Biomedical subjects

Chul Park

Publications and source records attributed to Chul Park.

15 recordsLinked to original sources

PubMed2006

Use of an expanded temporoparietal fascial flap technique for total auricular reconstruction.

BACKGROUND: The authors propose an expanded technique of the temporoparietal facial flap of sufficient size to provide complete coverage in a single-stage procedure for the projected three-dimensional autogenous cartilage framework, including the tragus or lobule. METHODS: A temporoparietal fascial flap measuring 9 x 9 cm was prepared and wrapped around an expander. The expander was gradually infused with saline solution. Approximately 6 months after the first operation, a projected three-dimensional auricular framework was covered by the expanded temporoparietal fascial flap. Nine patients underwent total ear reconstruction using the expanded temporoparietal fascial flap technique. Of these, two cases were anotia, five were failed reconstructed microtia, and two were posttraumatic absence of ear. RESULTS: A final aesthetic assessment of the results was analyzed subjectively. Three cases showed excellent results, four cases showed good results, one case showed a fair result, and one case showed a poor result. CONCLUSIONS: This expansion technique is indicated in reconstruction of anotia patients who require longer and wider fascial flaps and in auricular reconstruction patients undergoing microvascular free fascial flap transfer for lessening postoperative vascular obstruction, when microvascular anastomosis is performed on the retroauricular region. The technique is also indicated in salvage auricular reconstruction for patients with an unusual vascular pattern on the temporoparietal fascial flap, or for patients showing a vascular insufficiency of the flap's distal portion after flap elevation.

Adolescent↗

PubMed2006

Acquired cervical syringomyelia secondary to a brainstem meningioma in a maltese dog.

A 15-year-old female maltese was referred to us because of a 3-month history of ataxia, circling, and acute blindness. A mass was noted in the brainstem on brain magnetic resonance images. A cerebellar herniation was also detected on T1-weighted sagittal images. The lateral, third and fourth ventricles and central canal of the cervical spinal cord were enlarged. Based on diagnostic imaging findings, cervical syringomyelia secondary to a brainstem tumor was suspected. The clinical signs were controlled well by lomustine and the dog survived for 8 months after the initial diagnosis. The mass was diagnosed as a meningioma based on histopathological findings. This report describes the clinical findings and imaging characteristics of an acquired syringomyelia resulting from a brainstem meningioma.

Animals↗

PubMed2006

Long-term chemotherapy with lomustine of intracranial meningioma occurring in a miniature schnauzer.

A 14-year-old male miniature schnauzer was referred to us because it was circling to the right. A mass in the diencephalon was noted on brain magnetic resonance images. The dura was thickened with marked linear enhancement after contrast administration. Based on diagnostic image analysis, this lesion strongly suggested meningioma. The patient's symptoms were well controlled by a combination therapy of prednisolone and lomustine (CCNU), and survived for thirteen months after diagnosis. This case was diagnosed as a meningioma based on histopathological findings. This report describes the clinical findings, imaging characteristics, and pathologic features of a diencephalic and mesencephalic meningioma and long-term survival after lomustine and prednisolone therapy.

Animals↗

PubMed2006

The effect of wastewater cations on activated sludge characteristics: effects of aluminum and iron in floc.

Wastewater samples collected from seven wastewater treatment plants (WWTPs) were characterized to assess the impacts of wastewater cations on the activated sludge process. The cations included in this study were sodium (Na+), potassium, ammonium, calcium, magnesium, aluminum (Al), and iron (Fe). Among the selected cations, Al and Fe were of most interest to this study because their role in bioflocculation has not been extensively studied and remains largely unknown. The data showed that WWTPs contained highly varying concentrations of Na+, Al, and Fe in the wastewater and that these cations were responsible for differences between WWTPs as to sludge dewatering rates and effluent quality. In general, a high influent Na+ concentration caused poor sludge dewatering and effluent characteristics. However, when sufficient Al and Fe were present in floc, the deleterious effects of Na+ were offset. The data associated with Al further revealed that waste activated sludge with low Al contained high concentrations of soluble and colloidal biopolymer (protein + polysaccharide), resulting in a high effluent chemical oxygen demand, high conditioning chemical requirements, and poor sludge dewatering properties. These results suggest that Al will improve activated sludge effluent quality by scavenging organic compounds from solution and binding them to floc.

Aluminum Compounds↗

PubMed2006

The digestibility of waste activated sludges.

