The Making of a Flight Feather: Bio-architectural Principles and Adaptation.

The evolution of flight in feathered dinosaurs and early birds over millions of years required flight feathers whose architecture features hierarchical branches. While barb-based feather forms were investigated, feather shafts and vanes are understudied. Here, we take a multi-disciplinary approach to study their molecular control and bio-architectural organizations. In rachidial ridges, epidermal progenitors generate cortex and medullary keratinocytes, guided by Bmp and transforming growth factor ß (TGF-ß) signaling that convert rachides into adaptable bilayer composite beams. In barb ridges, epidermal progenitors generate cylindrical, plate-, or hooklet-shaped barbule cells that form fluffy branches or pennaceous vanes, mediated by asymmetric cell junction and keratin expression. Transcriptome analyses and functional studies show anterior-posterior Wnt2b signaling within the dermal papilla controls barbule cell fates with spatiotemporal collinearity. Quantitative bio-physical analyses of feathers from birds with different flight characteristics and feathers in Burmese amber reveal how multi-dimensional functionality can be achieved and may inspire future composite material designs. VIDEO ABSTRACT.

Combined double vascularized lymph node transfers and modified radical reduction with preservation of perforators for advanced stages of lymphedema.

BACKGROUND: Treatment of advanced lymphedema requires not only restoration of physiological lymph drainage, but also excision of fibrotic tissue and excess skin. The aim of this study is to show how the combination of double vascularized lymph node transfers (VLNTs) and a modified radical reduction with preservation of perforators (RRPP) can accomplish both of these treatment goals. METHODS: Between 2010 and 2016, 16 patients (15 female and one male) with extremity lymphedema underwent a combined double gastroepiploic VLNTs and modified RRPP. Demographics, outcomes including circumference reduction rates, preoperative and postoperative lymphoscintigraphy, complications, and responses to the Lymphedema Quality of Life (LYMQOL) questionnaire were analyzed. RESULTS: All flaps survived. The mean follow-up period was 14.2 months (range, 12-19). The mean circumference reduction rate was 74.5% ± 6.9% for the upper limb and 68.0% ± 4.2% for the lower limb. There were no major complications. Minor complications, including numbness and hyperesthesia, were treated conservatively. LYMQOL showed a 2.7-fold quality-of-life improvement (P < 0.01). Postoperative lymphoscintigraphy showed improved lymphatic drainage in all cases. CONCLUSION: Combined double VLNTs and modified RRPP safely and effectively improves lymphatic drainage, reduces fibrotic tissue and excess skin, decreases episodes of infections, and improves patients' quality of life in the advanced stages of lymphedema.

Comprehensive multimodal surgical treatment of end-stage lower extremity lymphedema with toe management: The combined Charles,' Homan's, and vascularized lymph node transfer (CHAHOVA) procedures.

BACKGROUND: End-stage lower extremity lymphedema (LEL) poses a particularly formidable challenge to surgeons as multiple pathological processes are at work. Because single modality treatment is often unsuccessful, we devised a comprehensive multimodal surgical treatment. The aim of this study is to share the technical considerations and examine the clinical outcomes of this combined approach. METHODS: Between 2013 and 2017, patients with International Society of Lymphology stage III, who underwent the combination treatment of Charles,' Homan's procedure with toe management and vascularized lymph node transfer (CHAHOVA), were included in this retrospective study. Outcomes evaluated were limb size, number of infectious episodes, compression garment usage, and rate of complications. RESULTS: A total of 68 patients were included. With a mean follow-up of 29 months, the overall circumference reduction rate for the upper thigh and the rest of the extremity was 67.4% (48.2-88.2%) and 98.1% (88-100%), respectively. During the follow-ups, 2 (2.9%) patients experienced episodes of cellulitis and the average number of yearly infections decreased from 4.2 to 1.2 episodes per person. All patients were able to discontinue compression therapy without recurrence of lymphedema. Nine (13.2%) patients reported minor complications. CONCLUSION: The combine CHAHOVA in a single-stage procedure is an effective and safe approach in the end-stage LEL.

