Search PubMed⌕ Search

Biomedical subjects

J W Kim

Publications and source records attributed to J W Kim.

At least 163 records · Page 9Linked to original sources
PubMed2000

Chronic exposure of hydroxyapatite orbital implants: cilia implantation and epithelial downgrowth.

PURPOSE: To describe previously unreported histologic findings in two patients who developed chronic implant exposure and abscess formation within hydroxyapatite orbital implants. METHODS: Surgically removed implant specimens were processed for histopathologic examination and stained for microorganisms. Each patient's clinical course, socket appearance, and exposure management were reviewed. RESULTS: Histopathologic examination of case 1 showed a channel of necrosis leading from the anterior surface of the implant to its center. Hair shafts were discovered embedded within this channel. Histopathologic examination of the site of chronic exposure in case 2 showed epithelial ingrowth into the pores of the implant. Both spheres in this report indicated limited fibrovascular ingrowth and abscess formation. CONCLUSIONS: Chronic exposure of hydroxyapatite implants allows a portal of entry for extraneous hair shafts and also can lead to epithelial downgrowth. Both of these may be contributing factors in the development of serious implant infections.

Abscess↗
PubMed2000

Effects of beta-toxin of Staphylococcus aureus on ciliary activity of nasal epithelial cells.

OBJECTIVES: To investigate the in vitro effects of staphylococcal beta-toxin on ciliary activity and the in vivo effects on sinusitis induction. STUDY DESIGN: The in vitro effects of staphylococcal beta-toxin on ciliary activity were investigated at different concentrations and exposure times. Experimental sinusitis was induced in rabbits with application of beta-toxin and confirmed 7 days later. METHODS: Ciliated epithelial cells were taken from the maxillary sinus mucosa of 10 rabbits. Five culture dishes from each rabbit were used for the experimental group, and one culture dish from each rabbit was used for the control group. In the experimental group, ciliary beat frequency (CBF) was measured at concentrations of 0.1, 1, 2, 5 and 10 U/mL of beta-toxin using a video-computerized analysis technique, while in the control group, culture medium containing no toxin was used. CBF was measured 1, 2, 4, 6, 8, 12, 24, and 48 hours after administration of beta-toxin. To induce experimental sinusitis, 2 U/mL of beta-toxin was percutaneously applied to the maxillary sinus of 10 rabbits without occlusion of the natural ostium, while normal saline was percutaneously applied to the right-side maxillary sinus of 4 rabbits in the control group. At 7 days, mucosal membranes were taken from the inferomedial wall of the maxillary sinus for light microscopic study. RESULTS: CBF dropped significantly after an 8-hour incubation at 2, 5, and 10 U/mL of beta-toxin. No ciliary activity was observed after a 24-hour incubation at 2 and 5 U/mL and a 12-hour incubation at 10 U/mL of beta-toxin. Mucoid, purulent discharge was observed in the maxillary sinuses of the beta-toxin-applied group. Prominent epithelial disruption and infiltration of inflammatory cells into the epithelium and lamina propria were observed in the beta-toxin-applied group. CONCLUSIONS: Staphylococcal beta-toxin may reduce ciliary activity and induce sinusitis without occlusion of the natural ostium of the maxillary sinus in rabbits This study provides another animal model of sinusitis for understanding the pathogenesis of sinusitis induced by bacterial exotoxins.

Animals↗
PubMed2000

Adverse pregnancy outcome following post-chorionic villus sampling amniocentesis compared to chorionic villus sampling.

