Search

Abstract Background Inflammation around cell bodies of primary sensory neurons and retinal ganglion cells enhances expression of neuronal growth-associated genes and stimulates axonal regeneration. We have asked if inflammation would have similar effects on corticospinal neurons, which normally show little response to spinal cord injury. Lipopolysaccharide (LPS) was applied onto the pial surface of the motor cortex of adult rats with or without concomitant injury of the corticospinal tract at C4. Inflammation around corticospinal tract cell bodies in the motor cortex was assessed by immunohistochemistry for OX42 (a microglia and macrophage marker). Expression of growth-associated genes c-jun, ATF3, SCG10 and GAP-43 was investigated by immunohistochemistry or in situ hybridisation. Results Application of LPS induced a gradient of inflammation through the full depth of the motor cortex and promoted c-Jun and SCG10 expression for up to 2 weeks, and GAP-43 upregulation for 3 days by many corticospinal neurons, but had very limited effects on neuronal ATF3 expression. However, many glial cells in the subcortical white matter upregulated ATF3. LPS did not promote sprouting of anterogradely labelled corticospinal axons, which did not grow into or beyond a cervical lesion site. Conclusion Inflammation produced by topical application of LPS promoted increased expression of some growth-associated genes in the cell bodies of corticospinal neurons, but was insufficient to promote regeneration of the corticospinal tract.

Introduction: Ultrasound-guided vascular access is an increasingly popular technique due to its reduced complication and higher success rates. Commercially bought training phantoms allow providers to develop tactile skills in a low-risk setting, but are also expensive and poorly accessible. This study analyzes the efficacy of homemade, low-cost, gelatin-based central line vascular models to teach vascular anatomy and intravascular access techniques in training physicians., Methods: A gelatin mold was created using a mixture of unflavored gelatin, hot water, psyllium husk powder, and rubbing alcohol. Latex tubing, balloons, precooked hot dog, and tofu were inserted to simulate arteries, veins, nerves, and the sternocleidomastoid muscle, respectively. Medical students from a single institution participated in a 90-minute workshop led by interventional radiology residents. Participants completed presurveys and postsurveys that assessed knowledge acquisition and confidence levels related to acquiring central access. All images were obtained using a USB-C Butterfly iQ probe., Results: Twenty medical students were analyzed after the workshop. There was a statistically significant increase in self-reported confidence in basic ultrasound use (adjusting gain, depth, probe manipulation), localizing major anatomical structures, using ultrasound for vessel access, and reported ease in identifying muscle, nerves, and major blood vessels under ultrasound. There was also a significant increase in correctly identified anatomical landmarks after the workshop, including the sternocleidomastoid muscle, internal jugular vein, carotid artery, femoral nerve, femoral artery, and femoral vein., Conclusions: Our findings suggest that our homemade, low-cost, gelatin-based models were effective in teaching vascular anatomy and ultrasound-guided vascular access techniques to training physicians., Competing Interests: The authors declare no conflict of interest., (Copyright © 2023 Society for Simulation in Healthcare.)

Abstract: Sports medicine providers often perform various outpatient procedures to manage musculoskeletal and neuropathic conditions. Vasovagal syncope is a rare but a possible complication. Convulsive syncope is one subtype that involves brief extensor stiffening and nonsustained myoclonus and can be easily mistaken for seizures. We present a case series of convulsive syncope as a complication of common sports medicine outpatient procedures. We aim to describe how to identify this condition, and offer risk stratification and management strategies to mitigate the risks of this complication. Sports medicine providers who routinely practice outpatient procedures should be aware of this complication. Simple changes in approaching the procedure may mitigate these risks. High- and intermediate-risk features of the syncopal episode should prompt physicians to seek further evaluation by a specialist to rule out more serious conditions. In all instances, appropriate on-site support and equipment for emergent resuscitation and management should be prepared., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)

Abstract: Langford, EL, Bergstrom, HC, Lanham, S, Eastman, AQ, Best, S, Ma, X, Mason, MR, and Abel, MG. Evaluation of work efficiency in structural firefighters. J Strength Cond Res 37(12): 2457-2466, 2023-To perform occupational tasks safely and effectively, firefighters (FF) must work quickly and consume air provided by the self-contained breathing apparatus (SCBA) efficiently. However, most literature only factors work rate into performance, neglecting the inherent time limitation imposed by the SCBA. The purpose of this article was to (a) evaluate the reliability and variability in a "work efficiency" (WE) performance metric reflective of both work rate and air consumption; (b) explore the relationship between WE and established measures of metabolic strain; and (c) identify fitness, anthropometric, and demographic correlates of WE. About 79 structural FF completed an air consumption drill while breathing through an SCBA. Self-paced work duration and air consumption were entered into the WE equation. A subsample of FF (n = 44) completed another randomized trial while breathing through a portable gas analyzer. Anthropometric and fitness data were collected separately. Correlations were performed between WE vs. fitness, anthropometric, demographic, and metabolic outcomes. Multiple linear regression was used to identify the strongest predictors of WE. WE was reliable (intraclass correlation coefficient = 0.71) and yielded inter-FF variability {0.79 ± 0.25 ([lb·in-2·min]-1) × 104; coefficient of variation = 31.6%}. WE was positively correlated to oxygen consumption (V̇O2) (L·minute-1, mL·kg-1·minute-1) and tidal volume and negatively correlated to V̇E/V̇O2 and respiratory frequency. Height, upper-body endurance, and aerobic endurance were identified as the strongest predictors of WE (adjusted R2 = 0.59, RMSE = 0.16). WE is a reliable and occupationally relevant method to assess FF performance because it accounts for work rate and air consumption. Firefighters may enhance WE through a training intervention focused on improving metabolic tolerance, upper-body endurance, and aerobic endurance., (Copyright © 2023 National Strength and Conditioning Association.)

