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Biomedical subjects

H Moon

Publications and source records attributed to H Moon.

At least 37 records · Page 2Linked to original sources
PubMed1998

National survey of Korean dentists' knowledge and opinions: dental caries etiology and prevention.

OBJECTIVE: Dentists have the potential to influence what their patients know and do regarding dental caries prevention. The practices of dentists and what they tell their patients are influenced, in part, by their own knowledge and opinions. The purposes of this study were to determine the level of knowledge and opinions about caries etiology and prevention among Korean dentists and to describe related factors. METHODS: A pretested, 27-item questionnaire was mailed to 2,047 dentists, selected by a stratified random sampling allocated proportionately. A postcard reminder was sent to all dentists after one week. Nonrespondents were sent additional complete mailings after three, seven, and nine weeks. The response rate was 83 percent (n = 1,700 dentists). RESULTS: Analysis of six factors thought to be related to knowledge about caries etiology and prevention showed that recent graduates and dentists who worked in public health centers were likely to be more knowledgeable about caries etiology and prevention than their counterparts (P < .05). In regression analysis of perceived effectiveness of caries-preventive procedures for children, recent graduates, males, and dentists who worked in public health centers tended to rate caries-preventive procedures more effective than other dentists (P < .05). Dentists who had experience with school-based preventive programs and dentists in rural areas were likely to rate caries-preventive procedures for adults more effective than other dentists (P < .05). CONCLUSIONS: Overall, results of this study suggest that the majority of dentists do not know current information concerning etiology and prevention of dental caries, mechanisms of action of fluoride, and effectiveness of preventive procedures for children and adults. Efforts to enhance the level of knowledge and practices of Korean dentists about caries prevention should focus on strategies to educate older graduates and female dentists, especially those in private practice.

Adult↗
PubMed1998

Psoriasiform eruption triggered by recombinant granulocyte-macrophage colony stimulating factor (rGM-CSF) and exacerbated by granulocyte colony stimulating factor (rG-CSF) in a patient with breast cancer.

Colony-stimulating factors (CSFs) are commonly used for the treatment of neutropenia following chemotherapy and for the mobilization of peripheral blood stem cells (PBSC). We recently experienced a rare case of a new onset of psoriasiform eruption by GM-CSF (granulocyte-macrophage colony-stimulating factor) which was exacerbated by G-CSF (granulocyte colony-stimulating factor) in a patient with breast cancer. A 36-year-old woman had received neoadjuvant chemotherapy (cyclophosphamide, epirubicin and 5-fluorouracil), modified radical mastectomy and adjuvant chemotherapy with paclitaxel and mitoxantrone followed by GM-CSF administration for the treatment of locally advanced breast cancer. She had developed a psoriatic skin lesion on face and both upper arms during leukocyte recovery in spite of no previous history of psoriasis. Next, the chemotherapy course was complicated by a flare of mild psoriatic skin lesion, although CSF was changed into G-CSF due to GM-CSF-associated psoriasis. Subsequently, she had had high-dose chemotherapy and autologous peripheral blood stem cell transplantation for consolidation therapy. GM-CSF was administered for the mobilization of PBSC and post-transplant period, but psoriatic skin lesion did not appear. During 6 months after PBSCT, psoriasiform eruption did not appear.

Adult↗
PubMed1997

Investigation of filter sets for supervised pixel classification of cephalometric landmarks by spatial spectroscopy.

The diagnostic process of orthodontics requires the analysis of a cephalometric radiograph. Image landmarks on this two-dimensional lateral projection image of the patient's head are manually identified and spatial relationships are evaluated. This method is very time consuming. A reliable method for automatic computer landmark identification does not exist. Spatial Spectroscopy is a proposed method of automatic landmark identification on cephalometric radiographs, that decomposes an image by convolving it with a set of filters followed by a statistical decision process. The purpose of this paper is to discuss and test appropriate filter sets for the application of Spatial Spectroscopy for automatic identification of cephalometric radiographic landmarks. This study evaluated two different filter sets with 15 landmarks on fourteen images. Spatial Spectroscopy was able to consistently locate landmarks on all 14 cephalometric radiographs tested. The mean landmark identification error of 0.841 +/- 1.253 pixels for a Multiscale Derivative filter set and 0.912 +/- 1.364 pixels for an Offset Gaussian filter set was not significantly different. Furthermore, there were no significant differences between identification of individual landmarks for the Multiscale Derivative and the Offset Gaussian filter set (P > 0.05). These results suggest that Spatial Spectroscopy may be useful in landmark identification tasks.

