Biomedical subjects

K W Kim

Publications and source records attributed to K W Kim.

At least 145 records · Page 8Linked to original sources

PubMed1999

Inhibition of initiation of simian virus 40 DNA replication in vitro by the ursodeoxycholic acid and its derivatives.

In this study, the effects of the ursodeoxycholic acid (UDCA), and its derivatives, on DNA replication were examined using simian virus (SV40) DNA replication in vitro. We found that UDCA and its derivatives inhibited SV40 DNA replication, and predominantly inhibited the initiation stage of DNA replication. UDCA and its derivatives inhibited the DNA cleavage by topoisomerase I (topo I). Among them, HS-1183 significantly reduced the activity of topo I. UDCA, at 100 microM, significantly reduced polymerase alpha-primase (pol alpha-primase) activity, but HS-1030 and HS-1183 showed a weak inhibitory effect. The ssDNA binding activity of replication protein A (RPA) was little affected by UDCA and HS-1030, but was weakly inhibited by HS-1183. Based on their properties, we suggest that UDCA and its derivatives might inhibit some molecules that is required to establish replication forks during the initiation reaction and their cytotoxicity might be related to the inhibitory effect they have on this fundamental cellular process.

Antineoplastic Agents↗

PubMed1999

Sphingosine 1-phosphate induces angiogenesis: its angiogenic action and signaling mechanism in human umbilical vein endothelial cells.

Sphingosine 1-phosphate (S1P) is a bioactive sphingolipid metabolite abundantly stored in platelets and released upon platelet activation. Recently, S1P has been postulated for its potential roles in angiogenesis. In this study, we provided several lines of evidence showing that S1P has angiogenic activity. In vitro, S1P stimulated DNA synthesis and chemotactic motility of human umbilical vein endothelial cells (HUVECs) in a dose-dependent manner, reaching a near maximum at 1 microM. S1P also significantly induced tube formation of HUVECs on Matrigel. Matrigel plug assay in mice revealed that S1P promotes angiogenesis in vivo. In addition, exposure of HUVECs to S1P led to rapid activation of extracellular signal-regulated kinases (ERKs) and p38 mitogen-activated protein kinase (p38 MAPK) in a pertussis toxin (PTX)-sensitive manner. Notably, HUVEC migration and tube formation in response to S1P were completely blocked by pretreatment with PTX. Further, the MEK inhibitor U0126 markedly inhibited S1P-induced tube formation but S1P-induced migration was not affected by inhibition of ERK and p38 MAPK. Taken together, these results indicate that S1P induces angiogenesis predominantly via G(i) protein-coupled receptors in endothelial cells and suggest that S1P may act as an important modulator of platelet-induced angiogenesis.

Animals↗

PubMed1999

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↗

PubMed1999

Role of Ras/ERK-dependent pathway in the erythroid differentiation of K562 cells.

The chronic myelogenous leukemic K562 cell line carrying Bcr-Abl tyrosine kinase is considered as pluripotent hematopoietic progenitor cells expressing markers for erythroid, granulocytic, monocytic, and megakaryocytic lineages. Here we investigated the signaling modulations required for induction of erythroid differentiation of K562 cells. When the K562 cells were treated with herbimycin A (an inhibitor of protein tyrosine kinase), ras antisense oligonucleotide, and PD98059 (a specific inhibitor of MEK), inhibition of ERK/MAPK activity and cell growth, and induction of erythroid differentiation were observed. The ras mutant, pZIPRas61leu-transfected cells, K562-Ras61leu, have shown a markedly decreased cell proliferation rate with approximately 2-fold doubling time, compared with the parental K562 cells, and about 60% of these cells have shown the phenotype of erythroid differentiation. In addition, herbimycin A inhibited the growth rate and increased the erythroid differentiation, but did not affect the elevated activity of ERK/MAPK in the K562-Ras61leu cells. On the other hand, effects of PD98059 on the growth and differentiation of K562-Ras61leu cells were biphasic. At low concentration of PD98059, which inhibited the elevated activity of ERK/MAPK to the level of parental cells, the growth rate increased and the erythroid differentiation decreased slightly, and at high concentration of PD98059, which inhibited the elevated activity of ERK/MAPK below that of the parental cells, the growth rate turned down and the erythroid differentiation was restored to the untreated control level. Taken together, these results suggest that an appropriate activity of ERK/MAPK is required to maintain the rapid growth and transformed phenotype of K562 cells.

