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Biomedical subjects

Eun Jung Lee

Publications and source records attributed to Eun Jung Lee.

At least 19 recordsLinked to original sources

S100A9 induces tissue remodeling of human nasal epithelium in chronic rhinosinusitis with nasal polyp.

BACKGROUND: Chronic inflammation triggers tissue remodeling in human nasal epithelial (HNE) cells. S100A9, a protein secreted by inflammatory cells, exhibits potent proinflammatory activity. However, its effect on HNE cell remodeling, such as squamous metaplasia, remains unclear. Therefore, this study aimed to determine the effects and underlying pathways of S100A9 on HNE cell remodeling and investigate its clinical implications in chronic rhinosinusitis (CRS). METHODS: Cultured HNE cells were treated with S100A9. Bulk RNA sequencing was performed to analyze gene ontology (GO). Ingenuity pathway analysis (IPA) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were also analyzed. Additionally, immunohistochemistry and multiplex immunofluorescence were performed on tissue samples obtained from 60 patients, whose clinical informations were also reviewed. RESULTS: GO enrichment analysis indicated that S100A9 induced tissue remodeling in HNE cells toward squamous metaplasia. IPA and KEGG commonly showed that S100A9 affected HNE cells associated with the IL-17 signaling pathway, including target molecules such as matrix metalloproteinase 1 (MMP1) and small proline-rich protein 2A (SPRR2A). Squamous metaplasia with a marked expression of S100A9 was observed in 50% of CRS with nasal polyps (CRSwNPs). In addition, in multiplex immunofluorescence, the S100A9 in sub-epithelium was co-expressed with myeloperoxidase, a neutrophil marker, and MMP1 and SPRR2A were strongly expressed in epithelial remodeling. Clinically, the expression of S100A9 correlated with sino-nasal outcome test-22 (r = 0.294, p = 0.022) and Lund-Mackay scores (r = 0.348, p = 0.006). CONCLUSION: S100A9 induces tissue remodeling in HNE cells. Its increased expression in CRSwNP, particularly squamous epithelium, correlates with disease severity. This suggests the clinical potential of S100A9 as a biomarker for CRS severity.

Humans↗

o-Phenylene-bridged Cp/sulfonamido titanium complexes for ethylene/1-octene copolymerization.

The Suzuki-coupling reaction of 2-(dihydroxyboryl)-3,4-dimethyl-2-cyclopenten-1-one and 2-(dihydroxyboryl)-3-methyl-2-cyclopenten-1-one with 2-bromoaniline derivatives affords cyclopentenone compounds from which cyclopentadiene compounds, 4,6-R'(2)-2-(2,5-Me2C5H3)C6H2NH2 and 4,6-R'(2)-2-(2,3,5-Me3C5H2)C6H2NH2 are prepared. After sulfonation of the -NH2 group with p-TsCl, metallation is carried out by successive addition of Ti(NMe2)4 and Me2SiCl2 affording o-phenylene-bridged Cp/sulfonamido titanium dichloride complexes, [4,6-R'(2)-2-(2,5-Me2C5H2)C6H2NSO2C6H4CH3)]TiCl2 (R'=H, ; R'=Me, ; R'=F, ) and [4,6-R'(2)-2-(2,3,5-Me3C5H)C6H2NSO2C6H4CH3)]TiCl2 (R'=H, ; R'=Me, ; R'=F, ). The molecular structures of and [2-(2,5-Me2C5H2)C6H4NSO2C6H4CH3)]Ti(NMe2)2 are determined by X-ray crystallography. The Cp(centroid)-Ti-N angle in is smaller (100.90 degrees) than that observed for the CGC (constrained-geometry catalyst), [Me2Si(eta5-Me4Cp)(NtBu)]TiCl2 (107.6 degrees) indicating a more "constrained feature" in than in the CGC. Complex shows the highest activity among the newly prepared complexes in ethylene/1-octene copolymerization but it is slightly inferior to the CGC in terms of activity, comonomer-incorporation ability, and molecular weight of the obtained polymers.

Journal Article↗

Intracellular IL-4, IL-10, and IFN-gamma levels of leukemic cells and bone marrow T cells in acute leukemia.

