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Biomedical subjects

S I Kim

Publications and source records attributed to S I Kim.

At least 73 records · Page 4Linked to original sources

Antibacterial properties and partial cDNA sequences of cecropin-like antibacterial peptides from the common cutworm, Spodoptera litura.

The antibacterial properties and cDNA sequences of two types of antibacterial peptides from the haemolymph of immunized common cutworm, Spodoptera litura larvae, were determined. Since the primary structures of peptides deduced from cDNA sequences showed significant homologies to cecropins A and B, they were named as Spodoptera cecropins A and B. Spodoptera cecropins were broadly effective against Gram-positive and negative bacteria. They also retained antibacterial activities in all conditions tested (at pH 5.6-8.0 and in the presence of 50-150 mM NaCl) that was adapted to confirm the antibacterial properties of Spodoptera cecropins. These results indicate that the change of pH and the increase of salt concentration in the media do not influence the activities of Spodoptera cecropins. For the reverse transcription (RT)-polymerase chain reaction (PCR) to obtain the complete primary sequence, the primer designed according to the conserved region of the cecropin leader sequences was used, which was determined by the comparison of the cDNA sequences of known cecropins. The results from RT-PCR presented that the partial cDNAs of Spodoptera cecropins A and B encode 57 and 58 amino acids, including the sequences of mature peptides, respectively. In addition, Northern blot analysis with (32)P-labeled PCR product coding for Spodoptera cecropin A revealed that Spodoptera cecropin genes are expressed in immunized fat body, but not in normal fat body.

Amino Acid Sequence↗

T-DNA insertional mutagenesis for functional genomics in rice.

We have produced 22 090 primary transgenic rice plants that carry a T-DNA insertion, which has resulted in 18 358 fertile lines. Genomic DNA gel-blot and PCR analyses have shown that approximately 65% of the population contains more than one copy of the inserted T-DNA. Hygromycin resistance tests revealed that transgenic plants contain an average of 1.4 loci of T-DNA inserts. Therefore, it can be estimated that approximately 25 700 taggings have been generated. The binary vector used in the insertion contained the promoterless beta-glucuronidase (GUS) reporter gene with an intron and multiple splicing donors and acceptors immediately next to the right border. Therefore, this gene trap vector is able to detect a gene fusion between GUS and an endogenous gene, which is tagged by T-DNA. Histochemical GUS assays were carried out in the leaves and roots from 5353 lines, mature flowers from 7026 lines, and developing seeds from 1948 lines. The data revealed that 1.6-2.1% of tested organs were GUS-positive in the tested organs, and that their GUS expression patterns were organ- or tissue-specific or ubiquitous in all parts of the plant. The large population of T-DNA-tagged lines will be useful for identifying insertional mutants in various genes and for discovering new genes in rice.

Base Sequence↗

Effect of lovastatin on small GTP binding proteins and on TGF-beta1 and fibronectin expression.

We have shown that lovastatin, an inhibitor of 3 hydroxy-3-methylglutary coenzyme A (HMG CoA) reductase, delays development and progression of diabetic nephropathy in streptozotocine-induced diabetic rats through suppression of glomerular transforming growth factor (TGF)-beta1 mRNA expression. We have also shown that lovastatin suppresses both control and high glucose (HG)-induced TGF-beta1 and fibronectin mRNA expression and protein synthesis by rat mesangial cell (RMC) and that this down-regulation by lovastatin is reversed by mevalonate. It was postulated that this down-regulation may be linked to signaling of small guanine triphosphate (GTP)-binding proteins and mediated by the limitation of isoprenoids such as farnesylpyrophosphate (FPP) and geranylgeranylpyrophosphate (GGPP) in RMC. To determine the isoprenoid and small GTP-binding proteins involved in TGF-beta1 and fibronectin expression. FPP or GGPP was added alone or in combination to RMC treated with lovastatin cultured under normal or high glucose condition. Suppression of TGF-beta1 and fibronectin expression by lovastatin was reversed effectively when GGPP was added alone. Partial reversal of lovastatin effect on fibronectin and TGF-beta1 expression was found when FPP was added alone. Adding both GGPP and FPP resulted in complete reversal of lovastatin effect on fibronectin but not TGF-beta1 suggesting that fibronectin and TGF-beta1 are regulated differently. Furthermore, luciferase activity of RMC cotransfected with fibronectin promoter reporter system and plasmid-expressing C3 exoenzyme (a specific inactivator of Rho family GTP binding proteins, pEFC3) was completely suppressed when compared with RMC cotransfected with empty vector, pEF. Because geranylgeranylation is usually involved in post-translational modification and membrane targeting of Rho family small GTP binding proteins, these data indicate that Rho family small GTP-binding proteins rather than Ras family small GTP binding proteins may play a key role in the TGF-beta1 and fibronectin expression in RMC.

