The purpose of this study was to evaluate the impact of an assessment training and certification program on the quality of data collected from clients entering substance abuse treatment. Data were obtained from 15,858 adult and adolescent clients entering 122 treatment sites across the United States using the Global Appraisal of Individual Needs-Initial (GAIN-I). GAIN Administration and Fidelity Index (GAFI) scores were predicted from interviewer certification status, interviewer experience, and their interactions. We controlled for client characteristics expected to lengthen or otherwise complicate interviews. Initial bivariate analyses revealed effects for certification status and experience. A significant interaction between certification and experience indicates interviewers attaining certification and having more experience far outperformed certified interviewers with low experience. Although some client characteristics negatively impacted fidelity, interviewer certification and experience remained salient predictors of fidelity in the multivariate model. The results are discussed with regard to the importance of ongoing monitoring of interviewer skill.

One-fifth of all public treatment admissions are emerging adults, and few studies have considered whether treatments are developmentally appropriate. This study compares outcomes between substance use-disordered adolescents and emerging adults that received the Adolescent Community Reinforcement Approach (A-CRA). Propensity score matching was used to create a weighted comparison group of adolescents (n=151) that had similar demographic characteristics, clinical severity, and treatment retention as the group of emerging adults (n=152). We examined age differences in abstinence and other psychosocial outcomes at the last available follow up. Emerging adults and adolescents both reduced their substance use at follow-up. However, emerging adults were less likely to be abstinent and in remission, and had more days of alcohol use when compared to adolescents. This study’s findings are consistent with prior work on emerging adults. Additional research should examine features of interventions that are most effective in addressing the developmental needs of emerging adults.

Abstract

A high incidence of blast exposure is a 21st century reality in counter-insurgency warfare. However, thresholds for closed-head blast-induced traumatic brain injury (bTBI) remain unknown. Moreover, without objective information about relative blast exposure, warfighters with bTBI may not receive appropriate medical care and may remain in harm's way. Accordingly, we have engineered a blast injury dosimeter (BID) using a photonic crystalline material that changes color following blast exposure. The photonic crystals are fabricated using SU-8 via multi-beam interference laser lithography. The final BID is similar in appearance to an array of small colored stickers that may be affixed to uniforms or helmets in multiple locations. Although durable under normal conditions, the photonic crystalline micro- and nano-structure are precisely altered by blast to create a color change. These BIDs were evaluated using a rat model of bTBI, for which blast shockwave exposure was generated via a compressed air-driven shock tube. With prototype BID arrays affixed to the animals, we found that BID color changes corresponded with subtle brain pathologies, including neuronal degeneration and reactive astrocytosis. These subtle changes were most notable in the dentate gyrus of the hippocampus, cerebral cortex, and cerebellum. These data demonstrate the feasibility of using a materials-based, power-free colorimetric BID as the first self-contained blast sensor calibrated to correspond with brain pathology.

Stroke is a leading cause of morbidity and mortality. While tissue-type plasminogen activator (tPA) remains the only FDA approved treatment for ischemic stroke, clinical use of tPA has been constrained to roughly 3% of eligible patients because of the danger of intracranial hemorrhage and a narrow 3h time window for safe administration. Basic science studies indicate that tPA enhances excitotoxic neuronal cell death. In this review, the beneficial and deleterious effects of tPA in ischemic brain are discussed along with emphasis on development of new approaches towards treatment of patients with acute ischemic stroke. In particular, roles of tPA induced signaling and a novel delivery system for tPA administration based on tPA coupling to carrier red blood cells will be considered as therapeutic modalities for increasing tPA benefit/risk ratio. The concept of the neurovascular unit will be discussed in the context of dynamic relationships between tPA-induced changes in cerebral hemodynamics and histopathologic outcome of CNS ischemia. Additionally, the role of age will be considered since thrombolytic therapy is being increasingly used in the pediatric population, but there are few basic science studies of CNS injury in pediatric animals.

