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Biomedical subjects

S Kim

Publications and source records attributed to S Kim.

At least 37 records · Page 2Linked to original sources

Magnifying gastroendoscopy for diagnosis of histologic gastritis in the gastric antrum.

BACKGROUND: We investigated the potential of magnifying endoscopy for diagnosis of histologic gastritis in the gastric antrum. In addition, we investigated whether magnifying endoscopy can be applied for evaluation of Helicobacter pylori eradication therapy. METHODS: We examined 176 Japanese patients including 53 with H. pylori eradication. We evaluated the antrum by magnifying observation and ordinary endoscopic findings, and compared these results. Biopsy specimens were taken from the sites observed. RESULTS: The magnified views were classified into four types. Histology of the biopsy specimens allowed us to match the four magnified views with normal mucosa with fundic glands, normal mucosa with pyloric glands, mucosa with gastritis and intestinal metaplasia/epithelial hyperplasia. The types of magnifying appearances were specific enough for the diagnosis of histologic gastritis (148 out of the 176 (82.4%) cases; sensitivity, 96.3%; specificity, 73.7%). We could accurately diagnose the histologic gastritis by magnifying endoscopy in 49 out of the 53 (92%) cases with H. pylori eradication, while only in 38% by ordinary endoscopy. The accuracy of diagnosis was statistically higher with the use of magnifying endoscopy than with ordinary endoscope (P < 0.001). CONCLUSION: Magnifying gastroendoscopy is useful to judge the histologic gastritis, especially, in cases with H. pylori eradication.

Adult↗

Incidence and risk factors of renal dysfunction after liver transplantation in Korea.

Renal dysfunction, one of the most common complications after liver transplantation, influences patient outcomes. Little is known, however, about it in Korea. The aims of this study were to determine the incidence and to identify the risk factors for renal dysfunction after liver transplantation. Sixty-two patients who survived over 6 months after transplantation were enrolled. Renal function was classified by creatinine clearance (Ccr, mL/min), which was estimated using the Cockcroft-Gault formula. Twenty-seven patients (44%) showed mild renal dysfunction (60 < or = Ccr < 90), and 27 patients (44%), moderate dysfunction (30 < or = Ccr < 60). The others were found to have normal function (Ccr > or = 90). None displayed severe dysfunction (Ccr < 30). Compared to a control group (Ccr > or = 60), the renal dysfunction group showed lower preoperative Ccr (91 +/- 28.6, 63 +/- 21.9, respectively, P < .01) and lower Ccr at 3 months after transplantation (72 +/- 17.1, 49 +/- 14.6, respectively, P < .05). Age, sex, immunosuppressive drug usage, serum tacrolimus levels, and the frequency of postoperative acute renal failure did not affect the postoperative renal dysfunction. Twenty-six patients received mycophenolate mofetil while reducing the dose of calcineurin inhibitors because of compromised renal function. With mycophenolate mofetil treatment, the renal function seemed to improve, although the difference was not statistically significant (P = .057). These data demonstrate that renal dysfunction is common after liver transplantation and that preoperative renal function is the important factor predicting postoperative renal dysfunction.

Adolescent↗

Failure of trilineage blood cell reconstitution after initial neutrophil engraftment in patients undergoing allogeneic hematopoietic cell transplantation - frequency and outcomes.

The outcomes of patients who experience the failure to reconstitute a trilineage of blood cells after initial neutrophil engraftment were evaluated in 178 patients with hematologic disorders, who underwent allogeneic HCT. Of 165 qualified patients (five with primary engraftment failure; eight deaths before day 60 of HCT), 43 (26%) satisfied the criteria for the initial (n=22; failure of platelet >20 000/microl or red blood cell transfusion independence/reticulocyte count >/=1.0% by day 60) or subsequent (n=21, ANC <500/microl for >/=3 days, platelet <20 000/microl for >/=7 days, or red blood cells transfusion/reticulocyte <1.0% after initial trilineage reconstitution) failure. GVHD was the most common clinical condition associated with cytopenia (n=24). In all, 20 patients (47%) recovered at least partially with a median of 52 days (range 8-323) later, with 12 of those 20 patients recovering completely. The eventual reconstitution failure rate was 14% (23/163 patients). The number of cell lineages involved in the cytopenia was the only independent variable that predicted partial recovery (1 lineage vs 2-3 lineages with odds ratio of 8.69 (95% CI 1.96-38.60), P=0.004). Five/20 patients with vs 20/23 patients without partial recovery died. Trilineage reconstitution failures after allogeneic HCT need systematic analysis in the future studies.

