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Chung YJ, Kim KM, Choi JR, Choi SW, Rhyu MG. Relationship between intratumor histological heterogeneity and genetic abnormalities in gastric carcinoma with microsatellite instability. Int J Cancer 1999; 82:782-8. [PMID: 10446441 DOI: 10.1002/(sici)1097-0215(19990909)82:6<782::aid-ijc2>3.0.co;2-#] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Microsatellite instability (MSI)-mutator phenotype variably targets microsatellite-like sequences in coding regions of cancer-related genes. Intratumor histological heterogeneity of gastric carcinoma with MSI was evaluated and found to be linked with the topographical distribution of MSI-associated mutations. One hundred fifty tumor sites derived from 51 gastric cancer patients were microdissected with respect to histological and topographical clonality. We found 11 gastric carcinomas with a high frequency of MSI, which were characterized by marked intratumor genetic heterogeneity arising from the progressive MSI-phenotype that was associated with frameshift mutations on multiple cancer-related genes. The 11 MSI-tumor cases manifested the MSI-phenotype in 34 of 36 tumor sites tested, but not in the remaining 2 sites. Most (88.2%, 30 of 34) MSI-positive sites and most (96.2%, 25 of 26) tumor sites harboring the frameshift mutations in transforming growth factor-beta receptor type II gene exhibited intestinal-type histology, whereas the 2 MSI-negative sites were found to be of diffuse-type histology without accompanying frameshift mutations. In 2 of 5 cases harboring E2F-4 frameshift mutations, glandular structures of intestinal-type tumor were likely to be variably differentiated in relation to the extent of the mutation, i.e., the number of mutated alleles and the size of deleted or inserted base pairs. Overall, the intratumor histological heterogeneity of gastric carcinoma with MSI was associated with the progressive frameshift mutations in transforming growth factor-beta receptor type II and E2F-4 genes.
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Choi SW, Lee HN, Kang SJ, Kim HO. A case of cutaneous endometriosis developed in postmenopausal woman receiving hormonal replacement. J Am Acad Dermatol 1999; 41:327-9. [PMID: 10426922 DOI: 10.1016/s0190-9622(99)70377-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Cutaneous endometriosis is characterized by the presence of extrauterine endometrial tissue in or under the skin. We report a case of cutaneous endometriosis in postmenopausal woman who was receiving hormonal replacement.
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Abstract
A prospective epidemiologic study found a threshold level for serum vitamin B12, below which an increased risk of breast cancer among postmeno-pausal women was observed. This is the first observation to suggest that B12 status may influence breast carcinogenesis and therefore may be a modifiable risk factor for breast cancer prevention.
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Yang JM, Kim SS, Kim JI, Ahn BM, Choi SW, Kim JK, Lee CD, Chung KW, Sun HS, Park DH, Thurman RG. The metabolic effects of estriol in female rat liver. J Korean Med Sci 1999; 14:277-85. [PMID: 10402170 PMCID: PMC3054389 DOI: 10.3346/jkms.1999.14.3.277] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The effects of estriol on oxygen uptake, glucose release, lactate and pyruvate production, beta-hydroxybutyrate and acetoacetate production in perfused rat liver as well as, carbon uptake in rat liver and intracellular calcium in isolated Kupffer cells were investigated. Basal oxygen consumption of perfused liver increased significantly in estriol or ethanol-treated rats. But these increased effects were blocked by gadolinium chloride pretreatment. In a metabolic study, pretreatment with estriol resulted in a decrease in glucose production and in glycolysis while an increase in ketogenesis. A more oxidized redox state of the mitochondria was indicated by increased ratios of perfusate [lactate]/[pyruvate] and decreased ratios of perfusate [beta-hydroxybutyrate]/[acetoacetate]. Carbon uptake of Kupffer-cell increased significantly in estriol-treated rats. But these increased uptake were not shown in rats pre-treated by gadolinium chloride blocking phagocytosis. In isolated Kupffer cells from estriol-treated rats, intracellular calcium was more significantly increased after addition of lipopolysaccharide (LPS) than in controls. These findings suggest that the metabolic effects of estriol (two mg per 100 mg body wt) can be summarized to be highly toxic in rat liver, and these findings suggest that oral administration of estrogens may induce hepatic dysfunctions and play a role in the development of liver disease.
