Limb Salvage Using Microsurgical Free Tissue Transfer in Severe Frostbite.

PURPOSE: Frostbite is often managed conservatively; however, in severe cases, microsurgical free tissue transfer is required for soft tissue coverage and limb salvage. Given its rarity, the techniques and outcomes of these cases are not well described. The purpose of this report is to present the largest case series, to date, of frostbite injuries requiring microsurgical reconstruction for limb salvage. METHODS: A single-center retrospective review was conducted of all patients who underwent free tissue transfer by a single surgeon from 2008 to 2022. Patients of all ages were included if they suffered a frostbite injury requiring free tissue transfer. Demographics, operative details, and surgical outcomes were recorded. RESULTS: Eight patients with frostbite injuries were included in the report. Patients had frostbite injuries either to the lower extremities (n = 4) or to both upper and lower extremities (n = 4). Sixteen free flaps were done in total including four paired chimeric and eight single free flaps. Flap recipient sites included knees (n = 5), foot/ankle (n = 3), dorsal hands (n = 2), and thumbs (n = 2). All 16 flaps survived. Five patients had complications: four with major complications requiring operative management and two with minor complications requiring conservative management. Mean follow-up time was 505.7 days (range 115-1564). All lower extremity reconstructions were able to weight-bear at an average of 125.2 days post-injury (range 87-164). CONCLUSIONS: This case series demonstrates that free tissue transfer is a robust option for soft tissue coverage and functional limb salvage in patients with severe frostbite injuries to both upper and lower extremities.

Rethinking Oncologic Facial Nerve Reconstruction in the Acute Phase Through Classification of the Level of Injury.

Early facial nerve reconstruction should be offered in every patient with oncological resections of the facial nerve due to the debilitating functional and psychosocial consequences of facial nerve palsy. Oncologic pathology or oncologic resection accounts for the second most common cause of facial nerve palsy. In the case of these acute injuries, selecting an adequate method for reconstruction to optimize functional and psychosocial well-being is paramount. Authors advocate consideration of the level of injury as a framework for approaching the viable options of reconstruction systematically. Authors breakdown oncologic injuries to the facial nerve in three levels in relation to their nerve reconstruction methods and strategies: Level I (intracranial to intratemporal), Level II (intratemporal to extratemporal and intraparotid), and Level III (extratemporal and extraparotid). Clinical features, common clinical scenarios, donor nerves available, recipient nerve, and reconstruction priorities will be present at each level. Additionally, examples of clinical cases will be shared to illustrate the utility of framing acute facial nerve injuries within injury levels. Selecting donor nerves is critical in successful facial nerve reconstruction in oncological patients. Usually, a combination of facial and nonfacial donor nerves (hybrid) is necessary to achieve maximal reinnervation of the mimetic muscles. Our proposed classification of three levels of facial nerve injuries provides a selection guide, which prioritizes methods for function nerve reconstruction in relation of the injury level in oncologic patients while prioritizing functional outcomes.

Pain Medication Prescribing Patterns in Augmentation Mammoplasty.

Background: The rate of opioid prescribing after low-risk surgical procedures has increased over the past decade, and surgeons are responsible for prescribing approximately one-third of all opioid medications. There is additional supporting evidence that patients only consume about half of the opioids prescribed to them after outpatient plastic surgery. Currently, there is no literature to provide surgeons with reference ranges for how much opioid medication will adequately provide analgesia for patients after undergoing bilateral breast augmentation (BBA) surgery. Objective: To quantify the amount of opioid medication required to adequately control pain for patients after undergoing BBA and use these data to provide recommendations on opioid prescribing practices. Methods: Cross-sectional prospective data were obtained through a take-home medication and pain tracking questionnaire for 56 patients after they underwent either subpectoral or subglandular BBA. Patients documented their pain scores on a 0 to 10 analogue scale and documented the type and amount of pain medication they took for a 7-day period. Results: Our study demonstrated that patients in the subglandular BBA group required an average of either 25 ± 1.2 Tylenol #3 or 19.3 ± 2.3 Tramacet tablets, and the subpectoral group required 27.7 ± 1.7 Tylenol #3 or 25.6 ± 0.9 Tramacet tablets over a 7-day period. There was no statistically significant difference between the 2 surgical groups. Conclusion: We propose a reference range of medication required on average for patients undergoing BBA to obtain adequate pain control in the initial postoperative period that falls within the most recent Canadian guidelines for safe opioid prescribing practices.

