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Biomedical subjects

K Y Ahn

Publications and source records attributed to K Y Ahn.

At least 19 recordsLinked to original sources
PubMed2005

Lipid-mediated delivery of brain-specific angiogenesis inhibitor 1 gene reduces corneal neovascularization in an in vivo rabbit model.

Corneal neovascularization, which occurs in many pathologic states of the cornea, reduces the visual acuity. Recently, we found that the extracellular region of brain-specific angiogenesis inhibitor 1 (BAI1-ECR) has antiproliferative activity through functional blocking of alpha(v)beta(5) integrin in endothelial cells. In this study, we investigated the effects of lipid-mediated subconjunctival injection of the BAI1-ECR gene on corneal angiogenesis induced by epithelial debridement by heptanol in the rabbit. When a pEGFP-BAI1-ECR plasmid was given subconjunctivally 1 week after epithelial debridement, green fluorescence was detected in the corneal stroma with expression persisting for 7 days. To test the effect of BAI1-ECR on neovascularization, rabbits were injected with the BAI1-ECR gene or empty vector two or three times at 1-week intervals beginning 1 week after debridement. When measured with biomicroscopy at 1 or 2 weeks after two weekly injections, BAI1-delivered eyes had significantly less neovascularized corneal area than vector-injected ones in both time periods. Similar microscopic results were obtained after three weekly injections of BAI1-ECR. In quantitative histological examination, the BAI1-receiving eyes showed significantly less neovascular area and number of vessels than vector-injected ones. Also, after two weekly injections, BAI1-delivered eyes had decreased neovascularized corneal area equivalent to that of anti-VEGF antibody-injected ones. These results indicate that BAI1-ECR gene delivery effectively reduces experimental corneal neovascularization and suggest that the BAI1-ECR protein can be used as an angiogenesis suppressor in the eye.

Angiogenic Proteins↗
PubMed2001

Cardiac Characteristics of Transgenic Mice Overexpressing Refsum Disease Gene-Associated Protein within the Heart.

Arrhythmia is a common cardiac symptom of Refsum disease. Recently, we identified a novel neuron-specific PAHX-associated protein (PAHX-AP1), which binds to the Refsum disease gene (PAHX). In this report, we developed heart-targeted transgenic (TG) mice under the control of alpha-myosin heavy chain promoter to determine whether cardiac overexpression of PAHX-AP1 provokes cardiac involvement symptoms. Northern and in situ hybridization analyses revealed PAHX-AP1 transcript was overexpressed in TG atrium, especially in the sinoatrial node. TG mice showed tachycardia, and tachyarrhythmia was observed in 20% of TG mice. Isolated TG atria showed higher frequency beating and were more sensitive to aconitine-induced tachyarrhythmia than the wild-type, and 40% of the TG atria showed irregular beating. Action potential duration in TG atrial fiber was shortened much more than the wild-type. Systemic administration of arrhythmogenic agents induced arrhythmia in TG mice, while no arrhythmia with the same dose in nonTG mice. Our results indicate that the chronic atrial tachycardia by overexpressed neuron-specific PAHX-AP1 transgene in atrium may be responsible for the increased susceptibility to arrhythmia.

Action Potentials↗
PubMed2001

Characterization of mouse brain-specific angiogenesis inhibitor 1 (BAI1) and phytanoyl-CoA alpha-hydroxylase-associated protein 1, a novel BAI1-binding protein.