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Abstract
Leiomyosarcoma is a rare tumor that originates in the smooth muscle, usually in the gastrointestinal tract, the retroperitoneum and the genitourinary tract. The omentum has been rarely reported as a primary site of occurrence with leiomyosarcoma. A 72 year-old woman, with palpable mass on the left upper quadrant of abdomen and weight loss, was admitted to St. Paul's Hospital. Abdominal CT scan showed a 12 x 8 x 8 cm-sized cystic mass in the left upper quadrant of the abdomen. Endoscopic ultrasonography showed a large cystic mass between the stomach and the liver, which was 1.6 cm length in wall thickness. Laparotomy and resection of the mass was performed. A 12 x 8 x 8 cm-sized mass, originated from the lesser omentum, was discovered near the lesser curvature of the stomach. Microscopic examination revealed spindle-shaped cells with 7-8 mitoses per high power field. She was diagnosed as primary leiomyosarcoma originated from the lesser omentum.
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Choi SW, Park SW, Lee KY, Kim KM, Chung YJ, Rhyu MG. Fractional allelic loss in gastric carcinoma correlates with growth patterns. Oncogene 1998; 17:2655-9. [PMID: 9840929 DOI: 10.1038/sj.onc.1202188] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To gain an insight into the genetic events underlying morphological phenotypes, we analysed 58 gastric carcinoma tissues for the genome-wide allelotype study using microsatellite markers. Based on a binomial distribution, loss of heterozygosity (LOH) that was significantly more frequent than expected (P<0.05) thus interpreted as nonrandom LOH selected during tumorigenesis. The overall extent of chromosomes undergoing LOH i.e. fractional allelic loss (FAL, the ratio of LOH-positive markers to the total number of informative markers) was measured in each tumor patient. Nonrandom LOH was found on 17p (48.0%), 18q (38.4%), 13q (38.1%) and 9p (36.4%). Overall, there were no significant phenotypes correlated with allelic loss on specific chromosome regions. Based on a bimodal distribution of FAL values with two peaks bordered by a mean of 0.233, tumors were classified into LOH-related (>0.233) and LOH-unrelated (<0.233) types. Among 24 patients with LOH-related tumors, increase in the infiltrative type of growth pattern was found to correspond with a significant trend of increasing FAL values. This study shows that the growth pattern of gastric carcinoma is correlated with FAL, suggesting that a malignant phenotype is influenced by LOH event.
