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Biomedical subjects

Jun Young Lee

Publications and source records attributed to Jun Young Lee.

At least 19 recordsLinked to original sources
PubMed2026

Efficacy and safety of revascularization in patients with chronic limb-threatening ischemia by kidney function.

BACKGROUND: The optimal revascularization strategy for patients with chronic limb-threatening ischemia (CLTI) with chronic kidney disease (CKD) remains unknown. We evaluated whether the efficacy and safety of surgical vs endovascular revascularization differ by kidney function. METHODS: In this post hoc secondary analysis of BEST-CLI trial (NCT02060630), 1,704 patients with CLTI were stratified by baseline estimated glomerular filtration rate (eGFR, mL/min/1.73 m&#xb2;): non-CKD (eGFR &#x2265; 90), mild-moderate CKD (eGFR 45-89), advanced CKD (eGFR < 45 or dialysis). The primary outcome was a composite of major adverse limb events (MALE) or death. We estimated the difference in restricted mean time lost (RMTL, in days) adjusted for inverse probability treatment weights. RESULTS: Surgical revascularization was significantly associated with fewer days with MALE or death in non-CKD (RMTL difference: -127.8 days; 95% CI -176.1, -79.6) and mild-moderate CKD (-63.2 days; 95% CI -104.7, -21.8) but not in advanced CKD (-16.4 days; 95% CI -78.8, 46.0; P interaction = .02). This attenuation reflected a diminishing mortality benefit with more severe CKD (P interaction = .01), whereas the association with fewer days with MALE remained consistent across CKD strata (P interaction = .34). Major adverse cardiovascular events and serious adverse events were more common with more severe CKD but did not differ significantly by treatment. CONCLUSIONS: Surgical vs endovascular revascularization was consistently associated with fewer days with MALE across CKD strata. However, its association with mortality varied by kidney function, attenuating the overall benefit for the composite endpoint of MALE or death. These results support individualized revascularization strategies, but require prospective confirmation. TRIAL REGISTRATION: The BEST CLI trial is registered at ClinicalTrials.gov (NCT02060630).

Humans↗
PubMed2007

Expression of the corticotropin-releasing hormone-proopiomelanocortin axis in the various clinical types of psoriasis.

Psychological stress is known to aggravate inflammatory skin diseases such as atopic dermatitis, psoriasis and contact sensitivity by altering the cellular constituents of the immune system. The skin appendages function dually as prominent targets and sources of the peripheral corticotropin-releasing hormone-proopiomelanocortin (CRH-POMC) axis. In this study, we examined the expression level of CRH-POMC axis constituents in psoriasis, a well-known stress-related inflammatory skin disease. The 15 psoriasis patients and six normal controls were retrospectively selected after extensive review of their clinical records and skin biopsy specimens. We immunohistochemically analysed the expressivity of CRH, adrenocorticotrophic hormone (ACTH) and alpha-melanocyte-stimulating hormone (alpha-MSH) in various types of psoriatic lesions and control skin. A significant increase of CRH expression was observed in psoriatic lesions, which involved the entire epidermis (upper layer in particular), hair follicles and sweat glands compared with controls. Expression of ACTH and alpha-MSH was clearly stimulated in a subset of psoriasis patients compared with controls, but on the whole, lacked statistical significance. The immunoreactivity of CRH, ACTH and alpha-MSH in psoriasis was not dependent on its clinical subtype, duration or number of previous treatments. Compared with the definite increase of CRH expression in psoriasis, the expression of the POMC peptides was heterogenous with no overall significance. From the findings, we suggest that CRH, a key stress hormone, may play an important role in the pathomechanism of psoriasis.

Adolescent↗
PubMed2006

Late-onset eccrine angiomatous hamartoma on the forehead.

A 71-year-old Korean man presented with a solitary erythematous plaque on his forehead (Fig. 1). It was first noticed by the patient 1 year previously and had slowly increased in size over that time. Physical examination revealed a slightly elevated, 1.5 cm x 1.5 cm erythematous plaque on the upper midline of the forehead. Sweating was not evoked by physical work or emotional stress. There was no pain or tenderness associated with the lesion. The patient had no history of trauma to the forehead. Histopathologic examination of the lesion showed increased numbers of eccrine glands, as well as dilated vascular channels in the deep dermis and subcutaneous tissue (Fig. 2). An immunohistochemical study showed that these eccrine glands stained positively for S-100 and carcinoembryonic antigen (CEA), and the vascular channels for the antifactor VIII-related antigens. These findings are consistent with eccrine angiomatous hamartoma. There was no change in the lesion during the 1-year follow-up period.

Aged↗
PubMed2006

Immunoreactivity of corticotropin-releasing hormone, adrenocorticotropic hormone and alpha-melanocyte-stimulating hormone in alopecia areata.