Previously, PAHX-AP1 (PAHX-associated protein 1) was isolated as a novel protein to interact with Refsum disease gene product (phytanoyl-CoA alpha-hydroxylase, PAHX) and specifically expressed in mouse brain. PAHX-AP1 is also suggested to be involved in the development of the central neurologic deficits of Refsum disease. To clarify its function, we have searched for proteins that associate with PAHX-AP1 via yeast two-hybrid system. We found that PAHX-AP1 interacts with the cytoplasmic region of human brain-specific angiogenesis inhibitor 1 (hBAI1), and isolated murine homolog of hBAI1. Structural analysis of the PAHX-AP1 with three reported hBAI-associated proteins (BAP) revealed no homology among them, and we designated PAHX-AP1 as BAP4. The ability of BAP4 to interact with BAI1 was confirmed by pulling-down BAI1 with GST-BAP4 protein and immunoprecipitation study using brain lysate. Northern and Western blot analyses demonstrated a unique pattern of BAI1 expression in the brain. The peak level of BAI1 was observed 10 days after birth. In situ hybridization analyses of the brain showed the same localization of BAI1 as BAP4, such as most neurons of cerebral cortex, hippocampus, and V, VI, VII, VIII, and XII nuclei. Because BAI1 possessed thrombospondin-type 1 repeats in its extracellular region, changes of BAI1 expression were examined in the focal cerebral ischemia model. The BAI1 expression decreased on the ischemic side after 24 h but BAP4 was not changed after the time-course of ischemia. Our results indicate that expression and localization of BAI1 in the brain is correlated with BAP4, and that BAI1 is involved in inhibition of angiogenesis and neuronal differentiation.

Angiogenesis Inhibitors↗
PubMed2001

Nitric oxide synthase gene and protein expression are upregulated by Bacille Calmette-Guérin in the rat bladder.

OBJECTIVE: We hypothesize that Bacille Calmette-Guérin (BCG) may act through the regulation of various isoforms of nitric oxide synthase (NOS) [inducible (iNOS), endothelial (eNOS), and neuronal (nNOS)] genes and protein expression in rat bladder. METHODS: Adult female Sprague-Dawley rats (200-250 g) were injected transurethrally with BCG (22 rats) and phosphate-buffered saline (22 control rats), and after 2, 4, 6, and 12 h, and 1, 2, 3, 5, 7, 10, and 14 days, the bladders were harvested. Normal and BCG-treated rat bladders were analyzed for mRNA expression for iNOS, eNOS, and nNOS by reverse-transcriptase polymerase chain reaction. Protein expression was determined by Western blotting and immunohistochemistry. RESULTS: mRNA expression for iNOS was induced after 2 h of BCG injection in the rat bladder. Gene expression for iNOS was highest at 6 h to 1 day followed by decreased expression, reaching its lowest level at 5 days. eNOS mRNA expression was detected in control bladders, but its level was higher in the BCG-treated animals. nNOS mRNA expression was present in all samples, but did not change after BCG treatment. Western blotting confirmed these findings. Immunohistochemistry analysis demonstrated that eNOS was present mainly in endothelium, while iNOS was detected in stroma and nNOS in epithelium and smooth muscle of the rat bladder. CONCLUSION: The present study demonstrates, for the first time, that BCG treatment up-regulates gene and protein expression of iNOS and eNOS in normal rat bladders, suggesting that BCG action may be mediated through NOS pathways.

Animals↗
PubMed2001

p53 mutation and epidermal growth factor receptor overexpression in glioblastoma.

Recent molecular studies indicate two different genetic pathways leading to the development of glioblastoma; final progression of astrocytoma and de novo formation. To define the mutual relationships of cytogenetic changes in the pathogenesis of glioblastoma, molecular histopathologic alterations of p53 and epidermal growth factor receptor (EGFR) were evaluated by single stranded conformational polymorphion, reverse transcriptase-polymerase chain reaction and immunohistochemical stains in 15 primary and 21 secondary glioblastomas. Mutations in p53 gene and positive immunoreactivity to p53 protein (DO1) were more prevalent in secondary glioblastomas than in primary glioblastomas. A correlation between p53 mutations and p53 immunopositivities in glioblastomas was observed in 83.3% of the cases. All cases with positive p53 immunoreactivities showed p53 mutations; however, 13.9% of glioblastomas with p53 immuno-positivities lacked the relevant mutations. EGFR amplifications were detected in 73.3% of primary glioblastomas and 9.5% of secondary glioblastomas (p<0.001). The concurrence of p53 mutation and EGFR amplification was revealed in only 2 out of 15 primary glioblastomas and none among the secondary glioblastomas. Immunoreactivities for EGFR were noted in 66.7% of primary glioblastomas and in 9.5% of secondary glioblastomas (p<0.001). A correlation between EGFR amplification and EGFR immunopositivity in glioblastomas was observed in 91.7% of the cases. These data indicate that EGFR amplification and p53 mutations are two independent genetic events in the development of glioblastomas.