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Choi SW, Park HY, Rubeiz NG, Sachs D, Gilchrest BA. Protein kinase C-alpha levels are inversely associated with growth rate in cultured human dermal fibroblasts. J Dermatol Sci 1998; 18:54-63. [PMID: 9747662 DOI: 10.1016/s0923-1811(98)00025-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Human dermal fibroblasts are known to express the alpha, delta, epsilon, and zeta isoforms of protein kinase C (PKC). We asked whether the growth of human dermal fibroblasts correlates with expression of a particular PKC isoform. Of total PKC activity measured in the presence of calcium, a condition permissive for activation of all PKC isoforms, 75%) was contributed by PKC-alpha, suggesting that PKC-alpha is the dominant isoform in human dermal fibroblasts. We then further studied PKC-alpha under different culture conditions and in cultures derived from different aged donors. In both subconfluent and confluent cultures, total PKC activity and the level of PKC-alpha protein were consistently higher in slowly proliferating adult cells than in more rapidly proliferating newborn cells. Moreover, in newborn fibroblasts density strongly influenced these parameters. At subconfluent density, when cells were dividing exponentially, total PKC activity was 345+/-63 cpm/,ug protein; whereas at confluent density, when cells were growth arrested, it was 6-7 fold higher, 2334+/-50 cpm/ug protein. Immunoblot analysis using a specific monoclonal antibody against PKC-alpha exhibited a similar 6-7 fold increase in the level of PKC-alpha protein at confluent density. However, in adult cells, density had no influence on the already high total activity or level of PKC-alpha. To further determine whether the increases in the levels of total PKC activity and the alpha isoform correlate with the decreased growth rate, a characteristic of both adult donor-derived and confluent cells, total PKC activity and the level of PKC-alpha in subconfluent quiescent cells was compared to that in paired exponentially growing cells at the same density. Total PKC activity was 8836+/-71 cpm/microg protein in subconfluent quiescent cells versus 4415+/-175 cpm/microg protein in dividing cells. The level of PKC-alpha protein was also 2-3 fold higher in quiescent than in growing cultures. However, the amount of PKC-alpha mRNA in these two conditions was identical as determined by northern blot analysis. Taken together, these results suggest an inverse relationship between the levels of total PKC activity and PKC-alpha protein and fibroblast growth rate that is regulated at the post-transcriptional level.
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Choi SW, Cook KF, Dodd BG. Parameter recovery for the partial credit model using MULTILOG. JOURNAL OF OUTCOME MEASUREMENT 1998; 1:114-42. [PMID: 9661717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
This study investigated parameter recovery for the partial credit model using the MULTILOG computer program. Factors studied were the sample size and the number of item parameters, which were manipulated by systematically varying the number of steps per item and the number of items. The findings suggest that the ratio of sample size to number of item parameters being estimated as a "rule of thumb" can be a more complete guideline when the number of steps per item is taken into account. Accurate estimation of ability can be obtained across all conditions, even with sample sizes as small as 250. With regard to estimation of step values, however, more caution is warranted. Accurate estimation of the step values of items which have more categories requires larger sample sizes for a given number of total parameters to be estimated.
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Abstract
BACKGROUND/AIMS Diminished folate status appears to promote colonic carcinogenesis by, as of yet, undefined mechanisms. Impaired DNA repair plays a significant role in the evolution of many colon cancers. Since folate is essential for the de novo synthesis of nucleotides and since folate depletion has previously been associated with excessive DNA strand breaks, it was hypothesised that folate depletion may impair DNA repair. Studies were therefore performed to examine whether folate depletion affects the two major categories of DNA repair. METHODS Study 1: eight weanling male Sprague-Dawley rats were fed on diets containing either 0 or 8 mg folate/kg diet with 1% succinylsulphathiazole for four weeks. After viable colonocytes had been harvested, DNA excision repair was evaluated by a single cell gel electrophoresis assay. Study 2: eighteen animals were fed on similar diets for five weeks. Also in study 2, 18 additional rats were fed on the same defined diet without succinylsulphathiazole for 15 weeks. Weekly injections with the procarcinogen, 1,2-dimethylhydrazine (20 mg base/kg), were administered to the latter group of animals. Five microsatellite loci from different chromosomes were investigated for instability in hepatic and colonic DNA. RESULTS In study 1, a significantly retarded rate of DNA excision repair was observed in the folate deficient colonocytes compared with controls (p < 0.05). In study 2, there was no evidence of instability at the five microsatellite loci associated with either short or long term folate depletion. CONCLUSIONS Folate deficiency impairs DNA excision repair in rat colonic mucosa; a similar degree of deficiency, even when administered in conjunction with a colonic carcinogen, did not produce evidence of a widespread defect in mismatch repair.
