Activin A downregulates the CD69-MT2A axis via p38MAPK to induce erythroid differentiation that sensitizes BCR-ABL-positive cells to imatinib.

Induction of differentiation sensitizes chronic myeloid leukemia (CML) cells to the BCR-ABL inhibitor imatinib by mechanisms that remain unknown. We previously identified the BCR-ABL downstream effector CD69 which inhibits imatinib-induced CML cell differentiation. Herein, we found that the erythroid differentiation inducers activin A and aclacinomycin A induced expression of erythroid markers (α-globin, ζ-globin, GATA-1, and glycophorin A) and simultaneously reduced CD69 levels in K562 CML cells. Blockade of p38MAPK by SB203580 and shRNA eliminated the inhibitory effect of activin A on the promoter, mRNA, and protein levels and positive cell population of CD69. CD69 overexpression inhibited activin A-induced erythroid marker expression. Pretreatment of K562 cells with activin A to induce differentiation followed by a subtoxic concentration of imatinib caused growth inhibition and apoptosis that was reduced by CD69 overexpression. Activin A also reduced the expression of CD69's potential downstream molecule metallothionein 2A (MT2A) via p38MAPK. MT2A-knockdown reduced CD69 inhibition of activin A-induced erythroid marker expression. Furthermore, MT2A-knockdown reduced CD69 inhibition of activin A-imatinib sequential treatment-mediated growth inhibition and apoptosis in K562 and BCR-ABL-expressing CD34+ cells. These results suggest that CD69 inhibits activin A induction of erythroid differentiation-mediated CML cell sensitivity to imatinib via MT2A. Therefore, activin A induction of erythroid differentiation sensitizes BCR-ABL-positive cells to imatinib by downregulating the erythroid differentiation suppressors CD69 and MT2A.

Thromboembolic Presentations among Patients Hospitalized to the Intensive Care Unit for Coronavirus Disease 2019 (COVID-19) - A Northern Taiwan Single Center Experience.

Coronavirus Disease 2019 (COVID-19) has been associated with a high thromboembolic risk among patients in intensive care units. Asian populations may share a similar thromboembolic risk, but with a higher prevalence of arterial thromboembolism than venous thromboembolism. To clarify this risk in Taiwan, this single-center retrospective study collected 27 consecutive intensive care unit patients with COVID-19 confirmed by polymerase chain reaction, with a median age of 67.6 years (male 81.5%). Twenty-three patients received prophylactic anticoagulation (85.2%), and there were four bleeding events (14.8%). Nine patients had thromboembolism (33.3%), including three with deep vein thrombosis, two with peripheral artery thromboembolism, and four with ischemic stroke. There were no significant clinical differences between the patients with or without thromboembolism. Initial serum ferritin [adjusted odds ratio (OR): 13.19, 95% confidence interval (CI): 1.01-172.07] and peak serum procalcitonin (adjusted OR: 18.93, 95% CI: 1.08-330.91) were associated with a higher risk of thromboembolism. Furthermore, prophylactic anticoagulation (adjusted OR: 0.01, 95% CI: < 0.001-0.55) was associated with a lower risk of thromboembolism. All cases of deep vein thrombosis and one peripheral artery thromboembolism occurred at intravascular catheter locations. No association between thromboembolism and survival was found (age-adjusted hazard ratio: 0.55, 95% CI: 0.10-2.95). In conclusion, the prevalence of COVID-19 thromboembolism among Taiwanese patients in intensive care units was high, even with prophylactic anticoagulation. Serum ferritin and procalcitonin may identify high-risk populations. Prophylactic anticoagulation may reduce the risk of thromboembolism with a manageable bleeding risk. Larger prospective studies are needed to clarify the risk of COVID-19 thromboembolism and its risk factors in the post-Omicron era.

Deficiency in Androgen Receptor Aggravates Traumatic Brain Injury-Induced Pathophysiology and Motor Deficits in Mice.

