Malignant peripheral nerve sheath tumor in children: A single-institute retrospective analysis

Malignant peripheral nerve sheath tumors are rare tumors that originate from Schwann cells. Patients with neurofibromatosis type 1 are prone to develop these tumors. Due to their rarity and lack of established treatment, the prognosis of malignant peripheral nerve sheath tumors is poor. A retrospective study was conducted on children treated for malignant peripheral nerve sheath tumors at the Seoul National University Children's Hospital between 2007 and 2016. Eleven patients were diagnosed with malignant nerve sheath tumors at a median age of 12 years, eight of whom had neurofibromatosis type 1. All the patients underwent chemotherapy and received surgical resection, and 5 patients relapsed. The 2-year overall survival rate was 72.7%, and the 2-year event-free survival rate was 58.2%. Univariate analysis was performed to assess the correlations between the clinical factors. There was no statistically significant difference in the overall survival rate according to the patients' clinical factors. However, there was a decreasing trend in the relationship between the event-free survival rate and the prevalence of neurofibromatosis type 1. Regular follow up of neurofibromatosis type 1. Regular follow-up of neurofibromatosis type 1 patients may identify detection of early relapse of malignant peripheral nerve sheath tumors. Genetic studies of these patients and tumors may identify opportunities for targeted therapy.

Comparison of Efficacy and Safety Between Propranolol and Steroid for Infantile Hemangioma: A Randomized Clinical Trial

Importance

There are limited data from randomized clinical trials comparing propranolol and steroid medication for treatment of infantile hemangioma (IH).

Objective

To determine the efficacy and safety of propranolol compared with steroid as a first-line treatment for IH.

Design, Setting, and Participants

This randomized clinical noninferiority trial tested the efficacy and safety of propranolol vs steroid treatment for IH at a single academic hospital. All participants were diagnosed with IH between June 2013 and October 2014, had normal heart function, and had not been previously treated for IH.

Interventions

The participants were randomly assigned to either the propranolol group or the steroid group. In the propranolol group, the patients were admitted, observed for adverse effects for 3 days after treatment initiation, and then released and treated as outpatients for 16 weeks (2 mg/kg/d). In the steroid group, the patients were seen as outpatients from the beginning and were also treated for 16 weeks (2 mg/kg/d).

Main Outcomes and Measures

The primary efficacy variable was the response to treatment at 16 weeks, which was evaluated by the hemangioma volume using magnetic resonance imaging before and at 16 weeks after treatment initiation. While comparing the effect of medication between the groups, we monitored the adverse effects of both drugs.

Results

A total of 34 patients (15 boys, 19 girls; mean age, 3.3 months; range, 0.3-8.2 months) were randomized to receive either propranolol or steroid treatment (17 in each treatment group). Guardians for 2 patients in the steroid group withdrew their consent, and 1 patient in the propranolol group did not complete the efficacy test. The intention-to-treat analysis, applying multiple imputations, found the treatment response rate in the propranolol group to be 95.65%, and that of the steroid group was 91.94%. Because the difference in response rate between the groups was 3.71%, propranolol was considered noninferior. We found that there was no difference between the groups in safety outcomes.

Conclusions and Relevance

Our trial demonstrated that propranolol was not inferior to steroid with respect to therapeutic effects in IH.

Trial Registration

clinicaltrials.gov Identifier: NCT01908972.

Oligomeric Procyanidins (OPCs) Inhibit Procollagen Type I Secretion of Fibroblasts

