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K H Lee

Publications and source records attributed to K H Lee.

At least 55 records · Page 3Linked to original sources
PubMed2004

Real-time compound ultrasonography: pictorial review of technology and the preliminary experience in clinical application of the abdomen.

The purposes of this essay are to illustrate the technology overview and theoretical benefits of real-time compound ultrasonography (US) and to present our preliminary clinical experience in the evaluation of normal and diseased abdomens. The application of compounding principles to real-time US and its recent reintroduction into mainstream commercial systems have offered new opportunities for its clinical application to the routine examination of the abdomen. In our early preliminary experience, this technique effectively suppressed many of the US artifacts, better depicted the margin or boundary of the lesion, and increased contrast resolution or lesion conspicuity. Therefore, we believe that real-time compound US is a promising technique that may enhance the diagnostic confidence of the examination in the evaluation of normal and diseased abdomens.

Abdomen↗
PubMed2004

Tissue specific expression and sequence analysis of a stress responsive gene Bre in adult golden hamster (Mesocricetus auratus).

Bre (brain and reproductive organ-expressed) is a new and putative stress-modulating gene of yet unknown function. BRE has previously been shown to interact with type 1 tumor necrosis factor receptor (TNFR1) and modulate the action of TNF. Apart from the brain and reproductive organs, Bre and BRE are highly expressed in steroid producing tissues such as the adrenal gland. Here we report for the first time the cloning of the Bre gene from golden hamster, a model organism extremely valuable for reproduction and steroid research, and examination of its tissue specific expression. Sequence analysis demonstrated that the peptide sequence of BRE in hamster shares approximately 99% homology with those of human, monkey and mouse. The hamster Bre gene transcribed an approximately 1.8-kb mRNA which translated a 44-kDa protein. Bre was strongly expressed in neurons and luminal epithelia of urogenital, digestive and respiratory organs. Bre was also detected in lymphoid tissues and endocrine glands. Immunohistochemistry demonstrated a similar protein expression pattern. Exceptions to this included the adrenal gland, where a high level of Bre was accompanied by weak immunoreactivity; as well as the oocytes and islets of Langerhans, where BRE protein but not the mRNA was localized. These data indicated that Bre gene products were expressed in a wide variety of tissues other than the brain and reproductive organs, as was originally described. Based on our findings, we propose that Bre is a housekeeping gene in tissues that are constantly subjected to environmental hazards such as luminal epithelia. Our results further support the proposed role for BRE in endocrine and immune functions.

Animals↗
PubMed2004

Antioxidative effects of 7-hydroxy-3-methoxy-cadalene extracted from Zelkova serrata on 4-(methylinitros amino)-1-(3-pyridyl)-1-butanone-induced oxidative stress in A/J mice.

Effects of 7-hydroxy-3-methoxy-cadalene (cadalene) extracted from Zelkova serrata on 4-(methylinitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced oxidative stress were examined using A/J mice. NNK (65 microg/ml water) was orally administered to 20 mice for 7 weeks, followed by free feeding of a commercial diet, not containing cadalene, for 2 weeks. The control group was maintained without NNK and cadalene administration, and treatment groups with NNK and cadalene (6.25, 25, 100 mg/kg feed) feeding for 25 weeks. The glutathione concentration of cadalene-treated (65 microg/ml water) group was significantly higher than that of the group treated only with NNK (p < 0.05). The results of our study strongly indicate that cadalene exerts antioxidative effect on NNK-induced lung tumorigenesis in A/J mice.

Administration, Oral↗
PubMed2004

The clinicopathological significance of inferior mesenteric lymph node metastasis in colorectal cancer.