Adolescent↗

Lymphocyte recovery as a positive predictor of prolonged survival after autologous peripheral blood stem cell transplantation in T-cell non-Hodgkin's lymphoma.

We performed a retrospective study on recovery and survival of patients with T-cell NHL after autologous peripheral blood stem cell transplantation (APBSCT). Of a total of 39 patients with high-risk T-cell NHL, 33 were analyzed. Six patients who experienced early treatment mortality without full lymphocyte recovery were excluded. We chose absolute lymphocyte count (ALC) recovery as 1000 cells/microl as a cutoff value. ALC recovery day was defined as the first of 3 consecutive days with ALC above 1000 cells/microl. Univariate analysis revealed that age younger than 45 years, good international prognostic index, chemosensitive disease prior to APBSCT, and early ALC recovery (1000 cells/microl within 25 days of APBSCT) were predictors of prolonged survival. Multivariate analyses confirmed that chemosensitive disease prior to APBSCT and early ALC recovery were strongly associated with better overall survival (OS) (P=0.005 and 0.011, respectively) and progression-free survival (PFS) (P<0.001 and P=0.013, respectively). Our finding, that ALC recovery > or =1000 cells/microl is an independent predictor of OS and PFS in T-cell NHL after APBSCT, suggests that earlier immune recovery may contribute to longer survival.

Adolescent↗

Cyclosporine alone vs cyclosporine plus methotrexate for post-transplant immunosuppression after HLA-identical sibling bone marrow transplantation: a randomized prospective study.

The role of methotrexate (MTX), given with cyclosporine (CS), after HLA-identical sibling bone marrow transplantation needs to be defined. In all, 80 patients with hematologic malignancies were enrolled in a prospective randomized trial. All were given BuCy conditioning. The 40 patients in the CS arm received CS 3 mg/kg/day intravenously, with subsequent oral dosing. Patients in the CS + MTX arm received, in addition to CS, MTX intravenously, 15 mg/m2 on day 1, and 10 mg/m2 on days 3, 6, and 11. Transplantation-related mortality was low in both groups of patients (13 vs 11% for CS vs CS + MTX groups, P = 0.94). The CS group had a significantly higher frequency of chronic graft-versus-host disease (56 vs 32%, P = 0.05). After a median follow-up of 22.1 months (5.1-47.8 months), three of 30 vs 10 of 28 patients with acute leukemia/myelodysplastic syndrome (MDS) in CS group vs CS + MTX group relapsed (P = 0.01) yielding better overall survival for patients with acute leukemia/MDS treated with CS (P = 0.02). After HLA-identical sibling bone marrow transplantation, immunosuppression with CS, with or without MTX, resulted in similarly low transplantation-related mortality. In acute leukemia/MDS, decreased relapse with patient survival prolongation was observed in the CS group.

Acute Disease↗

Engineering the splice acceptor for improved gene expression and viral titer in an MLV-based retroviral vector.

We have recently developed a retroviral vector that contains a splice acceptor from the human EF1-alpha gene and drives a significantly higher level of gene expression than other well known murine leukemia virus-based vectors. However, one downside of this vector is that viral titer significantly varies depending on the packaging lines used. Results from Northern blot analysis indicated that in certain cell lines the genomic transcript containing the packaging signal sequence was too efficiently spliced to the subgenomic RNA, resulting in low levels of genomic RNA and thus leading to a low viral titer. We tested the possibility of overcoming this problem by introducing mutations around the splice acceptor sequence in such a way that a delicate balance was maintained between the splicing efficiency (which determines the level of gene expression) and the amount of genomic transcript (which influences viral titer). After mutational analysis, one such mutant was found to meet this requirement. The newly constructed vector containing the engineered splice acceptor could indeed drive higher levels of expression in many therapeutic genes than other control vectors, without significantly compromising viral titer.

