Biomedical subjects

H Lee

Publications and source records attributed to H Lee.

At least 19 recordsLinked to original sources

PubMed2006

Emerging invasive liver abscess caused by K1 serotype Klebsiella pneumoniae in Korea.

OBJECTIVES: The high incidence of invasive liver abscess caused by Klebsiella pneumoniae in Taiwan, contrasted with the rareness of this disease in Western countries, has aroused special interest. There have been few detailed reports from other Asian countries. To investigate a current epidemiology of K. pneumoniae liver abscess in Korea and to determine K serotype distribution in K. pneumoniae strains causing liver abscess, we performed a nationwide prospective study. METHODS: Community-acquired, culture-proven liver abscess cases were enrolled between 2004 and 2005. Etiologies and clinical features were analyzed. K. pneumoniae isolates were serotyped according to K antigen. Meta-analysis was done to determine the time trend of the etiologies of liver abscess in Korea. RESULTS: Out of 371 cases collected prospectively, 290 (78.2%) were caused by K. pneumoniae. Most K. pneumoniae liver abscesses were monomicrobial. Diabetes mellitus was the most common underlying disease (39.9%). Distant metastatic infections were frequently observed (8.7%). magA PCR revealed that 95 (59.4%) out of 160 K. pneumoniae isolates belonged to the K1 serotype. CONCLUSIONS: Our study indicates that K. pneumoniae has emerged as a major etiologic agent of liver abscess in Korea, and these emerging infections seem to be attributable to invasive K. pneumoniae strains with capsular K1 serotype.

Aged↗

PubMed2006

Three fluorescent protein voltage sensors exhibit low plasma membrane expression in mammalian cells.

Three first-generation fluorescent protein voltage sensitive probes (FP-voltage sensors) were characterized in mammalian cells. Flare, a Kv1.4 variant of FlaSh [Siegel MS, Isacoff EY. Neuron 1997;19(October (4)):735-41], SPARC [Ataka K, Pieribone VA. Biophys J 2002;82(January (1 Pt 1)):509-16], and VSFP-1 [Sakai R, Repunte-Canonigo V, Raj CD, Knopfel T. Eur J Neurosci 2001;13(June (12)):2314-18] were expressed, imaged and voltage clamped in HEK 293 cells and in dissociated hippocampal neurons. We were unable to detect a signal in response to changes in membrane potential after averaging16 trials with any of the three constructs. Using the hydrophobic voltage sensitive dye, di8-ANEPPS, as a surface marker, confocal analyses demonstrated poor plasma membrane expression for Flare, SPARC and VSFP-1 in both HEK 293 cells and dissociated hippocampal neurons. Almost all of the expressed FP-voltage sensors reside in internal membranes in both cell types. This internal expression generates a background fluorescence that increases the noise in the optical measurement.

Animals↗

PubMed2006

Genetic heterogeneity of autosomal dominant nonprogressive congenital ataxia.

We studied a family with nonprogressive congenital ataxia (NPCA) previously reported in 1985. Follow-up evaluation documented a nonprogressive course. Older family members developed ataxic spells and vertical oscillopsia triggered by stress and exercise. Linkage analysis using a 10K single-nucleotide polymorphism array found suggestive linkage to four loci on chromosomes 1q44, 5q35.1-35.3, 7q36.2-36.3, and 9q31.2-32 and ruled out linkage to the NPCA locus on 3p, proving genetic heterogeneity for autosomal dominant NPCA.

Adult↗

PubMed2006

Cerebellar infarction presenting isolated vertigo: frequency and vascular topographical patterns.

