Biomedical subjects

B C Cho

Publications and source records attributed to B C Cho.

32 records · Page 2Linked to original sources

PubMed1998

Treatment of osteonecrosis of the femoral head with free vascularized fibular transfer.

Thirty-one free vascularized fibular bone grafts were performed for treatment of osteonecrosis of the femoral head in 26 patients. Twenty-four men and 2 women ranged in age from 16 to 48 years (mean, 32 years). Twenty-one patients had unilateral disease. Five patients had bilateral disease and underwent staged bilateral free vascularized fibular grafts 3 months apart. Associated etiological factors included alcohol (9 patients), steroid use (7 patients), and trauma (1 patient). The condition was considered idiopathic in the remaining 9 patients. Radiological staging by Ficat included stage I in 1 hip, stage II in 15 hips, stage III in 14 hips, and stage IV in 1 hip. A skin island flap was used for monitoring purposes to check the patency of blood flow to the grafted fibula. One flap failed by venous occlusion and was left as a nonvascularized bone graft. Thirty hips were followed. Pain was relieved in 28 hips (93.3%) and aggravated in 2 hips (6.7%). On radiographic evaluation, 26 hips (86.7%) demonstrated excellent preservation of the femoral head contour. Progressive collapse of the femoral head (>1-2 mm) occurred in two hips, with 1-mm depression in one hip with stage III disease and 2-mm collapse in one hip with stage IV disease. Follow-up ranged from 12 to 40 months (mean, 21 months). In conclusion, even in this relatively short follow-up period, the free vascularized fibular bone graft is an excellent treatment modality for preserving the femoral head and relieving symptoms in patients with osteonecrosis of the femoral head.

Adolescent↗

PubMed1998

Surgical correction of unilateral cleft lip nasal deformity.

Fifty-five patients with unilateral cleft lip nasal deformities were operated on from March 1992 to June 1996. Thirty-one patients were male and 24 were female. Three patients were 2 to 5 years of age, 7 patients were 6 to 10 years old, 12 patients were 11 to 15 years old, 13 were 16 to 20 years old, and 20 were greater than 21 years of age. The average follow-up period was 16 months. Combined operative procedures, depending on the severity of the cleft lip nasal deformity, were the following: (1) a reverse-U incision and Z-plasty for a mild vestibular web, (2) a reverse-U incision and V-Y plasty for a moderate vestibular web, (3) open rhinoplasty incision combined with a reverse-U incision and V-Y plasty for severe flattening or buckling of the cleft lower lateral cartilage, (4) lower lateral cartilage suspension or repositioning with or without an onlay cartilage graft, (5) alar base advancement, (6) bone graft on the piriform aperture, (7) septoplasty and corrective rhinoplasty, and (8) columella lengthening with an auricular composite graft. A nasal splint was applied for 3 to 6 months in every patient to maintain the corrected nostril contour. Most patients were satisfied with their surgical results. We suggest that to achieve a good contour of the nose, bony and cartilaginous deformities should be corrected simultaneously with correction of the soft tissue.

Adolescent↗

PubMed1998

Reduction malarplasty using sliding setback osteotomy.

A prominent malar complex results in a triangular facial shape. When combined with a prominent mandibular angle, the face appear to be aggressive and masculine. Surgical procedures to correct these features are commonly requested by Asian women. Baek introduced reduction malarplasty by under-positioning of the "osteotomized" zygoma. We modified Baek's procedure by sliding the osteotomized zygoma superoposteriorly. The posterior surface is not separated from the soft tissue to preserve the blood supply to the zygoma. Ten patients with prominent zygomas underwent reduction malarplasty from March 1994 through July 1996. Seven patients were female and 3 patients were male. All patients were satisfied with their results. A symmetrical appearance was achieved in all patients. This method provides for precise malar reduction under good exposure. Symmetry of the zygoma is easily achieved. There is no effect on the survival of the malar bone after the procedure because the osteotomized zygoma has its own blood supply on the posterior surface. The masseteric origin is preserved, which ensures minimal cheek drooping after reduction.

Adolescent↗

PubMed1998

The effects of surgical and chemical delay procedures on the survival of arterialized venous flaps in rabbits.