AIMS: There are few studies reporting survival or recurrence patterns in colorectal cancer patients with inferior mesenteric lymph node metastasis (IMLN+). The present study evaluated the prognostic significance of patients being IMLN+ or IMLN- in colorectal cancer. METHODS: Survival, recurrence pattern and treatment protocols were compared between 63 IMLN+ patients and 108 IMLN- patients with stage III and IV rectal and sigmoid cancer undergoing curative surgery. Lymph node sampling was routinely performed prior to inferior mesenteric artery ligation and excision flush with aorta. Limited principal node dissection including IMLN was performed in cases of identified node metastasis. RESULTS: The 5-year disease-free survival rates were 50% in IMLN- and 31% in IMLN+ patients (P=0.004). The 5-year disease-free survival rate was greater in the N1 group than the N2 group (P=0.038). Cox regression analysis showed IMLN+, lymphovascular tumour invasion, T4, M1, and pre-operative serum CEA level over 6 ng/ml were independently associated with unfavorable disease-free survival. The prognostic significance of M category was greater when the IMLN+ was included in the M1 as opposed to the N category. In patients undergoing absolute curative surgery, post-operative recurrence rates were 34% for IMLN- and 57% for IMLN+ patients (P=0.009; OR, 2.611; 95% CI, 1.313-5.194). For IMLN+ patients, post-operative adjuvant treatment independently correlated with disease-free survival (P=0.029). CONCLUSIONS: IMLN+ is an independent survival factor enhancing the prognostic significance of the M category in the AJCC staging. Curative radical surgery and post-operative chemoradiotherapy appears to be warranted for IMLN+ colorectal cancer patients as it resulted in 5-year disease-free survival rates of up to 31% compared to 50% in IMLN- patients.

Adult↗
PubMed2004

Evidence for an axonal localization of the type 2 corticotropin-releasing factor receptor during postnatal development of the mouse cerebellum.

Previous studies have described the embryonic and postnatal development of CRF, as well as the type 1 CRF receptor in the mouse cerebellum. The present immunohistochemical study localizes the cellular distribution of the type 2 CRF receptor (CRF-R2) during postnatal development of the mouse cerebellum. Western blot analysis indicates that the antibody used in this analysis recognizes both a full-length and a truncated isoform of the type 2 receptor. We propose that each isoform has a unique cellular distribution. In the present study, the postnatal (P) development (P0-P14) and cellular localization of CRF-R2 in different cell types was analyzed using PAP and double-label fluorescent immunohistochemistry; cell-specific antibodies were used to identify cells expressing CRF-R2 at different stages of postnatal development. At P0, CRF-R2 immunoreactivity was localized within the somata of Purkinje cells and migrating GABAergic interneurons. CRF-R2 was first observed in the initial axonal segments of some Purkinje cells at P5, and was evident in many Purkinje cell axon hillocks at P8. Punctate immunoreactivity is present in the molecular layer by P5 and is interpreted to be immunolabeled parallel fibers. Between P8 and P14, CRF-R2 immunostaining is present in the initial axonal segments of Golgi cells, within the internal granule cell layer. Finally, CRF-R2 is present in both radial glia in the molecular layer as well as in astrocytes in the white matter and internal granule cell layer from P5 to P14. The present results suggest that CRF-R2, both the truncated and the full-length isoforms, are present in the developing cerebellum, each with a unique cellular distribution. The immunohistochemical evidence indicates that the truncated isoform of the type 2 CRF receptor is in the axons of several different types of cerebellar cortical neurons, and suggests that CRF could play a role in cerebellar development by modulating the release of transmitters from excitatory and/or inhibitory interneurons, which in turn could directly alter the maturation of cerebellar circuits. In contrast, the binding of a ligand to the full-length isoform of CRF-R2 or to CRF-R1, both in a postsynaptic location, may have a more direct effect on regulating the responsiveness of these cells to growth factors or neurotransmitters released from afferent axons by regulating permeability of ion channels or altering second messenger systems.

Animals↗
PubMed2004

The Character-line Bisection Task: a new test for hemispatial neglect.