Androgens have been shown to have a beneficial effect on brain injury and lower reactive astrocyte expression after TBI. Androgen receptors (ARs) are known to mediate the neuroprotective effects of androgens. However, whether ARs play a crucial role in TBI remains unknown. In this study, we investigated the role of ARs in TBI pathophysiology, using AR knockout (ARKO) mice. We used the controlled cortical impact model to produce primary and mechanical brain injuries and assessed motor function and brain-lesion volume. In addition, the AR knockout effects on necrosis and autophagy were evaluated after TBI. AR knockout significantly increased TBI-induced expression of the necrosis marker alpha-II-spectrin breakdown product 150 and astrogliosis marker glial fibrillary acidic protein. In addition, the TBI-induced astrogliosis increase in ARKO mice lasted for three weeks after a TBI. The autophagy marker Beclin-1 was also enhanced in ARKO mice compared with wild-type mice after TBI. Our results also indicated that ARKO mice showed a more unsatisfactory performance than wild-type mice in a motor function test following TBI. Further, they were observed to have more severe lesions than wild-type mice after injury. These findings strongly suggest that ARs play a role in TBI.

Comparison of the Phytochemical Properties, Antioxidant Activity and Cytotoxic Effect on HepG2 Cells in Mongolian and Taiwanese Rhubarb Species.

The Mongolian rhubarb-Rheum undulatum L. (RU)-and Rumex crispus L. (RC)-a Taiwanese local rhubarb belonging to the family of Polygonaceae-are principal therapeutic materials in integrative medicine due to their rich quantities of bioactive compounds; however, their phytochemical and antioxidant properties, and anti-cancer activity is poorly investigated. Furthermore, the phytochemical characteristics of both species may be affected by their different geographical distribution and climatic variance. The current study aimed to compare RU with RC extracts in different polarity solvents (n-hexane, ethyl acetate, acetone, ethanol, and water) for their phytochemical contents including the total phenolic content (TPC), total anthraquinone content (TAC), total flavonoid content (TFC), antioxidant and free radical scavenging capacities, and anticancer ability on the HepG2 cell. Except for the n-hexane extract, all of the RU extracts had considerably higher TPCs than RC extracts, ranging from 8.39 to 11.16 mg gallic acid equivalent (GAE) per gram of dry weight, and the TPCs of each extract were also significantly correlated with their antioxidant capacities by ABTS, DPPH, and FRAP assays (p < 0.05). Moreover, there was no remarkable association between the antioxidant capacities and either TACs or TFCs in both the RU and RC extracts. Besides, high-performance liquid chromatography (HPLC) analysis revealed that both the RU and RC extracts contained chrysophanol, emodin, and physcion, and those bioactive compounds were relatively higher in the n-hexane solvent extracts. Additionally, we observed different levels of dose-dependent cytotoxic effects in all the extracts by cell viability assay. Notably, the ethanol extract of RU had a compelling cytotoxic effect with the lowest half-maximum inhibition concentration (IC50-171.94 ± 6.56 µg/mL at 48 h) among the RU extracts than the ethanol extract of RC. Interestingly, the ethanol extract of RU but not RC significantly induced apoptosis in the human liver cancer cell line, HepG2, with a distinct pattern in caspase-3 activation, resulting in increased PARP cleavage and DNA damage. In summary, Mongolian Rhubarb, RU, showed more phytochemical contents, as well as a higher antioxidant capacity and apoptotic effect to HepG2 than RC; thus, it can be exploited for the proper source of natural antioxidants and liver cancer treatment in further investigation.

Pro-apoptotic effect of haem oxygenase-1 in human colorectal carcinoma cells via endoplasmic reticular stress.

