Biomedical subjects

Moon Hyang Park

Publications and source records attributed to Moon Hyang Park.

10 recordsLinked to original sources

PubMed2006

Tissue engineering of heart valves by recellularization of glutaraldehyde-fixed porcine valves using bone marrow-derived cells.

To increase the biocompatibility and durability of glutaraldehyde (GA)-fixed valves, a biological coating with viable endothelial cells (ECs) has been proposed. However, stable EC layers have not been formed successfully on GA-fixed valves due to their inability to repopulate. In this study, to improve cellular adhesion and proliferation, the GA-fixed prostheses were detoxified by treatment with citric acid to remove free aldehyde groups. Canine bone marrow mononuclear cells (MNCs) were differentiated into EC-like cells and myofibroblast-like cells in vitro. Detoxified prostheses were seeded and recellularized with differentiated bone marrow- derived cells (BMCs) for seven days. Untreated GA-fixed prostheses were used as controls. Cell attachment, proliferation, metabolic activity, and viability were investigated and cell-seeded leaflets were histologically analyzed. On detoxified GA-fixed prostheses, BMC seeding resulted in uninhibited cell proliferation after seven days. In contrast, on untreated GA-fixed prostheses, cell attachment was poor and no viable cells were observed. Positive staining for smooth muscle a-actin, CD31, and proliferating cell nuclear antigen was observed on the luminal side of the detoxified valve leaflets, indicating differentiation and proliferation of the seeded BMCs. These results demonstrate that the treatment of GA-fixed valves with citric acid established a surface more suitable for cellular attachment and proliferation. Engineering heart valves by seeding detoxified GA-fixed biological valve prostheses with BMCs may increase biocompatibility and durability of the prostheses. This method could be utilized as a new approach for the restoration of heart valve structure and function in the treatment of end-stage heart valve disease.

Actins↗

PubMed2006

[Crohn's disease associated with IgA nephropathy].

Crohn's disease is a condition of chronic inflammation potentially involving any location of the alimentary tract from mouth to anus. Numerous extraintestinal manifestations can also be present. Urologic complications of inflammatory bowel disease are seen in up to 25% of patients, but renal parenchymal disease has been rarely reported. IgA nephropathy is recognized worldwide as a most common form of primary glomerulonephritis. Clinical manifestations vary, ranging from microscopic hematuria to nephrotic syndrome. Recently, IgA nephropathy associated with systemic diseases has been reported. We describe a case of a 22 year-old man with Crohn's disease associated with IgA nephropathy. At the age of 8 years, microscopic hematuria appeared. After fourteen years, he presented with melena, mild fever, recurrent oral ulcer, microscopic hematuria and proteinuria. Colonoscopic examination revealed characteristic features of Crohn's disease such as multiple ulcers. Microscopic findings showed superficial ulceration with small noncaseating granulomas. Renal biopsy revealed IgA nephropathy. The patient was treated with oral prednisolone, olsalazine, and metronidazole followed by maintenance therapy with sulfasalazine and azathioprine resulting in clinical improvement of Crohn's disease and IgA nephropathy.

Adult↗

PubMed2005

Fallopian tube prolapse misdiagnosed as vault granulation tissue: a report of three cases.

Prolapse of the fallopian tube into the vagina is an uncommon complication caused by either vaginal or abdominal hysterectomy. Recently, however, we encountered three cases with prolapse of the fallopian tube after abdominal hysterectomy. The patients presented with vaginal bleeding. A red hemorrhagic granular mass, misdiagnosed as vaginal granulation tissue both macroscopically and microscopically, was noted at the apex of vagina. Pathologically, one case was initially diagnosed as vaginal vault granulation tissue, but there were two recurrences after excision. Microscopically, the mass had a papillary or villous outer surface with a complex pattern of tubular and glandular structures, as well as acute and chronic inflammatory infiltrates in the fibrovascular stroma. A typical ciliated tubal type of epithelium was identified, and on immunohistochemical staining for cytokeratin, attenuated epithelial cells were detected. It is necessary to receive a pathologic confirmation by performing vaginal biopsy when fallopian tube prolapse is clinically suspected, thus preventing misdiagnosis.

Adult↗

PubMed2004

Combined therapy of cilazapril and losartan has no additive effects in ameliorating adriamycin-induced glomerulopathy.