Wound healing is composed of a complex process that requires harmonies of various cell populations where fibroblasts play the main role. Oligomeric procyanidins (OPC) are main components of grape (Vitis vinifera) seed extracts, and recent studies showed OPC's effects on inflammation, cell migration, and proliferation. We investigated the effect of OPC on fibroblasts to regulate wound healing process. Human dermal fibroblast known as Hs27 cells were treated with various concentrations of OPC (0, 2.5, 5, 10, and 20 μg/μl). Cell cytotoxicity was evaluated by the Cell Counting Kit assay, and the expression levels of secreted procollagen were analyzed. Procollagen levels in OPC treated cells exposed to transforming growth factor beta 1 (TGF-β1) or ascorbic acid were evaluated using Western blot and immunocytochemistry. Relative mRNA expressions of procollagen, molecular chaperone such as HSP47, P4H were determined by real-time PCR in OPC treated cells. OPC showed no cytotoxicity on Hs27 cells at every concentration but inhibited procollagen secretion in a dose-dependent manner. The inhibitory effect also appeared under TGF-β1 induced collagen overproduction. Immunocytochemistry showed that higher levels of intracytoplasmic procollagen were accumulated in TGF-β1 treatment group, whereas ascorbic acid induced a release of accumulated procollagen under OPC treatment. The mRNA expressions of procollagen, molecular chaperone were not affected by OPC, but procollagen level was increased when exposed to TGF-β1. OPC inhibits procollagen secretion from fibroblasts with no effects on cell proliferations even under the environment of TGF-β1-induced collagen overproduction. OPC could regulate the diseases and symptoms of abnormal overabundant collagen production.

Regeneration of full-thickness skin defects by differentiated adipose-derived stem cells into fibroblast-like cells by fibroblast-conditioned medium

Background

Fibroblasts are ubiquitous cells in the human body and are absolutely necessary for wound healing such as for injured skin. This role of fibroblasts was the reason why we aimed to differentiate human adipose-derived stem cells (hADSCs) into fibroblasts and to test their wound healing potency. Recent reports on hADSC-derived conditioned medium have indicated stimulation of collagen synthesis as well as migration of dermal fibroblasts in wound sites with these cells. Similarly, human fibroblast-derived conditioned medium (F-CM) was reported to contain a variety of factors known to be important for growth of skin. However, it remains unknown whether and how F-CM can stimulate hADSCs to secrete type I collagen.

Methods

In this study, we obtained F-CM from the culture of human skin fibroblast HS27 cells in DMEM media. For an in-vivo wound healing assay using cell transplantation, balb/c nude mice with full-thickness skin wound were used.

Results

Our data showed that levels of type I pro-collagen secreted by hADSCs cultured in F-CM increased significantly compared with hADSCs kept in normal medium for 72 h. In addition, from a Sircol collagen assay, the amount of collagen in F-CM-treated hADSC conditioned media (72 h) was markedly higher than both the normal medium-treated hADSC conditioned media (72 h) and the F-CM (24 h). We aimed to confirm that hADSCs in F-CM would differentiate into fibroblast cells in order to stimulate wound healing in a skin defect model. To investigate whether F-CM induced hADSCs into fibroblast-like cells, we performed FACS analysis and verified that both F-CM-treated hADSCs and HS27 cells contained similar expression patterns for CD13, CD54, and CD105, whereas normal medium-treated hADSCs were significantly different. mRNA level  analysis for Nanog, Oct4A, and Sox2 as undifferentiation markers and vimentin, HSP47, and desmin as matured fibroblast markers supported the characterization that hADSCs in F-CM were highly differentiated into fibroblast-like cells. To discover the mechanism of type I pro-collagen expression in hADSCs in F-CM, we observed that phospho-smad 2/3 levels were increased in the TGF-β/Smad signaling pathway. For in-vivo analysis, we injected various cell types into balb/c nude mouse skin carrying a 10-mm punch wound, and observed a significantly positive wound healing effect in this full-thickness excision model with F-CM-treated hADSCs rather than with untreated hADSCs or the PBS injected group.

Conclusions

We differentiated F-CM-treated hADSCs into fibroblast-like cells and demonstrated their efficiency in wound healing in a skin wound model.