The quantitative levels of intracellular cytokines IL-4, IL-10, and IFN-gamma (ie, the number of bound PE-conjugated antibody molecules/cell) of leukemic cells and bone marrow T cells (bmT cells) of acute leukemia patients were analyzed by flow cytometry. One hundred, thirty-one (95 AML, 25 ALL, 11 ABL) patients were studied. The leukemic cell IL-4 level was highest in the monocytic AML group (1735 +/- 1056) and lowest in the dysplastic AML group (960 +/- 545). The IFN-gamma level was highest in the acute promyelocytic leukemia (APL) group (495 +/- 159), and lowest in the ALL group (252 +/- 119). The IL-10 level was not significantly different among the diagnosis groups. In bmT cells, the IL-10 level was highest in the dysplastic AML group (972 +/- 1049) and lowest in the APL group (397 +/- 352). The leukemic cell cytokine levels were lowest and bmT cell cytokine levels were highest in the dysplastic AML group. There were no significant correlations of these cytokine levels with 2-yr survival rate, complete remission (CR) rate, or relapse rate. The cytokine levels of bmT cells at the time of CR became normal and were not different among the diagnosis groups. In summary, leukemic cell and bmT cell cytoplasmic expression profiles of IL-4, IL-10, and IFN-gamma are characteristic for each diagnostic group of acute leukemia patients and the profiles of bmT cells are normal at the time of CR.

Acute Disease↗

Rapid fecal cytokeratin-19 test and fecal occult blood test in screening for gastrointestinal diseases.

To evaluate the screening power of the fecal cytokeratin-19 test (CK-19) and the fecal occult blood test (FOBT), we performed rapid fecal CK-19 and FOBT tests on 515 stool samples from patients with various GI diseases and 814 stool samples from control patients. The rapid fecal CK-19 test (developed by DiNonA Research Institute, Seoul, Korea) is based on gold immunochromatography and has a sensitivity of 1 ng/ml. The positive rate of the FOBT was 2.1% in controls, 14.0% in GI cancer patients, 3.5% in GI inflammation patients, 11.7% in bone marrow transplant (BMT) patients, and 6.0% in childhood diarrhea patients. Except for the GI inflammation patients, the patients' positive rates for FOBT were all higher than the controls (p <0.05). The positive rate of the fecal CK-19 test was 8.2% in controls, 42.1% in GI cancer patients, 66.0% in GI inflammation patients, 84.8% in BMT patients, and 19.9% in childhood diarrhea patients. In all of the patient groups, positive rates for the CK-19 test were higher than in the controls (p <0.05). The fecal CK-19 test was more frequently positive (42.1%) in GI cancer patients than the FOBT; if both tests were used, the sensitivity was 49.1%. The fecal CK-19 test (but not the FOBT) gave a higher positive rate in GI inflammation patients than the controls, suggesting that the CK-19 test could serve as a screening test for GI inflammation. The highest positive rate of the fecal CK-19 test was found in the BMT group, indicating that significant GI epithelial desquamation had occurred. Although the positive rate of the fecal CK-19 test in childhood diarrhea patients was higher than in the controls, it was much lower than in adults with GI inflammatory disease. Evidently, children with GI inflammation do not desquamate as much intestinal epithelium as adult patients with GI inflammation. This study shows that the rapid fecal GK-19 test, used in conjunction with the FOBT, may be a valuable screening technique for GI diseases and can assist physicians in the differential diagnosis of GI diseases.

Adult↗

Non-small cell lung cancer: prospective comparison of integrated FDG PET/CT and CT alone for preoperative staging.

