Anesthesia report card - a customizable tool for performance improvement.

PURPOSE: Measuring and providing performance feedback to physicians has gained momentum not only as a way to comply with regulatory requirements, but also as a way to improve patient care. Measurement of structural, process, and outcome metrics in a reliable, evidence-based, specialty-specific manner maximizes the probability of improving physician performance. The manner in which feedback is provided influences whether the measurement tool will be successful in changing behavior. We created an innovative reporting tool template for anesthesiology practitioners designed to provide detailed, continuous feedback covering many aspects of clinical practice. METHODS: The literature regarding quality metric measurement and feedback strategies was examined to design a reporting tool that could provide high quality information and result in improved performance of clinical and academic tasks. A committee of department leaders and information technology professionals was tasked with determining the measurement criteria and infrastructure needed to generate these reports. Data was collected in a systematic, unbiased manner, and reports were populated with information from multiple databases and software systems. Feedback would be based on frequently updated information and allow for analysis of historical performance as well as comparison amongst peers. RESULTS: A template for an anesthesia report card was created. Categories included compliance, credentialing and qualifications, education, clinical and operating room responsibilities, and academic achievements. Physicians were able to choose to be evaluated in some of the categories and had to meet a minimum number of criteria within each category. This allowed for customization to each practitioner's practice. Criteria were derived from the measures of academic and clinical proficiency, as well as quality metrics. Criteria were objective measures and data gathering was often automated. Reports could be generated that were updated daily and provided historical information, and information about peers in the department and within each subspecialty group. CONCLUSIONS: We demonstrate the creation of an online anesthesia report card that incorporates metrics most likely to engender positive changes in practice and academic responsibilities. This tool provides timely and customized information for each anesthesia practitioner, designed to be easily modifiable to improve the quantity, quality, and substance of metrics being measured. Finally, our tool could serve as a template for a performance measuring tool that can be customizable to a wide variety of practice settings, and upon which both monetary and non-monetary incentives might be based in the future.

Stimulus-triggered fate conversion of somatic cells into pluripotency.

Here we report a unique cellular reprogramming phenomenon, called stimulus-triggered acquisition of pluripotency (STAP), which requires neither nuclear transfer nor the introduction of transcription factors. In STAP, strong external stimuli such as a transient low-pH stressor reprogrammed mammalian somatic cells, resulting in the generation of pluripotent cells. Through real-time imaging of STAP cells derived from purified lymphocytes, as well as gene rearrangement analysis, we found that committed somatic cells give rise to STAP cells by reprogramming rather than selection. STAP cells showed a substantial decrease in DNA methylation in the regulatory regions of pluripotency marker genes. Blastocyst injection showed that STAP cells efficiently contribute to chimaeric embryos and to offspring via germline transmission. We also demonstrate the derivation of robustly expandable pluripotent cell lines from STAP cells. Thus, our findings indicate that epigenetic fate determination of mammalian cells can be markedly converted in a context-dependent manner by strong environmental cues.

Bidirectional developmental potential in reprogrammed cells with acquired pluripotency.

We recently discovered an unexpected phenomenon of somatic cell reprogramming into pluripotent cells by exposure to sublethal stimuli, which we call stimulus-triggered acquisition of pluripotency (STAP). This reprogramming does not require nuclear transfer or genetic manipulation. Here we report that reprogrammed STAP cells, unlike embryonic stem (ES) cells, can contribute to both embryonic and placental tissues, as seen in a blastocyst injection assay. Mouse STAP cells lose the ability to contribute to the placenta as well as trophoblast marker expression on converting into ES-like stem cells by treatment with adrenocorticotropic hormone (ACTH) and leukaemia inhibitory factor (LIF). In contrast, when cultured with Fgf4, STAP cells give rise to proliferative stem cells with enhanced trophoblastic characteristics. Notably, unlike conventional trophoblast stem cells, the Fgf4-induced stem cells from STAP cells contribute to both embryonic and placental tissues in vivo and transform into ES-like cells when cultured with LIF-containing medium. Taken together, the developmental potential of STAP cells, shown by chimaera formation and in vitro cell conversion, indicates that they represent a unique state of pluripotency.