Several biological effects of haem oxygenase (HO)-1, including anti-inflammatory, antiapoptotic and antioxidative properties were reported; however, the role of HO-1 in apoptosis is still unclear. In the presence of stimulation by cobalt protoporphyrin (CoPP), an HO-1 inducer, apoptotic characteristics were observed, including DNA laddering, hypodiploid cells, and cleavages of caspase (Casp)-3 and poly(ADP) ribose polymerase (PARP) proteins in human colon carcinoma COLO205, HCT-15, LOVO and HT-29 cells in serum-free (SF) conditions with increased HO-1, but not heat shock protein 70 (HSP70) or HSP90. The addition of 10% foetal bovine serum (FBS) or 1% bovine serum albumin accordingly inhibited CoPP-induced apoptosis and HO-1 protein expression in human colon cancer cells. CoPP-induced apoptosis of colon cancer cells was prevented by the addition of the pan-caspase inhibitor, Z-VAD-FMK (VAD), and the Casp-3 inhibitor, Z-DEVD-FMK (DEVD). N-Acetyl cysteine inhibited reactive oxygen species-generated H2 O2 -induced cell death with reduced intracellular peroxide production, but did not affect CoPP-induced apoptosis in human colorectal carcinoma (CRC) cells. Two CoPP analogs, ferric protoporphyrin and tin protoporphyrin, did not affect the viability of human CRC cells or HO-1 expression by those cells, and knockdown of HO-1 protein expression by HO-1 small interfering (si)RNA reversed the cytotoxic effect elicited by CoPP. Furthermore, the carbon monoxide (CO) donor, CORM, but not FeSO4 or biliverdin, induced DNA ladders, and cleavage of Casp-3 and PARP proteins in human CRC cells. Increased phosphorylated levels of the endoplasmic reticular (ER) stress proteins, protein kinase R-like ER kinase (PERK), and eukaryotic initiation factor 2α (eIF2α) by CORM and CoPP were identified, and the addition of the PERK inhibitor, GSK2606414, inhibited CORM- and CoPP-induced apoptosis. Increased GRP78 level and formation of the HO-1/GRP78 complex were detected in CORM- and CoPP-treated human CRC cells. A pro-apoptotic role of HO-1 against the viability of human CRC cells via induction of CO and ER stress was firstly demonstrated herein.

Activation of PERK in ET-1- and thrombin-induced pulmonary fibroblast differentiation: Inhibitory effects of curcumin.

In the present study, we investigated the role of PKR-like endoplasmic reticular kinase (PERK), an endoplasmic reticulum (ER) stress kinase, in endothelin 1 (ET-1)- and thrombin-induced pulmonary fibrosis (PF), and the preventive effects of curcumin (CUR). Using the human embryonic WI-38 lung fibroblast cell line, ET-1 and thrombin induced the expression of ER stress-related proteins (CCAAT-enhancer-binding protein homologous protein, PERK, and binding immunoglobulin protein), a profibrogenic factor (cellular communication network factor 2 [CCN2]), and differentiation markers including α-smooth muscle actin (α-SMA), collagen I (Col I), and Col IV. Knockdown of PERK expression via small interfering RNA (siRNA) significantly reduced the increases in CCN2, α-SMA, Col I, and Col IV proteins in WI-38 cells according to western blot analysis and immunohistochemistry (IHC). Activation of c-Jun N-terminal kinase (JNK) was observed in ET-1- and thrombin-treated WI-38 cells, and the addition of a JNK inhibitor (SP) suppressed the induction of the indicated proteins by ET-1 and thrombin. Thapsigargin (TG), an ER stress inducer, elevated expressions of PERK and ER stress-related proteins with increased differentiation of WI-38 cells. Knockdown of PERK by siRNA or the PERK inhibitor glycogen synthesis kinase reduced expressions of the differentiation markers, α-SMA and Col IV, in WI-38 cells. CUR concentration-dependently inhibited ET-1- or thrombin-induced CCN2, α-SMA, and vimentin proteins with decreased levels of phosphorylated mitogen-activated protein kinase and PERK in WI-38 cells. An in vivo bleomycin-induced PF study showed that an intraperitoneal injection of CUR (30 mg/kg) reduced expressions of α-SMA, CCN2, Col IV, and vimentin in lung tissues via IHC staining using specific antibodies. This study is the first to demonstrate that PERK activation contributes to pulmonary fibroblast differentiation elicited by ET-1 or thrombin, and the inhibitory activity of CUR against PF is demonstrated herein.

