Biomedical subjects

J H Lee

Publications and source records attributed to J H Lee.

At least 19 recordsLinked to original sources

PubMed2006

Isolation and phylogenetic analysis of H1N1 swine influenza virus isolated in Korea.

A swine influenza H1N1 virus was isolated from a pig during a severe outbreak of respiratory disease in Korea. All genes of the H1N1 isolate, including hemagglutinin (HA), neuraminidase (NA), matrix (M), nucleoprotein (NP), non-structural (NS), PA, PB1 and PB2, were of swine origin. Also, all these genes showed a close phylogenic relationship with those of H1N1 viruses previously isolated from pigs in the United States. These results suggest that North American swine influenza virus has actually been transmitted to pigs in Korea.

Animals↗

PubMed2006

Complete ophthalmoplegia after herpes zoster.

Motor loss caused by herpes zoster is infrequent, and only a few studies have focused on ocular motor paralysis in ophthalmic herpes zoster. We report a case of complete ophthalmoplegia resulting from ophthalmic herpes zoster. A 69-year-old man presented with complete left-side ptosis with total ophthalmoplegia 7 days after the onset of left ophthalmic herpes zoster. The patient was treated with aciclovir and prednisolone. Five months later, the ptosis had resolved and the extraocular motility had almost returned to normal.

Acyclovir↗

PubMed2006

Effects of chronic angiotensin II receptor antagonist and angiotensin-converting enzyme inhibitor treatments on neurohormonal levels and haemodynamics during cardiopulmonary bypass.

BACKGROUND: Chronic treatment with renin-angiotensin system (RAS) antagonists frequently causes deleterious hypotension during anaesthesia. We compared the effects of angiotensin II receptor antagonists (ARA) and angiotensin-converting enzyme inhibitors (ACEI) on neurohormonal levels and haemodynamics during cardiopulmonary bypass (CPB). METHODS: Forty-four patients undergoing mitral valvular surgery who were treated with either ARA (ARA group, n=14) or ACEI (ACEI group, n=15) over 12 weeks or who were not treated with any RAS antagonist (control group, n=15) were enrolled. The plasma levels of epinephrine, norepinephrine, arginine vasopressin (AVP) and angiotensin II, and haemodynamic variables were measured before (T1) and 15 min after (T2) the start of CPB, before aortic unclamping (T3) and at skin closure (T4). Mean arterial pressure (MAP) was maintained above 60 mm Hg with phenylephrine administration during CPB. RESULTS: The plasma epinephrine, norepinephrine, AVP and angiotensin II levels increased during CPB in all groups. Compared with the control group, the AVP level was lower at T1 in the ARA group and at T2 in the ARA and ACEI groups. The angiotensin II level was higher at T1, T2 and T3 in ARA group compared with ACEI and control groups. There were no significant differences in the epinephrine and norepinephrine levels among the three groups. The amount of administered phenylephrine during CPB was greater and MAP was lower in the ARA group compared with the ACEI and control groups. CONCLUSIONS: Chronic ARA treatment resulted in more profound hypotension than ACEI treatment during CPB, and this may be associated with the blockade of angiotensin II receptors by ARA.

Adult↗

PubMed2006

Simultaneous measurement of bending and temperature based on a single sampled chirped fiber Bragg grating embedded on a flexible cantilever beam.

We propose and experimentally demonstrate a simple and practical scheme for simultaneous measurement of bending and temperature based on a single sampled chirped fiber Bragg grating with multiple resonant peaks, which is embedded on a flexible cantilever beam. The wavelength spacing of the grating can be changed by adjusting the bending curvature change, since the compressive strain gradient induced by the bending of the cantilever beam changes the chirp ratio of the fiber grating. However, the wavelength spacing of the fiber grating is not changed by the temperature variation; the multiple resonant wavelengths are only shifted into the longer wavelength because of the positive thermal-expansion and thermo-optic coefficients of the fiber grating. Consequently, the proposed scheme allows for discrimination between two effects of bending and temperature.

Journal Article↗

PubMed2006

Subdural hematoma in spontaneous CSF hypovolemia.

