Biomedical subjects

W K Kim

Publications and source records attributed to W K Kim.

At least 91 records · Page 5Linked to original sources

PubMed1999

Attenuation of NMDA receptor activity and neurotoxicity by nitroxyl anion, NO-.

Recent evidence indicates that the NO-related species, nitroxyl anion (NO), is produced in physiological systems by several redox metal-containing proteins, including hemoglobin, nitric oxide synthase (NOS), superoxide dismutase, and S-nitrosothiols (SNOs), which have recently been identified in brain. However, the chemical biology of NO- remains largely unknown. Here, we show that NO- -unlike NO*, but reminiscent of NO+ transfer (or S-nitrosylation)- -reacts mainly with Cys-399 in the NR2A subunit of the N-methyl-D-aspartate (NMDA) receptor to curtail excessive Ca2+ influx and thus provide neuroprotection from excitotoxic insults. This effect of NO- closely resembles that of NOS, which also downregulates NMDA receptor activity under similar conditions in culture.

Animals↗

PubMed1999

Prognostic value of DNA flow cytometry in stomach cancer: a 5-year prospective study.

The role of DNA flow cytometry in the prediction of prognosis for patients with stomach cancer remains to be defined. Thus we studied prospectively the role of DNA flow cytometry as a prognosis indicator in stomach cancer patients in a high-incidence area. Between November 1990 and December 1992, primary stomach cancer tissues were obtained from the surgical specimens from 217 patients (148 male, 69 female). DNA flow cytometric analyses of DNA ploidy and S-phase fraction were performed and the results were correlated with patient survival. The median age of the patients was 55 years (range 24-78). Aneuploid cell population was found in 114 of 217 samples (53%). Tumour S-phase fraction was obtained in 96 of 103 diploid tumours (93%) and 61 of 114 aneuploid tumours (54%). After median follow-up of 66.1 months, the patients with tumours with an S-phase fraction over 17% had significantly worse survival rates than patients with tumours with S-phase fractions of lower than 8% or 8-17% (45% vs 59% and 63% of patients surviving, P = 0.007). Tumour ploidy status did not correlate with patient survival. Multivariate analyses showed that the TNM stage remained the most important prognostic indicator. The tumour S-phase fraction was also an independent prognostic indicator (relative risk 2.300, 95% CI, 1.252-4.223). Tumour S-phase fraction obtained by DNA flow cytometry is an independent prognostic indicator for the survival of the patients with stomach cancer.

Adult↗

PubMed1999

Randomized comparison of two different schedules of granulocyte colony-stimulating factor administration after allogeneic bone marrow transplantation.

We performed a randomized trial to determine whether there are differential effects of G-CSF when it is either started on the day (day 0 group) or on the 6th day of marrow infusion (day 5 group) in the allogeneic BMT setting. G-CSF 450 microg was given intravenously daily until the peripheral blood ANC was over 3000/microl. Between May 1995 and April 1998, 60 patients were enrolled (30 in each group). Median number of days of G-CSF administration was significantly longer for the day 0 group (18.5 vs 14.0 days, P < 0. 001). Median days to an ANC over 500/microl were the same in both groups (16 days). Median days to an unsupported platelet count of 20 000/microl did not show significant differences (29.5 vs 28 days, P = 0.202). The frequency of hepatic VOD was higher for the day 0 group (66.7 vs 40.0%, P = 0.038). Mean plasma antithrombin III level was significantly lower in the day 0 group on post-transplant day 7 (83.6 vs 93.9%, P = 0.009). Patients in the day 0 group showed significantly worse 100-day survival (25/30 vs 30/30 surviving respectively, P = 0.019). In conclusion, early initiation of G-CSF after allogeneic BMT did not facilitate marrow engraftment. In addition, early administration of G-CSF was associated with a higher frequency of VOD and a significant fall in plasma antithrombin III level.