The aim of this study was to investigate the efficacy of a surgical delay procedure and a combined surgical and chemical delay procedure on the survival of arterialized venous flaps. Experimental groups included (1) a control group, (2) a surgical delay (4-day and 7-day delay) group, and (3) a combined surgical and chemical (doxazosin mesylate, nitroglycerine patch) delay group. These groups were further divided into subgroups (n = 10) depending on the delay period and the chemical agents. An arterialized venous flap was created on one ear of each rabbit. In the arterialized venous flap, arterial inflow was provided by anastomosis of the central auricular artery to the anterior branch of the central auricular vein and a venous outflow through the anterior marginal vein. In the control group, the arterialized venous flaps without any delay procedure showed complete necrosis of all flaps. In the surgical delay group, the mean percentage survival of arterialized venous flaps was 36.6 percent in the 4-day delay group and 59.7 percent in the 7-day delay group. In the combined surgical and chemical delay group, a 3-day chemical delay followed by a 4-day simultaneous surgical and chemical delay resulted in mean percentage survival of the arterialized venous flaps of 81.1 percent in the doxazosin mesylate group, 72.8 percent in the nitroglycerine patch group, and 92.9 percent in a combination group of doxazosin mesylate and nitroglycerine patch. A 3-day chemical delay followed by a 7-day simultaneous surgical and chemical delay resulted in mean percentage survival of the arterialized venous flaps of 94 percent in the doxazosin mesylate group, 90.2 percent in the nitroglycerine patch group, and 99 percent in a combination group of doxazosin mesylate and nitroglycerine patch. In conclusion, the surgical delay procedure increased the percentage survival of the arterialized venous flaps in proportion to the delay period. The combination group of surgical and chemical delay procedures had a significantly greater percentage survival than that of the surgical delay group (p < 0.001), and the delay period could be shortened.

Administration, Cutaneous↗

PubMed1997

Free latissimus dorsi muscle transfer using an endoscopic technique.

Endoscopic techniques in plastic surgery have involved aesthetic procedures such as facelift, breast augmentation, abdominoplasty, and placement of tissue expanders. Recently, endoscopic harvest of the donor tissue for free flap transfer has included the omentum, jejunum, latissimus dorsi muscle, and rectus abdominis muscle. Ten patients with a soft-tissue defect in the lower extremity were successfully reconstructed from December 1994 to October 1995 with a free muscle transfer after endoscopic harvest of the latissimus dorsi muscle. Nine patients were male and 1 patient was female. A 5- to 6-cm incision was initially made along the posterior axillary line, allowing direct identification of the thoracodorsal vascular pedicle. The latissimus dorsi muscle was dissected posteriorly until the limits of open dissection were reached, and then the dissection was continued under endoscopic visualization. The largest harvested muscle was 15 x 25 cm in size. Follow-up ranged from 6 to 15 months. We believe that plastic surgeons can take advantage of endoscopic techniques to obtain reliable and safe results, with smaller scars and reduced postoperative donor site morbidity such as pain and wound-healing problems. This technique may prove particularly applicable to women, children, and patients who are prone to hypertrophic scars.

Adolescent↗

PubMed1997

Clinical applications of the delayed arterialized venous flap.

Arterialized venous flaps have been used clinically but still have limited applications for coverage of small surface defects. Varying degrees of necrosis of the larger, arterialized venous flaps remain an unsolved problem. We have treated 13 patients, with acute soft-tissue defects in 9 patients and scar contracture in 4 patients, with surgically or surgically-chemically delayed arterialized venous flaps from 1993 to 1995. There were 9 males and 4 females. The average age of the 13 patients was 34.7 years. Donor sites were the medial calf in 4 patients, the volar surface of the forearm in 6 patients, the dorsum of the foot in 2 patients, and the medial thigh in 1 patient. Before arterialization, surgical delay was done in 9 patients and a combined surgical-chemical delay in 4 patients. There were 12 skin flaps and one composite tendocutaneous flap. The follow-up period ranged from 5 to 28 months, with an average of 15 months. The surviving surface area of the arterialized venous flap was 100% in 10 patients, axial 70% in 1 patient, axial 50% in 1 patient, and total necrosis in the remaining patient. Among the 10 flaps with total survival, the minimal flap size was 6 x 8 cm and the maximal flap size was 14 x 16 cm. Advantages of the delayed arterialized venous flap are (1) developing a larger flap than can be obtained with a pure venous flap or arterialized venous flap and (2) the increased survival rate of the arterialized venous flap, which permits the possibility of using a composite flap. This delayed arterialized venous flap also has all the advantages of the pure venous flap, such as preservation of the main artery of the donor site; thin, nonbulky tissue; and easy elevation without deep dissection. The disadvantage is the requirement of a two-stage operation.