Abstract

Until recently, mild traumatic brain injury (mTBI) or “concussion” was generally ignored as a major health issue. However, emerging evidence suggests that this injury is by no means mild, considering it induces persisting neurocognitive dysfunction in many individuals. Although little is known about the pathophysiological aspects of mTBI, there is growing opinion that diffuse axonal injury (DAI) may play a key role. To explore this possibility, we adapted a model of head rotational acceleration in swine to produce mTBI by scaling the mechanical loading conditions based on available biomechanical data on concussion thresholds in humans. Using these input parameters, head rotational acceleration was induced in either the axial plane (transverse to the brainstem; n=3), causing a 10- to 35-min loss of consciousness, or coronal plane (circumferential to the brainstem; n=2), which did not produce a sustained loss of consciousness. Seven days following injury, immunohistochemical analyses of the brains revealed that both planes of head rotation induced extensive axonal pathology throughout the white matter, characterized as swollen axonal bulbs or varicosities that were immunoreactive for accumulating neurofilament protein. However, the distribution of the axonal pathology was different between planes of head rotation. In particular, more swollen axonal profiles were observed in the brainstems of animals injured in the axial plane, suggesting an anatomic substrate for prolonged loss of consciousness in mTBI. Overall, these data support DAI as an important pathological feature of mTBI, and demonstrate that surprisingly overt axonal pathology may be present, even in cases without a sustained loss of consciousness.

SUMMARY

Chromatin assembly involves the combined action of histone chaperones and ATP-dependent motor proteins. Here we investigate the mechanism of nucleosome assembly with a purified chromatin assembly system containing the histone chaperone NAP1 and the ATP-dependent motor protein ACF. These studies revealed the rapid formation of a stable non-nucleosomal histone-DNA intermediate that is converted into canonical nucleosomes by ACF. The histone-DNA intermediate does not supercoil DNA like a canonical nucleosome, but has a nucleosome-like appearance by atomic force microscopy. This intermediate contains all four core histones, lacks NAP1, and is formed by the initial deposition of histones H3-H4. Conversion of the intermediate into histone H1-containing chromatin results in increased resistance to micrococcal nuclease digestion. These findings suggest that the histone-DNA intermediate corresponds to nascent nucleosome-like structures, such as those observed at DNA replication forks. Related complexes might be formed during other chromatin-directed processes such as transcription, DNA repair, and histone exchange.

Abstract

Previous animal and human studies have demonstrated that chronic treatment with several different antidepressants can stimulate neurogenesis, neural remodeling, and synaptic plasticity in the normal hippocampus. Imipramine is a commonly used tricyclic antidepressant (TCA). We employed a controlled cortical impact (CCI) mouse model of traumatic brain injury (TBI) to assess the effect of imipramine on neurogenesis and cognitive and motor function recovery after TBI. Mice were given daily imipramine injections for either 2 or 4 weeks after injury. Bromodeoxyuridine (BrdU) was administered 3–7 days post-brain injury to label the cells that proliferated as a result of the injury. We assessed the effects of imipramine on post-traumatic motor function using a beam-walk test and an assessment of cognitive function: the novel object recognition test (NOR). Histological analyses were performed at 2 and 4 weeks after CCI. Brain-injured mice treated with imipramine showed significantly improved cognitive function compared to a saline-treated group (p<0.001). However, there was no significant difference in motor function recovery between imipramine-treated and saline-treated mice. Histological examination revealed increased preservation of proliferation of Ki-67- and BrdU-positive cells in the hippocampal dentate gyrus (DG) at 2 and 4 weeks after TBI. Immunofluorescence double-labeling with BrdU and neuron-specific markers at 4 weeks after injury showed that most progenitors became neurons in the DG and astrocytes in the hilus. Notably, treatment with imipramine increased preservation of the total number of newly-generated neurons. Our findings provide direct evidence that imipramine treatment contributes to cognitive improvement after TBI, perhaps by enhanced hippocampal neurogenesis.

Molecular motors drive genome packaging into preformed procapsids in many dsDNA viruses. Here, we present optical tweezers measurements of single DNA molecule packaging in bacteriophage λ. DNA-gpA-gpNu1 complexes were assembled with recombinant gpA and gpNu1 proteins and tethered to microspheres, and procapsids were attached to separate microspheres. DNA binding and initiation of packaging were observed within a few seconds of bringing these microspheres into proximity in the presence of ATP. The motor was observed to generate greater than 50 picoNewtons (pN) of force, in the same range as observed with bacteriophage ϕ29, suggesting that high force generation is a common property of viral packaging motors. However, at low capsid filling the packaging rate averaged ~600 bp/s, which is 3.5-fold higher than ϕ29, and the motor processivity was also 3-fold higher, with less than one slip per genome length translocated. The packaging rate slowed significantly with increasing capsid filling, indicating a buildup of internal force reaching 14 pN at 86% packaging, in good agreement with the force driving DNA ejection measured in osmotic pressure experiments and calculated theoretically. Taken together, these experiments show that the internal force that builds during packaging is largely available to drive subsequent DNA ejection. In addition, we observed an 80 bp/s dip in the average packaging rate at 30% packaging, suggesting that procapsid expansion occurs at this point following the buildup of an average of 4 pN of internal force. In experiments with a DNA construct longer than the wild-type genome, a sudden acceleration in packaging rate was observed above 90% packaging in many cases, and greater than 100% of the genome length was translocated, suggesting that internal force can rupture the immature procapsid.