Adolescent↗

PubMed1999

Effect of topically applied 0.1% dexamethasone on endothelial healing and aqueous composition during the repair process of rabbit corneal alkali wounds.

PURPOSE: The effects of topical dexamethasone on the endothelial healing and the change of aqueous compositions were investigated during the repair process of alkali-wounded rabbit cornea. METHODS: A central corneal alkali wound was produced by a 60 sec application of a 5.5 mm round filter paper soaked in 1N NaOH onto one eye of each rabbit. The eyes subsequently were treated topically with either 0.1% dexamethasone or a balanced salt solution (BSS) 4 times per day for 8 weeks. Endothelial wound morphometry was performed after alizarin red and trypan blue staining. The concentrations of ascorbic acid, glucose, and the ions, Na+, K+, Ca2+ and Mg2+, were measured in the aqueous humor. RESULTS: Endothelial healing in control (alkali-wounded but not treated with dexamethasone) corneas showed a biphasic pattern of healing: an initial short-term healing for the first week and then a late long-term healing following the secondary endothelial breakdown. Topical administration of 0.1% dexamethasone deterred endothelial healing during the early period and prevented the secondary endothelial breakdown. However, the total repair process of endothelium was accelerated by the dexamethasone-treatment. Among the various components of the aqueous humor examined, ascorbic acid seemed the most sensitive to change caused by the alkali injury and dexamethasone treatment. CONCLUSIONS: The present data indicate that dexamethasone may have a therapeutic potential in the management of endothelial healing after corneal alkali injury.

Administration, Topical↗

PubMed1999

Immunostimulated glial cells potentiate glucose deprivation-induced death of cultured rat cerebellar granule cells.

The present study investigates whether immunostimulated glial expression of inducible nitric oxide synthase influences the glucose deprivation-induced death of rat cerebellar granule cells (CGC). CGC/glia cocultures were immunostimulated by interferon-gamma (200 U/ml) and lipopolysaccharides (1 microg/ml) and 2 days later were challenged by glucose deprivation. Neurotoxicity was assessed by measuring the release of lactate dehydrogenase. Neither a 2-h glucose deprivation nor a 2-day immunostimulation altered the viability of CGC. A 2-day immunostimulation, however, markedly potentiated the glucose deprivation-induced death of CGC. The increased death of glucose-deprived CGC after immunostimulation was mimicked by the nitric oxide (NO) releasing reagent 3-morpholinosydnonimine (SIN-1) and was partially prevented by the NO synthase (NOS) inhibitor N(G)-nitroarginine. The increased death of glucose-deprived CGC either after immunostimulation or by SIN-1 was not altered by various N-methyl-D-aspartate (NMDA) and non-NMDA receptor antagonists. Because superoxide dismutase and catalase, which remove superoxide anion, decreased the augmented death of glucose-deprived immunostimulated CGC, the reaction of NO with superoxide to form peroxynitrite appears to be implicated in the potentiated neurotoxicity. Our data indicate that immunostimulated glial cells potentiate the death of glucose-deprived neurons in part through the expression of inducible NOS but not through NMDA receptor activation. Potentiation of glucose-deprived CGC death by immunostimulated glial cells may be clinically implicated in the tendency of recurrent ischemic insults to be more severe and fatal than an initial ischemic insult.

Animals↗

PubMed1999

Phase II trial of a novel platinum analog, SKI 2053R, in patients with previously untreated extensive-stage small-cell lung cancer.

