Two-stage orthogonality based estimation for semiparametric varying-coefficient models and its applications in analyzing AIDS data.

Semiparametric smoothing methods are usually used to model longitudinal data, and the interest is to improve efficiency for regression coefficients. This paper is concerned with the estimation in semiparametric varying-coefficient models (SVCMs) for longitudinal data. By the orthogonal projection method, local linear technique, quasi-score estimation, and quasi-maximum likelihood estimation, we propose a two-stage orthogonality-based method to estimate parameter vector, coefficient function vector, and covariance function. The developed procedures can be implemented separately and the resulting estimators do not affect each other. Under some mild conditions, asymptotic properties of the resulting estimators are established explicitly. In particular, the asymptotic behavior of the estimator of coefficient function vector at the boundaries is examined. Further, the finite sample performance of the proposed procedures is assessed by Monte Carlo simulation experiments. Finally, the proposed methodology is illustrated with an analysis of an acquired immune deficiency syndrome (AIDS) dataset.

[Effect of vacuum drainage on the blood circulation of expanded flap in ear reconstruction].

OBJECTIVE: To investigate the effect of vacuum drainage on blood circulation of expanded skin flap, so as to confirm suitable negative pressure for ear reconstruction. METHODS: 21 patients (Auricular Reconstructive Center of Plastic Surgery Hospital, PUMC) were randomly divided into A, B, C 3 groups to receive vacuum drainage of: -20, -40 and -60 kPa, respectively. The length and width of reconstructed ears,which represented the swelling degree, were measured instantly and 5, 10 days postoperatively. The changes were calculated and reflected venous drainage of flaps. The temperature of proximal (concha) and distal (helix) part of the expanded flaps, which represented the arterial blood supply of flaps, was detected by infrared thermography after operation. RESULTS: Five days after operation [(1.48 +/- 0.47) mm, (0.36 +/- 0.06) mm] and immediately [(1.67 +/- 0.69) mm, (0.40 +/- 0.16) mm)] , the changes of the length and width of reconstructed ear in group B was significantly low, while there was no statistically difference between group A and C (P > 0.05). The data between 10 days and 5 days after operation showed the same result. Along with the increase of the negative pressure, the swelling degree of reconstructed ears decreased firstly and then increased reversely ( P < 0.01 ). The flap temperature of reconstructed ears increased (P < 0.01), especially in proximal (concha) part (P < 0.01) , when the negative pressure increased (0 to -60 kPa). CONCLUSIONS: Vacuum drainage has effect on both the venous drainage and blood supply. Negative pressure of -40 kPa can improve both the blood supply and venous drainage. It should be as reference for clinical application.

[Ear reconstruction after rupture of postauricular expanded flap].

OBJECTIVE: To summarize the principles of ear reconstruction after rupture of postauricular expanded flap. METHODS: The rupture of the postauricular expanded flap was graded as I-IV degree. For flap rupture of I and II degree, the ear reconstruction was performed immediately with autogenous cartilage framework. For flap rupture of III degree, topical and systemic treatment should be done to relieve the redness and swelling. Then the ear reconstruction was performed. For flap rupture of IV degree, the expanded postauricular flap was smoothened. Ear reconstruction was performed 3 months later. RESULTS: There were 67 cases with flap rupture, including 43 cases as I and II degree, 17 cases as III degree and 7 cases as IV degree. Ear reconstruction with autogenous cartilage framework was performed in 43 cases, with Medpor framework in 17 cases. Flap smoothing and secondary ear reconstruction with autogenous cartilage framework was performed in 7 cases. The results were satisfactory with complications in 4 cases (7%), which resolved after treatment. Primary healing was achieved in all the patients. CONCLUSIONS: Good result could be achieved in ear reconstruction, even after flap rupture. Proper treatment should be adopted according to the rupture degree.

[Application of bi-pedicled frontal expanded flap for cervical cicatricial contracture].