Palladium-Catalyzed Sequential Twofold Nucleophilic Substitution on 3-Bromopenta-2,4-dienyl Phosphate: Preparation of C1- and C2-Symmetric Doubly Functionalized Allenes.

Readily available 3-bromopenta-2,4-dienyl esters (1x, acetate; 1y, benzoate; 1z, diethyl phosphate) were applied to the palladium-catalyzed reaction with various soft nucleophiles. The reaction proceeded through the twofold nucleophilic substitution via formal SN2'- and SN2-processes, giving the various doubly functionalized allenes 2 in good yields. In the reactions of carboxylates 1x and 1y, the first substitution took place at the C-Br bond to form (allenyl)methyl ester intermediates 3. Because the second substitution on 3 proceeded faster than the first substitution on 1x or 1y, 3 was not isolable, and C2-symmetric allenes 2 were obtained even in the presence of remaining 1x and 1y. On the other hand, the phosphate moiety was more reactive than the C-Br moiety in 1z. The initial products from 1z were 5-Nu-3-bromopenta-1,3-dienes 4, which were less reactive than 1z. Monosubstitution products 4 were isolable, and the stepwise introduction of two different Nu groups in C1-symmetric allenes 2 was realized starting with 1z under the controlled reaction conditions. By the use of a chiral palladium catalyst, axially chiral doubly functionalized allenes were obtained up to 95% ee.

Nilotinib induction of melanogenesis via reactive oxygen species-dependent JNK activation in B16F0 mouse melanoma cells.

Nilotinib (AMN), a second-generation tyrosine kinase inhibitor, induces apoptosis in various cancer cells, and our recent study showed that AMN effectively reduced the viability of human ovarian cancer cells via mitochondrion-dependent apoptosis. The effect of AMN in the melanogenesis of melanoma cells is still unclear. In the present study, we found that the addition of AMN but not imatinib (STI) significantly increased the darkness of B16F0 melanoma cells, and the absorptive value increased with the concentration of AMN. A decrease in the viability of B16F0 cells by AMN was detected in a concentration-dependent manner, accompanied by increased DNA ladders, hypodiploid cells and cleavage of the caspase-3 protein. An in vitro tyrosinase (TYR) activity assay showed that increased TYR activity by AMN was detected in a concentration-dependent manner; however, induction of TYR activity by STI at a concentration of 40 µmol/L was observed. Increased intracellular peroxide by AMN was detected in B16F0 cells, and application of the antioxidant, N-acetylcysteine (NAC), significantly reduced AMN-induced peroxide production which also reduced the darkness of B16F0 cells. Additionally, AMN induced c-Jun N-terminal kinase (JNK) protein phosphorylation in B16F0 cells, which was inhibited by the addition of NAC. AMN-induced melanogenesis of B16F0 cells was significantly inhibited by the addition of NAC and the JNK inhibitor, SP600125 (SP). Data of Western blotting showed that increased protein levels of melanogenesis-related enzymes of tyrosinase-related protein-1 (TRP1), TRP2 and TYR were observed in AMN-treated B16F0 cells which were inhibited by the addition of NAC and SP. Evidence is provided supporting AMN effectively inducing the melanogenesis of B16F0 melanoma cells via reactive oxygen species-dependent JNK activation.

MPT0B169 and MPT0B002, New Tubulin Inhibitors, Induce Growth Inhibition, G2/M Cell Cycle Arrest, and Apoptosis in Human Colorectal Cancer Cells.