A major problem hindering the development of autograft alternatives for repairing peripheral nerve injuries is immunogenicity. We have previously shown successful regeneration in transected rat sciatic nerves using conduits filled with allogeneic dorsal root ganglion (DRG) cells without any immunosuppression. In this study, we re-examined the immunogenicity of our DRG neuron implanted conduits as a potential strategy to overcome transplant rejection. A biodegradable NeuraGen® tube was infused with pure DRG neurons or Schwann cells cultured from a rat strain differing from the host rats and used to repair 8 mm gaps in the sciatic nerve. We observed enhanced regeneration with allogeneic cells compared to empty conduits 16 weeks post-surgery, but morphological analyses suggest recovery comparable to the healthy nerves was not achieved. The degree of regeneration was indistinguishable between DRG and Schwann cell allografts although immunogenicity assessments revealed substantially increased presence of Interferon gamma (IFN-γ) in Schwann cell allografts compared to the DRG allografts by two weeks post-surgery. Macrophage infiltration of the regenerated nerve graft in the DRG group 16 weeks post-surgery was below the level of the empty conduit (0.56 fold change from NG; p<0.05) while the Schwann cell group revealed significantly higher counts (1.29 fold change from NG; p<0.001). Major histocompatibility complex I (MHC I) molecules were present in significantly increased levels in the DRG and Schwann cell allograft groups compared to the hollow NG conduit and the Sham healthy nerve. Our results confirmed previous studies that have reported Schwann cells as being immunogenic, likely due to MHC I expression. Nerve gap injuries are difficult to repair; our data suggest that DRG neurons are superior medium to implant inside conduit tubes due to reduced immunogenicity and represent a potential treatment strategy that could be preferable to the current gold standard of autologous nerve transplant.

Blast-induced traumatic brain injury (bTBI) is the “signature wound” of the current wars in Iraq and Afghanistan. However, with no objective information of relative blast exposure, warfighters with bTBI may not receive appropriate medical care and are at risk of being returned to the battlefield. Accordingly, we have created a colorimetric blast injury dosimeter (BID) that exploits material failure of photonic crystals to detect blast exposure. Appearing like a colored sticker, the BID is fabricated in photosensitive polymers via multi-beam interference lithography. Although very stable in the presence of heat, cold or physical impact, sculpted micro- and nano-structures of the BID are physically altered in a precise manner by blast exposure, resulting in color changes that correspond with blast intensity. This approach offers a lightweight, power-free sensor that can be readily interpreted by the naked eye. Importantly, with future refinement this technology may be deployed to identify soldiers exposed to blast at levels suggested to be supra-threshold for non-impact blast-induced mild TBI.

Treatment nonadherence is a leading cause of poor outcomes among populations with bipolar disorder (BD) and is related to subjective experience of illness and treatment. This study examined gender differences in the experience of illness and treatment for those with BD, specifically in regards to treatment adherence. This cross-sectional analysis pooled data from 3 BD studies. A semistructured qualitative instrument, the Subjective Experience of Medication Interview, elicited information on subjective differences in treatment adherence between men and women. Men and women experience comparable levels of stigma and they comparably value lessened irritability and/or impulsivity because of medications. However, men and women differed in fear of weight gain because of medications, value of social support, and self-medication behaviors. Selected differences in subjective illness experience between men and women might be used to inform gender-sensitive approaches to enhance treatment adherence among populations with BD.

Objective

To describe the prevalence, intensity, and functional impact of the following types of pain associated with upper-limb loss: phantom limb, residual limb, back, neck, and nonamputated-limb pain.

