Dissipation of foliar residues of diafenthiuron and its metabolites.
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Biodegradation, Environmental↗
Biomedical subjects
Y H Kim
Publications and source records attributed to Y H Kim.
Effect of melatonin on antioxidant status in the plasma of cyclosporine-treated rats.
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Animals↗
Increased risk of peristomal wound infection after percutaneous endoscopic gastrostomy in patients with diabetes mellitus.
BACKGROUND: Results of prospective studies on the effect of prophylactic antibiotics before percutaneous endoscopic gastrostomy are conflicting. Factors for increased risk of peristomal wound infection have not been clearly identified. AIM: To evaluate the incidence of complications of percutaneous endoscopic gastrostomy and to determine the predictors of wound infection. PATIENTS AND METHODS: Percutaneous endoscopic gastrostomy was performed on 134 patients in different disease groups between January 1996 and June 2000. Medical records were carefully reviewed for demographic data, indications for percutaneous endoscopic gastrostomy, use of prophylactic antibiotics, complications and comorbid conditions predisposing to wound infection. RESULTS: Of 134 patients, 22 (16.4%) developed complications after percutaneous endoscopic gastrostomy Wound infection, the most common complication, occurred in 19 patients (14.2%) and Pseudomonas aeruginosa was the most frequently isolated microorganism. In univariate analysis, non-malignant disease and diabetes mellitus were significantly associated with peristomal wound infection after percutaneous endoscopic gastrostomy. In multivariate analysis, only diabetes mellitus was an independent risk factor for the development of peristomal wound infection after percutaneous endoscopic gastrostomy (p = 0.035) CONCLUSIONS: Patients with diabetes mellitus have a higher risk of peristomal wound infection after percutaneous endoscopic gastrostomy.
Diabetes Complications↗
Association between CYP2D6 genotype and tardive dyskinesia in Korean schizophrenics.
The CYP2D6 gene codes for human cytochrome P450 2D6 enzyme, which is responsible for the metabolism of many psychiatric drugs. In schizophrenic patients treated with neuroleptics, decreased or loss of function CYP2D6 alleles may contribute to the development of tardive dyskinesia (TD), a movement disorder that frequently occurs with chronic neuroleptic treatment. The goal of this study was to determine whether the occurrence of TD is associated with CYP2D6 genotype in a cohort of Korean schizophrenics by employing a CYP450 GeneChip((R)) oligonucleotide microarray and PCR assays to screen for 19 CYP2D6 alleles. Our results revealed that males with at least one decreased or loss of function allele have a moderately greater chance of developing TD than males with only wild-type alleles. Female schizophrenics did not have a significantly greater chance of developing TD. Our results demonstrate the utility of CYP2D6 microarrays to assess genotype status in this Korean cohort.
Adolescent↗
Long-term stress and Helicobacter pylori infection independently induce gastric mucosal lesions in C57BL/6 mice.
BACKGROUND: Long-term psychological stresses may have a role in the pathogenesis of peptic ulcer. However, the interaction between stress and Helicobacter pylori infection in the development of peptic ulcer is not established. The aim of this study was to elucidate the roles of long-term stress and H. pylori infection in the development of gastric mucosal lesions in mice. METHODS: The Sydney strain (SS1) of H. pylori was inoculated into the stomach of C57BL/J6 mice. Twelve weeks later, mice with or without H. pylori infection were exposed to long-term repeated water-immersion-restraint stress (WIRS) for 12 h per day, 3 times per week, for 8 weeks. Gastric mucosal lesions were evaluated both macroscopically (ulcer index) and microscopically (Updated Sydney System). RESULTS: The long-term WIRS induced mild inflammation, oedema, interstitial haemorrhage and superficial erosions in the stomach of mice both with and without H. pylori infection. The degree of mucosal inflammation or atrophy in H. pylori-infected mice was not influenced by the stress. In the mice without H. pylori infection, the ulcer index of the stressed mice was greater than that of non-stressed mice (1.66 +/- 0.39 versus 0.17 +/- 0.08, P = 0.007). In the mice with H. pylori infection, the ulcer index (mean +/- s(x)) of the stressed mice was also greater than that of non-stressed mice (2.31 +/- 0.59 versus 0.64 +/- 0.22, P = 0.027). CONCLUSIONS: The present study showed that long-term stress can induce gastric mucosal inflammation and erosions, and this effect may occur independently of H. pylori infection.