Tissue engineering in the trachea.

This review summarizes efforts to generate an autologous tissue-engineered trachea (TET) using various biomaterial or cell sources to make tracheal cartilage to form the structural components of a functional tracheal replacement. Biomechanical assessments of the TET showed that the cartilage stiffness was excellent in the nude models; however, the sheep autologous TET did not provide sufficient support and collapsed easily. As a result, tissue engineering technology is still far from allowing the functional recovery of patients who suffer from severe tracheal disease. On the other hand, there are several clinical reports seeding cells to decellularized tissue using tissue engineering techniques. However, the working mechanisms of the tissue-engineered trachea remain unclear. Nevertheless, we believe that the field of tissue engineering has great potential for surmounting these obstacles and allowing us to generate functional tracheal replacements in the near future.

Effect on ligament marker expression by direct-contact co-culture of mesenchymal stem cells and anterior cruciate ligament cells.

Ligament and tendon repair is an important topic in orthopedic tissue engineering; however, the cell source for tissue regeneration has been a controversial issue. Until now, scientists have been split between the use of primary ligament fibroblasts or marrow-derived mesenchymal stem cells (MSCs). The objective of this study was to show that a co-culture of anterior cruciate ligament (ACL) cells and MSCs has a beneficial effect on ligament regeneration that is not observed when utilizing either cell source independently. Autologous ACL cells (ACLcs) and MSCs were isolated from Yorkshire pigs, expanded in vitro, and cultured in multiwell plates in varying %ACLcs/%MSCs ratios (100/0, 75/25, 50/50, 25/75, and 0/100) for 2 and 4 weeks. Quantitative mRNA expression analysis and immunofluorescent staining for ligament markers Collagen type I (Collagen-I), Collagen type III (Collagen-III), and Tenascin-C were performed. We show that Collagen-I and Tenascin-C expression is significantly enhanced over time in 50/50 co-cultures of ACLcs and MSCs (p≤0.03), but not in other groups. In addition, Collagen-III expression was significantly greater in MSC-only cultures (p≤0.03), but the Collagen-I-to-Collagen-III ratio in 50% co-culture was closest to native ligament levels. Finally, Tenascin-C expression at 4 weeks was significantly higher (p≤0.02) in ACLcs and 50% co-culture groups compared to all others. Immunofluorescent staining results support our mRNA expression data. Overall, 50/50 co-cultures had the highest Collagen-I and Tenascin-C expression, and the highest Collagen-I-to-Collagen-III ratio. Thus, we conclude that using a 50% co-culture of ACLcs and MSCs, instead of either cell population alone, may better maintain or even enhance ligament marker expression and improve healing.

Isoflurane decreases self-renewal capacity of rat cultured neural stem cells.

BACKGROUND: In models, isoflurane produces neural and behavioral deficits in vitro and in vivo. This study tested the hypothesis that neural stem cells are adversely affected by isoflurane such that it inhibits proliferation and kills these cells. METHODS: Sprague-Dawley rat embryonic neural stem cells were plated onto 96-well plates and treated with isoflurane, 0.7, 1.4, or 2.8%, in 21% oxygen for 6 h and fixed either at the end of treatment or 6 or 24 h later. Control plates received 21% oxygen under identical conditions. Cell proliferation was assessed immunocytochemically using 5-ethynyl-2'-deoxyuridine incorporation and death by propidium iodide staining, lactate dehydrogenase release, and nuclear expression of cleaved caspase 3. Data were analyzed at each concentration using an ANOVA; P < 0.05 was considered significant. RESULTS: Isoflurane did not kill neural stem cells by any measure at any time. Isoflurane, 1.4 and 2.8%, reduced cell proliferation based upon 5-ethynyl-2'-deoxyuridine incorporation, whereas isoflurane, 0.7%, had no effect. At 24 h after treatment, the net effect was a 20-30% decrease in the number of cells in culture. CONCLUSIONS: Isoflurane does not kill neural stem cells in vitro. At concentrations at and above the minimum alveolar concentrations required for general anesthesia (1.4 and 2.8%), isoflurane inhibits proliferation of these cells but has no such effect at a subminimum alveolar concentration (0.7%). These data imply that dosages of isoflurane at and above minimum alveolar concentrations may reduce the pool of neural stem cells in vivo but that lower dosages may be devoid of such effects.