Design

Cross-sectional survey; 104 respondents with upper-limb loss at least 6 months postamputation completed measures of pain intensity, interference, disability, and health-related quality-of-life.

Results

Nearly all (90%) of the respondents reported pain, with 76% reporting more than one pain type. Phantom-limb pain and residual-limb pain were the most prevalent (79% and 71%, respectively), followed by back (52%), neck (43%), and nonamputated-limb pain (33%). Although nonamputated-limb pain was least prevalent, it was reported to cause the highest levels of interference and pain-related disability days. Self-reported quality-of-life was significantly lower for individuals with each type of pain compared with those without any pain. Age, time since amputation, and cause of amputation were not associated with pain.

Conclusions

In addition to pain in the phantom and residual limb, back, neck, and nonamputated-limb pain are also common after upper-limb loss. All of these pain types are associated with significant disability and activity interference for some individuals, suggesting that assessment of multiple pain types in persons with upper-limb amputation may be important.

Pain and pain-related interference with physical function have not been thoroughly studied in individuals who have undergone knee-disarticulation amputations. The principal aim of this study was to determine whether individuals with knee-disarticulation amputations have worse pain and pain-related interference with physical function than do individuals with transtibial or transfemoral amputations. We analyzed cross-sectional survey data provided by 42 adults with lower-limb amputations. These individuals consisted of 14 adults reporting knee-disarticulation amputation in one limb and best-matched cases (14 reporting transfemoral amputation and 14 reporting transtibial amputation) from a larger cross-sectional sample of 472 individuals. Participants were rigorously matched based on time since amputation, reason for amputation, age, sex, diabetes diagnosis, and pain before amputation. Continuous outcome variables were analyzed by one-way analysis of variance. Categorical outcomes were analyzed by Pearson chi-square statistic. Given the relatively small sample size and power concerns, mean differences were also described by estimated effect size (Cohen’s d). Of the 42 participants, 83% were male. They ranged in age from 36 to 85 (median = 55.1, standard deviation = 11.0). Most amputations were of traumatic origin (74%), and participants were on average 12.4 years from their amputations at the time of the survey. Individuals with transtibial amputation reported significantly more prosthesis use than did individuals with knee-disarticulation amputation. Amputation levels did not significantly differ in phantom limb pain, residual limb pain, back pain, and pain-related interference with physical function. Estimates of effect size, however, indicated that participants with knee-disarticulation amputation reported less phantom limb pain, phantom limb pain-related interference with physical function, residual limb pain, residual limb pain-related interference with physical function, and back pain-related interference with physical function than did participants with transtibial or transfemoral amputations. This study demonstrated that patients with knee-disarticulation amputation used prostheses significantly less than did patients with transtibial amputation. However, no evidence was found that patients with knee-disarticulation amputation have worse outcomes in terms of pain and pain-related interference with physical function; in fact, they may have more favorable long-term outcomes.

Background

Understanding how kill rates vary among seasons is required to understand predation by vertebrate species living in temperate climates. Unfortunately, kill rates are only rarely estimated during summer.

Methodology/Principal Findings

For several wolf packs in Yellowstone National Park, we used pairs of collared wolves living in the same pack and the double-count method to estimate the probability of attendance (PA) for an individual wolf at a carcass. PA quantifies an important aspect of social foraging behavior (i.e., the cohesiveness of foraging). We used PA to estimate summer kill rates for packs containing GPS-collared wolves between 2004 and 2009. Estimated rates of daily prey acquisition (edible biomass per wolf) decreased from 8.4±0.9 kg (mean ± SE) in May to 4.1±0.4 kg in July. Failure to account for PA would have resulted in underestimating kill rate by 32%. PA was 0.72±0.05 for large ungulate prey and 0.46±0.04 for small ungulate prey. To assess seasonal differences in social foraging behavior, we also evaluated PA during winter for VHF-collared wolves between 1997 and 2009. During winter, PA was 0.95±0.01. PA was not influenced by prey size but was influenced by wolf age and pack size.

Conclusions/Significance

Our results demonstrate that seasonal patterns in the foraging behavior of social carnivores have important implications for understanding their social behavior and estimating kill rates. Synthesizing our findings with previous insights suggests that there is important seasonal variation in how and why social carnivores live in groups. Our findings are also important for applications of GPS collars to estimate kill rates. Specifically, because the factors affecting the PA of social carnivores likely differ between seasons, kill rates estimated through GPS collars should account for seasonal differences in social foraging behavior.