Contexte: La fréquence de prescription des opioïdes après des procédures chirurgicales à faible risque a augmenté au cours de la dernière décennie et les chirurgiens sont responsables de la prescription d'environ un tiers de tous les médicaments opioïdes. Des données probantes supplémentaires indiquent que les patients ne consomment qu'environ la moitié des opioïdes qui leur ont été prescrits après une chirurgie plastique en chirurgie de jour. Aucune publication ne procure, à ce jour, des plages de référence aux chirurgiens pour leur indiquer combien d'opioïdes fournira aux patients une analgésie adéquate après avoir subi une chirurgie bilatérale d'augmentation mammaire. Objectif: Quantifier les médicaments opioïdes requis pour contrôler efficacement la douleur chez les patients ayant subi une chirurgie bilatérale d'augmentation mammaire et utiliser ces données pour fournir des recommandations sur les pratiques de prescription des opioïdes. Méthodes: Des données prospectives transversales ont été obtenues au moyen d'un questionnaire à remplir à domicile de suivi des médicaments et de la douleur auprès de 56 patientes venant de subir une chirurgie d'augmentation mammaire sous-pectorale ou sous-glandulaire. Les patientes ont documenté leurs scores de douleur sur une échelle analogique de 0 à 10, ainsi que le type et la quantité de médicament antidouleurs pris pendant une période de 7 jours. Résultats: Notre étude a démontré que les patientes du groupe augmentation mammaire sous glandulaire a nécessité une moyenne de 25 ± 1,2 comprimés de Tylénol #3 ou 19,3 ± 2,3 comprimés de Tramacet; les patientes du groupe sous-pectoral ont nécessité 27,7 ± 1,7 comprimés de Tylénol #3 ou 25,6 ± 0,9 comprimés de Tramacet comprimés sur une période de sept jours. Il n'y a pas eu de différence statistiquement significative entre les deux groupes chirurgicaux. Conclusion: Nous proposons une plage de référence pour les médicaments nécessaires en moyenne pour les patientes subissant une chirurgie d'augmentation mammaire pour contrôler correctement la douleur au cours de la période postopératoire initiale; cette plage de référence correspond aux plus récentes lignes directrices canadiennes sur les pratiques de prescription sécuritaire des opioïdes.

Evaluating glioblastoma tumour sphere growth and migration in interaction with astrocytes using 3D collagen-hyaluronic acid hydrogels.

Glioblastoma (GB) is an astrocytic brain tumour with a low survival rate, partly because of its highly invasive nature. The GB tumour microenvironment (TME) includes its extracellular matrix (ECM), a variety of brain cell types, unique anatomical structures, and local mechanical cues. As such, researchers have attempted to create biomaterials and culture models that mimic features of TME complexity. Hydrogel materials have been particularly popular because they enable 3D cell culture and mimic TME mechanical properites and chemical composition. Here, we used a 3D collagen I-hyaluronic acid hydrogel material to explore interactions between GB cells and astrocytes, the normal cell type from which GB likely derives. We demonstrate three different spheroid culture configurations, including GB multi-spheres (i.e., GB and astrocyte cells in spheroid co-culture), GB-only mono-spheres cultured with astrocyte-conditioned media, and GB-only mono-spheres cultured with dispersed live or fixed astrocytes. Using U87 and LN229 GB cell lines and primary human astrocytes, we investigated material and experiment variability. We then used time-lapse fluorescence microscopy to measure invasive potential by characterizing the sphere size, migration capacity, and weight-averaged migration distance in these hydrogels. Finally, we developed methods to extract RNA for gene expression analysis from cells cultured in hydrogels. U87 and LN229 cells displayed different migration behaviors. U87 migration occurred primarily as single cells and was reduced with higher numbers of astrocytes in both multi-sphere and mono-sphere plus dispersed astrocyte cultures. In contrast, LN229 migration exhibited features of collective migration and was increased in monosphere plus dispersed astrocyte cultures. Gene expression studies indicated that the most differentially expressed genes in these co-cultures were CA9, HLA-DQA1, TMPRSS2, FPR1, OAS2, and KLRD1. Most differentially expressed genes were related to immune response, inflammation, and cytokine signalling, with greater influence on U87 than LN229. These data show that 3D in vitro hydrogel co-culture models can be used to reveal cell line specific differences in migration and to study differential GB-astrocyte crosstalk.

Malignant Peripheral Nerve Sheath Tumors of the Brachial Plexus: A Single-Center Experience on Diagnosis, Management, and Outcomes.