Animals↗
Reductive dechlorination of PCE and TCE by vitamin B12 and ZVMs.
The reductive dechlorination of tetrachloroethene (PCE) and trichloroethene (TCE) catalyzed by vitamin B12 was examined when zero valent metals (ZVMs) were used as bulk electron donors in batch reactors. UV-visible spectra showed that zinc reduces vitamin B12 Co(III) to vitamin B12 Co(I) through B12 Co(II) and iron reduces vitamin B12 Co(III) to vitamin B12 Co(II). Thus iron, the most popular ZVM reductant, does not have enough reduction potential toreduce vitamin B12 to the super-reduced vitamin B12(I), which has been shown to be an active species in reductive dechlorination. Dechlorination of PCE and TCE by iron and zinc in the presence of vitamin B12 showed that the zinc and vitamin B12 combination greatly enhances the reaction rates for both PCE and TCE, but iron and vitamin B12 result in an increase in reactivity only for PCE degradation, not for TCE degradation in comparison with metals only. This result indicates vitamin B12(I) is active towards both PCE and TCE degradation while vitamin B12(II) is active only towards PCE. Calculated activation energies for the dechlorination of PCE in the presence of Vitamin B12 showed that vitamin B12 lowered the activation energy about 40-60 kJ mol(-1) for both metals.
Carcinogens↗
Off-odor volatiles and pink color development in precooked, irradiated turkey breast during frozen storage.
The effect of irradiation on color, lipid oxidation, and volatile production of precooked, irradiated turkey breast during frozen storage was studied. Turkey breast muscles were precooked, aerobically or vacuum-packaged, irradiated at 0, 2.5, or 5.0 kGy using a linear accelerator (electron beam), and then frozen-stored at -40 C. Lipid oxidation, volatiles, color values, gas production, and oxidation-reduction potential (ORP) of meat were determined during 3-mo storage periods. Ionizing radiation produced characteristic off-odor volatiles (dimethyldisulfide and methylthioethane) and lipid oxidation products in precooked, frozen turkey breast. The production of volatiles was accelerated by the confounding effect of high irradiation dose, aerobic packaging, and increased storage time. Volatile production and color changes in irradiated, precooked turkey breast were induced by different mechanisms. Irradiation increased pink color in precooked, vacuum-packaged turkey breast, and the pink color was stable during frozen storage. Decreased ORP and increased CO in irradiated meat indicated that denatured CO-heme pigments could be responsible for the pink color in precooked, irradiated turkey breast. Vacuum packaging was better than aerobic packaging in preventing lipid oxidation and oxidation-dependent volatile production, but pink color in precooked, irradiated turkey breast during frozen storage was maintained.
Animals↗
Total knee arthroplasty in neuropathic arthropathy.
We describe the results of total knee arthroplasty (TKA) undertaken for severe, neurosyphilitic Charcot arthropathy in ten patients (19 knees). A cemented condylar, constrained prosthesis was implanted in all but two knees. The mean follow-up was 5.2 years (5 to 6). The mean knee score before operation was 36.5 points (30 to 42) which improved to 76 points (58 to 90) after operation as judged by the Hospital for Special Surgery score. At final follow-up three knees (16%) had aseptic loosening which required salvage by an arthrodesis, six (31%) were functioning poorly and ten (53%) were satisfactory. We conclude that although Charcot arthropathy is not an absolute contraindication to total knee replacement, there is a high incidence of serious complications.
Arthropathy, Neurogenic↗
Ozonation of Han River humic substances.
