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Biomedical subjects

Y S Chung

Publications and source records attributed to Y S Chung.

At least 19 recordsLinked to original sources
PubMed1992

Differences in expression of SPan-1 and CA15-3 antigens in blood and tissues.

Pancreatic and mammary cancer cells are reported to have different oligosaccharides on the same apomucin, the MUCI gene product. A better understanding of the tissue specificity of these sugar structures may help in identifying the source of mucins when they are found in the sera. Serum levels of 3 pancreatic-cancer-associated carbohydrate epitopes identified by monoclonal antibodies (MAbs) SPan-1, 19-9 and DU-PAN-2, were compared to those of CA15-3 in a variety of malignant conditions. CA15-3 identifies both carbohydrate and peptide determinants associated with the MUC1 apomucin in breast tissues. SPan-1 antigen was elevated in a high percentage of patients with pancreatic, gastric and colorectal cancer but in only a few of the patients with malignancies of non-GI origin such as breast, ovary and lung. The 19-9 and DU-PAN-2 antigens had a similar pattern of much greater sensitivity for pancreatic cancer than for these non-gastrointestinal cancers. The levels of these 3 markers showed significant correlations in pancreatic cancer. In contrast, CA15-3 was elevated in a large number of patients with breast, lung, ovarian and pancreatic cancers. There was no correlation of CA15-3 with the 3 other markers in pancreatic cancer. SPan-1 and DF3/115D8 antigens in blood have different mobilities in SDS-PAGE and buoyant densities. Moreover, SPan-1 and DF3 antigenic determinants are localized in different regions of the same normal and malignant pancreas and breast tissues. Thus the SPan-1 determinant can be dissociated from the breast peptide and/or carbohydrate determinants.

Antigens, Neoplasm↗
PubMed1992

Effect of choline esters on the decarbamylation of dimethylcarbamyl-acetylcholinesterase.

Acetylcholine and butyrylcholine exhibited the dose-dependent decarbamylation up to 0.2 mM, although at higher concentrations the decarbamylation degree declined. In combination with choline, butyrylcholine potentiated the choline-catalyzed decarbamylation by 30-100%, and was found to be more effective than acetylcholine in enhancing the decarbamylation. In kinetic analysis, it was observed that Ka value of choline was not remarkably altered by butyrylcholine whereas the maximum rate for decarbamylation was enhanced significantly in the presence of butyrylcholine, suggesting that butyrylcholine may affect the decarbamylation by interacting with the peripheral sites, different from the central active site which choline is known to interact with. In support of the suggestion, butyrylcholine was observed to compete with gallamine, a well known peripheral activator, and the effect of butyrylcholine was enhanced by three times at low ionic strength. In addition, acetylcholinesterase from mouse brain or bovine erythrocyte seemed to differ from electric eel enzyme in the interaction with butyrylcholine.

Acetylcholine↗
PubMed1992

Flow cytometric bromodeoxyuridine/DNA analysis of hyperthermia and/or adriamycin for human pancreatic adenocarcinoma cell line Capan-2.

The effects of hyperthermia, adriamycin (ADM), and hyperthermia combined with ADM on pancreatic cancer cells were investigated from the viewpoint of cytokinetics using flow cytometric bromodeoxyuridine (BrdUrd)/DNA analysis. Human pancreatic adenocarcinoma cell line Capan-2 was used. The untreated cells could be clearly divided into G1, S, G2M phases on contour plots of BrdUrd/DNA distribution. After heat treatment at 41-43 degrees C, there was an accumulation of cells in the G2M phase which was correlated with the increase in temperature. After heat treatment at 44 or 45 degrees C, there was marked increase in non BrdUrd-labeled cells in the S phase. ADM caused no change in the percent of non BrdUrd-labeled cells in the S phase, even after treatment with a concentration of 1.0 micrograms/ml, though that concentration of ADM caused a marked increase in the percent of cells in the G2M phase. After hyperthermia combined with ADM, the accumulation of the G2M phase increased remarkably, and was significantly higher than that after each treatment alone (P less than 0.005); however, non BrdUrd-labeled cells in the S phase did not increase. In this study the synergistic effect of hyperthermia combined with ADM in increasing the percent of cells in the G2M phase could be observed by flow cytometry. The study illustrates the importance of performing in vitro flow cytometric BrdUrd/DNA analysis of combined therapy prior to the use of the combined therapy in patients.

