Search PubMed⌕ Search

Biomedical subjects

H C Chung

Publications and source records attributed to H C Chung.

At least 73 records · Page 4Linked to original sources
PubMed1992

Point mutation at codon 12 of the c-Ha-ras gene in human gastric cancers.

The molecular mechanisms of the carcinogenic process of gastric cancer have not been fully understood yet. In order to know whether c-Ha-ras gene is being involved in the process of gastric carcinogenesis, 8 gastric cancer cell lines, 8 cases of gastric cancer and same number of adjacent dysplasia were analyzed for the presence of mutation at codon 12, 13 and 61 of the c-Ha-ras gene by using polymerase chain reaction (PCR) and mutant-specific oligonucleotide hybridization. Point mutations at codon 12 of the c-Ha-ras gene were found in 2 out of 8 gastric cancer and dysplasia samples in one case, but we found no mutation at codon 13 or 61 of the c-Ha-ras gene. These results suggest that the frequency of mutation of the c-Ha-ras gene detected by sensitive PCR technique is low indeed, however it would be notable that such a genetic change has been detected in the dysplastic lesion of the gastric cancer patient.

Base Sequence↗
PubMed1992

The value of immunohistochemical detection of P-glycoprotein in breast cancer before and after induction chemotherapy.

We have studied the patterns of P-glycoprotein expression before and after 3 cycles of induction chemotherapy (5-fluorouracil, adriamycin and cyclophosphamide) using immunohistochemically stained paraffin-embedded specimen of 28 patients with locally advanced breast cancer. The frequency of P-glycoprotein expression in untreated breast cancer turned out to be very low: only one out of 28 untreated, biopsy specimen at the time of diagnosis was positive. The frequency of P-glycoprotein expression was markedly increased from 9.1% before chemotherapy to 63.6% after induction chemotherapy (p = 0.006). After 3 cycles of induction chemotherapy, 25 patients had obtained clinical response to chemotherapy (4, CR; 21, PR). Eleven out of 25 tumors (44%) showing clinical response and all three tumors (100%) with minimal response have expressed P-glycoprotein. One out of 6 patients (16.7%) with microscopic residual tumor seen in mastectomy specimen expressed P-glycoprotein, whereas 13 of 22 patients (59.1%) with gross residual tumor showed the presence of P-glycoprotein (p = 0.08). The frequency of intrinsic P-glycoprotein expression in untreated breast cancer was quite low, but approximately half of the patients do acquire P-glycoprotein expression during the cycles of induction chemotherapy. Therefore, the results suggest that the immunohistochemical detection of P-glycoprotein on residual tumor cells after induction chemotherapy can predict acquired drug resistance in breast cancer.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1992

Should all the N3 lymph nodes group metastasis be regarded as distant metastasis (M1) in curatively resected gastric cancer?

Recently, metastasis to N3 lymph nodes group was regarded as distant metastasis by the new TNM staging system due to poor overall survival. However, the 5-year overall survival rate of patients with metastasis to N3 groups was 34.5% after curative surgery. Moreover, in patients with metastasis to lymph node subgroups of #12, #13, #14, the overall 5-year survival rate increased upto 47.2% after curative resection and adjuvant chemotherapy. This was similar to that of the patients with metastasis to N1 and N2 lymph nodes groups. But in these highly tumor burden states, no survival benefit was found with the addition of immunotherapy to chemotherapy as we achieved in stage II and III. Therefore, we suggest that, at least, metastasis to #12, #13, #14 lymph nodes subgroups should not be categorized as a distant metastasis. And in these situations, active curative radical surgery with extended lymphadenectomy and adjuvant chemotherapy are recommended.

Adult↗
PubMed1992

Overexpression of erbB-2 protein in gastric adenocarcinoma--a potential role in therapeutic response to adjuvant 5-FU-doxorubicin regimen.

In order to study the influence of erbB-2 protein overexpression on outcome of patients with gastric cancer after attempted curative resection with or without adjuvant chemotherapy, paraffin embedded sections from 109 cases of primary gastric cancer with defined treatments have been immunostained for erbB-2 protein in a retrospective study. Thirty four cases (31%) showed strong membrane staining of tumor cells. erbB-2 overexpression did not show significant effect on outcome when all patients were considered. However, erbB-2 overexpression was an indicator for poor disease free survival (p = 0.0474), local relapse free survival (p = 0.0293), and overall survival (p = 0.0310) of the patients treated with surgery only (N = 51), while it did not show any effect on outcome of patients treated with 5-FU plus Doxorubicin (FA) as adjuvant chemotherapy (N = 58). Furthermore, the apparent therapeutic benefit from FA regimen was restricted to patients with erbB-2 positive tumors. Combined predictive value of erbB-2 and FA regimen was found to be significant in predicting local relapse in multivariate analysis (p = 0.0439). The data suggests that erbB-2 may be associated with an improved response to FA regimen and that erbB-2 should be included as a potential confounding variable in the analysis of the data from the clinical trials for gastric cancer.