Laboratory digestion studies using waste activated sludges (WAS) were conducted to compare the digestion performance between anaerobic and aerobic processes. Nine samples of WAS from seven wastewater treatment plants were collected and batch-digested under both anaerobic and aerobic conditions for 30 days at 25 degrees C. The cation content of wastewater (both floc and solution phases) and solution biopolymer (protein and polysaccharide) was measured before and after digestion and compared with volatile solids destruction data. The study revealed that each digestion process was associated with a distinct biopolymer fraction, which accounted for differences in volatile solids reduction under anaerobic and aerobic conditions. The anaerobic digestion data showed strong correlations between soluble protein generation, ammonium production, percent volatile solids reduction, and floc iron (Fe). These data suggest that the amount of volatile solids destroyed by anaerobic digestion depends on the Fe content of floc. In aerobic digestion, polysaccharide accumulated in solution along with calcium and magnesium. For aerobic digestion, correlations between divalent cation release and the production of inorganic nitrogen were found. This implies that divalent cation-bound biopolymer, thought to be lectin-like protein, was the primary organic fraction degraded under aerobic conditions. The results of the study show that the cation content in wastewater is an important indicator of the material that will digest under anaerobic or aerobic conditions and that some of the volatile solids will digest only under either anaerobic or aerobic conditions.

Aerobiosis↗

PubMed2005

Canine exocrine pancreatic insufficiency treated with porcine pancreatic extract.

A 1.8-year-old intact female Maltese dog was presented because of a history of chronic diarrhea, polyphagia, weight loss, and coprophagia. The patient was severely emaciated and evacuated very moist and four-smelling, yellow feces. Fecal stain with Sudan III revealed numerous lipid droplets. Result of fat absorption test showed aldigestion. A definite diagnosis was made based on trypsin-like immunoreactivity assay in serum which was low enough to be diagnosed as an exocrine pancreatic insufficiency. After pancreatic enzyme supplement with porcine pancreatin powder, the clinical signs were disappeared. This case report documents clinical manifestations, diagnostic tools, treatment and efficiency of oral pancreatic enzyme replacement therapy of exocrine pancreatic insufficiency in a Maltese dog.

Animals↗

PubMed2005

A case of adrenal gland dependent hyperadrenocorticism with mitotane therapy in a Yorkshire terrier dog.

Hyperadrenocorticism, a disorder characterized by excessive production of cortisol by the adrenal cortex, is well-recognized in dogs. A 10-year-old, intact male, Yorkshire terrier dog was evaluated because of corneal ulceration and generalized alopecia. Diagnosis was made based on history taking, clinical signs, physical examination, and results of routine laboratory testing (complete blood count, serum biochemical analysis, and urinalysis). In addition, adrenocorticotropic hormone (ACTH) stimulation test and abdominal ultrasonography were also used to diagnose this case. The patient was diagnosed as adrenal gland neoplasia and medical therapy using the adrenocorticolytic agent, mitotane, was initiated. An ACTH stimulation test was performed after initial therapy. After successful induction was obtained, maintenance therapy with mitotane still continued.

Adrenal Gland Neoplasms↗

PubMed2004

Polymerized ion pair amphiphile vesicles with pH-sensitive transformation and controlled release property.

Ion pair amphiphiles (IPA) composed of one proton-deionizable single or double alkyl chain ammonium surfactant and one anionic carboxylate surfactant with polymerizable dithiolane ring are prepared to develop polymerized microcapsules that can recognize pH change and transform itself under basic condition, thus releasing encapsulated materials at the desired point. Combination of pH-sensitivity and polymeric solid structure, if fully developed, endows the IPA vesicle with smart function that is highly valuable in drug delivery application. Reasons for such high pH-sensitive vesicle transformation are sought from combined physical properties such as turbidity, zeta potential, surface tension, and release rate of marker through the vesicle membrane.

Hydrogen-Ion Concentration↗

PubMed2004

A case of nutritional secondary hyperparathyroidism in a Siberian tiger cub.

A three-month-old female Siberian tiger cub with hindlimb ataxia was referred to the veterinary teaching hospital of Konkuk University. The patient was fed only beef without supplementation of calcium and vitamins after weaning. The tiger was presented with ataxia and back pain on digital palpation. In addition, abnormal gait, reluctance to move, and depressed withdrawal reflex were noted at the neurological examination. The overall osteodystrophic change of the lumbosacral vertebrae was observed on the lateral and ventrodorsal view of radiographic examination. And also PTH level was increased in hormonal assay when compared to that of cat reference range. Based on the results of examinations, nutritional secondary hyperparathyroidism was diagnosed. Clinical signs of this patient were improved after administration of vitamin D and calcium. This case demonstrates that nutritional hyperparathyroidism could be occurred in wild animals raised on a meat diet containing imbalanced calcium and phosphate.

Animals↗

PubMed2003

Total ear reconstruction in the devascularized temporoparietal region: II. Use of the omental free flap.

Total ear reconstruction using the omental free flap technique was performed on five patients who presented with a devascularized temporoparietal region. The main indication for this technique was unavailability of the contralateral temporoparietal fascia in those requesting autogenous auricular reconstruction. There were no microvascular failures in the procedures conducted. In one case there was a partial loss of the transferred omentum, which resulted from an inadequate omental tailoring. A normal convoluted auricle was obtained after multistage debulking operations and meticulous postoperative molding. The average follow-up period was 3.4 years. Final aesthetic results were graded as satisfactory in four patients and poor in one patient.