Animals↗

Prevention of postoperative nausea and vomiting by continuous infusion of subhypnotic propofol in female patients receiving intravenous patient-controlled analgesia.

In this prospective, randomized, double-blind, placebo-controlled study, the use of continuous subhypnotic propofol infusion as an antiemetic in fentanyl intravenous patient-controlled analgesia (i.v. PCA) was investigated during the first 24 h after surgery. One hundred female patients, ASA I-II, aged 20-71 yr, undergoing major gynaecological or orthopaedic surgery, were included. Either propofol 10 mg or placebo (1 ml of Intralipid) was given and one of the following five regimens was maintained for 24 h: propofol 5, 10, 15 or 20 microg kg(-1) min(-1) or Intralipid 1 ml h(-1) as a placebo. Fentanyl i.v. PCA was started in the postanaesthesia care unit for postoperative analgesia. Significantly more of the patients given propofol 15 and 20 microg kg(-1) min(-1) experienced no nausea or vomiting compared with those given placebo (65% and 70% versus 25%; P<0.05). Patients given propofol 20 microg kg(-1) min(-1) reported more sedation than those in the other groups 4 h after surgery (P<0.05).

Adult↗

Polymerase chain reaction detection of Mycobacterium tuberculosis from fine-needle aspirate for the diagnosis of cervical tuberculous lymphadenitis.

BACKGROUND: Despite its well-established usefulness in the diagnosis of cervical tuberculous lymphadenitis, fine-needle aspiration cytology (FNAC) has several limitations in its clinical applications, especially when the presence of acid-fast bacilli is not proven. Furthermore, fine-needle aspirate is sometimes inadequate for diagnosis, and the sensitivity and specificity of this technique for cervical tuberculous lymphadenitis has not been firmly established. OBJECTIVE: The authors performed Mycobacterium tuberculosis polymerase chain reaction (PCR) for mycobacterial DNA sequences from the remainder of fine-needle aspirate after cytological examination and evaluated its diagnostic efficacy in clinical situations. METHODS: Conventional diagnostic procedures including FNAC and M tuberculosis PCR were performed simultaneously in 29 cases that had been suspected to be cervical tuberculous lymphadenitis on patients' first visit. The results of FNAC and M tuberculosis PCR were compared with the clinical outcomes after several months of follow-up and pathological results from open biopsy of some cases. RESULTS: Among the 17 cases of cervical tuberculous lymphadenitis diagnosed in clinical situations, M tuberculosis DNA was found by PCR in 13 cases (76.4%). Negative findings on PCR were achieved in 12 cases, which revealed non-granulomatous lymphadenopathy. CONCLUSION: From these results, we conclude that M tuberculosis PCR using the remainder of aspirate for cytological examination is a very useful tool for the diagnosis of cervical tuberculous lymphadenitis, and its clinical application with FNAC could reduce the necessity for open biopsy.

Adolescent↗

Molecular cloning, overproduction and characterization of the Bacillus cereus IMP dehydrogenase.

The gene of IMP dehydrogenase of Bacillus cereus ts-4, a temperature-sensitive mutant of B. cereus JCM 2152, was subcloned and its sequence was analyzed. A B. cereus ts-4 DNA fragment of 2,065 bp containing the entire impdh gene and flanking regions was sequenced. The fragment contained an open reading frame of 1,527 bp encoding 509 amino acids with a calculated molecular mass of 55,390 Da. The impdh sequence of JCM 2152 was also analyzed by TA cloning using PCR products amplified with primers from B. cereus ts-4 impdh gene. The gene amplified by PCR was expressed in Escherichia coli using a pET17 x b expression plasmid. The N-terminal amino acid sequence of the overproduced enzyme was identified as Met-Trp-Glu-Ser-Lys-Phe-Val-Lys-Glu-Gly-Leu-Thr-Phe-AspAsp-Val-Leu -Leu-Val- Pro. The overproduced enzyme was eluted at a molecular mass of about 225 kDa by gel filtration. The molecular mass of the subunit was estimated to be 56 kDa by SDS-PAGE. The overproduced enzyme was active against IMP, IDP, and ITP, and showed the highest activity at pH 9.5. These properties of the recombinant enzyme were almost identical to those of IMP dehydrogenase of B. cereus.

Amino Acid Sequence↗

Clinical breast examination for screening of asymptomatic women: the importance of clinical breast examination for breast cancer detection.