Androstadienes↗

PubMed1999

Downregulation of telomerase in rat during the aging process.

Telomerase is an RNA-dependent DNA polymerase that maintains the tandem arrays of telomeric repeats at the eukaryotic chromosome ends. Because of its ability to replenish lost telomeric sequences, telomerase is thought to be required for cell proliferation. At present, very little information on the role of telomerase in aging is available. In the present study, we tested the telomerase activity of Fischer 344 rat testis and liver at 6, 12, 18 and 24 months of age. As the testis is an androgen-dependent tissue, we also investigated the changes of testosterone and mRNA levels of androgen receptor in this tissue. Our results show that the telomerase activity of Fischer 344 rat testis significantly reduced at 24 months of age compared to 6 months of age, and that the mRNA level of telomerase protein component 1 (TLP-1) show a corresponding decrease with the telomerase activity. Interestingly, this down-regulation was not observed in the liver. The testosterone level in testis increased until 18 months of age, but reduced by 50% at 24 months of age. Our conclusions are that the telomerase activity is age-dependent and its change is a tissue-specific phenomenon.

Aging↗

PubMed1999

Volumetric change of the graft bone after intertransverse fusion.

STUDY DESIGN: Patients in whom good intertransverse fusion had been achieved were selected for the volumetric study of the fusion mass using sequential computed tomography scans. OBJECTIVES: To assess the natural volumetric change of intertransverse fusion mass and the effect of the disease entity and spinal instrumentation on the fusion mass volume. SUMMARY OF BACKGROUND DATA: The magnitude of volumetric change of the graft bone after intertransverse fusion is still inconclusive. METHODS: Fifteen adult patients who underwent decompression surgery with single-level lumbar and lumbosacral intertransverse fusion were selected for this study. Preoperative diagnoses were degenerative spondylolisthesis in nine patients and isthmic spondylolisthesis in six. Seven of the 15 patients received pedicle screw fixation. They were categorized into two major groups: 1) instrumented and noninstrumented groups and 2) isthmic and degenerative groups. To assess the volumetric change of the graft bone, sequential computed tomography scans were obtained 2 weeks after surgery and again 18 months after surgery. RESULTS: The overall initial mean graft volume was 6251 mm3, which decreased to 2842 mm3 by 18 months after surgery (P < 0.001). The overall mean volume loss between the two periods was 54.8% of the initial graft volume. Although there was no significant difference in the mean graft volume between the groups at either 2 weeks or 18 months after surgery (P > 0.05 in all comparisons), the mean graft volume in each group decreased significantly during the observation period (P < 0.01 in all comparisons). There was no significant difference in the mean volume loss or in the ratio of residual volume to the initial graft volume between the groups during the study period (P > 0.05 in all comparisons). The initial graft volume correlated positively with the graft volume at 18 months after surgery (r = 0.612, P < 0.01) and volume loss (r = 0.949, P < 0.01), but negatively with the residual volume ratio (r = -0.507, P < 0.01). CONCLUSIONS: These results showed that more than one half of the initial graft bone volume was being absorbed during the consolidation processes of the graft bone, and that the volume loss during the period was not significantly affected by the spinal instrumentation or by the disease entity. It was also found that the greater the amount of the initial graft bone, the larger the fusion mass at 18 months after surgery. The volume loss, however, increased proportionally to an increase in the initial graft bone volume. The efficiency (ratio of residual volume to the initial graft volume) of the intertransverse fusion also tended to decline as the initial graft volume increased.

Adult↗

PubMed1999

Apoptosis of pancreatic beta-cells detected in accelerated diabetes of NOD mice: no role of Fas-Fas ligand interaction in autoimmune diabetes.

