Biomedical subjects
Publications and source records attributed to J C Kim.
OBJECTIVE: We examined the CT features of 22 patients with metastatic linitis plastica to the rectum. CONCLUSION: Metastatic linitis plastica to the rectum should be considered when CT shows a long segment of circumferential rectal wall thickening, especially in patients with peritoneal carcinomatosis from gastric cancer. In such patients, CT helps avoid unnecessary extensive surgery.
A human hepatoma cell line, Hep G2 cells are reliable for the study of alcohol-induced hepatotoxicity. In this study, we investigated the effect of an aqueous extract of Polygala tenuifolia WILLDENOW (Polygalaceae) roots (PTAE) on ethanol (EtOH)-induced cytotoxicity in Hep G2 cells. PTAE (0.01-1 microg/ml) dose-dependently inhibited the EtOH-induced interleukin-1alpha (IL-1alpha) secretion. PTAE (0.01-1 microg/ml) also inhibited the EtOH- and IL-1alpha-induced cytotoxicity. Furthermore, we found that PTAE inhibited the IL-1alpha-induced apoptosis of Hep G2 cells. These results suggest that PTAE may prevent the EtOH-induced cytotoxicity through inhibition of the apoptosis of Hep G2 cells.
Isolated splenic metastasis arising from colorectal carcinoma is very rare and there has been only 6 cases reported in the English literature. A new case is presented, and its possible pathogenesis was considered with previously reported cases. A 65-year-old male patient had received a right hemicolectomy for ascending colon cancer 36 months earlier. He was followed up regularly with serial measurement of serum carcinoembryonic antigen (CEA). Rising serum CEA was discovered from 33 months postoperatively and CT revealed an isolated splenic metastasis. He therefore underwent splenectomy, which was proven to be a metastatic adenocarcinoma with similar histological feature to the original tumor. As all reported cases showed elevated serum CEA at the time of metastasis, isolated splenic metastasis might be associated with CEA in regard to its biological functions of immunosuppression and adhesion.
This article reviews the concept of dysplasia and the distinguishing features of dysplastic nevi, including their premalignant potential, their biologic markers of tumor progression, and their reproducibly recognizable clinical and histologic characteristics. An additional emphasis is placed on describing gray zone melanocytic neoplasms with hybrid histopathologic and biologic characteristics between nevi and melanoma. In particular, dysplastic nevi with high-grade and dermal dysplasia and other potentially related, prognostically indeterminate, nevomelanomatoid proliferations (PINM tumors), including the more recently recognized nevoid melanoma and minimal deviation neoplasms, are discussed. Because of their overlapping features with more overtly benign and malignant neoplasms, these lesions may confound precise determination of biologic outcome. Accordingly, the concept of prognostic indeterminacy and the use of the term PINM tumors to connote these problematic lesions are introduced.
The origin and fate of landfill leachate and gas constituents generated during the sequential phases of solid waste transformation and stabilization are emphasized within the perspective of the in situ processes of microbially mediated attenuation. The fundamental biochemical and physicochemical reaction mechanisms are presented in terms of their spatial and temporal dimensions and their significance for transformation of both nonhazardous and hazardous waste constituents. Supporting information from laboratory, pilot-scale and full-scale applications is used as a basis for interpretive analysis and for providing operational guidance and promoting future developments. The diversity, domains, and functional interdependence of the acidogenic, methanogenic, sulfate and nitrate reducing, nitrifying and denitrifying, and methanotrophic consortia are addressed in order to reveal opportunities for landfill process modifications and associated operational optimization. Controlled attenuation, linked with operational and regulatory realities, are used to suggest innovative landfill configurations involving prospective compartmentalization and integrated waste loading, dedicated treatment zones for in situ transformation of waste and leachate constituents with associated gas capture, control and utilization. Monitoring requirements are emphasized to provide guidance and feedback for operational control and environmental compliance. Finally, technology needs for establishing a more unified approach to the development and management of bioreactor landfills are presented.