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Ahn JM, Lee JH, Choi SW, Kim WE, Omn KS, Park SK, Kim WG, Roh JR, Min BG. Implantable control, telemetry, and solar energy system in the moving actuator type total artificial heart. Artif Organs 1998; 22:250-9. [PMID: 9527287 DOI: 10.1046/j.1525-1594.1998.06014.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The moving actuator type total artificial heart (TAH) developed in the Seoul National University has numerous design improvements based upon the digital signal processor (DSP). These improvements include the implantability of all electronics, an automatic control algorithm, and extension of the battery run-time in connection with an amorphous silicon solar system (SS). The implantable electronics consist of the motor drive, main processor, intelligent Li ion battery management (LIBM) based upon the DSP, telemetry system, and transcutaneous energy transmission (TET) system. Major changes in the implantable electronics include decreasing the temperature rise by over 21 degrees C on the motor drive, volume reduction (40 x 55 x 33 mm, 7 cell assembly) of the battery pack using a Li ion (3.6 V/cell, 900 mA.h), and improvement of the battery run-time (over 40 min) while providing the cardiac output (CO) of 5 L/min at 100 mm Hg afterload when the external battery for testing is connected with the SS (2.5 W, 192.192, 1 kg) for the external battery recharge or the partial TAH drive. The phase locked loop (PLL) based telemetry system was implemented to improve stability and the error correction DSP algorithm programmed to achieve high accuracy. A field focused light emitting diode (LED) was used to obtain low light scattering along the propagation path, similar to the optical property of the laser and miniature sized, mounted on the pancake type TET coils. The TET operating resonance frequency was self tuned in a range of 360 to 410 kHz to provide enough power even at high afterloads. An automatic cardiac output regulation algorithm was developed based on interventricular pressure analysis and carried out in several animal experiments successfully. All electronics have been evaluated in vitro and in vivo and prepared for implantation of the TAH. Substantial progress has been made in designing a completely implantable TAH at the preclinical stage.
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Yang JM, Choi SW, Kim SS, Sun HS, Park DH, Han SB, Oh GT, Kim WM. Effects of prostaglandins on ethanol damage in primary cultured rat hepatocytes. Korean J Intern Med 1998; 13:1-9. [PMID: 9538624 PMCID: PMC4531939 DOI: 10.3904/kjim.1998.13.1.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVES Several reports demonstrated that ethanol administration impairs the DNA synthesis in rat hepatocytes. Also, it has been demonstrated that prostaglandin (PG) helps prevent membrane damage by hepatotoxic chemicals. In this study, the authors examined PG's effects on the toxicity of ethanol in the primary culture of rat regenerations. METHODS We examined two kinds of parameters, i.e., DNA synthesis and lipid peroxidation in the primary culture of rat hepatocytes. Hepatocytes were isolated by the collagenase perfusion method. The rate of DNA synthesis was determined by pulse-labelling cultured cells with [3H]-thymidine. Incorporation of (3H)-thymidine was determined by liquid scintillation spectrophotometer. DNA content was measured by the fluorescence spectrophotometer. The lipid peroxidation was assayed with spectrophotometer. RESULTS The results were as follows: 1) PG family (PGA1, PGD2, PGE1, PGE2, PGG2a, PGI2 & Thromboxane B2) stimulated the DNA synthesis of hepatocytes (especially PGD2 and PGE1), 2) ethanol decreased DNA synthesis by clear dose-dependent manner, 3) the combined treatment of PGD2 or PGE1, prevents the decreasing of DNA synthesis, which was induced by ethanol, 4) in ethanol treatment, lipid peroxidation was decreased significantly, but PGD2, PGE1 and PGA1 were not affected, and 5) PGD2, PGE1 and PGA1 decreased lipid peroxidation with ethanol, significantly. CONCLUSIONS From these results, we concluded that PG could be useful for the treatment of degenerative liver disease and alcohol-induced liver disease in the assumption that further studies on the action mechanisms of PG will continue.