Of 67 consecutive patients with spontaneous CSF hypovolemia (SCH), 11 (16.4%) had subdural hematoma (SDH). Patients with SDH were older (p = 0.005), more likely to be male (p = 0.035), and displayed longer time to diagnosis of SCH (p = 0.019) than those without SDH. All patients with SDH showed the findings of pseudo-subarachnoid hemorrhage on CT and responded favorably to epidural blood patches and neurosurgical drainage.

Adult↗

PubMed2006

Acquisition of MR perfusion images and contrast-enhanced MR angiography in acute ischaemic stroke patients: which procedure should be done first?

Multimodal MRI for acute ischaemic stroke usually includes perfusion imaging (PI) and contrast-enhanced neck MR angiography (CE-MRA), as well as diffusion-weighted imaging and T2* weighted imaging. Because both PI and CE-MRA require the infusion of contrast medium, the likelihood exists that one study may conflict with the other due to the accumulation of previously injected contrast medium. The purpose of this study is to determine the appropriate order of PI and CE-MRA in this multimodal MRI protocol for evaluation of acute ischaemic stroke. We studied 35 patients with acute ischaemic stroke in the unilateral middle cerebral artery territory. 17 patients underwent CE-MRA following PI (group A) and 18 patients underwent PI following CE-MRA (group B). For qualitative analysis of the CE-MRA and colour-coded maps of the PI, two independent observers graded the image quality. Interobserver agreement was assessed using kappa statistics, and we assessed the statistical differences of imaging quality between groups A and B using the Mann-Whitney U-test). For the quantitative analysis of PI, two parameters--the maximum change in the transverse relaxation rate (DeltaR2(max)) and the relative signal drop (DeltaS/S(0))--were calculated from the time-signal intensity curve of an unaffected middle cerebral artery territory, and we compared the differences in the parameters of group A and B (t-test). Interobserver agreements for CE-MRA and PI were good. In the qualitative analysis of CE-MRA and PI, no significant difference was observed between groups A and B. In the quantitative analysis of PI, there were no relevant differences in DeltaR2(max) and DeltaS/S(0) between the two groups. In simultaneous CE-MRA and PI, there was no deterioration of diagnostic imaging quality with regard to the order of the two post-contrast sequences. They can be performed according to the preference of each institution.

Acute Disease↗

PubMed2006

TENOR risk score predicts healthcare in adults with severe or difficult-to-treat asthma.

The aim of the present study was to predict which patients with severe or difficult-to-treat asthma are at highest risk for healthcare utilisation can be predicted so as to optimise clinical management. Data were derived from 2,821 adults with asthma enrolled in The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study. Multiple potential predictors were assessed at baseline using a systematic algorithm employing stepwise logistic regression. Outcomes were asthma-related hospitalisations or emergency department (ED) visits within 6 months following baseline. Overall, 239 subjects (8.5%) reported hospitalisation or ED visits at follow-up. Predictors retained after multivariate analysis were as follows: younger age; female sex; non-white race; body mass index > or =35 kg x m(-2); post-bronchodilator per cent predicted forced vital capacity <70%; history of pneumonia; diabetes; cataracts; intubation for asthma; and three or more steroid bursts in the prior 3 months. A final risk score derived from the logistic regression model ranged from 0-18 and was highly predictive (c-index: 0.78) of hospitalisation or ED visits. This tool was re-tested in a prospective validation using outcomes at 12- to 18-months follow-up among the same cohort (c-index: 0.77). The risk score derived is a clinically useful tool for assessing the likelihood of asthma-related hospitalisation or emergency department visits in adults with severe and difficult-to-treat asthma.

Adolescent↗

PubMed2006

Early onset severe and late-onset mild Charcot-Marie-Tooth disease with mitofusin 2 (MFN2) mutations.