We previously synthesized new tubulin inhibitors, MPT0B169 and MPT0B002, which induced growth inhibition and apoptosis in leukemia cells. However, their effects on solid tumor cells have not been determined. In this study, we investigated the effects of MPT0B169 and MPT0B002 on glioblastoma, breast, lung, and colorectal cancer (CRC) cell lines. A cell viability analysis showed that MPT0B169 and MPT0B002 were more effective in inhibiting the proliferation of COLO205 and HT29 CRC cells than U87MG and GBM8401 glioblastoma, MCF-7 and MDA-MB-231 breast cancer, and A549 lung cancer cells. MPT0B169 and MPT0B002 inhibited growth of COLO205 and HT29 cells in dose- and time-dependent manners. A colony-formation assay confirmed the growth inhibitory effects of MPT0B169 and MPT0B002 on COLO205 and HT29 cells. MPT0B169 and MPT0B002 disrupted tubulin polymerization and arrested the cell cycle at the G2/M phase, with a concomitant increase of the cyclin B1 level. MPT0B169 and MPT0B002 induced apoptosis, accompanied by induction of the intrinsic apoptotic pathway, as shown by a reduction in the caspase-9 level and increases in cleaved caspase-3 and cleaved PARP. These results suggest that MPT0B169 and MPT0B002, new tubulin inhibitors, induced growth inhibition, G2/M arrest, and apoptosis in COLO205 and HT29 cells, and they could potentially be anticancer agents for CRC cells.

Perforator flap based on the third perforator of the profunda femoris artery (PFA)-assisted closure of the free vertical posteromedial thigh (vPMT) flap donor site.

INTRODUCTION: The primary closure of the vertical posteromedial thigh (vPMT) free flap donor site is very important to minimize donor site morbidity and maximize cosmetic appearance. However, sometimes due to the dimension of the defect, a vPMT flap is wider than the 8-10 cm requirement. The authors report their experience with the third perforator of the profunda femoris artery (PFA) during the vPMT free flap donor-site closure. PATIENTS AND METHODS: Between January 2016 and December 2017, 5 patients underwent reconstruction of lower extremity (2 pts.) and head and neck (3 pts.) area with the free vPMT flaps. Attempts to close the vPMT free flap donor site directly failed due to the flaps' width (average: 11 cm) and pedicled perforator flaps based on the third perforator of the PFA at the distal thigh were harvested to close the defect primary without the use of a skin graft. The size of perforator flap based on 3rd perforator of PFA was on average 6 cm × 4 cm (ranged: 4-8 cm × 3-6 cm). RESULTS: In all patients, the third perforator of the PFA was identified and the perforator diameter was on average 2.0 mm (range, 1.8-2.2 mm). All perforators were musculocutaneous and single. The dimensions of the flaps were on average 6 cm × 4 cm (range: 4 to 8 cm × 3 to 6 cm). All flaps healed uneventfully without complications and the patients were satisfied with cosmetic and functional results at 6 months follow-up. CONCLUSION: The third perforator of the PFA may be an option to ensure primary closure of the PMT flap donor site, when a larger flap for reconstruction is needed with subsequent impossibility to achieve primary closure of the donor site.

Comprehensive review of vascularized lymph node transfers for lymphedema: Outcomes and complications.

INTRODUCTION: Lymphedema remains a challenging clinical problem. A new field of lymphatic surgery using micro and super microsurgery techniques is a rapidly advancing field aimed to treat recalcitrant cases. The objective of this study was to evaluate outcomes and complications of vascularized lymph node transfer (VLNT). Several early preliminary studies have reported promising outcomes, but they are limited by small numbers, short follow-up, and are inconsistent in addressing the origin and recipient site of the transferred lymph nodes as well as the donor site morbidity. METHODS: A review of literature was conducted using PubMed-MEDLINE, EMBASE for key words vascularized lymph node transfer (also autologous, lymph node transplant). Only human studies were included. RESULTS: A total 24 studies encompassing 271 vascularized lymph node transfers were included. The inguinal nodes were the most commonly used donor site followed by the lateral thoracic lymph nodes. The lateral thoracic lymph nodes were the least effective and had the highest complication rates (27.5%) compared to other lymph node donor sites (inguinal: 10.3% and supraclavicular: 5.6%). Upper extremity lymphedema responded better compared to lower extremity (74.2 vs. 53.2%), but there was no difference in placing the lymph nodes more proximally versus distally on the extremity (proximal: 76.9% vs. distal: 80.4%). CONCLUSION: Vascularized lymph node transfer for lymphedema treatment is a promising operative technique showing beneficial results in early but also in advanced stage lymphedema. This physiologic surgical procedure should be included in a modern reconstructive concept for lymphedema treatment. © 2016 Wiley Periodicals, Inc. Microsurgery 38:222-229, 2018.