Autoreactive T lymphocytes probably cause pancreatic beta-cell death by inducing apoptosis. To visualize apoptotic beta-cells in vivo, we accelerated diabetes of NOD mice with cyclophosphamide (CY) or adoptive transfer. We also studied whether Fas-mediated apoptosis is involved in the development of diabetes by administrating anti-Fas ligand (FasL) Ab and by grafting Fas-deficient neonatal pancreas from NOD-lpr/lpr mice. Apoptotic cells were clearly shown 8 days after CY treatment. Beta-cell apoptosis was also observed after adoptive transfer but in a different kinetic pattern. Anti-FasL Ab administration failed to inhibit diabetes after CY treatment or adoptive transfer, while it inhibited Con A-induced hepatitis. Fas-deficient neonatal pancreata were destroyed by lymphocytic infiltration in diabetic NOD mice. Our results clearly demonstrate apoptosis of beta-cells in accelerated diabetes and indicate that Fas-FasL interaction is not involved in diabetes of NOD mice, contrary to the previous reports.

Animals↗

PubMed1999

Regional difference of ROS generation, lipid peroxidation, and antioxidant enzyme activity in rat brain and their dietary modulation.

One of the potential causes of age-related neuronal damage can be reactive oxygen species (ROS), as the brain is particularly sensitive to oxidative damage. In the present study, we investigated the effects of aging and dietary restriction (DR) on ROS generation, lipid peroxidation, and antioxidant enzymes in cerebrum, hippocampus, and cerebellum of 6-, 12-, 18-, and 24-month-old rats. ROS generation significantly increased with age in cerebrum of ad libitum (AL) rats. However, no significant age-difference was observed in hippocampus and cerebellum. DR significantly decreased ROS generation in cerebrum and cerebellum at 24-months. On the other hand, the increased lipid peroxidation of AL rats during aging was significantly reduced by DR in all regions. Our results further showed that catalase activity decreased with age in cerebellum of AL rats, which was reversed by DR, although SOD activity had little change by aging and DR in all regions. In a similar way, glutathione (GSH) peroxidase activity increased with age in cerebrum of AL rats, while DR suppressed it at 24-months. These data further support the evidence that the vulnerability to oxidative stress in the brain is region-specific.

Aging↗

PubMed1999

Dietary modulation of prostanoid synthesis in the aging process: role of cyclooxygenase-2.

To investigate the role of cyclooxygenase (COX) as a mediator for prostaglandin synthesis in relation to generation of reactive oxidant species (ROS), we quantitated the COX-derived ROS generation and the gene expression of COX-2, an inducible form of COX in aged kidney. In addition, the modulation by dietary restriction was investigated. COX-derived ROS generation increased with age in ad libitum (AL) rats, but dietary restriction (DR) suppressed the level. The amounts of COX-2 protein and mRNA increased with age in AL rats but maintained at low levels in DR group. It was found that the binding characteristics of a nuclear transcription factor, NF-kappaB were altered by aging. The binding activity of NF-kappaB in aged kidney was significantly enhanced with the corresponding increase in mRNA and protein levels. These increases were closely in parallel to the increased ROS generation and gene expression of COX-2. The COX activity shown by NF-kappaB activation and the ROS generation by COX-mediated process were all modulated by DR. Our results suggest that the upregulation of COX-2 during aging may play an important role in many age-related diseases associated with aging process. And this upregulation was attenuated by DR. We propose that the modulation of the redox-sensitive transcription factor may well be a part of the mechanisms underpinning the anti-oxidative action of DR.

Aging↗

PubMed1999

A novel angiogenic factor derived from Aloe vera gel: beta-sitosterol, a plant sterol.

Aloe vera gel has a beneficial effect on wound healing. Because angiogenesis is an essential process in wound healing, we hypothesized that Aloe vera gel might contain potent angiogenic compounds. Here we demonstrate that Aloe vera gel and its extracts are angiogenic on the chorioallantoic membrane (CAM) of chick embryo. Out of the three compounds purified from the final fraction of Aloe vera gel, beta-sitosterol showed a potent angiogenic activity in the CAM assay. In the presence of heparin, beta-sitosterol stimulated neovascularization in the mouse Matrigel plug assay and the motility of human umbilical vein endothelial cells in an in vitro wound migration assay. Thus beta-sitosterol is a novel plant-derived angiogenic factor which may have potential pharmaceutical applications for the management of chronic wounds.