Orthopaedic surgery consistently ranks last among all medical specialties in diversity and inclusion. While active efforts have recently been implemented to enact change, no study to date has explored the potential effects that social microaggressions have on an individual's career in orthopaedic surgery. The primary aim of this study was to investigate the influence of the perceived experiences of gender and race-based microaggressions on orthopaedic surgery residents, fellows, and attendings in their decision to pursue a career in orthopaedic surgery., Methods: A 34-question institutional review board-approved, modified version of the validated Racial and Ethnic Minorities Scale and Daily Life Experiences survey was sent to a total of 84 individuals at the University of Miami (UM) Department of Orthopaedics. Responses were anonymously collected from current UM orthopaedic residents, fellows, and attendings. Survey results were analyzed for the prevalence of microaggressions in the context of sex, race, ethnicity, academic goals, daily scenarios, and department support. p-Values less than 0.05 were considered statistically significant., Results: Fifty-four of 84 respondents (64%) completed the survey. Female respondents experienced significantly more gender-based microaggressions than male respondents. On average, male participants disagreed that their experiences with microaggressions made them doubt their ability to pursue a career in orthopaedic surgery while female participants responded they were neutral. In comparison with their White counterparts, non-White and Hispanic ethnicity participants demonstrated a statistically significantly greater frequency of race and ethnicity-based microaggressions., Conclusion: Our study demonstrates that female participants, non-White participants, and Hispanic minorities across all levels of training experience a higher frequency of microaggressions. The impact of these experiences on career decisions and goals for women and persons of color in orthopaedic surgery at this single institution is mixed. Experienced microaggressions should be further investigated as a potential barrier to recruitment and retention of under-represented minorities in orthopaedic surgery., Level of Evidence: III., (Copyright © 2023 The Authors. Published by The Journal of Bone and Joint Surgery, Incorporated. All rights reserved.)

Purpose: To investigate rates of adverse pregnancy events associated with the use of percutaneous nephrostomy tubes (PCN) versus ureteral stents in the treatment of nephrolithiasis during pregnancy., Methods: We queried the TriNetX Diamond Network database to evaluate pregnant women (ICD-10 Z34, O09) with a history of nephrolithiasis (N20-23) who underwent a PCN (CPT 50432) or ureteral stent (52332) placement up to 6 months before delivery (O80-82). We controlled for the following potentially confounding variables through propensity score matching: age, race, ethnicity, acute pyelonephritis (N10), infections of the genitourinary tract in pregnancy (O23.0), and other sepsis (A41) at the time of stent or PCN placement., Results: We identified 2,999 pregnant women who underwent ureteral stent placement and 321 who underwent PCN. Following propensity score matching, we found there to be no significant difference in the rate of premature labor or delivery (aOR 1.08, 95% CI 0.735-1.588), premature rupture of membranes (0.889, 0.453-1.743), intrauterine infection (0.906, 0.379-2.165), or c-Sect. (0.825, 0.408-1.667). Within 6 months of their initial procedure, women with a ureteral stent experienced a significantly decreased rate of subsequent urinary tract infection (UTI) or pyelonephritis (0.52, 0.38-0.71), inpatient hospital stay (0.40, 0.26-0.64), emergency department visit (0.65, 0.48-0.89), and repeat exchange procedure (0.70, 0.51-0.96)., Conclusion: In the treatment of nephrolithiasis during pregnancy, PCN versus ureteral stent placement does not confer a significant difference in rates of adverse pregnancy events. However, ureteral stent placement was associated with a lower incidence of hospital admissions, emergency department visits, exchange procedures, and new UTIs or pyelonephritis., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Abstract: Mason, MR, Heebner, NR, Abt, JP, Bergstrom, HC, Shapiro, R, Langford, EL, and Abel, MG. The acute effect of high-intensity resistance training on subsequent firefighter performance. J Strength Cond Res 37(7): 1507-1514, 2023-High-intensity resistance training (HIRT) is commonly performed by structural firefighters on duty to enhance occupational readiness. However, exercise-induced fatigue may negatively impact subsequent occupational performance. Therefore, the purpose of this study was to assess the acute effect of HIRT on subsequent occupational physical ability in structural firefighters and to determine the time course of recovery. Seven resistance-trained male firefighters performed a timed maximal effort simulated fireground test (SFGT) in 3 randomized conditions: baseline (SFGT baseline ), 10 minutes post HIRT (SFGT 10min ), and 60 minutes post HIRT (SFGT 60min ). Work efficiency and air depletion were assessed during the SFGT. The timed HIRT session consisted of a standardized set of exercises using absolute training loads. Repeated measures analysis of variance and minimal difference (MD) analysis assessed group and individual effects between the conditions, respectively. The level of significance was set at p < 0.05. SFGT 10min completion time was greater than SFGT baseline (430 ± 137 vs. 297 ± 69 seconds, p < 0.01), with no difference between SFGT baseline and SFGT 60min (297 ± 69 vs. 326 ± 89 seconds, p = 0.08). The MD analysis indicated that all firefighters' SFGT 10min times exceeded the MD (±26.4 seconds) compared with SFGT baseline . However, 43% of firefighters still exceeded the MD at SFGT 60min . Air depletion during SFGT 10min was greater than that during SFGT baseline (2,786 ± 488 vs. 2,186 ± 276 lb·in -2 , p = 0.02), with no difference between SFGT baseline and SFGT 60min ( p = 0.25). Work efficiency during SFGT 10min was 40% lower than that during SFGT baseline ( p < 0.01), with no difference between SFGT baseline and SFGT 60min ( p = 0.25). These findings indicate that an acute bout of HIRT decreases multiple descriptors of firefighters' occupational performance 10 minutes post exercise with varied responses at 60 minutes post exercise., (Copyright © 2023 National Strength and Conditioning Association.)