Psychological factors are believed to play a role in the pathogenesis of alopecia areata (AA), a frequently encountered hair disorder. In our study, statistically significant elevation of psychological stress was felt by AA patients prior hair loss compared with control, which was strongly believed contributory to hair loss (t-test, P < 0.01). The corticotropin-releasing hormone (CRH) and proopiomelanocortin (POMC) mRNA have been identified in the basal layer of the epidermis and pilosebaceous units of the normal scalp. And with the recent discovery of melanocytes and dermal fibroblasts capable of corticosterone production, the presence of a local stress response system resembling the hypothalamic-pituitary-adrenal (HPA) axis has been suggested. The local stress response system is involved in regulation of the normal hair cycle, but its precise role in AA is unknown. The influence of a local HPA axis or rather, CRH-POMC axis in AA was investigated by analysing immunohistochemically the expression levels of CRH and POMC peptides, including the adrenocorticotropic hormone (ACTH) and alpha-melanocyte-stimulating hormone (alpha-MSH), in a number of AA lesions and normal scalp (as control). The epidermis and pilosebaceous units of normal scalp stained weakly with CRH, ACTH and alpha-MSH, whereas those from the affected sites of the AA group showed intense expression of the peptides (chi-square test, P < 0.01). The meaning of this enhanced expression and their role in the pathogenesis of AA should be further evaluated in future.

Adolescent↗
PubMed2006

UVB-induced interleukin-18 production is downregulated by tannic acids in human HaCaT keratinocytes.

Tannic acids (TAs) are believed to be the key active components in plants, and are believed to be responsible for their anti-inflammatory, anti-viral effects and chemoprevention of cancer. However, the molecular mechanisms for the action of TA are unclear. This study examined the effects of TA on cutaneous inflammation with a human keratinocyte cell line (HaCaT). Interleukin-18 (IL-18) has multiple effects upon various cells involved in inflammatory response. In this study, the IL-18 mRNA expression and protein levels were reduced by a TA pretreatment. UV radiation can trigger the induction of the p38 mitogen-activated protein kinase (MAPK)-dependent signalling cascade. Immunoprecipitation and Western blot analysis was performed to determine if TA regulate the MAPK signalling pathway. TA significantly inhibited the activation of p38 MAPK and extracellular signal-regulated protein kinases. Moreover, TA-inhibited UVB enhanced the expression of the inflammatory mediators, IL-1, IL-6, tumor necrotic factor-alpha, cyclooxygenase-2 and prostaglandin E(2) in UVB-irradiated HaCaT cells. The topical application of TA on mouse skin treated with UVB irradiation has shown that TA inhibited the formation of erythema. These findings suggest that TA has significant anti-inflammatory effects on the UVB-induced response on the skin and may be a candidate natural compound for the regulation of cutaneous inflammation.

Animals↗
PubMed2006

Basal ganglia shape alterations in bipolar disorder.

OBJECTIVE: Shape differences in the caudate heads and putamen were compared between drug-naive and drug-treated patients with bipolar disorder and healthy comparison subjects by using spherical harmonic (SPHARM) techniques. On the basis of previous studies, the authors hypothesized that the drug-naive patients would exhibit shape differences of the caudate heads and putamen, especially on the right side, relative to the healthy comparison subjects, and that shape differences, relative to healthy comparison subjects, would differ between drug-naive and drug-treated patients. METHOD: Brain magnetic resonance images were acquired from 49 bipolar disorder patients (21 drug-naive and 28 drug-treated patients) and 37 healthy comparison subjects. Volumetric measurements were obtained, and SPHARM descriptions were used to measure between-group radius differences in the surfaces of the caudate heads and putamen. RESULTS: Although no significant between-group volume differences were found in the striatal structures, significant shape differences in the anterior and ventral surfaces of the striatum were observed. Specifically, shape differences, more prominent for the right side, were found for drug-naive bipolar disorder patients, relative to the healthy comparison subjects, but not for drug-treated bipolar disorder subjects. CONCLUSIONS: The findings suggest that drug-naive bipolar disorder patients have shape differences of the striatum, relative to healthy comparison subjects, and that these differences may be modulated by treatment. The findings more generally demonstrate the sensitivity of the SPHARM analytic technique for detecting subtle anatomical shape differences in small brain regions in the absence of volume differences.

Adult↗
PubMed2005

Study of adsorption and decomposition of H2O on Ge(100).