PURPOSE: To evaluate prospectively the accuracy of integrated positron emission tomography (PET) and computed tomography (CT) with use of fluorodeoxyglucose (FDG), compared with that of stand-alone CT, for the preoperative staging of non-small cell lung cancer, with surgical and histologic findings used as the reference standard. MATERIALS AND METHODS: Institutional review board approval and patient informed consent were obtained. From November 2003 to February 2004, 106 patients (78 men, 28 women; mean age, 56 years) with non-small cell lung cancer underwent curative surgical resection (tumor resection and lymph node dissection) after stand-alone CT followed by integrated FDG PET/CT. Tumor stages were determined by using the TNM and American Joint Committee on Cancer staging systems. Histopathologic results served as the reference standard. Statistically significant differences in tumor staging between integrated PET/CT and stand-alone CT were determined with P < .05 obtained by using the McNemar test or with a generalized estimating equation. RESULTS: The primary tumor was correctly staged in 84 patients (79%) at stand-alone CT and in 91 patients (86%) at integrated FDG PET/CT (P = .25). For the depiction of malignant nodes, the sensitivity, specificity, and accuracy of CT were 70% (23 of 33 nodal groups), 69% (248 of 360), and 69% (271 of 393), respectively, whereas those of PET/CT were 85% (28 of 33), 84% (302 of 360), and 84% (330 of 393) (P = .25, P < .001, and P < .001, respectively). There were 112 false-positive interpretations at CT for 54 hilar, 16 subcarinal, 29 paratracheal, 10 subaortic, and two pulmonary ligament nodal groups and one upper paratracheal group, compared with only 58 false-positive interpretations at PET/CT for 32 hilar, seven subcarinal, 13 lower paratracheal, and six subaortic nodal groups. There were 10 false-negative interpretations at CT for four hilar, two lower paratracheal, and two subcarinal nodal groups, one prevascular and retrotracheal group, and one inferior pulmonary group, but only five false-negative interpretations at PET/CT (one each for paratracheal, subaortic, subcarinal, inferior pulmonary, and hilar nodal groups). CONCLUSION: Integrated FDG PET/CT is significantly better than stand-alone CT for lung cancer staging and provides enhanced accuracy and specificity in nodal staging.

Carcinoma, Non-Small-Cell Lung↗

Significance of cerebrospinal fluid sIL-2R level as a marker of CNS involvement in acute lymphoblastic leukemia.

Soluble IL-2 receptor (sIL-2R), total protein, uric acid, glucose, aspartate aminotransferase (AST) and lactate dehydrogenase (LD) levels were analyzed in 153 (19 cytology(+), 134 cytology(-)) pairs of CSF and serum samples and the data were compared with the results of cytologic examination to find new CSF markers of CNS involvement in 77 patients with acute lymphoblastic leukemia (ALL). The CSF leukocyte count of cytology(+) samples averaged 107.6+/-362.4 cells/microl, and was higher than that of cytology(-) samples (1.0+/-3.4 cells/microl, p=0.001). The CSF sIL2-R level of cytology(+) samples averaged 162.1+/-247.7 U/ml, and was higher than that of cytology(-) samples (11.2+/-44.6 U/ml, p <0.001). The CSF total protein, uric acid, glucose, AST, and LD levels were not significantly different in cytology(+) and cytology(-) samples (p >0.05). ROC curves showed that the discrimination power of CSF sIL2-R for the presence of leukemic blasts was better than that of CSF leukocyte counts. With a cut-off value for CSF sIL2-R at 10 U/ml, the sensitivity was 89.5% and the specificity was 89.6%. With a cut-off value for CSF leukocyte count at 4 cells/microl, the sensitivity and specificity were 47.4% and 63.2%, respectively. In conclusion, CSF sIL2-R level is a valuable marker of CNS involvement in ALL patients; a level of >10 U/ml may serve as an objective indicator of CNS involvement in conjunction with conventional cytology and the CSF leukocyte count.

Biomarkers, Tumor↗

Proteomic identification of annexins, calcium-dependent membrane binding proteins that mediate osmotic stress and abscisic acid signal transduction in Arabidopsis.

Comparative proteomic analysis of the Arabidopsis thaliana root microsomal fraction was performed to identify novel components of salt stress signaling. Among the salt-responsive microsomal proteins, two spots that increased upon salt treatment on a two-dimensional gel were identified as the same protein, designated annexin 1 (AnnAt1). Annexins comprise a multigene family of Ca2+-dependent membrane binding proteins and have been extensively studied in animal cells. AnnAt1 is strongly expressed in root but rarely in flower tissue. In this study, the results suggest that salt stress induces translocation from the cytosol to the membrane and potential turnover of existing protein. This process is blocked by EGTA treatment, implying that AnnAt1 functions in stress response are tightly associated with Ca2+. T-DNA insertion mutants of annAt1 and a different isoform, annAt4, displayed hypersensitivity to osmotic stress and abscisic acid (ABA) during germination and early seedling growth. The results collectively suggest that AnnAt1 and AnnAt4 play important roles in osmotic stress and ABA signaling in a Ca2+-dependent manner.

