Bionic mechanical design and 3D printing of novel porous Ti6Al4V implants for biomedical applications / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

In maxillofacial surgery, there is a significant need for the design and fabrication of porous scaffolds with customizable bionic structures and mechanical properties suitable for bone tissue engineering. In this paper, we characterize the porous Ti6Al4V implant, which is one of the most promising and attractive biomedical applications due to the similarity of its modulus to human bones. We describe the mechanical properties of this implant, which we suggest is capable of providing important biological functions for bone tissue regeneration. We characterize a novel bionic design and fabrication process for porous implants. A design concept of "reducing dimensions and designing layer by layer" was used to construct layered slice and rod-connected mesh structure (LSRCMS) implants. Porous LSRCMS implants with different parameters and porosities were fabricated by selective laser melting (SLM). Printed samples were evaluated by microstructure characterization, specific mechanical properties were analyzed by mechanical tests, and finite element analysis was used to digitally calculate the stress characteristics of the LSRCMS under loading forces. Our results show that the samples fabricated by SLM had good structure printing quality with reasonable pore sizes. The porosity, pore size, and strut thickness of manufactured samples ranged from (60.95± 0.27)% to (81.23±0.32)%, (480±28) to (685±31) μm, and (263±28) to (265±28) μm, respectively. The compression results show that the Young's modulus and the yield strength ranged from (2.23±0.03) to (6.36±0.06) GPa and (21.36±0.42) to (122.85±3.85) MPa, respectively. We also show that the Young's modulus and yield strength of the LSRCMS samples can be predicted by the Gibson-Ashby model. Further, we prove the structural stability of our novel design by finite element analysis. Our results illustrate that our novel SLM-fabricated porous Ti6Al4V scaffolds based on an LSRCMS are a promising material for bone implants, and are potentially applicable to the field of bone defect repair.

Functional evaluation of a "two in one" urethroplasty for hypospadias / 中华整形外科杂志

<p><b>OBJECTIVE</b>To assess the functional result of a "Two in One" urethroplasty which combined oral mucosa graft and local flap.</p><p><b>METHODS</b>17 patients with hypospadias underwent a "Two in One" urethroplasty, which combined buccal mucosa and local flap for urethral reconstruction. Uroflowmetry was performed 1 day before and 1 year after operation. The urine flow rate, voided volume and urine flow curves were detected using a rotating sensor. The results of maximum urine flow rate (Qmax) were expressed as percentiles and compared to the Toguri value from normal children.</p><p><b>RESULTS</b>Before corrective operation, 12 of 17 patients (70.6%) produced a plateau urine flow curve. 5 patients (29.4%) produced a very low flow curve. The average maximum flow rate was (7.89 +/- 2.29) ml/s per second compared to Toguri values, 12 of 17 patients (70.6%) had a Qmax below the normal 5th percentile. After a "Two in One" urethroplasty, a hell-shaped curve was obtained in 10 patients (58.8%). The maximum flow rate was (11.30 +/- 3.01) mL/s per second. 7 of 17 patients (41.2%) had a Qmax above the normal 25th percentile, 8 patients (47.1%) had a Qmax between the normal 25th percentile and 5th percentile, only 2 patients (11.8%) had a Qmax below the 5th percentile.</p><p><b>CONCLUSIONS</b>The functional result of the "Two in One" urethroplasty is ideal. The maximum urine flow rate of the patients increases after the operation.</p>