The potential of stem cells in adult tissues representative of the three germ layers.

Mature adult tissues contain stem cells that express many genes normally associated with the early stage of embryonic development, when maintained in appropriate environments. Cells procured from adult tissues representative of the three germ layers (spinal cord, muscle, and lung), each exhibiting the potential to mature into cells representative of all three germ layers. Cells isolated from adult tissues of different germ layer origin were propagated as nonadherent clusters or spheres that were composed of heterogeneous populations of cells. When the clusters or spheres were dissociated, the cells had the ability to reform new, nonadherent spheres for several generations. When implanted in vivo, in association with biodegradable scaffolds, into immunodeficient mice, tissue containing cells characteristic of the three germ layers was generated. These findings suggest the existence of a population of stem cells in adult tissues that is quite different and distinct from embryonic stem cells that demonstrate a greater potency for differentiation across germ lines than previously believed. Such cells could potentially be as useful as embryonic stem cells in tissue engineering and regenerative medicine.

Uncultured marrow mononuclear cells delivered within fibrin glue hydrogels to porous scaffolds enhance bone regeneration within critical-sized rat cranial defects.

For bone tissue engineering, the benefits of incorporating mesenchymal stem cells (MSCs) into porous scaffolds are well established. There is, however, little consensus on the effects of or need for MSC handling ex vivo. Culture and expansion of MSCs adds length and cost, and likely increases risk associated with treatment. We evaluated the effect of using uncultured bone marrow mononuclear cells (bmMNCs) encapsulated within fibrin glue hydrogels and seeded into porous scaffolds to regenerate bone over 12 weeks in an 8-mm-diameter, critical-sized rat cranial defect. A full factorial experimental design was used to evaluate bone formation within model poly(L-lactic acid) and corraline hydroxyapatite scaffolds with or without platelet-rich plasma (PRP) and bmMNCs. Mechanical push-out testing, microcomputed tomographical analyses, and histology were performed. PRP showed no benefit for bone formation. Cell-laden poly(L-lactic acid) scaffolds without PRP required significantly greater force to displace from surrounding tissues than control (cell-free) scaffolds, but no differences were observed during push-out testing of coral scaffolds. For bone volume formation as analyzed by microcomputed tomography, significant positive overall effects were observed with bmMNC incorporation. These data suggest that bmMNCs may provide therapeutic advantages in bone tissue engineering applications without the need for culture, expansion, and purification.

Adult muscle 'stem' cells can be sustained in culture as free-floating myospheres.

The effectiveness of cell-based therapy to treat muscle disease has been hampered by difficulties in isolating, maintaining and propagating the stem cells that are needed for treatment. Here we report the isolation of muscle-derived stem cells from both young and old mice and their propagation over extended periods of time in culture as "free-floating" myospheres. Analysis of these sphere-forming cells showed that they express stem cell antigen-1 (Sca-1), beta1 integrin (CD29), Thy-1 (CD90), and CD34, but did not express CD45, CD31, or myogenic markers (Pax7, Myf5, and MyoD). We found that cells derived from myospheres and then grown adherently (MDACs) behaved similar to primary myoblasts, in that these cells expressed myogenic markers and were able to easily form multinucleated myotubes. Unlike the parental myospheres but analogous to primary myoblasts, MDACs expressed Pax7, Myf5, and MyoD, indicating that the parent myosphere cells were a more primitive type of cell. In support of this we demonstrated that myospheres were also able to differentiate into adipogenic and osteogenic cells in culture, as well as being able to contribute to injured muscle in vivo. In summary, we report that primitive adult muscle stem cells can be easily isolated and sustained in culture as myospheres.