Abscisic Acid↗

Submuscular augmentation mammaplasty using a perinipple incision.

The periareolar approach for submuscular augmentation mammaplasty sometimes shows a widened or hypertrophic scar and distorts the shape of the areolar-skin junction. The authors describe submuscular augmentation mammaplasty using a perinipple incision and muscle preservation techniques. The perinipple incision can be extended using a backcut within the areola according to the thickness of the index finger of the operator. The authors could reach the lateral edge of the pectoralis major and lift it while preserving anatomic continuity. The folded, smooth saline implant was introduced with a no-touch or minimal-touch technique. Implant volumes ranged from 175 to 325 mL. Ten to 25-mL volume was overfilled (within the recommended amount), particularly large volume was overfilled in patients who had a thin envelope to reduce the palpation of the edge of the implant. From August 2000 to December 2002, 306 patients underwent subpectoral augmentation mammaplasty via the perinipple approach. Eleven patients complained of rippling or a visible fold. There were 7 patients who required a partial capsulectomy through the perinipple incision again. The scar was well hidden but scar revision was needed in 17 patients as a result of skin slough on the areola flap. Of these cases, some were camouflaged using a medical tattooing procedure as well. Pain was reduced markedly compared with the axillary approach. In conclusion, the perinipple incision has a less visible scar in patients who have an ill-demarcated skin-areolar junction and provides a similar operative field compared with the periareolar incision. In addition, preservation of the normal skin-areola junction is cosmetically successful.

Adult↗

The first case of intraperitoneal bronchogenic cyst in Korea mimicking a gallbladder tumor.

We present a case of an intraperitoneal bronchogenic cyst located at inferior surface of the liver, next to the gallbladder which clinically mimicked a gallbladder tumor. This is the first case reported in Korea, and we offer reviews of the related literatures. A 48-yr-old woman was admitted to our hospital because of intermittent abdominal pain in right upper quadrant. Computed tomography showed a large mass along-side the gallbladder. During laparotomy, the mass showed an ovoid cystic nature, which was attached to the normal gallbladder and liver bed. Cyst excision with cholecystectomy was performed, and histopathological examination revealed a broncho-genic cyst. Most bronchogenic cysts have a benign nature, but malignant changes have also been reported. Therefore, if a cystic tumor in the abdomen is suspected during preoperative diagnosis, a bronchogenic cyst should be considered in the differential diagnosis.

Adolescent↗

Evaluation of Vitek system for susceptibility testing of Enterococcus faecium isolates.

Although imipenem is not a first-line drug for treating enterococcal infection, it could well become a useful drug for treating mixed infections that include enterococci. However, there is no NCCLS guideline for susceptibility testing of imipenem versus enterococci. Moreover, there are no statements to indicate that in vitro susceptibility results for other antimicrobial agents can be used to predict the in vitro activity of imipenem against enterococci. In this study, 52 Enterococcus faecium isolates were collected from patients hospitalized at Kangnam St. Mary's Hospital between March 2002 and December 2002. The sources of the isolates were mainly urine specimens and wounds. For ampicillin, the "major" and "very major" error rates observed with the Vitek system were 0% and 2.0%, respectively. For penicillin, the major and very major error rates observed with the Vitek system were both 0%. For imipenem, the major and very major error rates observed with the Vitek system were 0% and 36.5%, respectively. The MICs of ampicillin and penicillin obtained using the Vitek system were reliable, but that of imipenem was unreliable. In the 52 E. faecium isolates, the in vitro activity of penicillin and ampicillin versus enterococci accurately predicted that of imipenem. Therefore, the MIC of imipenem obtained with the Vitek system must be retested by the agar dilution method, when it disagrees with those of penicillin and ampicillin.