Ileocecal vascularized lymph node transfer for the treatment of extremity lymphedema: A case report.

Vascularized lymph node (VLN) transfer has been of high interest in the past decade for the treatment of lymphedema, since it has been shown to be effective in reducing limb volumes, decreasing infectious episodes and improving quality of life. Multiple donor sites have been described in the quest for the optimal one. Herein, we describe a novel lymph node flap option based on the ileocolic artery and vein. The ileocecal vascularized lymph node (IC-VLN) flap was used in the management of a 33-year-old male patient with lower extremity lymphedema secondary to left inguinal trauma. The patient had previously underwent a pedicled omentum flap transposition with minimal improvement in limb size and persistent episodes of infection. At 15 month follow-up, the IC-VLN flap improved the lymphatic drainage in the affected limb with a mean limb circumference reduction rate of 26.3%. No donor site complications or further episodes of infection were noted. According to our findings, the IC-VLN flap may be another option for VLN transfer in very selected cases. Nevertheless, larger series with a longer follow-up are required to analyze the efficacy and long-term results of this flap.

Vascularized appendicular lymph node transfer for treatment of extremity lymphedema: A case report.

Vascularized lymph node transfer has demonstrated promising results for the treatment of extremity lymphedema. In an attempt to find the ideal donor site, several vascularized lymph nodes have been described. Each has a common goal of decreasing morbidity and avoiding iatrogenic lymphedema while obtaining good clinical results. Herein, we present the preliminary clinical outcomes of an intra-abdominal lymph node flap option based on the appendicular artery and vein used for the treatment of extremity lymphedema. A 62 year-old woman with moderate lower extremity lymphedema, on chronic antibiotics because of recurrent infections and unsatisfactory outcomes after conservative treatment underwent a vascularized appendicular lymph node (VALN) transfer. At a follow-up of 6 months, the reduction rate of the limb circumference was 17.4%, 15.1%, 12.0% and 9% above the knee, below the knee, above the ankle and foot respectively. In addition, no further episodes of infection or other complications were reported after VALN transfer. Postoperative lymphoscintigraphy demonstrated that the VALN flap was able to improve the lymphatic drainage of the affected limb. According to our findings, the use of VALN transfer minimizes donor-site morbidity, avoids iatrogenic lymphedema and may provide a strong clearance of infection because of the strong immunologic properties of the appendiceal lymphatic tissue in selected patients. Despite these promising results, further research with larger number of patients and longer follow- up is needed.

The radial forearm free flap as a "vascular bridge" for secondary microsurgical head and neck reconstruction in a vessel-depleted neck.

BACKGROUND: In a vessel-depleted neck, distant recipient sites may be the only option for secondary free flap reconstruction. While interposition vein grafts and arteriovenous loops can bridge the gap between the recipient and donor pedicle, they are not without risks. In these scenarios, we examinate the reliablity of a radial forearm free flap (RFFF) as an alternative vascular conduit. PATIENTS AND METHODS: A retrospective review of cases between March 2005 and May 2016 was performed. Demographic data, prior surgical history, intraoperative details and outcomes were recorded. A total of ten patients, eight male and two female, with a mean age of 54.2 years (range, 39-74) were identified. The RFFF was initially anastomosed to either the thoracoacromial (n = 6) or internal mammary vessels (n = 4) and subsequently served as the recipient pedicle for the second "main" flap, an anterolateral thigh (n = 4), jejunum (n = 3) or fibula flap (n = 3). RESULTS: The average RFFF dimensions were 13.8 cm by 5.8 cm. All twenty flaps, ten RFFF and ten "main' flaps survived completely with only one case of minimal epidermal loss. One patient with esophageal reconstruction with jejunum developed a fistula that required closure with a local falp. At a mean follow-up of 18.4 months (range 8-29), the reconstructive goals had been achieved in all cases. CONCLUSIONS: The RFFF serves as a reliable "vascular bridge" that extends the reach of distant recipient sites to free flaps in secondary head and neck reconstruction.

Comparison of long-term clinical outcomes among different vascularized lymph node transfers: 6-year experience of a single center's approach to the treatment of lymphedema.