Although virtually ignored in the literature until recently, the process of ‘stretch growth of integrated axon tracts’ is perhaps the most remarkable axon growth mechanism of all. This process can extend axons at seemingly impossible rates without the aid of chemical cues or even growth cones. As animals grow, the organization and extremely rapid expansion of the nervous system appears to be directed purely by mechanical forces on axon tracts. This review provides the first glimpse of the astonishing features of axon tracts undergoing stretch growth and how this natural process can be exploited to facilitate repair of the damaged nervous system.

Object

Although neuron transplantation to repair the nervous system has shown promise in animal models, there are few practical sources of viable neurons for clinical application and insufficient approaches to bridge extensive nerve damage in patients. Therefore, the authors sought a clinically relevant source of neurons that could be engineered into transplantable nervous tissue constructs. The authors chose to evaluate human dorsal root ganglion (DRG) neurons due to their robustness in culture.

Methods

Cervical DRGs were harvested from 16 live patients following elective ganglionectomies, and thoracic DRGs were harvested from 4 organ donor patients. Following harvest, the DRGs were digested in a dispase–collagenase treatment to dissociate neurons for culture. In addition, dissociated human DRG neurons were placed in a specially designed axon expansion chamber that induces continuous mechanical tension on axon fascicles spanning 2 populations of neurons originally plated ~ 100 μm apart.

Results

The adult human DRG neurons, positively identified by neuronal markers, survived at least 3 months in culture while maintaining the ability to generate action potentials. Stretch-growth of axon fascicles in the expansion chamber occurred at the rate of 1 mm/day to a length of 1 cm, creating the first engineered living human nervous tissue constructs.

Conclusions

These data demonstrate the promise of adult human DRG neurons as an alternative transplant material due to their availability, viability, and capacity to be engineered. Also, these data show the feasibility of harvesting DRGs from living patients as a source of neurons for autologous transplant as well as from organ donors to serve as an allograft source of neurons.

There is great concern that one mild traumatic brain injury (mTBI) predisposes individuals to an exacerbated response with a subsequent mTBI. Although no mechanism has been identified, mounting evidence suggests traumatic axonal injury (TAI) plays a role in this process. By using a cell culture system, a threshold of mild TAI was found where dynamic stretch of cortical axons at strains lower than 5% induced no overt pathological changes. However, the axons were found to display an increased expression of sodium channels (NaChs) by 24 hr. After a second, identical mild injury, pathologic increases in [Ca2+]i were observed, leading to axon degeneration. The central role of NaChs in this response was demonstrated by blocking NaChs with tetrodotoxin prior to the second injury, which completely abolished postinjury increases in [Ca2+]i. These data suggest that mild TAI induces a form of sodium channelopathy on axons that greatly exaggerates the pathophysiologic response to subsequent mild injuries.

The risk of traumatic brain injury (TBI) while riding roller coasters has received substantial attention. Case reports of TBI around the time of riding roller coasters have led many medical professionals to assert that the high gravitational forces (G-forces) induced by roller coasters pose a significant TBI risk. Head injury research, however, has shown that G-forces alone cannot predict TBI. Established head injury criterions and procedures were employed to compare the potential of TBI between daily activities and roller coaster riding. Three dimensional head motions were measured during three different roller coaster rides, a pillow fight, and car crash simulations. Data was analyzed and compared to published data using similar analyses of head motions. An 8.05m/s car crash lead to the largest head injury criterion measure (HIC15) of 28.1 and head impact factor (HIP) of 3.41, over six times larger than the roller coaster rides of 4.1 and 0.36. Notably, the linear and rotational components of head acceleration during roller coaster rides were milder than those induced by many common activities. As such, there appears to be an extremely low risk of TBI due to the head motions induced by roller coaster rides.

Background

Cocaine- and amphetamine-regulated transcript (CART) has been demonstrated to play a role in regulating the rewarding and reinforcing effects of various drugs of abuse. A recent study demonstrated that i.c.v. administration of CART negatively modulates reinstatement of alcohol seeking, however, the site(s) of action remains unclear. We investigated the paraventricular thalamus (PVT) as a potential site of relapse-relevant CART signaling, as this region is known to receive dense innervation from CART-containing hypothalamic cells and to project to a number of regions known to be involved in mediating reinstatement, including the nucleus accumbens (NAC), medial prefrontal cortex (mPFC) and basolateral amygdala (BLA).