Adenocarcinoma↗
PubMed1992

Tumor localization and biodistribution with radiolabeled monoclonal antibody against pancreatic cancer in tumor-bearing nude mice.

Nd2 is a murine monoclonal antibody produced against a mucin fraction purified from xenografts of a human pancreatic cancer cell line SW1990. Immunoperoxidase staining showed that the antigen recognized by Nd2 was present in 82.9% of pancreatic cancer tissues but not in tissues of normal pancreas and chronic pancreatitis. However Nd2 antigen was found not to be elevated in the sera of patients with pancreatic cancer. Four days after injection of 111In-Nd2 into athymic nude mice bearing SW1990 xenograft there was a higher accumulation in the tumor compared to 111In-normal mouse IgG1. When these mice were scanned with a gamma camera, labeled Nd2 was shown to accumulate in the tumor rapidly on the 1st day after injection and by the 4th day tumor accumulation was more distinctly visualized than non-specific accumulation in liver. These results indicate that Nd2 has high specificity and reactivity for pancreatic cancer and may have possible applicants in radioimmunodetection or targeting of therapeutic drugs in pancreatic cancer.

Animals↗
PubMed1992

Thyrotropin-secreting pituitary microadenoma.

We present a 45-yr-old male with clinical signs and symptoms of mild hyperthyroidism, high serum levels of T3, T4, and FT4 as well as serum TSH concentration. The elevated alpha-subunit level and alpha-subunit/TSH molar ratio were also observed. These findings indicated the presence of hyperthyroidism due to inappropriate secretion of TSH, whose neoplastic origin was documented by nuclear magnetic resonance scan showing a 0. 6 cm pituitary adenoma. Selective pituitary adenomectomy was completely successful; alpha-subunit, TSH, T3, T 4, and FT4 normalized, and euthyroidism was restored. Light microscopic immunohistochemistry showed that the adenoma was composed of TSH-secreting cells.

Adenoma↗
PubMed1992

[Molecular size heterogeneity of SPan-1 antigen and co-expression with Lewis phenotype determinants in sera from gastrointestinal malignant diseases].

Molecular size of SPan-1 antigen and co-expression between SPan-1 epitope and Lewis phenotype determinants (LPD) on the same molecule in sera from patients with pancreatic, gastric and colon cancer and in culture medium from cancer cell line were studied. Column chromatography study on culture medium and sera showed that SPan-1 immunoreactivity was found in the void volume region as single major peak, or followed by one or two minor peak in the included volume. All of 4 pancreatic cancer cell lines showed molecular size heterogeneity. Co-expression between SPan-1 epitope and LPD on the same molecule was recognized in sera from cancer patients with Lewis a or Lewis b positive, but not in patients with Lewis a-, b-. Molecular carrying SPan-1 epitope had more frequently SPan-1 epitope than LPD in sera from cancer patients. These findings suggest that molecular size heterogeneity of SPan-1 antigen was more often in pancreatic cancer cells and overexpression of SPan-1 epitope on the same molecule seems to be specific for cancer.

Antigens, Neoplasm↗
PubMed1992

[The effect of hyperthermia against pancreatic cancer cell--various examinations including flow cytometric bromodeoxyuridine/DNA analysis].