The adsorption and decomposition of water on Ge(100) have been investigated using real-time scanning tunneling microscopy (STM) and density-functional theory (DFT) calculations. The STM results revealed two distinct adsorption features of H2O on Ge(100) corresponding to molecular adsorption and H-OH dissociative adsorption. In the molecular adsorption geometry, H2O molecules are bound to the surface via Ge-O dative bonds between the O atom of H2O and the electrophilic down atom of the Ge dimer. In the dissociative adsorption geometry, the H2O molecule dissociates into H and OH, which bind covalently to a Ge-Ge dimer on Ge(100) in an H-Ge-Ge-OH configuration. The DFT calculations showed that the dissociative adsorption geometry is more stable than the molecular adsorption geometry. This finding is consistent with the STM results, which showed that the dissociative product becomes dominant as the H2O coverage is increased. The simulated STM images agreed very well with the experimental images. In the real-time STM experiments, we also observed a structural transformation of the H2O molecule from the molecular adsorption to the dissociative adsorption geometry.

Journal Article↗
PubMed2005

Double dative bond configuration: pyrimidine on Ge(100).

The adsorption of pyrimidine onto Ge(100) surfaces has been investigated using real-time scanning tunneling microscopy (STM), temperature-programmed desorption (TPD), and density-functional theory (DFT) calculations. Our results show that the adsorbed pyrimidine molecules are tilted about 40 degrees with respect to the Ge surface, and through a Lewis acid-base reaction form bridges between the down-Ge atoms of neighboring Ge dimer rows by double Ge-N dative bonding without loss of aromaticity. For coverages of pyrimidine up to 0.25 ML, a well-ordered c(4x2) structure results from states that appear in STM micrographs as oval-shaped protrusions, which correspond to pyrimidine molecules datively adsorbed on every other dimer. However, above 0.25 ML, the oval-shaped protrusions gradually change into brighter zigzag lines. At 0.50 ML, a p(2x2) structure results from the states that appear in STM as zigzag lines. The zigzag lines are formed by the attachment of pyrimidine molecules to the down-Ge atoms of every Ge dimer. However, the unstable p(2x2) structure eventually reconstructs into a c(4x2) structure due to steric hindrance between the adsorbed pyrimidine molecules after stopping the exposure of pyrimidine to the surface.

Adsorption↗
PubMed2005

Immunohistochemical characterization of cutaneous drug eruptions by STI571.

BACKGROUND: STI571, a selective BCR-ABL tyrosine kinase inhibitor, is a promising new drug for chronic myelogenous leukemia (CML). However, the drug has been reported to be associated with adverse cutaneous drug eruptions with high frequency. OBJECTIVE: In this study, the characteristics of the cutaneous drug eruptions by STI571 were investigated. METHODS: The clinical records of 10 patients diagnosed with drug eruption by STI571 were reviewed. We obtained 10 skin biopsy specimens from patients with drug eruption by STI571, 6 from the antibiotics-induced drug eruption group, and 5 from normal skin (control). Immunohistochemical analysis was performed to detect CD4, CD8, CD56, IL-18, IL-1beta and ICAM-1 expression in the cutaneous drug eruption. RESULTS: Seven out of 10 patients had maculopapular exanthema, 2/10 erythema multiforme, 1/10 urticaria. We analyzed the composition of T-lymphocyte subsets from the infiltrates at the STI571-induced drug eruption site in eight patients. Unlike other drug eruptions, the increase in the CD8 expression was statistically significant, especially in the dermoepidermal junction and the upper dermis (P < 0.01). The enhanced expression of IL-18 and IL-1beta was observed as well. In contrast, ICAM-1 was either weakly positive or negative. CONCLUSION: Drug eruption caused by STI571 was mostly expressed as a maculopapular exanthema. The histopathological findings were similar in drug eruption by antibiotics or STI571. Unlike the drug eruptions caused by antibiotics, where the expression of CD4 was dominant, CD8 was dominant in drug eruptions by STI571. The expression of IL-18 and IL-1beta was increased in both groups. This elevation of IL-18 and IL-1beta may assist in understanding the pathogenesis of cutaneous drug eruption.

Adult↗
PubMed2005

Corticotropin-releasing hormone (CRH) downregulates interleukin-18 expression in human HaCaT keratinocytes by activation of p38 mitogen-activated protein kinase (MAPK) pathway.

It is generally accepted that corticotropin-releasing hormone (CRH) acts as the main coordinator of the central response to stress. Stress or an abnormal response to stressors has been found to modify the evolution of skin disorders, including psoriasis and atopic dermatitis. Nevertheless, the specific pathogenic role of stress remains unknown in skin diseases. Interleukin (IL)-18, a member of the IL-1 family, is a key mediator of peripheral inflammation and host defense responses, and is secreted by human keratinocytes. Here, we investigated the regulatory effect of CRH on expression of IL-18 in skin keratinocytes. Exposure of HaCaT cells to CRH resulted in a reduction of IL-18 mRNA transcripts and its production was in a concentration-dependent manner. In order to investigate whether the mitogen-activated protein kinase (MAPK) signaling pathway is involved in the downregulation of IL-18 production, cells were pre-treated with SB203580, an inhibitor of p38 MAPK, prior to the addition of CRH. This pre-treatment blocked the decrease in IL-18 production. In addition, CRH treatment induced rapid phosphorylation of p38 MAPK. SB203580 were able to inhibit CRH-induced p38 MAPK phosphorylation. CRH also inhibited production of IL-18 in human primary keratinocytes. These results suggest that CRH regulates IL-18 production through the MAPK signaling pathway in human keratinocytes.