A failure to report or respond to stimuli presented in a portion of space is termed hemispatial neglect. Line bisection and line cancellation are two of the tests used most commonly to assess for neglect. Perhaps, because neglect can be induced by a variety of deficits, neither of these tests used alone is as sensitive as both used together. Hence, the primary purpose of this study was to assess the sensitivity, reliability and validity of a new test called the Character-line Bisection Task (CLBT) that combines features of both the bisection and cancellation tests. Since local attention and language are primarily mediated by and activate the left hemisphere, our second goal was to learn if the CLBT and especially the letter version induce a greater rightward bias than the solid-line bisection task. Eighty patients with acute right hemisphere stroke and 81 controls performed the CLBT that consists of two subtests, the Letter-line and Star-line Bisection tasks. All subjects also completed four conventional tests for neglect (Standard solid-line bisection, line cancellation, Star Cancellation, and figure copying). In the bisection tasks both patients and controls bisected to the right with the CLBT than with the solid-line bisection task, suggesting the CLBT induces asymmetrical hemispheric activation. This enhanced rightward deviation with the CLBT was the same for the Letter-line and Star-line Bisection tasks. In regard to sensitivity, we defined the presence of neglect syndrome based on a total score derived from performance of controls on all six tests. This total score detected 55 (68.8%) patients with neglect. Within this group, the Letter-line and Star-line tasks diagnosed neglect in 50 and 48 patients, respectively, resulting in the highest sensitivities (90.9, 87.3%) of the six tests. Thus, the CLBTs demonstrated higher sensitivities than the other commonly used neglect tests and these new tests can be useful for the detection and quantification of unilateral neglect.

Adult↗
PubMed2004

Successful listing of patients for liver transplant was related to participation of referring doctor in the transplant program.

INTRODUCTION: Experience with liver transplantation is limited in many parts of Asia. Therefore, patients from nontransplant centers may not be referred in a timely fashion for transplants. Our aim was to evaluate the pattern of referral for liver transplantation and their outcomes in Singapore. METHODS: Consecutive patients referred from 1990 to 2001 were reviewed. Patients from any hospital in Singapore (or the region) could be referred to the program. They were discussed at the weekly meetings. Appropriate patients were placed on the waiting list. "Pending" indicated that the disease was early or there were unsettled medical or social issues. Unsuitable patients were "rejected" for transplant. RESULTS: There were 385 patients referred over a 12-year period. Hepatitis B cirrhosis and hepatocellular carcinoma (HCC) were the most common indications among adults, whereas biliary atresia was the most common for children. Pediatric patients were more likely than adult patients to be listed for transplant (53/76 vs 106/309, P < .001). Patients referred by regular attendees of the program were more likely to be accepted than nonattendees (38% vs 25%, P = .04). "Disease too early", "advanced HCC", and "refusal by family members" were the most common reasons for rejection. CONCLUSION: Members of the Liver Transplant Program were more likely to refer suitable patients for transplant at the appropriate time. Better interaction between gastroenterologists inside and outside the transplant program would help to improve the timing of referrals for liver transplantation, and hence, patient survival.

Adult↗
PubMed2004

The MELD score may help to determine optimum time for liver transplantation.

BACKGROUND: The model for end-stage liver disease (MELD) score is a good predictor of mortality on the waiting list and short-term survival post liver transplantation. AIM: Our aim was to determine if there is a pretransplant MELD score beyond which liver transplantation is prohibitive. PATIENTS AND METHODS: Forty-six adult patients underwent primary liver transplantation from January 1996 to December 2002. Patients followed to the most recent visit or death underwent survival analysis using Cox regression and Kaplan Meier methods. RESULTS: There was a significant correlation between the pretransplant MELD score and survival at 6 months posttransplant (P=.037 95% CI: 1.004-1.13). Patients with pretransplant MELD score greater than or equal to 32 showed significantly greater mortality compared with those less than 32 (HR 9.18, 95%CI=1.16-72.44). CONCLUSION: Pretransplant MELD may help to determine the optimum time for liver transplantation.

Adult↗
PubMed2004

Social cognition, brain networks and schizophrenia.

