Haidong Li

Lack of BRAFV600E Mutations in Giant Congenital Melanocytic Nevi in a Chinese Population

Giant congenital melanocytic nevi (CMNs) are at an increased risk for malignant transformation. To explore the mutation frequencies of BRAFV600E (V-raf murine sarcoma virus oncogene homolog B1) and NRAS (neuroblastoma ras viral oncogene homolog) codon 61 in CMNs of Chinese, we selected 55 paraffin-embedded tissue blocks, including 37 cases of medium CMNs (1.5-20cm) and 18 cases of giant CMNs (>20 cm). Direct sequencing was performed to detect the BRAFV600E and NRAS codon 61 mutations. The BRAFV600E mutations were detected in 9 of 55 nevi (16.4%). In medium CMNs, 9 of 37 BRAFV600E mutations (24.3%) were detected. Notably, in giant CMNs, no BRAFV600E mutations were found. The difference between these frequencies is statistically significant (P = 0.0231). NRAS codon 61 mutations were detected in 13 of 55 nevi (23.6%), including 10 of 37 medium CMNs (27.0%) and 3 of 18 giant CMNs (16.7%). Additionally, the BRAFV600E and NRAS codon 61 mutations did not coexist in the same sample. Finally, we found that the NRAS codon 61 mutation was significantly related to the amount of sun exposure (0 of 18 CMNs from sites of intermittent sun exposure and 13 of 36 CMNs from sites of chronic continuous sun exposure, P = 0.0024). The paradoxically higher incidence of BRAFV600E mutations in medium-sized compared with giant CMNs suggests that the presence of the BRAFV600E mutation may play different roles between medium and giant CMNs in melanocytic tumorigenesis.

Characterization of a Self-renewing and Multi-potent Cell Population Isolated from Human Minor Salivary Glands.

Adult stem cells play an important role in maintaining tissue homeostasis. Although these cells are found in many tissues, the presence of stem cells in the human minor salivary glands is not well explored. Using the explant culture method, we isolated a population of cells with self-renewal and differentiation capacities harboring that reside in the human minor salivary glands, called human minor salivary gland mesenchymal stem cells (hMSGMSCs). These cells show embryonic stem cell and mesenchymal stem cell phenotypes. Our results demonstrate that hMSGMSCs have the potential to undergo mesodermal, ectodermal and endodermal differentiation in conditioned culture systems in vitro. Furthermore, in vivo transplantation of hMSGMSCs into SCID mice after partial hepatectomy shows that hMSGMSCs are able to survive and engraft, characterized by the survival of labeled cells and the expression of the hepatocyte markers AFP and KRT18. These data demonstrate the existence of hMSGMSCs and suggest their potential in cell therapy and regenerative medicine.

SNPs and interaction analyses of IRF6, MSX1 and PAX9 genes in patients with non‑syndromic cleft lip with or without palate

Non‑syndromic cleft lip with or without cleft palate (NSCL/P) is a common congenital deformity, often associated with missing or deformed teeth. The genes interferon regulatory factor 6 (IRF6), muscle segment homeobox 1 (MSX1) and paired box gene 9 (PAX9) are important for the development of the maxillofacial region and dentition. The aim of this study was to explore how genetic variations in IRF6, MSX1 and PAX9, as well as gene‑gene interactions, are associated with NSCL/P. We investigated 9 IRF6 tag single nucleotide polymorphisms (SNPs), 2 MSX1 tag SNPs and 8 PAX9 tag SNPs selected from HapMap data from the Chinese population. The SNPs were examined for associations with NSCL/P in 204 patients and 226 controls. The results demonstrated a significant association between NSCL/P and rs2073485, rs2235371, rs2236909 and rs861020 in the IRF6 gene, and haplotype analysis supported these findings. A marginally significant difference was observed in the NSCL/P group for rs17176643 in the PAX9 gene compared to the control group. The results of gene‑gene interaction analyses also indicated that the combination of rs2073485, rs2235371 or rs2236909 in IRF6 and rs17176643 in PAX9, increased the risk of NSCL/P. Thus, our study provided additional understanding of IRF6 variations in patients with NSCL/P and suggested that interactions between the IRF6 and PAX9 genes are potentially important for susceptibility to NSCL/P.

An innovative cross-lip flap with a musculomucosal pedicle based on the vascular network of the lower lip.