INTRODUCTION: The incidence of malignant peripheral nerve sheath tumors (MPNSTs) is 0.001%. Commonly, MPNST arise in neurofibromatosis; however, they can occur sporadically, de novo or from a preexisting neurofibroma. Malignant peripheral nerve sheath tumors are aggressive tumors with high rates of local recurrence and metastasis. The prognosis is poor with 5-year survival rates of 15% to 50%. Unfortunately, given the rarity of these tumors, it is not clear how to best manage these patients. The purposes of this study were (1) to discuss our experience with MPNST and particularly our difficulties with diagnosis and management, and (2) to review the literature. MATERIALS AND METHODS: We report on all tumors of the brachial plexus excised between 2013 and 2019. We report 3 cases of MPNST, their treatment, and their outcomes. RESULTS: Thirteen patients underwent surgical excision of an intrinsic brachial plexus mass. Three of these patients (2 male, 1 female; average age, 36 years) were diagnosed with an MPNST. Two patients with an MPNST had neurofibromatosis type 1. All patients with an MPNST had a tumor >8 cm, motor and sensory deficits, and pain. All 3 patients with MPNST underwent a magnetic resonance imaging (MRI) before diagnosis. The average time from initial symptom onset to MRI was 12.3 months. Only 1 of the MRIs suggested a malignant tumor, with no MRI identifying an MPNST. One patient underwent an excisional biopsy, and 2 had incisional biopsies. Because of the lack of diagnosis preoperatively, all patients had positive margins given the limited extent of surgery. Returning for excision in an attempt to achieve negative margins in a large oncologically contaminated field was not possible because defining the boundaries of the initial surgical field was unachievable; therefore, the initial surgery was their definitive surgical management. All patients were referred to oncology and received radiation therapy. CONCLUSIONS: Malignant peripheral nerve sheath tumors must be suspected in enlarging masses (>5 cm) with the constellation of pain, motor, and sensory deficits. Computed tomography- or ultrasound-guided core needle biopsy under brachial plexus block or sedation is required for definitive diagnosis to allow for a comprehensive approach to the patient's tumor with a higher likelihood of disease-free survival.

Reversal of apixaban and rivaroxaban with andexanet alfa prior to invasive or surgical procedures.

BACKGROUND: Outcomes following andexanet alfa reversal of factor Xa inhibitors in patients requiring urgent or emergent invasive procedures are lacking. This study aimed to describe efficacy and safety outcomes following andexanet alfa administration within 24 h of an invasive procedure. METHODS: This single-center, observational, retrospective study included patients who received andexanet alfa within 24 h of an invasive or surgical procedure. The primary outcome was hemostatic efficacy graded as excellent, good, or poor using similar definitions to the ANNEXA-4 criteria. Secondary outcomes included hospital discharge disposition, intensive care unit (ICU) and hospital length of stay, 30-day mortality, 30-day thromboischemic event rates, and serum coagulation assay changes pre- and postreversal. RESULTS: Forty-four patients met inclusion criteria; of these, 27 (62.8%) received apixaban and 16 (37.2%) were treated with rivaroxaban prior to admission. The indications for reversal were categorized as intracranial (n = 20 [45.5%]) or extracranial (n = 24 [54.5%]) sites. Majority of patients required emergent operative procedures (18 [40.9%]), followed by invasive device placement (10 [22.7%]) or arterial embolization (9 [20.5%]). Thirty-eight (86.4%) patients were able to be adequately graded for hemostatic efficacy. Overall, 30 (78.9%) patients achieved excellent or good hemostasis within 24 h after periprocedural administration of andexanet alfa (19 [82.6%] apixaban vs. 11 [78.6%] rivaroxaban; 12 [80.0%] intracranial events vs. 18 [78.3%] extracranial events). Discharge disposition was most often to a short- or long-term care facilities (27 [61.4%]). Thirty-day mortality and thromboischemic complications occurred in 15 (34.1%) and 12 (27.3%) patients, respectively. Prothrombin time and antifactor Xa assay results were significantly decreased after andexanet alfa administration (p < 0.05) while thromboelastogram assay values (reaction time, kinetic time, and activated clotting time) showed nonsignificant changes pre- versus postreversal. CONCLUSION: Andexanet alfa may be used for urgent or emergent reversal of apixaban and rivaroxaban peri-procedurally with promising hemostatic outcomes. Further prospective, comparative clinical research is warranted.

Surgical Treatment of Parsonage Turner Syndrome With Primary Nerve Transfers: A Case Series and Cadaver Dissection.

ABSTRACT: Parsonage Turner syndrome (PTS) is the development of severe, spontaneous pain with subsequent nerve palsy. Unfortunately, many patients never achieve full functional recovery, and many have chronic pain. The use of nerve transfers in PTS has not been reported in the literature. We present 4 cases of PTS treated surgically with primary nerve transfer and neurolysis of the affected nerve following the absence of clinical and electrodiagnostic recovery at 5 months from onset. In addition, we present a cadaver dissection demonstrating an interfascicular dissection of the anterior interosseous nerve (AIN) into its components to enable a fascicular transfer in partial AIN neuropathy. Two patients with complete axillary neuropathy underwent a neurorrhaphy between the nerve branch to the lateral head of the triceps and the anterior/middle deltoid nerve branch of the axillary nerve. Two patients with partial AIN neuropathy involving the FDP to the index finger (FDP2) underwent a neurorrhaphy between an extensor carpi radialis brevis nerve branch and the FDP2 nerve branch. All patients had neurolysis of the affected nerves. All subjects recovered at least M4 motor strength. The cadaver dissection demonstrates 3 separate nerve fascicles of the AIN into FPL, FDP2, and pronator quadratus that can be individually selected for reinnervation with a fascicular nerve transfer. Functional recovery for patients with PTS with neurolysis alone is variable. Surgical treatment with neurolysis and a nerve transfer to improve functional recovery when no recovery is seen by 5 months is an option.