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Chung YJ, Park SW, Song JM, Lee KY, Seo EJ, Choi SW, Rhyu MG. Evidence of genetic progression in human gastric carcinomas with microsatellite instability. Oncogene 1997; 15:1719-26. [PMID: 9349506 DOI: 10.1038/sj.onc.1201343] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Mutator phenotype tumors provide unique opportunities to unravel malignant progression because of various gene alterations acquired during clonal tumor evolution. Gastric carcinomas, which have been known to show frequent genetic instability, would be composed of initial gene alterations shared by most tumor areas and subsequent alterations restricted to particular tumor sites. To analyse the timing of genetic events, we examined separate sites of tumor tissue obtained from a given gastric carcinoma patient with microsatellite instability (MSI). Our study included 95 normal/tumor area pairs from 25 patients. Six of the 25 patients (24%) demonstrated various levels of MSI ranging from 7% (two of 30) to 97% (28 of 29) of markers tested in multiple tumor sites. Of the six patients, five manifested frameshift mutations in a tract of ten deoxyadenosines within transforming growth factor beta receptor type II and four demonstrated frameshift mutations in a tract of eight deoxyguanosines within BAX. These mutations were common to all tumor sites regardless of the various level of MSI phenotype, indicating initial events. Two of the six patients exhibited frameshift mutations in mononucleotide repeats of mismatch repair genes, hMSH3 and hMSH6, and the insulin-like growth factor II receptor in restricted tumor areas, indicating additional alterations. Insulin-like growth factor II receptor mutations appear to be caused by hMSH3 and hMSH6 mutations because the former mutations were confined to tumor portions with the latter two mismatch repair lesions. These results provide genetic progression evidence for gastric carcinomas of the mutator pathway. In this pathway, mismatch repair insufficiency initially targets mononucleotide tracts of transforming growth factor beta receptor type II and BAX. During tumorigenesis, primary mismatch repair failure may give rise to the secondary mismatch repair lesions, frameshift mutations of hMSH3 and hMSH6, which result in another tumorigenic mutation in the insulin-like growth factor II receptor.
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Ahn JM, Kim WE, Choi SW, Min BG, Kim WG. A solar cell system for extension of battery run time in a moving actuator total artificial heart. ASAIO J 1997; 43:M673-6. [PMID: 9360131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
An implantable total artificial heart (TAH) system has strong dependence upon the external battery performance for operation. Even under sophisticated battery management control, the usable external battery performance continues to decrease, which limits TAH performance. One of the ways to overcome this energy problem is to use a solar system (SS). An SS can provide electrical power for the partial TAH drive or battery recharge. This article presents a new concept for use of the solar cell for obtaining double external battery performance. To achieve it, numeric simulations were carried out to obtain the proper magnitude of solar parameters. In the TAH used, the battery power for a cardiac output of 4-6 L/min is approximately 17 W/20 min. From simulated results, the optimal power and voltage of the SS were found to be 7 W, Voc = 27 V in the case of the 24 V motor. Each solar cell includes Voc = 0.5 V, Isc = 37 mA/cm2, FF (fill factor) = 0.77, and efficiency = 10%. Based on the simulation, the effect of solar power capacity on battery run time was studied. With use of 6.5 W SS (W 304 x H 245 x D 16 mm, 1.1 kg), battery performance decreased in vitro from 100% (fully charged) to > 55% vs 0% in the conventional battery system after 20 min operation. However, it dropped to below 20% when using W SS (W 192 x H 192 x D 16 cm, 0.6 kg). The results showed doubled battery run time could be obtained compared with a system without the SS. It was concluded that the proposed SS can be put to practical use as a future energy source for a TAH.