Objectives: To explore pre-doctoral faculty perceptions toward implementation of value-based care (VBC) in didactic and clinical teaching., Methods: This project was a collaborative effort between CareQuest and the University of North Carolina at Chapel Hill, Adams School of Dentistry introducing VBC to pre-doctoral dental faculty as part of a new curriculum. Following a faculty development session on VBC in June 2021, faculty and subject matter experts were invited to participate in qualitative interviews. Subject matter experts were interviewed to establish a baseline for VBC knowledge and understanding. Interviews were recorded and transcribed verbatim. Analysis was conducted by two analysts using ATLAS.ti and a thematic analysis approach., Results: Six faculty and two subject matter experts participated in interviews. Although dental faculty demonstrated some understanding of VBC, they recognized that more training is required to build in-depth knowledge and implementation strategies for teaching dental students. Faculty discussed value-based concepts such as prevention-focused teaching, person-centered care, and disease management over invasive restoration of teeth, and how VBC is bringing about a paradigm shift in dentistry that needs to be reflected in dental education. They acknowledged a disconnect between VBC in didactic teaching versus clinical instruction. Those interviewed believed it would take time to shift faculty mindset and readiness to teach VBC, and continued efforts are needed at the leadership and faculty level for acceptance and implementation., Conclusions: Although dental faculty recognize that VBC can bring a shift in dental practice, more training and guidance to implement it in didactic and clinical teaching is needed., (© 2022 American Dental Education Association.)

Spinal cord injury (SCI) results in a high prevalence of neurogenic obesity and metabolic dysfunction. The increased risk for neurogenic obesity and metabolic dysfunction is mainly due to the loss of energy balance because of significantly reduced energy expenditure following SCI. Consequently, excessive energy intake (positive energy balance) leads to adipose tissue accumulation at a rapid rate, resulting in neurogenic obesity, systemic inflammation, and metabolic dysfunction. The purpose of this article is to review the existing literature on nutrition, dietary intake, and nutrition education in persons with SCI as it relates to metabolic dysfunction. The review will highlight the poor dietary intakes of persons with SCI according to authoritative guidelines and the need for nutrition education for health care professionals and consumers. Nutrition education topics are presented in a module-based format with supporting literature. The authors emphasize the role of a diet consisting of low-energy, nutrient-dense, anti-inflammatory foods consistent with the Dietary Guidelines for Americans' MyPlate to effectively achieve energy balance and reduce the risk for neurogenic obesity and metabolic dysfunction in individuals with SCI.

Introduction: The COVID-19 pandemic response limited access to many traditional forms of physical activity (PA). Purpose:To assess changes in objectively measured PAofUniversity staff during the initial stageofthe COVID-19 pandemic., Methods: We implemented a repeated measures natural experiment design. PA data (walking distance, steps∙d#x2D;1, and Moderate#x2D;to#x2D;Vigorous PA (MVPA) time) from commercial grade triaxial accelerometers were collected from employees (N#x3D;625) of a large, public university in the southeast United States during the months of Jan#x2D;May in calendar years 2019 and 2020., Results: Walking distance (6#x2D;9#x25;, p#x3C;0.001) and steps∙d#x2D;1(7#x2D;11#x25;, p#x3C;0.001) were lower during April and May 2020 compared to 2019. However, MVPA time was not significantly different among calendar years for the months of March#x2D;May. Steps∙d#x2D;1significantly decreased after WHO's worldwide pandemic declaration (10,348#xB1;171 v. 9551#xB1;156 steps∙d#x2D;1, p#x3C;0.001) and campus closure (10,100#xB1;160 v. 9,186#xB1;167 steps∙d#x2D;1, p#x3C;0.001). Conversely, steps∙d#x2D;1significantly increased after implementation of the state's "Healthy at Home" order (9,693#xB1;177 vs. 10,156#xB1;185 steps∙d#x2D;1, p#x3C;0.001)., Conclusion: A decrease in daily steps, but not MVPA, suggests increased sedentary behavior, not reduced participation in exercise, during the early stages of the COVID#x2D;19 pandemic. Specific pandemic response policies may positively or negatively affect PA and sedentary behavior.

Background: The undergraduate program in Public Health of Saint Catherine University is the second most popular major of the institution, drawing students from diverse racial, economic, cultural, and educational backgrounds. This has presented significant opportunities and challenges with regard to providing students and faculty with the needed academic and professional development to ensure graduates embody the skills needed for Public Health workforce of today. The objective of this study was to identify potential structured institutional supports to graduate Public Health professionals from diverse communities to advance health equity. A secondary objective was to determine whether the needed supports for Public Health students might differ from peers in other health programs, specifically Nursing. Methods: Using a mixed methods approach and a convenience sample, data were gathered from Public Health students, nursing students, faculty, and staff from November 2019 through July 2020. The survey assessed stress, grit, and demographic factors. Focus group topics included: academic resilience and professionalism, supports and gaps in the current institutional structure with respect to mitigating student stressors, and opportunities for programmatic solutions. Results: In total, 53 Public Health and 32 in Nursing students completed the survey. Nursing students tended to be farther along in their undergraduate careers, less likely to have failed a class, and more likely to have recently been laid off from a job. Public Health students reported more support from parents, but less support from friends and classmates than their Nursing peers. Most Nursing and Public Health students reported unmanaged stress, and similar average grit scores (3.51 vs. 3.41, p = 0.43), respectively. In focus groups, students described a series of stressors including working full time while attending school, family expectations, difficulty with time management, and learning how to acclimate to college norms. University staff and faculty identified financial pressures as a primary student stressor in addition to complex lives including managing family crises. Conclusions: Study findings are being used to identify or adapt professional development supports in undergraduate Public Health programs. Through supporting a diverse undergraduate student population in Public Health, a future workforce from communities most impacted by health disparities will emerge., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Selameab and Mason.)