Engineering functional islets from cultured cells.

OBJECTIVE: Although pancreatic islet transplantation can now be performed minimally invasively in patients with type 1 diabetes, the availability of functional islet donors remains the chief obstacle to widespread clinical application. Tissue engineering islet cells in vitro that function when implanted in vivo provides a solution to this problem. RESEARCH DESIGN AND METHODS: Rat pancreatic islets were enzymatically dissociated into a single-cell suspension and seeded onto a polyglycolic acid (PGA) scaffold. The cells were cultured in CMRL 1099 medium containing epidermal growth factor, nerve growth factor, and insulin-like growth factor for 5 days. The PGA and isolated cells were then suspended in a thermoreversible gelatin polymer (TGP) with insulin, transferring and selenous acid, in F-12 and Dulbecco's modified Eagle's medium, to proliferate over a 40-day period. After the degradation of the PGA fibers, the TGP was removed using cold temperature extraction. The tissue-engineered (TE) islets were then collected manually and transplanted beneath the kidney capsule of Streptozotocin (STZ)-induced diabetic nude mice. RESULTS: All mice that received the TE islets reverted from the induced hyperglycemic state to a state of normoglycemia (n = 6). The treated mice demonstrated normal oral glucose tolerance tests. Testing for the species-specific C-peptide allowed discrimination between the exogenous insulin secretions of the TE rat islets and the endogenous secretions of the nude mice. Immunohistochemistry confirmed the multilineage potential of these TE endocrine cells, showing them capable of secreting insulin, glucagon, and somatostatin. CONCLUSIONS: The ability to tissue engineer pancreatic islets in vitro, through use of PGA and TGP, that fully function in vivo to return diabetic-induced mice to state of normoglycemia has potential implications for the treatment type 1 diabetes.

Bioengineered three-layered robust and elastic artery using hemodynamically-equivalent pulsatile bioreactor.

BACKGROUND: There is an essential demand for tissue engineered autologous small-diameter vascular graft, which can function in arterial high pressure and flow circulation. We investigated the potential to engineer a three-layered robust and elastic artery using a novel hemodynamically-equivalent pulsatile bioreactor. METHODS AND RESULTS: Endothelial cells (ECs), smooth muscle cells (SMCs), and fibroblasts were harvested from bovine aorta. A polyglycolic acid (PGA) sheet and a polycaprolactone sheet seeded with SMCs, and a PGA sheet seeded with fibroblast, were wrapped in turn on a 6-mm diameter silicone tube and incubated in culture medium for 30 days. The supporting tube was removed, and the lumen was seeded with ECs and incubated for another 2 days. The pulsatile bioreactor culture, under regulated gradual increase in flow and pressure from 0.2 (0.5/0) L/min and 20 (40/15) mm Hg to 0.6 (1.4/0.2) L/min and 100 (120/80) mm Hg, was performed for an additional 2 weeks (n=10). The engineered vessels acquired distinctly similar appearance and elasticity as native arteries. Scanning electron microscopic examination and Von Willebrand factor staining demonstrated the presence of ECs spread over the lumen. Elastica Van Gieson and Masson Tricrome Stain revealed ample production of elastin and collagen in the engineered grafts. Alpha-SMA and calponin staining showed the presence of SMCs. Tensile tests demonstrated that engineered vessels acquired equivalent ultimate strength and similar elastic characteristics as native arteries (Ultimate Strength of Native: 882+/-133 kPa, Engineered: 827+/-155 kPa, each n=8). CONCLUSIONS: A robust and elastic small-diameter artery was engineered from three types of vascular cells using the physiological pulsatile bioreactor.