Of 489 asymptomatic women who were referred to our institute from other screening clinics, 46 were eventually proven to be breast cancer patients, and this number equated to 8.1% of the 565 breast cancer patients treated in our institute during the period of January 1997 to December 1998. Among the 46 cancer patients of the initial 489 asymptomatic women, twenty-five (54.35%) were detected by mammogram alone, six (13.04%) by clinical breast examination (CBE) alone, and the remaining 15 (32.61%) by both mammogram and CBE. In context with age, the mammographic sensitivity for cancer detection was 100% for women aged over 60, 91% for 50s, 78.9% for 40s, and 75% for 30s, and inversely correlated with the patient's age. Among the 25 cancers detected by mammogram alone, 18 (72%) belonged to DCIS or stage I. In contrast, four (66.7%) of six cancers detected by CBE alone and nine (60%) of 15 cancers by both CBE and mammography were included in stage IIa or IIb. However, the total incidence of early cancers (stages 0 and I) was significantly higher in the screening group than in the symptomatic group (p < 0.01). These results suggest that the role of mammography is important in the detection of cancers in their earlier stage and CBE is helpful in reducing false negative results in breast cancer screening. In conclusion, film mammography is the best tool for the detection of microcalcification and is useful for the detection of earlier lesions, but is not perfect for the detection of breast cancer particularly in young women. A careful CBE is an essential part of breast screening in order to reduce false-negative results.

Adult↗

Divergent effect of cyclosporine on Th1/Th2 type cytokines in patients with severe, refractory rheumatoid arthritis.

OBJECTIVE: To investigate the effect of cyclosporine on cytokine production, especially on T helper 1 (Th1) and T helper 2 (Th2) type cytokines, in patients with rheumatoid arthritis (RA). METHODS: A 16 week randomized, double blind, placebo controlled study of cyclosporine (2.5 to 4 mg/kg/day) was conducted in 40 patients with severe, refractory RA who had residual inflammation and disability despite partial responses to prior maximal tolerated dose of methotrexate (MTX; < 15 mg/week) and low dose prednisone (< 10 mg/day). Clinical and laboratory variables, and circulating levels of interleukin 2 (IL-2), IL-4, IL-10, IL-12, tumor necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma) measured by ELISA were compared between patients (cyclosporine group) treated with cyclosporine plus MTX and those (placebo group) treated with placebo plus MTX at entry and at 16 weeks. RESULTS: At 16 weeks, the cyclosporine group (n = 17), compared with the placebo group (n = 17), had greater decreases in tender joints, swollen joints, patient global assessment, patient self-assessed disability, and C-reactive protein, as well as having more patients with > 20% improvement. Comparison of circulating cytokines at entry and at 16 weeks showed significant decreases of IL-2 (median -61 vs 7 pg/ml; p = 0.004) ("+" denotes increase, "-" denotes decrease), IL-12 (median -313 vs -14 pg/ml; p = 0.002), TNF-alpha (median -55 vs 5 pg/ml; p < 0.001), and IFN-gamma (median -21 vs 5 pg/ml; p = 0.003), and a significant increase of IL-10 (median 55 vs -12 pg/ml; p < 0.001) in the cyclosporine group compared with the placebo group. The degree of IL-10 increases correlated strongly with the degree of IL-12 decreases in the cyclosporine group (r = 0.572, p = 0.016). However, there was no change in circulating IL-4 between the 2 groups. Within the cyclosporine group, the improved patients (n = 10) compared to the non-improved patients (n = 7) had a greater increase in circulating IL-10 (median 172.0 vs 85.2%; p = 0.01). The rate of increase of IL-10 strongly correlated with the rate of improvement of joint scores (r = 0.718, p = 0.001) after administration of cyclosporine. CONCLUSION: Our results suggest that the therapeutic effect of cyclosporine is achieved by correcting a Th1/Th2 imbalance (a shift of Th1 type to Th2 type), which may be involved in the pathogenesis of RA; and that circulating IL-10 is useful to assess the clinical improvements in patients with RA after administration of cyclosporine.

Adult↗

IgG antibodies to type II collagen reflect inflammatory activity in patients with rheumatoid arthritis.