One step closer to cancer nanomedicine.

High-throughput tool uncovers links between cell signaling and nanomaterial uptake.

A Novel Silicone Simulation Model for Microvascular Anastomosis.

Purpose: Surgical simulation of microvascular anastomosis has become increasingly popular. There are several living and silicone models available. Current silicone models fail to accurately reproduce a vessel's loose adventitial layer, which may lead to the development of improper microsurgical technique. Our purpose is to create a realistic 3-dimensional microsurgical simulator that incorporates an adventitial vessel layer for higher fidelity manipulation of vessels. Methods: A microvascular anastomosis simulator was manufactured using metal moulds and inorganic materials. Synthetic tubing was created with a metal cylinder, 1.65 mm in diameter, painted with 2 sequential layers of silicon with a shore hardness of 2A. Silicone was allowed to fully cure in-between layers. Vessel adventitia was created with a 100-micron polyester mesh adhered to the silicone vessel exterior. Once dry, the synthetic tube is removed from the metal cylinder is then clipped to reveal the inner lumen. Both Resident and attending physicians evaluated the model with and without the adventitial layer and completed a questionnaire. Results: Grasping and manipulation of the vessel were scored on Average score 4.5 and 3 out of 5, with adventitia and without, respectively (P = .00906). Usefulness as a teaching tool was scored on average 4.9 and 4.2, with adventitia and without, respectively (P = .0232). The analysis included: simulation realism, educational utility, and overall satisfaction. Responses in all domains were favourable, suggesting the utility of this model. Conclusion: We created a realistic, high fidelity microvascular anastomosis simulator that is low cost and easily reproducible. Initial feedback is encouraging regarding realism, educational utility, and overall usefulness. Further validation is required to assess its effectiveness in resident education and skill transfer to the operating room.

Objectif: La simulation chirurgicale de l'anastomose microvasculaire gagne en popularité. Il existe plusieurs modèles de simulation vivants ou en silicone. Les modèles actuels en silicone ne réussissent pas à reproduire la couche adventitielle lâche, ce qui peut entraîner une technique microchirurgicale inappropriée. Les chercheurs voulaient créer un simulateur microchirurgical tridimensionnel réaliste doté d'une couche adventitielle pour manipuler les vaisseaux avec plus de fiabilité. Méthodologie: Les chercheurs ont fabriqué un simulateur d'anastomose microvasculaire au moyen de moules métalliques et de matières inorganiques. Ils ont créé des tubulures synthétiques à l'aide d'un cylindre métallique d'un diamètre de 1,65 mm, qu'ils ont peint de deux couches séquentielles de silicone d'une dureté Shore A de 2. Ils ont laissé le silicone durcir complètement entre les couches et ont créé la couche adventitielle à l'aide d'une maille de polyester de 100 microns fixée à l'extérieur du vaisseau de silicone. Une fois sèche, la tubulure synthétique est retirée du cylindre métallique, puis coupée pour révéler la lumière interne. Des résidents et des médecins traitants ont évalué le modèle avec et sans la couche adventitielle et rempli un questionnaire. Résultats: La saisie et la manipulation du vaisseau ont obtenu un score moyen de 4,5 et de 3 sur 5, avec et sans la couche adventitielle, respectivement (p = 0,00906). L'utilité de ce vaisseau comme outil d'enseignement a obtenu un score moyen de 4,9 et de 4,2, avec et sans la couche adventitielle, respectivement (p = 0,0232). L'analyse incluait le réalisme de la simulation, l'utilité pour l'enseignement et la satisfaction globale. Les réponses étaient favorables dans tous les domaines, ce qui laisse croire à l'utilité du modèle. Conclusion: Les chercheurs ont créé un simulateur d'anastomose microvasculaire haute-fidélité réaliste, à la fois peu coûteux et facile à reproduire. Les premiers commentaires sont encourageants pour ce qui est du réalisme, de l'utilité pour l'enseignement et de l'utilité globale. Son efficacité lors de l'enseignement aux résidents et du transfert du savoir en salle d'opération devra être validée davantage.