Methodology/Principal Findings

Male rats were trained to self-administer cocaine before being extinguished to a set criterion. One day following extinction, animals received intra-PVT infusions of saline, tetrodotoxin (TTX; 2.5 ng), CART (0.625 µg or 2.5 µg) or no injection, followed by a cocaine prime (10 mg/kg, i.p.). Animals were then tested under extinction conditions for one hour. Treatment with either TTX or CART resulted in a significant attenuation of drug-seeking behaviour following cocaine-prime, with the 2.5 µg dose of CART having the greatest effect. This effect was specific to the PVT region, as misplaced injections of both TTX and CART resulted in responding that was identical to controls.

Conclusions/Significance

We show for the first time that CART signaling within the PVT acts to inhibit drug-primed reinstatement of cocaine seeking behaviour, presumably by negatively modulating PVT efferents that are important for drug seeking, including the NAC, mPFC and BLA. In this way, we identify a possible target for future pharmacological interventions designed to suppress drug seeking.

Abstract

The purpose of this study was to test the effects of exogenous tissue plasminogen activator (tPA) in traumatic brain injury (TBI). We tested two different tPA formulations, free tPA and tPA bound to erythrocytes (RBC/tPA). Vehicle and each of the tPA treatments were injected intravenously into anesthetized rats 15 min after moderate lateral fluid percussion injury. The animals were sacrificed at 2 days for calculating microclot burden (n = 13) and IgG staining area (n = 13) in the brain sections as indicators of post-traumatic thrombosis and blood–brain barrier (BBB) breakdown, respectively. Another set of injured animals treated in the same way were sacrificed at 7 days to compare cortical lesion volumes (n = 28) and CA3 hippocampal cell loss (n = 24). All evaluations were done blinded with respect to treatment. No significant differences were found with respect to microclot burden or IgG staining volume. Injection of wild-type tPA caused significantly (p < 0.05) larger cortical injuries and greater cerebral hemorrhage. In contrast, there was significantly less cortical injury (p < 0.01) and hippocampal cell loss (p < 0.01) in the RBC/tPA group than in all other groups. These results reveal that RBC/tPA is more neuroprotective in experimental TBI than is unbound tPA.

Background

Previous clinical efficacy trials failed to support the continued development of recombinant gp120 (rgp120) as a candidate HIV vaccine. However, the recent RV144 HIV vaccine trial in Thailand showed that a prime/boost immunization strategy involving priming with canarypox vCP1521 followed by boosting with rgp120 could provide significant, although modest, protection from HIV infection. Based on these results, there is renewed interest in the development of rgp120 based antigens for follow up vaccine trials, where this immunization approach can be applied to other cohorts at high risk for HIV infection. Of particular interest are cohorts in Africa, India, and China that are infected with clade C viruses.

Methodology/Principal Findings

A panel of 10 clade C rgp120 envelope proteins was expressed in 293 cells, purified by immunoaffinity chromatography, and used to immunize guinea pigs. The resulting sera were collected and analyzed in checkerboard experiments for rgp120 binding, V3 peptide binding, and CD4 blocking activity. Virus neutralization studies were carried out with two different assays and two different panels of clade C viruses. A high degree of cross reactivity against clade C and clade B viruses and viral proteins was observed. Most, but not all of the immunogens tested elicited antibodies that neutralized tier 1 clade B viruses, and some sera neutralized multiple clade C viruses. Immunization with rgp120 from the CN97001 strain of HIV appeared to elicit higher cross neutralizing antibody titers than the other antigens tested.

Conclusions/Significance

While all of the clade C antigens tested were immunogenic, some were more effective than others in eliciting virus neutralizing antibodies. Neutralization titers did not correlate with rgp120 binding, V3 peptide binding, or CD4 blocking activity. CN97001 rgp120 elicited the highest level of neutralizing antibodies, and should be considered for further HIV vaccine development studies.