OBJECTIVE: To determine the frequency of cerebellar infarction mimicking vestibular neuritis (VN), the pattern of clinical presentation, and the territory of the cerebellar infarction when it simulates VN. METHODS: We studied 240 consecutive cases of isolated cerebellar infarction in the territories of the cerebellar arteries diagnosed by brain MRI from the acute stroke registry at the Keimyung University Dongsan Medical Center. RESULTS: We identified 25 patients (10.4%) with isolated cerebellar infarction who had clinical features suggesting VN. Two types of cerebellar infarction simulating VN were found: isolated spontaneous prolonged vertigo with imbalance as a sole manifestation of cerebellar infarction (n = 24) and isolated spontaneous prolonged vertigo with imbalance as an initial manifestation of cerebellar infarction (n = 1) followed by delayed neurologic deficits 2 days after the onset. The cerebellar infarction territory most commonly involved was the medial branch of the posterior inferior cerebellar artery territory (24/25: 96%), followed by the anterior inferior cerebellar artery territory (1/25: 4%). None of patients with infarcts in the territory of the superior cerebellar artery or multiple cerebellar arteries showed isolated spontaneous prolonged vertigo. CONCLUSIONS: Cerebellar infarction simulating vestibular neuritis is more common than previously thought. Early recognition of the pseudo-vestibular neuritis of vascular cause may allow specific management.

Adult↗

PubMed2006

Transient risk factors for acute traumatic hand injuries: a case-crossover study in Hong Kong.

OBJECTIVES: To identify the remediable transient risk factors of occupational hand injuries in Hong Kong in order to guide the development of prevention strategies. METHODS: The case-crossover study design was adopted. Study subjects were workers with acute hand injuries presenting to the government Occupational Medicine Unit for compensation claims within 90 days from the date of injury. Detailed information on exposures to specific transient factors during the 60 minutes prior to the occurrence of the injury, during the same time interval on the day prior to the injury, as well as the usual exposure during the past work-month was obtained through telephone interviews. Both matched-pair interval approach and usual frequency approach were adopted to assess the associations between transient exposures in the workplace and the short-term risk of sustaining a hand injury. RESULTS: A total of 196 injured workers were interviewed. The results of the matched-pair interval analysis matched well with the results obtained using the usual frequency analysis. Seven significant transient risk factors were identified: using malfunctioning equipment/materials, using a different work method, performing an unusual work task, working overtime, feeling ill, being distracted and rushing, with odds ratios ranging from 10.5 to 26.0 in the matched-pair interval analysis and relative risks ranging between 8.0 and 28.3 with the usual frequency analysis. Wearing gloves was found to have an insignificant protective effect on the occurrence of hand injury in both analyses. CONCLUSIONS: Using the case-crossover study design for acute occupational hand injuries, seven transient risk factors that were mostly modifiable were identified. It is suggested that workers and their employers should increase their awareness of these risk factors, and efforts should be made to avoid exposures to these factors by means of engineering and administrative controls supplemented by safety education and training.

Accidents, Occupational↗

PubMed2006

Polycystic ovarian morphology in normal women does not predict the development of polycystic ovary syndrome.

CONTEXT: Polycystic ovarian morphology (PCOM) is present in 25% of normal women in the absence of polycystic ovary syndrome (PCOS); however, the natural history of PCOM is unknown. OBJECTIVE: We hypothesized that the presence of PCOM predisposes the development of PCOS. DESIGN: The study was a longitudinal follow-up study over 8.2 +/- 5.2 yr (mean +/- sd; range 1.7-17.5 yr). SETTING: The study took place in an outpatient setting. SUBJECTS: Women who took part in a previous study as a normal control and had an ultrasound examination (n = 40) participated. INTERVENTION: Subjects underwent an interval menstrual history, physical exam, blood sampling, and repeat ultrasound in the follicular phase. MAIN OUTCOME MEASURE: Development of PCOS was diagnosed by irregular menses and hyperandrogenism, in the absence of other disorders. Changes in ovarian morphology over time were evaluated. RESULTS: At the baseline visit, 23 women (57.5%) had PCOM and 17 (42.5%) had normal ovarian morphology. One subject with PCOM developed irregular menses and presumptive PCOS. Eleven subjects with PCOM no longer met the criteria for PCOM at follow-up. There was no factor that predicted the change to normal ovarian morphology at the follow-up visit. CONCLUSIONS: These data suggest that PCOM in women with regular ovulatory cycles does not commonly predispose the development of PCOS. Although it is unusual to develop PCOM if the ovaries are normal on first assessment, ovaries in women with PCOM no longer meet the criteria for PCOM in approximately half of cases over time.