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Kim WE, Ahn JM, Choi SW, Min BG. Intelligent Li ion battery management based on a digital signal processor for a moving actuator total artificial heart. ASAIO J 1997; 43:M588-92. [PMID: 9360113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
An intelligent Li Ion battery management (ILBM) system was developed based on a digital signal processor (DSP). Instead of using relatively complicated hardware charging control, a DSP algorithm was used, and favorable characteristics in volume, mass, and temperature increase of the implantable battery were achieved. In vitro tests were performed to evaluate the DSP based algorithm for Li Ion charging control (24 V dc motor input power 16 W, 5 L/min, 100 mmHg afterload). In this article, the first improvement was volume reduction using a Li Ion battery (3.6 V/Cell, 900 mA, seven cells: 25.2 V, 22.7 W). Its volume and mass were decreased by 40% and 50% respectively (40*55*75 mm, 189 g), compared to previously reported results, with total energy capacity increased by 110% (more than 60 min vs 25 min run time in the other battery). The second improvement includes the ILBM, which can control the performance detection for each unit cell and has a low temperature rise. The ILBM's unit cell energy detection was important because the low performance of one cell dropped to 50% of the total performance along with a 20% increase in surface temperature. All electronics for a transcutaneous energy transmission (TET), battery, and telemetry were finalized for hybridization and used for total artificial heat (TAH) implantation.
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Kim YI, Salomon RN, Graeme-Cook F, Choi SW, Smith DE, Dallal GE, Mason JB. Dietary folate protects against the development of macroscopic colonic neoplasia in a dose responsive manner in rats. Gut 1996; 39:732-40. [PMID: 9014775 PMCID: PMC1383400 DOI: 10.1136/gut.39.5.732] [Citation(s) in RCA: 129] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND AND AIMS Diminished folate status is associated with enhanced colorectal carcinogenesis. This study investigated the potential chemopreventive role of dietary folate in the dimethylhydrazine colorectal cancer model. SUBJECTS AND METHODS Sprague-Dawley rats were fed diets containing either 0, 2 (daily dietary requirement), 8 or 40 mg folate/kg diet for 20 weeks. After five weeks of diet, rats were injected with dimethyl-hydrazine (44 mg/kg) weekly for 15 weeks. Fifteen weeks after the first injection of dimethylhydrazine, all rats were killed. Folate status was determined, and the entire colorectum from each rat was analysed for macroscopic and microscopic neoplasms. RESULTS Plasma and colonic folate concentrations correlated directly with dietary folate levels (p < 0.005). The incidence of microscopic neoplasms was similar among the four groups. However, the incidence and the average number of macroscopic tumours per rat decreased progressively with increasing dietary folate levels up to 8 mg/kg diet (p < 0.05). In the strongly procarcinogenic milieu used in this study, folate supplementation at 20 times the basal requirement was associated with rates of macroscopic tumour development that were intermediate, and not statistically distinct, from rates observed at either 0 or 8 mg/kg diet. CONCLUSIONS These data indicate that in this rat model, (a) increasing dietary folate up to four times the basal requirement leads to a progressive reduction in the evolution of macroscopic neoplasms from microscopic foci; and (b) folate supplementation beyond four times the requirement does not convey further benefit.
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Chung YJ, Song JM, Lee JY, Jung YT, Seo EJ, Choi SW, Rhyu MG. Microsatellite instability-associated mutations associate preferentially with the intestinal type of primary gastric carcinomas in a high-risk population. Cancer Res 1996; 56:4662-5. [PMID: 8840981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Most colon cancers exhibiting microsatellite instability (MI), a mutator phenotype of mismatch repair failure, are associated with mutations of the transforming growth factor-beta receptor type II genes (TGF-beta RII). Of intestinal- and diffuse-type gastric carcinomas, the former have been thought to arise from intestinal metaplasia in which gastric mucosa resembles intestinal mucosa. To evaluate the preferential histological type of MI-associated mutations in the development of gastric carcinoma, mutations of TGF-beta RII, p53, and p16 were analyzed for the two types of primary gastric carcinomas showing MI. Of 50 primary gastric carcinomas, including 33 intestinal types and 17 diffuse types, 15 cases (30%) demonstrated MI at 1 or more of the 11 microsatellite markers tested. The 15 MI cases were classified into two groups, widespread MI and low-level MI, based on the number of markers exhibiting the instability. Eleven were widespread MIs, and the remaining four cases were low-level MIs. Ten of the 11 (91%) widespread MIs were of the intestinal type, and 1 case (9%) was of the diffuse type. Of the 11 widespread MIs, 10 cases (91%) demonstrated frameshift mutations within the polyadenylate tract of the TGF-beta RII. The frameshift mutation was rarely detected at p53 and p16 (1 of 11, 9%). In contrast, the four low-level MI cases had no frameshift mutations within the repeat sequences of TGF-beta RII, p53, and p16, but two of the four cases demonstrated base substitution mutations within p53. Our results suggest that mismatch repair failure can mutate the TGF-beta RII and may provide one of the pathways for the development of the intestinal-type gastric carcinoma in high-risk populations.