A phase II trial of a novel platinum analog, SKI 2053R, was performed in patients with previously untreated extensive-stage disease (ED) small-cell lung cancer (SCLC). SKI 2053R was administered at the dose of 400 mg/m2 every 3 to 4 weeks as a 1-h infusion. After the first cycle, the dose was escalated to 440 mg/m2 based on toxicity. Thirty-eight patients (31 male) were enrolled between June 1995 and August 1997. The median age was 61 years (range, 36-70 years). Six of 37 evaluable patients achieved a partial response (16.2%; 95% confidence interval [CI], 4.4-28.0%). The durations of response were 1.1, 1.5, 1.7, 1.9, 3.4, and 4.6 months. The estimated median survival time was 7.4 months (95% CI, 5.1-9.7 months). Grade 3 or 4 toxicities were not observed. Grade 1 to 2 leukopenia, anemia, and thrombocytopenia were seen in 5 of 68 cycles, 16 of 68, and 2 of 68, respectively. Nonhematologic toxicities included grade 1 to 2 nausea or vomiting (30 of 68 cycles), nephrotoxicity (27 of 68), and hepatotoxicity (13 of 68). SKI 2053R showed a modest antitumor activity with limited toxicities in patients with ED SCLC. Further clinical trials are warranted in SCLC with a higher dose of SKI 2053R.

Adult↗

PubMed1999

Myelodysplastic syndrome that progressed to acute myelomonocytic leukemia with eosinophilia showing peculiar chromosomal abnormality: a case report.

Myelodysplastic syndrome is a closely related group of acquired bone marrow disorders characterized by ineffective and dysplastic hematopoiesis. These clonal disorders frequently progress to acute leukemia. Acute myelomonocytic leukemia with eosinophilia is characterized by an increase in abnormal eosinophils in the bone marrow, relatively good clinical course and inv (16) chromosomal abnormality. We experienced one case of refractory anemia with excess blasts which progressed to refractory anemia with excess blasts in transformation and finally to acute myelomonocytic leukemia with eosinophilia showing peculiar chromosomal abnormalities of der (1;7).

Adult↗

PubMed1999

Clinical analysis of 12 Korean Lambert-Eaton myasthenic syndrome (LEMS) patients.

The Lambert-Eaton myasthenic syndrome (LEMS) heralds the occurrence of malignancy, especially small-cell lung cancer (SCLC), but it can also occur in the absence of cancer. Twelve patients were diagnosed as LEMS by clinical features and the classical electrophysiological triad, which includes a low amplitude of compound muscle action potentials (CMAP), decremental responses on low-rate stimulation, and incremental responses on high-rate stimulation on the repetitive nerve stimulation (RNS) test. There were 6 male and 6 female patients, ranging in age from 49 to 66 years. Malignancy(all were SCLC) was found in 7 patients. Males predominantly expressed the paraneoplastic form; whereas the primary autoimmune form was found only in women, who showed a good response to corticosteroid treatment. The neurological features were similar in both groups: proximal lower limb weakness, depressed muscle stretch reflexes, and dryness of mouth in nearly all patients. Bulbar dysfunction and limb paresthesia were a little more frequent in the paraneoplastic form. In RNS tests, the characteristic electrophysiological abnormalities were found in all patients and were more profound in the paraneoplastic form. We concluded that LEMS is commonly associated with malignancy, especially SCLC, but it should also be stressed that there are many female LEMS patients who do not harbor any malignancy at all, and that other treatment strategies such as immunotherapy should be considered for these patients.

Aged↗

PubMed1999

Successful treatment with ganciclovir for cytomegalovirus duodenitis following allogenic bone marrow transplantation.

Cytomegalovirus(CMV) disease is a major cause of morbidity and mortality in immunocompromised patients. CMV enteritis should be considered when nausea and vomiting continue 3 to 4 weeks after bone marrow transplantation(BMT). The treatment of CMV enteritis is not well established. We report a CMV duodenitis patient following allogenic bone marrow transplantation. The patient had prolonged nausea and vomiting for 5 weeks after bone marrow transplantation and CMV duodenitis was diagnosed by the gastroduodenoscopic mucosal biopsy which showed cytomegalic cells. Ganciclovir treatment for 3 weeks resulted in the resolution of symptoms and promoted healing of the lesion. The patient was free of CMV infection until 288 days after allogenic BMT without maintenance ganciclovir treatment.