Summary: The Abbe flap has been used for full-thickness defects of the upper lip with the inferior labial artery as the pedicle. Using the fine artery anatomy of the lower lip, the authors developed an innovative partial-thickness myocutaneous flap based on the vascular network of the submucosal and subcutaneous layers, which derived mainly from the horizontal labiomental artery or the vertical labiomental artery. From 2010 to 2011, this new technique was used in 33 patients with upper lip defects. The split flap was elevated from the posterior portion of the oris orbicularis muscle after the inferior labial artery was divided. All 33 cases of musculomucosal pedicle flaps were viable. The flap was perfectly symmetrical after the first-stage operation, and the operative time was reduced significantly.

Lack of Association Between MTHFR, MTR, MTRR, and TCN2 Genes and Nonsyndromic CL±P in a Chinese Population: Case-Control Study and Meta-Analysis.

Nonsyndromic cleft lip with or without cleft palate (NSCLP) is a common congenital deformity, often associated with folate deficiency. The genes MTHFR, MTR, MTRR, and TCN2 play key roles in folate metabolism. The risk of NSCLP associated with particular variants in the folic acid pathway differs among ethnic groups. The goal of this study was to explore whether genetic variations in these four genes, as well as gene-gene interactions, are associated with NSCLP. We investigated 7 tagSNPs for MTHFR, 18 tagSNPs for MTR, 15 tagSNPs for MTRR, and 7 tagSNPs for TCN2 selected from HapMap data in a Chinese population. These single nucleotide polymorphisms (SNPs) were examined for associations with NSCLP in 204 patients and 226 controls. We then performed a meta-analysis of association between rs1801133 and NSCLP. There was a significant difference in the allele frequency and haplotype analysis of rs4077829 and rs10802565 in MTR between the NSCLP and control groups but not a significant difference after correction with 10,000 times permutations. The allele frequency, haplotype analysis, and gene-gene interactions of other SNPs did not show a significant difference. The meta-analysis results showed that no significant differences were found for allele comparison, heterozygote comparison, homozygote comparison, dominant model comparison, or recessive model comparison. The alterations of folate metabolism related to these polymorphisms are not involved in NSCLP in the Chinese population.

Trans-Sutural Distraction Osteogenesis for Midfacial Hypoplasia in Growing Patients with Cleft Lip and Palate: Clinical Outcomes and Analysis of Skeletal Changes.

Background: Although maxillary distraction osteogenesis has been used for early treatment of midfacial hypoplasia, the inevitable osteotomies are still a complicated and invasive procedure for growing patients. Based on the bone-borne trans-sutural distraction osteogenesis, novel improvements to the approach were made to treat midfacial hypoplasia, and the clinical outcomes and skeletal changes were analyzed. Methods: Seventy consecutive growing cleft lip and palate patients with midfacial hypoplasia were treated with trans-sutural distraction osteogenesis. The distraction system consists of a rigid external distractor, nickel-titanium shape memory alloy spring, and bone-borne traction hooks. The whole distraction process was recorded in detail clinically. Lateral cephalographs and computed tomographic scans were taken and analyzed by cephalometric measurement and color-map analysis to assess the skeletal changes. Results: All of the patients except one achieved satisfactory appearance and occlusal relationship. The unilateral maximum traction force presented an increased trend with age, but this relationship was not absolute. The whole trans-sutural distraction osteogenesis process was divided into three clinical stages: the startup period, the rapid movement period, and the consolidation period. Cephalometric analysis showed a great increase in SNA, ANB and horizontal movement of the maxillae after distraction, but with marginal relapse at 6 to 18 months postoperatively. Visualized changes of the midfacial skeleton were observed by three-dimensional color mapping. The results showed an unequal advancement in different regions. Conclusion: Trans-sutural distraction osteogenesis process with adaptations offers an alternative method for the early treatment of midfacial hypoplasia in growing patients with cleft lip and palate. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Maternal transmission effect of a PDGF-C SNP on nonsyndromic cleft lip with or without palate from a Chinese population.

Cleft lip with or without palate (CL/P) is a common congenital anomaly with a high birth prevalence in China. Based on a previous linkage signal of nonsyndromic CL/P (NSCL/P) on the chromosomal region 4q31–q32 from the Chinese populations, we screened the 4q31–q32 region for susceptibility genes in 214 trios of Han Chinese. PDGF-C, an important developmental factor, resides in the region and has been implicated in NSCL/P. However, in our family-based association test (transmission disequilibrium test; TDT), we could not conclude an association between PDGF-C and NSCL/P as previously suggested. Instead, we found strong evidence for parent-of-origin effect at a PDGF-C SNP, rs17035464, by a likelihood ratio test (unadjusted p-value = 0.0018; Im = 2.46). The location of rs17035464 is 13 kb downstream of a previously reported, NSCL/P-associated SNP, rs28999109. Furthermore, a patient from our sample trios was observed with a maternal segmental uniparental isodisomy (UPD) in a region containing rs17035464. Our findings support the involvement of PDGF-C in the development of oral clefts; moreover, the UPD case report contributes to the collective knowledge of rare variants in the human genome.