Environmental enrichment enhances synaptic plasticity by internalization of striatal dopamine transporters

Environmental enrichment (EE) with a complex combination of physical, cognitive and social stimulations enhances synaptic plasticity and behavioral function. However, the mechanism remains to be elucidated in detail. We aimed to investigate dopamine-related synaptic plasticity underlying functional improvement after EE. For this, six-week-old CD-1 mice were randomly allocated to EE or standard conditions for two months. EE significantly enhanced behavioral functions such as rotarod and ladder walking tests. In a [¹⁸F]FPCIT positron emission tomography scan, binding values of striatal DAT were significantly decreased approximately 18% in the EE mice relative to the control mice. DAT inhibitor administrated to establish the relationship of the DAT down-regulation to the treatment effects also improved rotarod performances, suggesting that DAT inhibition recapitulated EE-mediated treatment benefits. Next, EE-induced internalization of DAT was confirmed using a surface biotinylation assay. In situ proximity ligation assay and immunoprecipitation demonstrated that EE significantly increased the phosphorylation of striatal DAT as well as the levels of DAT bound with protein kinase C (PKC). In conclusion, we suggest that EE enables phosphorylation of striatal DAT via a PKC-mediated pathway and causes DAT internalization. This is the first report to suggest an EE-mediated mechanism of synaptic plasticity by internalization of striatal DAT.

Theranostic Bioabsorbable Bone Fixation Plate with Drug-Layered Double Hydroxide Nanohybrids

A bioabsorbable polymeric bone plate enabled with both diagnostic and therapeutic functionalities (radiopacity and sustained drug release, respectively) is proposed. To this end, a drug-inorganic nanohybrid (RS-LDH) is examined as a theranostic agent by intercalating an anti-resorptive bone remodeling drug, risedronate (RS) into a layered double hydroxide (LDH) via an ion-exchange reaction. The RS-LDH is prepared as a sheet with a biodegradable polymer, poly(lactic-co-glycolic acid), and is then attached onto the clinically approved bioabsorbable bone plate to produce the theranostic plate. Because of the presence of the metals in the LDH, the theranostic plate results in discernible in vivo X-ray images for up to four weeks after implantation. Concurrently, bone regeneration is also significantly improved compared with the other control groups, likely because of this material's sustained drug-release property. The theranostic plate is also largely biocompatible, similar to the plate already approved for clinical use. It is concluded that the combination of a biodegradable bone plate with RS-LDH nanohybrids can constitute a promising system with theranostic ability in both X-ray diagnosis and expedited bone repair.

Improved In Vivo Stability of Radioiodinated Rituximab Using an Iodination Linker for Radioimmunotherapy

PURPOSE

Directly radioiodinated [¹³¹I]-rituximab has been developed as a radioimmunotherapeutic agent in patients with CD20-positive B cell non-Hodgkin's lymphoma. However, there are concerns over its in vivo catabolism and deiodination. A novel radioiodination linker, N-(4-isothiocyanatobenzyl)-2-(3-(tributylstannyl)phenyl) acetamide (IBPA), was synthesized for the preparation of stable radioiodinated proteins.

METHODS

The authors evaluated the potential of IBPA as a stable radioiodinated linker for rituximab. [¹²⁵I]-IBPA was purified and conjugated with rituximab, and in vitro stability testing was performed in serum and liver microsomes. In vivo studies were performed after i.v. injection of [¹²⁵I]-rituximab or [¹²⁵I]-IBPA-rituximab to nude mice.

RESULTS

In in vitro studies, [¹²⁵I]-IBPA-rituximab was stable in serum and liver microsomes. In static scans, high radioactivity was evident in the thyroid following injection of [¹²⁵I]-rituximab, but low radioactivity was seen in the thyroid following injection of [¹²⁵I]-IBPA-rituximab. In biodistribution studies, radioactivity uptake in thyroid glands of [¹²⁵I]-IBPA-rituximab was decreased by approximately sevenfold compared to [¹²⁵I]-rituximab. In pharmacokinetics, the half-life of [¹²⁵I]-rituximab was shorter than that of [¹²⁵I]-IBPA-rituximab in plasma of nude mice.

CONCLUSIONS

The authors demonstrate that [¹²⁵I]-IBPA-rituximab is more stable to metabolic deiodination in vivo than is [¹²⁵I]-rituximab. Radioiodination of rituximab using IBPA is thus preferable to direct labeling in terms of in vivo stability.

Prospective Study on the Intraoperative Blood Loss in Patients with Cleft Palate Undergoing Furlow's Double Opposing Z-Palatoplasty

BACKGROUND

Blood loss during cleft palate surgery has been investigated in previous research, but there is no report regarding blood loss when performing Furlow's double opposing Z-plasty (DOZ). In the present study, we evaluated intraoperative blood loss in patients with cleft palate who underwent the DOZ procedure.