Background: Many antimicrobial-resistant infections are community-acquired, yet community carriage of microorganisms by healthy individuals is poorly characterized. We assessed microorganism carriage on the hands of Minnesota State Fair attendees and explored associated factors. Methods: Minnesota State Fair attendees (in 2014) from households with ≥2 members (≥1 member being <19 years old [a child]) were eligible to participate. Participants provided biological samples via a hand plating technique and completed a questionnaire on factors potentially related to microorganism carriage. Using presumptive taxonomic identifications and disk-diffusion-determined resistance phenotypes, hand-culture isolates were classified by microbial type; types were grouped into four broad categories based on inferred pathogenicity and consistency with the skin microbiota. Descriptive statistics, X 2 tests, and generalized linear mixed-effects models were used to explore associations between survey and culture data. Results: We enrolled 206 participants from 82 households during 2 days; 50% of subjects were children. Overall, 99.5% (205/206) of hand samples yielded microorganisms. Most were non-pathogenic, whether skin microbiota (98.5% of participants) or non-skin microbiota (93.2% of participants). Only 2.4% (5/206) of samples yielded antibiotic-resistant bacteria. Children were more likely than adults to carry potentially pathogenic (OR = 3.63, 95% CI: 1.66-7.93) and presumably non-pathogenic (OR = 6.61, 95% CI: 1.67-26.15) non-skin microorganisms. Conclusions: Large community gatherings can serve as efficient sites for estimating the prevalence of microorganism carriage. A small proportion of participants carried antimicrobial-resistant pathogens on their hands; most carried non-pathogenic microorganisms, and no exposures specific to the state fair were associated with microorganism carriage., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2020 Mason, Morawski, Bayliss, Noor, Jama, Clabots and Johnson.)

Purpose: The entrustable professional activity (EPA) framework is an assessment approach used to define the educational outcomes of a program by outlining discrete work tasks learners are expected to perform independently upon graduation. This study outlines the development and evaluation of an EPA framework for predoctoral dental education at the University of North Carolina Adams School of Dentistry., Methods: The draft EPA framework was created in collaboration with a group of faculty members and included 15 statements that were mapped to relevant Commission on Dental Accreditation standards. The draft EPA framework was distributed to faculty via an electronic survey, requesting participants to evaluate whether the EPAs were well-defined; observable; measurable; expected of a general dentist; transferable to other practice settings; and required application of relevant knowledge, skills, and attitudes. In addition, participants were asked to identify the percentage of graduates who could perform these tasks independently and whether learners must be able to perform the list of EPAs upon graduation., Results: Sixty-eight faculty members completed the survey (72% response rate); participants represented all divisions across the school and had extensive dental practice experiences. Overall, participants agreed the EPAs met the defined criteria and were considered important for graduates to be able to demonstrate. Feedback from faculty voiced support for the EPA framework and identified concerns regarding the implementation due to potential faculty calibration and time constraints., Conclusion: Evidence from this study supports additional research to explore how the EPA framework can be further developed in predoctoral and postgraduate dental education programs., (© 2020 American Dental Education Association.)

Since the mid-1980s, service-learning has gained recognition as a pedagogical model in higher education with exciting potential for students' academic, civic, and professional development (1). Deemed a high-impact educational practice by the American Association of Colleges and Universities (AAC&U), extant research points to student learning, engagement, and retention benefits from community-based experiences integrated into curriculum (2, 3). Numerous studies have examined best practices for service-learning from varying stakeholder perspectives (faculty, student, and community partner) and disciplines, however, due to the recent development of public health as a major offering in U.S. undergraduate education, the value of service-learning within the discipline should be further explored. While recommendations for service-learning in undergraduate public health programs have been provided, no evaluation of the impact on student learning outcomes has been conducted (4). This study presents one university's model of service-learning in introductory public health courses, and results from the analysis of two datasets representing students' experience with service-learning in undergraduate public health curriculum. Findings provide empirical support of the effectiveness of this pedagogy for advancing student learning and the achievement of foundational accreditation domains outlined by the Council on Education for Public Health (CEPH).

Methods: The present study aimed to identify patterns and processes in acquisition of oral bacteria and to characterize the microbiota of different dentition states and habitats. Mucosal, salivary, supragingival, and subgingival biofilm samples were collected from orally and systemically healthy children and mother-child dyads in predentate, primary, mixed, and permanent dentitions. 16S rRNA gene sequences were compared to the Human Oral Microbiome Database (HOMD). Functional potential was inferred using PICRUSt., Results: Unweighted and weighted UniFrac distances were significantly smaller between each mother-predentate dyad than infant-unrelated female dyads. Predentate children shared a median of 85% of species-level operational taxonomic units (s-OTUs) and 100% of core s-OTUs with their mothers. Maternal smoking, but not gender, mode of delivery, feeding habits, or type of food discriminated between predentate microbial profiles. The primary dentition demonstrated expanded community membership, structure, and function when compared to the predentate stage, as well as significantly lower similarity between mother-child dyads. The primary dentition also included 85% of predentate core s-OTUs. Subsequent dentitions exhibited over 90% similarity to the primary dentition in phylogenetic and functional structure. Species from the predentate mucosa as well as new microbial assemblages were identified in the primary supragingival and subgingival microbiomes. All individuals shared 65% of species between supragingival and subgingival habitats; however, the salivary microbiome exhibited less than 35% similarity to either habitat., Conclusions: Within the limitations of a cross-sectional study design, we identified two definitive stages in oral bacterial colonization: an early predentate imprinting and a second wave with the eruption of primary teeth. Bacterial acquisition in the oral microbiome is influenced by the maternal microbiome. Personalization begins with the eruption of primary teeth; however, this is limited to phylogeny; functionally, individuals exhibit few differences, suggesting that microbial assembly may follow a defined schematic that is driven by the functional requirements of the ecosystem. This early microbiome forms the foundation upon which newer communities develop as more colonization niches emerge, and expansion of biodiversity is attributable to both introduction of new species and increase in abundance of predentate organisms.