Angiostatin is a potent angiogenesis inhibitor that is composed of the first four kringles of plasminogen fragment. Angiostatin with one less kringle molecule (kringle 1 to 3) was recently demonstrated to be an effective angiogenic inhibitor. To determine whether recombinant plasminogen kringle 1-3 (rPK1-3) can inhibit the corneal neovascularization induced by potent angiogenic factors; angiogenin, bFGF, or VEGF, hydron polymer discs each containing 2.0 microg of angiogenin, 500 ng of bFGF, or 500 ng of VEGF respectively were implanted into the corneal stroma of 138 rabbit eyes, and then discs each containing 10 microg, 12.5 microg, 20 microg or 30 microg of rPK1-3 were implanted randomly. Discs containing phosphate buffered saline were also implanted as a control. The angiogenesis score on number and length of newly formed vessels on the each of the rabbit's cornea were recorded daily by two observers (blinded). The treated corneas were also examined histologically. Recombinant PK1-3 treated corneas showed less neovascularization induced by all angiogenic factors (p < 0.05). and the extent of inhibition of neovascularization was proportional to the concentration of rPK1-3 (p < 0.05). Histologic examination showed leukocyte infiltration into the corneal stroma on the PBS treated eyes whereas rPK1-3 treated eyes showed only traces of leukocytes. These results of the effective rPK1-3 inhibition of corneal neovascularization induced by angiogenin, bFGF, or VEGF suggest that this angiostatin related fragment, rPK1-3, may be useful in the treatment of various neovascular diseases.
Locomotion of colorectal-carcinoma cells was tested in order to establish whether it might be affected by carcino-embryonic antigen (CEA). CEA production, cell growth and DNA ploidy were measured in 22 colorectal-carcinoma cell lines. A cell-invasion assay was adapted using a transfilter chamber, the lower surface of which was coated with various substrates in the amount of 5 microgram/filter (CEA, type-IV collagen, laminin). Cells infiltrated into the lower surface of the filter were counted over 9-microscope fields (x400). All cell lines produced CEA, 9 producing more than 100 ng/ml medium. Of the total, 8 cell lines were diploid and 14 were aneuploid. Invasiveness, measured by the number of infiltrated cells, was highest in CEA-coated filters, and next highest in type-IV-collagen- and laminin-coated filters, in descending order (p < 0.001-0.05). Invasiveness of each cell line was closely correlated with 2 substrates. Poorly differentiated or advanced-stage tumors were more invasive than well-differentiated or early-stage tumors (p < 0.001-0. 05). However, invasiveness was not associated with DNA ploidy or CEA production. CEA may function as a chemo-attractant as well as an adhesion molecule in colorectal-carcinoma cell lines. In addition, adhesion to CEA appears to be related to type-IV collagen and laminin.
In plants, multiple calmodulin (CaM) isoforms exist in an organism which vary in their primary structures in as much as 32 residues out of their 148 amino acids. These CaM isoforms show differences in their expression patterns and/or target enzyme activation ability. To further understand the biological significance of CaM isoforms, we examined whether CaM isoforms act on specific regulatory targets. In gel overlay assays on various soybean tissue extracts, surprisingly, two soybean CaM isoforms (SCaM-1 and SCaM-4) did not show significant differences in their target binding protein profiles, although they exhibited minor differences in their relative target binding affinities. In addition, both SCaM isoforms not only effectively bound five known plant CaMBPs, but also showed competitive binding to these proteins. Finally, immunolocalization experiments with the SCaM proteins in sections of various tissues using specific antibodies revealed similar distribution patterns for the SCaM isoforms except for root tissues, which indicates that the SCaM isoforms are concomitantly expressed in most plant tissues. These results suggest that CaM isoforms may compete for binding to CaMBPs in vivo. This competitive nature of CaM isoforms may allow modulation of Ca(2+)/CaM signaling pathways by virtue of relative abundance and differential target activation potency.