OBJECTIVE: To assess the adverse pregnancy outcome of post-chorionic villus sampling (CVS) amniocentesis and chorionic villus sampling. METHODS: Adverse pregnancy outcomes of 32 post-CVS amniocentesis cases and 264 CVS only cases were compared. The base-line characteristics were comparable in the 2 groups. RESULTS: One (3.1%) chromosomal abnormality was detected in the post-CVS amniocentesis group, compared to 5 (1.8%) in the CVS only group (p > 0.05). The fetal loss rate (spontaneous abortions and stillbirths) among continuing pregnancies was 3.2% in the post-CVS amniocentesis group and 3.5% in the CVS only group (p > 0.05). No statistically significant difference was found in the incidence of neonatal death, preterm delivery, fetal growth restriction, or congenital anomalies between the 2 groups. CONCLUSION: Adverse pregnancy outcome occurred at a similar frequency in the post-CVS amniocentesis group as in the CVS only group. Therefore, a subsequent amniocentesis after CVS can be considered as a safe procedure that does not introduce any additional adverse pregnancy outcome compared to that of CVS only.

Adult↗
PubMed2000

Heterotopic pancreas in the stomach: CT findings.

PURPOSE: To describe the computed tomographic (CT) findings of heterotopic pancreas in the stomach. MATERIALS AND METHODS: CT findings in 12 patients with heterotopic pancreas in the stomach were reviewed. Surgical resection (n = 11) or endoscopic excision (n = 1) was performed in cases of symptomatic heterotopic pancreas (n = 4), suspected submucosal tumors (n = 7), and gastric carcinoma (n = 1). Seven patients underwent helical CT with water as an oral contrast agent; five underwent nonhelical CT with water-soluble contrast material. RESULTS: Nine heterotopic pancreata were in the antrum and one each was in the body, fundus, and perigastric fat. Seven lesions were on the greater curvature aspect; five, on the lesser curvature aspect. Common CT findings were well-defined oval or round masses with smooth or serrated margins in the gastric antral wall. Four of the seven lesions in which helical CT was performed enhanced similarly to normal pancreas. Preoperatively, CT depicted 11 of the 12 lesions, but CT findings were interpreted correctly as heterotopic pancreas in only two; the remaining 10 were misinterpreted as other lesions. Atypical findings were cystic dilatation of heterotopic pancreatic duct in two, unusual location in the fundus or perigastric fat in two, and malignant transformation in one. CONCLUSION: CT findings of heterotopic pancreas in the stomach appear to be nonspecific for diagnosis, except for location.

Adult↗
PubMed2000

DNA-binding activity of the N-terminal cleavage product of poly(ADP-ribose) polymerase is required for UV mediated apoptosis.

The role of the N-terminal cleavage product of poly(ADP-ribose) polymerase (PARP) on UV mediated apoptosis was investigated in cultured HeLa cells. Ultrastructural analysis of cells expressing caspase-resistant PARP (PARP(D214A)) revealed the typical features of necrosis following UV treatment. However, cells co-expressing PARP(D214A) with the N-terminal fragment of PARP containing the DNA-binding domain underwent apoptosis instead of necrosis. In this study, we have demonstrated that the DNA-binding activity of the N-terminal fragment of PARP is important for the execution of apoptosis. Point mutations were introduced in the DNA-binding sites of the N-terminal fragment. Cells co-expressing PARP(D214A) with the mutated N-terminal fragments neither stimulated apoptosis nor prevented necrosis in response to UV irradiation. The present study proposes that the DNA-binding activity of the N-terminal fragment of PARP in UV treated cells prevents cellular ATP depletion, a mechanism by which necrotic cell death is triggered.

Apoptosis↗
PubMed2000

Zinc as a paracrine effector in pancreatic islet cell death.

Because of a huge amount of Zn2+ in secretory granules of pancreatic islet beta-cells, Zn2+ released in certain conditions might affect the function or survival of islet cells. We studied potential paracrine effects of endogenous Zn2+ on beta-cell death. Zn2+ induced insulinoma/islet cell death in a dose-dependent manner. Chelation of released endogenous Zn2+ by CaEDTA significantly decreased streptozotocin (STZ)-induced islet cell death in an in vitro culture system simulating in vivo circumstances but not in the conventional culture system. Zn2+ chelation in vivo by continuous CaEDTA infusion significantly decreased the incidence of diabetes after STZ administration. N-(6-methoxy-quinolyl)-para-toluene-sulfonamide staining revealed that Zn2+ was densely deposited in degenerating islet cells 24 h after STZ treatment, which was decreased by CaEDTA infusion. We show here that Zn2+ is not a passive element for insulin storage but an active participant in islet cell death in certain conditions, which in time might contribute to the development of diabetes in aged people.