Although physical activity (PA) is associated with decreased risk of chronic diseases, fewer than half of American adults meet the recommendations for daily PA, in part, due to large amounts of sedentary time in the workplace., Purpose: To determine the efficacy of an incentivized workplace PA intervention., Design: Retrospective cohort design., Setting: Large southeastern university., Participants: Of the 16 588 eligible employees working ≥8 h/wk, 6246 (37.6%) participated and 2206 (13.3%) were included in data analysis., Intervention: Six-week PA intervention with tiered incentives (value: $10.50-$29.00)., Measures: Steps/day measured via consumer-grade PA monitors for 1-week pre-, 6-weeks during, and 1-week postintervention., Analysis: Participants were grouped by preintervention PA into 4 groups: <6000 (I); 6000 to 7999 (II); 8000 to 9999 (III); and ≥10 000 (IV) steps/d ( n = 481, 540, 485, and 700, respectively) in accordance with the tiered incentive schedule. Statistical comparisons were made by repeated-measures analysis of variance., Results: During the intervention, participants achieving ≥10 000 steps/d increased by 60%. Groups I, II, and III significantly increased steps/day during the intervention (46%, 24%, and 11%, respectively), which was partially maintained in groups I and II 1-week postintervention. Group IV did not increase steps/day during the intervention and significantly decreased steps/day 1-week postintervention. The estimated cost per participant of this intervention increased with from group I ($55.41) to IV ($71.90)., Conclusion: An incentivized, workplace PA intervention preferentially increases PA and is most cost-effective among university employees with low initial PA who may benefit substantially from increased levels of PA.

Aluminum halide, alkoxide and amide complexes 2-6 of the form (N,N)AlX2-nYn (n = 0, 1 and (N,N) = 1,9-dimesityl-5-phenyldipyrromethene (1)) were synthesized and characterized by NMR spectroscopy and X-ray crystallography. The in situ generated lithium salt of dipyrromethene 1 was reacted with AlX3 to afford aluminum halide complexes (N,N)AlX2 (X = Cl (2), I (3)) which were isolated as dichroic crystals. Salt metathesis reactions were employed to produce alkoxide complexes (N,N)Al(Cl)(O(t)Bu) (4) and (N,N)Al(O(t)Bu)2 (5) from compound 2. The dimethylamide complex (N,N)Al(NMe2)2 (6) was prepared by reaction of dipyrromethene 1 with [Al(NMe2)3]2. Crystallographic data revealed that the dipyrromethene is non-planar when bulky coligands are present as in compounds 3-6, while in the dichloride complex 2 the dipyrromethene is planar. Halide complexes 2 and 3 reacted with adventitious moisture in toluene to afford crystalline acid-base adducts (N,N)H·HX, (X = Cl (7), I (8)), which adopted structures reminiscent of anion receptors. Alkoxide and dimethylamide complexes 5 and 6 were also applied as precatalysts for the ring-opening polymerization of ε-caprolactone and preliminary results are reported.

Background: Leptospirosis is a neglected zoonosis affecting animals and humans caused by infection with Leptospira. The bacteria can survive outside of hosts for long periods of time in soil and water. While identification of Leptospira species from human cases and animal reservoirs are increasingly reported, little is known about the diversity of pathogenic Leptospira species in the environment and how surveillance of the environment might be used for monitoring and controlling disease., Methods and Findings: Water samples (n = 104) were collected from the peri-domestic environment of 422 households from farms, rural villages, and urban slums participating in a broader study on the eco-epidemiology of leptospirosis in the Los Rios Region, Chile, between October 2010 and April 2012. The secY region of samples, previously detected as pathogenic Leptospira by PCR, was amplified and sequenced. Sequences were aligned using ClustalW in MEGA, and a minimum spanning tree was created in PHYLOViZ using the goeBURST algorithm to assess sequence similarity. Sequences from four clinical isolates, 17 rodents, and 20 reference strains were also included in the analysis. Overall, water samples contained L. interrogans, L. kirschneri, and L. weilii, with descending frequency. All species were found in each community type. The distribution of the species differed by the season in which the water samples were obtained. There was no evidence that community-level prevalence of Leptospira in dogs, rodents, or livestock influenced pathogen diversity in the water samples., Conclusions: This study reports the presence of pathogenic Leptospira in the peri-domestic environment of households in three community types and the differences in Leptospira diversity at the community level. Systematic environmental surveillance of Leptospira can be used for detecting changes in pathogen diversity and to identify and monitor contaminated areas where an increased risk of human infection exists.