Cephalometry↗
PubMed1996

Barrett's esophagus: metaplastic cells with loss of heterozygosity at the APC gene locus are clonal precursors to invasive adenocarcinoma.

Adenocarcinoma in Barrett's esophagus is the second most rapidly increasing cancer in western society. The cause and pathogenesis are unknown. Although histological studies suggest that there is successive progression from metaplasia and dysplasia, with a high risk of subsequent invasive carcinoma, at present there is no direct evidence that metaplastic and dysplastic epithelia are clonal precursors of adenocarcinoma. We selected 12 esophagectomy specimens of Barrett's esophagus patients, which showed a spectrum of normal tissue, metaplasia, dysplasia, and invasive carcinoma in each individual biopsy. We applied the microdissection technique to selectively procure microscopic tissue samples from H&E-stained slides for genetic evaluation using polymorphic markers flanking the APC gene locus. Identical APC gene alterations were found in the dysplastic and adenocarcinoma foci of all informative cases. The same changes were observed even in some metaplastic foci adjacent to dysplasia. Furthermore, clonality analysis of X-chromosome inactivation in female cases verified the same X-chromosome inactivation pattern in carcinoma, dysplasia, and metaplasia adjacent to dysplasia. No APC gene alterations were found in the normal epithelium and metaplasia distant from dysplasia. These data show for the first time that a tissue field of genotypic changes precedes the histopathological phenotypic changes of carcinoma in Barrett's esophagus syndrome. Our findings, in conjunction with the applied tissue microdissection technique, may help identify genotypic changes in patients with Barrett's esophagus before phenotypic changes occur. Therefore, genotyping of Barrett's metaplastic epithelium may supplement the histopathological evaluation of Barrett's esophagus.

Adenocarcinoma↗
PubMed1995

X-gene product antagonizes the p53-mediated inhibition of hepatitis B virus replication through regulation of the pregenomic/core promoter.

Employing the glutathione S-transferase column retention method and far Western analysis, we found a physical association between tumor suppressor p53 and the hepatitis B virus X-gene product, which led us to study the function of observed interaction in relation to viral propagation. In the cell culture-based in vitro replication system, expression of p53 resulted in dramatic inhibition of viral replication, and this inhibition was relieved by the coexpression of the X-gene product in a dose-dependent manner. Furthermore, the activity of pregenomic/core promoter, responsible for the synthesis of pregenomic RNA, was almost completely inhibited upon expression of p53, and as in the replication assay, the inhibition was rescued by the coexpression of the X-gene product in a dose-dependent manner. Based on these results, we propose that the ratio of X-gene product to p53 is an important factor determining the fate of viral replication through modulation of the pregenomic/core promoter.

Base Sequence↗
PubMed1995

Fluorescence analysis of the interaction between ganglioside GM1-containing phospholipid vesicles and the B subunit of cholera toxin.

Binding of cholera toxin B protomer (CT-B) to a pyrene-labeled analogue of its ganglioside GM1 receptor (pyrene-GM1) in the absence and presence of phosphatidylcholine vesicles was monitored using steady-state fluorescence spectroscopy. CT-B association with pyrene-GM1 micelles induces changes in the fluorescence properties of this ganglioside analogue that are consistent with its conversion from an excimer to a monomer form. Incubation of pyrene-GM1 with preformed vesicles of phosphatidylcholine (PC) results in complete conversion of pyrene-GM1 to its monomer form, however, unlike with CT-B binding, incorporation of pyrene-GM1 into PC vesicles occurs with a concomitant loss of fluorescence quenching by the small polar quenching agent acrylamide. Subsequent binding of CT-B to the PC-GM1 composite vesicles causes no further change in the pyrene fluorescence emission spectrum but does appear to increase acrylamide accessibility. These data lead to the conclusion that cholera toxin binding to a cell membrane alters membrane packing at the site of attachment. Furthermore, this phenomenon appears to be influenced by environmental conditions such as pH. A pH of about 4.0 or less causes acrylamide quenching to decrease to approximately the levels observed in the absence of CT-B. These results may be useful in describing the dynamics of the interaction between cholera toxin and target cell membranes. Moreover, these data could provide clues to the mechanism by which the toxic portion of CT is able to enter the cytoplasm of target cells.

Acrylamide↗
PubMed1992

Stimulation of anchorage-independent cell growth by endothelin in NRK 49F cells.

