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Hyun Jeong Park

Publications and source records attributed to Hyun Jeong Park.

13 recordsLinked to original sources
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

Establishment of an in vitro culture system for chicken preblastodermal cells.

To develop an alternative source for chicken pluripotent cells, we examined (1) whether undifferentiated preblastodermal cells could be subcultured in vitro for an extended period and (2) how subculturing affected the physiological properties of preblastodermal cells. The average number of preblastodermal cells was 2,397 in stage V embryos and 36,345 in stage VII embryos; stage X embryos had an average of 53,857 blastodermal cells. The average cell size decreased significantly (70.63-18.83 microm in diameter; P < 0.0001) as the embryo grew; this was closely related to a reduction in the size and number of lipid vesicles in the cell cytoplasm. The culture conditions were optimized for the stage V preblastodermal cells and the control stage X blastodermal cells. On STO feeder cells, the preblastodermal cells achieved stable growth in vitro only in HES medium or a mixed medium of the Knockout DMEM and HES media. However, more than 10 passages of preblastodermal cells at intervals of 3-4 days was possible only by using the Knockout/HES mixed medium and BRL cell-conditioned HES medium for the primary cultures and subcultures, respectively. Colony-forming preblastodermal cells had well-delineated cytoplasm, which was positively stained for stem cell-specific markers by anti-stage-specific embryo antigen-1 antibody, periodic acid-Schiff's solution, and alkaline phosphatase. When preblastodermal cells with or without culturing were transferred into the blastodermal cavity of stage X embryos, only in vitro-cultured preblastodermal cells at stage V (4/5 = 80%) and stage VII (2/8 = 25%) induced somatic chimerism in recipient chickens. In conclusion, undifferentiated preblastodermal cells could be subcultured, and only the colony-forming preblastodermal cells that stained positively for stem cell markers could induce somatic chimerism.

Animals↗
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↗
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

Production of quail (Coturnix japonica) germline chimeras by transfer of gonadal primordial germ cells into recipient embryos.

The possibility of producing quail germline chimeras by the transfer of gonadal primordial germ cells (gPGCs) into recipient embryos was investigated. Japanese quail of the black (D: homozygous for the autosomal incomplete dominant gene D) and wild-type plumage (WP: d+/d+) strains were used as donors and recipients, respectively. Gonadal cells were retrieved from the gonads of 5-day-old D embryos, and gPGCs were enriched by magnetism-activated cell sorting. Fresh (noncultured) gPGCs or those isolated after culture for 3 days with gonadal stromal cells present in the mixed cell population were introduced into the dorsal aorta of 2-day-old recipient WP embryos. Hatchability of the recipient embryos was 23.7% (31/131) and 34.4% (31/90) for those transfused with cultured or noncultured gPGCs, respectively. Of the hatched quail, 28 acquired sexual maturity; among these animals, 7.1% (1/14) and 21.4% (3/14) of those that received cultured or noncultured gPGCs, respectively, were proved to be germline chimeras. The percentage of germline transmission to the donor-derived gametes in the chimeras that received cultured and noncultured gPGCs were 1.9 and 2.2-4.7%, respectively. In conclusion, quail gPGCs retrieved from 5-day-old embryos were thus transmitted in the germline after their transfer to quail embryos of a different strain. This property of the gPGCs was not adversely affected by culture for up to 3 days.

Animals↗
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

Increased expression of IL-18 in cutaneous graft-versus-host disease.

Interleukin-18 (IL-18) is an 18-kDa cytokine produced by lipopolysaccharide (LPS)-activated macrophages or Kupffer cells. In addition, IL-18 is also produced by many different types of cells and tissues, including epidermal keratinocytes, the adrenal cortex, and the brain. IL-18 acts on the immune system to increase IFN-gamma production from T and NK cells to enhance NK cell cytotoxicity and to activate Th1 cell proliferation. It is considered that the tissue expression of cytokines and cell adhesion molecules such as ICAM-1 are common in graft-versus-host disease (GVHD). Recent evidence suggests that IL-18 is a cytokine relevant in the pathogenesis of GVHD. Despite the potential importance of IL-18 in GVHD, the distribution of IL-18 production in cutaneous GVHD has not been fully investigated. In this study, the expression of IL-18 in the cutaneous GVHD was investigated. Formalin-fixed, paraffin-embedded tissue sections were obtained, and immunohistochemical analysis was performed to detect IL-18 and ICAM-1 expression according to the acute and chronic GVHD. Immunohistochemical analysis confirmed the enhanced IL-18 expression levels in the early stage (grade 1) of acute GVHD and the late stage (sclerodermoid) of chronic GVHD compared to the other stages. In contrast, the ICAM-1 expression level was constant at all stages. Our findings indicate that IL-18 is a significant pathogenic indicator in cutaneous GVHD, and the tissue expression of IL-18 seems to be associated with the pathogenesis of acute and chronic GVHD.