The regenerative ability of CNS axons decreases with age, however, this ability remains largely intact in PNS axons throughout adulthood. These differences are likely to correspond with age-related silencing of proteins necessary for axon growth and elongation. In previous studies, it has been shown that reintroduction of the α9 integrin subunit (tenascin-C receptor, α9) that is downregulated in adult CNS can improve neurite outgrowth and sensory axon regeneration after a dorsal rhizotomy or a dorsal column crush spinal cord lesion. In the current study, we demonstrate that virally expressed integrins (α9, α6, or β1 integrin) in the adult rat sensorimotor cortex and adult red nucleus are excluded from axons following neuronal transduction. Attempts to stimulate transport by inclusion of a cervical spinal injury and thus an upregulation of extracellular matrix molecules at the lesion site, or cotransduction with its binding partner, β1 integrin, did not induce integrin localization within axons. In contrast, virally expressed α9 integrin in developing rat cortex (postnatal day 5 or 10) demonstrated clear localization of integrins in cortical axons revealed by the presence of integrin in the axons of the corpus callosum and internal capsule, as well as in the neuronal cell body. Furthermore, examination of dorsal root ganglia neurons and retinal ganglion cells demonstrated integrin localization both within peripheral nerve as well as dorsal root axons and within optic nerve axons, respectively. Together, our results suggest a differential ability for in vivo axonal transport of transmembrane proteins dependent on neuronal age and subtype.

The 16S rRNA gene is widely used for taxonomic profiling of microbial ecosystems; and recent advances in sequencing chemistry have allowed extremely large numbers of sequences to be generated from minimal amounts of biological samples. Analysis speed and resolution of data to species-level taxa are two important factors in large-scale explorations of complex microbiomes using 16S sequencing. We present here new software, Phylogenetic Tools for Analysis of Species-level Taxa (PhyloToAST), that completely integrates with the QIIME pipeline to improve analysis speed, reduce primer bias (requiring two sequencing primers), enhance species-level analysis, and add new visualization tools. The code is free and open source, and can be accessed at http://phylotoast.org.

The dorsal column lesion model of spinal cord injury targets sensory fibres which originate from the dorsal root ganglia and ascend in the dorsal funiculus. It has the advantages that fibres can be specifically traced from the sciatic nerve, verifiably complete lesions can be performed of the labelled fibres, and it can be used to study sprouting in the central nervous system from the conditioning lesion effect. However, functional deficits from this type of lesion are mild, making assessment of experimental treatment-induced functional recovery difficult. Here, five functional tests were compared for their sensitivity to functional deficits, and hence their suitability to reliably measure recovery of function after dorsal column injury. We assessed the tape removal test, the rope crossing test, CatWalk gait analysis, and the horizontal ladder, and introduce a new test, the inclined rolling ladder. Animals with dorsal column injuries at C4 or T7 level were compared to sham-operated animals for a duration of eight weeks. As well as comparing groups at individual timepoints we also compared the longitudinal data over the whole time course with linear mixed models (LMMs), and for tests where steps are scored as success/error, using generalized LMMs for binomial data. Although, generally, function recovered to sham levels within 2-6 weeks, in most tests we were able to detect significant deficits with whole time-course comparisons. On the horizontal ladder deficits were detected until 5-6 weeks. With the new inclined rolling ladder functional deficits were somewhat more consistent over the testing period and appeared to last for 6-7 weeks. Of the CatWalk parameters base of support was sensitive to cervical and thoracic lesions while hind-paw print-width was affected by cervical lesion only. The inclined rolling ladder test in combination with the horizontal ladder and the CatWalk may prove useful to monitor functional recovery after experimental treatment in this lesion model.

Peripheral nerve injury results in the activation of a number of transcription factors (TFs) in injured neurons, some of which may be key regulators of the regeneration-associated gene (RAG) programme. Among known RAG TFs, ATF3, Smad1, STAT3 and c-Jun have all been linked to successful axonal regeneration and have known functional and physical interactions. We hypothesised that TF expression would promote regeneration of the central axon branch of DRG neurons in the absence of a peripheral nerve lesion and that simultaneous overexpression of multiple RAG TFs would lead to greater effects than delivery of a single TF. Using adeno-associated viral vectors, we overexpressed either the combination of ATF3, Smad1, STAT3 and c-Jun with farnesylated GFP (fGFP), ATF3 only with fGFP, or fGFP only, in DRG neurons and assessed axonal regeneration after dorsal root transection or dorsal column injury and functional improvement after dorsal root injury. ATF3 alone and the combination of TFs promoted faster regeneration in the injured dorsal root. Surprisingly, however, the combination did not perform better than ATF3 alone. Neither treatment was able to induce functional improvement on sensory tests after dorsal root injury or promote regeneration in a dorsal column injury model. The lack of synergistic effects among these factors indicates that while they do increase the speed of axon growth, there may be functional redundancy between these TFs. Because axon growth is considerably less than that seen after a conditioning lesion, it appears these TFs do not induce the full regeneration programme., (© The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: Despite well-recognized recommendations to reduce human exposure to zoonotic pathogens, the use of personal and herd-level protective practices is inconsistent in communities where human interactions with animals are common. This study assessed household-level participation in rodent- (extermination, proper food storage, trash disposal), occupational- (preventive veterinary care, boot-wearing, glove-wearing), and garden-associated (restricting animal access, boot-wearing, glove-wearing) protective practices in farms, villages, and slums in the Los Rios region, Chile, where zoonotic pathogens are endemic., Methods: Questionnaires administered at 422 households across 12 communities recorded household-level socio-demographic characteristics and participation in nine protective practices. Household inclusion in the analysis of occupational practices required having livestock and a household member with occupational exposure to livestock (n = 127), and inclusion in analysis of garden practices required having a garden and at least one animal (n = 233). The proportion of households participating in each protective practice was compared across community types through chi-square analyses. Mixed effects logistic regression assessed household-level associations between socio-demographic characteristics and participation in each protective practice., Results: Most households (95.3 %) reported participation in rodent control, and a positive association between the number of rodent signs in a household and rodent extermination was observed (OR: 1.75, 95 % CI: 1.41, 2.16). Occupational protective practices were reported in 61.8 % of eligible households; household size (OR: 1.63, 95 % CI: 1.17, 5.84) and having children (OR: 0.22, 95 % CI: 0.06, 0.78) were associated with preventive veterinary care. Among eligible households, 73.8 % engaged in protective practices when gardening, and species diversity was positively associated with wearing boots (OR: 1.27, 95 % CI: 1.03, 1.56). Household-level participation in all three protective practices within any exposure category was limited (<10.4 %) and participation in any individual protective practice varied considerably within and across community types., Conclusions: The levels of participation in protective practices reported in this study are consistent with descriptions in the literature of imperfect use of methods that reduce human exposure to zoonotic pathogens. The wide differences across communities in the proportion of households participating in protective practices against human exposure to zoonotic pathogens, suggests that future research should identify community-level characteristics that influence household participation in such practices.