The Addition of a Nerve Transfer to the Treatment of Peroneal Neuropathy Secondary to Intraneural Ganglion: Case Series.

ABSTRACT: Peroneal intraneural ganglia are rare, and their management is controversial. Presently, the accepted treatment of intraneural ganglia is decompression and ligation of the articular nerve branch. Although this treatment prevents recurrence of the ganglia, the resultant motor deficit of foot drop in the case of intraneural peroneal ganglia is unsatisfying. Foot drop is classically treated with splinting or tendon transfers to the foot. We have recently published a case report of a peroneal intraneural ganglion treated by transferring a motor nerve branch of flexor hallucis longus into a nerve branch of tibialis anterior muscle in addition to articular nerve branch ligation and decompression of the intraneural ganglion to restore the patient's ability to dorsiflex. We have since performed this procedure on 4 additional patients with appropriate follow-up. Depending on the initial onset of foot drop and time to surgery, nerve transfer from flexor hallucis longus to anterior tibialis nerve branch may be considered as an adjunct to decompression and articular nerve branch ligation for the treatment of symptomatic peroneal intraneural ganglion.

Surgeon-administered Ultrasound-guided Peripheral Nerve Blocks in Outpatient Procedures of the Upper Extremity.

Outpatient hand surgery is often performed in the operating room, which can result in prolonged waiting times for patients when operating room resources are limited. Few studies have explored the application of ultrasound-guided nerve blocks in the setting of outpatient hand surgery. Fifty patients were enrolled in this prospective study. Ultrasound-guided peripheral nerve blocks were performed at the level of the elbow and proximal forearm for outpatient hand surgeries. A timer was used to record the time to administer the block and time to affect. A post-procedure survey was administered, which included a numerical analogue scale (0-10) and Likert rating scale questions to characterize the patients' pain experience for receiving the block and pain during the procedure: pain experienced by patients receiving the ultrasound-guided nerve block(s) (0-10), mean: 1.84; pain experienced by patients during a procedure (0-10), mean: 0.56; surgeon satisfaction during the procedure (0-10), mean 9.78. Average time to perform the ultrasound-guided nerve block(s) was 4 minutes 58 seconds; average time from completion of the block to effect reported by patients, 5 minutes 42 seconds; the average time for performing the procedure, 21 minutes 30 seconds. Our study shows that the use of ultrasound to block peripheral nerves of the forearm is effective; <10% of patients required additional local anesthetic. The technique is safe; no complications were reported. The technique is efficient in an outpatient hand surgery setting.

Comparative Encapsulation Efficiency of Lutein in Micelles Synthesized via Batch and High Throughput Methods.

PURPOSE: Black raspberries (BRBs) and their anthocyanin-rich hydrophilic fractions (BRB-H) have exhibited significant chemopreventative activity across aerodigestive cancers. Lutein, the primary component of the BRB lipophilic fraction (BRB-L), also demonstrates bioactivity potential, but is less well characterized, in part because of its poor, innate bioavailability. For these lipophilic compounds to be accurately evaluated for anticancer efficacy, it is necessary to increase their functional bioavailability using delivery vehicles. Lutein has been delivered in commercial settings in emulsion form. However, emulsions are unstable, particularly in the gastrointestinal tract, which limit their use as an oral nutraceutical. Here, we evaluated lutein encapsulation and cellular uptake for nanoparticle (NP) delivery vehicles composed of three different materials synthesized via two different approaches. METHODS: Specifically, NPs were synthesized via smaller scale batch interfacial instability (II) sonication and semi-continuous high throughput electrohydrodynamic-mediated mixing nanoprecipitation (EM-NP) methods using polystyrene-polyethylene oxide (PSPEO) or polycaprolactone-polyethylene glycol (PCLPEG) block copolymers and PHOSPHOLIPON 90G® (P90G, Lipoid GmbH) lipids. Size distribution, lutein encapsulation efficiency (EE), and cellular uptake and delivery were evaluated for each NP formulation. RESULTS: NPs produced via high throughput EM-NP had higher EEs than NPs produced via batch II sonication, and P90G had the greatest EE (55%) and elicited faster cellular uptake in premalignant oral epithelial cells (SCC83) compared to other delivery systems. CONCLUSION: These qualities suggest P90G could be a beneficial candidate for future lutein in vitro delivery research and clinical translation for oral cancer prevention.

Hyaluronic acid induces ROCK-dependent amoeboid migration in glioblastoma cells.