Clinical analysis of 52 cases of adenoid cystic carcinoma in minor salivary gland / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the prognosis of adenoid cystic carcinoma (ACC) in minor salivary glands and its influencing factors.</p><p><b>METHODS</b>Clinical data of 52 patients with ACC in minor salivary glands were reviewed. The distribution of stage was as follows: stage I (6%), stage II (21%), stage III (27%) and stage IV (46%). Counting data was analyzed by χ(2) test or Fisher's exact. Survival rates were calculated by Kaplan-Merier method. Statistical significance of differences in the cumulative survival curves was evaluated using the Log-rank test. Multivariate analysis was performed by Cox proportional hazard model.</p><p><b>RESULTS</b>All patients underwent primary tumor radical resection, 39 patients (75%) received postoperative radiation. The regional recurrence rate was 37% and distant metastasis rate was 21%. The 5-, 10-year cumulative local control rate were 68% and 63% respectively. The 5-, 10-year cumulative distant control rate were 86%, 68% respectively. The 5-, 10-year tumor specific survival rates were 70% and 54% respectively. Multivariate analysis showed that T stage, lymph node metastasis and perineural invasion were relevant to the tumor specific survival of ACC in minor salivary glands.</p><p><b>CONCLUSIONS</b>Recurrence and metastasis were the main cause of treatment failure of ACC in minor salivary glands. T stage, lymph node metastasis and perineural invasion were the independent prognostic factors of ACC in minor salivary glands. Radical surgery and reasonably postoperative radiotherapy were the main treatment strategy.</p>

Expression of epidermal growth factor receptor in salivary adenoid cystic carcinoma and its role in cancer invasion / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To assess the epidermal growth factor receptor (EGFR) status in salivary adenoid cystic carcinoma and explore its role in cancer invasion.</p><p><b>METHODS</b>Fifty-four patients with pathologically confirmed salivary adenoid cystic carcinoma (SACC) were divided into invasion group and non-invasion group. The EGFR expression was determined by immunohistochemstry (SP staining). The relations between the EGFR expression and the SACC clinical pathological characteristics were analyzed.</p><p><b>RESULTS</b>EGFR were mainly expressed in the cell membrane and cytoplasm in the tissue of SACC. The positive rate of EGFR expression in the tumor tissue was 75.9% (41/54), and EGFR was over-expressed in the cytoplasm. The positive rate of EGFR expression in invasion group was higher than that in the non-invasion group (10.0%, P < 0.05). EGFR expression were related with the SACC T stages, histological types, distant metastasis, lymph node metastasis, and nerve invasion (P < 0.05).</p><p><b>CONCLUSIONS</b>A higher expression of EGFR gene in the cytoplasm may have important effect on the progression of invasive carcinoma. Further investigations are required to develop new strategy in the treatment of salivary adenoid cystic carcinoma.</p>

Prognostic analysis of 76 cases with adenoid cystic carcinoma in salivary gland / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the prognosis of adenoid cystic carcinoma (ACC) in salivary gland and its influencing factors.</p><p><b>METHODS</b>Clinical and following-up data of 76 patients with ACC in salivary glands were reviewed. Major gland tumors represented 35.5% whereas minor gland tumors comprised 64.5% of the cohort, with 8 cases (10.5%) in stage I, 23 (30.3%) in stage II, 18 (23.7%) in stage III and 27(35.5%) in stage IV. Survival rates were calculated by Kaplan-Merier method. Cumulative survival curves were evaluated using the Log-rank test. Multivariate analysis was performed by Cox proportional hazard model.</p><p><b>RESULTS</b>The regional recurrence rate was 28.9% and distant metastasis rate was 21.1%. The overall 5-year survival rate, tumor-free survival rate and tumor-related survival rate were 73.7%, 61.8% and 74.9% respectively. The overall 10-year survival rate, tumor-free survival rate and tumor-related survival rate were 48.2%, 39.8% and 56.2% respectively. Univariate survival analysis showed pathological type, clinical stage and perineural invasion were relevant to the prognosis of ACC and multivariate analysis showed they were the independent prognostic factors of ACC in salivary gland.</p><p><b>CONCLUSIONS</b>Clinical stage, pathological type and perineural invasion were the independent prognostic factors for adenoid cystic carcinoma in salivary gland. Surgery was the first choice for the treatment of adenoid cystic carcinoma in salivary gland, and postoperative radiotherapy may prolong the tumor-free survival time of patients in stage III and IV.</p>