Adenocarcinoma↗
PubMed1992

Different sensory blockade of interscalene versus axillary approach of brachial plexus block.

We examined results of brachial plexus block in 31 young male patients who underwent upper extremity surgical procedures. Interscalene block was performed using a paresthesia technique in 13 patients and axillary block, using the perivascular technique, in 18 patients. In both groups, 30 ml 1.5% lidocaine with 1:200,000 epinephrine was injected. Sensory blockade was evaluated at 5 min and 15 min after injection, determined by pinprick. Results showed that the interscalene technique preferentially blocked the cephalad nerves while the axillary technique produced similar block of both cephalad and caudal nerves of the brachial plexus. Difference between groups was statistically significant, suggesting that the extent of nerve block depends on the technique of approach per se. The difference in patterns of nerve blocked by either technique could be due to the access of local anesthetic to the different components of plexus in the sheath.

Adult↗
PubMed1992

Partially endothelium-dependent relaxing effect of ketamine on the canine basilar artery in vitro.

The influence of the endothelium on the vasodilator effect of ketamine and its possible mechanism of action on intracellular calcium levels were investigated. We conducted experiments in vitro on canine basilar arteries precontracted with 5-HT and with potassium at high concentrations. Ketamine (10(-6) to 10(-3) M), added cumulatively, relaxed both 5-HT and high-K(+)-induced contraction of basilar arteries (with or without endothelium) in a dose-dependent manner. The ED50s of ketamine for relaxation of 5-HT and high-K(+)-induced contraction for intact endothelium were 3 x 10(-4) M and 6 x 10(-4) M, respectively, and for denuded preparations, 7 x 10(-4) M and 15 x 10(-4) M, respectively. Methylene blue, which blocks the release and/or the effect of endothelium derived relaxing factor, significantly attenuated the relaxation effect of ketamine on the basilar artery. Our results indicate that the endothelium may be responsible for a part of the vasodilator effect of ketamine. We also examined the effect of pretreatment of basilar artery with ketamine (5 x 10(-4) M) on intracellular calcium levels when contraction was induced by 5-HT or by high K+ concentrations. Ketamine significantly inhibited the phase of the contraction induced by high K+. Thus, the vasodilator effect of ketamine may be mediated by inhibition of calcium influx and by the release of EDRF.

Animals↗
PubMed1991

Expression of prognostic factors (EGFR, ER) by immunohistochemical staining method in male breast cancer.

Twelve male patients with operable breast cancer were evaluated for the expression of prognostic factors by immunohistochemical staining assay. Seven patients were stage I & II, and five patients were stage III. Axillary lymph node positivity was 42%. Nine patients were nuclear grade I, three were nuclear grade II, and none were nuclear grade III. The expression rate of EGFR (epidermal growth factor receptor), ER (estrogen receptor) were 8.3%, 70.0% respectively. This limited data suggest better tumor behavior in male than in female breast cancer. Adjuvant treatment should be considered in male breast cancer just as in females, based on axillary lymph node and ER states.

Breast Neoplasms↗
PubMed1991

Coexisting mycosis fungoides and Hodgkin's disease as a composite lymphoma: a case report.

Within the past few years, an increasing number of reports of Hodgkin's disease following the diagnosis of, and frequently coexisting with, mycosis fungoides have appeared. Previously, Hodgkin's disease found in the lymph nodes of the patient diagnosed as mycosis fungoides was considered as a transformed form of the mycosis fungoides. But, now it has been proven that Hodgkin's disease and mycosis fungoides are histologically and immunohistochemically distinct disease entities. We report a well-documented case of a man who developed Hodgkin's disease and mycosis fungoides simultaneously as a composite lymphoma. Our case emphasizes the importance of considering the diagnosis of another lymphoma in patients with mycosis fungoides who have lymphadenopathy. The cutaneous mycosis fungoides and the Hodgkin's disease should be treated as an independent disease.