Mutations in the mitofusin 2 (MFN2) gene, which encodes a mitochondrial GTPase mitofusin protein, have recently been reported to cause both Charcot-Marie-Tooth 2A (CMT2A) and hereditary motor and sensory neuropathy VI (HMSN VI). It is well known that HMSN VI is an axonal CMT neuropathy with optic atrophy. However, the differences between CMT2A and HMSN VI with MFN2 mutations remained to be clarified. Therefore, we studied the phenotypic characteristics of CMT patients with MFN2 mutations. Mutations in MFN2 were screened in 62 unrelated axonal CMT neuropathy families. We calculated CMT neuropathy scores (CMTNSs) and functional disability scales (FDSs) to quantify disease severity. Twenty-one patients with the MFN2 mutations were studied by brain MRI. Ten pathogenic mutations were identified in 26 patients from 15 families (24.2%). Six of these mutations had not been reported, and de novo mutations were observed in five families (33.3%). The electrophysiological patterns of affected individuals with the MFN2 mutations were typical of axonal CMT; however, the clinical and electrophysiological characteristics were markedly different in early (<10 years) and late disease-onset (> or =10 years) groups. All patients with an early onset had severe CMTNS (> or =21) and FDS (6 or 7), whereas most patients with late onset had mild CMTNS (< or =10) and FDS (< or =3). We identified two HMSN VI families with the R364W mutation in the early onset group; however, two other families with the same mutation did not have optic atrophy. In addition, two early onset families with R94W mutations, previously reported for HMSN VI, did not have visual impairment. Interestingly, eight patients had periventricular and subcortical hyperintense lesions by brain MRI. In the late-onset group, three patients had sensorineural hearing loss and two had bilateral extensor plantar responses. We found that MFN2 mutations are the major cause of axonal CMT neuropathy, and that they are associated with variable CNS involvements. Phenotypes were significantly different in the early and late disease-onset groups. Our findings suggest that HMSN VI might be a variant of the early onset severe CMT2A phenotype.

Adolescent↗

PubMed2006

Non-surgical management of microperforation induced by EMR of the stomach.

BACKGROUND: Perforation and bleeding are major complications associated with gastric endoscopic mucosal resection. Evident perforation during endoscopic mucosal resection can be managed by endoscopic clipping. However, management of microperforation is not well established. PATIENT AND METHOD: From January 2002 to June 2004, 109 early gastric cancers and 300 adenomas were treated with endoscopic mucosal resection. Iatrogenic perforations occurred in 4.16% (n=17) patients. Following exclusion of four evident perforations, microperforation was observed in 3.18% (n=13) patients. The clinical features of microperforation in patients were retrospectively reviewed. RESULTS: In a total of 13 microperforation cases, 2 patients were managed surgically. The remaining patients successfully recovered without surgical management. In the case of 11 patients without surgery, 7 experienced abdominal pain, which required analgesics, 2 patients experienced mild discomfort and 2 patients experienced no symptoms. A body temperature above 37.5 degrees C was observed in 9.1% (n=1) patients and leucocytosis above 9000 microL-1 was in 72.7% (n=8) patients. The mean duration of nasogastric tube drainage was 2.36+/-1.03 days, of fasting 4.18+/-1.17 days, of intravenous antibiotics 5.55+/-1.44 days and of hospitalisation 7.45+/-1.04 days. CONCLUSION: Microperforation induced by gastric endoscopic mucosal resection can be managed successfully using a non-surgical approach including fasting, nasogastric tube drainage and intravenous antibiotics.

Abdominal Pain↗

PubMed2006

Effect of orbital rotation and mixing on the optical properties of orthorhombic RMnO3 (R=La, Pr, Nd, Gd, and Tb).

We investigated the ab-plane absorption spectra of RMnO3 (R=La, Pr, Nd, Gd, and Tb) thin films. As the ionic radius of the R ion decreases, we observed a drastic suppression of the 2 eV peak, i.e., the intersite optical transition between spin- and orbital-aligned states across the Mott gap. We found that, in addition to orbital rotation, orbital mixing in the orbital-ordered state should play an important role in the suppression of 2 eV peak. We also found that the spectral weight of 2 eV peak is proportional to the A-type antiferromagnetic ordering temperature, which suggests that the magnetic interaction should be sensitively coupled to the orbital degree of freedom.

Journal Article↗

PubMed2006

Short-term effect of intracameral triamcinolone acetonide on corneal endothelium using the rabbit model.