Evolution pattern of the Runx3 gene 5'-CpG island methylation in human salivary gland adenoid cystic carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the evolution pattern of the Runx3 gene 5'-CpG island ~3478 bp region methylation in human salivary gland adenoid cystic carcinoma (SGACC).</p><p><b>METHODS</b>Quantitative MSP method was used to detect the methylation status of CpG island in various regions (No.1-10) of Runx3 promoter region, and Western blot was used for detection of the expression of Runx3 protein in 41 salivary gland SGACC samples and corresponding non-neoplastic salivary gland tissues. A Logistic model was used to analyze the risk ratio between the methylation status of CpG island in Runx3 gene and development of salivary SGACC, meanwhile, the possible association among the methylation of Runx3 gene, the clinicopathological parameters of SGACCs, and Runx3 protein expression was compared.</p><p><b>RESULTS</b>The results of qMSP showed that the hypermethylation initially occurred at the most 5' region of the Runx3 CpG island and spread to the transcription start site. The methylation rate was highest in region No. 1 and No. 2 among the successive ten regions ranging from the 5' region to the transcription start site within the Runx3 CpG island, and lowest in the transcription start site both in SGACCs and normal salivary glands. Furthermore, there was no methylation in the transcription start site in nomal salivary glands tissues. Together with the results of Logistic model analysis, those results indicate that the transcription start site within the Runx3 promoter CpG island is critical for gene silencing. Western blot results revealed that the Runx3 protein level in SGACC was significantly lower than that in normal salivary glands (P < 0.01). In combination of the results of qMSP, it is presumed that the Runx3 gene methylation is one of the reason inducing the down-regulation of Runx3 in SGACCs.</p><p><b>CONCLUSIONS</b>Methylation of the Runx3 CpG island spreads from the most 5'-region to the transcription start site in human salivary gland adenoid cystic carcinoma, and the transcription start site may be a critical region for the methylation of Runx3. The evolution pattern of Runx3 gene methylation is related to the tumorigenesis of SGACCs.</p>

Expression of the P450arom mRNA in the glandular tissue of the pubertal mammary hypertrophy / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the expression status of the P450arom mRNA in breast tissue of pubertal mammary hypertrophy and then explore the possible etiology of pubertal mammary hypertrophy.</p><p><b>METHODS</b>15 patients were selected for pubertal mammary hypertrophy group. Breast hypertrophy tissue specimens were collected from the gland excised during reduction mammaplasty. 15 patients with pathologically simple fibroadenoma were used as another control group. Patient approval of participation in this study was obtained preoperatively. The expression of P450arom mRNA was detected by RT-PCR in all the cases above.</p><p><b>RESULTS</b>There was no significant difference between the pubertal mammary hypertrophy groups and normal groups on the expression rates of P450arom mRNA. But among the positive cases, the expression of P450arom mRNA within breast tissue were 0.202 +/- 0.048 in pubertal mammary hypertrophy group; and 0.159 +/- 0.068 in normal group. There was significant difference between the pubertal mammary hypertrophy and normal groups (P < 0.05).</p><p><b>CONCLUSION</b>The expression of P450arom mRNA in pubertal mammary hypertrophy are significantly higher than in normal mammary glandular tissue. The pubertal mammary hypertrophy may be related to the expression status of P450arom mRNA within breast tissue.</p>

Repairing traumatic partial helical defect with postauricular tube flap / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the effect of postauricular tube flap for repairing traumatic partial helical defect.</p><p><b>METHODS</b>The tube flaps were designed according to the site and size of helical defects. The length of tube flaps was 1.2 - 1.5 times as the length of the defects. The length-to-width ratio of tube flap was 3 - 4:1. The procedures required three stages for completion: (1) fabrication of tube flap; (2) 2 - 3 weeks later, division of one pedicle and insetting the flap; (3) 2 - 3 weeks later, complete division of pedicle and repairing the defects.</p><p><b>RESULTS</b>From January 1998 to June 2006, 47 cases of traumatic partial helical defects were treated with postauricular tube flaps. All the tube flaps survived completely with no vascular disturbance, infection or necrosis. The patients were followed up for 2 months to five years with satisfactory results.</p><p><b>CONCLUSIONS</b>Postauricular tube flap is a reliable and simple procedure for traumatic partial helical defects with good cosmetic result and less donor site morbidity.</p>