Journal Article↗

PubMed1999

Induction of membrane-type matrix metalloproteinase-1 stimulates angiogenic activities of bovine aortic endothelial cells.

Matrix metalloproteinases (MMPs) have been reported to play critical roles in endothelial cell migration and matrix remodeling during the angiogenic process. Among these MMPs, membrane-type MMP-1 (MT1-MMP) is an important molecule that can trigger the invasion of tumor cells by activating MMP-2 on their plasma membrane. However, the precise involvement of MT1-MMP in the angiogenic process has not been determined. To investigate the roles of the MT1-MMP by the matrix remodeling of endothelial cells, MT1-MMP expression vector was transfected into bovine aortic endothelial cells (BAECs). Increased expression of MT1-MMP in BAECs enhanced the activation of MMP-2, invasion and migration of BAECs. Moreover, the capacity of tube formation was increased in MT1-MMP transfectants. However, cotransfection with antisense MT1-MMP expression vector abolished the effects of MT1-MMP overexpression. These observations indicate that MT1-MMP is involved in the angiogenic process of endothelial cells in vitro.

Journal Article↗

PubMed1999

Carbachol-induced sustained tonic contraction of rat detrusor muscle.

OBJECTIVE: To investigate the underlying contractile mechanism of the sustained tonic contraction (SuTC) induced by repetitive carbachol application in rat detrusor muscles. MATERIALS AND METHODS: Longitudinal muscle strips with no mucosa were obtained from the anterior wall of the urinary bladder in 12-week-old Sprague-Dawley rats. Carbachol (5 micromol/L) was applied repetitively to induce SuTC. The carbachol-induced SuTC was assessed in the presence of various Ca2+-channel blockers and drugs affecting intracellular Ca2+ concentration. RESULTS: The first application of carbachol elicited a large phasic contraction followed by a tonic contraction (TC); the carbachol-induced contraction was completely reversed by washing out the solution. However, the initial phasic contraction was not reproduced after a second or further application of carbachol. There was consistently only a SuTC with no phasic contraction. The amplitude of the SuTC was 85% of the TC induced by the first carbachol application. The application of atropine (1 micromol/L) to the bath completely blocked SuTC. The carbachol-induced SuTC was insensitive to nicardipine (5 micromol/L) and extracellular polyvalent cations (1 mmol/L, La3+, Co2+, Cd2+, Ni2+ ). Moreover, a similar SuTC was induced even after the complete elimination of extracellular Ca2+ by adding 2 mmol/L EGTA to the Ca2+-free Tyrode solution. To exclude intracellular Ca2+ sources related to the sarcoplasmic reticulum (SR), the effects of SR Ca2+ pump inhibitors, cyclopiazonic acid (CPA, 10 micromol/L) and thapsigargin (0.5 micromol/L) were tested. The carbachol-induced SuTC was insensitive to pretreatment with CPA and/or thapsigargin. To deplete the ryanodine-sensitive Ca2+ pool, muscle strips were repetitively stimulated with caffeine (10 mmol/L) in the presence of 10 micromol/L ryanodine, which did not affect the carbachol-induced SuTC. CONCLUSIONS: Although the characteristics of the carbachol-induced SuTC have not been defined, these results show that a significant proportion of the carbachol-induced contraction in rats is contributed by the SuTC, which is present even in the complete absence of external Ca2+. The SuTC was not affected by limiting the contributions of internal Ca2+ sources. This suggests that the SuTC in rat bladders is unrelated to known Ca2+ mobilization mechanisms.

Animals↗

PubMed1999

alpha-Glucosidase inhibitors from Commelina communis.

A methanolic extract of Commelina communis showed potent inhibitory activity against alpha-glucosidase. One pyrrolidine alkaloid, 2,5-dihydroxymethyl-3,4-dihydroxypyrrolidine (DMDP, 1) and four piperidine alkaloids, 1-deoxymannojirimycin (2), 1-deoxynojirimycin (3), alpha-homonojirimycin (4) and 7-O-beta-D-glucopyranosyl alpha-homonojirimycin (5) were isolated by bioassay-directed fractionation and separation. These compounds have been identified for the first time from Commelina communis, supporting the pharmacological basis of this plant that has been used as a traditional herbal medicine for the treatment of diabetes.