Adolescent↗
PubMed2001

Comparative study of angiostatic and anti-invasive gene expressions as prognostic factors in gastric cancer.

Genes involving angiogenesis and metastasis play an important role in the progression and infiltration of cancer. We examined the expressions of various angiostatic and potential invasion/metastasis suppressor genes through RT-PCR analyses in 32 gastric cancer specimens with or without distant metastasis. The expressions of the invasion/metastasis suppressor, nm23 and E-cadherin increased much more in the cancer tissue (CT) and metastatic lymph node (MLN) than in the extraneoplastic mucosa (EM) and non-metastatic lymph node (NLN), respectively. The expressions of the angiostatic factor, angiopoietin 2 and thrombospondin 2 increased in the CT and MLN as compared with the EM and NLN, respectively. The newly cloned angiostatic factor, brain-specific angiogenesis inhibitor 1 (BAI1) decreased much more in the CT and MLN than the EM and NLN, respectively. However, BAI1 increased in the CT compared with the EM among the patients with poor prognosis and distant metastasis, such as liver or peritoneum. The expressions of the invasive factor, matrix metalloproteinase-2 and its suppressor, tissue inhibitor metalloproteinase-2 (TIMP-2) increased in the CM as compared with the EM, but the increased expression pattern of these genes in the CT became blunted among the patients with good prognosis. Our results indicate that BAI1 and TIMP-2 expressions in the extraneoplastic mucosa and non-metastatic lymph nodes were not suppressed in the patients with good prognosis, but increased expressions of angiopoietin 2, thrombospondin 2, TIMP-2, nm23 and E-cadherin in the tumor tissue did not lead to a long survival after operation. It is suggested that the extent of BAI1 and TIMP-2 expression in the gastric mucosa may be an important prognostic factor for predicting survival in gastric cancer.

Actins↗
PubMed2001

Overexpressed human RAD50 exhibits cell death in a p21(WAF1/CIP1)-dependent manner: its potential utility in local gene therapy of tumor.

Previously, mouse RAD50, one of the mammalian DNA recombination repair genes, was reported to have limited epitopic homology to p53. Here we report the functional characteristics of overexpressed human RAD50 (hRAD50). Transient transfection of hRAD50 in several cultured cells caused cytotoxicity. We established tetracycline-regulated, stable hRAD50 expression systems in SaOS-2 cells, which retain mutated p53, and in HeLa cells. After tetracycline withdrawal, cell death and multinucleated giant cells were observed with increased hRAD50 expression, and p21(WAF1/CIP1) but not p53 was increased. Transient transfection of hRAD50 in HCT116 p21(-/-) cells caused no cytotoxicity, but there was a significantly decreased survival rate in p21(+/+) cells. These cytotoxic effects of overexpressed hRAD50 in HeLa, SaOS-2, and HCT116 p21(+/+) cells were partially blocked by pretreatment of cells with N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone, a pan-caspase inhibitor. When the hRAD50 expression cDNA was injected intratumorally with liposomes, it regressed or delayed tumor development in the animal model and nitric oxide synthase expression was induced in the tumor tissues that had regressed. Our results indicate that overexpressed hRAD50 has an antiproliferation activity in vitro and in vivo in a p21-dependent manner.

Acid Anhydride Hydrolases↗
PubMed2000

Identification of a brain specific protein that associates with a refsum disease gene product, phytanoyl-CoA alpha-hydroxylase.

Refsum disease is an autosomal recessive neurologic disorder of the lipid metabolism. Major diagnostic clinical findings include retinitis pigmentosa, peripheral polyneuropathy, cerebellar ataxia, increased cerebrospinal fluid protein without pleocytosis, nerve deafness, and cardiac involvement. We have identified a novel protein (PAHX-AP #1) associated with phytanoyl-CoA alpha-hydroxylase (PAHX), a Refsum disease gene product, using the yeast-based two-hybrid assay. The middle portion (amino acids 83-264) of PAHX was used as a bait and a mouse brain cDNA library was searched. The ability of PAHX-AP #1 to interact with PAHX was confirmed using immunoprecipitation and Western blot studies in NIH3T3 cells which stably expressed both PAHX and PAHX-AP #1. Northern and Western blot analyses demonstrated a unique pattern of developmental PAHX-AP #1 expression which was targeted to the adult brain, but ubiquitous expressions of PAHX were observed in all examined tissues. In situ hybridization analyses of the brain showed specific localization of PAHX-AP #1 to the supragranular layer in the cerebral cortex, dentate gyrus, hippocampus, Purkinje cell layer, deep cerebellar nucleus, trigeminal nucleus, abducent nucleus, facial nucleus, cochlear and vestibular nucleus, ganglion cell and nuclear layer of the retina. These data indicate that localization of PAHX-AP #1 in the brain is correlated with central neurologic symptoms of Refsum disease such as retinitis pigmentosa, cerebellar ataxia, nerve deafness and suggest that PAHX-AP #1 may be involved in the development of the central neurologic deficits of Refsum disease.

