An animal model for Pierpont syndrome: a mouse bearing the Tbl1xr1Y446C/Y446C mutation.

Pierpont syndrome is a rare disorder characterized mainly by global developmental delay, unusual facial features, altered fat distribution in the limbs and hearing loss. A specific mutation (p.Tyr446Cys) in TBL1XR1, encoding a WD40 repeat-containing protein, which is a component of the SMRT/NCoR (silencing mediator retinoid and thyroid hormone receptors/nuclear receptor corepressors), has been reported as the genetic cause of Pierpont syndrome. Here, we used CRISPR-cas9 technology to generate a mutant mouse with the Y446C mutation in Tbl1xr1, which is also present in Pierpont syndrome. Several aspects of the phenotype were studied in the mutant mice: growth, body composition, hearing, motor behavior, thyroid hormone state and lipid and glucose metabolism. The mutant mice (Tbl1xr1Y446C/Y446C) displayed delayed growth, altered body composition with increased relative lean mass and impaired hearing. Expression of several genes involved in fatty acid metabolism differed in white adipose tissue, but not in liver or muscle of mutant mice compared to wild-type mice (Tbl1xr1+/+). No difference in thyroid hormone plasma concentrations was observed. Tbl1xr1Y446C/Y446C mice can be used as a model for distinct features of Pierpont syndrome, which will enable future studies on the pathogenic mechanisms underlying the various phenotypic characteristics.

Multi-Parametric MRI-Based Radiomics Models for Predicting Molecular Subtype and Androgen Receptor Expression in Breast Cancer.

OBJECTIVE: To investigate whether radiomics features extracted from multi-parametric MRI combining machine learning approach can predict molecular subtype and androgen receptor (AR) expression of breast cancer in a non-invasive way. MATERIALS AND METHODS: Patients diagnosed with clinical T2-4 stage breast cancer from March 2016 to July 2020 were retrospectively enrolled. The molecular subtypes and AR expression in pre-treatment biopsy specimens were assessed. A total of 4,198 radiomics features were extracted from the pre-biopsy multi-parametric MRI (including dynamic contrast-enhancement T1-weighted images, fat-suppressed T2-weighted images, and apparent diffusion coefficient map) of each patient. We applied several feature selection strategies including the least absolute shrinkage and selection operator (LASSO), and recursive feature elimination (RFE), the maximum relevance minimum redundancy (mRMR), Boruta and Pearson correlation analysis, to select the most optimal features. We then built 120 diagnostic models using distinct classification algorithms and feature sets divided by MRI sequences and selection strategies to predict molecular subtype and AR expression of breast cancer in the testing dataset of leave-one-out cross-validation (LOOCV). The performances of binary classification models were assessed via the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). And the performances of multiclass classification models were assessed via AUC, overall accuracy, precision, recall rate, and F1-score. RESULTS: A total of 162 patients (mean age, 46.91 ± 10.08 years) were enrolled in this study; 30 were low-AR expression and 132 were high-AR expression. HR+/HER2- cancers were diagnosed in 56 cases (34.6%), HER2+ cancers in 81 cases (50.0%), and TNBC in 25 patients (15.4%). There was no significant difference in clinicopathologic characteristics between low-AR and high-AR groups (P > 0.05), except the menopausal status, ER, PR, HER2, and Ki-67 index (P = 0.043, <0.001, <0.001, 0.015, and 0.006, respectively). No significant difference in clinicopathologic characteristics was observed among three molecular subtypes except the AR status and Ki-67 (P = <0.001 and 0.012, respectively). The Multilayer Perceptron (MLP) showed the best performance in discriminating AR expression, with an AUC of 0.907 and an accuracy of 85.8% in the testing dataset. The highest performances were obtained for discriminating TNBC vs. non-TNBC (AUC: 0.965, accuracy: 92.6%), HER2+ vs. HER2- (AUC: 0.840, accuracy: 79.0%), and HR+/HER2- vs. others (AUC: 0.860, accuracy: 82.1%) using MLP as well. The micro-AUC of MLP multiclass classification model was 0.896, and the overall accuracy was 0.735. CONCLUSIONS: Multi-parametric MRI-based radiomics combining with machine learning approaches provide a promising method to predict the molecular subtype and AR expression of breast cancer non-invasively.

Identification and Application of an Aptamer Targeting Papillary Thyroid Carcinoma Using Tissue-SELEX.