BACKGROUND: This study evaluated the long-term clinical outcomes among different vascularized lymph node transfers (VLNT) used at our institution. METHODS: Between July 2010 and July 2016, all patients with International Society of Lymphology (ISL) stages II-III who underwent VLNT were evaluated. Demographic and clinical data (limb circumference, infectious episodes, lymphoscintigraphic studies) were recorded pre-operatively. Clinical outcomes, complications, and additional excisional procedures were analyzed post-operatively. At least 2-year follow-up was required for inclusion. RESULTS: Overall, 83 patients (Stage II:47, Stage III:36) met the inclusion criterion. Mean follow-up was 32.8 months (range, 24-49). Lymph node flaps used were groin (n = 13), supraclavicular (n = 25), gastroepiploic (n = 42), ileocecal (n = 2), and appendicular (n = 1). Total mean circumference reduction rate was 29.1% (Stage II) and 17.9% (Stage III) (P < 0.05). A paired t-test showed that VLNT significantly decreased the number of infections (P < 0.05). Three patients reported no improvement of the symptoms. Major complications included one flap loss and one donor site hematoma. After the period of follow-up, 18 patients (21.7%) underwent additional excisional procedures. CONCLUSION: VLNT is a promising technique used for the treatment of lymphedema and appears to be more effective in moderate stages (Stage II). Patients with advanced stage lymphedema (Stage III) may benefit from additional excisional procedures.

A head-to-head comparison among donor site morbidity after vascularized lymph node transfer: Pearls and pitfalls of a 6-year single center experience.

Between 2010 and 2016, 110 patients with extremity lymphedema underwent vascularized lymph node (VLN) transfer: groin (G-VLN = 20), supraclavicular (SC-VLN = 54), and right gastroepiploic (RGE-VLN = 36) open and laparoscopic approach. Herein, we discuss the pearls and pitfalls for VLN harvest and compare donor site morbidity and complications. Lymphatic leakage: G-VLN (n = 1) and SC-VLN (n = 1) and one hematoma: SC-VLN were found. Laparoscopic harvest of the RGE-VLN reduces donor site morbidity. However, surgeons experience is imperative to minimize donor site morbidity and complications. J. Surg. Oncol. 2017;115:37-42. © 2016 Wiley Periodicals, Inc.

The retrograde transverse cervical artery as a recipient vessel for free tissue transfer in complex head and neck reconstruction with a vessel-depleted neck.

BACKGROUND: Reconstruction in a vessel-depleted neck is challenging. The success rates can be markedly decreased because of unavailability of suitable recipient vessels. In order to obtain a reliable flow, recipient vessels away from the zone of fibrosis, radiation, or infection need to be explored. The aim of this report is to present our experience and clinical outcomes using the retrograde flow coming from the distal transverse cervical artery (TCA) as a source for arterial inflow for complex head and neck reconstruction in patients with a vessel-depleted neck. METHODS: Between July 2010 and June 2016, nine patients with a vessel-depleted neck underwent secondary head and neck reconstruction using the retrograde TCA as recipient vessel for microanastomosis. The mean age was 49.6 years (range, 36 to 68 years). All patients had previous bilateral neck dissections and all, except one, had also received radiotherapy. Indications included neck contracture release (n = 3), oral (n = 1), mandibular (n = 3) and pharyngoesophageal (n = 2) reconstruction necessitating free anterolateral thigh (n = 3) and medial sural artery (n = 1) perforator flaps, fibula (n = 3) and ileocolon (n = 2) flaps respectively. RESULTS: There was 100% flap survival rate with no re-exploration or any partial flap loss. One case of intra-operative arterial vasospasm at the anastomotic suture line was managed intra-operatively with vein graft interposition. There were no other complications or donor site morbidity during the follow-up period. CONCLUSIONS: In a vessel-depleted neck, the reverse flow of the TCA may be a reliable option for complex secondary head and neck reconstruction in selected patients.

Double gastroepiploic vascularized lymph node tranfers to middle and distal limb for the treatment of lymphedema.