Endothelin (ET) is a vasoconstrictor peptide originally isolated from vascular endothelial cells. Recent studies have revealed that ET has many biological functions including growth factor-like activity. The present study aims to clarify whether ET-1 possesses the ability to stimulate anchorage-independent cellular growth, an indicator of factors with transforming activity. We found that NRK 49F cells possess a large number of high-affinity ET-1 receptors; labeled 125I-ET-1 binding was displaced by unlabeled ET-2 in a similar dose response, but in the case of ET-3, 100-fold more was required. Specific 125I-ET-3 binding was undetectable in NRK 49F cells, indicating that ET receptors in NRK 49F cells are ET-1/ET-2 selective. NRK 49F is a cell line which is most commonly used to assay for anchorage-independent cellular growth. Therefore, we explored whether ETs promote anchorage-independent cellular growth in this cell line. ET-1 and ET-2 stimulated NRK colony formation dose dependently in the presence of 1 nM epidermal growth factor (EGF). In contrast, ET-3 did not have colony-stimulating ability. In the presence of EGF, the maximal effect of ET-1 was approximately 90% of that of transforming growth factor-beta. Moreover, in the presence of maximal stimulating concentrations of EGF and transforming growth factor-beta, ET-1 additionally induced colony formation. These results indicate that ET-1 and -2 possess transforming growth factor-like activity for NRK 49F cells. Since ET-1 and -2 increased intracellular calcium levels, this ion may participate in signal transduction pathways by which ET-1 and -2 promote colony formation.

Animals↗
PubMed1992

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↗
PubMed1991

Reduced spinal bone mass in patients with uterine cervical cancer.

Bone destruction and hypercalcemia are well-recognized complications in a variety of neoplasms without bone metastasis. Reduction in the volume of trabecular bone has been confirmed by histomorphometric study, but not by bone densitometer. We measured spinal bone mineral densities by dual-photon absorptiometry in 85 patients with invasive uterine cervical cancer and compared them with measurements from 148 control women. When adjusted for age and menopause duration, mean bone mineral density in patients with uterine cervical cancer was 12.8% lower (P = .0003) and age-matched percentiles were 9.1% lower (P = .0003) than in control women. The deficits in bone mineral density and age-matched percentiles were confined to the uterine cervical cancer patients in their fifties, ie, less than 5 years' menopause duration. Serum concentrations of calcium, phosphate, creatinine, and alkaline phosphatase were not different between control women and the patients with uterine cervical cancer. The results suggest that women with uterine cervical cancer have an increased risk of developing osteoporosis.

Adult↗
PubMed1990

Histologic disappearance of locally advanced vaginal cancer after combination chemotherapy.

Clinically and histologically complete disappearance of local tumor and pelvic sidewall involvement was achieved in a patient with primary advanced squamous cell carcinoma of the vagina administered combination chemotherapy prior to operation. Radical hysterectomy, total vaginectomy, bilateral salpingo-oophorectomy, bilateral pelvic lymphadenectomy, and paraaortic lymph node biopsy were performed after seven courses of combination chemotherapy with vinblastine, bleomycin, and cis-platinum. This encouraging result warrants further investigation of combination chemotherapy in other patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

Two-year survival: preoperative adjuvant chemotherapy in the treatment of cervical cancer stages Ib and II with bulky tumor.

The effect of preoperative adjuvant chemotherapy on the 2-year survival rate of patients with locally advanced cervical cancer (stages Ib and II with bulky tumour) was evaluated. The 54 patients first received initial chemotherapy of vinblastine, bleomycin, and cis-platinum in a combined regimen (VBP) and then radical hysterectomy. The overall histologic response rate to chemotherapy of the primary tumor confirmed in the surgical specimen was 81% including microscopic or no evidence of disease (41%, Grade III or IV). A lower than expected incidence of lymph node metastasis (20%) was found. All nodal metastasis was noted in patients with Grades I or II (P = 0.0034). Median follow-up was 36 months (range 26-60 months). Three recurrences (6%) appeared and those patients died of the disease within 24 months. Thus the 2-year tumour-free survival rate was 94%. The patients who had positive nodes more often experienced recurrence (27 vs 0%) and a lower 2-year survival rate (72 vs 100%) (P = 0.0067). All of these recurrences were found in patients with three or more positive nodes. This preliminary study suggest that preoperative adjuvant chemotherapy (VBP) is effective (1) in reducing tumour volume or the stage of the disease, (2) in curing the lymph node involvement, and (3) in improving the 2-year tumour-free survival rate. A prospective randomized study comparing radical surgery alone with preoperative adjuvant chemotherapy followed by radical surgery is in progress.