The existence of symbiotic relationships between bacteria and their hosts in various ecosystems have long been known to science. The human body also hosts vast numbers of bacteria in several habitats. Emerging evidence from the gastro-intestinal tract, genito-urinary tract and respiratory indicates that there are several health benefits to hosting a complex and diverse microbial community. Bacteria colonize the oral cavity within a few minutes after birth and form stable communities. Our knowledge of the oral microbiome has expanded exponentially with development of novel exploratory methods that allow us to examine diversity, structure, function, and topography without the need to cultivate the individual components of the biofilm. The purpose of this perspective, therefore, is to examine the strength of current evidence supporting a role for the oral microbiome in maintaining oral health. While several lines of evidence are emerging to suggest that indigenous oral microbiota may have a role in immune education and preventing pathogen expansion, much more work is needed to definitively establish whether oral bacteria do indeed contribute to sustaining oral health, and if so, the mechanisms underlying this role.

Dysbiotic oral bacterial communities have a critical role in the etiology and progression of periodontal diseases. The goal of this study was to investigate the extent to which smoking increases risk for disease by influencing the composition of the subgingival microbiome in states of clinical health. Subgingival plaque samples were collected from 200 systemically and periodontally healthy smokers and nonsmokers. 16S pyrotag sequencing was preformed generating 1,623,713 classifiable sequences, which were compared with a curated version of the Greengenes database using the quantitative insights into microbial ecology pipeline. The subgingival microbial profiles of smokers and never-smokers were different at all taxonomic levels, and principal coordinate analysis revealed distinct clustering of the microbial communities based on smoking status. Smokers demonstrated a highly diverse, pathogen-rich, commensal-poor, anaerobic microbiome that is more closely aligned with a disease-associated community in clinically healthy individuals, suggesting that it creates an at-risk-for-harm environment that is primed for a future ecological catastrophe.

Leptospirosis is a zoonosis of global distribution that affects tropical and temperate areas. Under suitable conditions, Leptospira can survive in water and soil and contribute to human and animal infections. The objective of this study was to describe the presence of pathogenic Leptospira in peri-domestic water samples from rural households in southern Chile. Water samples, including puddles, containers, animal troughs, rivers, canals, and drinking water were collected from 236 households and tested for Leptospira using a PCR assay targeting the lipL32 gene. Evidence of Leptospira presence was detected in all sample types; overall, 13.5% (77/570) samples tested positive. A total of 10/22 (45.5%) open containers, 12/83 (14.5%) animal drinking sources, 9/47 (19.1%) human drinking sources, and 36/306 (19.3%) puddles tested positive. Lower income (OR = 4.35, p = 0.003), increased temperature (OR = 1.23, p < 0.001), and presence of dogs (OR = 15.9, p = 0.022) were positively associated with positive puddles. Increased number of rodent signs was associated with positive puddles in the household (OR = 3.22); however, only in the lower income households. There was no association between PCR positive rodents and puddles at the household level. Results revealed the ubiquity of Leptospira in the household environment and highlight the need to develop formal approaches for systematic monitoring.

Adeno-associated viral (AAV) vectors based on serotype 5 are an efficient means to target dorsal root ganglia (DRG) to study gene function in the primary sensory neurons of the peripheral nervous system. In this study, we have developed a compact AAV dual promoter vector composed of the cytomegalovirus (CMV) and chicken beta-actin (CAG) promoters in a back-to-back configuration with a shared enhancer, and show efficient expression of two proteins simultaneously in DRG neurons. We demonstrate how this is useful for experiments on axonal regeneration, by co-expressing a gene of interest and an axonal marker. Using a farnesylated form of eGFP, which is actively transported along axons, we show superior long-distance labelling of axons of DRG neurons compared with normal eGFP. Additionally, we have efficiently transduced lumbar DRG neurons by injecting the AAV dual promoter vector into the dorsal intrathecal space, which is a less invasive delivery method. In summary, we have developed an AAV dual promoter vector designed for simultaneous expression of a gene of interest and a fluorescent protein to label long-distance axonal projections, which allows specific quantification of axons from transduced neurons after injury.

Oral infections have a strong ethnic predilection; suggesting that ethnicity is a critical determinant of oral microbial colonization. Dental plaque and saliva samples from 192 subjects belonging to four major ethnicities in the United States were analyzed using terminal restriction fragment length polymorphism (t-RFLP) and 16S pyrosequencing. Ethnicity-specific clustering of microbial communities was apparent in saliva and subgingival biofilms, and a machine-learning classifier was capable of identifying an individual's ethnicity from subgingival microbial signatures. The classifier identified African Americans with a 100% sensitivity and 74% specificity and Caucasians with a 50% sensitivity and 91% specificity. The data demonstrates a significant association between ethnic affiliation and the composition of the oral microbiome; to the extent that these microbial signatures appear to be capable of discriminating between ethnicities.