Adult↗

PubMed2006

Three sequential chemotherapy doublets for the treatment of newly diagnosed advanced müllerian malignancies: the modified triple doublet regimen.

OBJECTIVE: Previously, we reported the use of three sequential doublets (Triple Doublets) in the treatment of women with newly diagnosed and advanced stage müllerian malignancies. The surgically defined negative second look operation (SLO) rate to Triple Doublets was 38%. Modifications were made to this treatment regimen that were predicted to reduce toxicity and possibly increase efficacy. METHODS: Open label two-cohort study. Patients with a new diagnosis of Stages II-IV müllerian malignancy were eligible. After cytoreductive surgery, patients were treated with three sequential doublets including 3 cycles of carboplatin and gemcitabine, and 3 cycles of carboplatin and paclitaxel, and 3 cycles of doxorubicin and topotecan. After therapy, all women were clinically staged and evaluated at SLO if clinical staging was negative for residual disease. Primary endpoints were toxicity and negative SLO rate with rates of 60% and 40% defined a priori in optimally cytoreduced (cohort 1) and suboptimally cytoreduced or Stage IV (cohort 2), respectively. RESULTS: Eighty-five eligible patients were enrolled with a median age of 52 years. Forty-seven and thirty-eight women were in cohorts 1 and 2, respectively. 723 cycles of chemotherapy were delivered with no toxic deaths. Grades 3 and 4 toxicities included neutropenia in 75% of patients and thrombocytopenia in 65% of patients during at least one cycle of therapy. Fever and neutropenia were seen in 3.5% of patients. All Grades 3 and 4 non-hematologic toxicities were seen at a frequency of <10%. Seventy women underwent SLO with a negative SLO rate of 53% with an additional 9% having microscopically positive procedures. Negative SLO rate was 74% in cohort 1 and 36% in cohort 2. CONCLUSIONS: Treatment with the modified triple doublet regimen is tolerable with an encouraging pathologic CR rate.

Adult↗

PubMed2006

Association between tPA therapy and raised early matrix metalloproteinase-9 in acute stroke.

BACKGROUND: Matrix metalloproteinase-9 (MMP9) is expressed in acute ischemic stroke and up-regulated by tissue plasminogen activator (tPA) in animal models. The authors investigated plasma MMP9 and its endogenous inhibitor, tissue inhibitor of metalloproteinase (TIMP1), in tPA-treated and -untreated stroke patients. METHODS: Nonstroke control subjects and consecutive ischemic stroke patients presenting within 8 hours of onset were enrolled. Blood was sampled within 8 hours and at 24 hours, 2 to 5 days and 4 to 6 weeks. MMP9 and TIMP1 were analyzed by ELISA and gel zymography. RESULTS: Fifty-two cases (26 tPA treated, 26 tPA untreated) and 27 nonstroke control subjects were enrolled. Hyperacute MMP9 was elevated in tPA-treated vs tPA-untreated patients (medians 43 vs 28 ng/mL; p = 0.01). tPA therapy independently predicted hyperacute MMP9 after adjustment for stroke severity, volume, and hemorrhagic transformation (p = 0.01). There was a trend toward lower hyperacute TIMP1 levels in tPA-treated vs tPA-untreated patients (p = 0.06). Hyperacute MMP9 was correlated to poor 3-month modified Rankin Scale outcome (r = 0.58, p = 0.0005). CONCLUSION: Tissue plasminogen activator independently predicted plasma matrix metalloproteinase-9 (MMP9) in the first 8 hours after human ischemic stroke. As MMP9 may be an important mediator of hemorrhagic transformation, alternative thrombolytic agents or therapeutic MMP9 inhibition may increase the safety profile of acute stroke thrombolysis.

Aged↗

PubMed2006

Exogenous cytokinin treatment maintains cyclin homeostasis in rice seedlings that show changes of cyclin expression when the photoperiod is rapidly changed.