BACKGROUND: A better understanding of the neural basis of social cognition including mindreading (or theory of mind) and empathy might help to explain some deficits in social functioning in people with schizophrenia. Our aim was to review neuroimaging and neuropsychological studies on social cognition, as they may shed light on the neural mechanisms of social cognition and its dysfunction in patients with schizophrenia. METHOD: A selective literature review was undertaken. RESULTS: Neuroimaging and neuropsychological studies suggest convergence upon specific networks for mindreading and empathy (the temporal cortex, amygdala and the prefrontal cortex). The frontal lobe is likely to play a central role in enabling social cognition, but mindreading and empathic abilities may require relatively different weighting of subcomponents within the same frontal-temporal social cognition network. CONCLUSIONS: Disturbances in social cognition may represent an abnormal interaction between frontal lobe and its functionally connected cortical and subcortical areas. Future studies should seek to explore the heterogeneity of social dysfunction within schizophrenia.

Brain Mapping↗
PubMed2004

Influence of maternal serum levels of vitamins C and E during the second trimester on birth weight and length.

OBJECTIVE: It has been known that maternal oxidative stress during pregnancy plays an important role in fetal growth. However, the association between antioxidant vitamin levels and birth outcomes is not conclusive. We investigated the relationship between maternal serum levels of vitamins C and E during the second trimester and birth weight and length. DESIGN: Prospective cohort study. SETTING: Outpatient-clinic of obstetrics, Ewha Womans University Hospital, South Korea. SUBJECTS AND METHODS: The study subjects were 239 healthy, pregnant women who visited an obstetric clinic for antenatal care, and their singleton live births, in Seoul, Korea, between August 2001 and March 2003. We measured the levels of vitamins C and E in maternal serum during the period 24-28 gestational weeks. Each woman was interviewed for dietary intake by trained interviewers during the second trimester. RESULTS: The serum concentration of maternal vitamin C during the second trimester was significantly associated with birth weight and length in the group of full-term deliveries. An increase of 1 microg/ml in the serum vitamin C level increased the birth weight by 27.2 g and the birth length by 0.17 cm. When we considered the levels of vitamins C and E together in the relationship with birth weight and length, we found that the heaviest birth weight and the longest birth length belonged to the group of upper vitamin C/upper vitamin E. However, dietary intake estimated by 24-h recall method was not a predictor of the levels of serum vitamins C and E. CONCLUSION: We found that maternal serum vitamin C levels during the second trimester were positively correlated with birth weight and length in full-term babies. We also found that birth weight and length were highest when the levels of both vitamins C and E were high. Our results indicate the importance of antioxidant nutrient balance for pregnant women who are exposed to various oxidants through food, drinking water, or inhaled air.

Antioxidants↗
PubMed2004

A multicenter trial of the efficacy and safety of 0.03% tacrolimus ointment for atopic dermatitis in Korea.

BACKGROUND: Atopic dermatitis is a chronically relapsing, common inflammatory skin disease, which significantly affects quality of life negatively in many respects. Topical steroids are the mainstay of atopic dermatitis treatment but they carry the risk of local side effects. A topical formulation of tacrolimus, a macrolide calcineurin inhibitor, has recently been developed. OBJECTIVE: To evaluate the efficacy and safety of 0.03% tacrolimus ointment for the treatment of moderate to severe atopic dermatitis in Korea. METHODS: An open, non-comparative, multi-center study with 4 weeks' follow-up was performed. A total of 180 patients (aged 2-57 years old) were enrolled. Tacrolimus ointment (0.03%) was applied to all involved areas twice daily. Efficacy was evaluated by an investigator's global assessment, the eczema area and severity index score, and by the patient's assessment of pruritus and clinical response at baseline, and after weeks 1, 2 and 4. Dermatology life quality index (DLQI), children's DLQI (CDLQI) and toddler's DLQI were assessed at baseline and at week 4. The safety assessment included monitoring all adverse events and clinical laboratory values. RESULTS: All efficacy parameters were improved. The mean EASI (eczema area and severity index) score was 19.7 at baseline and reduced to 8.0 at the end of the study. Moderate improvement was observed by the investigator's global assessment after 4 weeks' treatment. A marked decrease of pruritus was observed, and mild or moderate improvement was observed by patients' global assessments after the treatment period. Significant benefits in terms of quality of life in adults and children with atopic dermatitis were obtained. The most common adverse events associated with tacrolimus treatment were transient skin burning sensation (45.3%) and pruritus (41.6%) at the site of application. CONCLUSION: 0.03% tacrolimus ointment should be considered effective and safe in both Korean children and adults with moderate to severe atopic dermatitis.