Biological Transport↗
PubMed2000

Identification and functional characterization of the peroxisomal proliferator response element in rat GLUT2 promoter.

We identified the peroxisomal proliferator response element (PPRE) in the +68/+89 region of the rat GLUT2 gene. To identify whether the putative PPRE in the GLUT2 gene (GLUT2-PPRE) is functional, GLUT2 promoter-luciferase reporter constructs were transfected into CV-1 cells. Promoter activities were increased by coexpression of peroxisomal proliferator-activated receptor (PPAR)-gamma, retinoid X receptor (RXR)-alpha, and treatment of their ligands; troglitazone and 9-cis retinoic acid potentiated the transactivational effects. Introduction of mutations in GLUT2-PPRE resulted in loss of transactivational effects of the PPAR-gamma/RXR-alpha heterodimer. Electrophoretic mobility shift assay using nuclear extracts of CV-1 cells, which were transfected with various combinations of PPARs or RXR-alpha expression plasmids, revealed that heterodimers of PPAR-gamma and RXR-alpha preferentially bound to GLUT2-PPRE. In HIT-T15 cells, promoter activity of the rat GLUT2 gene was increased by troglitazone and 9-cis retinoic acid, and mutations of GLUT2-PPRE resulted in reduction of promoter activity. In addition, we observed increased GLUT2 transcription by troglitazone and 9-cis retinoic acid in isolated rat primary islets. These results suggested that the GLUT2-PPRE is functional and plays a significant role in gene expression of GLUT2 in pancreatic beta-cells. This is the first report identifying PPRE in a gene involved in glucose homeostasis, linking the effect of troglitazone on the regulation of insulin secretion.

Alitretinoin↗
PubMed2000

Effect of high blood flow on the expression of endothelial constitutive nitric oxide synthase in rats with femoral arteriovenous shunts.

The effect of high blood flow on the expression of endothelial nitric oxide synthase has been investigated in the femoral arteriovenous shunt (AVS) rats created by inserting U-shaped polyurethane tubes in the left femoral arteries and veins. Three days after inserting the femoral AVS, the mean aortic blood flow rate in the abdominal aorta of the AVS rats was about 2.0 times higher than that in the control rats (110.0 +/- 8.4 ml/min vs 52.7 +/- 2.7 ml/min, p < 0.001). The competitive reverse transcriptase-polymerase chain reaction (RT-PCR) data revealed that the mRNA expression level of the endothelial constitutive nitric oxide synthase (ecNOS) was increased in the aortas of the femoral AVS rats compared to that in the control rats. Western blot analysis using a monoclonal antibody against ecNOS revealed that the ecNOS protein levels were markedly increased in the aortas of femoral AVS rats, but ecNOS protein levels in aortas without endothelium were not significantly increased. Inducible nitric oxide synthase (iNOS) protein was not expressed in the aortic tissues with and without endothelium in the control rats. This iNOS expression was not increased by the high blood flow in the femoral AVS rats. These findings suggest that high blood flow could up-regulate the expression levels of ecNOS mRNA and proteins in femoral arteriovenous shunt rats.

Animals↗
PubMed2000

Cerebral hemorrhage and edema following brain biopsy in rats: significance of mean arterial blood pressure.