Chronic Disease↗
PubMed2004

Enriched gonadal migration of donor-derived gonadal primordial germ cells by immunomagnetic cell sorting in birds.

This study was conducted to evaluate whether immunomagnetic treatment could improve the retrieval and migration capacity of avian gonadal primordial germ cells (gPGCs) collected from gonads in 5.5-day-old chick and 5-day-old quail embryos, respectively. Collected gPGCs were loaded into a magnetic-activated cell sorter (MACS) after being conjugated with specific gPGC antibodies and either MACS-treated or non-treated cells in each species were subsequently transferred to the recipient embryos. MACS treatment significantly (P < 0.05) increased the population ratio of gPGCs in gonadal cells retrieved (0.74 to 33.4% in the chicken and 2.68 to 45.1% in the quail). This was due to decreased number of non-gPGCs in total cell population. MACS treatment further enhanced gonadal migration of gPGCs transferred in both species (10% vs. 80-85% in the chicken and 10-15% vs. 70-80% in the quail). Increase in the number of microinjected cells up to 600 cells/embryo did not eliminate such promoting effect. In conclusion, MACS treatment greatly increased the population ratio of avian gPGCs in gonadal cells, resulting improved gonadal migration in recipient embryos.

Animals↗
PubMed2002

Mutations of the p53 and PTCH gene in basal cell carcinomas: UV mutation signature and strand bias.

Mutations of p53 and PTCH gene, two candidate tumor suppressor genes for basal cell carcinoma (BCC), were screened in 15 cases of sporadic BCCs that developed in sun-exposed skin region in a Korean population. p53 and PTCH mutations were detected at a frequency of 33 and 40%, respectively, and the mutations were predominantly UV-signature transition, C-->T transitions at dipyrimidine sites and CC-->TT tandem mutations. In both genes, the most common mutations were missense mutations resulting in amino acid substitution, which is different than the results from Caucasian BCCs where mutations are frequently predicted to make truncated or absent proteins. All mutations, except for one, occurred on the nontranscribed strand where is little efficient removal of UV-induced pyrimidine dimers relative to the transcribed strand. Loss of heterozygocity (LOH) of 9q22 for PTCH loci was found in eight of 15 informative cases of BCCs (53%), but none of the cases were informative for LOH of 17p13 for p53 loci. Not only do our data indicate the key role played by p53 and PTCH in the development of BCCs, these findings also suggest that UVB may significantly contribute to BCC tumorigenesis. Moreover, molecular epidemiology composed of incidence of p53 and PTCH mutations, difference in the type of mutation and repair bias of UV-induced DNA lesions might affect the distinct features of BCCs between different racial population.

Aged↗
PubMedDate not supplied

Constructing and testing a self-help intervention program for high blood pressure control in Korean American seniors--a pilot study.

Although significant progress has been made in the reduction of overall cardiovascular risk factors in the United States during the last decade, controlling high blood pressure (HBP) remains a difficult task for many individuals. In particular, socially disadvantaged groups, such as new immigrants, and ethnic minority groups, such as Korean Americans, continue to struggle with this chronic disease and suffer unnecessary complications. We conducted a quasi-experimental study to test the efficacy of a self-help intervention program for HBP control in first-generation Korean American seniors with HBP. The intervention consisted of 3 concurrently administered components: (1) structured behavioral education on HBP management, (2) home blood pressure (BP) monitoring, and (3) monthly support groups facilitated by a bilingual nurse. Of the 49 Korean American seniors (> or =60 years old) who agreed to participate, 31 received the intervention and completed the follow-up interviews at 6 months. Final analysis of BP outcomes using repeated measures and postintervention data suggested that the self-help intervention was effective in significantly improving the proportion of individuals who achieved BP control (<140/90 mm Hg) and in lowering both systolic and diastolic BP in the sample. Specifically, the BP control rate, which was 29% at baseline, increased at 6 months to 69%. Likewise, the mean systolic and diastolic BP values of 142.7 and 87.1 mm Hg at baseline decreased to 129.3 and 75.3 mm Hg, respectively, after 6 months of follow-up. This improvement of the HBP control rate in the sample highlights the clinical efficacy of the self-help intervention for this traditionally underserved immigrant group.

Aged↗