Ji Ung Park

Strong and Biostable Hyaluronic Acid–Calcium Phosphate Nanocomposite Hydrogel via in Situ Precipitation Process

Hyaluronic acid (HAc) hydrogel exhibits excellent biocompatibility, but it has limited biomedical application due to its poor biomechanical properties as well as too-fast enzymatic degradation. In this study, we have developed an in situ precipitation process for the fabrication of a HAc-calcium phosphate nanocomposite hydrogel, after the formation of the glycidyl methacrylate-conjugated HAc (GMHA) hydrogels via photo-cross-linking, to improve the mechanical and biological properties under physiological conditions. In particular, our process facilitates the rapid incorporation of calcium phosphate (CaP) nanoparticles of uniform size and with minimal agglomeration into a polymer matrix, homogeneously. Compared with pure HAc, the nanocomposite hydrogels exhibit improved mechanical behavior. Specifically, the shear modulus is improved by a factor of 4. The biostability of the nanocomposite hydrogel was also significantly improved compared with that of pure HAc hydrogels under both in vitro and in vivo conditions.

Three-Dimensional Pre-Bent Titanium Implant for Concomitant Orbital Floor and Medial Wall Fractures in an East Asian Population

Background The objective of this article is to evaluate clinical outcomes of combined orbital floor and medial wall fracture repair using a three-dimensional pre-bent titanium implant in an East Asian population. Methods Clinical and radiologic data were analyzed for 11 patients with concomitant orbital floor and medial wall fractures. A combined transcaruncular and inferior fornix approach with lateral canthotomy was used for the exposure of fractures. An appropriate three-dimensional preformed titanium implant was selected and inserted according to the characteristics of a given defect. Results Follow-up time ranged from 2 to 6 months (median, 4.07 months). All patients had a successful treatment outcome without any complications. Clinically significant enophthalmos was not observed after treatment. Conclusions Three-dimensional pre-bent titanium implants are appropriate for use in the East Asian population, with a high success rate of anatomic restoration of the orbital volume and prevention of enophthalmos in combined orbital floor and medial wall fracture cases.

Alleviation of capsular formations on silicone implants in rats using biomembrane-mimicking coatings

Despite their popular use in breast augmentation and reconstruction surgeries, the limited biocompatibility of silicone implants can induce severe side effects, including capsular contracture - an excessive foreign body reaction that forms a tight and hard fibrous capsule around the implant. This study examines the effects of using biomembrane-mimicking surface coatings to prevent capsular formations on silicone implants. The covalently attached biomembrane-mimicking polymer, poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC), prevented nonspecific protein adsorption and fibroblast adhesion on the silicone surface. More importantly, in vivo capsule formations around PMPC-grafted silicone implants in rats were significantly thinner and exhibited lower collagen densities and more regular collagen alignments than bare silicone implants. The observed decrease in α-smooth muscle actin also supported the alleviation of capsular formations by the biomembrane-mimicking coating. Decreases in inflammation-related cells, myeloperoxidase and transforming growth factor-β resulted in reduced inflammation in the capsular tissue. The biomembrane-mimicking coatings used on these silicone implants demonstrate great potential for preventing capsular contracture and developing biocompatible materials for various biomedical applications.

Statistical analysis using the OMENS classification in Oriental patients with hemifacial microsomia: a comparative analysis with Western centers.

AbstractThe purpose of this study was to analyze the statistical association between variable clinical phenotypes of the orbit, mandible, ear, nerve, soft tissue (OMENS) classification system in Oriental patients with hemifacial microsomia (HFM) and compare the data of Oriental children with data from other Western centers. One hundred consecutive patients with HFM referred to the Seoul National University Children Hospital were chosen between March 2009 and April 2010. They were classified according to the OMENS classification system, and statistical analyses were performed. The total OMENS scores were correlated significantly with all 5 component scores. In comparison with the previous data of Western centers, the orbit and ear components had statistically higher severity. Our retrospective study in Oriental children demonstrated that the pathophysiology of HFM is a complex process and that the components of HFM have a close relationship. For the ethnic difference, further etiologic studies on the molecular basis are required.