Administration, Cutaneous↗
PubMed2004

The statistical mechanics of complex signaling networks: nerve growth factor signaling.

The inherent complexity of cellular signaling networks and their importance to a wide range of cellular functions necessitates the development of modeling methods that can be applied toward making predictions and highlighting the appropriate experiments to test our understanding of how these systems are designed and function. We use methods of statistical mechanics to extract useful predictions for complex cellular signaling networks. A key difficulty with signaling models is that, while significant effort is being made to experimentally measure the rate constants for individual steps in these networks, many of the parameters required to describe their behavior remain unknown or at best represent estimates. To establish the usefulness of our approach, we have applied our methods toward modeling the nerve growth factor (NGF)-induced differentiation of neuronal cells. In particular, we study the actions of NGF and mitogenic epidermal growth factor (EGF) in rat pheochromocytoma (PC12) cells. Through a network of intermediate signaling proteins, each of these growth factors stimulates extracellular regulated kinase (Erk) phosphorylation with distinct dynamical profiles. Using our modeling approach, we are able to predict the influence of specific signaling modules in determining the integrated cellular response to the two growth factors. Our methods also raise some interesting insights into the design and possible evolution of cellular systems, highlighting an inherent property of these systems that we call 'sloppiness.'

Animals↗
PubMed2004

Performance of large-size superconducting coil in 0.21T MRI system.

A high-temperature superconductor (HTS) was used on magnetic resonance imaging (MRI) receiver coils to improve image quality because of its intrinsic low electrical resistivity. Typical HTS coils are surface coils made of HTS thin-film wafers. Their applications are severely limited by the field of view (FOV) of the surface coil configuration, and the improvement in image quality by HTS coil is also reduced as the ratio of sample noise to coil noise increases. Therefore, previous HTS coils are usually used to image small in vitro samples, small animals, or peripheral human anatomies. We used large-size HTS coils (2.5-, 3.5-, and 5.5-in mean diameter) to enhance the FOV and we evaluated their performance through phantom and human MR images. Comparisons were made among HTS surface coils, copper surface coils, and cool copper surface coils in terms of the signal-to-noise ratio (SNR) and sensitivity profile of the images. A theoretical model prediction was also used to compare against the experimental result. We then selected several human body parts, including the wrist, feet, and head, to illustrate the advantage of HTS coil over copper coil when used in human imaging. The results show an SNR gain of 200% for 5.5-in HTS coil versus same size copper coils, while for 2.5- and 3.5-in coils it is 250%. We also address the various factors that affect the performance of large size HTS coils, including the coil-to-sample spacing due to cryogenic probe and the coil-loading effect.

Electric Conductivity↗
PubMed2004

Combined use of autologous transfusion techniques to avoid allogeneic transfusion in spinal fusion surgery with instrumentation.

This study conducted a retrospective review of the medical records of 321 patients to delineate the efficacy of the combined use of autologous transfusion (AT) techniques. Transfusion profiles between an AT and homologous transfusion (HT) group were compared. A much lower proportion of patients were exposed to allogeneic blood in the AT group (13%) than in the HT group (98%, p<0.001). In the AT group, a significantly smaller proportion of patients were exposed to allogeneic blood in patients transfused with three or four AT techniques (8%) than those with one or two techniques (29%, p<0.05). A febrile reaction (11% of patients) after a reinfusion of post-operatively shed blood was the only side effect associated with an AT. In conclusion, an AT is effective for preventing the exposure of allogeneic blood in spinal fusion surgery. The combined use of multiple AT techniques may further improve its efficacy.

