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Some organisms, such as the Mexican axolotl, have the capacity to regenerate complicated biological structures throughout their lives. Which molecular pathways are sufficient to induce a complete endogenous regenerative response in injured tissue is an important question that remains unanswered. Using a gain-of-function regeneration assay, known as the Accessory Limb Model (ALM), we and others have begun to identify the molecular underpinnings of the three essential requirements for limb regeneration; wounding, neurotrophic signaling, and the induction of pattern from cells that retain positional memory. We have previously shown that treatment of Mexican axolotls with exogenous retinoic acid (RA) is sufficient to induce the formation of complete limb structures from blastemas that were generated by deviating a nerve bundle into an anterior-located wound site on the limb. Here we show that these ectopic structures are capable of regenerating and inducing new pattern to form when grafted into new anterior-located wounds. We additionally found that the expression of Alx4 decreases, and Shh expression increases in these anterior located blastemas, but not in the mature anterior tissues, supporting the hypothesis that RA treatment posteriorizes blastema tissue. Based on these and previous observations, we used the ALM assay to test the hypothesis that a complete regenerative response can be generated by treating anterior-located superficial limb wounds with a specific combination of growth factors at defined developmental stages. Our data shows that limb wounds that are first treated with a combination of FGF-2, FGF-8, and BMP-2, followed by RA treatment of the resultant mid-bud stage blastema, will result in the generation of limbs with complete proximal/distal and anterior/posterior limb axes. Thus, the minimal signaling requirements from the nerve and a positional disparity are achieved with the application of this specific combination of signaling molecules.

Left-right (LR) asymmetry is a biologically conserved property in living organisms that can be observed in the asymmetrical arrangement of organs and tissues and in tissue morphogenesis, such as the directional looping of the gastrointestinal tract and heart. The expression of LR asymmetry in embryonic tissues can be appreciated in biased cell alignment. Previously an in vitro chirality assay was reported by patterning multiple cells on microscale defined geometries and quantified the cell phenotype–dependent LR asymmetry, or cell chirality. However, morphology and chirality of individual cells on micropatterned surfaces has not been well characterized. Here, a Python-based algorithm was developed to identify and quantify immunofluorescence stained individual epithelial cells on multicellular patterns. This approach not only produces results similar to the image intensity gradient-based method reported previously, but also can capture properties of single cells such as area and aspect ratio. We also found that cell nuclei exhibited biased alignment. Around 35% cells were misaligned and were typically smaller and less elongated. This new imaging analysis approach is an effective tool for measuring single cell chirality inside multicellular structures and can potentially help unveil biophysical mechanisms underlying cellular chiral bias both in vitro and in vivo.

Intrinsic cell chirality has been implicated in the left-right (LR) asymmetry of embryonic development. Impaired cell chirality could lead to severe birth defects in laterality. Previously, we detected cell chirality with an in vitro micropatterning system. Here, we demonstrate for the first time that chirality can be quantified as the coordination of multiaxial polarization of individual cells and nuclei. Using an object labeling, connected component based method, we characterized cell chirality based on cell and nuclear shape polarization and nuclear positioning of each cell in multicellular patterns of epithelial cells. We found that the cells adopted a LR bias the boundaries by positioning the sharp end towards the leading edge and leaving the nucleus at the rear. This behavior is consistent with the directional migration observed previously on the boundary of micropatterns. Although the nucleus is chirally aligned, it is not strongly biased towards or away from the boundary. As the result of the rear positioning of nuclei, the nuclear positioning has an opposite chirality to that of cell alignment. Overall, our results have revealed deep insights of chiral morphogenesis as the coordination of multiaxial polarization at the cellular and subcellular levels.

The use of pervaporation technology as a green drying process for the recovery and reuse of the solvent, tetrahyrdofuran, in a pharmaceutical synthesis has been evaluated. A case study has been performed on a step in the synthesis of a new oncology drug. Pervaporation has been integrated with a constant-volume distillation process to produce a hybrid system that allows for the recovery and reuse of tetrahydrofuran. An economic and environmental analysis shows that this is an effective technology for this application.