This study investigated the characteristics of extracted humic substances (HS) which are ubiquitous in river waters and affect the treatment of the water. HS were extracted from the Han River and the samples obtained were analyzed before/after oxidation with the following analytical methods: DOC, THMFP, UV-abs, chemical composition, molecular weight distribution, IR. Ozonation experiments were conducted in batch-type reactors. Ozone dose was 1 mg/L and contact time was varied from 0 to 20 minutes. The fraction of hydrophobic matter was 56.0% of total organic carbon in the Han River and the ratio of humic/fulvic acids was 22.4/77.6, showing high fractions of aromatic and/or double carbon bond functional groups and high fractions of saturated aliphatic carbons. Oxygen fraction of Han HS was relatively high compared with other humic substances (Suwannee River humic and fulvic acids), which are consistent with the results of IR spectra. The IR spectra showed the increase in aliphatic groups by ozonation of the Han HS. Humic substances could not completely be oxidized to CO2, H2O etc., but were partly oxidized to low molecular weight matter (aliphatics, aldehydes, carboxylics, polysaccharides etc.), so low removal efficiencies in terms of DOC (31-35% with 5 minute contact) were observed. For UV254, 5 minute or shorter contact showed more than 80% removal efficiencies.
Benzopyrans↗
Nucleotide sequence and cell cycle-associated differential expression of ZF5128, a novel Kruppel type zinc finger protein gene.
The nucleotide sequence of the ZF5128 gene, encoding a novel Kruppel type zinc finger protein, has been determined. The ZF5128 gene has a predicted 553-amino acid open reading frame, encoding a putative 61 kDa zinc finger protein. The N-terminus of the ZF5128 coding region has a well-conserved Kruppel-associated box (KRAB) domain that consists of KRAB box A and B, whereas the C-terminus contains a Kruppel type C2H2 zinc finger domain possessing nine C2H2 zinc finger motifs in tandem arrays with the highly conserved space region of the H/C-link. Each C2H2 zinc finger motif has a typical consensus sequence of CX2CX3FX5LX2HX3H. A 3.2 kb transcript specific for ZF5128 was expressed at high levels in the spleen, thymus, and peripheral blood leukocyte, and weakly expressed in the prostate, ovary, small intestine, colon (mucosal lining), placenta, lung, and pancreas. Although there was no detectable ZF5128 mRNA in unstimulated human peripheral T cells, it was first detectable 1.5 h after activation by anti-CD3 plus anti-CD28, and reached a maximum in 25-30 h. During the cell cycle progression of Jurkat T cells, the expression of ZF5128 mRNA appeared to be induced in G1 and reached a maximum in the S phase, but declined as the cells entered the G2/M phase. The 12-O-tetradecanoylphorbol 13-acetate-induced monocytic differentiation of U937, which also resulted in growth arrest, down-regulated the expression of ZF5128 mRNA. Taken together, these results indicate that ZF5128 is a novel gene encoding a Kruppel type C2H2 zinc finger protein and is regulated at the transcriptional level depending on tissue type and the cell cycle status to support cell proliferation.
Amino Acid Sequence↗
Diabetic alterations in cardiac sarcoplasmic reticulum Ca2+-ATPase and phospholamban protein expression.
Diabetic cardiomyopathy has been suggested to be caused by abnormal intracellular Ca2+ homeostasis in the myocardium, which is partly due to a defect in calcium transport by the cardiac sarcoplasmic reticulum (SR). In the present study, the underlying mechanism for this functional derangement was investigated with respect to SR Ca2+-ATPase and phospholamban (the inhibitor of SR Ca2+-ATPase). The maximal Ca2+ uptake and the affinity of Ca2+-ATPase for Ca2+ were decreased, and exogenous phosphorylation level of phospholamban was higher in streptozotocin-induced diabetic rat SR. Levels of both mRNA and protein of phospholamban were significantly increased in the diabetic hearts, whereas those of SR Ca2+-ATPase were significantly decreased. Consequently, the relative phospholamban/Ca2+-ATPase ratio was 1.88 in the diabetic hearts, and these changes were correlated with changes in the rates of SR Ca2+ uptake. However, phosphatase pretreatment of phospholamban for dephosphorylation of the sites phosphorylated in vivo did not change the levels of subsequent phospholamban phosphorylation in either control or diabetic rat hearts. The above data indicated that the increased phospholamban phosphorylation was not due to autonomic dysfunction but possibly due to increased phospholamban expression. These findings suggest that reduction of the SR Ca2+-ATPase level would contribute to decreased rates of SR Ca2+ uptake and that this function is further impaired by the enhanced inhibition by phospholamban due to its increased expression in the diabetic heart.
