 patients, and pelvic pain was the primary diagnosis in 21 patients. A 600 mum laser fiber was used through the operative channel of the laparoscope, and the tip of the fiber was kept at a distance of 2-3 mm from the lesions. The power density used varied between 1604 and 1069 W/cm 2 at the tissue level. The pregnancy rate following treatment of the infertile group was 42%. Eighty-four percent of these pregnancies occurred within the first 8 months of treatment. In the group with pelvic pain, 8 patients experienced complete pain relief, and 13 patients experienced partial pain relief. Difficulties with the use of the fiber included breakage in 3 patients and melting of the fiber tip in 1 patient.

Abdominal Pain↗
PubMed1991

Fibronectin in the trabecular meshwork: immunofluorescent and immunoelectron microscopic findings.

We examined the fibronectin (FN) secretion of cultured trabecular meshwork (TM) cells in a normal human eye by indirect immunofluorescent technique using mouse anti-human FN monoclonal antibody and FITC-conjugated goat anti-mouse IgG. To localize FN on frozen sections of normal TM, which were obtained from 7 enucleated eyes owing to traumatic eyeball rupture, the same indirect immunofluorescent method was used. Immunoelectron microscopy was applied to demonstrate the distribution pattern of FN in the normal TM of 2 human eyes using an avidin-biotin-peroxidase complex method. In the tissue culture of TM, the TM cell walls and extracellular matrices showed an intense staining with antibody to FN. Indirect immunofluorescent staining of FN on frozen sections of TM showed strong positive reactions in the subendothelial region. There was no reaction in the central core of the trabecular beam. Immunoelectron microscopy revealed the reaction products to FN in the areas lining the trabecular endothelial cells.

Adolescent↗
PubMed1990

An antifibrotic agent reduces blood pressure in established pulmonary hypertension in the rat.

We have shown that administration of the antifibrotic agent cis-4-hydroxy-L-proline (cHyp) to rats at the onset of exposure to hypoxia prevents collagen accumulation in pulmonary arteries and the rise in pulmonary blood pressure. In this experiment, we tested whether cHyp is effective when administered after hypertension was already established. Rats were exposed to hypoxia (10% O2) for 21 days. Groups were hypoxic animals treated with cHyp (200 mg/kg sc twice daily) on days 10-21 (hypoxic cHyp) and saline-injected hypoxic animals (hypoxic). On day 21, we measured mean right ventricular pressure, hematocrit, collagen content of main and intrapulmonary arteries, and wall thickness of arterioles. Treatment reduced right ventricular pressure from 21 +/- 1 to 17 +/- 1 mmHg (P less than 0.05), hematocrit from 66 +/- 1 to 56 +/- 1% (P less than 0.05), hydroxyproline content of intrapulmonary arteries from 30 +/- 3 to 11 +/- 2 micrograms/vessel (P less than 0.05), and wall thickness from 27 +/- 3 to 16 +/- 2 microns (P less than 0.05). These results show that vascular collagen content is increased in established pulmonary hypertension and that cHyp treatment is effective in partially preventing the hemodynamic, structural, and biochemical changes if started after pulmonary hypertension is established. cHyp may also affect the rheological properties of blood.

Animals↗
PubMed1990

Ultrastructure and blood-iris barrier in experimental rubeosis iridis in rabbit.

Iris neovascularization was produced in rabbits by hypotony following repeated aspiration of the vitreous. The hypotony was produced after 0.3 ml of vitreous fluid was aspirated using a 25-gauge needle through the pars plana of 10 rabbits. For the histochemical study, horseradish peroxidase(HRP) was injected through the ear lobe vein. After fixation of the iris tissue, the tissue was treated with diaminobenzidine and examined with both light microscopy and transmission electron microscopy. The newly-formed vessel was abundant, particularly on the upper stroma of the iris. The new vessel formation was evident due to the proliferation of endothelial cells, which may have been derived from preexisting iris vessels. The endothelial cells of the newly-formed vessels revealed prominent villous processes into the vascular lumen, formation of the marginal flap, numerous fenestrations in the endothelial junction, and reaction product onto extravascular space by the cytochemical electron microscopy. These results suggest that hypotony in the rabbit produces the disruption of the blood-iris barrier and the balance between angiogenesis-antiangiogenesis modulation.

Animals↗
PubMed1989

Outflow of aqueous humor following cyclodialysis or ciliochoroidal detachment in rabbit.

Cyclodialysis and ciliochoroidal detachment were performed in three eyes of three rabbits and in three eyes of another three rabbits, respectively. After aspiration of the aqueous humor, 0.1 ml of 10% sodium fluorescein was injected intracamerally, and the eyeball was enucleated between 30 minutes and one hour after injection and prepared for fluorescence microscopy. Sodium fluorescein concentrations in the supraciliary space were much greater in the group with cyclodialysis or ciliochoroidal detachment than in the normal control group. These results suggest that (1) in the eye with cyclodialysis, the aqueous humor may freely gain access to the supraciliary space through the cleft between the anterior chamber and the supraciliary space and then be removed rapidly and (2) in the eye with ciliochoroidal detachment, the aqueous humor may pass through the uveoscleral outflow pathway.

Animals↗
PubMed1989

The incidence of congenital color deficiency among Koreans.