Cyclin is a fundamental regulator of the plant cell cycle. Five different types of cyclin genes (the A-, B-, C-, D-, and H-types) have been reported in Oryza sativa. However, except for Os;cycA1;1, Os;cycB2;1, and Os;cycB2;2, the mechanisms of expression of these cyclin genes have not yet been studied. The interactions of cyclins with cytokinin, an important trigger for cell cycle regulation, have also not been well studied. Here we used semi-quantitative RT-PCR in rice seedlings to analyze the effect of cytokinin on photomorphogenesis and the expression of six cyclin genes. Fifteen-day-old seedlings were grown in a 16/8 h light/dark cycle and then transferred to either constant light or constant dark. The expression of all the cyclin genes tested, except the C-type, decreased after 1 hour in the dark, but did not change after transfer to the light or when kinetin was added to the medium. Similarly, seedlings grown in the dark had decreased expression of the cyclin genes, except Os;cycB2;2, after transfer to the light, a decrease that was prevented by kinetin treatment. Thus, exogenous cytokinin plays an important role in maintaining homeostasis of cyclin gene expression following rapid changes of photoperiod.

Cyclins↗

PubMed2006

Cost of intensive care unit-acquired bloodstream infections.

Intensive care unit-acquired (ICU-acquired) bloodstream infections (BSI) are an important complication of critical illness. The objective of this study was to quantify the excess length of stay, mortality and cost attributable to ICU-acquired BSI. A matched cohort study was conducted in all adult ICUs in the Calgary Health Region between 1 May 2000 and 30 April 2003. One hundred and forty-four patients with ICU-acquired BSI were matched (1:1) to patients without ICU-acquired BSI. Patients with ICU-acquired BSI had a significantly increased median length of ICU stay {15.5 [interquartile range (IQR) 8-26] days vs 12 [IQR 7-18.5] days, P=0.003} and median costs of hospital care [85,137 dollars (IQR 45,740-131,412 dollars) vs 67,879 dollars (IQR 35,043-115,915 dollars, P=0.02) compared with patients without ICU-acquired BSI. The median excess length of ICU stay was two days and the median cost attributable to ICU-acquired BSI was 12,321 dollars per case. Sixty (42%) of the cases died compared with 37 (26%) of the controls [P=0.002, attributable mortality 16%, 95% confidence interval (CI) 5.9-26.0%]. Patients with ICU-acquired BSI were at increased risk for in-hospital death (odds ratio=2.64, 95%CI 1.40-5.29). Among survivor-matched pairs, the median excess lengths of ICU and hospital stay attributable to development of ICU-acquired BSI were two and 13.5 days, respectively, and the attributable cost due to ICU-acquired BSI was 25,155 dollars per case survivor. Critically ill patients who develop ICU-acquired BSI suffer excess morbidity and mortality, and incur significantly increased healthcare costs. These data support expenditures on infection prevention and control programmes and further research into reducing the impact of these infections.

Aged↗

PubMed2006

Prenatal vitamin C status is associated with placental apoptosis in normal-term human pregnancies.

Pregnancy is associated with increased susceptibility to oxidative stress. Deficiencies in antioxidants during pregnancy and placental oxidant-antioxidant imbalance may impair the development of the fetoplacental unit or the eventual offspring. In order to elucidate the association of prenatal status of vitamin C with the oxidative stress and apoptotic activity in normal full-term placentas, we evaluated the content of placental lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) and the trophoblast apoptotic index in normal-term human pregnancies. Tissue samples of placentas obtained from 80 normal-term pregnancies were categorized into 40 cases with a lower level of prenatal vitamin C (< 8.997 microg/ml) and 40 cases with a higher level of prenatal vitamin C (> or =11.734 microg/ml). We evaluated the placental LOX-1 content and the trophoblast apoptotic index with Western blot analysis and immunohistochemistry, and then determined their correlation with the prenatal status of vitamin C. We confirmed that the trophoblast expression for the endothelial scavenger receptor LOX-1 and the apoptotic activity were significantly lower in the group with a higher prenatal level of vitamin C, indicating that placental oxidative stress and the apoptotic index were associated with the maternal status of vitamin C. We therefore postulate that the maternal status of antioxidant vitamins during pregnancy can affect fetal development.