PURPOSE: To investigate the effect of intracameral injection of triamcinolone acetonide on the corneal endothelium in rabbit eyes. METHODS: Triamcinolone acetonide (40 mg/ml, 0.2 cm3) after filtering and resuspension in balanced salt solution (BSS) was injected intracamerally for 3 min into 10 rabbit eyes and irrigated with 5 cm(3) of BSS. Triamcinolone without resuspension and BSS were injected, respectively, into five rabbit eyes. Endothelial toxicity was evaluated and compared by measurements of endothelial cell counts and central corneal thickness. The endothelial viability was determined using vital staining with alizarin red and trypan blue at 2 h after injection. The scanning electron microscopy (SEM) was performed in one cornea from each group. RESULTS: Endothelial cell counts and central corneal thickness following intracameral injection of triamcinolone acetonide did not significantly change when compared to controls. The mean percentage of viable endothelial cells was 99.50, 99.52, and 99.49% in the resuspended triamcinolone group, triamcinolone without resuspension group, and BSS group, respectively (P=0.46, Kruskall-Wallis test). But SEM showed reduced microvilli of endothelial surface in an eye of the triamcinolone without resuspension group. CONCLUSIONS: The intracameral injection of triamcinolone acetonide did not induce a significant visible change of endothelium in rabbit eyes. However, ultrastructural villi changes observed suggest a possibility of microstructural damages in endothelium with triamcinolone acetonide injection when used without filtering and resuspension.

Animals↗

PubMed2006

Phase II study of docetaxel and irinotecan combination chemotherapy in metastatic gastric carcinoma.

The current treatment for metastatic gastric cancer (MGC) consists of cisplatin and/or fluorouracil (5-FU) based combination chemotherapy, but cisplatin-based regimens are associated with considerable toxicity. We evaluated the efficacy and safety of a noncisplatin-, non-5-FU-containing regimen, docetaxel/irinotecan in MGC. Chemo-naive patients with MGC received docetaxel (30 mg m(-2)) and irinotecan (70 mg m(-2)) on days 1 and 8 every 3 weeks. The 48 eligible patients (median age 56 years) received a median of four cycles of docetaxel/irinotecan (range 1-18). Of the 46 patients in whom efficacy could be evaluated, 21 showed a partial response (response rate=45.7%; 95% confidence interval (CI) 31.3-60.1%). At a median follow-up of 15.0 months, the median time to progression was 4.5 months (95% CI 3.8-5.2 months) and overall survival was 8.2 months (95% CI, 5.8-10.6 months). Grade 3/4 neutropenia developed in 57.4% of patients, and febrile neutropenia/neutropenic infection in 19.1%. Nonhaematological toxicities were moderate; grade 3/4 diarrhoea occurred in 19.1% of patients, however, was manageable by a dose reduction. There was one possible treatment-related death. In conclusion, weekly docetaxel/irinotecan is a promising outpatient regimen in MGC, with appropriate dose modification.

Adenocarcinoma↗

PubMed2006

Dynamics of space and polarization charges of ferroelectric thin films measured by atomic force microscopy.

Retention behavior and local hysteresis characteristics in Pb(Zr(0.52)Ti(0.48))O(3) (PZT) thin films on Pt electrodes have been investigated by electrostatic force microscopy (EFM). A sol-gel method is used to synthesize PZT thin films and drying conditions are carefully explored over a wide range of temperature. Decay and retention mechanisms of single-poled and reverse-poled regions of the ferroelectric thin films are explained by space charge redistribution. Trapping behavior of space charges is dependent on the nature of interface between ferroelectric thin films and bottom electrodes. Local measurement of polarization-electric field curves by EFM shows inhomogeneous space charge entrapment.

Journal Article↗

PubMed2006

The association of SNP276G>T at adiponectin gene with circulating adiponectin and insulin resistance in response to mild weight loss.