Adult↗
PubMed1988

Preoperative adjuvant chemotherapy in the treatment of cervical cancer stage Ib, IIa, and IIb with bulky tumor.

Thirty-five previously untreated patients with stage Ib, IIa, and IIb squamous cell carcinoma of uterine cervix with bulky mass (more than 4 cm) were treated with initial chemotherapy of vinblastine, bleomycin, and cis-platinum combined regimen (VBP, one to five courses) and subsequent radical surgery. The effectiveness of the preoperative chemotherapy was evaluated in the surgical specimen. The overall clinical response rate was 89% and included a complete response in 16 (46%) and a partial response in 15 patients (43%). There were no differences in the response rate by age, stage, or the geographic contour of the tumor. The number of chemotherapeutic courses correlated well with the response of the primary tumor (P = 0.0004) up to three courses. Histologic examination of the resected primary tumor revealed no evidence of disease (Grade IV) in 44% of complete responders, microscopic foci (Grade III) in 38% (6), and macroscopic disease (Grade II) in 18% (3). Of 15 patients with stage IIb, 11 (73%) had a stage-down. Lymphnode metastases after chemotherapy were found in 26% (9/35) of the patients. All nodal metastases were found among the patients who had a partial response or a stable disease, and none was found in those with a complete response (P = 0.0029). This preliminary study suggests that initial chemotherapy before surgery is effective in reducing tumor volume or stage of the disease providing better circumstances for surgery, offers selection of high-risk groups of patients requiring additional chemotherapy, and might be able to eliminate effectively diseases in lymphnodes and possibly micrometastases. This regimen is now being evaluated to test its impact on survival.

Adult↗
PubMed1986

Effects of prophylactic chemotherapy for persistent trophoblastic disease in patients with complete hydatidiform mole.

Seventy-one patients with complete hydatidiform mole were prospectively randomized into two groups: one group (39 patients) was treated with a single course of methotrexate and citrovorum factor rescue as chemoprophylaxis; the other group (32 patients) was not treated. After molar evacuation, four patients from the treated group (10.3%) and ten patients from the untreated group (31.3%) developed persistent trophoblastic disease. The time interval from evacuation of the mole to diagnosis of persistent trophoblastic disease was longer in the treated group than in the untreated group (9.5 +/- 2.4 weeks versus 5.1 +/- 1.6 weeks, P less than .05). Among high-risk patients, there was a lower incidence of persistent trophoblastic disease in the treated group than in the untreated group (14.3 versus 47.4%, P less than .05). Among low-risk patients there was no difference between the groups (5.6 versus 7.7%, P greater than .05). All 14 patients with persistent trophoblastic disease achieved complete remission with therapeutic chemotherapy. More courses of chemotherapy were required until complete remission in the treated group than in the untreated group (2.5 +/- 0.5 versus 1.4 +/- 0.5, P less than .005). These findings suggest that even though chemoprophylaxis reduces the incidence of persistent trophoblastic disease in patients at high risk, it increases tumor resistance and morbidity. Although prophylactic chemotherapy with methotrexate and citrovorum factor rescue may be helpful for high-risk patients who cannot be followed or whose compliance is in question, careful follow-up remains the most important way to identify patients who should receive chemotherapy.

Adult↗
PubMed1985

Primary chemotherapy and postoperative adjuvant chemotherapy in the treatment of squamous cell carcinoma of the uterine cervix.

Two cases with squamous cell carcinoma of the cervix stage IIB with primary tumor mass about 2 X 2 X 2 cm were treated with primary chemotherapy of cis-platinum, 20 micrograms/m2 body surface intravenously daily for 5 consecutive days. Papanicolaou smear turned negative after two courses of chemotherapy in both cases. One of those was followed by radical hysterectomy with lymphadenectomy which confirmed that there was no evidence of disease by histopathology. The third case with stage IIIB and bulky tumor with involvement of pelvic and left common iliac lymph nodes was treated with simple hysterectomy followed by adjuvant chemotherapy with the same medication described above. Complete responses were obtained in all three cases and they are now doing well in a tumor-free state for 26, 30, and 28 months, respectively.

Carcinoma, Squamous Cell↗