Bilobed mucosal flap for correction of secondary lip deformities following cleft lip surgery

BACKGROUND Upper lip whistling deformities, asymmetric upper lip thickness and insufficient vermilion tubercle often occur simultaneously in an affected individual. Unfortunately, these deformities cannot be corrected by a single conventional method. Here, we describe a new technique, using a vermilion-bilobed flap, to address the triplex of deformities simultaneously. METHODS A total of 30 A Thirty patients were included in this study. Their ages ranged from 10 to 35 years. The flap consisted of two lobes: one lobe of the flap was located at the oral mucosa of the prolabium, which allowed for correction of the whistle deformity as well as augmentation of the vermilion tubercle; the other was located at the vermilion mucosa on the lateral side of the cleft, which effectively repaired oral mucosal defects. Quantitative measurements of the vermilion shape were performed before surgery and 6 months postoperatively. RESULTS All patients healed well with no complications of the flaps.The gross appearance of the vermilion was significantly improved. Normal tubercles were restored and symmetric profiles of vermilion were achieved. All the patients were satisfied with their final appearance. CONCLUSIONS The bilobed vermilion mucosal flap is a safe technique, easy to perform and effectively corrects the combined secondary deformities associated with cleft lip surgery.

Muscle tension line concept in nasolabial muscle complex--based on 3-dimensional reconstruction of nasolabial muscle fibers.

BackgroundPlastic surgeons have attempted various ways to rebuild the aesthetic subunits of the upper lip in patients with cleft lip with less than perfect results in most cases. We propose that repairing the 3 muscle tension line groups in the nasolabial complex will have improved aesthetic results. MethodsMicro–computed tomographic scans were performed on the nasolabial tissues of 5 normal aborted fetuses and used to construct a 3-dimensional model to study the nasolabial muscle complex structure. ResultsThe micro–computed tomographic (CT) scans showed the close relationship and interaction between the muscle fibers of nasalis, pars peripheralis, levator labii superioris, and pars marginalis. ConclusionsBased on the 2-dimensional images obtained from the micro–computed tomographic scans, we suggest the concept of nasolabial muscle complex and muscle tension line group theory: there is a close relationship among the alar part of the nasalis, depressor septi muscle, orbicularis oris muscle, and levator labii superioris alaeque nasi. The tension line groups are 3 tension line structures in the nasolabial muscle complex that interlock with each other at the intersections and maintain the specific shape and aesthetics of the lip and nose.

Aesthetic reconstruction of the upper lip with novel split musculomucosal-pedicle cross-lip flap.

BackgroundThe upper lip can be divided into aesthetic subunits. Accordingly, we classified the upper lip defect into 3 categories: medial subunit defect, lateral subunit defect, and cross-subunit defect. The defect should be repaired aesthetically. We developed an innovative partial-thickness myocutaneous flap based on the vascular network of the submucosal and subcutaneous layers. The flap was more flexible for aesthetic reconstruction of the upper lip, even the fine anatomic structures. MethodsFor three and a half years, a total of 59 patients were used with this new technique, including those with secondary deformities from bilateral cleft lip, postinjury upper lip defects, and posthemangioma treatment defects. The inclusion criteria were that the defects of the upper lip were within 2.0 cm in adults and 1.5 cm in children generally. The split flap was elevated from the posterior portion of the orbicularis oris muscle after the inferior labial artery was divided. The flap was supplied by the vascular network derived mainly from the horizontal labiomental artery and/or the vertical labiomental artery. ResultsAll 59 cases of musculomucosal-pedicle flaps were viable. The upper lip was reconstructed according to the aesthetic subunits. In some cases, the fine anatomic structures were reconstructed, including the philtral column, the philtral dimple, curve of the Cupid’s bow, and vermilion tubercle. The patients were all satisfied with their appearance. ConclusionsThis myocutaneous cross-lip flap with musculomucosal-pedicle is an effective method for aesthetic reconstruction of the upper lip. It can provide larger tissue with better flexibility and plasticity in clinical application.