Alkaloids↗

PubMed1999

Role of Ca(2+)-dependent K+ channels in erythrocyte lysate-induced contraction of rabbit cerebral artery.

K+ channel openers may be useful in the treatment of cerebral vasospasm following subarachnoid hemorrhage. However, the role of Ca(2+)-dependent K+ channel (KCa) openers in cerebral vasospasm remain unclear. This study was undertaken to examine the role of KCa in hemolysate-induced contraction of rabbit cerebral and peripheral arteries: 1. Iberiotoxin (IBX), a selective KCa channel blocker, produced more pronounced contraction in basilar than in those of carotid or femoral arteries, indicating KCa channels are important regulating factors in cerebral arteries; 2. NS1619, a selective KCa channel opener, abolished the contraction of basilar artery to erythrocyte lysate, a causative agent for cerebral vasospasm; 3. In rabbit basilar artery, NS1619 relaxed the contractions to IBX, erythrocyte lysate and KCl (20 and 60 mM), indicating that NS1619, besides opening KCa channels, possesses other vasodilating actions. We conclude that KCa channels are important factors in the regulation of cerebral vascular tension and KCa channel opener NS1619 may have dual relaxant actions in cerebral arteries.

Animals↗

PubMed1999

Detection of RET/PTC oncogene rearrangements in Korean papillary thyroid carcinomas.

The prevalence of RET/PTC rearrangement in papillary thyroid carcinomas has been found to vary widely in different populations. Recent studies, however, have reported no significant geographical difference between Asian and Western countries. In addition, there are some disagreements about the correlation of RET/PTC expression with clinical aggressiveness. We have performed this study in order to examine the prevalence of RET/PTC-1, RET/PTC-2, and RET/PTC-3 rearrangements in Korean papillary thyroid carcinomas, and to ascertain its clinical relevance. Thyroid tumors from 31 patients histologically confirmed to be papillary carcinomas were included in this study. To find rearrangements, we utilized reverse transcription-polymerase chain reaction (RT-PCR) and automated direct sequencing. Initial and follow-up clinical data were obtained from the patients' medical records. We identified two tumors containing RET/PTC-1 (2/31, 6.5%) and two containing RET/PTC-2 (2/31, 6.5%). However, we could not find RET/PTC-3 rearrangement in any patients (0/31). In conclusion, we report RET/PTC rearrangements in 4 of 31, (12.9%) Korean patients with papillary thyroid carcinomas, a higher prevalence than previously reported in this population.

Adult↗

PubMed1999

Association between apolipoprotein E polymorphism and macroalbuminuria in patients with non-insulin dependent diabetes mellitus.