Adult↗

PubMed1996

Effect of topically applied Na-hyaluronan on experimental corneal alkali wound healing.

The effect of topically applied 1% sodium hyaluronate (Na-HA) on the healing of a standardized corneal alkali wound was studied. The healing of the epithelium, stroma, and endothelium was evaluated separately, using quantitative methods. Central corneal alkali wound was produced in one eye of the rabbits by applying a 5.5-mm round filter paper, soaked in 1 N NaOH, for 60 seconds. 1% Na-HA in the treatment group and phosphate buffered saline (PBS) in the control group were given topically 4 times per day for 2 days, 1- and 3-weeks. Epithelial and endothelial healing was assessed morphometrically from standardized photographs and micrographs, respectively. Stromal healing was determined by counting polymorphonuclear leukocytes (PMN) and keratocytes in the central and marginal wound areas. A positive healing influence was observed in the epithelium. In stromal healing, 1% Na-HA treated corneas showed less PMNs and more keratocytes than the control group, suggesting that topically applied 1% Na-HA may suppress the stromal PMN infiltration and enhance the keratocyte repopulation during corneal alkali wound healing. However, no significant difference was found in morphometric evaluation of endothelial healing between the two groups.

Administration, Topical↗

PubMed1995

Mouse chromosomal location of the CCAAT/enhancer binding proteins C/EBP beta (Cebpb), C/EBP delta (Cebpd), and CRP1 (Cebpe).

There are four known members of the C/EBP family of basic region-leucine zipper transcription factors: Cebpa, Cebpb, Cebpd, and Cebpe. Cebpa has previously been mapped to mouse chromosome 7. Here, we show that Cebpb maps to mouse chromosome 2, Cebpd to chromosome 16, and Cebpe to chromosome 14. The assignment of Cebpd to chromosome 16 identifies a new region of homology between mouse chromosome 16 and human chromosome 8.

Animals↗

PubMed1995

Frequent disruption of the Nf1 gene by a novel murine AIDS virus-related provirus in BXH-2 murine myeloid lymphomas.

Evi-2, a common site of viral integration in BXH-2 myeloid lymphomas, is located within a large intron of the Nf1 tumor suppressor gene. Viral integration at Evi-2 appears to induce disease by disrupting normal Nf1 expression. During our attempts to characterize the nature of the proviruses located at Evi-2, we found that approximately half of the proviruses were defective nonecotropic proviruses (A. M. Buchberg, H. G. Bedigian, N. A. Jenkins, and N. G. Copeland, Mol. Cell. Biol. 10:4658-4666, 1990). This was surprising, since most proviruses characterized at other BXH-2 common integration sites are full-length ecotropic viruses. In the studies described here, we found that this defective provirus carries two large deletions, one in pol and one in env, and is structurally related to another murine retrovirus, the murine AIDS retrovirus. By using oligonucleotide probes specific for this defective provirus, designated MRV, we showed that MRV-related proviruses are carried as endogenous germ line proviruses in most inbred strains. In addition, we identified the endogenous MRV provirus that gives rise to the defective proviruses identified at Evi-2. We present a model that accounts for the positive selection of MRV proviruses at Evi-2, which may allow selective identification of common viral integration sites harboring tumor suppressor genes.

Acquired Immunodeficiency Syndrome↗

PubMed1994

Coronary reserve and contractile reserve in crystalloid- and blood-perfused rabbit hearts.

Coronary reserve and contractile reserve were compared between crystalloid-perfused and blood-perfused rabbit hearts at various perfusion pressures (40-110 mmHg). Contractile function of the crystalloid-perfused hearts was dependent on the perfusion pressure, according to Gregg's phenomenon. Developed left ventricular pressure (LVP) increased from 67 +/- 6 mmHg to 121 +/- 5 mmHg and positive dP/dt maximum (dP/dt max) from 1,083 +/- 75 to 2,233 +/- 126 mmHg/s at perfusion pressures between the lowest and highest perfusion pressure. In the blood-perfused hearts, the perfusion pressure-induced changes were less pronounced: developed LVP changed from 107 +/- 11 mmHg to 138 +/- 8 mmHg and dP/dt max from 1,517 +/- 181 to 2,008 +/- 187 mmHg/s. The blood-perfused hearts showed better cardiac function, especially negative dP/dt minimum (dP/dt min), compared to the crystalloid-perfused hearts. Contractile reserve estimated by paired pacing technique was quite independent of the perfusion pressure in the blood-perfused hearts but not in the crystalloid-perfused hearts, and was significantly better in the blood-perfused hearts (e.g., 81% increase of developed LVP with blood perfusion, and 26% increase with crystalloid perfusion at a perfusion pressure of 80 mmHg). Coronary reserve, estimated by reactive hyperemia, was independent of the perfusion pressure in both groups. Coronary reserve was small in the crystalloid-perfused hearts (< 23%) and more than double the control value in the blood-perfused hearts. It is proposed that blood-perfused hearts are more suitable for physiological and pathophysiological studies.