Adult↗

PubMed2002

Balanced auricular reconstruction in dystopic microtia with the presence of the external auditory canal.

This article presents a new repositioning method in dystopic microtia (low-set microtia, anteriorly tilted microtia, or both) with the presence of the external auditory canal. In the case of low-set malformations, the dystopic auricular canal complex was freed from adjacent bony structure, shifted upward, and anchored to the thick periosteum of the suprameatal triangle or the adjacent superior portion of the temporal bone with nonabsorbable sutures. When the auricular vestige was large and dystopia was severe, the complex was shifted with attachment of the temporoparietal fascia on its cranial part. Meanwhile, when the auricular vestige was small and dystopia was mild, the complex was shifted without attachment of the temporoparietal fascia. Then, the ear framework fabricated with autogenous costal cartilage was positioned and wrapped with the temporoparietal fascial flap. In the case of anteriorly tilted malformations, the dystopic complex was freed, shifted posteriorly, and anchored to the periosteum of the suprameatal triangle. Preauricular dead space, resulting from shifting the complex, was obliterated with pieces of costal cartilage. Simultaneously, the ear framework was placed and wrapped with the temporoparietal fascial flap. No skin necrosis of the shifted complexes occurred in any of the cases. In one case, the facial nerve was transected during dissection and reanastomosed. Upward repositioning distances in low-set microtias were between 1 and 3.5 cm. Posteriorly repositioning distances in anteriorly tilted microtias were 2 and 3 cm. Thirteen patients with low-set malformations, two patients with anteriorly tilted malformations, and three patients with low-set and anteriorly tilted malformations underwent reconstructive operations. The new repositioning method is relatively simple, safe, and effective.

Adolescent↗

PubMed2002

The treatment of double disruption of the superior shoulder suspensory complex.

Between January 1997 and March 2000, we treated 13 patients with double disruption of the superior shoulder suspensory complex (SSSC). The mean age of the patients was 42 (20-63) years. All patients had associated chest injuries, but there were no injuries of the brachial plexus or the peripheral nerves. Three patients, whose general condition was poor, were treated conservatively. Five underwent internal fixation of both the clavicular and scapular fractures and five of the clavicle only. We evaluated the clinical results using the Rowe Score after a minimum follow-up of 1 year. All fractures united. The average time to union was 14 weeks for clavicular and 11 for scapular fractures. There was malunion in four of five scapular fractures treated conservatively. A functionally better result was obtained in the surgical group with a mean Rowe Score of 88, compared with the conservative group whose mean score was 77. Surgical treatment for double disruption of the SSSC is a good option, allowing early rehabilitation and giving good functional results.

Adolescent↗

PubMed2002

Anatomy and embryology of the external ear and their clinical correlation.

The vascular anatomy for design and execution of various flaps of the auricular region is outlined with emphasis on clinical correlation. A new classification of various flap compositions from the postauricular region based on histologic and anatomic observations is proposed, together with a corresponding clinical example used in different clinical situations. Sound knowledge of the vascular pattern surrounding the auricle provides immense versatility in performing flap operations in this region. A summary of the controversy and updates on auricular embryology is provided in relation to various congenital malformations.

Adult↗

PubMed2002

Correction of cryptotia using an external stretching device.

An external stretching device was devised for the correction of cryptotia. A total of 27 cases of cryptotia received correction with this device. Patient age ranged from 10 to 40 years. During an earlier trial, patients were corrected with the external stretching device only. To make a definite and permanent projection of the upper ear, the external device had to be applied and maintained for more than 5 months. In some patients pin site infection developed during the treatment, which resulted in cessation of treatment. Recently, for cryptotia with marked cartilage adhesion, surgical release of the adhesion with a skin graft was supplemented with the application of the external stretching device. The device was maintained for 2 months and the long-term follow-up showed excellent outcome with well-maintained projection and a satisfactory auricular shape. The author suggests that the external stretching device is a useful alternative in the correction of cryptotia with severe cartilage adhesion in older children or adults.

Adolescent↗

PubMed2002

A newly defined conchal floor arterial flap for auricular reconstruction.

A conchal floor composite flap pedicled by skin of the helical crus has been well described in the literature. Here the flap is elevated based on the supply by an upper auricular branch of the superficial temporal artery. In this article, a newly defined conchal floor arterial flap is proposed. The flap is based on the main stem of the posterior auricular artery and its venae comitantes. Two types of conchal floor arterial flaps were elevated: a proximally based chondral arterial flap and a distally based chondrocutaneous arterial flap. The proximally based flap was used for earlobe reconstruction, whereas the distally based flap was useful in the reconstruction of the upper auricle. Nine congenital auricular malformations were successfully corrected with this newly defined conchal floor flap procedure. This type of flap is easier to elevate, more reliable, and more versatile than the one currently in use.

Adolescent↗