3T3 Cells↗
PubMed2000

Peroxiredoxin is ubiquitously expressed in rat skin: isotype-specific expression in the epidermis and hair follicle.

Peroxiredoxins are a family of peroxidases that are ubiquitously and abundantly expressed in mammalian tissues; however, comparatively less is known about their expression in the skin. In this study, we examined the expression of three isotypes of peroxiredoxins (I-III) in rat skin. Western blot analyses showed strong expression of peroxiredoxins I-III in the epidermis and dermis of intact skin. Additionally, they were expressed in cultured rat keratinocytes and fibroblasts. Confocal image analyses revealed that peroxiredoxin II was present in the cytoplasm as a diffuse, reticulated pattern. In immunohistochemical staining of rat skin, peroxiredoxin expression was mainly localized to the epidermis, hair follicles, and sebaceous glands. In the epidermis, peroxiredoxins I and II were expressed in all layers with a gradient of increasing expression to the granular layer. In contrast, peroxiredoxin III was expressed in all layers with a gradient of expression decreasing to the granular layer. In the hair follicle, peroxiredoxins I-III were mainly expressed in the outer root sheath, except peroxiredoxin II, which was strongly expressed in the inner root sheath. In situ hybridization showed that mRNA expression was commensurate with the level of protein. Ultraviolet B radiation increased peroxiredoxin II expression in rat skin within 15 min after irradiation. From this study we conclude that peroxiredoxin isoforms are ubiquitously expressed in rat skin, and expression of at least peroxiredoxin II can be regulated by ultraviolet irradiation as a peroxidase in the skin. J Invest Dermatol 115:1108-1114 2000

Animals↗
PubMed2000

Diminished adenylate cyclase activity and aquaporin 2 expression in acute renal failure rats.

BACKGROUND: The present study was aimed at investigating the changes of aquaporin 2 (AQP2) expression and its underlying mechanisms in ischemic acute renal failure (ARF). METHODS: ARF was induced by clamping the both renal arteries for 60 minutes in rats. Two or seven days later, AQP2 expression and trafficking were determined in the kidney by Western blot analysis and immunohistochemistry. The activity of adenylate cyclase was also measured. RESULTS: The urinary flow rates in ARF-2 and ARF-7 day were significantly increased in association with decreases of urine osmolality. While there was decreased expression of AQP2 in the cortex, outer medulla, and inner medulla in ARF, it was most pronounced in the outer medulla. The AQP2 expression was reduced in the apical membrane-enriched fraction as well the subapical vesicle-enriched fraction in ARF; however, the degree was greater in the former than in the latter. Immunohistochemical study also showed a markedly decreased expression of AQP2 in the collecting duct in ARF. cAMP generation in response to arginine vasopressin (AVP) in the kidney was attenuated in ARF, most prominently in the outer medulla. cAMP generation in the outer medulla in response to forskolin was not affected, but sodium fluoride was significantly blunted in ARF. CONCLUSIONS: The AVP-stimulated adenylate cyclase activity is impaired in ARF, secondary to a defect at the level of the G protein. The expression of AQP2 was reduced as a consequence, which may in part account for urinary concentration defect in ARF.

Acute Kidney Injury↗
PubMed2000

Botulinum toxin A for the treatment of facial hyperkinetic wrinkle lines in Koreans.