Adult↗
PubMed1991

Experience with a controlled-release oral morphine for cancer pain management.

An open pilot study was performed to assess the analgesic efficacy and acceptability of a controlled-release oral morphine preparation. Between March 1989 and August 1990, 50 patients were treated with MS Contin (morphine sulphate tablets-MS Continus) for the pain caused by advanced cancer. The participants consisted of 28 males and 22 females ranging in age from 8 to 78 years (median 52 years). Twenty-two patients were actively receiving either cancer chemotherapy (15 patients), radiotherapy (2 patients), combined chemoradiotherapy (3 patients) or hormonal treatment (2 patients). Most of the subjects had pain caused by visceral disease and bone metastasis. A combination of causes was also present in 19 patients. The patients had a wide variety of cancers the most common being stomach cancer. In 24 patients, concomitant non-opioid or non-morphine opioid analgesics were combined with MS Contin. The median duration between cancer diagnosis and MS Contin initiation was 11.0 months. MS Contin was given on average for 1.5 months. The median survival after study enrollment was 1.8 months. Of the 50 enrolled patients, three left the study in the early phase due to drug-related adverse effects. In almost all the patients the effective dose was 60 mg/day with 45 days of response duration. The required duration for dose adjustment was nine days. The most common side effects were constipation and vomiting, which were controlled with conservative care. Two patients withdrew because of intractable vomiting and one because of mental drowsiness. In conclusion, twice-a-day moderate dose oral MS Contin therapy for cancer pain offers effective pain relief with minimal, tolerable side effects in the majority of patients in Korea.

Administration, Oral↗
PubMed1990

Locally advanced unresectable gastric cancer successfully resected after neoadjuvant chemotherapy with FADE regimen.

The prognosis of unresectable advanced gastric cancer is extremely poor. We tried a neoadjuvant chemotherapy in locally advanced unresectable stomach cancer diagnosed by initial explo-laparotomy. After chemotherapy with the FADE regimen (5-fluorouracil + adriamycin + cisplatin + etoposide), the patient was diagnosed clinically as a complete response state on re-staging with radiological gastrointestinal study, fiber-gastroscopy and computerized tomography. During the second-look operation, the advanced cancer was completely resected and the pathological diagnosis was early gastric cancer (EGC) type IIc, stage II (T1N2Mo).

Adenocarcinoma↗
PubMed1990

Comparison of adjuvant radiotherapy and chemoradiotherapy following surgery in stage IE and IIE primary gastrointestinal tract non-Hodgkin's lymphoma.

Forty patients (median age 49.6 years) were treated for primary gastrointestinal lymphoma between 1979 and 1989. There were twenty-three cases of gastric lymphoma and seventeen cases of intestinal lymphoma. Following surgery, seventeen patients received postoperative chemoradiotherapy (ACOP) by the sandwich technique, seven patients received postoperative radiotherapy, and sixteen patients did not receive any other form of adjuvant treatment. Nineteen patients were stage IE and twenty-one were stage IIE. Stage IE disease was more prevalent in the gastric lymphoma group than the intestinal lymphoma group (p less than 0.01). At a median follow-up of 17 months (1-102 + months), 17 of 19 stage IE patients and 15 of 21 stage IIE patients remained alive. The survival rate was 90% in the postoperative chemoradiotherapy group and 83.3% in the postoperative radiotherapy group at five years, and 42.7% in the surgery alone group at four years, which showed statistical significance (p less than 0.01, p less than 0.05, each). Statistically improved survival rates were achieved with a postoperative chemoradiotherapy modality in intestinal lymphoma (p less than 0.01), stage IIE (p less than 0.01), intermediate grade by NCI criteria (p less than 0.01), poorly differentiated lymphocytic lymphoma (p less than 0.05), and diffuse histiocytic lymphoma (p less than 0.01) according to Rappaport classification, compared to those of the surgically treated only group. Three local relapses occurred in the operation alone group, and one in the adjuvant radiotherapy group which occurred simultaneously with distant lymph node recurrence. The pathologic stage of all of these relapsed patients was stage IIE-2. These results suggest that adjuvant chemoradiotherapy in completely resected localized gastrointestinal non-Hodgkin's lymphoma can decrease local and systemic relapse resulting in long-term disease free survival and overall survival compared to operation alone.

Adolescent↗
PubMed1990

Male breast cancer--a 20-year review of 16 cases at Yonsei University.