BACKGROUND: Vascularized lymph node (VLN) transfer for lymphedema treatment has shown promising results. Optimal donor and recipient sites remain a matter of debate. We describe the technique and outcomes of a laparoscopically harvested extended gastroepiploic VLN flap with two levels of inset. PATIENTS AND METHODS: Between 2014 and 2015, four-patients with upper limb breast cancer-related lymphedema and three-patients with lower limb pelvic cancer-related lymphedema who underwent VLN transfers were included. After harvest, the gastroepiploic VLN flap was divided into two halves that were separately inset at the level of elbow and wrist (upper limb) or knee and ankle (lower limb). The mean patient age was 53.1 years (range, 42-65 years). RESULTS: The average flap size after division was 6.3 cm in length (range, 5-7 cm) and 3.4 cm in width (range, 3-4 cm). The mean pedicle length was 3.2 cm (range, 2.5-4 cm). All flaps survived completely. No donor or recepient site complication was noted. At a mean follow-up of 9.7 months (range, 8-11 months), the mean circumference reduction rate was 43.7 ± 2.5% along the entire limb (P < 0.05). No episode of infection was noted postoperatively. CONCLUSIONS: Double gastroepiploic VLN transfers to middle and distal limb are a safe approach with very promising results. This technique may be used to improve clinical outcomes by enhancing the lymphatic drainage of the entire affected limb in a uniform fashion. In addition, the laparoscopic harvest can provide decreased donor site morbidity with a faster recovery.

The Drosophila GOLPH3 homolog regulates the biosynthesis of heparan sulfate proteoglycans by modulating the retrograde trafficking of exostosins.

The exostosin (EXT) genes encode glycosyltransferases required for glycosaminoglycan chain polymerization in the biosynthesis of heparan sulfate proteoglycans (HSPGs). Mutations in the tumor suppressor genes EXT1 and EXT2 disturb HSPG biosynthesis and cause multiple osteochondroma (MO). How EXT1 and EXT2 traffic within the Golgi complex is not clear. Here, we show that Rotini (Rti), the Drosophila GOLPH3, regulates the retrograde trafficking of EXTs. A reduction in Rti shifts the steady-state distribution of EXTs to the trans-Golgi. These accumulated EXTs tend to be degraded and their re-entrance towards the route for polymerizing GAG chains is disengaged. Conversely, EXTs are mislocalized towards the transitional endoplasmic reticulum/cis-Golgi when Rti is overexpressed. Both loss of function and overexpression of rti result in incomplete HSPGs and perturb Hedgehog signaling. Consistent with Drosophila, GOLPH3 modulates the dynamic retention and protein stability of EXT1/2 in mammalian species. Our data demonstrate that GOLPH3 modulates the activities of EXTs, thus implicating a putative role for GOLPH3 in the formation of MO.

Repurposing of phentolamine as a potential anticancer agent against human castration-resistant prostate cancer: A central role on microtubule stabilization and mitochondrial apoptosis pathway.