MATERIALS AND METHODS

Intraoperative blood loss was prospectively investigated in 59 patients undergoing palatoplasty with DOZ by a single surgeon between August 2012 and July 2013. Demographic factors and clinical status, including cleft type and palatal gap, were recorded. Blood loss was evaluated by measuring the change in weight of a suction bottle, suction line, and gauze balls.

RESULTS

Mean blood loss was 16.61 ± 10.33 mL, which accounted for 5% of total blood volume. Male sex, older age, severe cleft type, larger palatal gap, relaxed incision, and increased operative time contributed to greater blood loss. The amount of intraoperative bleeding could be predicted by the following equation: Blood loss = -5.64 + 6.18 (male patients) + 7.58 (severe type cleft) + 0.88 X age (months) + 0.84 X palatal gap (mm).

CONCLUSIONS

We found that the DOZ technique causes mild blood loss, but bleeding amount tended to increase in older male patients with a severe cleft and a larger palatal gap. The use of relaxed incisions during palatoplasty and prolonged operation times also contributed to greater blood loss.

Fabrication of three-dimensional scan-to-print ear model for microtia reconstruction

BACKGROUND

Microtia is a congenital deformity of the external ear that occurs in 1 of every 5000 births. Microtia reconstruction using traditional two-dimensional templates does not provide highly detailed ear shapes. Here, we describe the feasibility of using a three-dimensional (3D) ear model as a reference.

MATERIALS AND METHODS

Seven children aged from 11 to 16 (6 grade III and 1 grade II microtia) were recruited from Seoul National University Children's Hospital, Korea. We generated 3D-computer-aided design models of each patient's ear by performing 3D laser scanning for a mirror-transformed cast of their normal ear. The 3D-printed ear model was used in microtia reconstruction surgery following the Nagata technique, and its shape was compared with the casted ear model.

RESULTS

One patient experienced irritation caused by accidently pouring resin into the external auditory meatus, and another had minor skin necrosis; both complications were successfully treated. The average percentage differences of the superior, inferior, anterior, posterior, and lateral views between the casted and 3D-printed ear models were 1.17%, 1.48%, 1.64%, 1.80%, and 5.44%, respectively (average: 2.31%), where the difference between the casted ear models and traditional two-dimensional templates were 16.03% in average.

CONCLUSIONS

Our results show that simple microtia reconstruction can be performed using 3D ear models. The 3D-printed ear models of each patient were consistent and accurately represented the thickness, depth, and height of the normal ear. The availability of the 3D-printed ear model in the operating room reduced the amount of unnecessary work during surgery.

Targeted therapy for Epstein-Barr virus-associated gastric carcinoma using low-dose gemcitabine-induced lytic activation

The constant presence of the viral genome in Epstein-Barr virus (EBV)-associated gastric cancers (EBVaGCs) suggests the applicability of novel EBV-targeted therapies. The antiviral nucleoside drug, ganciclovir (GCV), is effective only in the context of the viral lytic cycle in the presence of EBV-encoded thymidine kinase (TK)/protein kinase (PK) expression. In this study, screening of the Johns Hopkins Drug Library identified gemcitabine as a candidate for combination treatment with GCV. Pharmacological induction of EBV-TK or PK in EBVaGC-originated tumor cells were used to study combination treatment with GCV in vitro and in vivo. Gemcitabine was found to be a lytic inducer via activation of the ataxia telangiectasia-mutated (ATM)/p53 genotoxic stress pathway in EBVaGC. Using an EBVaGC mouse model and a [¹²⁵I] fialuridine (FIAU)-based lytic activation imaging system, we evaluated gemcitabine-induced lytic activation in an in vivo system and confirmed the efficacy of gemcitabine-GCV combination treatment. This viral enzyme-targeted anti-tumor strategy may provide a new therapeutic approach for EBVaGCs.