Base Sequence↗

Dominant-negative mutant of c-Jun gene transfer: a novel therapeutic strategy for colorectal cancer.

Activator protein-1 (AP-1), a transcription factor, is activated through many oncogenic signals. However, its biological role in colorectal cancer has not been fully elucidated. To investigate the role of AP-1 in colorectal cancer, we constructed an adenovirus-expressing TAM67, a dominant-negative mutant of c-Jun lacking the transactivation domain of wild c-Jun (DN-c-Jun), to inhibit endogenous AP-1. AP-1 DNA-binding activity was increased in colon cancer cells (HT-29 cells) by serum stimulation, followed by an increase in both [(3)H]thymidine incorporation and cell number. Transfection of Ad-DN-c-Jun to HT-29 cells significantly inhibited serum-induced cell proliferation in vitro. As shown by flow cytometric analysis, DN-c-Jun significantly inhibited entrance into S phase after serum stimulation, thereby leading to G(1) arrest. In vivo transfection of Ad-DN-c-Jun into xenografted HT-29 cell tumors in nude mice significantly decreased tumor volume on day 21 after treatment. A change was associated with decrease in Ki-67 labeling index. These observations together showed that AP-1 is a critical modulator for proliferation and cell cycle of HT-29 cells. We obtained the first evidence that DN-c-Jun gene transfer exerted a significant antitumor effect on colon cancer both in vitro and in vivo. DN-c-Jun gene transfer may be a new candidate for treatment of colorectal cancer.

Animals↗

Viral vector-mediated transduction of a modified thrombospondin-2 cDNA inhibits tumor growth and angiogenesis.

Gene therapy represents a possible alternative to the chronic delivery of recombinant antiangiogenic proteins to cancer patients. We have constructed retroviral and adenoviral vectors that express murine N-terminal fragments of thrombospondin-2 (NfTSP2), a potent endogenous inhibitor of tumor growth and angiogenesis. To test the possibility of anticancer gene therapy using NfTSP2, we tested whether an ex vivo retrovirus-mediated procedure could be used for the treatment of tumors. The treatment of tumor-bearing mice with syngenic immortalized cell lines expressing NfTSP2 led to a tumor volume reduction up to 70% as compared with the controls (P<0.005). In addition, the established tumors were eradicated in 40% of the mice treated with NfTSP2-expressing cells. Furthermore, the intratumoral injection of the NfTSP2-expressing adenoviral vector to the human squamous cell carcinoma in nude mice resulted in a significant reduction of the growth rates and the volumes of the carcinoma (P<0.05). Immunohistochemical staining of the tumors indicated that the total area and the average size of tumor vessels were significantly reduced in the treatment group versus the controls (P<0.05). In conclusion, the present study clearly demonstrates that the viral vector-mediated transfer of the NfTSP2 gene could inhibit the growth of tumors by perturbing tumor-associated angiogenesis.

Adenoviridae↗

Treatment of relapsed acute myeloid leukemia after allogeneic bone marrow transplantation with chemotherapy followed by G-CSF-primed donor leukocyte infusion: a high incidence of isolated extramedullary relapse.

For patients with acute myeloid leukemia (AML) relapsed after allogeneic bone marrow transplantation (BMT), donor leukocyte infusion (DLI) as sole therapy has very limited efficacy. We tested the effects of cytoreductive chemotherapy, followed immediately by G-CSF-primed DLI (chemotherapy followed by DLI, Chemo-DLI), in 16 AML patients who relapsed after allogeneic BMT. In all, 10 of these patients achieved complete remission (CR), four of whom remain alive in CR at a median follow-up of 1488 days after DLI. The 2-year overall survival (OS) for the entire cohort was 31%. The 1-year OS for patients with post-BMT remission of 6 months or longer was 55%, compared with 0% for patients with post-BMT remission of less than 6 months, making post-BMT remission duration the only significant prognostic factor for OS (P=0.015). These findings suggest that Chemo-DLI could induce durable remissions in a proportion of relapsed AML patients with relatively long post-BMT remission duration. All five patients who relapsed after achieving CR with Chemo-DLI relapsed at extramedullary sites in the presence of continuous bone marrow remission, suggesting uneven graft-versus-leukemia effects in different parts of the body. Although our data should be interpreted cautiously considering the limited number of patients, isolated extramedullary relapse seems to be common after Chemo-DLI.