There are a number of different causes for facial wrinkle lines, such as aging, gravity, and chronic pulling of mimetic muscles on the face. Among these, pulling by mimetic muscles on the skin not only involves facial expression but also has a great role in forming facial wrinkle lines as a result of repetitive action, such as dynamic or hyperkinetic wrinkle lines. Botulinum toxin A is currently being used for eliminating facial hyperkinetic wrinkles by causing paralysis of the underlying mimetic muscles. Because there are some histologic differences between Asians and Caucasians, such as thick dermis and more abundant collagen fiber, etc., the chronic pulling by mimetic muscles on the skin is expected to affect facial wrinkles differently. Therefore, the purpose of this study was to determine the efficacy of botulinum toxin A injection in eliminating facial hyperkinetic wrinkle lines among Korean patients. This study included 38 patients and 59 injection sessions from January of 1996 to April of 1997. We used Botox containing 100 U. Toxin was diluted with 4 ml of sterile normal saline and yielded 2.5 U for each 0.1 cc. A dose of 5 to 10 U was used in each muscle. Ages ranged from 26 to 56 years. There were 33 women and 5 men included in this study. Thirty-two of the patients were followed from 3 months up to 12 months after injections. The number of injection sessions that were performed on each patient was as follows: one session, 23 patients; two sessions, 10 patients; three sessions, 4 patients; four sessions, 1 patient. The number of injections per target site among these 38 patients was as follows: lateral canthal area, 33; glabellar area, 9; forehead, 9; nasal dorsum, 5. The most common duration of effective response was about 4 months, but in eight patients the period was over 5 months. After the response, complete recovery took about 1 or 2 months. Two patients felt unsatisfied, 5 patients felt slightly improved, and 25 patients retained only a slight line and were satisfied with the results. None of the patients experienced complete removal of wrinkle lines. Adverse effects included altered facial looks or appearances, mild local swelling, and ecchymosis at the injection sites. No systemic side effects were noted. Based on these results, the injection of botulinum toxin A seems to be an effective method of eliminating wrinkle lines on the upper third of the face in Korean patients, and it was a simple and effective nonsurgical procedure.

Adult↗
PubMed2000

Identification and characterization of a new member of the placental prolactin-like protein-C (PLP-C) subfamily, PLP-Cbeta.

We have isolated a complementary DNA (cDNA) clone that encodes a new member of the PRL-like protein-C (PLP-C) subfamily of the PRL gene family. The clone was amplified from a 13.5-day-old mouse conceptus cDNA library by PCR using primers based on conserved regions of PLP-C sequences. The full-length cDNA encodes a predicted protein of 241 residues, which contains a putative signal sequence and 2 putative N-linked glycosylation sites. The predicted protein shares 55-66% amino acid identity with mouse PLP-Calpha and rat PLP-D, PLP-H, PLP-Cv, and PLP-C and also contains 6 homologously positioned cysteine residues. Thus, we named this protein PLP-Cbeta for consistency. We have also isolated rat PLP-Cbeta from rat placenta cDNA library. Surprisingly, two messenger RNA (mRNA) isoforms of rat PLP-Cbeta were isolated: one mRNA (rPLP-Cbeta) encodes a 241-amino acid product, but another mRNA (rPLP-Cbetadelta39) lacks 39 bases that encode for a region rich in aromatic amino acids. The 39-bp region corresponds to exon 3 of other PLP-C subfamily members, such as PLP-Calpha, PLP-Cv, and d/tPRP. It suggests that the two isoforms are probably generated by an alternative splicing from a single gene. RT-PCR analysis revealed that the rPLP-Cbeta form was dominantly expressed in placenta, although both isoforms are coexpressed during placentation. The mouse PLP-Cbeta mRNA expression, which was specific to the placenta, was first detected by Northern analysis on embryonic day 11.5 (E 11.5) and persisted until birth. However, in situ hybridization analysis revealed mPLP-Cbeta expression on E 10.5 in specific trophoblast subsets, such as giant cells and spongiotrophoblast cells. mPLP-Cbeta mRNA was detected in the labyrinthine zone on E 18.5, suggesting that spongiotrophoblast cells had penetrated the labyrinthotrophoblast zone. Consistent with the observed expression in trophoblast giant cells, PLP-Cbeta expression was also detected in in vitro differentiated Rcho-1 cells, which express the trophoblast giant cell phenotype. In summary, overall high amino acid identity (79%), the locations of cysteine residues, and consensus sites for N-linked glycosylation between mouse and rat PLP-Cbeta clearly indicate that PLP-Cbeta is a bona fide member of the PLP-C subfamily. The conservation between mouse and rat, the presence of alternative isoforms, and the pattern of expression during gestation suggest the biological significance of PLP-Cbeta during pregnancy.