Lidocaine inhibits NIH-3T3 cell multiplication by increasing the expression of cyclin-dependent kinase inhibitor 1A (p21).

BACKGROUND: We explored molecular mechanisms by which lidocaine inhibits growth in the murine embryonic fibroblast cell line NIH-3T3. Local anesthetics can adversely affect cell growth in vitro. Their effects on wound healing are controversial. We examined the effects and novel mechanisms by which lidocaine affects in vitro multiplication of the murine fibroblast cell line NIH-3T3. METHODS: NIH-3T3 cells were grown in culture with lidocaine [0, 0.05, 0.5, 1, 2, and 5 mM]. Cell multiplication was assessed by determining cell counts on subsequent days, while mechanisms by which inhibition occurred were evaluated by bromodeoxyuridine uptake, gene expression using polymerase chain reaction array, and Western blot analysis to verify increased levels of affected proteins. RESULTS: Lidocaine caused dose-dependent inhibition of multiplication of NIH-3T3 cells. Effects ranged from no inhibition [0.05 and 0.5 mM] and mild inhibition [1 mM], to severe inhibition [2 and 5 mM] [P = 0.006]. Lidocaine 2 mM inhibited bromodeoxyuridine uptake at day 3.5 [P = 0.02 versus control, and P = 0.0495 vs 1 mM lidocaine]. On day 1.5, lidocaine upregulated expression of cyclin-D1 and cyclin-dependent kinase inhibitor 1A [p21]. On day 2.5, lidocaine increased the levels of p21 protein. CONCLUSIONS: Low concentrations of lidocaine, as would be seen in plasma after spinal, epidural, or plexus anesthesia, do not significantly affect multiplication of fibroblasts. Higher doses of lidocaine arrest cell multiplication at the S-phase of the growth cycle by upregulation of p21, an extremely potent inhibitor of cell multiplication. Higher concentrations, as would be seen after tissue infiltration, severely inhibit fibroblast multiplication and thus may impair wound healing.

Tissue-engineered endothelial and epithelial implants differentially and synergistically regulate airway repair.

The trilaminate vascular architecture provides biochemical regulation and mechanical integrity. Yet regulatory control can be regained after injury without recapitulating tertiary structure. Tissue-engineered (TE) endothelium controls repair even when placed in the perivascular space of injured vessels. It remains unclear from vascular repair studies whether endothelial implants recapitulate the vascular epithelial lining or expose injured tissues to endothelial cells (ECs) with unique healing potential because ECs line the vascular epithelium and the vasa vasorum. We examined this issue in a nonvascular tubular system, asking whether airway repair is controlled by bronchial epithelial cells (EPs) or by ECs of the perfusing bronchial vasculature. Localized bronchial denuding injury damaged epithelium, narrowed bronchial lumen, and led to mesenchymal cell hyperplasia, hypervascularity, and inflammatory cell infiltration. Peribronchial TE constructs embedded with EPs or ECs limited airway injury, although optimum repair was obtained when both cells were present in TE matrices. EC and EP expression of PGE(2), TGFbeta1, TGFbeta2, GM-CSF, IL-8, MCP-1, and soluble VCAM-1 and ICAM-1 was altered by matrix embedding, but expression was altered most significantly when both cells were present simultaneously. EPs may provide for functional control of organ injury and fibrous response, and ECs may provide for preservation of tissue perfusion and the epithelium in particular. Together the two cells optimize functional restoration and healing, suggesting that multiple cells of a tissue contribute to the differentiated biochemical function and repair of a tissue, but need not assume a fixed, ordered architectural relationship, as in intact tissues, to achieve these effects.