Animals↗

PubMed1994

Results of one-stage penile reconstruction using an innervated radial osteocutaneous flap.

Reconstruction of the penis may be indicated in cases of traumatic or surgical amputation of the penis, congenital absence of the penis, micropenis, male pseudohermaphroditism, or transsexualism. Despite recent advances in microsurgery, which have improved the results of total penile reconstructions to a great extent, this operation remains one of the biggest challenges to reconstructive plastic surgeons. The authors have performed one-stage penile reconstruction in five patients since 1989, using an innervated radial forearm osteocutaneous flap. At follow-up (up to 46 months), all patients showed aesthetically acceptable results and good sensory recovery. The most common complications were related to the urethra, involving two fistulae and one urethral stricture.

Adolescent↗

PubMed1993

Murine chromosomal location of four class III POU transcription factors.

A family of mouse genes encoding class III POU transcription factors consists of four members: Oct-6, Brn-2, Brn-1, and Brn-4. In accordance with mouse nomenclature, these loci have been designated Otf-6, Otf-7, Otf-8, and Otf-9, respectively. While the four genes share a highly conserved class III POU domain, the remaining regions are considerably diverged from each other. The POU domains of these transcription factors recognize the octamer-motif sequence and possess a similar DNA-binding specificity. Chromosomal mapping has demonstrated that the four genes are unlinked: Otf-6 is located on the distal region of chromosome 4, Otf-7 on the proximal region of chromosome 4, Otf-8 on chromosome 1, and Otf-9 on the X chromosome.

Animals↗

PubMed1990

Mast cell growth factor maps near the steel locus on mouse chromosome 10 and is deleted in a number of steel alleles.

Many spontaneous, chemical-induced, and radiation-induced dominant white spotting (W) and steel (Sl) mutations have been identified in the mouse. W and Sl mutations have similar phenotypic effects including deficiencies in pigment cells, germ cells, and blood cells, Numerous studies have suggested that W acts within the affected cell while Sl instead exerts its effects in the extracellular environment. Recent findings demonstrating that W encodes the c-kit proto-oncogene, a tyrosine kinase membrane receptor, have suggested that Sl encodes a ligand for c-kit. In the accompanying article we report the identification and purification of mast cell growth factor (MGF), a c-kit ligand. Here we describe the cloning of sequences encoding MGF. Furthermore, we show that Mgf maps near Sl in the distal region of mouse chromosome 10 and is deleted in a number of Sl alleles. These findings strongly support the notion that Sl encodes the mast cell growth factor.

Alleles↗

PubMed1989

A study of microbial flora of conjunctival sac in newborns.

During the period from July to August 1987, the microbial flora in conjunctival sac of 93 newborns (186 eyes: normal vaginal delivery) and 19 newborns (38 eyes: cesarean section delivery) in nursery of Ewha Womans University Hospital were investigated for isolation and identification of bacteria on delivery day and on two days after birth. The results of the investigation are as follows: 1. Of 186 eyes (normal vaginal delivery), bacterial growth of one species was shown in 40 eyes (21.5%) on delivery day and in 64 eyes (34.4%) on two days after birth. Bacterial growth of two species shown in 10 eyes (5.4%) on delivery day and in 10 eyes (5.4%) on two days after birth. 2. Of 38 eyes (cesarean section delivery), bacterial growth of one species was shown in 2 eyes (5.3%) on delivery day and in 20 eyes (52.6%) on two days after birth. Bacterial growth of two species was shown 2 eyes (5.3%) on two days after birth. 3. Several kinds of bacterial species were isolated in normal vaginal delivery and cesarean section delivery. Staphylococcus epidermidis, Escherichia coli, Staphylococcus aureus were isolated.

Bacteria↗