Ampicillin↗

[The clinical study on spontaneously ruptured hepatocellular carcinoma].

BACKGROUND/AIMS: Spontaneous rupture of hepatocellular carcinoma (HCC) is known as a rare but life- threatening condition because of massive blood loss into the peritoneal cavity. In the countries with high prevalence, the reported incidence of spontaneous rupture and hemorrhage ranged from 10.2% to 14.5% of patients with HCC. This study was aimed to analyze the risk factors for spontaneous rupture and prognosis in the patients with ruptured HCC. METHODS: Among 642 consecutive patients with HCC who had admitted to Gyeongsang National University Hospital from January 1998 to September 2003, spontaneous rupture of HCC occurred in 83 patients (12.9%). The medical records of the 83 patients were reviewed retrospectively, and the clinico-laboratory parameters and radiologic findings were analyzed. RESULTS: Sixty-nine out of the 83 patients were male, the mean age was 57.7 +/- 13.2 years (male, 56.8 +/- 12.9 years; female, 62.3 +/- 13.5 years). Location of tumor, Child-Pugh class and Okuda stage were the risk factors influencing spontaneous rupture of HCC, whereas the TNM stage, presence of portal vein thrombosis, and size of the tumor were not. Among the 83 patients with ruptured HCC, 51 were treated by transarterial embolization (TAE), 31 by supportive measures, and 1 by operation. The median survival time was 3.4 +/- 4.5 months in all patients with ruptured HCC, 4.9 +/- 5.1 in successful TAE, and 2.1 +/- 3.4 in supportive measure groups. CONCLUSIONS: Advanced Child-Pugh class, advanced Okuda stage, and peripheral location were the risk factors for spontaneous rupture of HCC. The prolonged survival could be achieved in patients eligible for successful transarterial embolization rather than supportive measures.

Aged↗

Arsenic trioxide (As2O3) sensitivity of carcinoma cell lines and cancer cells from patients with carcinomatosis peritonei.

The effectiveness of As2O3 treatment was studied in 3 carcinoma cell lines, LoVo, OVCAR-3, and PA-1, and in cancer cells obtained from ascites fluids of 8 patients with carcinomatosis peritonei. LoVo, OVCAR-3, and PA-1 cell lines, and cancer cells from the patients were cultured in As2O3 gradient media; As2O3 sensitivity was evaluated by trypan blue dye exclusion and by morphologic examination after Wright staining. PA-1 was the most sensitive cell line to As2O3; OVCAR-3 and LoVo were resistant to As2O3. Cancer cells from 2 of 8 patients were sensitive to As2O3. The in vivo tumoricidal effect of As2O3 (100 microg/day, i.p.) was studied in 30 BALB/c nude mice following i.p. implantation of PA-1 tumor cells. The 17 As2O3-injected mice died of extensive intratumoral hemorrhage, necrosis, and hemorrhagic ascites within 48 hr after initial treatment. In 10 As2O3-untreated tumor-bearing control mice, only focal intratumoral hemorrhage and necrosis were noted. In summary, solid tumor cell lines and cancer cells from patients showed various As2O3 sensitivities in vitro, and As2O3 had a marked tumoricidal effect on PA-1 cells in vivo. These results suggest that As2O3 treatment might possibly be beneficial in patients with carcinomatosis peritonei who are resistant to conventional therapy and whose tumors show in vitro sensitivity to As2O3. However, to minimize the life-threatening tumor lysis effect, it would be better to administer As2O3 after removal of the peritoneal tumor masses.

Animals↗

Prognostic value of cardiac autonomic neuropathy independent and incremental to perfusion defects in patients with diabetes and suspected coronary artery disease.

We investigated the prognostic value of cardiac autonomic neuropathy (CAN) in relation to perfusion defects in 146 diabetic patients with suspected coronary artery disease. Perfusion defects and CAN were significant univariate predictors of death (p=0.05 and p<0.001, respectively) and cardiac events (p<0.001 and p<0.002, respectively). However, CAN remained a significant predictor of death and cardiac events after adjustment for perfusion defects (both p<0.02), and provided prognostic information incremental to that offered by perfusion defects alone (p<0.003 and p<0.006, respectively).