Adult↗

PubMed1998

Potentiated glucose deprivation-induced death of astrocytes after induction of iNOS.

Astrocytes play an essential role in the maintenance of normal neuronal function. Here we report that pretreatment of interferon-gamma (IFN-gamma) and lipopolysaccharides (LPS) made murine astrocytes highly vulnerable to glucose deprivation-induced death. Neither 12-hr glucose deprivation nor 2-day treatment with IFN-gamma (100 U/ml) and LPS (1 microg/ml) altered the viability of astrocytes. However, significant death of IFN-gamma/LPS-treated astrocytes was observed after 4-hr glucose deprivation. This augmented death was mimicked by the nitric oxide releasing reagent 3-morpholinosydnonimine and was in part prevented by the nitric oxide synthase inhibitor NG-nitroarginine. The data indicate that immunostimulated astrocytes can undergo suicidal death during glucose deprivation through the expression of inducible nitric oxide synthase.

Animals↗

PubMed1998

Proliferation-dependent vulnerability of glucose-deprived astrocytes to nitric oxide-induced cytotoxicity.

The present study investigated the vulnerability of glucose-deprived astrocytes to nitric oxide (NO)-induced cytotoxicity. Primary murine cortical astrocyte cultures of different ages were deprived of glucose in the presence of the NO-releasing reagent 3-morpholinosydnonimine. Glucose-deprived astrocytes displayed an age-dependent vulnerability to NO cytotoxicity. However, this difference in vulnerability with age was found to be dependent on initial plating density. The augmented deaths of astrocyte cultures were consistent with the [3H]thymidine incorporation pattern. Thus, rapidly dividing astrocytes were much more susceptible to NO cytotoxicity under glucose-deprived conditions. The data indicate that the vulnerability of glucose-deprived astrocytes to NO cytotoxicity depends on the proliferative state rather than age in vitro.

Analysis of Variance↗

PubMed1998

Potentiation of N-methyl-D-aspartate-mediated neurotoxicity by immunostimulated murine microglia.

Microglia have been shown to be immunostimulated by inflammatory cytokines and produce a number of toxic mediators. Here we report that immunostimulated microglia can synergistically enhance the N-methyl-D-aspartate (NMDA) receptor-mediated excitotoxicity in rat cerebellar granule cells (CGC) in culture. Neurotoxicity was assessed by morphological examination and by measuring the release of lactate dehydrogenase and DNA fragmentation. Cultured microglia were immunostimulated by interferon-gamma (200 U/ml) and lipopolysaccharides (10 microg/ml) and one or two days later they were used for co-culture with CGC. Co-culture of CGC with immunostimulated microglia resulted in a remarkable enhancement of the NMDA receptor-mediated death of CGC. This enhanced neurotoxicity was mimicked by the nitric oxide releaser 3-morpholinosydnonimine (SIN-1) or S-nitroso-N-acetylpenicillamine (SNAP). Superoxide dismutase and catalase, which stabilise NO by removing superoxide anion, ameliorated the potentiation of the NMDA-mediated death of CGC in co-culture with immunostimulated microglia, implying that reactions of NO with superoxide to form peroxynitrite can be implicated in the potentiated neurotoxicity. Our data indicate that immunostimulated microglia, which may involve in various neuropathologies, potentiate the NMDA receptor-mediated excitotoxicity in part through the expression of inducible nitric oxide synthase.

Animals↗

PubMed1998

Microvascular anastomosis with minimal suture and fibrin glue: experimental and clinical study.

A comparative study was undertaken to evaluate a new microvascular anastomosis technique utilizing only four sutures placed 90 degrees apart and sealed with fibrin glue, in contrast to the conventional method of eight sutures as a control. The two methods were compared in regard to patency rates, time needed for vascular anastomosis, and microscopic evaluation. Postoperative patency rates were 100% and 85% with the fibrin glue technique compared with 100% and 90% with the conventional technique immediately postoperative and 2 weeks postoperative, respectively. Less time was consumed with the fibrin glue technique, which took 16 minutes, compared with the conventional technique, which took 21 minutes. Microscopically, re-endothelization was complete, with a smooth and less injured inner lining and also with less inflammatory response in the fibrin glue technique compared with the conventional technique. We applied this new technique to clinical cases of 17 digit replantations and one free flap. All cases survived completely except for one toe replantation case, which was severely crushed at the time of injury.