Acute Disease↗

Relationship between serum testosterone and activities of testicular enzymes after continuous and intermittent training in male rats.

To gain more information on the effects of training types on testosterone secretion, the present study investigated the relationship between serum testosterone (ST) and the activities of oxydoreductive enzymes in Leydig cells to continuous and intermittent training regimes. Male rats swam with a load of 3.5 % body weight for 90 min in the continuous training group, and 15 min separated by a 7-min rest interval x 6 times in the intermittent training group, 6 days per week for 5 weeks. ST were measured immediately and 24 h after exercise, and the activities of SDH, LDH and G6PDH in Leydig cells were measured 24 h after exercise, following 5 weeks of training. It was found that ST declined following continuous (0.54 +/- 0.32 nmol/l) and intermittent (1.64 +/- 1.80 nmol/l) exercise compared to sedentary group (9.55 +/- 5.17 nmol/l). This diminishing effect on ST was still significant 24 h after continuous exercise (5.96 +/- 2.79 nmol/l), not after intermittent exercise (7.41 +/- 4.77 nmol/l). The activities of SDH and LDH increased, whereas G6PDH decreased in Leydig cells, after both continuous and intermittent training. SDH and G6PDH showed the high activities in the intermittent training group relative to continuous training group. These differences in the activities of SDH and G6PDH might be considered as the possible causes for ST responses to training types.

Animals↗

Isolation and characterization of Lactobacillus species inhibiting the formation of Streptococcus mutans biofilm.

Oral bacterium S11 was isolated from the saliva of young children without dental caries and with little or no visible supragingival plaque. The S11 strain showed 99.5% similarity with Lactobacillus fermentum, and was identified on the basis of biochemical characteristics and a 16S rDNA sequence. S11 strain and its culture supernatant significantly inhibited the formation of the insoluble glucan produced by Streptococcus mutans Ingbritt. S11 did not affect the multiplication of S. mutans Ingbritt, but the adherence of S. mutans Ingbritt onto cuvette walls was inhibited completely.

Antibiosis↗

Exercise and myocardial tolerance to ischaemia-reperfusion.

UNLABELLED: It is well established that both short-term (1-5 days) and long-term (weeks to months) high intensity exercise (i.e. 70-75%VO2max) provides cardioprotection against ischaemia-reperfusion injury. However, it is unclear if moderate intensity exercise will also provide cardioprotection. AIM: Therefore, these experiments compared the protective effects of moderate vs. high intensity exercise in providing defense against ischaemia-reperfusion injury. METHODS: Male Sprague-Dawley rats were randomly assigned to one of three-experimental groups: (1) sedentary (control); (2) moderate intensity treadmill exercise (60 min day(-1) at approximately 55%VO2max); or (3) high intensity treadmill exercise (60 min day(-1) at approximately 75%VO2max). Hearts were exposed to 20 min of global ischaemia followed by 30 min reperfusion in an isolated working heart preparation. RESULTS: Compared with sedentary rats, both moderate and high intensity exercised rats maintained a higher (P < 0.05) percentage of pre-ischaemia cardiac output and cardiac work (cardiac output x systolic blood pressure) during reperfusion. No differences in the percent recovery of cardiac output and heart work existed (P > 0.05) between the two exercise groups. CONCLUSIONS: These data reveal that both moderate and high intensity exercise training provide equivalent protection against ischaemia-reperfusion injury.

Animals↗

Correlation of MAP kinases with COX-2 induction differs between MKN45 and HT29 cells.