Adult↗

PubMed2006

Burden of disease attributable to obesity and overweight in Korea.

OBJECTIVE: To estimate the burden of disease attributable to overweight and obesity using disability-adjusted life-year (DALY) in Korea. RESEARCH METHODS: Firstly, overweight and obesity-related diseases and their relative risk (RR) were selected by the systematic review. Secondly, population-attributable fractions (PAFs) were computed by using the formula including RR and the prevalence of exposure (Pe) of overweight and obesity. Thirdly, DALYs of overweight and obesity-related diseases in Korea were estimated. Finally, the attributable burden (AB) of diseases due to overweight and obesity was calculated as the sum of the products from multiplying DALYs of overweight and obesity-related diseases by their PAFs. RESULTS: The disease burden attributable to overweight was 827.1 person years (PYs) overall, 732.6 for men, 922.9 for women per 100,000 persons. The disease burden attributable to obesity was 260.0 PYs overall, 144.2 for men, 377.3 for women. Diabetes attributable to overweight and obesity accounts for highest burden among other diseases in both genders. The disease burden attributable to overweight was 3.2 times higher than that attributable to obesity. CONCLUSION: Most proportion of disease burden attributable to high body mass index (BMI) occurred among those with only moderately raised levels such as overweight, not the extremes such as obesity. It suggests that population-based, public health intervention rather than high-risk group-focused strategies are more effective to reduce the burden of disease attributable to overweight and obesity in Korea.

Adult↗

PubMed2006

Coupling caspase cleavage and ubiquitin-proteasome-dependent degradation of SSRP1 during apoptosis.

Structure-specific recognition protein (SSRP1) is an 87 kDa protein that heterodimerizes with Spt16 to form FACT, a complex initially shown to facilitate chromatin transcription. Despite its crucial roles in transcription and replication, little is known about the dynamics of FACT turnover in vivo. Here, we show that SSRP1 is cleaved during apoptosis by caspase 3 and/or 7 at the DQHD(450) site. Analysis of the resulting fragments suggests that cleavage of SSRP1 generates a truncated, chromatin-associated form of FACT. Furthermore, the N-terminal product is stabilized by proteasome inhibitors and ubiquitylated in cells, suggesting degradation through the ubiquitin-proteasome pathway. These results demonstrate that SSRP1 degradation during apoptosis is a two-step process coupling caspase cleavage and ubiquitin-dependent proteolysis.

Amino Acid Sequence↗

PubMed2006

Nonsurgical treatment of abdominal or pelvic abscess in consecutive patients with Crohn's disease.

BACKGROUND: There is little agreement about the efficacy of nonsurgical treatment for abscess associated with Crohn's disease. Furthermore, there is no study on characteristics of abscess or patient that nonsurgical treatment could be worth trying as initial treatment. AIMS: To evaluate the outcome of nonsurgical treatment in Crohn's disease-related abscess and identify factor leading to failure of nonsurgical treatment of this complication. PATIENTS: Twenty-four patients, who consecutively admitted for Crohn's disease-related abscess to our institution during a 7-year period, underwent nonsurgical treatment as initial therapy. METHODS: Outcome data such as recurrence and intractability, and clinical features were retrospectively analysed. Univariate analysis with patient-related factors and abscess-related factors was performed for risk factor identification. RESULTS: Median follow-up period was 47.5 months. Of the eligible patients, 19 patients were treated medically and 5 patients underwent percutaneous catheter drainage with medical treatment. Overall success rate of nonsurgical treatment in our centre was 66.7%. The cumulative recurrence rate at 7 months was 12.5%. All recurrences occurred within 7 months from complete resolution on follow-up imaging. Univariate analysis showed that the significant factors which lead to failure of nonsurgical treatment were presence of associated fistula and concurrent steroid use (P=0.019 and P=0.019, respectively). CONCLUSION: Nonsurgical treatment can be considered as initial treatment modality for the Crohn's disease-related abscess without concurrent steroid therapy or relevant fistula.