OBJECTIVE: To investigate the therapeutic effect of bi-pedicled frontal expanded flap for cervical cicatricial contracture. METHODS: Tissue expanders were implanted under frontal muscle. After expansion, the frontal flaps were designed based on bilateral superficial temporal vessels and were transferred to the neck wound. The cervical spine movement and the mento-cervical angle was measured and analyzed by SPSS16.0 and t test. RESULTS: From September 2006 to May 2010, 7 patients were treated by this method. The range of active cervical movement was improved in all direction. The mento-cervical angle decreased from (152.7 +/- 1.9) to (90.7 +/- 2.2) degrees after operation. The patients were followed up for 5 months to 3 years with satisfactory result and no contracture recurrence. CONCLUSIONS: The bi-pedicled expanded frontal flap has a reliable blood supply and is very suitable for cervical cicatricial contracture with good functional and esthetic results, leaving less morbidity at donor site.

[Fabrication and application of three-dimensional autogenous cartilage framework in auricular reconstruction].

OBJECTIVE: To explore the fabrication and application of three-dimensional autogenous cartilage framework in auricular reconstruction. METHODS: The process of fabrication of three-dimensional cartilage framework consisted of cartilage harvesting, carving and assembling the cartilage. The rib cartilage was harvested separately. The three-dimensional framework was composed of three main parts:the helix, the base and the pad, at different layer. The framework was fabricated according to the development of rib cartilage and contour and height of the reconstructed ear. RESULTS: From January 1992 to December 2006, 5,248 patients of microtia were treated with 6,252 autogenous cartilage frameworks. CONCLUSIONS: The three-dimensional framework is easily manipulated. The reconstructed ears look natural and had an erect contour. This method can effectively use the cartilage.

[Application of quantitative tissue expansion in ear reconstruction].

OBJECTIVE: To explore the application of tissue expander in ear reconstruction and to deal with the complications. METHODS: 50 ml kidney-shape tissue expanders were implanted subcutaneously in the mastoid area. The drainage tube was removed 3 days after operation. The suture was removed 10 days later. Since 7 days after operation, 5 ml NS was injected into the expander every time, three times a week. The total injection volume was about 60 ml. After that, the expander was maintained for one month. RESULTS: From January 1992 to December 2006, 5,248 patients of microtia were treated with 6,252 expander. After the maintaining period, the expanded skin was thin and well-vascularized. The complication rate was 7.79%, including hematoma, malunion and infection. CONCLUSIONS: The quantitative tissue expansion is easily manipulated with few complications. It can provide hairless, thin skin with reliable blood supply for ear reconstruction.

Comprehensive surgical approaches to management of various facial nevi.

OBJECTIVE: To investigate the effects of the flexible surgical approaches on therapeutic and cosmetic outcomes of facial nevi. METHODS: From August 2002 to January 2008, 16 cases with facial nevi had been treated in our wards with the selected approaches. Surgical approaches including serial excision or one-time radical excision, free skin graft, and expanded flap were adopted in accordance with the individual size and location of the facial nevi. RESULTS: All cases experienced complete excision and had satisfactory cosmetic appearance in the end. CONCLUSION: The flexible surgical measures help to minimize the risk of malignant transformation and achieve good cosmetic results.

[Surgical treatment and etiological analysis of polyotia].

OBJECTIVE: To explore the surgical treatment and pathologic mechanism of polyotia. METHODS: The operative methods for polyotia were flexible. The main procedures were aimed at the remodeling of tragus with the redundant tissue. Tissue transplantation was used to correct the depression deformity. Compound auricular tissue transplantation and Z-plasty were used for correction of the malformation at the posterior part of polyotia. RESULTS: From 2003 to 2008, 9 patients with polyotia were treated. The tragus was reconstructed after resection of redundant tissue. The depression deformity was corrected with tissue infilling in 6 cases. The compound auricular tissue transplantation was performed in 4 cases. Z-plasty at the lower ear lobe was performed in 2 cases. The appearance and the location of the reconstructed ears looked symmetric to the healthy ear. CONCLUSIONS: Natural and symmetric appearance of reconstructed ear can be achieved in polyotia. The abnormal migration of neural crest cell might be the pathologic mechanism of polyotia.