The presence of the carcinoembryonic antigen (CEA) gene and CEA expression in the liver was tested to identify their possible roles in the liver metastasis of colorectal carcinoma. The CEA gene in the liver was identified by amplifying the CEA-specific N-terminal domain exon with digoxigenin-dUTP labeling in 16 colorectal carcinomas with liver metastases. Next, CEA expression was tested by immunostaining using the anti-CEA monoclonal antibody (T84.66, ATCC). Liver tissues from 13 stomach cancer patients and 12 colorectal cancer patients without liver metastasis were also tested as control groups. Three grades (<25%, 25-50%, and 50%< or =) were given according to the proportion of positive cells. The CEA gene was amplified in the metastatic tumor cells of the liver (2.6 +/- 0.2, mean grade +/- SEM) and their surrounding hepatocytes (1.5 +/- 0.2) in all cases. CEA expression was found in all metastatic tumor cells and 14 cases of the surrounding hepatocytes. Among the control groups, the CEA gene of the hepatocytes was found in 9 cases each of the colorectal and the stomach cancers that did not exhibit CEA expression. The level of serum CEA was related with the numbers and volume of liver metastases, but not with CEA expression in tumor cells and surrounding hepatocytes. The CEA gene in the metastatic tumor cells, not in the hepatocytes, was closely associated with CEA expression in the surrounding hepatocytes (p<0.01). Although the precise mechanism of CEA gene regulation in hepatocytes remains to be proven, the CEA gene in the metastatic tumor of the liver seems to affect CEA expression in the surrounding hepatocytes facilitating liver metastasis in colorectal carcinoma.
The Ca2+ signal is essential for the activation of plant defense responses, but downstream components of the signaling pathway are still poorly defined. Here we demonstrate that specific calmodulin (CaM) isoforms are activated by infection or pathogen-derived elicitors and participate in Ca2+-mediated induction of plant disease resistance responses. Soybean CaM (SCaM)-4 and SCaM-5 genes, which encode for divergent CaM isoforms, were induced within 30 min by a fungal elicitor or pathogen, whereas other SCaM genes encoding highly conserved CaM isoforms did not show such response. This pathogen-triggered induction of these genes specifically depended on the increase of intracellular Ca2+ level. Constitutive expression of SCaM-4 and SCaM-5 in transgenic tobacco plants triggered spontaneous induction of lesions and induces an array of systemic acquired resistance (SAR)-associated genes. Surprisingly, these transgenic plants have normal levels of endogenous salicylic acid (SA). Furthermore, coexpression of nahG gene did not block the induction of SAR-associated genes in these transgenic plants, indicating that SA is not involved in the SAR gene induction mediated by SCaM-4 or SCaM-5. The transgenic plants exhibit enhanced resistance to a wide spectrum of virulent and avirulent pathogens, including bacteria, fungi, and virus. These results suggest that specific CaM isoforms are components of a SA-independent signal transduction chain leading to disease resistance.
OBJECTIVE: To determine whether amniotic membrane transplantation can be used to treat symptomatic bullous keratopathy displaying poor visual potential. METHODS: Amniotic membrane transplantation was performed at 5 centers on 50 consecutive eyes (50 patients) with symptomatic bullous keratopathy and poor visual potential. The underlying causes of bullous keratopathy included aphakia (9 eyes), pseudophakia (19 eyes), failed grafts (9 eyes), and others (13 eyes). RESULTS: During the follow-up period of 33.8 weeks (3-96 weeks) after amniotic membrane transplantation, 43 (90%) of 48 eyes with intolerable pain preoperatively became pain free postoperatively. Among the 5 eyes with residual pain, 3 received repeated amniotic membrane transplantation, 1 required a conjunctival flap for pain relief, and 1 had reduced pain. Epithelial defects in 45 (90%) of 50 eyes created and covered by amniotic membrane healed rapidly within 3 weeks. Only 4 eyes (8%) showed recurrent surface breakdown. Epithelial edema or bullae recurred in a smaller area in 5 eyes (10%) and pseudopterygium developed in 1 eye. CONCLUSION: Amniotic membrane transplantation can be considered as an alternative to conjunctival flaps in alleviating pain, promoting epithelial healing, and preserving cosmetic appearance in patients with symptomatic bullous keratopathy and poor visual potential.
Although hamartomatous or hyperplastic polyps are rarely accompanied by adenomatous or carcinomatous foci, the role of APC (MIM# 175100) mutations in these polyps is not clear. The neoplastic potential of these polyps was assessed with regard to somatic mutation of the first 14 exons of APC. DNA from 14 hamartomatous polyps (12 patients with juvenile polyp, JP; two patients with Peutz-Jeghers syndrome, PJS) and 27 hyperplastic polyps was used. Exons 1-14 of APC were amplified using verified oligonucleotide primers, and PCR-SSCP analysis was performed. Translation-terminating mutation in exon 15 was also screened using the protein truncation test. All mutations found were transitions or transversions with heterozygous alleles of both wild-type and mutant APC in exons 2, 9, 10, and 11. Four hamartomatous polyps (three from JP and one from PJS) showed seven, new mutations and one common APC variant (codon 486), whereas no hyperplastic polyps demonstrated mutation. APC mutation was not correlated with previous history of colorectal carcinoma or number of polyps. Since all mutations were missense or silent mutations occurred in exons not previously known to have functionally relevant area, their phenotypic implication appeared to be limited.