Correction of inverted nipples with the double-track sun-cross running suture technique

Abstract Various techniques have been reported for correcting inverted nipples; however, problems such as incomplete correction, recurrence, scarring and nerve or duct injury persist. To minimise the recurrence rate and reliably attain a well-projected nipple, we developed a technique involving a single suture that runs through both the periphery and the core of the nipple. After the dissection and release of fibrotic connective tissue, an absorbable monofilament suture was passed through the periphery and core to leave double tracks of the suture at all locations, creating the final shape of a cross inside a circle (resembling the sun-cross symbol). Finally, the suture was tied in a purse-string manner to push the nipple outward. We performed this surgery on 34 congenital cases, comprising 29 patients with bilateral inverted nipples, 5 patients with a unilateral inverted nipple and 12 patients with an acquired deformity. During a mean follow-up period of 22.4 months, all of the corrected nipples remained everted without reinvagination. We successfully corrected inverted nipples with the double-track sun-cross running suture technique, which provided long-lasting eversion and created an aesthetically pleasing nipple contour.

An Experimental Model Design for Photoaging.

Abstract Autologous adipose-derived stem cells have shown great promise in applications that treat photodamaged skin. Adipose-derived stem cells also have an antiwrinkle effect; consequently, they have become a topic of primary interest. Nude mice have been used extensively in studies of adipose-derived stem cells, human dermal fibroblasts, and other filler injections. However, a nude mouse model of photoaging has not yet been developed. Thus, we attempted to develop a nude mouse model of photoaging in this study. Materials and Methods: Fourteen, 5-week-old female BALB/c nude mice were irradiated with ultraviolet-B rays, 6 times a week for 6 weeks. The minimum erythema dose was established before the mice underwent ultraviolet irradiation to minimize the inflammation of the irradiated skin and to determine the initial irradiation dosage. The mean sizes of the wrinkled areas of skin and the mean depths of the wrinkles were compared between the study groups using replica analysis. Skin biopsies were performed on the 6th and 10th weeks of the study. Results: The mean sizes of the wrinkled areas of skin and the mean depths of the wrinkles increased significantly in the ultraviolet-B-irradiated nude mice compared with the nonirradiated mice, and the thicknesses of the epidermis and dermis of the skin from the upper and lower back were significantly greater after ultraviolet-B irradiation up to the 6th week of treatment (P < 0.05). Furthermore, the ultraviolet-B-irradiated group demonstrated reduced collagen fiber levels. Conclusions: We have successfully developed a nude mouse model for research into photoaging, and these results indicate that the nude mouse is a suitable model for investigating the development of photoaging.

Acute Calcific Tendinitis in the Distal Interphalangeal Joint.