The free inverted omega-shaped flap for circumferential hypopharyngeal reconstruction with simultaneous neck skin defect.

BACKGROUND: Circumferential hypopharyngeal defect with simultaneous skin defect can pose complicated reconstructive challenge for reconstructive microsurgeons. Our experience with the versatile inverted-omega flap tubing design is proposed to accommodate such problem. METHODS: From 2012 to 2015, 13 anterolateral thigh (ALT) flaps and one anteromedial thigh (AMT) flap were harvested for reconstruction of circumferential hypopharyngeal defects with skin defects in 14 patients. All patients were males except one. Patient age ranged from 42 to 67 years (average, 53.1 years). Fifty-seven percent were recurrent cases. All but one patient received preoperative chemoradiotherapy. RESULTS: The average flap size was 29 × 8 cm (range: 25-31 × 6-10 cm2 ). An average of 2.6 perforators was included in each flap (2-4 perforators/flap). All flaps survived. One venous thrombosis was noted and salvaged after thrombolectomy and vein graft. The mean follow-up period was 25 months. The fistula rate was 21.4% (three patients). One fistula never healed because of early recurrence; one fistula healed after surgical intervention; and one fistula need a loco-regional flap for secondary reconstruction. Three postoperative strictures were noted (21.4%). CONCLUSION: For the circumferential hypopharyngeal defect with simultaneous neck skin defect, this inverted-omega ALT tubing design offers an alternative choice for such complicated reconstruction. © 2016 Wiley Periodicals, Inc. Microsurgery, 38:51-59, 2018.

Palladium-Catalyzed SN2'-Cyclization of Ambivalent (Bromoalkadienyl)malonates: Preparation of Medium- to Large-Membered Endocyclic Allenes.

A palladium-catalyzed reaction for preparing various endocyclic allenes was developed. The substrates for the reaction were readily available ω-(pronucleophile-tethered)-3-bromo-1,3-alkadienes, and a palladium-catalyst facilitated their unimolecular SN2'-cyclization in the presence of potassium tert-butoxide to give the corresponding 9- to 16-membered endocyclic allenes in fair yields of up to 67% together with the dimeric 16- to 32-membered endocyclic bis-allenes and other oligomeric/polymeric intermolecular reaction products. For higher yields of the monomeric endocyclic allenes, the reaction needed to be conducted under high-dilution conditions. Using a chiral palladium catalyst, axially chiral endocyclic allenes were obtained in up to 70% ee.

The posteromedial thigh (PMT) flap for lower extremity reconstruction.

BACKGROUND: The posteromedial thigh (PMT) perforator flap is a new reliable flap with versatility. The purpose of this article was to report our experience with the use of free PMT flaps for reconstruction of defects of the lower extremity. PATIENTS AND METHODS: From July 2014 to May 2015, 8 patients received reconstruction with 8 free PMT flaps. The defect locations included the heel (1 case), dorsal foot (2 cases), plantar foot (1 case), lateral malleolus (1 case), Achilles tendon (1 case), and tibia (2 cases). Flaps were raised based on the first medial perforator of the profunda femoris artery (PFA) (7 cases) and medial circumflex femoral artery (LCFA) perforator (1 case). The dorsalis pedis artery (3 cases), anterior tibia artery (1 cases), posterior tibial artery (3 cases), and medial sural pedicle (1 case) were dissected as recipient vessels. RESULTS: The flap sizes varied from 10 × 10 to 30 × 11 cm. All the flaps survived completely after surgery. The donor sites were all primarily closed with minimal morbidities. Follow-up observations were conducted for 3-12 months, and all patients had good functional recovery with satisfactory cosmetic results. CONCLUSION: Perforators arising from the PFA in the posterior medial thigh can be used to design pliable fasciocutaneous flaps. The pedicle length and the vessel diameter are adequate for microvascular anastomosis to the lower extremities recipient vessels. The free PMT flap serves as a good new option for reconstructing lower extremity defects. © 2016 Wiley Periodicals, Inc. Microsurgery 37:865-872, 2017.