AIMS: Effects of the blockade of renin-angiotensin system (RAS), by angiotensin-converting enzyme inhibitor (ACEi), type 1 angiotensin II receptor blocker (ARB), or a combination of both, were evaluated in Adriamycin (ADR)-induced glomerulopathy. METHODS: Male Sprague-Dawley rats (180-250 g) were induced of glomerulopathy by treatment with ADR (2 mg/kg, i.v.). Six weeks later, they were treated with cilazapril (1 mg/kg/day) and/or losartan (10 mg/kg/day) for an additional 6 weeks. RESULTS: The urinary excretion of protein progressively increased following the treatment with ADR, which was prevented by ACEi, ARB, and a combination of both. Similarly, the glomerulopathy assessed by glomerulosclerosis index was also ameliorated by ACEi or ARB. However, combined therapy of both ACEi and ARB was without an additional effect (Control 1.4 +/- 0.4%, ADR 10.7 +/- 2.7%**, ACEi 0.8 +/- 0.4%, ARB 2.6 +/- 1.0%, ACEi+ARB 1.7 +/- 1.5%, ** p < 0.01 vs. Control). The expression of transforming growth factor-beta(1) was increased following the treatment with ADR (1.4 +/- 0.07-fold, p < 0.05 vs. Control), however, the degree of which was similarly blunted by either ACEi, ARB, or the combination of both. The expression of type 1 angiotensin II receptor mRNA increased following the treatment with ADR, the degree of which was further upregulated by ACEi and decreased by ARB to the control level (ADR 1.3 +/- 0.06-fold*, ACEi 1.8 +/- 0.05-fold***, ARB 1.0 +/- 0.04-fold, * p < 0.05 and *** p < 0.001 vs. Control). The combined therapy of ACEi and ARB still showed an upregulation of type 1 angiotensin II receptor mRNA, however, of which degree was mitigated compared with that induced by ACEi alone (ACEi+ARB 1.5 +/- 0.04-fold, ** p < 0.01 vs. Control). On the contrary, the expression of type 2 angiotensin II receptor mRNA was downregulated following the treatment with ADR, which was similarly restored to the control level by ACEi, ARB, and a combination of both (ADR 0.5 +/- 0.08-fold**, ACEi 1.0 +/- 0.06-fold, ARB 1.0 +/- 0.05-fold, ACEi+ARB 1.0 +/- 0.05-fold, ** p < 0.01 vs. Control). CONCLUSION: It is suggested that combined therapy of ACEi and ARB with relatively high or maximal doses of each drug has no additive or synergistic benefits on the progression of ADR-induced glomerulopathy. Effects of RAS blockade may in part be related to differential regulation of type 1 and type 2 angiotensin II receptors.

Angiotensin II Type 1 Receptor Blockers↗

PubMed2004

Biocompatibility and biodegradation of cross-linked gelatin/hyaluronic acid sponge in rat subcutaneous tissue.

A gelatin/hyaluronic acid (GH) sponge has been fabricated by freeze-drying and cross-linking. The GH sponge was insoluble when cross-linked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. The morphologies of sponges were investigated using a field emission scanning electron microscope. The porosity of the GH sponge increased with hyaluronic acid content. The GH sponge was biodegradable, as evidenced by implantation in Wistar rat subcutaneous connective tissue. Fibroblasts infiltrated into the sponge matrix, and regenerated collagen in the matrix to a level of 25% by 15 days after surgery. The GH73 sponge induced an acute inflammatory response compared with the GH91 sponge. This inflammatory response could have been stimulated by the presence of hyaluronic acid up to Day 10, as it decreased afterwards. The C-reactive protein of blood samples also indicated the same result. The blood tests and histological results show that GH sponges have good biocompatibility and low antigenicity for tissue engineering scaffolds.

Animals↗

PubMed2004

Basal cell adenoma in the parotid gland: CT and MR findings.

Basal cell adenoma is a rare benign salivary gland epithelial tumor, usually involving the parotid gland. We report CT and MR findings of three cases with basal cell adenoma occurring in the parotid gland. The three cases presented here demonstrate a well-circumscribed tumor, which showed a cystic and solid, or the pure solid mass. They were well enhanced after contrast matter injection. The solid portion of the mass was isoattenuated at CT, with intermediate signal intensity on T1- and T2-weighted MR images. Its cystic portion was hyperintense on both T1- and T2-weighted MR images. It had a hypointense rim on T2-weighted image.

Adenoma↗

PubMed2003

Bio-artificial skin composed of gelatin and (1-->3), (1-->6)-beta-glucan.