Acute calcific tendinitis is a form of acute inflammation of the tendon, causing severe pain, swelling, and limited joint motion, and is characterized by radiologic evidence of periarticular calcification. The pathogenesis is not clear, but some believe that calcification may result from tendon hypoxia or a traumatic event [1]. Although it is a self-limited disease, in which periarticular calcification is eventually found to be resolved in radiologic imaging, it is often misdiagnosed, which can lead to unnecessary surgical intervention. It occurs most frequently in the shoulder and wrist, and least frequently in the hand, especially the phalanx [2,3,4]. We encountered a rare case of acute calcific tendinitis in a postmenopausal woman in the distal interphalangeal (DIP) joint and developed an appropriate management plan based on the correct diagnosis. A 72-year-old female patient visited the emergency department due to severe pain in the left fourth finger that had developed three days previously. Simple radiography and ultrasonography were first performed, along with routine laboratory examinations, including C-reactive protein levels. A careful history was taken and a physical examination was then performed with the presumptive diagnosis of acute calcific tendinitis or gout, based on radiographic findings. The patient showed redness, swelling, and local heat and tenderness of the radial side of the DIP joint of the left fourth finger, but denied any history of trauma or other inflammatory disease. The patients history revealed that she used the DIP joint extensively because of her occupation (operating a mill). The initial radiographs showed an ovoid calcification on the radial collateral ligament of the DIP joint of the left fourth finger (Fig. 1), and ultrasonography revealed ovoid hyperechoic calcification (Fig. 2). Her C-reactive protein level was elevated. Based on previous studies of the treatment of acute calcific tendinitis of other regions, an anesthetic agent (2% lidocaine, Huons Co., Seongnam, Korea) and a corticosteroid (Triam, Shinpoong Co., Seoul, Korea) were locally injected into the lesion [3,4]. Nonsteroidal anti-inflammatory drugs (NSAIDs) were administered to the patient, and a short arm splint was applied for immobilization. One day after conservative treatment, the symptoms were dramatically alleviated and simple radiographic findings showed that the appearance of the calcification had become mottled (Fig. 3), and the patients C-reactive protein level decreased gradually. After one week of treatment, the patient experienced a complete resolution of pain and exhibited a full range of motion without difficulty. Follow-up radiographic findings after two months showed spontaneous resolution of the calcification (Fig. 4) [5]. Fig. 1 The initial radiographs showed an ovoid calcification on the radial collateral ligament of the distal interphalangeal joint of the left fourth finger. Fig. 2 Ultrasonography revealed ovoid hyperechoic calcification. Fig. 3 One day after conservative treatment was initiated, simple radiographic findings showed a change from an ovoid calcification to a mottled appearance, which co-occurred with the dramatic alleviation of the symptoms. Fig. 4 Follow-up radiographic findings after two months showed the spontaneous resolution of the calcification. Acute calcific tendinitis of the DIP joint is a rare condition, and, to the best of our knowledge, has not previously been reported in this anatomical location. Careful attention to the history of the patient and simple radiography helped us to diagnose this case of acute calcific tendinitis correctly. Misdiagnosis of this disease can lead to unnecessary surgical treatment and delay symptom relief. Based on reports of this condition in other regions, such as the shoulder, elbow, and wrist, conservative management with NSAIDs and a local injection of an anesthetic agent and a corticosteroid were able to relieve the symptoms dramatically in our patient. In light of our experience, acute calcific tendinitis of the hand should be considered as part of the differential diagnosis of a painful finger joint.

Basaloid Squamous Cell Carcinoma on the Skin of the Hand.