The long-term contrastive result of neo-urethra reconstructed with different kinds of tissue / 中华整形外科杂志

<p><b>OBJECTIVE</b>To observe the long-term apparent and structural change of the neo-urethra inner wall reconstructed with different kinds of tissue. To compare the difference between normal and reconstructed urethra for urethra reconstruction with more appropriate materials.</p><p><b>METHODS</b>The neo-urethra inner wall was observed during operation, through urography and urethroscope. The tissue section of neo-urethra inner wall was observed through light microscope and electron microscope.</p><p><b>RESULTS</b>With unchanged structure, the appearance of neo-urethra reconstructed with skin or mucosa could be close to normal urethra after a long time. Neo-urethra made of buccal mucosa possesses some of the most important basic structures for normal urethral microenvironment to form. The structure of neo-urethra made of bladder could be close to normal urethra after a long time.</p><p><b>CONCLUSIONS</b>Buccal and bladder mucosa may be a better material than skin for urethra reconstruction.</p>

Reduction mammaplasty with the superomedial glandular pedicle / 中华整形外科杂志

<p><b>OBJECTIVE</b>To explore a new technique that keep function and good aesthetic shape after reduction mammaplasty.</p><p><b>METHODS</b>The superomedial glandular pedicle technique was applied with differing patterns of skin incision according to the degree of the mammary hypertrophy. The extra glandular tissue was removed from the lateral and inferior segment of the breast. The remaining superomedial glandular tissue was remodeled a conical shape. The skin incision was sutured after excision of excess skin.</p><p><b>RESULTS</b>36 cases (72 breasts) were treated with this technique. The results were satisfactory and there were no complications. The breasts maintained a lasting and aesthetically pleasing shape and the nipple-areola preserved good sensation.</p><p><b>CONCLUSIONS</b>The superomedial glandular pedicle is a safe and effective technique that can provide long-lasting outcome. The design of the procedure can be adapted to a variety of skin incision patterns and breast morphologies.</p>

An experimental study on the culture of human oral mucosa epithelium using autologous serum / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the biological properties of cultured human oral mucosa epithelium using autologous serum in order to provide a new material for tissue engineering urethra.</p><p><b>METHODS</b>The cultured oral mucosa epithelium was respectively transplanted beneath the skin, above the deep fascia and in the wound of the athymic mice. The specimens were taken at 2, 3, 4, and 6 weeks posttransplantation, and processed for (1) immunofluorescence anti-HLA staining to determine graft acceptance, and (2) anti-human IV collagen and antihuman laminin immunohistochemical staining procedures to indicate the basement membrane formation.</p><p><b>RESULTS</b>All the grafts survived and grew very well. The grafts were positive to anti-HLA. Collagen type IV and laminin were detected at the dermo-epidermal junction in all groups from day 14, and increasing in density up to day 21.</p><p><b>CONCLUSIONS</b>he cultured human oral mucosa epithelium by autologous serum could develop an excellent functional epithelium tissue, which would be used to reconstruct urethra and repair wound.</p>

Mutation analysis of SRD5A2 gene in patients with hypospadias / 中华整形外科杂志

<p><b>OBJECTIVE</b>To explore possible molecular mechanism of hypospadias and relationship of the mutation of SRD5A2 gene to hypospadias.</p><p><b>METHODS</b>96 blood samples from the patients with hypospadias were obtained and DNA was extracted from blood leukocytes. Polymerase chain reaction and direct sequencing were performed to analyze the coding regions of SRD5A2 gene.</p><p><b>RESULTS</b>8 mutations were detected from 14 cases, including 5 missense mutations, 1 synonymous mutation, 1 nonsense mutation and 1 frameshift mutation. The mutations are in 1st, 4th and 5th exon. Gln6stop, His232His, Phe234Leu and frameshift mutations are novel.</p><p><b>CONCLUSIONS</b>Exon 4 is a hot spot region of mutation within SRD5A2 gene, and about 10 percent of hypospadiac patients complicated with SRD5A2 dysfunction or deficiency.</p>