OBJECTIVE: The purpose of this study was to determine whether common single nucleotide polymorphisms (SNPs) at the adiponectin (ADIPOQ) locus influence changes in circulating adiponectin and the features of insulin resistance in response to a weight loss intervention. SUBJECTS: In total, 294 nondiabetic/overweight-obese Koreans participated in a clinical intervention study lasting 12 weeks involving a caloric reduction of -300kcal/day. METHODS: Plasma adiponectin, blood lipids, glucose and insulin concentrations were measured at baseline and after weight loss. Insulin resistance was estimated by homeostasis model assessment insulin resistance (HOMA-IR) derived from fasting glucose and insulin concentrations. We genotyped for three SNPs, 45T>G, 276G>T and -11377C>G. RESULTS: At baseline, HOMA-IR was significantly higher in GG homozygotes than in carriers of the T allele at SNP276G>T of the adiponectin gene (P<0.05). With regard to SNP45T>G and SNP -11377C>G, we did not find any genotype related differences in baseline levels of HOMA-IR and adiponectin. In the 45/276 haplotype test, homozygous for the TG haplotype had significantly lower concentrations of plasma adiponectin (P<0.05). After the 12-week weight loss intervention, the significant decreases in HOMA-IR (P<0.001) and increases in adiponectin (P<0.01) were observed in GG homozygotes at SNP276, which were not shown in carriers of the T allele. Furthermore, there was a significant difference in the decreases in HOMA-IR between the GG homozygotes and carriers of the T allele at SNP276 (P<0.05). Regarding SNP45T>G and SNP -11377C>G, there was no association between SNP45T>G and SNP -11377C>G and decreases in HOMA-IR. In the 45/276 haplotype test, there was a significant difference in changes of adiponectin levels among those with different haplotype combinations (P<0.05). CONCLUSION: The SNP276G>T of the ADIPOQ gene is associated with different responses of circulating adiponectin and insulin resistance to mild weight loss in overweight-obese subjects.

Adiponectin↗

PubMed2006

Genetic variation at the perilipin locus is associated with changes in serum free fatty acids and abdominal fat following mild weight loss.

OBJECTIVE: Perilipin (PLIN) is a class of protein-coating lipid droplets in adipocytes. We aimed to examine the association between common single-nucleotide polymorphisms (SNPs) at PLIN locus with circulating free fatty acid (FFA) and abdominal fat distribution in response to weight loss. METHODS: Non-diabetic/overweight-obese Koreans (n=177) participated in a 12-week calorie restriction (-300kcal/day) program. Seven SNPs (6209T>C, 10076C>G, 10171A>T, 11482G>A, 13042A>G, 13048C>T and 14995A>T), abdominal fat areas (visceral/subcutaneous fat areas at 1st lumbar and 4th lumbar levels), serum lipids, glucose, insulin, FFA, oxidized low-density lipoprotein (LDL) and urinary 8-epi-prostaglandin F(2alpha) (PGF(2alpha)) were examined. RESULTS: Single-nucleotide polymorphisms 10076C>G/10171A>T showed the strongest positive linkage disequilibrium (LD) (D'=0.923, R (2)=0.839, P<0.001) and SNPs11482G>A/14995A>T showed moderate positive LD (D'=0.824, R (2)=0.578, P<0.001). Calorie restriction induced 4.6% weight loss with significant abdominal fat reduction. In response to weight loss, subjects with nCA/nCA haplotypes at SNPs 10076C>G/10171A>T showed greater reduction in FFA levels than those with CA/CA haplotype (CA/CA: C/C at SNP 10076 and A/A at SNP 10171, nCA: non-CA haplotype carrier). On the other hand, subjects with nGA/nGA haplotype at SNPs 11482G>A/14995A>T had increased FFA levels with a rapid loss in abdominal fat, whereas GA/GA haplotype carriers had reduction in FFA levels. These results still remained significant after adjusting for age, gender and BMI. Prostaglandin F(2alpha) and oxidized LDL were also more reduced in GA/GA haplotype carriers than in nGA haplotype carriers. This effect remained significant after adjusting for baseline level, age, gender and BMI. Paradoxically, nGA haplotype carriers had increased levels of urinary PGF(2alpha) after weight reduction. CONCLUSION: Fasting plasma FFA changes following a modest weight loss in overweight-obese subjects are influenced by the genetic variability at the PLIN locus. Furthermore, circulating FFA changes rather than body fat itself may determine changes in lipid peroxides such as urinary PGF(2alpha) and oxidized LDL.

Adult↗

PubMed2006

Spinal metastasis from cranial meningeal hemangiopericytomas.

Spine metastasis from cranial meningeal hemangiopericytomas are extremely rare, with five surgically verified cases. We describe a case of a 55-year-old female diagnosed with metastatic hemangiopericytoma to the cervical spine 78 months after the first operation. Because of the long latency period, aggressive spinal surveillance should be advocated along with repeated bone scintigraphy and MRI.