Glioblastoma (GBM) is the most aggressive and deadly adult brain tumor, primarily because of its high infiltrative capacity and development of resistance to therapy. Although GBM cells are typically believed to migrate via mesenchymal (e.g., fibroblast-like) migration modes, amoeboid (e.g., leucocyte-like) migration modes have been identified and may constitute a salvage pathway. However, the mesenchymal to amoeboid transition (MAT) process in GB is not well characterized, most likely because most culture models induce MAT via pharmacological or genetic inhibition conditions that are far from physiological. In this study, we examined the ability of hyaluronic acid (HA) content in three-dimensional collagen (Col) hydrogels to induce MAT in U87 GBM cells. HA and Col are naturally-occurring components of the brain extracellular matrix (ECM). In pure Col gels, U87 cells displayed primarily mesenchymal behaviors, including elongated cell morphology, clustered actin and integrin expression, and crawling migration behaviors. Whereas an increasing population of cells displaying amoeboid behaviors, including rounded morphology, cortical actin expression, low/no integrin expression, and squeezing or gliding motility, were observed with increasing HA content (0.1-0.2 wt% in Col). Consistent with amoeboid migration, these behaviors were abrogated by ROCK inhibition with the non-specific small molecule inhibitor Y27632. Toward identification of histological MAT classification criteria, we also examined the correlation between cell and nuclear aspect ratio (AR) in Col and Col-HA gels, finding that nuclear AR has a small variance and is not correlated to cell AR in HA-rich gels. These results suggest that HA may regulate GBM cell motility in a ROCK-dependent manner.

MicroRNA-mRNA Interactions at Low Levels of Compressive Solid Stress Implicate mir-548 in Increased Glioblastoma Cell Motility.

Glioblastoma (GBM) is an astrocytic brain tumor with median survival times of <15 months, primarily as a result of high infiltrative potential and development of resistance to therapy (i.e., surgical resection, chemoradiotherapy). A prominent feature of the GBM microenvironment is compressive solid stress (CSS) caused by uninhibited tumor growth within the confined skull. Here, we utilized a mechanical compression model to apply CSS (<115 Pa) to well-characterized LN229 and U251 GBM cell lines and measured their motility, morphology, and transcriptomic response. Whereas both cell lines displayed a peak in migration at 23 Pa, cells displayed differential response to CSS with either minimal (i.e., U251) or large changes in motility (i.e., LN229). Increased migration of LN229 cells was also correlated to increased cell elongation. These changes were tied to epigenetic signaling associated with increased migration and decreases in proliferation predicted via Ingenuity® Pathway Analysis (IPA), characteristics associated with tumor aggressiveness. miRNA-mRNA interaction analysis revealed strong influence of the miR548 family (i.e., mir-548aj, mir-548az, mir-548t) on differential signaling induced by CSS, suggesting potential targets for pharmaceutical intervention that may improve patient outcomes.

Biomolecular detection, tracking, and manipulation using a magnetic nanoparticle-quantum dot platform.

Fluorescent and magnetic materials play a significant role in biosensor technology, enabling sensitive quantification and separations with applications in diagnostics, purification, quality control, and therapeutics. Here, we present a magneto-fluorescent biosensor/separations platform consisting of quantum dots (QDs) and superparamagnetic iron oxide nanoparticles (SPIONs) that are separately encapsulated in amphiphilic block co-polymer micelles conjugated to DNA or protein (i.e., single-stranded (ss) DNA derived from the mRNA of the tumor suppressor protein p53 or avidin protein). Analytes were detected via an aggregation sandwich assay upon binding of at least 1 QD and 1 SPION-containing micelle to result in a fluorescent/magnetic composite. Multiplexed isolation of protein and DNA biomolecules was demonstrated by using QDs of varying emission wavelength; QD fluorescence intensity could be correlated with analyte concentration. Sequential or parallel biomolecule separation was achieved by adding appropriately functionalized SPION-containing micelles and applying user-controlled magnetic fields via patterned magnetic disks and wires. QD fluorescence was used to continuously visualize analyte separation during this process. This QD/SPION platform is simple to use, demonstrates ∼10-16 M sensitivity in analyte detection (comparable to competing QD biosensors based on energy transfer) with specificity against 1 and 2 basepair mismatches in DNA detection, molecular separations capability in solutions of ∼10-10 M, and permits simultaneous or parallel, multiplexed separation of protein and DNA. Thus, this versatile platform enables self-assembly-based rapid, sensitive, and specific detection and separation of biomolecules, simultaneously and with real-time visualization. This technology demonstrates potential for nanoscale assembly, biosensing, and bioseparations.

Pharmacokinetics and Pharmacodynamics of Extended-Infusion Cefepime in Critically Ill Patients Receiving Continuous Renal Replacement Therapy: A Prospective, Open-Label Study.