Bacteriology study of hypospadias / 中华整形外科杂志

<p><b>OBJECTIVE</b>This clinical study was to explore why the neo-urethra is liable to be infected after hypospadias operation, find the source and the common floras of infection, and accordingly, improve the peroperation procedures so as to reduce postoperative infection rate.</p><p><b>METHODS</b>The pathogenic floras were examined and analyzed by germiculture and karyotype analysis.</p><p><b>RESULTS</b>The bacteria in the neo-urethra mostly came from the orifice and the reconstruction material of the urethra. The most common floras that caused infection were gram-positive coccus. The most sensitive antibiotics for hypospadias infection were demethylvancomycin.</p><p><b>CONCLUSION</b>The postoperative infection of hypospadias is incisional, not the urinary system infection. Because the microenvironment of the neo-urethra is more suitable for infection than that of the skin or mucosa, the reconstructed urethra is likely to be infected.</p>

Rabbit urethral defect repair with freeze-dried acellular bladder submucosa / 中华整形外科杂志

<p><b>OBJECTIVE</b>To evaluate the result of urethral defect repair using freeze-dried acellular bladder submucosa.</p><p><b>METHODS</b>The freeze-dried acellular bladder submucosa was obtained from human cadaveric bladder submucosa using freeze-thawed enzymatic treatment and the freeze-drying technique. 18 male New Zealand rabbits were used in this experiment. A defect of 1.0 cm x 0.5 cm was created in the ventral urethra of the animal. The acellular matrix was grafted to the urethral defect in 14 rabbits. The other 4 animals underwent a sham operation as the controls. From postoperative one to twenty-four weeks, the animals underwent retrograde urethrography at certain intervals. The grafts of the acellular matrix were taken and prepared for histological evaluation.</p><p><b>RESULTS</b>No obvious urethral stricture was observed in the 14 matrix-grafted animals. Histological examinations of the specimens showed progressive infiltration of cells and vascular vessels. Complete epithelization was obtained at 2 weeks. The orientation of collagen fibers in the matrix-grafted area tended to be regular with time.</p><p><b>CONCLUSIONS</b>Freeze-dried acellular bladder submucosa may be a suitable material for urethral defect repair, which induces urethral mucous cells to migrate, grow and epithelialize.</p>

The inherent liability to infection of various tissue for urethra reconstruction / 中华整形外科杂志

<p><b>OBJECTIVE</b>Observing the long-term results of reconstructed urethra to reduce the postop infection rate of hypospadias. To explore the standard of selecting tissue for urethra reconstruction by comparing the different inherent liability to infection in use of different kinds of tissue for urethra reconstruction.</p><p><b>METHODS</b>Neo-urethra inner wall and normal urethra were observed through urography and urethroscope. The tissue section of neo-urethra, normal urethra and tissue for urethra reconstruction were observed through light microscope, scanning electron microscope and transmission electron microscope.</p><p><b>RESULTS</b>The structure and liability to infection of neo-urethra made of bladder mucosa, buccal mucosa or skin never changed after long time. Metaplasia never took place in neo-urethra.</p><p><b>CONCLUSIONS</b>The structure and liability to infection of neo-urethra were the same as those of the congeneric tissue. Bladder or buccal mucosa is the best tissue for urethra reconstruction considering urethra microenvironment. Neo-urethra made of skin is more liable to infection by nature. The best opportunity of hypospadias operation should be before puberty.</p>

Autologous buccal mucosal graft pre-transplantation for urethral reconstruction of complicated hypospadias / 中华整形外科杂志

<p><b>OBJECTIVE</b>Applicate autologous buccal mucosal graft pre-transplantation for urethral reconstruction of complicated hypospadias by staging.</p><p><b>METHODS</b>From 1999 to 2003, 40 patients have been treated by method of autologous buccal mucosal graft pre-placing. There were two models: graft onlay and graft-tube for urethral reconstruction, and the 2rd operation was accomplished half year later.</p><p><b>RESULTS</b>All patients healed without urethral fistula.</p><p><b>CONCLUSION</b>The method is valuable for treatment of complicated hypospadias.</p>