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143
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Kim YI, Pogribny IP, Salomon RN, Choi SW, Smith DE, James SJ, Mason JB. Exon-specific DNA hypomethylation of the p53 gene of rat colon induced by dimethylhydrazine. Modulation by dietary folate. THE AMERICAN JOURNAL OF PATHOLOGY 1996; 149:1129-37. [PMID: 8863662 PMCID: PMC1865189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Folate deficiency enhances colorectal carcinogenesis in dimethylhydrazine-treated rats. Folate is an important mediator of DNA methylation, an epigenetic modification of DNA that is known to be dysregulated in the early stages of colorectal cancer. This study investigated the effect of dimethylhydrazine on DNA methylation of the colonic p53 gene and the modulation of this effect by dietary folate. Sprague-Dawley rats were fed diets containing 0, 2, 8, or 40 mg of folate/kg of diet. Five weeks after diet initiation, dimethylhydrazine was injected weekly for fifteen weeks. Folate-depleted and folate-replete control animals did not receive dimethylhydrazine and were fed the 0- and 8-mg folate diets, respectively. The extent of p53 methylation was determined by a quantitative HpaII-polymerase chain reaction. In exons 6 and 7, significant p53 hypomethylation was observed in all dimethylhydrazine-treated rats relative to controls (P < 0.01), independent of dietary folate. In exon 8, significant p53 hypomethylation was observed only in the dimethylhydrazine-treated folate-depleted rats compared with controls (P = 0.038) and was effectively overcome by increasing levels of dietary folate (P = 0.008). In this model, dimethylhydrazine induces exon-specific p53 hypomethylation. In some exons, this occurs independent of dietary folate, and in others, increasing levels of dietary folate effectively override the induction of hypomethylation in a dose-responsive manner. This may be a mechanism by which increasing levels of dietary folate inhibit colorectal carcinogenesis.
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Choi SW, Yang JM, Kim SS, Kang SH, Ro HJ, Song KS, Ha HK, Lim KW, Kim JS. A case of combined gastrojejunal and gastrocolic fistula secondary to gastric cancer. J Korean Med Sci 1996; 11:437-9. [PMID: 8934400 PMCID: PMC3054189 DOI: 10.3346/jkms.1996.11.5.437] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
A rare case of gastric cancer associated with gastrojejunal and gastrocolic fistula is presented. A 56-year-old man who had been diagnosed with advanced gastric cancer(Borrmann's type III) 5 months previously was admitted due to watery diarrhea and frequent vomiting for 2 weeks. Fluoroscopic examination was visualized two abnormal passage of contrast medium from the stomach, one to the colon, and the other to the jejunum. Gastrofiberscopy revealed that the tumor on the great curvature of the body appeared to penetrate into the colon, while the other one on the antrum directly invaded into the jejunum. The patient was treated conservatively with total parenteral nutrition and pain control.
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Abstract
We report a case of bilateral ureteral obstruction most likely caused by polyarteritis nodosa. The diagnosis was based upon muscle biopsy which showed typical necrotizing vasculitis in medium size artery in conjunction with microaneurysms in renal angiography. Ureteral obstruction is a rare manifestation of polyarteritis nodosa. This condition is thought to result from vasculitis of periureteral vessels. The patient was managed with prednisolone alone, which resulted in complete resolution of ureteral obstruction on both sides.