OBJECTIVES: Apolipoprotein E (apo E) is known to play an important role in lipoprotein metabolism through its ability to bind to the receptors as a ligand. Three different apo E alleles (epsilon2, epsilon3 and epsilon4) produce six apo E genotypes (epsilon2/2, epsilon2/3, epsilon2/4, epsilon3/3, epsilon3/4 and epsilon4/4). The objective of this study was to investigate an association between apo E gene polymorphism and macroalbuminuria in 167 Korean patients with non-insulin dependent diabetes mellitus (NIDDM). METHODS: The patients in the macroalbuminuria group (n = 74) represent those in whom 24 h urinary albumin excretion was above 300 mg. The patients in the normoalbuminuria group (n = 93) represent those in whom 24 h urinary albumin excretion was below 30 mg and serum creatinine levels were less than 1.2 mg/dl. The duration of diabetes in all patients was at least 8 years. RESULTS: There were no significant differences in terms of age, sex, body mass index, HbA1c, total cholesterol, triglyceride, HDL-cholesterol and LDL-cholesterol between the two groups. In the macroalbuminuria group, the distribution of apo E genotypes revealed epsilon2/2 2 (2.7%), epsilon2/3 14 (18.9%), epsilon2/4 0 (0%), epsilon3/3 47 (63.5%), epsilon3/4 11 (14.9%) and epsilon4/4 0 (0%). In the normoalbuminuria group, the distribution of apo E genotypes revealed epsilon2/2 0 (0%), epsilon2/3 7 (7.5%), epsilon2/4 1 (1.1%), epsilon3/3 72 (77.4%), epsilon3/4 12 (12.9%) and epsilon4/4 1 (1.1%). There was no significant difference in the distribution of apo E genotypes between the two groups. However, there was a significant difference in the allele frequencies, epsilon2 frequency was significantly higher in macroalbuminuria group compared to normoalbuminuria group (12.2% vs 4.3%, P<0.05). Also, we compared apo E carrier frequencies between the two groups. Epsilon2 carrier frequency was significantly higher in macroalbuminuria group compared to normoalbuminuria group (21.6% vs 7.6%, P<0.05). In each group, there was no significant difference in the degree of lipid abnormalities between apo epsilon2 carrier (epsilon2/2, epsilon2/3 genotypes), epsilon3 carrier (epsilon3/3 genotype) and epsilon4 carrier (epsilon3/4, epsilon4/4 genotype). CONCLUSION: Apo epsilon2 allele and epsilon2 carrier frequencies were significantly higher in macroalbuminuria group. These results suggest that epsilon2 allele may be associated with the development of clinical albuminuria in Korean patients with NIDDM.

Aged↗

PubMed1999

Fate of the facet joints after instrumented intertransverse process fusion.

A success or failure of an intertransverse process fusion has been determined by the fusion status of the intertransverse fusion mass alone, and little consideration has been given to the fusion status of the facet joint. The purpose of this study was to assess the fusion status of the facet joints at the fusion level and its impact on the overall fusion outcome. Sixteen patients (19 levels) treated with decompression and intertransverse process fusion using pedicle screw fixation without facet arthrodesis were entered into a cross sectional study in which the fusion status of the intertransverse fusion masses and facet joints at each fusion level were evaluated and combined at an average duration of followup of 35 months (range, 22-61 months). Union rate of the intertransverse process fusion (58%, 22 of 38) was lower than the spontaneous fusion rate of the facet joint (68%, 26 of 38). However, the combination of the two fusion statuses at each fusion level generated 89% of the overall fusion rate (17 of 19 levels). With surgery, all patients had a good or excellent clinical outcome, but the outcome had no relation to the overall fusion status. The results suggest that the fusion status of the facet joint should be considered in determining overall fusion status after combined decompression with instrumented intertransverse process fusion.

Adult↗

PubMed1999

Contrast enhancement of small hepatocellular carcinoma: usefulness of three successive early image acquisitions during multiphase dynamic MR imaging.

OBJECTIVE: The purpose of this study was to document the usefulness of early triphasic image acquisition during gadolinium-enhanced multiphase dynamic MR imaging for the detection of contrast enhancement in small hepatocellular carcinoma. SUBJECTS AND METHODS: Dynamic MR imaging was performed in 332 patients at 1.5 T using a T1-weighted fast low-angle shot sequence (TR range/TE, 113-130/4.1; flip angle, 80 degrees). With the start of bolus injection of gadolinium dimeglumine (0.1 mmol/kg) into the antecubital vein, three sets of contrast-enhanced images of the entire liver were obtained serially at 10, 35, and 60 sec. Contrast enhancement of the tumor detected on each phase was evaluated in conjunction with the unenhanced T1-weighted images for 52 patients with small hepatocellular carcinomas up to 2 cm in diameter (n = 79). RESULTS: The first phase images depicted a larger number (n = 57) of contrast enhancement of small hepatocellular carcinoma tumors than the second (n = 44) or third phase images (n = 14). Twenty-six lesions were enhanced only during the first phase, and nine, during the second phase. The detection rate of contrast enhancement in the combination of first and second phases was the same as the overall detection rate for all three phases (70/79, 89%) and significantly higher than those of each phase. CONCLUSION: Early multiple image acquisition is helpful for the assessment of small hepatocellular carcinoma and is enabled by the high detection rate of contrast enhancement regardless of individual variations in the timing of enhancement.

Carcinoma, Hepatocellular↗