BACKGROUND: Mitogen-activated protein (MAP) kinases, including extracellular signal-regulated kinases (ERK),c-Jun NH2-terminal kinases (JNK) and p38 MAP kinase (p38 MAPK) are important intermediates of the signal-transduction pathway from the cell surface to the nucleus. Expression of cyclooxygenase (COX)-2, associated with proliferation, apoptosis or both of gastrointestinal cancer cells, is mediated through MAP kinase families. However, the correlation between respective MAP kinase signals and COX-2 in the proliferation of gastric and colon cancer cells has not been well elucidated. AIM: We examined the effect of selective inhibitors of MAP kinases and COX-2 on serum-induced proliferation of gastric (MKN45) and colon (HT29) cancer cells. METHODS: After 24-h serum starvation, cancer cells were stimulated with 2% serum and COX-2 inhibitors (NS398 10 micromol/L, or etodolac 100 micromol/L) or 1 h after preincubation with inhibitors for ERK (PD98059 20 micromol/L) or p38 MAPK (SB203580 10 micromol/L). Phosphorylated MAP kinases and COX-2 protein were evaluated by Western blotting, and the proliferation of cancer cells was estimated by 3H-thymidine incorporation. Transcription factors nuclear factor-kappaB and CREB were assayed by an electorophoretic mobility shift assay. RESULTS: Serum increased the proliferation of MKN45 and HT29 cells by 280% and 200%, respectively, compared with the control levels (100%). In both cancer cells, phosphorylated MAP kinases were increased within 30 min after stimulation. PD98059 and SB203580 inhibited the serum-induced proliferation of MKN45 by 21% and 51% and of HT29 by 81% and 69%, respectively. NS398 and etodolac inhibited the proliferation of HT29 by 21% and 41%, respectively, but not that of MKN45. PD98059 and SB203580 also suppressed serum-induced expression of COX-2 protein in HT29 cells. In addition to the activation of MAP kinases and COX-2, activities of nuclear factor-kappaB and CREB were also increased during HT29 cell proliferation. CONCLUSIONS: These results suggest that the correlation of MAP kinases with COX-2 induction for cell proliferation differs between MKN45 and HT29 cells.

Blotting, Western↗

Characteristics of intramucosal gastric carcinoma with lymph node metastatic disease.

AIM: Recent trends in treatment strategy for early gastric cancer (EGC) are towards minimal surgical procedures, such as endoscopic mucosal resection and laparoscopic partial resection. There is a possibility of incomplete removal of regional lymph nodes in minimal procedures, which may subsequently decrease the chance of a cure. Therefore, it is essential to be able to predict lymph node status and to make careful selection of candidates for mucosal resection. METHODS AND RESULTS: We studied the relationship between lymph node status and various pathological parameters including macroscopic appearance, location, size, differentiation, presence of ulceration, vascularity, presence of gastritis cystica profunda-like glandular proliferation, disruption of the muscularis mucosae and invasion into the muscularis mucosae, using age- and sex-matched samples of 40 node-positive and 80 node-negative tumours to define the characteristics of intramucosal EGCs. Histological differentiation (P < 0.001), increased submucosal vascularity (P < 0.05), breakdown of the muscularis mucosae (P < 0.05), and invasion of tumour cells into the muscularis mucosae (P < 0.05) were correlated with the lymph node status of intramucosal gastric carcinoma. Furthermore, diffuse type histology (P < 0.001) and deep invasion into the muscularis mucosae (P < 0.05) were indicators of node-positive intramucosal EGCs. CONCLUSIONS: These histological indicators are easily accessible and seem to predict lymph node metastatic disease in limited surgical specimens. Patients should be carefully selected despite the recent trend toward less invasive resection of EGCs, especially for those apparently confined to the mucosa.

Adult↗

Comparison of apical transportation between ProFile and ProTaper NiTi rotary instruments.