Aptamers, short DNA or RNA oligonucleotides, which evolved from systematic evolution of ligands by exponential enrichment (SELEX), can perform specific target recognition. Papillary thyroid carcinoma (PTC) is of high incidence worldwide, and the prognosis of advanced PTC is poor. Up to now, there is no specific biomarker that can identify PTC and defects still remain in existing diagnostic methods. Here we report an aptamer, termed TC-6, which is generated from tissue-SELEX by using sections of papillary thyroid carcinoma and a normal thyroid gland. TC-6 could specifically target intracellular components of papillary thyroid cells with high affinity ( Kd = 57.66 ± 5.93 nmol/L) and have performed excellent biocompatibility both in vivo and in vitro. Moreover, fluorescence imaging of PTC tumor-bearing mice revealed that TC-6 was able to accumulate in tumor sites and could distinguish thyroid carcinoma from other benign thyroid diseases efficiently. In addition, TC-6d, a truncated aptamer of TC-6, maintained its affinity toward PTC with Kd of 39.20 ± 8.20 nmol/L. Overall, these results indicate that TC-6 is a potential candidate for developing novel tools for diagnosis and targeted therapy of PTC.

The use of fabricated chimeric flap for reconstruction of extensive foot defects.

Repair of extensive foot defects requires both adequate tissues for wound coverage and special tissues for functional reconstruction. To maximize its function reconstruction, fabricated chimeric flaps consisting of multiple separate flaps were designed to reconstruct such defects. Five patients suffered extensive foot defects with sizes ranging from 23 × 12 cm to 38 × 14 cm(2) in multiple regions including heel, forefoot, dorsum, ankle, anterior leg, and even toes. Causes included crushing injuries, avulsion injuries, and scar excision. Most areas of the defects except heel were first covered by latissimus dorsi muscle flap or anterolateral thigh flap and their pedicles were anastomosed with recipient vessels. Then free medial plantar flaps were transferred for heel reconstruction and their pedicles were further attached to either side branches of the main source vessel or to its distal continuation. All chimeric flaps survived uneventfully and all patients were able to walk in normal footwear during the 1.5- to 4-years follow-up. None of the flaps developed ulcer and flap breakdown. The assessment by Maryland Foot Score showed that four of the five patients gained a "good" recovery and one patient showed moderate improvement of foot functions. Appearances of reconstructed heels were near-normal. The results indicate that fabricated chimeric flap has good design flexibility and may provide an option for functional reconstruction of extensive foot defects. © 2015 Wiley Periodicals, Inc. Microsurgery 36:303-309, 2016.

Treatment of severe hemifacial atrophy with dorsal thoracic adipofascial free flap and concurrent lipoinjection.

BACKGROUND: Parry-Romberg syndrome is an infrequent, acquired disorder characterized by progressive facial atrophy of the skin and soft tissue of the face and, in some cases, results in atrophy of muscles, cartilage, and the underlying bony structures. We investigated dorsal thoracic adipofascial free flap and concurrent lipoinjection as a reconstructive option for Parry-Romberg syndrome. METHODS: Thirteen patients with hemifacial atrophy caused by Parry-Romberg syndrome underwent surgical correction after their deformitiesreached a stable stage. All patients were classified as having severe atrophy; they had either atrophy of the skin and subcutaneous tissues observable in all 3 sensory branches of the trigeminal nerve or bone involvement. In all cases, we applied dorsal thoracic adipofascial free flap and concurrent lipoinjection followed by secondary revision with debulking or lipoinjection. RESULTS: The adipofascial flaps survived after the initial operation in all 13 patients. After the second-stage operation, 11 of 13 patients had achieved a natural appearance without any sagging or insufficient filling in the upper face. CONCLUSIONS: For patients with severe hemifacial atrophy with little or no bone involvement, dorsal thoracic adipofascial free flap and concurrent lipoinjection was a feasible and reliable reconstructive option.

Neck burn reconstruction with pre-expanded scapular free flaps.

BACKGROUND: The reconstruction of neck contracture deformities after severe burns is challenging. This is due to insufficient tissue to resurface the large defect after local flap transfer as well as the poor functional and cosmetic results after traditional methods such as skin grafting. We employed free transfer of pre-expanded scapular flaps to reconstruct postburn neck deformities. METHODS: In the first stage, skin expansion was performed with tissue expanders ranging from 400 to 800 mL according to the neck defect size and expanders were filled to their end volumes. In the second stage, the contracture in the neck was released and the unstable scar was resected. The pre-expanded scapular flap was then harvested and transferred to the neck defect. Flap revisions were performed 3-12 months after flap transfer. RESULTS: A total of 12 flaps (100%) were successful. The contour, colour, and texture of flaps matched well to the nearby skin. The range of motion of the neck was significantly improved. The donor defects were closed directly except for one case, which required skin grafting. CONCLUSIONS: The free tissue transfer of pre-expanded scapular flap is a valuable tool in neck burn reconstruction. It can be used safely and effectively with minimal morbidity in selected patients.