PURPOSE: Carcinoembryonic antigen is assumed from the results of several experiments to be associated with invasion of colorectal carcinoma by adhesion or contact inhibition. The patterns and the intensity of carcinoembryonic antigen distribution in colorectal carcinoma were assessed to verify whether they were correlated with malignant potential from those biologic characteristics. METHODS: Carcinoembryonic antigen distribution was tested in the archival samples of 149 colorectal carcinomas by immunohistochemistry, using three characterized anti-carcinoembryonic antigen monoclonal antibodies: T84.66, PR1A3, and PR3B10. The distribution patterns in neoplastic tissue were categorized into unstained, apicoluminal, and diffuse cytoplasmic patterns. Tumor, invasive tumor margin, and tissue surrounding the tumor were examined. RESULTS: Although all three antibodies revealed a positive correlation, T84.66 showed better discrimination than the others. Although none of the negative staining of the tumor or invasive tumor margin showed recurrence, the apicoluminal pattern showed recurrence, and the diffuse pattern showed the most frequent recurrence (P < 0.01). Recurrence was also associated with staining intensity in the apicoluminal pattern in both the tumor and invasive tumor margin (P < 0.05). Infiltrative tumor growth and lymph node metastasis were more frequent in cases of positive staining in tissue surrounding the tumor. Patients with the apicoluminal pattern achieved longer survival than patients with the diffuse-cytoplasmic pattern in the invasive tumor margin (P = 0.024) by a multivariate analysis including tumor stage and histologic differentiation. CONCLUSION: The distribution of carcinoembryonic antigen in tumors and surrounding tissue seems to be closely correlated with invasiveness and metastatic behavior in colorectal carcinoma. Carcinoembryonic antigen immune staining can be considered as an efficient tool to determine groups with risk of recurrence.
An efficient procedure for the preparation of 4-hydroxy-3-{1,2,3,4-tetra-hydro-3-[4-(4-triflu-oromethylbenzyl oxy)phenyl]-1-naphthyl}thiocoumarin (thioflocoumafen, 1a and 1b) is described. The key step in the synthesis involves the condensation reaction of 3-(4-methoxyphenyl)-1-tetralol (2) with 4-hydroxy-1-thiocoumarin (3).
OBJECTIVE: This study was undertaken to examine whether oligohydramnios in women with preterm premature rupture of membranes is associated with evidence of fetal, amniotic, and maternal inflammatory responses. STUDY DESIGN: Amniotic fluid index was measured before the performance of amniocentesis in patients with preterm premature rupture of membranes. Fifty-nine patients who were delivered of preterm neonates (gestational age </=35 weeks) within 3 days of amniocentesis were included in this study. Amniotic fluid was cultured for aerobic and anaerobic bacteria and for genital mycoplasmas. The intensity of the inflammatory response was evaluated by the following: presence of clinical and histologic chorioamnionitis; amniotic fluid concentrations of interleukin 6, interleukin 1beta, and tumor necrosis factor alpha; amniotic fluid white blood cell count; and interleukin 6 concentrations in umbilical cord plasma at birth. Proinflammatory cytokines were measured with specific and sensitive immunoassays. RESULTS: Thirty-two percent (19/59) of patients had an amniotic fluid index </=5 cm. Patients with an amniotic fluid index </=5 cm had significantly higher rates of positive amniotic fluid culture results and clinical and histologic chorioamnionitis; higher median amniotic fluid concentrations of interleukin 6, interleukin 1beta, and tumor necrosis factor alpha; and higher median cord plasma concentrations of interleukin 6 than did those with an amniotic fluid index >5 cm (positive amniotic fluid culture result, 79% [15/19] vs 30% [12/40]; clinical chorioamnionitis, 37% [7/19] vs 5% [2/40]; histologic chorioamnionitis, 100% [17/17] vs 69% [24/35]; median amniotic fluid interleukin 6 concentration, 13.5 ng/mL; range, 0.2-142.2 ng/mL vs 3.0 ng/mL and 0.001-115.2 ng/mL; median amniotic fluid interleukin 1beta concentration, 348.0 pg/mL; range, 0.7->80, 000 pg/mL vs 36.6 pg/mL and 0-2075 pg/mL; median amniotic fluid tumor necrosis factor alpha concentration, 132.0 pg/mL; range, 0-1600 pg/mL vs 11.2 pg/mL and 0-1305 pg/mL; median cord plasma interleukin 6 concentration, 49.7 pg/mL; range, 4.4-7400 pg/mL vs 9. 1 pg/mL and 0-5211 pg/mL; P <.05 for each). There was no significant difference between the 2 groups of patients in the mean umbilical artery pH at birth. CONCLUSION: Oligohydramnios in women with preterm premature rupture of membranes is associated with an inflammatory response in the fetal, amniotic, and maternal compartments.