AIM: To use a newly developed radiographic technique to compare apical transportation and loss of working length (WL) between.06 taper ProFile Series 29 and ProTaper nickel-titanium (NiTi) rotary instruments in vitro. METHODOLOGY: Mesio-buccal canals of 40 extracted mandibular molars were randomly divided into two groups. Group 1 was instrumented with ProFile and group 2 with ProTaper instruments according to the manufacturers' directions. A specially constructed radiographic jig with a Schick digital radiographic system (Schick Technologies Inc., Long Island City, NY, USA) was used to take pre- and postoperative radiographs of the samples at predetermined angulations. Using AutoCAD 2000 (Autodesk Inc., San Rafael, CA, USA), the central axes of initial and final instruments were radiographically superimposed to determine the loss of WL and degree of transportation at D(0), D(1), D(2) and D(4) from the WL. Data were analysed using repeated-measures anova. RESULTS: A statistically significant difference in apical transportation was found at the D(4) level between the two groups (P = 0.05). There was no statistical significance regarding postinstrumentation change in WL between groups. Spearman's Bivariate Correlation analysis indicated no statistically significant relationship between the radius of curvature and transportation. CONCLUSION: The results indicate that both ProTaper and ProFile instruments are comparable to each other in regards to their ability to optimally enlarge root canal with minimal transportation and loss of WL in vitro.

Dental Alloys↗

Antibacterial effect of crude water-soluble arrowroot (Puerariae radix) tea extracts on food-borne pathogens in liquid medium.

AIMS: To evaluate the effect of crude water-soluble arrowroot tea extracts on microbial growth of food-borne pathogens in liquid medium and to confirm the damage to bacterial cells using Transmission Electronic Microscopy (TEM). METHODS AND RESULTS: Inhibition of growth of Escherichia coli O157:H7, Salmonella enterica serovar Enteritidis, Listeria monocytogenes and Staphylococcus aureus was investigated using Brain Heart Infusion (BHI) broth containing 0 (control), 0.63, 1.25, 2.5 and 5.0% (w/v) arrowroot tea. Bacterial cell counts were performed on specific selective agar on days 0, 1, 3 and 5. BHI containing 5.0% arrowroot tea extract showed a 6-7 log suppression of growth for all test strains on days 3 and 5, compared with the control. Even 0.63% arrowroot tea effectively inhibited microbial growth of all test strains on day 5. TEM images of the samples treated with 5.0% arrowroot tea revealed the rupture of cell walls and nonhomogeneous disposition of cytoplasmic materials within treated bacteria. CONCLUSIONS: Crude water-soluble arrowroot tea extract strongly inhibited microbial growth of all test pathogens in liquid medium. SIGNIFICANCE AND IMPACT OF THE STUDY: Water-soluble arrowroot tea extract has the potential to be used directly on foods or as a spray on the surfaces of food handling and processing facilities in order to prevent microbial growth of both Gram-negative and Gram-positive bacteria.

Anti-Bacterial Agents↗

Different G protein-coupled signaling pathways are involved in alpha granule release from human platelets.

Alpha granule release plays an important role in propagating a hemostatic response upon platelet activation. We evaluated the ability of various agonists to cause alpha granule release in platelets. Alpha granule release was measured by determining P-selectin surface expression in aspirin-treated washed platelets. ADP-induced P-selectin expression was inhibited both by MRS 2179 (a P2Y1 selective antagonist) and AR-C69931MX (a P2Y12 selective antagonist), suggesting a role for both Galpha(q) and Galpha(i) pathways in ADP-mediated alpha granule release. Consistent with these observations, the combination of serotonin (a Galpha(q) pathway stimulator) and epinephrine (a Galpha(z) pathway stimulator) also caused alpha granule release. Furthermore, U46619-induced P-selectin expression was unaffected by MRS 2179 but was dramatically inhibited by AR-C69931, indicating a dominant role for P2Y12 in U46619-mediated alpha granule release. Additionally, the Galpha(12/13)-stimulating peptide YFLLRNP potentiated alpha granule secretion in combination with either ADP or serotonin/epinephrine costimulation but was unable to induce secretion by itself. Finally, costimulation of the Galpha(i) and Galpha(12/13) pathways resulted in a significant dose-dependent increase in alpha granule release. We conclude that ADP-induced alpha granule release in aspirin-treated platelets occurs through costimulation of Galpha(q) and Galpha(i) signaling pathways. The P2Y12 receptor plays an important role in thromboxane A(2)-mediated alpha granule release, and furthermore activation of Galpha(12/13) and Galpha(q) signaling pathway can cause alpha granule release.

Adenosine Diphosphate↗