We investigated the effect of hyperthermia against pancreatic cancer cell in various aspects including of cytokinetics. The hyperthermia above 43 degrees C was thought to have strong effect for the studies on surviving cell number and morphological change of Capan-2 and RWP-1 cells after heating treatment. The cell inoculated to the nude mice subcutaneously after heating treatment at 43 degrees C was recognized the tumor forming at 3 weeks later, however, the growth speed was slower than that of control to which untreated Capan-2 cells were inoculated. As the case of 44 degrees C, the tumor forming was not recognized at all. The cytokinetics was measured by flow cytometric bromodeoxyuridine (BrdUrd)/DNA analysis. Up to 43 degrees C in accordance with increase in the heating temperature, the accumulation in G2M phase increased, and the amount of BrdUrd incorporated 5 phase decreased. At the temperature above 44 degrees C, BrdUrd was hardly incorporated into S phase cells and the cell cycle was almost stopped. These results suggested the usefulness of hyperthermia and strong effect of heating treatment above 44 degrees C against pancreatic cancer cell.

Animals↗
PubMed1992

Early cancer of the gastric remnant--with special emphasis on the importance of follow-up of gastrectomized patients.

Seven patients with early cancer of the gastric remnant (group 1) and nine with gastric remnant cancer which developed after surgery for early gastric cancer (group 2), were studied clinicopathologically. The findings can be summarized as follows: In group 1, the majority of cases were classified as type I by gross type. Most lesions were in the posterior wall of the remnant stomach. All lesions were differentiated carcinomas. In group 2, of the nine early gastric tumors resected at the initial surgery, six were present at site A and three at site M. The gross type of the tumor was varied. Six patients underwent a Billroth II, and two a Billroth I, resection. The findings at the second operation (for gastric remnant cancer) showed that five lesions were located in the gastric stump or anastomosed region and four in the posterior or anterior wall of the remnant stomach. Histologically, the lesions included four undifferentiated and five differentiated carcinomas. Of the nine lesions involving the gastric remnant, only two were at an early stage, the remaining seven being at an advanced stage. The outcome was extremely poor in this group. Many of the patients died of carcinomatous peritonitis. In summary, a large percentage of the patients of group 1 had a type I lesion in the remnant stomach. In group 2, more than half of the lesions were located in the gastric stump or at the site of the anastomosis, and the majority of the lesions were at an advanced stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1991

The possibility of diagnosing small pancreatic cancer (less than 4.0 cm) by measuring various serum tumor markers. A retrospective study.

Comparative studies measuring various tumor markers such as SPan-1, CA 19-9, carcinoembryonic antigen (CEA), DUPAN-2, and elastase I were done in 74 patients with small pancreatic cancer including 23 cases of T1 pancreatic cancer (tumor size less than 2.0 cm) and 51 cases of T2 pancreatic cancer (tumor size between 2.1 to 4.0 cm), retrospectively. Although the mean value of these tumor markers in T1 and T2 pancreatic cancer were higher than those of the control cutoff levels, their sensitivities were different. In T1 pancreatic cancer, 13 of 23 cases (56.5%) of SPan-1 and 14 of 23 cases of (60.7%) of CA 19-9 had levels above normal. Although the numbers of patients were small, sensitivities of CEA, DUPAN-2, and elastase I were 30.8%, 22.2%, and 28.6%, respectively. In T2 pancreatic cancer, 41 of 51 cases (80.4%) of SPan-1 and 40 of 51 cases (78.4%) of CA 19-9 showed higher levels than normal, but only 46.9% of CEA, 40.0% of DUPAN-2, and 52.6% of elastase I were positive. The overall sensitivities in small pancreatic cancer (less than 4.0 cm) were 73% for SPan-1 and CA 19-9 but were less for CEA, DUPAN-2, and elastase I. These results indicate that even small pancreatic cancers release detectable pancreatic cancer-associated antigens in serum in more than 70% of cases, especially SPan-1 and CA 19-9. The measurement of these two tumor markers makes it possible to detect small pancreatic cancers after using imaging diagnostic procedures.

Adult↗
PubMed1991

Renal function in experimentally induced acute pancreatitis in dogs: how it is affected by the nephrotoxic substance in pancreatic exudate from ascitic fluid.