Age Factors↗

CD99 type II is a determining factor for the differentiation of primitive neuroectodermal cells.

CD99 is a 32-kDa cell surface molecule present on thymocytes, peripheral T cells, many other hematopoietic stem cells and somatic cells were implicated in cell-cell adhesion and cell-activation phenomena. Two major subtypes have been identified so far, designated CD99 type I and type II. We have investigated the correlation between the degree of neural differentiation and the expression of CD99 subtypes in three differentially differentiated cell lines such as CADO-ES1, RD-ES, and SH-N-SY5Y, in order of differentiation. In addition, we induced differentiation of the RD-ES cell line by N6,2'-dibutyryl-cAMP (db-cAMP). Six days after treatment with db-cAMP, RD-ES cell line has changed its morphology from uniform round cells to cells with neurites, and initially CD99 type II-overexpressed RD-ES cells showed significant down-regulation of CD99 type II, whereas CD99 type I expression remained constant. When RD- ES cells were transfected with the cDNA encoding for CD99 type I-green fluorescence protein (GFP) and type II-GFP, CD99 type II transfected RD-ES cell line remained unchanged with morphology of undifferentiated form. Our data suggest that CD99 type II acts as a negative regulator in the neural differentiation of precursor cells that might occur during nerve system development.

12E7 Antigen↗

Preexisting intimal hyperplasia of radial artery is associated with early failure of radiocephalic arteriovenous fistula in hemodialysis patients.

BACKGROUND: The radiocephalic arteriovenous fistula (AVF), which provides the best vascular access for hemodialysis, continues to have a high incidence of early failure. Intimal hyperplasia (IH) of the radial artery is observed commonly in uremic patients before hemodialysis, but the impact of this preexisting IH on the early failure of radiocephalic AVFs has not been reported yet. Therefore, we designed this study to: (1) investigate clinical risk factors for IH, and (2) determine whether preexisting IH of the radial artery is associated with early failure of a radiocephalic AVF. METHODS: Specimens from the radial artery were obtained during the radiocephalic AVF operation. IH was measured with trichrome staining, and AVF patency was prospectively followed up for 12 months after the operation. RESULTS: Of the 59 patients, 45 patients had evidence of IH in their radial artery (76.2%). Patients with IH (n = 45) were older than those without IH (n = 14; 58 +/- 12 versus 44 +/- 17 years; P = 0.003). The incidence of diabetes mellitus in patients with IH was greater than that in patients without IH (60.0% versus 28.6%; P = 0.004). Of the 57 patients, except for 2 patients who died before the end point of the study with patent AVFs, fistula failure was observed only in patients with IH (22 of 44 patients; 50% versus 0%; P < 0.001). The intima was thicker in the failed-AVF group than the patent-AVF group (93.1 +/- 37.5 versus 45.6 +/- 17.4 micrometer P < 0.001). CONCLUSION: This study suggests that early failure of radiocephalic AVFs in hemodialysis patients is closely associated with preexisting IH of the radial artery.

Adult↗

Creating alignment and anisotropy in engineered heart tissue: role of boundary conditions in a model three-dimensional culture system.

Electrical and mechanical anisotropy arise from matrix and cellular alignment in native myocardium. Generation of anisotropy in engineered heart tissue will be required to match native properties and will provide immediate opportunities to investigate the genesis and structural determinants of functional anisotropy. We investigated the influence of geometry and boundary conditions on fibroblast alignment in thin collagen gels. Consistent with previous reports, we found that human dermal fibroblasts align parallel to free edges in partially constrained gels; in contrast to at least one report, fibroblasts in fully constrained gels remained randomly aligned independent of geometry. These experiments allowed us to distinguish between two possible mechanisms for such alignment. Mean orientations that followed the shape of the free edges and stronger alignment nearest the free edges in gels with a variety of geometries suggested that cells align parallel to a local free boundary rather than to local lines of tension. These findings focus attention on the presence of voids and free surfaces such as the endocardium and epicardium, cleavage planes, and blood vessels in governing cell and fiber alignment in developing and remodeling myocardium, myocardial scar tissue, and engineered heart constructs.