Animals↗
Hydrolysis of linear DNA duplex catalyzed by Co(III) complex of cyclen attached to polystyrene.
To design artificial restriction enzymes, synthetic catalytic centers that effectively hydrolyze linear double-stranded polydeoxyribonucleotides are needed. The Co(III) complex of cyclen (CoCyc) attached to polystyrene derivatives hydrolyzes linearized pUC18 DNA with half-lives as short as 30 min at 25 degrees C. The catalytic activity of CoCyc is enhanced by >150 times on attachment to the resin.
Catalysis↗
Thermal stability of human ferritin: concentration dependence and enhanced stability of an N-terminal fusion mutant.
Though human L-chain ferritin has been known to be more resistant to physical denaturation than H-type ferritin, its stability characteristics and kinetic information have not been reported in detail. Overexpressed recombinant ferritin (FTN) in Escherichia coli formed inclusion bodies through noncovalent molecular interaction and easily dissolved with regaining the iron-uptake activity by a simple pH-shift process at high protein concentration (>600 mg l(-1)). FTN was relatively thermostable at low protein concentration (0.2 g l(-1)), but it became extremely thermolabile at high protein concentration (1.3 g l(-1)), i.e., more than 80% of FTN was coprecipitated within 5 min under the same heat-induced denaturation condition. Aggregation rate constant for initial 5 min at high protein concentration was 6.04 x 10(-3) s(-1) for FTN. Surprisingly, glucagon. ferritin mutant (GFTN), consisting of an N-terminus fusion partner, human glucagon (29-residue alpha-helical peptide), showed significantly enhanced thermal stability even at high protein concentration. That is, in spite of 40-min heat treatment, more than 50% of GFTN the still remained soluble with maintaining the same functional properties. The aggregation rate constants were 2.75 x 10(-4) and 2.80 x 10(-4) s(-1) at low and high concentration, respectively, for GFTN. These results suggest a critical participation of the N-terminal domain of ferritin in the temperature-induced aggregation pathway. Presumably, partially denatured amino terminus of FTN is involved in nonspecific molecular interaction resulting in the off-pathway aggregation. It is notable that the purified GFTN showed the same molar capacity of iron (Fe(+3)) storage as standard ferritin. From the analysis of fluorescence emission spectrum, the physical stability of GFTN was also very comparable to that of standard ferritin under the various denaturation conditions induced by GdnHCl.
Drug Stability↗
Progressive action potential duration shortening and the conversion from atrial flutter to atrial fibrillation in the isolated canine right atrium.
OBJECTIVES: We sought to evaluate the effects of progressive shortening of the action potential duration (APD) on atrial wave front stability. BACKGROUND: The mechanisms of conversion from atrial flutter to atrial fibrillation (AF) are unclear. METHODS: Isolated canine right atria were perfused with 1 to 5 micromol/l of acetylcholine (ACh). We mapped the endocardium by using 477 bipolar electrodes and simultaneously recorded transmembrane potentials from the epicardium. The APD(90) was measured during regular pacing (S(1)) with cycle lengths of 300 ms. Atrial arrhythmia was induced by a premature stimulus (S(2)). RESULTS: At baseline, only short runs of repetitive beats (<10 cycles) were induced. After shortening the APD(90) from 124 +/- 15 ms to 72 +/- 9 ms (p < 0.01) with 1 to 2.5 micromol/l of ACh, S(2) pacing induced single, stable and stationary re-entrant wave fronts (307 +/- 277 cycles). They either anchored to pectinate muscles (5 tissues) or used pectinate muscles as part of the re-entry (4 tissues). When ACh was raised to 2.5 to 5 micromol/l, the APD(90) was further shortened to 40 +/- 12 ms (p < 0.01); S(2) pacing induced in vitro AF by two different mechanisms. In most episodes (n = 13), AF was characterized by rapid, nonstationary re-entry and multiple wave breaks. In three episodes with APD(90) <30 ms, AF was characterized by rapid, multiple, asynchronous, but stationary wave fronts. CONCLUSIONS: Progressive APD shortening modulates atrial wave front stability and converts atrial flutter to AF by two mechanisms: 1) detachment of stationary re-entry from the pectinate muscle and the generation of multiple wave breaks; and 2) formation of multiple, isolated, stationary wave fronts with different activation cycle lengths.