[Study of methylation of promoter of EYA1 gene in microtia].

OBJECTIVE: To explore the methylation of CpG islands in promoter of eye absent gene 1 (EYA1) in microtia. METHODS: The methylation of CpG islands in EYA1 gene in 64 microtias and 36 healthy controls were measured using the technique of matrix-assisted laser desorption/ionization-time of flight. RESULTS: The methylation of CpG_Unit3 and CpG_Unit5 of EYA1 gene in microtia were 0.09258 +/- 0.033846 and 0.0922 +/- 0.02379, respectively, which were significantly lower than those in control. CONCLUSIONS: Hypomethylation in microtia may be related to the pathogenesis of the disease.

[Design and application of the expanded transposition flaps in the treatment of cheek skin defects].

OBJECTIVE: To introduce the design and application of the expanded transposition skin flap in the treatment of cheek skin defects. METHODS: The expanded transposition flaps were divided into three types: the regular expanded transposition flap (ERT flap), the expanded transposition-advancement-transposition flap (TAT flap) and the expanded rotation-advancement-transposition flap (RAT flap). 135 cases of cheek skin defects resulted from hemangioma, scar and naevi were treated with these three types of flaps. Delay surgery was needed when the ratio of length to width was bigger than 2 : 1. RESULTS: There were 139 expanded transposition flaps, including 17 ERT flaps, 69 TAT flaps, 53 RAT flaps. Blood supply disturbance was happened at the end of the flaps in 6 cases, including 2 ERT flaps and 4 other flaps. Other flaps had no complication. The results were satisfactory. CONCLUSIONS: The expanded transposition skin flap is a reliable method to repair the cheek skin defect. The preoperative flap design is very important for successful reconstruction.

[Clinical application of three methods for total ear reconstruction].

OBJECTIVE: To investigate the indication and results of three methods for total ear reconstruction. METHODS: 960 cases of total ear defect were treated with skin expansion and autogenous rib cartilage framework (n = 786), or skin expansion and Medpor framework (n = 150), or ear prosthesis (n = 24). The indication and results of the three methods were analysed. RESULTS: Good cosmetic results were achieved with all three methods. Autogenous rib cartilage framework was suitable for patients under 30 years old with unaffected skin at mastoid region. Medpor framework was good for grown-up, especially over 30 years old, or with mild infection at mastoid region. Patients with severe skin injury at mastoid region or unwilling to accept surgery should choose ear prosthesis. CONCLUSIONS: Satisfactory results can be achieved with suitable methods for total ear reconstruction.

[The experimental study on the effect of CDMP-1 on proliferation of residual ear chondrocytes of microtia cultured in vitro].

OBJECTIVE: To investigate the alternation of biological characteristics of residual ear chondrocytes when proliferating in vitro, and study the effects of CDMP-1 on proliferation and differentiation of residual ear chondrocytes. METHODS: Residual ear chondrocytes were cultured in vitro. Then we observed the effect of CDMP-1 on differentiation by immunohistochemistry of collagen type II and dyeing with toluidine blue, investigated proliferation effects of CDMP-1 by method of MIT, and analysis cell cycle changes by flow cytometry. RESULTS: The quantity of GAG gradually decreased along with the increase of the doubling time of chondrocytes in vitro. The quantity of chondrocytes with positive expression of collagen type II were significantly more in the experimental group used with CDMP-1 than the contrast. And the most efficient concentration of CDMP-1 was 100 ng/ml. CONCLUSIONS: CDMP-1 had a good effect on proliferating and could maintain morphology of the residual ear chondrocytes of microtia cultured in vitro.

[Surgical treatment of acquired ear defect].