OBJECTIVE: To determine the clinical significance of IgG antibodies to type II collagen (CII) and to define any correlation of antibodies to CII with the inflammatory response in patients with rheumatoid arthritis (RA). METHODS: IgG antibodies to native human type II collagen (IgG anti-CII) were measured in sera and synovial fluid (SF) from patients with RA, patients with osteoarthritis (OA), and healthy controls by an improved ELISA. Demographic, clinical, and laboratory data including tumor necrosis factor-alpha (TNF-alpha) and interleukin 6 (IL-6) levels were also obtained at the time of sampling in patients with RA. RESULTS: The median level and positivity for circulating IgG anti-CII were higher in patients with RA (n = 297) than patients with OA (n = 34) and healthy controls (n = 50) (p < 0.001). The titers of IgG anti-CII in SF were also higher in RA (n = 45) than in OA (n = 16) (p < 0.001). In paired samples, the levels of IgG anti-CII were significantly higher in SF compared to the sera in patients with RA (n = 45) (p < 0.001), but levels were not different in patients with OA (n = 16). Circulating IgG anti-CII converted from positive to negative in 13 patients (10.7%) and from negative to positive in 18 patients (14.8%) among 122 patients with RA in whom IgG anti-CII were monitored sequentially at a mean interval of 12.2 months. IgG anti-CII positive patients (n = 98) had shorter disease duration (p = 0.04) and less frequent deformity (p = 0.013), and higher median erythrocyte sedimentation rate (ESR) (p = 0.001) and C-reactive protein (CRP) (p < 0.001) than IgG anti-CII negative patients (n = 120). The levels of IgG anti-CII correlated with CRP (r = 0.270) and ESR (r = 0.253). CRP decreased significantly in patients (n = 13) who converted from IgG anti-CII positive to negative (p = 0.013). IgG anti-CII positive patients (n = 40) had higher levels of TNF-alpha and IL-6 than negative patients (n = 40) (p < 0.001). Levels of IgG anti-CII correlated well with TNF-alpha (r = 0.617) and IL-6 (r = 0.347). CONCLUSION: Increased IgG anti-CII in sera and SF in RA correlated directly with acute phase reactants and the proinflammatory cytokines TNF-alpha and IL-6. Our data suggest that IgG anti-CII could reflect inflammatory activity with a potential to destroy cartilage in the early stages of RA.

Acute-Phase Proteins↗

Glucocorticoid receptor-induced down-regulation of MMP-9 by ginseng components, PD and PT contributes to inhibition of the invasive capacity of HT1080 human fibrosarcoma cells.

We examined the effects of the purified ginseng components, panaxadiol (PD) and panaxatriol (PT), on the expression of matrix metalloproteinase-9 (MMP-9) in highly metastatic HT1080 human fibrosarcoma cell line. A significant down-regulation of MMP-9 by PD and PT was detected by Northern blot analysis. However, the expression of MMP-2 was not changed by treatment with PD and PT. Quantitative gelatin based zymography confirmed a markedly reduced expression of MMP-9, but not MMP-2 in the treatment of PD and PT. To investigate whether the reduced level of MMP-9 by PD and PT affects the invasive capacity of HT1080 cells, we conducted an in vitro invasion assay with PD and PT treated cells. The results of the in vitro invasion assay revealed that PD and PT reduced tumor cell invasion through a reconstituted basement membrane in the transwell chamber. Because of the similarity of chemical structure between PD, PT and dexamethasone (Dexa), a synthetic glucocorticoid, we investigated whether the down-regulation of MMP-9 by PD and PT were mediated by the nuclear translocation of glucocorticoid receptor (GR). Increased GR in the nucleus of HT1080 human fibrosarcoma cells treated by PD and PT was detected by immunocytochemistry. Western blot and gel retardation assays confirmed the increase of GR in the nucleus after treatment with PD and PT. These results suggest that GR-induced down-regulation of MMP-9 by PD and PT contributes to reduce the invasive capacity of HT1080 cells.

Cell Nucleus↗

Clear benefit of mycophenolate mofetil-based triple therapy in reducing the incidence of acute rejection after living donor renal transplantations.

BACKGROUND: According to a pooled analysis of three randomized clinical studies concerning the prevention of acute rejection in cadaveric renal transplantation, mycophenolate mofetil (MMF) proved superior to azathioprine or placebo in conjunction with cyclosporine (CsA) and steroids. MMF-treated patients showed reduced incidence and severity of acute rejection, similar graft survival, and better graft function over 12 months. However, the multicenter trials did not include the Asian recipients of living donor kidneys. METHODS: To assess the efficacy of MMF as the third component of a triple therapy in addition to CsA-Neoral and steroids in living donor renal transplantation recipients in Asians, a total of 100 recipients were randomized to receive CsA-Neoral and steroids (control group, n=50), or MMF-based triple therapy (1.0 g of MMF twice daily from postoperative day 2, MMF group, n=50). The dosing plan for Neoral and steroids was essentially same between groups. During 12 months of follow-up, we compared the incidence of acute rejection, adverse events such as infections, and 12-month actual graft and patient survival. RESULTS: The graft and patient survival at 1 year was excellent in both groups: 96/98% in the control group and 98/100% in the MMF group, respectively. MMF significantly reduced the proportion of patients with at least one episode of acute rejection (34% in the control group vs. 14% in the MMF group), cumulative incidence of acute rejection episodes (46% vs. 16%), and requirement of antilymphocyte antibody (21.7% vs. 12.5%). In the MMF group, viral infection such as herpes zoster or chicken pox was more prevalent than in the control group. CONCLUSIONS: Like cadaveric renal transplantation, this open clinical trial showed MMF to be effective in reducing the incidence and severity of acute rejection if used in conjunction with Neoral and steroids after living donor renal transplantation in Asian ethnicity.

Acute Disease↗