Acetylcholine↗
The induction of BDNF and c-fos mRNA in the hippocampal formation after febrile seizures.
In this study we investigated the expression of brain-derived neurotrophic factor (BDNF) and c-fos mRNA in the hippocampal formation after febrile seizures (FSs) with in situ hybridization histochemistry using riboprobes. The induction of BDNF mRNA was firstly observed in the dentate gyrus at 30 min after FSs. The expression in the dentate gyrus peaked at 3 h and returned to basal level at 24 h. It was also observed in the CA3 of hippocampus from 2 to 3 h. The induction of c-fos mRNA was observed in the dentate gyrus at 30 min and 1 h. These observations suggest that BDNF and c-fos are the genes whose expression can be altered by FSs and might be related to pathologic alterations after FSs.
Animals↗
Ectopic expression of the coxsackievirus and adenovirus receptor increases susceptibility to adenoviral infection in the human cervical cancer cell line, SiHa.
The expression level of the coxsackievirus and adenovirus receptor (CAR) gene in human cervical cancer cell lines (Hela, Caski, HT-3, and SiHa) appears to be correlated with their susceptibility to adenoviral vector-based gene transfer. Hela, Caski, and HT-3 cells, which express the CAR molecule on the cell surface, showed a higher susceptibility to infection of AdCMVGFP than SiHa cells with no detectable level of CAR expression. Transient expression of the CAR gene in SiHa cells dramatically enhanced the susceptibility to adenoviral infection. Furthermore, SiHa-CAR, a stable transfectant which expresses the CAR gene showed a highly increased susceptibility to adenoviral infection in contrast to SiHa. These results demonstrate that the low susceptibility of SiHa to adenoviral infection is closely related to its loss of the CAR gene expression. In addition, the low infection efficacy can be overcome by the ectopic expression of the CAR gene. These results also give insight into a possible application of the CAR gene to adenovirus-mediated gene delivery.
Adenoviridae↗
Protection by pyruvate against transient forebrain ischemia in rats.
Pyruvate has a remarkable protective effect against zinc neurotoxicity. Because zinc neurotoxicity is likely one of the key mechanisms of ischemic brain injury, the neuroprotective effect of pyruvate was tested in a rat model of transient forebrain ischemia. Control experiments in mouse cortical culture showed that pyruvate almost completely blocked zinc toxicity but did not attenuate calcium-overload neuronal death. Adult rats subjected to 12 min forebrain ischemia exhibited widespread zinc accumulation and neuronal death throughout hippocampus and cortex 72 hr after reperfusion. However, rats injected intraperitoneally with sodium pyruvate (500-1000 mg/kg) within 1 hr after 12 min forebrain ischemia showed almost no neuronal death. In addition, the mortality was markedly decreased in the pyruvate-protected groups (3.8%) compared with the NaCl-injected control group (58.1%). The neuroprotective effect persisted even at 30 d after the insult. The spectacular protection without noticeable side effects makes pyruvate a promising neuroprotectant in human ischemic stroke.
Animals↗
Development of a packaging cell line for propagation of replication-deficient adenovirus vector.
A human embryonic kidney cell line 293 is widely used for adenovirus production and propagation. With this cell line, however, replication-competent virus (RCV) is frequently generated, especially during large-scale production and successive propagation because 293 cells contain not only E1 gene but also non-E1 adenovirus gene. Homologous recombination between non-E1 region of 293 genomic DNA and its homologous region in the recombinant adenoviral vector generate RCV. To overcome this problem, we developed a new packaging cell line, Hela-E1, which contains minimum E1 region and from which non-E1 adenoviral region that is homologous with recombinant adenovirus vector was excluded. No RCV was detected during adenovirus propagation in Hela-E1 compared to in 293. In addition, adenovirus-p53 produced in HeLa-E1 was able to overexpress p53 protein when introduced into an ovarian cancer cell line, SKOV3. These results may have a significant impact on the development of packaging cell lines for replication-deficient adenovirus production.
Adenoviridae↗