Cell Line↗
PubMed2005

Treatment of congenital nevomelanocytic nevi with the CO2 and Q-switched alexandrite lasers.

BACKGROUND: A variety of treatment options exist for the management of congenital nevomelanocytic nevi (CNN). Surgical treatment has been the traditional approach, but scarring and cosmetic problems are common. Recently, lasers have been used to treat CNN because, in some cases, surgical excisions are inadequate owing to their inaccessible location, size, and depth. OBJECTIVE: The effects of the combined use of CO2 laser and Q-switched Alexandrite laser on CNN were evaluated. METHODS: Eleven patients with CNN were enrolled in this study. The surface epithelium was abraded by a CO2 laser. Subsequently, the lesion was treated by a Q-switched alexandrite laser. Repeated treatments were done every 6 weeks. The results were evaluated clinically by both physicians and patients at 2 and 6 weeks after each treatment using a 5-point grade scale. RESULTS: By the end of the treatments, the average improvement scale assessed by the physicians, with a 5-point grade scale, was 3.82 and that of the patients was 3.73. There were no cases of hypertrophic scar or postinflammatory hyperpigmentaton persisting beyond 2 weeks. There were no recurrences during the 2-year follow-up period. CONCLUSION: The combined laser treatment is an effective method for the treatment of CNN. The clinical outcome was favorable; the treatment was safer, less painful, and relatively nonscarring; and there was a quicker recovery period and less of a burden to repeat treatment when necessary compared with conventional treatments.

Adolescent↗
PubMed2004

The relationship between disc degeneration and morphologic changes in the intervertebral foramen of the cervical spine: a cadaveric MRI and CT study.

A cadaveric study was performed to investigate the relationship between disc degeneration and morphological changes in the intervertebral foramen of cervical spine, including the effect on the nerve root. Seven fresh frozen human cadavers were dissected from C1 to T1, preserving the ligaments, capsules, intervertebral disc and the neural structures. The specimens were scanned with MRI and then scanned through CT scan in the upright position. Direct mid-sagittal and 45 degree oblique images were obtained to measure the dimension of the intervertebral disc height, foraminal height, width, area and segmental angles. Disc degeneration was inversely correlated with disc height. There was a significant correlation between disc degeneration and foraminal width (p<0.005) and foraminal area (p< 0.05), but not with foraminal height. Disc height was correlated with foraminal width but not with height. The segmental angles were decreased more in advanced degenerated discs. There was a correlation between nerve root compression and decreased foraminal width and area (p<0.005). This information and critical dimensions of the intervertebral foramen for nerve root compression should help in the diagnosis of foraminal stenosis of the cervical spine in patients presenting with cervical spondylosis and radiculopathy.

Adult↗
PubMed2002

Antioxidative flavonoids from leaves of Carthamus tinctorius.

A total of eight flavonoids (1-8), including a novel quercetin-7-O-(6''-O-acetyl)-beta-D-glucopyranoside (6) and seven known flavonoids, luteolin (1), quercetin (2), luteolin 7-O-beta-D-glucopyranoside (3), luteolin-7-O-(6''-O-acetyl)-beta-D-glucopyranoside (4) quercetin 7-O-beta-D-glucopyranoside (5), acacetin 7-O-beta-D-glucuronide (7) and apigenin-6-C-beta-D-glucopyrano syl-8-C-beta-D-glucopyranoside (8), have been isolated from the leaves of the safflower (Carthamus tinctorius L.) and identified on the basis of spectroscopic and chemical studies. The antioxidative activity of these flavonoids was evaluated against 2-deoxyribose degradation and rat liver microsomal lipid peroxidation induced by hydroxyl radicals generated via a Fenton-type reaction. Among these flavonoids, luteolin-acetyl-glucoside (4) and quercetin-acetyl-glucoside (6) showed potent antioxidative activities against 2-deoxyribose degradation and lipid peroxidation in rat liver microsomes. Luteolin (1), quercetin (2), and their corresponding glycosides (3 & 5) also exhibited strong antioxidative activity, while acacetin glucuronide (7) and apigenin-6,8-di-C-glucoside (8) were relatively less active.

Animals↗