Sixteen cases of male breast cancer seen over a 20-year period were reviewed. The causes of cancer of the male breast are no better understood, but major alterations in hormonal environment could be a significant factor. Some clinical characteristics correspond well with the results of other series. The median age at presentation was 61.7 years. The most frequent initial symptom was a painless mass, and the incidences of nipple discharge, central tumor location, and axillary node involvement were high. Males also had a higher incidence of local advancement which was associated with a longer delay in seeking treatment and small breast tissue. The pathologic type was infiltrating ductal type in all cases except one, and all cases showed favorable nuclear grade. Estrogen receptor analysis was performed from the tumor of 2 patients. Both of them showed a high receptor level. There was no locoregional relapse in 5 patients who received adjuvant radiotherapy in contrast to the 2 relapses in 3 patients who underwent surgery alone. And three of the five patients who received radiotherapy suffered from systemic metastasis which suggested the important role of adjuvant chemotherapy as well as radiotherapy. In light of the encouraging results about adjuvant chemotherapy in the treatment for female breast cancer with axillary lymph node involvement, it would be desirable to extend this policy to male breast cancer.

Adenocarcinoma↗
PubMed1989

Establishment and characterization of a tumor cell line from human nasopharyngeal carcinoma tissue.

An epithelial tumor cell line, CG1, was established from human nasopharyngeal carcinoma tissues. The CG1 cells are of an epithelial origin as shown by their reactivities with the epithelial-specific antikeratin antibodies and by the presence of the desmosome structure at cell-cell junctions. CG1 cells possess characteristics of tumor cells because these cells are tumorigenic in nude mice and also have reduced serum requirements for in vitro cultivation. The doubling time of CG1 cells is 20 h and these cells have been successfully cultured in vitro for more than 200 generations. The average chromosome number of these cells is 60. Slot and Southern blot hybridizations showed the presence of Epstein-Barr virus-DNA sequences in CG1 cells. This cell line provides us an in vitro system for the study of the role of Epstein-Barr virus in nasopharyngeal carcinoma.

Animals↗
PubMed1989

Oncogene expressions detected by in situ hybridization of squamous metaplasia, dysplasia and primary lung cancer in human.

In order to elucidate the dynamic changes of oncogene expression in the sequential cascade of squamous metaplasia, dysplasia, and squamous cell carcinoma of the bronchial epithelium, hybridization in situ was employed with a biotinylated oncogene probe. The expression of c-myc was localized exclusively in nuclei. While normal bronchial epithelium revealed no discernible clumps of c-myc grains, except occasional grains less than 3 per cell, squamous metaplasia showed increased number of grains and a few clusters of c-myc grains. In dysplasia, c-myc expression was more intensive than in squamous metaplasia. Approximately, 1/3 to 2/3 of tumor cell populations of squamous cell carcinomas of the lung revealed tremendously increased c-myc expression. In addition clumpy grains of c-myc in squamous cell carcinoma appeared more frequently than in squamous metaplasia or dysplasia. The c-myc expression was found to vary between different samples and within each cancer, and not all cancer cells expressed c-myc. These data indicate that c-myc oncogene plays it's role on reprogramming for growth control of cell populations particularly in multistage carcinogenesis and progression of lung cancer. These dynamic alterations of c-myc expression suggest that neoplastic transformation may occur conceivably at the dysplastic phase eventually resulting in carcinoma in situ. This means, in turn, squamous dysplasia is a putative precancerous lesion of the human lung.

Bronchial Neoplasms↗
PubMedDate not supplied

GLUT-1 expression in the cerebra of patients with Alzheimer's disease.

To investigate the molecular basis of reduced GLUT-1 concentration of the blood-brain barrier in patients with Alzheimer's disease (AD), the GLUT-1 mass, mRNA content, and structure were studied in eight patients with AD and seven age-matched controls. The results indicate that the 55-kDa GLUT-1 is significantly reduced in AD without a significant change in GLUT-1 mRNA concentrations. Because in some animal models changes in GLUT-1 expression is associated with changes in GLUT-1 mRNA structure, the length of the poly(A) tail of the GLUT-1 mRNA was estimated with a reverse transcription-polymerase chain reaction technique. The length of poly(A) tail of GLUT-1 mRNA in AD subjects was not significantly different from the controls. It is concluded that the AD-related change in GLUT-1 expression is not the result of altered poly(A) length of GLUT-1 mRNA.

Aged↗