OBJECT: It is taken for granted that patients with hypertension are at greater risk for intracerebral hemorrhage during neurosurgical procedures than patients with normal blood pressure. The anesthesiologist, therefore, maintains mean arterial blood pressure (MABP) near the lower end of the autoregulation curve, which in patients with preexisting hypertension can be as high as 110 to 130 mm Hg. Whether patients with long-standing hypertension experience more hemorrhage than normotensive patients after brain surgery if their blood pressure is maintained at the presurgical hypertensive level is currently unknown. The authors tested this hypothesis experimentally in a rodent model. METHODS: Hemorrhage and edema in the brain after needle biopsy was measured in vivo by using three-dimensional magnetic resonance (MR) microscopy in the following groups: WKY rats, acutely hypertensive WKY rats, spontaneously hypertensive rats (SHR strain), and SHR rats treated with either sodium nitroprusside or nicardipine. Group differences were compared using Tukey's studentized range test followed by individual pairwise comparisons of groups and adjusted for multiple comparisons. There were no differences in PaCO2, pH, and body temperature among the groups. The findings in this study indicated that only acutely hypertensive WKY rats had larger volumes of hemorrhage. Chronically hypertensive SHR rats with MABPs of 130 mm Hg did not have larger hemorrhages than normotensive rats. There were no differences in edema volumes among groups. CONCLUSIONS: The brains of SHR rats with elevated systemic MABPs are probably protected against excessive hemorrhage during surgery because of greater resistance in the larger cerebral arteries and, thus, reduced cerebral intravascular pressures.

Acute Disease↗
PubMed2000

NRAMP1 gene polymorphisms in patients with rheumatoid arthritis in Koreans.

Natural resistance-associated macrophage protein 1 (Nramp1) is a genetic locus associated with innate resistance or susceptibility of murine hosts to infection with intracellular pathogens such as Salmonella, Leishmania and Mycobacterium. The human homologue of the Nramp1 gene, designated NRAMP1, has been investigated as a candidate gene for genetic susceptibility to autoimmune diseases as well as infections. This study tries to determine whether NRAMP1 polymorphisms are associated with susceptibility to rheumatoid arthritis in Koreans. The nine NRAMP1 polymorphisms (1 microsatellite, 1 variation in 3' UTR, 5 silent substitution, 2 amino acid substitution) were typed by PCR-RFLP in 74 patients with rheumatoid arthritis (RA) and 53 healthy controls in Koreans. The distribution of allele and genotype frequencies were compared between patients and controls. Three NRAMP1 polymorphisms (823C/T, D543N and 1729+55del4) were significantly associated with RA. In addition, there were significant differences in the genotype frequencies for 823C/T, D543N and 1729+ 55del4 polymorphisms between RA patients and controls. Genotypes of A/A homozygote for D543N and TGTG deletion homozygote for 1729+55del4 were only detected in the patient group. These data indicate that genetic polymorphisms of NRAMP1 might be associated with the susceptibility to rheumatoid arthritis in Koreans.

Alleles↗
PubMed2000

Activated platelets induce secretion of interleukin-1beta, monocyte chemotactic protein-1, and macrophage inflammatory protein-1alpha and surface expression of intercellular adhesion molecule-1 on cultured endothelial cells.

Atherosclerosis is an inflammatory disease. Platelet-endothelium interaction plays an important role in the pathophysiology of atherogenesis. We investigated the role of activated platelets for secretion of interleukin (IL)-1beta, monocyte chemotactic protein (MCP)-1 and macrophage inflammatory protein (MIP)-1alpha and expression of intercellular adhesion molecule (ICAM)-1 on endothelial cells. Human umbilical vein endothelial cells (HUVEC) were incubated with non-stimulated or ADP-activated platelets for 6 hr. Secretion of interleukin (IL)-1beta, MCP-1 and MIP-1alpha and surface expression of ICAM-1 were measured by ELISA and flow cytometry. In the presence of activated platelets, the secretion of IL-1beta, MCP-1, and MIP-1alpha and surface expression of ICAM-1 were significantly increased compared with non-activated platelets. The present study shows that activated platelets may contribute to expression of various inflammatory mediators on endothelial cells.