Renal failure occurring in dogs during experimental acute pancreatitis and the effect on renal function of intravenous injections of ascitic fluid which accumulated during the acute pancreatitis were studied. Five hours after the induction of acute pancreatitis, the accumulation of 200 to 400 ml of ascitic fluid, and an elevation in hematocrit as well as a decreased mean arterial pressure were observed, which suggested hypovolemia due to plasma loss. At the same time, the renal blood flow, glomerular filtration rate, and urinary output decreased significantly. Hypovolemia was observed to be the main cause of renal failure in accordance with previous reports. When the sterile ascitic fluid was injected into healthy dogs, temporary hypotension was observed without changes in the hematocrit. However, the renal blood flow, glomerular filtration rate and urinary output decreased, together with an elevation in renal vascular resistance, even after the hypotension had returned to normal. This study shows that renal failure associated with acute pancreatitis occurred mainly as a direct result of hypovolemia but also that the sterile ascitic fluid contained nephrotoxic substances which were suspected to be unrelated to vasoactive substances or protease. Their removal is therefore necessary for the treatment and prevention of renal failure complicating acute pancreatitis.

Acute Disease↗
PubMed1991

Various tumor markers for small pancreatic cancer with special reference to the present status of pancreatic cancer in Japan and our experience over the past 2 years.

Various tumor markers for detection of small pancreatic cancer less than 4.0 cm of diameter were evaluated and our recent 2 year experience is presented. Even in T1 cancer, 62.5% of the patients (N = 24) had elevated serum CA 19-9 and 56.5% of the patients also had elevated serum SPan-1. However, that of other markers was less than 30% except for CA 50 (60%). In T2 cancer, the highest sensitivity was observed for SPan-1 (79.6%, N = 54) and that of Ca 19-9 (N = 54) was also high (77.7%). That of other markers was less than 50%. The combination assay of CA 19-9 and SPan-1 in T1 cancer increased sensitivity from a single assay of 62.5% and 56.5%, respectively, to 70%. In T2 cancer, the sensitivity of the combination was 97.1%. All of our cases showed positive results using serum SPan-1 and/or CA 19-9 before confirming the diagnosis with imaging procedures. By applying measurements accurately, the test is a very useful adjunct to the diagnosis of small pancreatic cancer and therefore improves its prognosis.

Adult↗
PubMed1991

Factors affecting the natural transmission of bovine leukaemia virus infection in Queensland dairy herds.

Natural transmission of bovine leukaemia virus (BLV) infection in south-eastern Queensland dairy herds was slow in 2 herds with a low to moderate (13 to 22%) prevalence of infection. Infection spread much more rapidly in a herd that had a higher prevalence (42%) when first tested. In a 13 month study of this herd, the cumulative incidence of infection was 24%. In one herd new infections were confined almost entirely to calves of uninfected dams. Following the end of feeding bulk milk to calves, a common practice in dairy herds, no more calves in this herd became infected. In laboratory experiments, neither prolonged housing of susceptible calves with infected cattle, consumption of drinking water contaminated with infected blood, nor inoculation of sheep with saliva from infected cattle resulted in transmission of BLV infection. Sheep were infected by subcutaneous inoculation of a suspension of purified lymphocytes from an infected heifer. The minimum infective dose was 10(3) lymphocytes, equivalent to the number of lymphocytes in approximately 0.1 microliter blood. Thus, procedures involving the transfer of a very small volume of blood from animal-to-animal have the potential to transmit infection.

Age Factors↗
PubMed1991

[Clinicopathological and histochemical studies of linitis plastica type gastric cancer with special reference to early gastric cancer in the region of the fundic gland].