The vertical posteromedial thigh (vPMT) flap for autologous breast reconstruction: A novel flap design.

BACKGROUND: The vertical posteromedial thigh (vPMT) perforator flap is a new reliable flap with versatility. The purpose of this article was to report our experience with the use of free vPMT flap for reconstruction of the breast. PATIENTS AND METHODS: From May 2015 to December 2015, seven patients received immediate unilateral breast reconstruction with seven free vPMT flaps. The flaps were raised based on the first medial perforator of the profunda femoris artery (PFA). The internal mammary artery and vein were dissected as recipient vessels. RESULTS: The flap sizes varied from 25 × 9 cm to 30 × 10 cm. The average weight of the flap and mastectomy specimen was 431 g (range: 390 to 470 g) and 410 g (range: 360 to 450 g) respectively. The average pedicle length was 10.4 cm (range, 8.5 to 12.5 cm) and the average arterial diameter was 2.1 mm (range, 1.8 to 2.6 mm). All of the flaps survived completely after surgery. The donor sites were all primarily closed with minimal morbidities. Follow-up observations were conducted from 3 to 9 months. All of patients were satisfactory with the reconstruction. CONCLUSION: The vertical vPMT is suitable for breast reconstruction in women with small to moderate breast size; the vertical pattern of the PMT avoids some of the problems related to other flaps with transverse patterns and represents an alternative design that can be successfully used for breast reconstruction. © 2016 Wiley Periodicals, Inc. Microsurgery 37:371-376, 2017.

Pedicled posteromedial thigh (PMT) flap: A new alternative for groin defect reconstruction.

The posterior medial thigh is mainly vascularized by the profunda femoris artery (PFA), which nourishes the adductor magnus muscle and overlying skin, to supply a number of perforators that can potentially be used as pedicles for local perforator flaps. Here we present two cases utilizing the pedicled posteromedial thigh flap (PMT) to reconstruct the groin defects. Two patients underwent resection for metastatic malignant melanoma resulting in large defects of the groin with exposure of major inguinal vessels; the dimensions of the skin defects were 15 cm × 5 cm and 16 cm × 6 cm, two ipsilateral pedicled PMT flaps were designed to cover the defects. The pedicled PMT flaps were based on perforators arising from the PFA and were transposed through a submuscular tunnel into the defect. The postoperative course was uneventful and the wounds were reconstructed successfully. The pedicled PMT flap may be an option for reconstruction of groin defects and could be incorporated into the armamentarium of the reconstructive microsurgeon. © 2015 Wiley Periodicals, Inc. Microsurgery 37:339-343, 2017.

miR-19a, -19b, and -26b Mediate CTGF Expression and Pulmonary Fibroblast Differentiation.

Although microRNA (miRNA) dysregulation with intracellular signaling cascade disruption has been demonstrated in the pathophysiology of pulmonary fibrosis, the relationship between miRNAs and intracellular signaling cascades in pulmonary fibrosis remains unclear. Using the human embryonic lung fibroblast cell line WI-38, we observed endothelin-1 (ET-1)- and thrombin-induced expression of the differentiation markers α-smooth muscle actin (α-SMA) and vimentin along with increased connective tissue growth factor (CTGF) protein expression. Decreased CTGF protein expression by CTGF siRNA significantly blocked ET-1- and thrombin-induced α-SMA and vimentin expression in WI-38 cells. Activation of the mitogen-activated protein kinases (MAPKs) extracellular signal-regulated kinase ERK, c-Jun N-terminal kinase (JNK), and p38 contributed to ET-1- and thrombin-induced CTGF, α-SMA, and vimentin expression in WI-38 cells. TargetScan Human, miRanda, and PicTar prediction algorithms were used to predict miRNAs with binding sites in the 3' untranslated region (UTR) of CTGF mRNA. miR-19a, -19b, and -26b were candidate miRNAs of CTGF. Direct binding of the candidate miRNAs to the 3'-UTR of CTGF mRNA was verified through luciferase assay by using SV40-promoter-IRES-driven luciferase containing the 3'-UTR of CTGF mRNA as a reporter plasmid. ET-1 and thrombin reduced candidate miRNA levels. Candidate miRNA overexpression significantly suppressed ET-1- and thrombin-induced CTGF expression and reduced α-SMA and vimentin expression in the WI-38 cells. Furthermore, candidate miRNA levels were decreased in the lung tissues of mice with bleomycin-induced pulmonary fibrosis, and intratracheal application of miR-19a, -19b, and 26b reduced the pulmonary fibrotic severity induced by bleomycin. This study is the first to demonstrate crosstalk between MAPK activation and reduction in miR-19a, -19b, and -26b expression leading to lung fibroblast differentiation. J. Cell. Physiol. 231: 2236-2248, 2016. © 2016 Wiley Periodicals, Inc.

