Isaac B. James

Peripheral challenge with double-stranded RNA elicits global up-regulation of cytokine gene expression in the brain.

It is well established that mediators of peripheral inflammation are relayed to the brain and elicit sickness behavior via neuroinflammatory agents that target neuronal substrates. In the present study, we used double‐stranded RNA (dsRNA), a viral replication intermediate, to mimic the acute phase of viral infection. C57BL/6 mice were injected intraperitoneally with 12 mg/kg of synthetic dsRNA, i.e., polyinosinic‐polycytidylic acid (PIC). The treatment induced severe sickness behavior in the animals as revealed by the burrowing test performed 6 hr postinjection. PIC challenge also induced up‐regulation of mRNA for several cytokines in the brain as determined by real‐time quantitative RT‐PCR. In all brain regions, i.e., the forebrain, brainstem, and cerebellum, the gene encoding the CXCL2 chemokine featured the most robust up‐regulation over the basal level (saline‐injected animals), followed by the genes encoding the CCL2 chemokine, interferon‐β (IFNβ), interleukin‐6 (IL‐6), tumor necrosis factor‐α (TNFα), and interleukin‐1β (IL‐1β). The forebrain featured the highest extent of up‐regulation of the Ifnb gene, whereas the other genes attained the highest expression in the cerebellum. Most of the genes featured transient up‐regulation, with peaks occurring 3–6 hr after PIC challenge. The TNFα, CCL2, CXCL2, IFNβ, and IL‐1β messages remained profoundly up‐regulated even at 24 hr. The expression of genes encoding inducible and neuronal nitric oxide synthase (NOS) in the brain was not affected by the peripheral PIC challenge. However, the endothelial NOS message was initially down‐regulated and subsequently up‐regulated, indicating stimulation of cerebral vasculature.

Fat, Stem Cells, and Platelet-Rich Plasma

The ideal filler for aesthetic surgery is inexpensive and easy to obtain, natural in appearance and texture, immunologically compatible, and long lasting without risk of infection. By most metrics, autologous fat grafts meet these criteria perfectly. Although facial fat grafting is now a commonly accepted surgical procedure, there has been a wave of activity applying stem cells and platelet-rich plasma (PRP) therapies to aesthetic practice. This article addresses technical considerations in the use of autologous fat transfer for facial rejuvenation, and also explores the current evidence for these stem cell and PRP therapies in aesthetic practice.

The Architecture of Fat Grafting: What Lies beneath the Surface.

Background: Fat grafting is a powerful procedure limited by unpredictable volume loss. Grafted tissue survives via plasmatic imbibition until neovascularization occurs; therefore, fat that is deposited more than 0.2 cm from capillaries will undergo central necrosis. This study aims to determine the architecture of fat deposits within the recipient bed following fat grafting. Methods: Fat was harvested by liposuction and stained with methylene blue. Stained fat was grafted into 4 × 4 × 2-cm sections of pannus tissue at graft-to-recipient volume ratios ranging from 1:10 to 1:1. Each tissue block was sectioned for stained graft visualization. The diameter of each deposit and the percentage with a radius greater than 0.2 cm were recorded. Results: Average tunnel diameter was 0.20 ± 0.01 cm at a graft-to-recipient ratio of 1:10, 0.25 ± 0.01 cm at 1:8, 0.26 ± 0.01 cm at 1:6, 0.31 ± 0.01 cm at 1:4, 0.40 ± 0.01 cm at 1:2, and 0.57 ± 0.02 cm at 1:1. All comparisons reached statistical significance (p ⩽ 0.05) except 1:8 versus 1:6 (p = 0.96). The percentage of fat parcels with a radius greater than 0.2 cm was 3.0 percent at 1:10, 5.3 percent at 1:8, 9.5 percent at 1:6, 20.9 percent at 1:4, 42.0 percent at 1:2, and 68.3 percent at 1:1. All percentage comparisons were significant except 1:10 versus 1:8 (p = 0.15). Conclusion: As the total volume transferred increases, grafted deposits coalesce to form larger globules, particularly at ratios beyond 1:4, likely contributing to central necrosis and subsequent volume loss. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Improved Estimation of Ultrasound Thermal Strain Using Pulse Inversion Harmonic Imaging

Thermal (temporal) strain imaging (TSI) is being developed to detect the lipid-rich core of atherosclerotic plaques and presence of fatty liver disease. However, the effects of ultrasonic clutter on TSI have not been considered. In this study, we evaluated whether pulse inversion harmonic imaging (PIHI) could be used to improve estimates of thermal (temporal) strain. Using mixed castor oil-gelatin phantoms of different concentrations and artificially introduced clutter, we found that PIHI improved the signal-to-noise ratio of TSI by an average of 213% or 52.1% relative to 3.3- and 6.6-MHz imaging, respectively. In a phantom constructed using human liposuction fat in the presence of clutter, the contrast-to-noise ratio was degraded by 35.1% for PIHI compared with 62.4% and 43.7% for 3.3- and 6.6-MHz imaging, respectively. These findings were further validated using an ex vivo carotid endarterectomy sample. PIHI can be used to improve estimates of thermal (temporal) strain in the presence of clutter.

Long-term Patency of Primary Arterial Repair and the Modified Cold Intolerance Symptom Severity Questionnaire.