STUDY OBJECTIVE: To evaluate extended-infusion (EI) cefepime pharmacokinetics (PK) and pharmacodynamic target attainment in critically ill patients receiving continuous venovenous hemofiltration (CVVH) or continuous venovenous hemodialysis (CVVHD). DESIGN: Prospective, open-label, PK study. SETTING: Intensive care units at a large, academic, tertiary-care medical center. PATIENTS: Ten critically ill adults who were receiving cefepime 2 g intravenously every 8 hours as a 4-hour infusion while receiving CVVH (eight patients) or CVVHD (two patients). INTERVENTION: Two sets of five serum cefepime concentrations were collected for each patient to assess pharmacokinetics before and during presumed steady state. Concurrent serum and CRRT effluent samples were collected at hours 1, 2, 3, 4, and 8 after the first cefepime dose and after either the fourth, fifth, or sixth (steady-state) cefepime doses. MEASUREMENTS AND MAIN RESULTS: Reversed-phase high-performance liquid chromatography was used to determine free cefepime concentrations. PK analyses included CRRT clearance, half-life, and sieving coefficient or saturation coefficient. Cefepime peak (4 hrs) concentrations, trough (8 hrs) concentrations (Cmin ), and minimum inhibitory concentration breakpoint of 8 µg/ml for the pathogen (MIC8 ) were used to evaluate attainment of pharmacodynamic targets: 100% of the dosing interval that free drug remains above MIC8 (100% fT > MIC8 ), 100% fT > 4 × MIC8 (optimal), percentage of time fT > 4 × MIC8 (%fT > 4 × MIC8 ) at steady state, and ratio of Cmin to MIC8 (fCmin /MIC8 ). Total CRRT effluent flow rate was a mean ± SD of 30.1 ± 5.4 ml/kg/hr, CRRT clearance was 39.6 ± 9.9 ml/min, and half-life was 5.3 ± 1.7 hours. Sieving coefficient or saturation coefficient were 0.83 ± 0.13 and 0.69 ± 0.22, respectively. First and steady-state dose Cmin were 23.4 ± 10.1 µg/ml and 45.2 ± 14.6 µg/ml, respectively. All patients achieved 100% fT > MIC8 on first and steady-state doses. First and steady-state dose 100% fT > 4 × MIC8 were achieved in 22% (2/9 patients) and 87.5% (7/8 patients) of patients, respectively. The mean %fT > 4 × MIC8 at steady state was 97.5%. The fCmin /MIC8 was 2.92 ± 1.26 for the first dose and 5.65 ± 1.83 at steady state. CONCLUSION: Extended-infusion cefepime dosing in critically ill patients receiving CRRT successfully attained 100% fT > MIC8 in all patients and an appropriate fCmin /MIC8 for both first and steady-state doses. All but one patient achieved 100% fT > 4 × MIC8 at steady state. No significant differences were observed in PK properties between first and steady-state doses among or between patients. It may be reasonable to initiate an empiric or definitive regimen of EI cefepime in critically ill patients receiving concurrent CRRT who are at risk for resistant organisms. Further research is needed to identify the optimal dosing regimen of EI cefepime in this patient population.

Effect of Electrospun Fiber Mat Thickness and Support Method on Cell Morphology.

Electrospun fiber mats (EFMs) are highly versatile biomaterials used in a myriad of biomedical applications. Whereas some facets of EFMs are well studied and can be highly tuned (e.g., pore size, fiber diameter, etc.), other features are under characterized. For example, although substrate mechanics have been explored by several groups, most studies rely on Young's modulus alone as a characterization variable. The influence of fiber mat thickness and the effect of supports are variables that are often not considered when evaluating cell-mechanical response. To assay the role of these features in EFM scaffold design and to improve understanding of scaffold mechanical properties, we designed EFM scaffolds with varying thickness (50-200 µm) and supporting methodologies. EFM scaffolds were comprised of polycaprolactone and were either electrospun directly onto a support, suspended across an annulus (3 or 10 mm inner diameter), or "tension-released" and then suspended across an annulus. Then, single cell spreading (i.e., Feret diameter) was measured in the presence of these different features. Cells were sensitive to EFM thickness and suspended gap diameter. Overall, cell spreading was greatest for 50 µm thick EFMs suspended over a 3 mm gap, which was the smallest thickness and gap investigated. These results are counterintuitive to conventional understanding in mechanobiology, which suggests that stiffer materials, such as thicker, supported EFMs, should elicit greater cell polarization. Additional experiments with 50 µm thick EFMs on polystyrene and polydimethylsiloxane (PDMS) supports demonstrated that cells can "feel" the support underlying the EFM if it is rigid, similar to previous results in hydrogels. These results also suggest that EFM curvature may play a role in cell response, separate from Young's modulus, possibly because of internal tension generated. These parameters are not often considered in EFM design and could improve scaffold performance and ultimately patient outcomes.

Micelle-templated, poly(lactic-co-glycolic acid) nanoparticles for hydrophobic drug delivery.