Following central nervous system (CNS) injury, activated astrocytes form glial scars, which inhibit axonal regeneration, leading to long-term functional deficits. Engineered nanoscale scaffolds guide cell growth and enhance regeneration within models of spinal cord injury. However, the effects of micro-/nanosize scaffolds on astrocyte function are not well characterized. In this study, a high throughput (HTP) microscale platform was developed to study astrocyte cell behavior on micropatterned surfaces containing 1 μm spacing grooves with a depth of 250 or 500 nm. Significant changes in cell and nuclear elongation and alignment on patterned surfaces were observed, compared to on flat surfaces. The cytoskeleton components (particularly actin filaments and focal adhesions) and nucleus-centrosome axis were aligned along the grooved direction as well. More interestingly, astrocytes on micropatterned surfaces showed enhanced mitochondrial activity with lysosomes localized at the lamellipodia of the cells, accompanied by enhanced adenosine triphosphate (ATP) release and calcium activities. These data indicate that the lysosome-mediated ATP exocytosis and calcium signaling may play an important role in astrocytic responses to substrate topology. These new findings have furthered our understanding of the biomechanical regulation of astrocyte cell–substrate interactions, and may benefit the optimization of scaffold design for CNS healing.

Information processing deficits are often reported in individuals who have sustained a brain injury. These deficits interfere with the patient's rehabilitation progress because of the brain's inability to efficiently process information. This article describes specific aspects of information processing (i.e. etiology, assessment, rehabilitation). A systematic treatment approach is further discussed using both a controlled group study and a single case design. The results, while tentative, suggest that a systematic approach toward the rehabilitation of information processing deficits was as qualitatively effective, and likely more cost-effective than traditional approaches.

This special issue of Applied Neuropsychology focuses on mild brain injury. This article provides an overview of mild brain injury, including its epidemiology, etiology, diagnostic criteria, and clinical symptoms. The contributing authors discuss various issues related to this topic, and divergent views are presented. Specifically, these include causes, symptoms, assessment, and recovery from mild brain injury. In addition, rehabilitation and forensic aspects of mild brain injury are discussed. Collectively, it is anticipated that this special issue will help to clarify the nature of mild brain injury and stimulate additional interest and research into this phenomenon.

Chirality, or a position bias, is found in many living organisms and has previously been shown to be of critical importance to normal development. Cellular and multicellular observations have begun to show that chirality is indeed found due to unknown mechanisms. To further study this behavior, single C2C12 cells were seeded on rain droplet shaped micropatterns. We hypothesized that this revealed intrinsic characteristics that can be readily determined by image analysis. The droplet shaped patterns allow for easy defining of the polar axis and bias testing. This is an on-going experiment, but preliminary results showed that single cell C2C12 mouse myoblasts have a general preference, with cell nuclei biased in either defined direction (i.e. left or right) and not particularly to one. We propose that single cell micropatterning might be an in vitro tool to study chirality in cells and the mechanisms by which this bias originates.

It has been well-documented that executive function deficits are a common consequence of brain injury. Metacognitive processes, in close alliance with executive functions, are viewed as integral components of learning and awareness. Combining all of these areas may be necessary to achieve a beneficial treatment plan for improving executive functions. This article provides a definitional analysis of executive functions and metacognitive processes and it discusses the role of learning, internal mediation, and strategy development. A specific executive functions program is described and suggested as a framework for establishing a metacognitive-learning routine.

It is well documented that even mild brain injury can manifest with significant cognitive and emotional symptoms. Undoubtedly, these alterations may result in career, social, and personal consequences. In this article we discuss and summarize psychotherapeutic approaches to be used for individuals with mild brain injury. The primary focus is on providing education and assistance for developing coping strategies. Once an individual recognizes, accepts, and adjusts to the limitations resulting from the brain injury, then a more favorable level of adjustment can occur.

Life cycle assessment offers a unique opportunity to analyze emission reductions across all manufacturing sectors. However, few efforts have been made to apply this method to the pharmaceutical industry. Typically, between 80 and 90% of the total mass used in the production of an active pharmaceutical ingredient (API) may be attributed to solvent use. Manufacture of virgin solvent and solvent waste management contribute significantly more life cycle emissions than comparable processes for commodity chemicals, with the majority of this waste consisting of CO2 and other green house gas emissions. Three case studies from Pfizer, Bristol-Myers Squibb, and Novartis are examined. In these cases, solvent recovery and reduction techniques are integrated into API syntheses. It is shown that the actual extent of the environmental footprint reduction can only be realized with a full life cycle analysis.

This case is considered to merit a brief report, mainly for the following reasons which will be further considered in the Discussion: (1) the extent of the sexual deviation and its true nature were not immediately apparent; (2) there has recently been a suggestion that the success of aversion therapy in similar cases may have been in a large measure dependent on a “transference situation”. We think that this case may contribute some evidence to the contrary.