OBJECTIVE: To explore surgical procedure for the treatment of acquired ear defect. METHODS: The ear reconstruction was carried out by using soft tissue skin expander and autogenous rib cartilage framework, Medpor framework, auricular prosthesis, and so on. RESULTS: The long-term follow-ups showed that the flap of reconstructed ear was ruddy, soft, with normal sensory function. The cartilage framework had no degeneration, absorption and deformation. The Medpor framework had no deformation. The contour of auricular prosthesis was vivid and the implant system was stable. In addition, the reconstructed ears were coincidence with the normal side on location, form and dimension. CONCLUSIONS: It may be a major method for traumatic ear reconstruction that the soft tissue skin expander with autogenous rib cartilage framework could be applied at present time. In some special circumstances, the soft tissue skin expander with Medpor framework and auricular prosthesis may be other helpful choices.

[Ear reconstruction using soft tissue expander in the treatment of congenital microtia].

OBJECTIVE: To explore surgical procedure of congenital microtia. METHODS: Ear reconstruction was made using soft tissue skin expander and autogenous rib cartilage framework. RESULTS: Long time follow-up showed that the flap of reconstructed ear was ruddy, soft, with normal sensory function; cartilage framework had no degeneration, absorption and deformation. In addition, the reconstructed ears were coincidence with the normal side on location, form and dimension. CONCLUSIONS: It was a good method for congenital microtia to use soft tissue skin expander together with autogenous rib cartilage framework at present time.

[Correction of cupped ear by using a stainless steel wire suspension technique].

OBJECTIVE: To evaluate a new reliable surgical technique for correction the congenital cupped ear. METHODS: With 96 patients, a stainless steel wire was introduced to suspend auricular cartilage on the pericranium after the cupped ear was corrected. The follow-ups were carried out after the operation. RESULTS: Up to 3 years follow-ups with 52 cases, the results were satisfactory and durable. CONCLUSIONS: The above mentioned technique could be a reliable way to correct mild and moderate cupped ear abnormalities.

[Clinical study of chest development after costal cartilage harvesting in children].

OBJECTIVE: To evaluate the development of the chest wall after costal cartilage harvesting in children. METHODS: Thirty-nine patients, who underwent microtia reconstruction with costal cartilage grafts, were examined in the donor-site with physical examination and radiography. Forty normal children were selected as control. RESULTS: There were no significant differences in size between the bilateral chests, and compared to the control. The rib deformity in each donor site was not observed on the radiography. CONCLUSIONS: The costal cartilage harvesting in children has no significant evidence to influence the development of the chest wall.

[Treatment of helical keloid with retroauricular skin expansion].

OBJECTIVE: To introduce a new technique for the treatment of helical keloid. METHODS: The procedure consisted of two steps. In the first step, a kidney-shaped expander of 50 ml was placed subcutaneously in the retroauricular area. Routine inflation with normal saline followed. In the second step, about two months afterwards, the expander was taken out and the helical keloid was excised. The expanded flap was advanced to cover the wound. RESULTS: The operation has been performed on 12 patients of 16 sites of helical keloid since 2000. Postoperative follow-up from 3 months to 2 years revealed satisfactory results. The reconstructed ear maintained a good contour. CONCLUSION: The technique creates a retroauricular flap rich in blood supply, which can be used to close the defect left by helical keloid excision. It provides a good treatment for the helical keloid replaced with normal skin from the mastoid region.

[A study on the inhibiting effects of transforming growth factor-beta R II antibody on fibroblasts].

OBJECTIVE: To investigate the inhibiting action of transforming growth factor-beta type R II receptor(TGF-beta R II) antibody to fibroblasts. METHODS: Four groups of cultured skin fibroblasts were treated with different dosages of TGF-beta R II antibody. Examinations were performed with HYP, MTT, microscope, and flow cytometry techniques. RESULTS: TGF-beta R II antibody resulted in significant inhibition of fibroblasts(P < 0.01). CONCLUSION: TGF-beta R II antibody has inhibiting effects on the proliferation of skin fibroblasts and with a dose-dependent manner.