PURPOSE: Poly(lactic-co-glycolic acid) (PLGA) is widely used for drug delivery because of its biocompatibility, ability to solubilize a wide variety of drugs, and tunable degradation. However, achieving sub-100 nm nanoparticles (NPs), as might be desired for delivery via the enhanced permeability and retention effect, is extremely difficult via typical top-down emulsion approaches. METHODS: Here, we present a bottom-up synthesis method yielding PLGA/block copolymer hybrids (ie, "PolyDots"), consisting of hydrophobic PLGA chains entrapped within self-assembling poly(styrene-b-ethylene oxide) (PS-b-PEO) micelles. RESULTS: PolyDots exhibit average diameters <50 nm and lower polydispersity than conventional PLGA NPs. Drug encapsulation efficiencies of PolyDots match conventional PLGA NPs (ie, ~30%) and are greater than those obtained from PS-b-PEO micelles (ie, ~7%). Increasing the PLGA:PS-b-PEO weight ratio alters the drug release mechanism from chain relaxation to erosion controlled. PolyDots are taken up by model glioma cells via endocytotic mechanisms within 24 hours, providing a potential means for delivery to cytoplasm. PolyDots can be lyophilized with minimal change in morphology and encapsulant functionality, and can be produced at scale using electrospray. CONCLUSION: Encapsulation of PLGA within micelles provides a bottom-up route for the synthesis of sub-100 nm PLGA-based nanocarriers with enhanced stability and drug-loading capacity, and tunable drug release, suitable for potential clinical applications.

Comparing the thoracodorsal and internal mammary vessels as recipients for microsurgical autologous breast reconstruction: A systematic review and meta-analysis.

BACKGROUND: Our aim was to determine whether the thoracodorsal (Td) vessels have comparable clinical outcomes to the internal mammary (IM) vessels as recipients for autologous free tissue transfer for breast reconstruction. METHODS: Systematic searches of MEDLINE, EMBASE, CENTRAL, and World of Science from inception to June 2016 were performed by two independent reviewers. Studies that included adult females undergoing autologous free tissue transfer for breast reconstruction were selected. The two comparison groups were the use of IM or Td as recipient vessels. Our primary outcome was rate of flap survival. We assessed the methodologic quality of included studies using the JADAD and MINOR scales. RESULTS: A total of 1897 patients underwent 2644 free abdominal flap tissue transfer in the 10 articles that were included in our analysis. There was one randomized controlled study (Jadad score 2/5) and 9 nonrandomized controlled studies (MINORS scores 11-19/24). There was no difference between the uses of either vessel in terms of flap loss (1.18; 95% CI 0.71-1.95). Complication rate among the IM vessels ranged from 5 to 12%, compared with 3.4-12% among Td vessels. Hematoma and seroma rates were variable. Fat necrosis was higher with Td vessels in two studies. Performing Td vessels anastomosis was associated with shorter operative time and higher risk of encountering unusable vessel. CONCLUSION: Both recipient vessels are safe, reliable and demonstrate equivocal results in the absence of contraindications. Utilizing either as a first-line vessel is reasonable, depending on surgeons' preference or certain clinical scenarios. QUESTION: Therapeutic, Level of evidence: III.

Automated fluorescent miscroscopic image analysis of PTBP1 expression in glioma.

Multiplexed immunofluorescent testing has not entered into diagnostic neuropathology due to the presence of several technical barriers, amongst which includes autofluorescence. This study presents the implementation of a methodology capable of overcoming the visual challenges of fluorescent microscopy for diagnostic neuropathology by using automated digital image analysis, with long term goal of providing unbiased quantitative analyses of multiplexed biomarkers for solid tissue neuropathology. In this study, we validated PTBP1, a putative biomarker for glioma, and tested the extent to which immunofluorescent microscopy combined with automated and unbiased image analysis would permit the utility of PTBP1 as a biomarker to distinguish diagnostically challenging surgical biopsies. As a paradigm, we utilized second resections from patients diagnosed either with reactive brain changes (pseudoprogression) and recurrent glioblastoma (true progression). Our image analysis workflow was capable of removing background autofluorescence and permitted quantification of DAPI-PTBP1 positive cells. PTBP1-positive nuclei, and the mean intensity value of PTBP1 signal in cells. Traditional pathological interpretation was unable to distinguish between groups due to unacceptably high discordance rates amongst expert neuropathologists. Our data demonstrated that recurrent glioblastoma showed more DAPI-PTBP1 positive cells and a higher mean intensity value of PTBP1 signal compared to resections from second surgeries that showed only reactive gliosis. Our work demonstrates the potential of utilizing automated image analysis to overcome the challenges of implementing fluorescent microscopy in diagnostic neuropathology.