Enhanced tumor retention of radioiodinated anti-epidermal growth factor receptor antibody using novel bifunctional iodination linker for radioimmunotherapy

Radioimmunotherapy (RIT) uses an antibody labeled with a radionuclide to deliver cytotoxic radiation to a target tumor cells. Radioiodine is most commonly employed to prepare radiolabeled proteins (antibodies, peptides) for in vitro and in vivo applications. A major shortcoming of radioiodinated proteins prepared by direct labeling methods is their deiodination in vivo. For the preparation of more stable radioiodinated antibodies, we developed a new linker (N-(4-isothiocyanatobenzyl)-2-(3-(tributylstannyl)phenyl) acetamide (IBPA). This study evaluated the usefulness of IBPA as a linker for the stable radioiodinated internalizing antibody, cetuximab. Directly labeled cetuximab ([¹²⁵I]-cetuximab) was prepared by the chloramine T method. To prepare indirectly labeled cetuximab using IBPA ([¹²⁵I]-IBPA-cetuximab), IBPA was radioiodinated using chloramine-T to give N-(4-isothiocyanatobenzyl)-2-(3-[¹²⁵I]phenyl)acetamide ([¹²⁵I]-IBPA), which was purified by high performance liquid chromatography. [¹²⁵I]-IBPA was then conjugated to cetuximab. In vitro target binding and internalizing assays were performed in PC9, LS174T, and FaDu cell lines. In vivo planar images were obtained using an Inveon SPECT scanner 3, 24, 48, and 168 h after i.v. injection of [¹²⁵I]-cetuximab or [¹²⁵I]-IBPA-cetuximab in athymic mice bearing LS174T tumor xenografts. Specific binding and internalized radioactivity of [¹²⁵I]-IBPA-cetuximab were higher than those of [¹²⁵I]-cetuximab in PC9, LS174T, and FaDu cell lines. In planar images scant radioactivity was evident in thyroid glands after injection of [¹²⁵I]-IBPA-cetuximab, while a high level of radioactivity was present in thyroid glands after injection of [¹²⁵I]-cetuximab. Tumor uptake value of [¹²⁵I]-IBPA-cetuximab was higher than that of [¹²⁵I]-cetuximab for up to 168 h. [¹²⁵I]-IBPA-cetuximab is stable and resistant to deiodination in vivo. IBPA is a promising bi-functional linker for radioiodination of internalizing monoclonal antibodies for in vivo applications including radioimmunotherapy.

A new method of fabricating a blend scaffold using an indirect three-dimensional printing technique

Due to its simplicity and effectiveness, the physical blending of polymers is considered to be a practical strategy for developing a versatile scaffold having desirable mechanical and biochemical properties. In the present work, an indirect three-dimensional (i3D) printing technique was proposed to fabricate a 3D free-form scaffold using a blend of immiscible materials, such as polycaprolactone (PCL) and gelatin. The i3D printing technique includes 3D printing of a mold and a sacrificial molding process. PCL/chloroform and gelatin/water were physically mixed to prepare the blend solution, which was subsequently injected into the cavity of a 3D printed mold. After solvent removal and gelatin cross-linking, the mold was dissolved to obtain a PCL-gelatin (PG) scaffold, with a specific 3D structure. Scanning electron microscopy and Fourier transform infrared spectroscopy analysis indicated that PCL masses and gelatin fibers in the PG scaffold homogenously coexisted without chemical bonding. Compression tests confirmed that gelatin incorporation into the PCL enhanced its mechanical flexibility and softness, to the point of being suitable for soft-tissue engineering, as opposed to pure PCL. Human adipose-derived stem cells, cultured on a PG scaffold, exhibited enhanced in vitro chondrogenic differentiation and tissue formation, compared with those on a PCL scaffold. The i3D printing technique can be used to blend a variety of materials, facilitating 3D scaffold fabrication for specific tissue regeneration. Furthermore, this convenient and versatile technique may lead to wider application of 3D printing in tissue engineering.

Cranial distraction osteogenesis: a proposal of minimal consolidation period

PURPOSE

Cranial distraction osteogenesis (DO) has many advantages for correcting skull deformities: Thus, DO is extensively used for the treatment of skull deformities. However, diverse, unexpected complications are associated with this procedure. In this study, we present the surgical outcomes and complications of DO. Moreover, we propose a modified protocol for DO to reduce complications.