Amino Acid Sequence↗
PubMed1999

Psx homeobox gene is X-linked and specifically expressed in trophoblast cells of mouse placenta.

We previously isolated a cDNA clone for a homeobox-containing gene with its expression restricted to the extraembryonic tissues. In this study, Psx gene expression was further examined using in situ hybridization to determine the cellular distribution of Psx transcripts during embryo development. Psx expression was first detected at embryonic day 8.5 only in trophoblast giant cells and chorionic ectoderm. At E 9.5 and E 13.5, the expression was restricted to the giant cells and the labyrinthine trophoblast layer. In addition, the gene expression was detected in differentiated Rcho-1 trophoblast cells in vitro, which is typical of trophoblast giant cells in vivo, but not in proliferating Rcho-1 cells and HRP-1 cells. Interestingly, rat Psx homologue mRNA is about 200 bp shorter than mouse Psx, suggesting that there is a high degree of sequence divergence between the mouse and rat Psx homologues. The sequence divergence, perhaps as a result of rapid evolution, is further supported by the zoo blot analysis because the Psx gene was detectable only in mouse and rat but not in other vertebrate species tested. Psx is localized to the murine X chromosome. Taken together, our results suggest that Psx gene plays a unique role in the function of differentiated trophoblast cells and also serves as a useful model for studying trophoblast cell lineages and the rapid evolution of homeobox genes.

Amino Acid Sequence↗
PubMed1998

A comparative study of the surgical treatment of axillary osmidrosis by instrument, manual, and combined subcutaneous shaving procedures.

Between 1986 and 1996, 128 patients underwent surgery for axillary osmidrosis via en bloc removal of subcutaneous cellular tissue. The patients were followed for 6 months to 7 years (average follow-up, 25 months). The authors propose three categories in which they classified shaving procedures: instrumental shavings (N = 84), manual shavings (N = 96), and combined shaving procedures (N = 76). A modified Inaba's shaver was used in instrument shavings. Combined shaving is mixture of instrument and conventional manual shaving. All patients were asked to complete a questionnaire postoperatively. This follow-up demonstrated that 92.9% of patients who underwent instrument shaving, 95.8% of patients who underwent manual shaving, and 97.4% of patients who underwent combined shaving experienced no odor or occasional, very mild axillary odor postoperatively. Postoperative scar formation was either invisible or excellent in 92.9% of instrument shavings, and 92.1% of patients who underwent the combined procedure reported either a hairless axilla or a marked decrease of axillary hair. The total satisfaction rate in the combined procedure was 94.7%, which is a better result than the instrument (92.9%) and the manual (91.7%) shaving procedures. The wound complication rate per patient with the combined procedure was 13.2%. There was no scar contracture or limitation in arm abduction. The combined subcutaneous shaving procedure using the modified Inaba's shaver has the advantages of rapid and accurate shaving, low incidence of hematoma formation, enhanced wound healing, and easy postoperative care. Therefore, en bloc resection of subcutaneous cellular tissue by combined shaving is a viable option for treatment of axillary osmidrosis.

Adolescent↗
PubMed1998

Blepharoptosis repair by selective use of superiorly based muscle flaps.