The "Rolled-Up Sleeve" Technique for Microvascular Venous Anastomosis in Head and Neck Reconstruction: Animal Study and Clinical Series.

BACKGROUND: Venous anastomosis is challenging especially when encountering the thin recipient vein wall in the head and neck region. The authors developed the "rolled-up sleeve" technique to solve this scenario. METHODS: An animal study was performed to access the safety and reliability of the "rolled-up sleeve" technique. This technique was performed in 53 consecutive patients during head and neck reconstruction. RESULTS: In the animal study, all anastomoses were patent. Histological analysis revealed neo-endothelialization over the anastomotic site. This technique was applied to 59 recipient veins: branch of internal jugular vein (27), external jugular vein (17), superficial temporal vein (9), retromandibular vein (4), facial vein (2), and internal mammary vein (2). No venous thrombosis occurred in these clinical series. CONCLUSIONS: The "rolled-up sleeve" technique is a useful procedure that can be performed safely to deal with thin vascular walls for venous anastomoses in head and neck reconstructions.

Combination of Vascular Intervention Surgery and Free Tissue Transfer for Critical Diabetic Limb Salvage.

BACKGROUND: Complex, nontraumatic diabetic foot ulcers with peripheral vascular compromise often lead to extensive lower-limb amputation. The aim of this study is to determine the outcome of combined vascular intervention and free tissue transfer for critical diabetic limb salvage. MATERIALS AND METHODS: A total of 26 consecutive diabetic patients with 28 legs with diabetic foot ulcers who underwent limb salvage with a combination of revascularization (bypass surgery or endovascular angioplasty) and free flap transfers were reviewed. There were 14 male and 12 female patients. The average age was 58.8 years (range, 35-85 years). Amputation-free survival and complete wound healing were defined as the primary endpoints. All preoperative and postoperative data were retrospectively analyzed. RESULTS: Thirty flaps were used for reconstruction in 28 legs, including 21 free anterolateral thigh (ALT) perforator flaps, 3 ALT myocutaneous flaps, 5 gracilis muscle flaps, and 1 latissimus dorsi muscle flap. All flaps used end-to-side anastomoses for the recipient artery and end-to-end anastomoses for the recipient vein. The overall flap success rate was 90% (27/30). Two flaps failed completely because of severe arteriosclerosis, which resulted in anastomosed vessel thrombosis. New flaps were applied in both cases after debridement and trimming of necrotic tissue. One flap failed because of restenosis and inadequate perfusion combined with severe infection, resulting in pedicle thrombosis. A below-knee amputation was subsequently performed. Seven flaps exhibited a partial loss, including 6 ALT perforator flaps and 1 latissimus dorsi flap, because of inadequate margin perfusion. After debridement, the flap revision and wound care, 5 flaps healed uneventfully without additional intervention. The remaining 2 ALT perforator flaps required debridement with a skin graft. The limb-salvage rates were 92.8% after 1 year and 89.2% after 5 years. CONCLUSIONS: The combination of peripheral arterial intervention and free tissue transfer resulted in successful wound healing and limb salvage instead of amputation in select diabetic patients with difficult-to-heal wounds.