Adult↗

PubMed1998

Purification and characterization of a male-specific protein in the hemolymph of the wax moth, Galleria mellonella L.

A male-specific protein (MSP) present only in males was identified from the hemolymph of the wax moth, Galleria mellonella L., by polyacrylamide gel electrophoresis (PAGE) and purified by anion-exchange chromatography. MSP has a native molecular mass of 55 kDa and consists of two 27-kDa subunits. An isoelectric point of MSP was measured to be approximately 5.8. MSP is a glycoprotein that contains 1.7% carbohydrate. The compositional analysis of carbohydrate component indicated a predominance of fructose and glucose. MSP also contains large amounts of asparagine, aspartic acid, glutamine, glutamic acid, and lysine but small amounts of tyrosine, methionine, and tryptophan. Western blot analysis of the hemolymph of each developmental stage indicated that MSP is present in the hemolymph of 8-day-old pupa and adult. Also, results from Western blotting indicated that MSP is not present in the tissues of larvae and of female adults but appears in the fat body of male pupae and adult and testis of adult. The fat body and testis of male pupae and adult were cultured in vitro to trace the place and time of MSP synthesis. The fat body began to synthesize MSP in late pupae and showed active synthesis during the adult stage. The distribution of MSP in the testis was observed by electron microscopic immunogold labeling, using the antibody against MSP. MSP is present between the germinal cysts and is taken up through the basal surface of the seminiferous tubular epithelium.

Amino Acids↗

PubMed1998

Antitumor activity of the aqueous-alcoholic extracts from unripe cotton ball of Gossypium indicum.

The present study investigated the antitumor activity of the aqueous-alcoholic extracts from unripe cotton balls of Gossypium indicum. An Exposure of murine B16 melanoma and L1210 lymphoma cells to the extracts resulted in their severe deaths in time- and concentration-dependent manners. Of the extracts, hydrophilic fractions were most efficacious for the antitumor activity and found to contain certain amounts of catechin and its derivatives. The hydrophilic extract fraction C36B2-8 had approximately 10 times more cytotoxic effects on B12 and L1210 cells than on isolated murine thymocytes. High concentrations (> 150 micrograms/ml) of C 36B3-8 mainly induced necrotic cell death. At low concentrations (< 100 micrograms/ml), however, C 36B3-8 induced not only necrosis but also apoptosis of the two tumor cell lines, which was proved by the TUNEL staining and DNA fragmentation techniques. The data indicate that certain ingredients of the cotton ball extract of G. indicum have an antitumor activity.

Animals↗

PubMed1998

Mutational abrogation of the PTEN/MMAC1 gene in gastrointestinal polyps in patients with Cowden disease.

BACKGROUND & AIMS: To understand the molecular etiology of Cowden disease-associated gastrointestinal polyps, we analyzed the mutational status of PTEN/MMAC1, a recently identified Cowden disease gene located at 10q23, in gastric hamartomas, colonic adenoma, and juvenile polyps of 3 patients with Cowden disease. METHODS: Messenger RNA expression, gene deletion, and sequence alteration of PTEN/MMAC1 were evaluated by quantitative polymerease chain reaction (PCR), PCR-single-strand conformation polymorphism, and sequencing analysis. RESULTS: Germline missense mutation at codon 289 (AAA to GAA, Lys to Glu) and deletion of the wild-type allele were detected in the polyps of 2 patients with Cowden disease in the same family. Germline allelic deletion and transcriptional silencing of the remaining allele, probably caused by abnormal methylation, were also observed in a gastric hamartoma of 1 patient. CONCLUSIONS: The germline mutation and alteration of the remaining allele observed in this study strongly support that PTEN/MMAC1 functions as a tumor suppressor in Cowden disease. This study is the first to show that the mutational abrogation of PTEN/MMAC1 plays a causal role in the genesis of gastrointestinal polyps in Cowden disease, providing molecular genetic evidence that colonic adenoma, juvenile polyp, and gastric hamartoma could be included in the manifestations of Cowden disease.