Adult↗
PubMed2004

Dynamic gadolinium-enhanced magnetic resonance urography for assessing drainage in dilated pelvicalyceal systems with moderate renal function: preliminary results and comparison with diuresis renography.

OBJECTIVE: To evaluate the use of dynamic gadolinium diethylenetriaminepenta-acetic acid (DTPA)-enhanced magnetic resonance urography (Gd-MRU) for assessing kidneys with markedly dilated pelvicalyceal systems and impaired function. PATIENTS AND METHODS: Eight children (mean age 30 months, sd 25) were assessed, diagnosed as having gross unilateral hydronephrosis with a mean (sd) anteroposterior renal pelvic diameter of 36 (7) mm and reduced (30-40%) renal function. Dynamic Gd-MRU was performed after the patients were pre-loaded with intravenous fluid and diuretics, and comprised a dynamic T1-weighted sequence after Gd-DTPA (0.1 mmol/kg body weight) was administered, with a time-intensity curve of each kidney produced. Drainage was diagnosed by a clearly declining time-intensity curve and direct visualization of contrast medium within the ureter in several frames. High-grade or complete obstruction was diagnosed when drainage of contrast medium could not be detected. Gd-MRU results were compared with diuresis radionuclide (mercapto-acetyltriglycine, MAG3) renography within the same week. Unobstructive units detected by Gd-MRU were treated conservatively with a close follow-up by ultrasonography and radionuclide studies. RESULTS: Diuresis MAG3 renography showed drainage in three dilated units and poor washout in five; in contrast, Gd-MRU showed drainage in seven dilated systems (three showed poor washout by MAG3), and obstruction in the remaining case. The unobstructed units detected by MRU under conservative treatment thus showed no further deterioration of renal function or progressive hydronephrosis in the subsequent follow-up (mean 18 months, range 15-23). CONCLUSION: These preliminary results suggest that dynamic Gd-MRU is a useful noninvasive imaging method in distinguishing obstructive from unobstructive dilated systems, particularly in patients with hydronephrosis and reduced renal function.

Child↗
PubMed2003

Embryos sired by males without accessory sex glands induce failure of uterine support: a study of VEGF, MMP and TGF expression in the golden hamster.

To account for reproductive failure induced by surgical deletion of paternal accessory sex glands in the golden hamster in vivo, we studied expression of vegf, FLT-1 (VEGF-R1), FLK-1 (VEGF-R2), MMP and TGF-beta in endometrium of the dam and sired embryos during 5-7 days post coitum by immunohistochemistry, in situ hybridisation, semiquantitative RT-PCR and enzyme-linked immunosorbent assay. Spatiotemporal pattern of vegf expression in the control animals was similar to that reported for intact animals by our group. Removal of paternal ampullary glands did not disturb the normal expression pattern. Removal of ventral prostate glands alone or all accessory sex glands was associated with reduction of vegf transcripts and protein levels in both the embryo and endometrium. FLT-1, FLK-1 and MMP-2 were also reduced. MMP-1 was not changed whereas TGF-beta1 expression was enhanced. There was no expression in endometrium in between implantation sites. Thus the implanted embryos had a trophic effect on growth factor production by the endometrium, and the levels of expression were determined by viability and structural integrity of the conceptus. Based on these findings we concluded that incompetent embryos sired by males without the ventral prostate gland or all accessory sex glands reduced the potential of the uterus to support pregnancy. A negative cycle of events was thus set up and eventually led to premature termination of pregnancies.

Animals↗
PubMed2003

Hyperventilation-induced limb shaking TIA in Moyamoya disease.

The authors present a case of hyperventilation-induced left upper limb shaking from an underlying Moyamoya disease. Video EEG monitoring and SPECT study were performed. Leptomeningeal collateral circulation was investigated by conventional angiography and by SPECT study with acetazolamide. Limb shaking in Moyamoya disease may result from a transient hypoperfusion of the contralateral frontoparietal cortex rather than basal ganglia.

Acetazolamide↗