METHODS

This is a retrospective study on managed patients that underwent DO between March 2008 and May 2013. Their clinical courses were reviewed. Distraction protocols were individually inspected, and the final surgical outcomes, including complications, were evaluated.

RESULTS

During the study period, a total of ten patients (seven boys and three girls) were treated at our institute. The median distraction period was 20.5 days (ranging from 17 to 50 days). The range of total distraction length was 19-22 mm. The median consolidation period was 96 days (ranging from 0 to 343 days). All patients achieved the goals of distraction. At follow-up evaluations, all patients, except one, showed good surgical outcomes in both head shape and neurologic symptoms. There were six patients with wound complications during the treatment period. Among them, the distractors were removed early in three patients. Interestingly, even these three patients, without a sufficient consolidation period, showed good outcomes.

CONCLUSIONS

Although DO has many merits for correcting skull deformities, it frequently causes severe wound complications. To reduce these complications, we propose a modified protocol with a minimal or even no consolidation period.

Self-assembling peptide nanofibers coupled with neuropeptide substance P for bone tissue engineering

The number of patients requiring flat bone transplantation continues to increase worldwide. Cell transplantation has been successfully applied clinically; however, it causes another defect site and the time requirements to harvest cells and expand them are considerable. In this study, KLD12/KLD12-SP (KLD12+KLD12-substance P [SP]) was designed to mimic endogenous tissue-healing processes. The structures of KLD12, KLD12-SP, and KLD12/KLD12-SP were observed by transmission electron microscopy and circular dichroism spectra. KLD12/KLD12-SP nanofibers (5-10 nm) were created under physiological conditions by formation of a β-sheet structure. The ability of mesenchymal stem cells (MSCs) to recruit KLD12/KLD12-SP was observed by using an in vivo fluorescence imaging system. Labeled human bone marrow stromal cells supplied via an intravenous injection were recruited to the scaffold containing KLD12/KLD12-SP. Polylactic acid/beta-tricalcium phosphate (PLA/β-TCP) scaffolds filled with KLD12/KLD12-SP were applied to repair calvarial defects. The composite constructs (groups: defect, PLA/β-TCP, PLA/β-TCP/KLD12, and PLA/β-TCP/KLD12/KLD12-SP) were implanted into rat defect sites. Bone tissue regeneration was evaluated by observing gross morphology by hematoxylin and eosin and Masson's trichrome staining at 12 and 24 weeks after surgery. Gross morphology showed that the defect site was filled with new tissue that was integrated with host tissue in the KLD12/KLD12-SP group. In addition, from the staining data, cells were recruited to the defect site and lacunae structures formed in the KLD12/KLD12-SP group. From these results, the PLA/β-TCP+KLD12/KLD12-SP composite construct was considered for enhancement of bone tissue regeneration without cell transplantation.

Alleviation of capsular formations on silicone implants in rats using biomembrane-mimicking coatings

Despite their popular use in breast augmentation and reconstruction surgeries, the limited biocompatibility of silicone implants can induce severe side effects, including capsular contracture - an excessive foreign body reaction that forms a tight and hard fibrous capsule around the implant. This study examines the effects of using biomembrane-mimicking surface coatings to prevent capsular formations on silicone implants. The covalently attached biomembrane-mimicking polymer, poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC), prevented nonspecific protein adsorption and fibroblast adhesion on the silicone surface. More importantly, in vivo capsule formations around PMPC-grafted silicone implants in rats were significantly thinner and exhibited lower collagen densities and more regular collagen alignments than bare silicone implants. The observed decrease in α-smooth muscle actin also supported the alleviation of capsular formations by the biomembrane-mimicking coating. Decreases in inflammation-related cells, myeloperoxidase and transforming growth factor-β resulted in reduced inflammation in the capsular tissue. The biomembrane-mimicking coatings used on these silicone implants demonstrate great potential for preventing capsular contracture and developing biocompatible materials for various biomedical applications.