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146
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Myung SJ, Yoo B, Lee KH, Yoo MR, Choi SW, Yoo ES, Chi HS, Moon HB. A case of systemic lupus erythematosus developing two years after remission of thrombotic thrombocytopenic purpura. Korean J Intern Med 1996; 11:178-82. [PMID: 8854658 PMCID: PMC4532017 DOI: 10.3904/kjim.1996.11.2.178] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We describe a 17-year-old male who presented with thrombotic thrombocytopenic purpura (TTP) and 2 years thereafter developed central nervous system lupus and nephritis. The association of TTP and systemic lupus erythematosus has been described, but the unusual sequence and chronological separation is very rare.
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Choi SW, Park CH, Silva TM, Zaenker EI, Guerrant RL. To culture or not to culture: fecal lactoferrin screening for inflammatory bacterial diarrhea. J Clin Microbiol 1996; 34:928-32. [PMID: 8815110 PMCID: PMC228919 DOI: 10.1128/jcm.34.4.928-932.1996] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Because of its low yield in unselected specimens, stool culture is often cost ineffective. We tested 55 fecal samples from Fairfax Hospital (46 patients with diarrhea and 9 from controls without diarrhea) for lactoferrin by latex agglutination (LFLA) with the Leukotest (Techlab, Blacksburg, Va.) as a marker for inflammatory diarrhea. Of the 28 samples with Salmonella, Shigella, or Campylobacter infection, 93% had detectable fecal lactoferrin at > or = 1:50 (61% had LFLA titers of > or = 1:400), while 83% of 18 samples with rotavirus or no detectable pathogen were LFLA negative at a titer of 1:50 (100% were negative at 1:400). All 9 controls without diarrhea were LFLA negative at 1:50. The use of fecal lactoferrin to screen for inflammatory diarrhea selects specimens for which stool culture is fivefold more likely to yield an invasive bacterial pathogen (reducing the cost per positive result by over $800) and thus may greatly enhance a cost-effective approach to evaluating diarrheal illness.
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148
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Song JH, Lee C, Chang WH, Choi SW, Choi JE, Kim YS, Cho SR, Ryu J, Pai CH. Short-course doxycycline treatment versus conventional tetracycline therapy for scrub typhus: a multicenter randomized trial. Clin Infect Dis 1995; 21:506-10. [PMID: 8527534 DOI: 10.1093/clinids/21.3.506] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
To assess the clinical efficacy of short-course doxycycline in the treatment of scrub typhus, we compared conventional 7-day tetracycline therapy with 3-day doxycycline therapy in 116 patients. Patients were randomized to receive either tetracycline (500 mg four times daily; n = 50) or doxycycline (100 mg twice daily; n = 66) and were followed for 4 weeks after the completion of treatment. The cure rate was 100% in the tetracycline group and 93.9% in the doxycycline group (P > .05). The two groups did not differ significantly in terms of the interval required for defervescence or for the alleviation of symptoms. There were no relapses in either group. These data suggest that 3-day doxycycline therapy is as effective as conventional 7-day tetracycline therapy for the cure of scrub typhus and the prevention of relapses.
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149
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Abstract
Plasmacytosis, a distinctive proliferative disorder of plasma cells, is characterized by peculiar multiple skin eruptions, lymphadenopathy and polyclonal hypergammaglobulinemia. To date there has been no report of such cases showing remarkable responses to therapeutic agents. We herein report a case of plasmacytosis which developed in a 52-year-old Korean man and showed remarkable improvement with melphalan.
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150
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Kim SW, Choi SW, Cho BK, Houh W, Lee JW. Tuberculosis cutis orificialis: an association with Evans' syndrome. Acta Derm Venereol 1995; 75:84-5. [PMID: 7747548 DOI: 10.2340/00015555758485] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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