PURPOSE: To study the possible mechanisms of cataractogenesis by evaluating the characteristics of cataractous lens epithelial cells (LECs) in different types of human cataract. SETTING: Kangnam St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea. METHODS: Lens epithelial cells attached to the anterior capsules in eyes with nuclear or anterior subcapsular were analyzed for morphological characteristics by electron microscopy and for cellular characteristics by immunohistochemistry. RESULTS: Human LECs beneath the anterior capsule were degenerated in nuclear cataracts and were transdifferentiated in anterior polar cataracts. In senile nuclear cataractous lenses, LECs beneath the anterior capsule showed degenerative changes in morphology. In nuclear cataracts, LECs were immunohistochemically positive for cytokeratin and vimentin, while those in anterior polar cataracts were positive for vimentin only. The LECs of anterior subcapsular cataracts were transdifferentiated into spindle-shaped fibroblast-like cells without cellular junctions and embedded within a fibrillar meshwork mass. The extracellular matrixes in the anterior capsule of anterior subcapsular cataracts were immunohistochemically positive for fibronectin, laminin, collagen type I, and collagen type IV. CONCLUSIONS: Lens epithelial cells in different types of cataracts have distinct cellular characteristics and may possess a bipotential nature with the ability to transdifferentiate into mesenchymal cells. This may be an underlying mechanism for the development of cataract and capsule opacification.
PURPOSE: To evaluate the effectiveness and therapeutic role of preoperative transarterial chemoembolization (TACE) of hepatoblastoma. MATERIALS AND METHODS: Four patients (one boy, three girls) with unresectable hepatoblastoma were treated twice with preoperative TACE in an effort to improve the surgical and clinical outcome. The patients ranged in age from 8 to 27 months (mean, 15 months). The first TACE was performed superselectively in tumor feeding arteries. The second TACE was performed 3 weeks later. Surgical hepatic resection was performed 1 month after the second TACE. Contrast-enhanced computed tomography (CT) was used to evaluate changes in size, volume, internal texture, and margin of the masses. The toxicity of the chemotherapeutic drugs was evaluated by blood chemistry analysis (AST/ALT, alpha-FP) performed before and after TACE, and after surgery. RESULTS: TACE allowed subsequent surgical resection in all four patients, who remained disease free 16-52 months after operation. There were no major problems related to TACE. There was no chemotherapeutic agent toxicity from TACE. The average largest diameters and volumes of the tumors decreased by 31% (8.3 to 5.6 cm) and 69% (317 to 93 cm2), respectively. CONCLUSION: TACE provided subsequent successful surgical resection and good long-term results in all four patients. The hepatoblastomas were initially considered inoperable because of extensive hepatic involvement and indistinct margins.
Naringin, a bitter compound in citrus fruits, was transglycosylated by Bacillus stearothermophilus maltogenic amylase reaction with maltotriose to give a series of mono-, di-, and triglycosylnaringins. Glycosylation products of naringin were observed by TLC and HPLC. The major glycosylation product was purified by using a Sephadex LH-20 column. The sturcture was determined by using MALDI-TOF MS, methylation analysis, and (1)H and (13)C NMR. The major transglycosylation product was maltosylnaringin, in which the maltose unit was attached by an alpha-1-->6 glycosidic linkage to the D-glucose moiety of naringin. This product was 250 times more soluble in water and 10 times less bitter than naringin.