BACKGROUND: Drug repurposing of phentolamine, an α-adrenoceptor antagonist, as an anticancer agent has been studied in human castration-resistant prostate cancer (CRPC). METHODS: Cell proliferation was examined by sulforhodamine B and CFSE staining assays. Cell cycle progression and mitochondrial membrane potential (ΔΨm) were detected by flow cytometric analysis. Protein expression was detected by Western blotting. Effect on tubulin/microtubule was determined using confocal immunofluorescence microscopic examination, microtubule assembly detection, tubulin turbidity assay, and binding assay. Several assessments were used to characterize apoptotic signaling pathways and combinatory effect. RESULTS: Phentolamine induced anti-proliferative effect in PC-3 and DU-145, two CRPC cell lines, and P-glycoprotein (P-gp) overexpressing cells. This effect was not significantly reduced in paclitaxel-resistant cells. Rhodamine 123 efflux assay showed that phentolamine was not a P-gp substrate. Phentolamine induced mitotic arrest of the cell cycle and formation of hyperdiploid cells, followed by an increase of apoptosis. Mitotic arrest was confirmed by cyclin B1 up-regulation, Cdk1 activation, and a dramatic increase of mitotic protein phosphorylation. Both in vitro and cellular identification demonstrated that phentolamine, similar to paclitaxel, induced tubulin polymerization and formation of multiple nuclei. Besides, it did not compete with paclitaxel binding on tubulin. Phentolamine induced the phosphorylation and degradation of Bcl-2 and Bcl-xL, two anti-apoptotic Bcl-2 family members, and the loss of ΔΨm indicating the induction of mitochondrial damage. It ultimately induced the activation of caspase-9, -8, and -3 and apoptotic cell death. Moreover, combination treatment with phentolamine and paclitaxel caused a synergistic apoptosis. CONCLUSIONS: The data suggest that phentolamine is a potential anticancer agent. In contrast to a wide variety of microtubule disrupting agents, phentolamine induces microtubule assembly, leading to mitotic arrest of the cell cycle which "in turn" induces subsequent mitochondrial damage and activation of related apoptotic signaling pathways in CRPC cells. Furthermore, combination between phentolamine and paclitaxel induces a synergistic apoptotic cell death. Phentolamine has a simple chemical structure and is not a P-gp substrate. Optimization of phentolamine structure may also be a potential approach for further development.

Arabidopsis HIT4 encodes a novel chromocentre-localized protein involved in the heat reactivation of transcriptionally silent loci and is essential for heat tolerance in plants.

The Arabidopsis mutant heat-intolerant 4-1 (hit4-1) was isolated from an ethyl methanesulphonate-mutagenized M2 population on the basis of its inability to withstand prolonged heat stress (4 days at 37°C). Further characterization indicated that hit4-1 was impaired specifically in terms of basal but not acquired thermotolerance. Map-based cloning revealed that the HIT4 gene encoded a plant-specific protein for which the molecular function has yet to be studied. To investigate the cellular role of HIT4 and hence elucidate better its protective function in heat tolerance in plants, a GFP-HIT4 reporter construct was created for a protoplast transient expression assay. Results showed that fluorescently tagged HIT4 was localized to the chromocentre, a condensed heterochromatin domain that harbours repetitive elements for which transcription is normally suppressed by transcriptional gene silencing (TGS). DAPI-staining analysis and FISH with a probe that targeted centromeric repeats showed that heat-induced chromocentre decondensation was inhibited in nuclei of hit4-1 subjected to direct heat treatment, but not in those that were allowed to acquire thermotolerance. Moreover, heat reactivation of various TGS loci, regardless of whether they were endogenous or transgenic, or existed as a single copy or as repeats, was found to be attenuated in hit4-1. Meanwhile, the levels of transcripts of heat shock protein genes in response to heat stress were similar in both hit4-1 and wild-type plants. Collectively, these results demonstrated that HIT4 defines a new TGS regulator that acts at the level of heterochromatin organization and is essential for basal thermotolerance in plants.

The Role of Oxidative Stress in Vitiligo: An Update on Its Pathogenesis and Therapeutic Implications.

Vitiligo is an autoimmune skin disorder caused by dysfunctional pigment-producing melanocytes which are attacked by immune cells. Oxidative stress is considered to play a crucial role in activating consequent autoimmune responses related to vitiligo. Melanin synthesis by melanocytes is the main intracellular stressor, producing reactive oxygen species (ROS). Under normal physiological conditions, the antioxidative nuclear factor erythroid 2-related factor 2 (Nrf2) pathway functions as a crucial mediator for cells to resist oxidative stress. In pathological situations, such as with antioxidant defects or under inflammation, ROS accumulate and cause cell damage. Herein, we summarize events at the cellular level under excessive ROS in vitiligo and highlight exposure to melanocyte-specific antigens that trigger immune responses. Such responses lead to functional impairment and the death of melanocytes, which sequentially increase melanocyte cytotoxicity through both innate and adaptive immunity. This report provides new perspectives and advances our understanding of interrelationships between oxidative stress and autoimmunity in the pathogenesis of vitiligo. We describe progress with targeted antioxidant therapy, with the aim of providing potential therapeutic approaches.