Lesión de médula espinal y medicina regenerativa: [revisión] / Spinal cord injury and regenerative medicine: [review]

La lesión medular (LM) es un problema que afecta sobre todo a la población en edad laboral y, por lo tanto, sus repercusiones rebasan el ámbito familiar. La LM es irreversible para la mitad de las víctimas y en la actualidad los tratamientos existentes consisten en la asistencia y la estabilización espinal. Con el reconocimiento de la existencia de células madre (CM), el tratamiento de la LM ha recibido otro enfoque. Las CM se encargan de la renovación de los tejidos durante la vida del individuo y su reparación en caso de lesión. Las CM más atractivas desde el punto de vista terapéutico son las capaces de generar diversos tejidos, obtenibles con facilidad, y cuya manipulación es aceptable en términos éticos. En este artículo se presentan algunos de los estudios realizados con CM de diversos orígenes y su aplicación al tratamiento de la LM.

Spinal cord injury (SCI) is a trauma problem striking mainly working age adults, therefore affecting society beyond the victim’s family circle. Most of the victims of SCI will never recover; therapy for this type of injury consists basically on spinal cord support and stabilization. With the discovery of stem cells (SC), SCI treatment has been given another chance. Stem cells are responsible for tissue renewal throughout the individual’s life, as well as tissue repair when needed. From the therapeutic point of view, the most appealing SC are those capable of generating a variety of tissues, those easily harvested, and finally, those ethically unquestioned. This article summarizes some studies carried with SC of various origins and their application to SCI treatment.

Nanofabrication and microfabrication of functional materials for tissue engineering.

The burgeoning field of regenerative medicine promises significant progress in the treatment of cardiac ischemia, liver disease, and spinal cord injury. Key to its success will be the ability to engineer tissue safely and reliably. Tissue functionality must be recapitulated in the laboratory and then integrated into surrounding tissue upon transfer to the patient. Scaffolding materials must be chosen such that the microenvironment surrounding the cells is a close analog of the native environment. In the early days of tissue engineering, these materials were largely borrowed from other fields, with much of the focus on biocompatibility and biodegradation. However, attention has shifted recently to cell-cell and cell-surface interactions, largely because of enabling technologies at the nanoscale and microscale. Studies on cellular behavior in response to various stimuli are now easily realized by using microfabrication techniques and devices (e.g., biomedical microelectromechanical systems). These experiments are reproducible and moderate in cost, and often can be accomplished at high throughput, providing the fundamental knowledge required to design biomaterials that closely mimic the biological system. It is our opinion that these novel materials and technologies will bring engineered tissues one step closer to practical application in the clinic. This review discusses their application to cardiac, liver, and nerve tissue engineering.

Tissue engineered cartilage "bioshell" protective layer for subcutaneous implants.

OBJECTIVE: One current technique to reconstruct an ear for microtia involves the use of a high density polyethylene auricular implant; however, the implant can extrude if not covered in a temporoparietal fascia flap. Theoretically, an autologous tissue engineered cartilage "bioshell" protective coating around a permanent biocompatible implant might reduce potential extrusion to avoid the flap requirement. We hypothesized that if subjected to intentional exposure, a bioshell coating over an implant would provide enhanced wound healing. METHODS: Six sheets of high density polyethylene and six sheets of 24 carat pure gold wire-mesh measuring 19 mm x 25 mm were implanted subcutaneously in an immunocompetent swine model. Half of each implant group were coated with chondrocytes (50-70 million cells/cm(3)) which were suspended in Pluronic F-127 30% hydrogel; the remaining implants without chondrocytes were used as controls. At 10 weeks post-implantation, partial implant exposure via excision of overlying skin was performed to simulate extrusion and the sites were allowed to heal secondarily. RESULTS: All (6/6) of bioshell implants achieved wound closure after exposure by the seventh post-operative day; controls achieved closure at approximately 10 days. Bioshell neocartilage was evaluated and confirmed histologically using hematoxylin and eosin and safranin O stains. Histochemically, neocartilage approximated native cartilage with 60% glycosaminoglycans content. CONCLUSION: A 'proof-of-principle' tissue engineered bioshell around subcutaneous high density polyethylene and gold implants generated an elastic neocartilage coating, elicited a low inflammatory reaction, and was associated with 30% faster wound healing.