Inner preputial skin grafts combined with preputial island flap for treatment of penile hypospadias / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate new methods of treatment for penile hypospadias. METHODS Urethroplasty was performed for penile hypospadias using inner preputial skin grafts combined with preputial island flap.</p><p><b>RESULTS</b>A total of 10 patients have received this procedure. After a mean follow up of one year, no fistula or urethral stricture was found. All patients obtained excellent cosmetic results.</p><p><b>CONCLUSIONS</b>This method allows for adequate correction of severe chordee. It is a useful procedure for selected cases of primary hypospadias with severe incurvation.</p>

Study of genic mutations of androgen receptor in hypospadias / 中华整形外科杂志

<p><b>OBJECTIVE</b>To study genic mutation of androgen receptor in hypospadias in Chinese.</p><p><b>METHODS</b>Ninety-two patients with hypospadias were selected for the AR gene study (penile 33, scrotal 49, perineal 10; cryptorchidism 15, micropenis 34, indirect hernia 3, augmentation of breast 2, other deformities 8; posses family history 23) while 93 health men as the control. The DNA was collected from 5 ml venous blood by using the method of phenol/chloroform, and quantified with the agarose gel electrophoresis. The 2-8 exons of AR genes were directly sequenced with a PCR technique. The locus of mutation,the change of amino acid caused by genic mutation and the functional influence of target organ were also analyzed.</p><p><b>RESULTS</b>There were 4 mutations found from the ligand binding domain of AR: exon 4[1 locus:664(ATT-->ACT] and exon 7[3 locuses: 840(CGT-->CAT),855(CGC-->CAC),859(CTC-->CTA)] in experimental group. The amino acid change of Iso664Thr may te the first findings in the world. The mutation of 859(CTC-->CTA) didn't cause the change of the code amino acid. The main clinical symptoms of exon 4[664(ATT-->ACT) were micropenis, slight hypospadias and augmentation of breasts. The exon 7[840(CGT-->CAT), 855(CGC-->CAC)]was showing micropenis and severe hypospadias. The last mutation [859(CTC-->CTA)] of exon 7 showed mild hypospadias.</p><p><b>CONCLUSIONS</b>The rate of exon 2-7 mutations of the androgen receptor was 4.3%. The mutations were concentrated on ligand binding domain(exon 4-7), and the main phenotypes were hypospadias accompanying with micropenis found in our experimental group.</p>

Clinical applications of the buried-guided-suture method in the treatment of facial depression / 中华整形外科杂志

<p><b>OBJECTIVE</b>To develop a method for the treatment of facial depression without incision scar.</p><p><b>METHODS</b>In repairing the facial depression, the ruptured subdermal adipocellular tissue was approximated and reunite with the buried-guided-suture method through an intraoral or a concealed skin incision.</p><p><b>RESULTS</b>17 patients with facial depressions from trauma were treated. Postoperative follow-up of 10 patients for one year showed satisfactory results without recurrence.</p><p><b>CONCLUSION</b>The buried-guided-suture method for repair of facial depression from trauma is simple, reliable and worth recommendation.</p>

Oral mucosa graft combined with a local turn-over flap for urethral reconstruction in various hypospadias / 中华整形外科杂志

<p><b>OBJECTIVE</b>Explore a good method for treating various hypospadias.</p><p><b>METHODS</b>Oral mucosa graft combined with a local turn-over flap was used for urethral reconstruction in 39 cases of hypospadias.</p><p><b>RESULTS</b>All the 39 cases were cured successfully in one stage, and satisfactory penile configuration obtained.</p><p><b>CONCLUSION</b>This operation solved the problem of tissue scarcity in urethral reconstruction. It made use of the merits of different materials and avoided the disadvantage of a single tissue. It is good for treating various hypospadias and worthy of popularization.</p>