Biomedical subjects

Woo Chan Park

Publications and source records attributed to Woo Chan Park.

5 recordsLinked to original sources

PubMed2006

Amniotic membrane corrects surgically induced astigmatism.

Human amniotic membrane (AM) has been widely used for the reconstruction of ocular surface. We conducted this study to investigate whether AM shows efficacy in maintaining the correction of astigmatism or not. We performed photoastigmatic refractive keratectomy (PARK) on rabbits and grafted AM on the cornea. The effect of AM on the degree of astigmatism was evaluated by topography and cycloplegic refraction. As will be shown, AM did not show any efficacy in maintaining the correction of astigmatism. On the contrary, AM not only eliminated PARK-induced astigmatism but prevented surgically induced astigmatism. We suggest that AM could be a useful tool for controlling the astigmatism induced by laser refractive surgery. Further clinical study is still left to be elucidated.

Amnion↗

PubMed2005

Application of newly developed amniotic membrane ointment for photorefractive keratectomy in rabbits.

We developed amniotic membrane ointment (AMO), and the effect of instilling the AMO after photorefractive keratectomy (PRK) was investigated with respect to inflammatory cell infiltration into the corneal stroma, apoptosis of keratocytes, and suppression of lipid peroxidation of cellular walls. The PRK procedure was performed on both eyes of 10 white rabbits. One eye of each rabbit (the experimental eye) was instilled with the AMO and the other eye of the rabbit (the control eye) with a base ointment 0, 8 and 16 h after the PRK procedure. Corneal specimens were collected 24 h after the PRK procedure. Hematoxylin-eosin stain and TUNEL assay were conducted to demonstrate polymorphonuclear and apoptotic cells, respectively. To assess lipid peroxidation, immunohistochemical staining with an antibody to malondialdehyde was undertaken. Compared to the control, the cornea instilled with the AMO had significantly less polymorphonuclear cells infiltrating into the corneal stroma as well as keratocytes subjected to apoptosis. These corneas also showed a significantly less extent of lipid peroxidation than the control. These data support that instillation of the AMO effectively reduced the recruitment of polymorphonuclear cells, the induction of apoptosis in keratocytes, and lipid peroxidation induced by PRK. Thus, this study could provide basic data on the clinical application of the AMO in the days ahead.

Amnion↗

PubMed2005

Breast MRI findings after modified radical mastectomy and transverse rectus abdominis myocutaneous flap in patients with breast cancer.

PURPOSE: To evaluate the MRI findings in breast cancer patients who had undergone a modified radical mastectomy (MRM) and a transverse rectus abdominis myocutaneous (TRAM) flap. MATERIALS AND METHODS: MRI was performed on 20 patients who had been diagnosed with breast cancer and had undergone an MRM and TRAM flap. The results were examined in terms of MRI's ability to detect the flap and assess possible postoperative changes and recurrence. In addition, MRI images of the opposite breast were analyzed. Follow-up examinations were carried out on 11 patients, and all changes were assessed. RESULTS: The flap was clearly visualized by MRI in all of the patients. The signal intensity of the flap was equivalent to that of fat. The contact zone between the TRAM flap and the mastectomy site was enhanced after contrast infusion. Postoperative changes, such as skin thickening (n=20), edema (n=2), fluid collection (n=3), hematoma (n=1), and fat necrosis (n=3), were detected. In two patients, artificially inserted fat tissue was identified. On the MRI of the opposite breast, enhancing lesions were detected in seven patients. In one patient with this finding, ductal carcinoma in situ was diagnosed. On the follow-up MRI, a decrease in skin thickening, fat necrosis, and hematoma was detected. CONCLUSION: MRI is an effective method for lesion detection and evaluation of postoperative changes after MRM and TRAM flap, as well as for evaluation of the opposite breast.

Adult↗

PubMed2004

Effect of thermal preconditioning before excimer laser photoablation.

The purposes of this study were to assess the expression patterns of heat shock proteins (Hsps), after eyeball heating or cooling, and to elucidate their relationships with corneal wound healing and intraocular complications after excimer laser treatment. Experimental mice were grouped into three according to local pretreatment type: heating, cooling, and control groups. The preconditioning was to apply saline eyedrops onto the cornea prior to photoablation. Following photoablation, we evaluated corneal wound healing, corneal opacity and lens opacity. Hsp expression patterns were elucidated with Western blot and immunohistochemical staining. The heating and cooling groups recovered more rapidly, and showed less corneal and lens opacity than the control group. In the heating and cooling groups, there were more expressions of Hsps in the cornea and lens than in the control group. These results were confirmed in the Hsp 70.1 knockout mouse model. Our study showed that Hsps were induced by the heating or cooling preconditioning, and appeared to be a major factor in protecting the cornea against serious thermal damage. Induced Hsps also seemed to play an important role in rapid wound healing, and decreased corneal and lens opacity after excimer laser ablation.

Animals↗

PubMed2004

Giant cell malignant fibrous histiocytoma of the breast: a case report.

A case of primary malignant fibrous histiocytoma of the breast is reported. The patient was a 48-yr-old woman with a huge tumor involving almost the entire left breast. The central portion of her left breast was already rotted by extensive necrosis and inflammation. She was treated by radical mastectomy and axillary lymphadenectomy to level I. Pathologic examination supported by an immunohistochemical staining confirmed the tumor as malignant fibrous histiocytoma of giant cell type. Axillary lymph nodes were free from tumor metastasis. She had not taken any postoperative adjuvant therapy. The metastasis to lungs was found 2 months after the operation, and she died within 6 months.

Breast↗