[The effect of bFGF and sucralfate on cell proliferation during continuous tissue expansion].

OBJECTIVE: To investigate the effect of local application of bFGF combined with sucralfate on the cell proliferation during continuous tissue expansion (CTE). METHODS: Nine white pigs were selected to undergo the continuous tissue expansion in this study and treated with bFGF and sucralfate, respectively as the following groups: group 1 with both bFGF and sucralfate, group 2 only with bFGF, group 3 with only sucralfate, and group 4 with saline as control. Fifteen samples were taken in each pig for immunohistochemistry analysis 1-14 days and 6 weeks after the operation. RESULTS: In the group with both bFGF and sucralfate, the epidermic basal cells proliferated significantly after the operation and reached top level in 3 days, which was statistical higher than the control group, but the multiplication of basal cell was the lowest 14 days after the operation, still more than the control group. In dermal layer, proliferation of fibroblasts, vessel endothelial cells, hair follicles epidermic cells and sweat gland epicytes was also significant higher in the group with both bFGF and sucralfate than that the control group and reached top level 7 day after the operation, but the proliferation of cells decreased obviously 14 days after the operation, still higher than the control group. The mitotic activity of cells returned to the basal level in 42 days. There were no significant differences among the group 2, group 3 and group 4. CONCLUSION: Local application of both bFGF and sucralfate could be more effect to induce cells multiplication during early skin expansion to facilitate the growth of neoformed skin soft tissue.

[Local application of bFGF and sucralfate during continuous tissue expansion].

OBJECTIVE: To investigate the effect of local application of bFGF and sucralfate during continuous tissue expansion (CTE). METHODS: CTE combined with local administration of bFGF and sucralfate was used in twelve patients with scar and nasal tip defects. Twenty three expanders were placed in the subcutaneous pockets through intralesion short incisions. Continuous expansion began at 1-3 days after expander implantation. The histomorphological changes and epidermal cell proliferation were observed. The clinical results were investigated. RESULTS: The average inflation time was 8.9 days. The average interval of the two operations was 13.5 days. The average hospitalization was 28.4 days. The average immediate stretch-back rate of the expanded skin was 25.7%. The clinical results were satisfactory without any complications. Histological examinations showed that the epidermal, granular and spinous layer became thicker. The basal cells increased significantly. The dermis thinned slightly and the collagen fibers became thicker. The elastic fiber regenerated significantly. Fibroblast and capillary density increased obviously. The immunohistochemistry analysis showed that the proliferation of epidemic basal cells was significant postoperatively. CONCLUSION: Local application of exogenous bFGF and sucralfate during CTE was feasible in patients. It could accelerate tissue expansion and improve the quality of expanded skin flap.

[Effect of local application of basic fibroblast growth factor and sucralfate on skin tissue structure after expansion].

OBJECTIVE: To investigate the effect of local application of basic fibroblast growth factor (bFGF) and sucralfate on the skin tissue structure after expansion. METHODS: Continuous tissue expansion (CTE) experimental animal model was made with constant pressure pump in nine white pigs. The bFGF and sucralfate were perfused between tissue and tissue expander. Both bFGF and sucralfate were injected in group I, both bFGF and normal saline in group II, only sucralfate in group III, and normal saline in group IV as control group. The samples were took from each pig for histomorphological assessment on the 3rd day and 6th week after expansion. RESULTS: Compared with control group, epidermal, granular spinous and basal cell thickness increased significantly (P < 0.05) in group I; in dermal layer, dermal thickened slightly and the collagen fibers became thicker and orderly; the elastic fiber regenerated significantly; the density of fibroblasts and capillaries significantly increased (P < 0.05) in group I. The collagen fibers were broken on the 3rd day and 6th week after expansion in control group. However, the thickness of the fibrous capsule layer was similar in each group. CONCLUSION: Local application of exogenous bFGF and sucralfate combined with CTE can greatly promote the skin growth. It can accelerate the tissue expansion.