Abstract

Traumatic brain injury (TBI) induces the rapid formation of Alzheimer's disease (AD)-like amyloid-β (AB) plaques in about 30% of patients. However, the mechanisms behind this selective plaque formation are unclear. We investigated a potential association between amyloid deposition acutely after TBI and a genetic polymorphism of the AB-degrading enzyme, neprilysin (n = 81). We found that the length of the GT repeats in AB-accumulators was longer than in non-accumulators. Specifically, there was an increased risk of AB plaques for patients with more than 41 total repeats (p < 0.0001; OR: 10.1). In addition, the presence of 22 repeats in at least one allele was independently associated with plaque deposition (p = 0.03; OR: 5.2). In contrast, the presence of 20 GT repeats in one allele was independently associated with a reduced incidence of AB deposition (p = 0.003). These data suggest a genetically linked mechanism that determines which TBI patients will rapidly form AB plaques. Moreover, these findings provide a potential genetic screening test for individuals at high risk of TBI, such as participants in contact sports and military personnel.

Morphological diversity within closely related species is an essential aspect of evolution and adaptation. Mutations in the Melanocortin 1 receptor (Mc1r) gene contribute to pigmentary diversity in natural populations of fish, birds, and many mammals. However, melanism in the gray wolf, Canis lupus, is caused by a different melanocortin pathway component, the K locus, that encodes a beta-defensin protein that acts as an alternative ligand for Mc1r. We show that the melanistic K locus mutation in North American wolves derives from past hybridization with domestic dogs, has risen to high frequency in forested habitats, and exhibits a molecular signature of positive selection. The same mutation also causes melanism in the coyote, Canis latrans, and in Italian gray wolves, and hence our results demonstrate how traits selected in domesticated species can influence the morphological diversity of their wild relatives.

Although peripheral nerve injury is a common consequence of trauma or surgery, there are insufficient means for repair. In particular, there is a critical need for improved methods to facilitate regeneration of axons across major nerve lesions. Here, we engineered transplantable living nervous tissue constructs to provide a labeled pathway to guide host axonal regeneration. These constructs consisted of stretch-grown, longitudinally aligned living axonal tracts inserted into poly(glycolic acid) tubes. The constructs (allogenic) were transplanted to bridge an excised segment of sciatic nerve in the rat, and histological analyses were performed at 6 and 16 weeks posttransplantation to determine graft survival, integration, and host regeneration. At both time points, the transplanted constructs were found to have maintained their pretransplant geometry, with surviving clusters of graft neuronal somata at the extremities of the constructs spanned by tracts of axons. Throughout the transplanted region, there was an intertwining plexus of host and graft axons, suggesting that the transplanted axons mediated host axonal regeneration across the lesion. By 16 weeks posttransplant, extensive myelination of axons was observed throughout the transplant region. Further, graft neurons had extended axons beyond the margins of the transplanted region, penetrating into the host nerve. Notably, this survival and integration of the allogenic constructs occurred in the absence of immunosuppression therapy. These findings demonstrate the promise of living tissue-engineered axonal constructs to bridge major nerve lesions and promote host regeneration, potentially by providing axon-mediated axonal outgrowth and guidance.

Adoptive cell therapy (ACT) for metastatic melanoma involves the ex vivo expansion and re-infusion of tumor infiltrating lymphocytes (TIL) obtained from resected specimens. With an overall objective response rate of fifty-six percent, this T-cell immunotherapy provides an appealing alternative to other therapies, including conventional therapies with lower response rates. However, there are significant regulatory and logistical concerns associated with the ex vivo activation and large scale expansion of these cells. The best current practice uses a rapid expansion protocol (REP) consisting of an ex vivo process that occurs in tissue culture flasks (T-flasks) and gas-permeable bags, utilizes OKT3 (anti-CD3 monoclonal antibody), recombinant human interleukin-2, and irradiated peripheral blood mononuclear cells to initiate rapid lymphocyte growth. A major limitation to the widespread delivery of therapy to large numbers of melanoma patients is the open system in which a REP is initiated. To address this problem, we have investigated the initiation, expansion and harvest at clinical scale of TIL in a closed-system continuous perfusion bioreactor. Each cell product met all safety criteria for patient treatment and by head-to-head comparison had a similar potency and phenotype as cells grown in control T-flasks and gas-permeable bags. However, the currently available bioreactor cassettes were limited in the total cell numbers that could be generated. This bioreactor may simplify the process of the rapid expansion of TIL under stringent regulatory conditions thereby enabling other institutions to pursue this form of ACT.