Background: The goal of this study was to assess the long-term arterial patency of repaired arteries in the upper extremity and any morbidity resulting from the subsequent occlusion of these vessels. Concurrently, a new questionnaire, the modified Cold Intolerance Symptom Severity (mod CISS) questionnaire, was developed to allow for better assessment of cold intolerance. Methods: Thirteen patients who had undergone repair of the radial (4 patients), ulnar (6 patients), brachial (1 patient), digital (1), and an undefined lower arm artery (1) were examined using questionnaires, physical examination, and high-resolution ultrasound. Results: Outcome measures that were statistically significantly worse in the group of patients who presented with nerve injuries included cold intolerance symptoms, Disabilities of the Arm, Shoulder, and Hand score, Michigan Hand Questionnaire, and grip strength (middle setting on dynamometer). The results from the mod CISS correlated with high statistical significance with the results of the CISS score for the injured hand. Of note, wrist extension was significantly better with patent arteries. Conclusions: Sixty-seven percent of arterial repairs remained patent at 6 years (mean) follow-up. The presence of nerve injury has a higher impact on the outcome metrics assessed in this study than arterial patency. Our modification of the CISS score enhances its utility as a survey of cold intolerance.

Delivery of adipose-derived stem cells in poloxamer hydrogel improves peripheral nerve regeneration: Poloxamer, ASCs, Nerve Repair

Introduction: Peripheral nerve damage is associated with high long‐term morbidity. Because of beneficial secretome, immunomodulatory effects, and ease of clinical translation, transplantation with adipose‐derived stem cells (ASC) represents a promising therapeutic modality. Methods: Effect of ASC delivery in poloxamer hydrogel was assessed in a rat sciatic nerve model of critical‐sized (1.5 cm) peripheral nerve injury. Nerve/muscle unit regeneration was assessed via immunostaining explanted nerve, quantitative polymerase chain reaction (qPCR), and histological analysis of reinnervating gastrocnemius muscle. Results: On the basis of viability data, 10% poloxamer hydrogel was selected for in vivo study. Six weeks after transection and repair, the group treated with poloxamer delivered ASCs demonstrated longest axonal regrowth. The qPCR results indicated that the inclusion of ASCs appeared to result in expression of factors that aid in reinnervating muscle tissue. Discussion: Delivery of ASCs in poloxamer addresses multiple facets of the complexity of nerve/muscle unit regeneration, representing a promising avenue for further study. Muscle Nerve 58: 251–260, 2018

Characteristics and Immunomodulating Functions of Adipose-Derived and Bone Marrow-Derived Mesenchymal Stem Cells Across Defined Human Leukocyte Antigen Barriers

Background Vascularized composite allotransplantation opens new possibilities in reconstructive transplantation such as hand or face transplants. Lifelong immunosuppression and its side-effects are the main drawbacks of this procedure. Mesenchymal stem cells (MSCs) have clinically useful immunomodulatory effects and may be able to reduce the burden of chronic immunosuppression. Herein, we assess and compare characteristics and immunomodulatory capacities of bone marrow- and adipose tissue-derived MSCs isolated from the same human individual across defined human leukocyte antigen (HLA) barriers. Materials and methods Samples of omental (o.) adipose tissue, subcutaneous (s.c.) adipose tissue, and bone marrow aspirate from 10 human organ donors were retrieved and MSCs isolated. Cells were characterized by flow cytometry and differentiated in three lineages: adipogenic, osteogenic, and chondrogenic. In mixed lymphocyte reactions, the ability of adipose-derived mesenchymal stem cells (ASCs) and bone marrow-derived mesenchymal stem cells (BMSCs) to suppress the immune response was assessed and compared within individual donors. HLA mismatched or mitogen stimulations were analyzed in co-culture with different MSC concentrations. Supernatants were analyzed for cytokine contents. Results All cell types, s.c.ASC, o.ASC, and BMSC demonstrated individual differentiation potential and cell surface markers. Immunomodulating effects were dependent on dose and cell passage. Proliferation of responder cells was most effectively suppressed by s.c.ASCs and combination with BMSC resulted in highly efficient immunomodulation. Immunomodulation was not cell contact-dependent and cells demonstrated a specific cytokine secretion. Conclusion When human ASCs and BMSCs are isolated from the same individual, both show effective immunomodulation across defined HLA barriers in vitro. We demonstrate a synergistic effect when cells from the same biologic system were combined. This cell contact-independent function underlines the potential of clinical systemic application of MSCs.

Open Reconstruction of Complex Proximal Metadiaphyseal Fragility Fractures of the Humerus

Purpose: A proactive surgical and rehabilitation protocol was implemented to manage humeral fractures involving both the proximal end and shaft in an older patient population. Primary treatment goals were early return to function and reliable fracture union with minimal complications. Methods: From 2008 to 2012, 21 such operations were performed; 18 were considered “fragility” fractures based on mechanism, patient age, and evidence of osteopenia or osteoporosis. Open reduction and internal fixation (ORIF) was employed using direct reduction and fixation with a long periarticular locking plate. Physiotherapy was commenced 2 weeks postoperatively. The Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire was used to assess functional outcome at a time point greater than 1 year postoperative. Results: The study group consisted primarily of elderly females (83% with a median age of 69 years) whom sustained complex metadiaphyseal proximal humeral fractures after simple mechanical fall (78%). Uneventful union occurred in all cases. Local complications included 1 case of partial radial nerve palsy, which had resolved completely by 1 year. No cases of infection were identified. Long-term return to functionality was evident with a median DASH score of 12 (mean = 21, standard deviation = 20, n = 13). Seventy five percent of patients reported minimal or no pain (question [Q] 24), and 75% achieved return of overhead function (Q6, 12, and 15). Conclusion: Treatment of complex metadiaphyseal fragility fractures with anatomic reduction, fixed angle plating, and early physiotherapy returns the older patient to optimized functionality with minimal risk of complication. The DASH outcomes are equivalent to ORIF of isolated proximal humerus fractures and clinically indistinguishable from the general population.