Blood Platelets↗
PubMed2000

Association of the dopamine transporter gene with Parkinson's disease in Korean patients.

Dopamine transporters (DAT) uptake neurotoxic substances such as 1-methyl-4-phenylpyridinium (MPP+) in the dopaminergic nerve terminals and may confer susceptibility to cytotoxic effects of neurotoxic substance. The association of a variable number tandem repeat polymorphism in the DAT gene with Parkinson's disease (PD) in a Korean population was studied. The 10-copy allele was the most common, accounting for 77.2% and 81.6% of alleles in PD patients and control subjects, respectively. The rare 11-copy allele was more common in the patients (odds ratio = 2.5, 95% confidence interval = 1.1-5.7, p<0.02). It is suggested that the 11-copy allele of the DAT gene may confer susceptibility to PD for some patients in Korea.

Aged↗
PubMed2000

Uterine artery Doppler velocimetry in the prediction of adverse obstetric outcomes in unexplained MSAFP elevations.

Unexplained maternal serum-fetoprotein (MSAFP) elevation has been known to be associated with adverse obstetric outcomes, however it is not sufficiently useful as a screening test. This study was undertaken to determine whether uterine artery Doppler velocimetry could define a subset of patients with an elevated MSAFP level in whom complications of pregnancy might develop. The subjects included 179 women between 26 and 28 weeks' gestation with MSAFP > or = 2.5 multiples of the median, in whom either the presence of an early diastolic notch or a resistance index 0.6 was considered as an abnormal Doppler velocimetry finding. Those subjects who displayed abnormal Doppler velocimetry findings showed an increased incidence of preeclampsia, preterm birth, IUGR, and IUFD compared to those subjects with only elevated MSAFP (p < 0.05). No differences were observed in the incidence of LBW. Positive predictive values of adverse obstetric outcomes were significantly higher in the group having both elevated MSAFP and abnormal Doppler velocimetry compared to the group with only elevated MSAFP (p < 0.05). Uterine artery Doppler velocimetry in the second trimester can improve the value of unexplained MSAFP elevation in the prediction of adverse obstetric outcomes.

Adult↗
PubMed2000

Development of a speciated, hourly, and gridded air pollutants emission modeling system--a case study on the precursors of photochemical smog in the Seoul metropolitan area, Korea.

A speciated, hourly, and gridded air pollutants emission modeling system (SHEMS) was developed and applied in predicting hourly nitrogen dioxide (NO2) and ozone (O3) levels in the Seoul Metropolitan Area (SMA). The primary goal of the SHEMS was to produce a systemized emission inventory for air pollutants including ozone precursors for modeling air quality in urban areas. The SHEMS is principally composed of three parts: (1) a pre-processor to process emission factors, activity levels, and spatial and temporal information using a geographical information system; (2) an emission model for each source type; and (3) a post-processor to produce report and input data for air quality models through database modeling. The source categories in SHEMS are point, area, mobile, natural, and other sources such as fugitive emissions. The emission database produced by SHEMS contains 22 inventoried compounds: sulfur dioxide, NO2, carbon monoxide, and 19 speciated volatile organic compounds. To validate SHEMS, the emission data were tested with the Urban Airshed Model to predict NO2 and O3 concentrations in the SMA during selected episode days in 1994. The results turned out to be reliable in describing temporal variation and spatial distribution of those pollutants.

Air Pollutants↗
PubMed2000

Genetic resources: an annotated bibliography of internet and other resources.

The Internet has caused a major boom in the field of genetics. Internet use among the public and health care professionals continues to rise, but caution must be exercised when searching for information. This article presents some guidelines for determining good web sites, then follows with a compilation of Internet and other relevant genetics resources.

Genetic Diseases, Inborn↗