Thirty-three patients with severe blepharoptosis were treated by the superiorly based orbicularis oculi muscles, interdigitated orbicularis oculi-frontalis muscle flaps, or frontalis muscle flaps. The superiorly based muscle flaps are modifications of direct transplantation of the frontalis muscle to the tarsal plate on the basis of anatomic study that the frontalis muscle and its fascia are connected with the orbicularis oculi muscle at the eyebrow region. The selection of muscle flaps is based on the extent of levator function of patients. When eyelid excursion is moderate (3 to 5 mm), the orbicularis oculi muscle flap technique was effective. For patients with weak eyelid excursion (2 to 4 mm), the interdigitated orbicularis oculi-frontalis muscle flap was the procedure of choice. For patients with minimal eyelid excursion (less than 2 mm), frontalis muscle flap technique is indicated. The majority of patients recorded as satisfactory results according to the criteria of Souther and Jordan after an average follow-up period of 18.5 months. Even though four patients showed undercorrection, there has been no complete failure or laxity of the advanced flaps in our series. The orbicularis oculi muscle technique or the interdigitated orbicularis oculi-frontalis muscle flap technique offers several advantages over the conventional frontalis muscle flap technique, such as being a simple technique with a good operative field, single incision on supratarsal fold, no depression on the forehead, no risk of neurovascular injury, and relatively easy technique with less complication. The frontalis muscle flap technique is better in patients with less than 2-mm eyelid excursion to avoid recurrence even if the superiorly based frontalis muscle flap technique has some inherent shortcomings.

Adolescent↗
PubMed1998

Use of laser Doppler flowmetry for estimation of the depth of burns.

The trend for treatment of deep second degree burns and third degree burns is toward early excision and skin grafting. The ability to predict burn depth accurately as early as possible is important for early excision and skin grafting. This study, prospectively evaluated the ability of laser Doppler flow measurements, obtained within 72 hours after burn injury, to predict the depth of burn wounds. A Periflux system 4001 laser Doppler flowmeter was used to measure the cutaneous microflow circulation of 100 selected points of burn wounds on 44 inpatients and of 1680 selected points on 120 volunteers from March of 1993 to February of 1994. The mean value of superficial second degree burns checked by laser Doppler was 194.6 perfusion units (PU). The value of deep second degree burns was 59.7 PU, and the value of third degree burns was 5.1 PU. The mean normal cutaneous blood flow of 120 volunteers (control group) was between 4 and 9 PU, except on the head, neck, hand, and foot. Blood flow of more than 100 PU correctly predicted (90.2 percent of cases) a superficial second degree burn. Blood flow between 100 and 10 PU correctly predicted (96.2 percent of cases) a deep second degree dermal burn. That of less than 10 PU correctly predicted (100 percent of cases) a third degree burn. There was also a significant correlation between initial flow measurements and the depth of burn wounds. We conclude that laser Doppler flow measurements performed early after burn injury are useful in predicting the depth of burn wounds. Laser Doppler flowmetry has the advantage of being easy to use and noninvasive and of providing immediate results for early determination of burn depth. Laser Doppler flowmetry is useful in selecting patients for early excision and grafting of burn wounds.

Adolescent↗
PubMed1998

Endoscopic application in aesthetic and reconstructive facial bone surgery.

Twenty-three cases of endoscopically assisted facial bone surgery were performed over the past 3 years. Our series is consistent with 16 cases of aesthetic contouring surgery and 12 treatments of facial bone fracture, including three cases for recontouring of frontal bone, three cases for recontouring of zygoma, endoscopically assisted correction of three zygomatic and blowout fractures, four cases for rhinoplasty and septoplasty for deviated nose, and three cases for mandible contouring surgery. To accomplish this technique, a rigid 4-mm, 30-degree down-angled endoscope was used. The frontal bone or zygomatic arch was approached endoscopically through two or three small incisions on the frontal or temporoparietal scalp. All endoscopic instruments were then manipulated through these incisions. The approach for endoscopically assisted rhinoplasty is the same as with standard rhinoplasty procedures. The approach for zygoma complex and maxillary sinus needs an intraoral incision. Recontouring of zygoma, mandible, and nasal dorsum by an air-driven burr and rasp was performed with endoscopic visual assistance. A plate and screw fixation for zygomatic arch fracture requires an additional small skin incision over the plate for the trocar method. The duration of follow-up ranged from 6 months to 30 months. The postoperative course was satisfactory with a few complications. The extra time needed for the endoscopic procedures was less than 1 hour. Endoscopically assisted facial bone surgery can be performed with adequate visualization and direct manipulation of all facial bones. Complications usually associated with extensive incisions in the bicoronal approach may be avoided. Poor visualization in the conventional approach for operation of orbit, nose, maxillae, and mandible may be avoided by use of the endoscope. This technique may prove to be ideal for aesthetic surgery for facial skeleton with smaller scar and less morbidity.

Adolescent↗