Porous scaffolds composed of gelatin and beta-glucan were prepared using the freeze-drying method. The scaffold had an inter-connected pore structure with average pore size of 90-150 microm. Results for the contact angle and cell attachment revealed that a high gelatin content was suitable for cellular attachment and distribution in two- or three-dimensional fibroblast cultures, because the gelatin had acidic residues, and arginine-glycine-aspartic acid groups. To prepare a stratified wound dressing to mimic the normal human skin, fibroblasts and keratinocyte cells were isolated from a child's foreskin, and were co-cultured in gelatin/beta-glucan scaffolds were cross-linked using 1-ethyl-(3-3-dimethylaminopropyl) carbodiimide hydrochloride. An in vivo study showed that after 1 week, the artificial dermis containing the fibroblasts enhanced the re-epithelialization of a full-thickness skin defect rather than the acellular scaffold.

Animals↗

PubMed2003

Follicular expression of c-Kit/SCF and inhibin-alpha in mouse ovary during development.

The mechanism of development of the ovarian follicles has been largely unknown. We performed an immunohistochemical (IHC) study to determine the follicular expressions of c-kit, SCF, and inhibin-alpha at different developmental stages in mouse ovary. Ovaries were obtained from 14 and 16 days post coitum and 2, 7, and 21 days post partum (dpp) mice. IHC for c-kit, SCF, and inhibin-alpha was carried out. c-Kit and SCF were expressed on oogonia regardless of the developmental stage. Immunoreactive c-kit and SCF antigens were expressed on oocytes of primordial and primary follicles of neonate mouse ovaries. In 21 dpp mouse ovary, the expression of c-kit/SCF in oocytes gradually decreased as the follicles developed. c-Kit/SCF was expressed strongly in oocytes of preantral follicles and weakly in granulosa and thecal cells. Inhibin-alpha was mainly expressed on granulosa cells of preantral and early antral follicles of the 21 dpp mouse ovaries. These findings suggest that the IHC expression of c-kit/SCF proteins is specific in all developmental stages of ovarian follicles and is decreased after the follicle starts to grow. The expression of inhibin-alpha is negatively correlated with the expression of c-kit/SCF in the ovarian follicles in mice.

Animals↗

PubMed2002

Omental malignant fibrous histiocytoma with a unique rough endoplasmic reticulum inclusion.

The laminated inclusions in the rough endoplasmic reticulum (RER) are peculiar structures seen only in some cases of chondrocytes of pseudoachondroplasia. These ultrastructurally unique organelles have not yet been reported in inflammatory malignant fibrous histiocytoma (MFH). We describe an omental mass showing unique laminated inclusions in the RER in a young man with intra-abdominal inflammatory MFH. The most striking ultrastructural feature was a dilated RER containing a fine granular substance and a more electron-dense material exhibiting an onion skin-like lamellated or maze-like pattern, mimicking that of so-called laminated inclusions. These lamellated inclusions occupied most of the cytoplasm of the tumor cells. We speculate that the ultrastructural finding of the laminated RER inclusion is not specific for cartilage cells, but may represent abnormal accumulation of some kind of glycoprotein material or matrix protein. This granular material may undergo organization to form a peculiar laminated structure, probably due to a metabolic or fixation process. Further study is needed to elucidate the nature of this material.

Adult↗

PubMedDate not supplied

Differential expression of tissue transglutaminase protein in mouse ovarian follicle.

Tissue transglutaminase (tTG) protein begins to accumulate in apoptotic cells and its mRNA is expressed at the onset of apoptotic change. In the present study, we compared tTG expression with the atretic degree of mouse ovarian follicles. The whole-body gamma-irradiated mouse ovaries were collected and immunohistochemistry for tTG and in situ 3'-end labeling (TUNEL) was performed. Based on the identification of atretic follicles with hematoxylin-eosin and TUNEL immunostaining, tTG expression was evaluated and compared between normal (NF) and atretic follicles (AF). The expression of tTG was different among AF depending on the degree of atretic changes. There was a strong association of tTG expression with the follicular apoptotic changes. Among NF, 24% of follicles expressed tTG protein. This value, however, increased up to 66% in atretic follicles. The present results suggest that the follicular expression of tTG is closely related to the degree of follicle atresia. Therefore, the expression of tTG can be used as a useful marker for the identification of atretic follicles in the ovary.

Analysis of Variance↗