Basaloid squamous cell carcinoma (BSCC), an uncommon tumor with a predilection for the upper aerodigestive tract, is considered a distinct variant of squamous carcinoma due to its unique histological features and aggressive clinical behavior [1,2]. To the best of our knowledge, BSCC with a primary origin in the skin is extremely rare, although metastatic deposits of this type of cancer have been reported on the skin [3,4]. In this report, we present an unusual case of primary BSCC of the skin of the hand. An 89-year-old female presented with an exophytic mass on the dorsum of the proximal phalanx of the right third finger that had exhibited rapid growth. The mass was grossly measured to be approximately 1.5 cm×1.5 cm, with irregularly protruding and ulcerative features (Fig. 1). A punch biopsy was performed by a dermatologist, and the pathology report found malignancy with skin surface necrosis and multifocal tumor cell necrosis. Chest computed tomography and positron emission tomography were performed as part of a metastatic work-up, but no evidence of metastasis was observed. A wide excision was made, with a 1.5-cm peripheral margin, and the sheath of the extensor tendon was removed to ensure the complete removal of the tumor along the deep margin (Fig. 2). All frozen biopsies from the surgical margin were found to be negative, and a venous free flap with a 6-cm×3.5-cm skin paddle was harvested from the ipsilateral forearm. One proximal vein was anastomosed to the distal end of the digital artery, and the other three veins were anastomosed to the digital veins in a retrograde pattern (Fig. 3). No adjuvant chemotherapy or radiation was administered, and the patient was discharged seven days postoperatively. Pathological examination found that the tumor had a basaloid component, with lobules of small closely packed basaloid cells showing unique peripheral palisading and central comedonecrosis. The exaggerated nuclear-to-cytoplasmic ratio of the tumor nests accounted for their basaloid appearance, which suggested a histological diagnosis of BSCC (Fig. 4). When a diagnosis of BSCC is suspected, it is important to evaluate the differential diagnosis with other diseases that have similar pathological or clinical features. A pathologist therefore performed an immunochemical evaluation. Immunohistochemistry, which played a substantive role in the diagnosis, showed a positive response for Ki-67 and p63. Ki-67 is a nuclear protein found during the active phase of the cell cycle, while p63 enables BSCC to be distinguished from adenoid cystic carcinoma [5]. Moreover, other possible diagnoses were excluded through tests for MOC-31, chromogranin, cytokeratin 20, and synaptophysin. MOC-31 is useful in diagnosing adenocarcinoma, and chromogranin is a protein found in endocrine tumors. Cytokeratin 20 and synaptophysin show that a cell is from gastric/intestinal mucosa cells or neuroendocrine cells, respectively. Fig. 1 Photograph of primary basaloid squamous cell carcinoma on the skin of the dorsal side of the right third finger. Fig. 2 Intraoperative photograph after wide excision of the tumor. Fig. 3 Schematic view of venous free flap harvest from the ipsilateral forearm. Fig. 4 Hematoxylin and eosin-stained section, showing a mixture of superficial squamous cells and deep basaloid cells with a more aggressive tendency towards infiltration. The flap healed well, without any postoperative complications, and resulted in a natural contour of the dorsal finger (Fig. 5). During two years of subsequent follow-up, no local recurrence was observed. No signs of metastasis, such as the abnormal hypertrophy of a lymph node, were found. Fig. 5 Postoperative photograph at a two-month follow-up visit. BSCC is recognized to be an aggressive variant of squamous cell carcinoma. It is most frequently found in the head and neck area, especially the upper aerodigestive tract, in areas such as the supraglottic larynx, the base of the tongue, the palate, and the buccal cavity. However, BSCC has also been reported in the esophagus, thymus, anus, and cervix [1]. The differential diagnosis for BSCC includes adenoid cystic carcinoma and small cell carcinoma. Distinguishing BSCC from adenoid cystic carcinoma can be difficult. Immunohistochemical staining is a useful method of distinguishing these two malignancies [5]. Early detection and treatment with a generous safety margin is paramount to reduce the risk of local recurrence and metastasis. After surgical treatment, careful follow-up is important. We report a rare case of primary BSCC on the skin of the hand. BSCC is an uncommon, histologically distinct, high-grade variant of squamous cell carcinoma. This case adds to our knowledge of the clinical presentation and treatment of BSCC.

Influence of modified Furlow double opposing Z-plasty on mandibular growth in Oriental patients with cleft palate and/or lip.

AbstractThe purpose of this study was to statistically analyze mandibular growth disturbance in the Oriental cleft population and compare this with that of non–cleft children through cephalometric analysis. Thirty-six children with cleft palates, repaired using a modification of Furlow double opposing Z-plasty, were chosen. Comparative analyses among 3 types of cleft were performed. Statistical analyses of 8 linear and angular measurements were performed in cleft patients and the non–cleft population using Fisher Z-transformation. Comparative analysis showed no significant difference among the 3 types of cleft. In the Oriental cleft group treated with modified double opposing Z-plasty, the spatial position of the mandible showed significant differences compared with the non–cleft group. A backward inclination of the anterior surface of the mandible and downward rotation of the mandibular body were identified. Some of our results regarding gonial angle and length of the mandibular body conflicted with previous Western studies.