Cervical Vertebrae↗

PubMed2006

Impulsive solvent heating probed by picosecond x-ray diffraction.

The time-resolved diffraction signal from a laser-excited solution has three principal components: the solute-only term, the solute-solvent cross term, and the solvent-only term. The last term is very sensitive to the thermodynamic state of the bulk solvent, which may change during a chemical reaction due to energy transfer from light-absorbing solute molecules to the surrounding solvent molecules and the following relaxation to equilibrium with the environment around the scattering volume. The volume expansion coefficient alpha for a liquid is typically approximately 1 x 10(-3) K(-1), which is about 1000 times greater than for a solid. Hence solvent scattering is a very sensitive on-line thermometer. The decomposition of the scattered x-ray signal has so far been aided by molecular dynamics (MD) simulations, a method capable of simulating the solvent response as well as the solute term and solute/solvent cross terms for the data analysis. Here we present an experimental procedure, applicable to most hydrogen containing solvents, that directly measures the solvent response to a transient temperature rise. The overtone modes of OH stretching and CH3 asymmetric stretching in liquid methanol were excited by near-infrared femtosecond laser pulses at 1.5 and 1.7 microm and the ensuing hydrodynamics, induced by the transfer of heat from a subset of excited CH3OH* to the bulk and the subsequent thermal expansion, were probed by 100 ps x-ray pulses from a synchrotron. The time-resolved data allowed us to extract two key differentials: the change in the solvent diffraction from a temperature change at constant density, seen at a very short time delay approximately 100 ps, and a term from a change in density at constant temperature. The latter term becomes relevant at later times approximately 1 mus when the bulk of liquid expands to accommodate its new temperature at ambient pressure. These two terms are the principal building blocks in the hydrodynamic equation of state, and they are needed in a self-consistent reconstruction of the solvent response during a chemical reaction. We compare the experimental solvent terms with those from MD simulations. The use of experimentally determined solvent differentials greatly improved the quality of global fits when applied to the time-resolved data for C2H4I2 dissolved in methanol.

Chemistry, Physical↗

PubMed2006

Weight loss effect on inflammation and LDL oxidation in metabolically healthy but obese (MHO) individuals: low inflammation and LDL oxidation in MHO women.

OBJECTIVE: Recently, a subtype of obesity characterized as a metabolically healthy but obese (MHO) individual has been identified. However, limited data are available on these MHO individuals' metabolic and inflammatory profiles, and the effect of weight loss on these profiles. We investigated metabolic and inflammatory markers in MHO women to determine the effects of a 12-week weight loss on those markers. SUBJECTS: One hundred and twenty-nine overweight-obese Korean women participated for 12 weeks in a clinical intervention study involving a 300 kcal/day intake reduction. The subjects were divided into two groups: MHO and metabolically abnormal obese (MAO) individuals. METHODS: Computed tomography was performed. C-reactive protein (CRP), interkeukin-6 (IL-6) and oxidized low-density lipoprotein (LDL), as well as blood lipids, glucose and insulin concentrations were determined at baseline and after weight loss. RESULTS: At baseline, plasma CRP (P<0.001), IL-6 (P<0.05) and oxidized LDL (P<0.001) levels were significantly lower in the MHO group than in the MAO group. Visceral fat at L1 (P<0.005) and visceral fat at L4 (P<0.001) were significantly lower in the MHO group than in the MAO group. The treatment induced weight loss averaging 3.11% of initial body weight, and the degree of weight loss between the two groups was similar. Visceral fat at L1 and L4 was reduced from its initial values by 3.2 and 5.4%, respectively, after weight loss. The levels of CRP (P<0.05) and oxidized LDL (P<0.01) were significantly reduced in the MAO group after the 12-week weight loss, whereas these effects were not seen in the MHO group. CONCLUSIONS: Our results showed that MHO individuals exhibited lower visceral fat accumulation and more favorable metabolic and inflammatory states than MAO individuals. After a 12-week weight loss program, significant reductions in blood lipids, CRP and oxidized LDL levels were observed in MAO individuals. However, there was no measurable effect of weight loss on lipid profiles and inflammation in MHO individuals, indicating differing effects of weight loss on these markers between MAO and MHO groups.

Abdomen↗