It is important to investigate the incidence of congenital color deficiency and to determine the type and degree because the color deficiency can effect as a handicap to certain occupations. The incidence of congenital color deficiency is remarkably constant among Caucasians but other races show considerable variations. We investigated the incidence of congenital color deficiency among Koreans by the use of H-R-R pseudoisochromatic plates. The present study revealed that the incidence of congenital color deficiency among Koreans was 31.5% (5.90% in men, 0.44% in women).

Color Vision Defects↗
PubMed1986

Pulsed CO2 laser versus conventional microsurgical anastomosis of the rat uterine horn.

The effect of pulsed CO2 laser treatment on tissue reaction and fertility was evaluated. The left uterine horn was cut with a pulsed CO2 laser in 16 rats. In eight other rats, the left uterine horn was cut with microscissors. The anastomosis in both groups was accomplished by microsurgical techniques. The adhesions were mostly filmy after laser treatment, as compared with thick adhesions in the conventional group. Absence of adhesions was found in 62.5% and 50% of the laser and conventional surgery group, respectively. Histologically, some degree of fibrosis in the muscularis layer of the uterine horn was seen in the conventional group, whereas proper muscle continuity was seen in the laser-treated group. The pregnancy rates were 81% and 87.5% in the laser and conventional groups, respectively.

Animals↗
PubMed1984

Salivary and plasma bound and "free" testosterone in men and women.

Paired samples of blood and saliva from 37 men and nine women throughout the menstrual cycle were measured for testosterone by radioimmunoassay and free testosterone by equilibrium dialysis. There was a highly significant correlation between plasma and salivary testosterone, with a correlation coefficient r = 0.71 (p = less than 0.001). In men, free testosterone constituted 78% of salivary testosterone but only 4% of plasma testosterone; mean +/- SE salivary testosterone was 193.7 +/- 6.7 pg/ml compared to plasma testosterone of 5,140 +/- 298.0 pg/ml. Salivary testosterone decreased significantly from a morning (0800 hours) level of 208 +/- 7.5 to an evening (1800 hours) level of 174 +/- 8.4 pg/ml (p = less than 0.001) (n = 23). Similarly, plasma testosterone was significantly higher in the morning (6,584 +/- 472 pg/ml) than in the evening (5,571 +/- 357 pg/ml) (p = less than 0.005) (n = 25). Free testosterone in saliva and plasma also showed significantly higher morning than evening levels. The coefficients of variability for hourly changes (0900 to 1800 hours) in salivary testosterone and free testosterone were 13.6% and 16.7% compared to 12.7% and 20.9% for plasma testosterone and free testosterone, respectively. In women, salivary testosterone during the proliferative phase of the menstrual cycle was 108.3 +/- 5.8 pg/ml, and it increased significantly to 130.5 +/- 6.0 pg/ml in the secretory phase (p = less than 0.02). Our findings indicate that measurements of salivary testosterone reflect plasma testosterone and may be a useful noninvasive method of assessing levels of testosterone.

Adolescent↗
PubMed1984

Epithelioid granulomas of the bone marrow in non-Hodgkin's lymphoproliferative malignancies.

Ten cases of epithelioid granulomas in the bone marrow of patients with various non-Hodgkin's lymphoproliferative malignancies have been encountered. These included six with non-Hodgkin's lymphoma (three histiocytic and three poorly differentiated lymphocytic types), three with multiple myeloma, and one with acute lymphoblastic leukemia. The bone marrow was not involved by the primary disease in two of the six patients with lymphoma, whereas three with lymphoma showed both granulomatous and lymphomatous lesions in the same marrow specimens, and in one, these lesions were seen in the marrow at different times. The three myeloma patients showed evidence of both myeloma and granulomas in their marrow. In the case of acute lymphoblastic leukemia, the bone marrow showed only granulomas, the leukemic process being in complete remission. Although small numbers of similar cases have been reported before, the authors were unable to find a previous report of acute lymphoblastic leukemia associated with bone marrow granulomas. Although the pathogenesis and the clinical significance of the granulomatous lesion of the bone marrow in non-Hodgkin's lymphoproliferative malignancies are unknown, this lesion should be differentiated from infectious or lipid granulomas as well as from involvement by the primary disease.

Adult↗
PubMed1984

Clinical and histologic evaluation of laser reanastomosis of the uterine tube.

Conventional microsurgical reanastomosis was compared with laser microsurgical reanastomosis of previously ligated uterine tubes in 14 rabbits. A final laparotomy was performed to determine adhesion formation and uterine tube patency, and a histologic examination was done of the anastomosis sites using four histologic indices for grading. Laser microsurgery produced significantly less adhesions (mean +/- standard error of the mean adhesion score, 0.79 +/- 0.24) than conventional microsurgery (2.29 +/- 0.13, P less than 0.001). However, there was no significant difference in all four histologic indices of tissue reunion at the anastomosis site between the two types of surgical technique. In a separate experiment, CO2 laser was found to be unable to weld uterine tubes successfully. Thus, the CO2 laser can significantly reduce postoperative adhesions in microsurgical uterine tube reanastomosis but without any significant histologic difference in tissue reunion, compared with conventional microsurgery.

Animals↗