Abdominal Abscess↗

PubMed2006

[Current recommendations for the use of SCIT and SLIT].

Allergen specific immunotherapy (SIT) is the only potentially curative treatment of IgE mediated allergic diseases. To ensure its effective use, many requirements must be met before and during therapy. Before starting immunotherapy, informed consent should be obtained, along with the consideration of the indications and contraindications. SIT should be prescribed and administered only by physicians with experience in allergic disease who are qualified to manage severe anaphylactic reactions. The clinical symptoms and the age of the patients determine the route of application, choice of allergen extracts and the duration of treatment. Numerous products and protocols facilitate an individualised therapy.

Desensitization, Immunologic↗

PubMed2006

An unusual case of neuro-Behçet's disease presenting with reversible basilar artery occlusion.

Neuro-vasculo-Behçet's disease is considered a venous vessel disease generally in the form of cerebral venous thrombosis. Arterial involvement has been rarely reported. We present a patient with neuro-Behçet's disease who developed reversible basilar artery occlusion. To the best of our knowledge, this is the first case of neuro-Behçet's disease presenting with reversible basilar artery occlusion. Behçet's disease should be considered in the differential diagnosis of basilar artery occlusion.

Anti-Inflammatory Agents↗

PubMed2006

Dexamethasone protects primary cultured hepatocytes from death receptor-mediated apoptosis by upregulation of cFLIP.

Dexamethasone (DEX) pretreatment protected hepatocytes from TNF-alpha plus actinomycin D (ActD)-induced apoptosis by suppressing caspase-8 activation and the mitochondria-dependent apoptosis pathway. DEX treatment upregulated cellular FLICE inhibitory protein (cFLIP) expression, but did not alter the protein levels of Bcl-2, Bcl-xL, Mcl-1, and cIAP as well as Akt activation. The increased cFLIP mRNA level by DEX was inhibited by ActD, indicating that DEX upregulates cFLIP expression at the transcriptional step. DEX also inhibited Jo2-mediated hepatocyte apoptosis by blocking the formation of the death-inducing signaling complex and caspase-8 activation. Specific downregulation of cFLIP expression using siRNA reversed the antiapoptotic effect of DEX by increasing caspase-8 activation. Moreover, DEX administration into mice increased cFLIP expression in the liver and prevented Jo2-induced hepatic injury by inhibiting caspase-8 and -3 activities. Our results indicate that DEX exerts a protective role in death receptor-induced in vitro and in vivo hepatocyte apoptosis by upregulating cFLIP expression.

Animals↗

PubMed2006

Magnetic PECA nanoparticles as drug carriers for targeted delivery: synthesis and release characteristics.

Magnetic poly(ethyl-2-cyanoacrylate) (PECA) nanoparticles containing anti-cancer drugs (Cisplatin and Gemcitabine) were prepared by inter-facial polymerization. The spherical nanoparticles (d = 250 +/- 15 nm) with smooth surfaces and moderately uniform size distributions were obtained. The amount of magnetite encapsulated inside the polymer matrix was increased up to 14.26% (w/w) by controlling the initial weight ratio of monomer/magnetite. It was found that the amount of Cisplatin encapsulated in the magnetic nanoparticle is much higher than that of Gemcitabine because Cisplatin (hydrophobic) is highly soluble in the oil phase and encapsulated easier inside nanoparticles compared to Gemcitabine (hydrophilic). The presence of magnetite and its super-paramagnetic characteristic were confirmed by FTIR spectra and VSM. In-vitro experiments of drug release and magnetic mobility under external magnetic field demonstrated that magnetic poly(ethyl-2-cyanoacrylate) (PECA) nanoparticles can be a highly versatile magnetic drug carrier with sustained release behaviour and sufficient magnetic susceptibility.

Cyanoacrylates↗