Anisotropy↗

[A clinical and immunohistochemical study on gastrointestinal stromal tumor].

BACKGROUND/AIMS: As the relationship between gastrointestinal stromal tumors (GIST) and interstitial cells of Cajal had become clear, GIST is defined as CD117 positive mesenchymal tumors, and recognized as a new distinct entity among mesenchymal tumors presenting as gastrointestinal submucosal tumors (SMT). To evaluate GISTs in the category of SMTs, we analyzed mesenchymal SMTs immunohistochemically and clinicopathologically. METHODS: Forty-five patients with mesenchymal SMTs, who received surgical or endoscopic resection were retrospectively analyzed for clinical parameters. Immunohistochemical staining for CD117, CD34, NSE, SMA, and S-100 was also performed. RESULTS: Among 45 tumors, 41 (91.1%) expressed CD117 and were diagnosed as GIST. The most frequent location was the gastric body. Except esophageal location (73.3%), GISTs accounted for 100% of SMTs in the gastrointestinal tract. The mixed myoid-neural differentiated type and the spindle cell shape were most common. Metastasis was observed in 5 patients (11%). All of them had tumors larger than 5 cm and died. Their mean survival was 4.6 months. CONCLUSIONS: GIST accounted for majority (91.1%) of SMTs. The presence of metastasis and tumor size at the time of diagnosis indicate poor prognostic factors. Immunohistochemical study is necessary for exact diagnosis of GIST.

Adult↗

Long-lived charge-separation by retarding reverse flow of charge-balancing cation and zeolite-encapsulated Ru(bpy)(3)(2+) as photosensitized electron pump from zeolite framework to externally placed viologen.

K(+)-exchanged, Ru(bpy)(3)(2+)-encapsulating zeolite-Y [K(+)-Ru(bpy)(3)(2+)Y] and N-[3-(dicyclohexylmethyl)oxypropyl-N'-methyl-4,4'-bipyridinium [DCH-MV(2+)] were prepared, and visible light-induced electron transfer from the zeolite-encapsulated Ru(II) complex to the size-excluded viologen was studied in acetonitrile. Addition of a series of crown ethers (CEs) into the heterogeneous solution leads to over a 10-fold increase in the yield of DCH-MV(*)(+), where the yield linearly increases as the formation constant of CE with K(+) [K(f)(K(+))(CE)] increases. The following two sequential events are attributed to be responsible for the above novel phenomenon. First, K(+) ions are liberated from the zeolite to solution during interfacial electron transfer from the photoexcited Ru(II) complexes to DCH-MV(2+). Second, the liberated K(+) ions form strong host-guest complexes with the added CE molecules, which leads to retardation of the reverse flow of the cations, hence the charge-balancing electrons, from the solution to the zeolite. Surprisingly, the yield of DCH-MV(*)(+) reaches more than approximately 50 times the amount of Ru(bpy)(3)(2+) situated in the outermost supercages, despite the absence of electron relay in the zeolite. This is attributed to photosensitized electron pumping from the zeolite framework to viologen by the outermost Ru(bpy)(3)(2+) ions. In support of the above conclusion, Ru(bpy)(3)(3+) does not accumulate in the zeolite host while DCH-MV(*)(+) accumulates in the supernatant solution. Consistent with the above, the independently prepared hexafluorophosphate salt of Ru(bpy)(3)(3+) is reduced to Ru(bpy)(3)(2+) in acetonitrile upon contact with Ru(bpy)(3)(2+)-free M(+)Y (M(+) = Li(+), Na(+), K(+), Rb(+), and Cs(+)), where the yield increases as the donor strength of the framework oxygen increases. Although small, thermal electron transfer also takes place from the zeolite framework to DCH-MV(2+), where the yield increases upon increasing the donor strength of the framework, concentration of DCH-MV(2+), temperature, and K(f)(K(+))(CE) (when K(+)Y is the zeolite host). The photoyield is always higher than the thermal yield by 4-30 times, confirming that the zeolite-encapsulated Ru(bpy)(3)(2+) serves as the photosensitized electron pump.

Journal Article↗