Early gastric cancer in the region of the fundic gland was found to occur predominantly in women. Many lesions of this type were identified in the posterior wall of the middle portion of the stomach. Histologically, the lesions were classified as poorly differentiated carcinomas in all cases of early cancer. In 9 patients with cancer of linitis plastica type having IIc lesions located in the region of the fundic gland, the tumor focus was also in posterior wall of the middle portion of the stomach. Giant folds were present diffusely in all other portions of the gastric mucosa in these latter cases. These cases also had diffuse infiltration of cancer cells into the submucosa, muscle layer and extraserosal regions. Histologically, the lesions were classified in all cases of linitis plastica type as poorly differentiated carcinomas including signet ring cells. Acid mucopolysaccharides (AMPS) and sialic acid were histochemically detected in the interstitial tissues of early gastric carcinomas and linitis plastica type gastric cancers. The AMPS digestion rates were higher for early cancer tissue. The present results support the hypothesis that early gastric cancer in the region of the fundic gland may occur in conditions favoring tumor growth and may develop into cancer of linitis plastica type.

Adenocarcinoma, Mucinous↗
PubMed1991

Clinicopathological and histochemical studies of linitis plastica type gastric cancer with special reference to early gastric cancer in the region of the fundic gland.

In this study, early gastric cancer in the region of the fundic gland was found to occur predominantly in women. Many lesions of this type were identified in the posterior wall of the middle portion of the stomach. Histologically, the lesions were classified as poorly differentiated carcinomas in all cases of early cancer. On the other hand, in 9 patients with cancer of linitis plastica type having IIc lesions (less than 2.0 cm in diameter) located in the region of the fundic gland, the tumor focus was also in the posterior wall of the middle portion of the stomach. Giant folds were present diffusely in all other portions of the gastric mucosa in these latter cases. These cases also had diffuse infiltration of cancer cells into the submucosa, muscle layer and extraserosal regions. Histologically, the lesions were classified, in all cases of linitis plastica type, as poorly differentiated carcinomas including signet ring cells. Acid mucopolysaccharides (AMPS) and sialic acid were histochemically detected in the interstitial tissues of early gastric carcinomas and linitis plastica type gastric cancers. The AMPS digestion rates were higher for early cancer tissue. The present results support the hypothesis that early gastric cancer in the region of the fundic gland may occur in conditions favorable to tumor growth and may develop into cancer of linitis plastica type.

Adult↗
PubMed1990

An immunohistological study of breast cancer--with special reference to the expression of carbohydrate antigens and estrogen receptor status.

An investigation carried out on 100 cases of primary breast cancer, both clinicopathologically and immunohistologically, revealed estrogen receptor (ER)-positive cases to be found significantly more often in early stage cancer than advanced stage cancer. On the other hand, ER negative cases were found to have a greater incidence of high-grade lymph node metastasis and were seen significantly more frequently in large tumors. Span-1, CA19-9, and SLEX antigens were detected in 33 per cent, 38 per cent, and 64 per cent of the total cases, respectively and the ratio of ER negative cases was significantly higher in each antigen positive group. Irrespective of the presence or absence of lymph node metastasis, ER negative cases were found significantly more often in antigen-positive groups than in their counterparts and tumor size tended to be greater in the antigen-positive cases. The results of this study thus indicated that the disease progression in breast cancer appears to be correlated with ER status and carbohydrate antigen expression.

Antigens, Neoplasm↗
PubMed1990

[Analysis of factors affecting family function].

The purpose of this study was to identify the degree of family function and to determine factors influencing family function. The subjects for this study were 451 adults and high school students among the general population from J city. Data were collected by questionnaire from Sept. 1 to Nov. 30, 1989. The measurement tool was the Family Function Questionnaire (APGAR) developed by Smilkstein. Data were analysed by statistical methods including Mean, S.D, t-test and ANOVA. The following results were obtained: 1. The mean Family APGAR score was 5.70 +/- 0.11, in a range from 0-10. 2. Scores from 0 to 6, which fall into the dysfunctional family range, were recorded for 266 families (59.6%). 3. Significant variables among general characteristics influencing family function were age, sex, marital status, educational levels, monthly income and occupation (p less than .001). 4. Significant variables among family characteristics influencing family function were family life cycle (p less than .01), utilization of family resources (p less than .01) and family atmosphere (p less than .001).

Family↗