Adolescent↗

PubMed1998

Postembryonic development of leucokinin-like immunoreactive neurons in the moth Spodoptera litura.

Antiserum to leucokinin I, a neuropeptide originally isolated from the cockroach Leucophaea maderae, was used for immunocytochemical labeling of neurons in the brain and ventral ganglia of the moth Spodoptera litura during postembryonic development. In the ventral ganglia, leucokinin-like immunoreactivity begins to occur in the abdominal ganglion A3 to A7 of first instar larva. One to two weakly labeled pairs of bilateral LK-LI cell bodies are located in the subesophageal ganglion of fourth to sixth instar larvae and in the abdominal ganglia A1 to A7 of second to sixth instar larvae. The abdominal ganglion A1 of fourth to sixth instar larvae and A8 of sixth instar larva each contain one weakly labeled pair of median LK-LI cell bodies. Two strongly labeled pairs of bilateral LK-LI neurons are found in A3 to A7 of third to sixth instar larvae. Abdominal ganglia A1 to A8 of prepupa, pupa and adult contain one to three weakly labeled pairs of bilateral LK-LI neurons. Two strongly labeled pairs of bilateral LK-LI neurons in each of the abdominal ganglia of larva, prepupa, pupa and adult send axons to the neuropil, and then each axon bifurcates into two axonal branches. Theses axonal branches from two bundles. From each of the two pairs of neurons an axon exits through the posterior ventral nerve (N2) which runs to the transverse nerve of the next posterior segment. In larval brains, 2-16 pairs of bilateral LK-LI cell bodies can be found together with LK-LI processes in the central neuropil. The larval brains show large changes in the number of LK-LI neurons throughout postembryonic development. The number of LK-LI cell bodies are reduced in number from sixth instar larval brain. Therefore, prepupal, pupal and adult brains contain a smaller number of LK-LI cell bodies. Two pairs of LK-LI median neurosecretory cells located immediately beside the pars intercerebralis in larval brains increase to three pairs in the 7-day-old pupal brain. In the adult, however, LK-LI median neurosecretory cells decrease to one pair.

Animals↗

PubMed1998

Relevance of proteins C and S, antithrombin III, von Willebrand factor, and factor VIII for the development of hepatic veno-occlusive disease in patients undergoing allogeneic bone marrow transplantation: a prospective study.

Factors that enhance hypercoagulability following BMT may have a pathogenetic role in VOD. To investigate the relevance of hemostatic parameters for the development of VOD, we prospectively measured protein C, protein S, antithrombin III (AT III), von Willebrand factor, and factor VIII in 50 consecutive patients undergoing allogeneic BMT. Each parameter was determined before conditioning, on day 0 of BMT and weekly for 3 weeks, and patients were monitored prospectively for the occurrence of VOD. VOD occurred in 26 patients at median post-BMT day 8.5 (range, day -2 to 17). Thirteen patients had mild, 10 had moderate and three had severe VOD. No coagulation parameters were significantly different at the baseline or on day 0 of BMT between patients with no/mild VOD and moderate to severe VOD. On day 7 and thereafter, levels of protein C and AT III were significantly lower in patients with moderate to severe VOD when compared to patients with no/mild VOD. Levels of protein C and AT III decreased before the clinical onset of VOD in patients with moderate to severe VOD. Early post-BMT reduction of these parameters may indicate the development of moderate to severe VOD.

Adolescent↗