Aim: Although it is established that peri-implantitis is a bacterially induced disease, little is known about the bacterial profile of peri-implant communities in health and disease. The purpose of the present investigation was to examine the microbial signatures of the peri-implant microbiome in health and disease., Materials and Methods: Subgingival and submucosal plaque samples were collected from forty subjects with periodontitis, peri-implantitis, periodontal and peri-implant health and analysed using 16S pyrosequencing., Results: Peri-implant biofilms demonstrated significantly lower diversity than subgingival biofilms in both health and disease, however, several species, including previously unsuspected and unknown organisms, were unique to this niche. The predominant species in peri-implant communities belonged to the genera Butyrivibrio, Campylobacter, Eubacterium, Prevotella, Selenomonas, Streptococcus, Actinomyces, Leptotrichia, Propionibacterium, Peptococcus, Lactococcus and Treponema. Peri-implant disease was associated with lower levels of Prevotella and Leptotrichia and higher levels of Actinomyces, Peptococcus, Campylobacter, non-mutans Streptococcus, Butyrivibrio and Streptococcus mutans than healthy implants. These communities also demonstrated lower levels of Prevotella, non-mutans Streptococcus, Lactobacillus, Selenomonas, Leptotrichia, Actinomyces and higher levels of Peptococcus, Mycoplasma, Eubacterium, Campylobacter, Butyrivibrio, S. mutans and Treponema when compared to periodontitis-associated biofilms., Conclusion: The peri-implant microbiome differs significantly from the periodontal community in both health and disease. Peri-implantitis is a microbially heterogeneous infection with predominantly gram-negative species, and is less complex than periodontitis., (© 2012 John Wiley & Sons A/S.)

Addition of tert-butylisocyanide or 2,6-dimethylphenylisocyanide to a solution of trialkylaluminum or trialkylgallium results in formation of complexes R(3)M·C≡N(t)Bu (M = Al, R = Me (1), Et (2), (i)Bu (3), (t)Bu (4); M = Ga, R = (t)Bu (9)) or R(3)M·C≡N(2,6-Me(2)C(6)H(3)) (M = Al, R = Me (5), Et (6), (i)Bu (7), (t)Bu (8); M = Ga, R = (t)Bu (10)), respectively. Complexes 1, 4, 5, and 8-10 are isolated as solids, whereas the triethylaluminum and triisobutylaluminum adducts 2, 3, 6, and 7 are viscous oils. Complexes 1-10 were characterized by NMR ((1)H, (13)C) and IR spectroscopies, and the molecular structures of 4, 5, and 8-10 were also determined by X-ray crystallography. The frequency of the C≡N stretch of the isocyanide increased by 58-91 cm(-1) upon complexation, consistent with coordination of the isocyanide as a σ donor. Enthalpies of complex formation for 1-10 were determined by isothermal titration calorimetry. Enthalpy data suggest the following order of decreasing Lewis acidity: (t)Bu(3)Al ≫ (i)Bu(3)Al ≥ Me(3)Al ≈ Et(3)Al ≫ (t)Bu(3)Ga. In the absence of oxygen and protic reagents, the reported complexes do not undergo insertion or elimination reactions upon heating their benzene-d(6) solutions to 80 °C.

A comprehensive understanding of the molecular pathways activated by traumatic neural injury is of major importance for the development of treatments for spinal cord injury (SCI). High-throughput gene expression profiling is a powerful approach to reveal genome-wide changes in gene expression during a specific biological process. Microarray analysis of injured nerves or neurons would ideally generate new hypotheses concerning the progression or deregulation of injury- and repair-related biological processes, such as neural scar formation and axon regeneration. These hypotheses should subsequently be tested experimentally and would eventually provide the molecular substrates for the development of novel therapeutics. Over the last decade, this approach has elucidated numerous extrinsic (mostly neural scar-associated) as well as neuron-intrinsic genes that are regulated following an injury. To date, the main challenge is to translate the observed injury-induced gene expression changes into a mechanistic framework to understand their functional implications. To achieve this, research on neural repair will have to adopt the conceptual advances and analytical tools provided by the functional genomics and systems biology revolution. Based on progress made in bioinformatics, high-throughput and high-content functional cellular screening, and in vivo gene transfer technology, we propose a multistep "roadmap" that provides an integrated strategy for molecular target discovery for repair of the injured spinal cord., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The regenerative capacity of injured neurons in the central nervous system is limited due to the absence of a robust neuron-intrinsic injury-induced gene response that supports axon regeneration. In peripheral neurons axotomy induces a large cohort of regeneration-associated genes (RAGs). The forced expression of some of these RAGs in injured neurons has some beneficial effect on axon regeneration, but the reported effects are rather small. Transcription factors (TFs) provide a promising class of RAGs. TFs are hubs in the regeneration-associated gene network, and potentially control the coordinate expression of many RAGs simultaneously. Here we discuss the use of combined experimental and computational methods to identify novel regeneration-associated TFs with a key role in initiating and maintaining the RAG-response in injured neurons. We propose that a relatively small number of hub TFs with multiple functional connections in the RAG network might provide attractive new targets for gene-based and/or pharmacological approaches to promote axon regeneration in the central nervous system.

Peripheral nerve injury in humans often leads to incomplete functional recovery. In this review we discuss the potential for gene therapy to be used as a strategy alongside surgical repair techniques for the study of peripheral nerve regeneration in rodent models and with a view to its eventual use for the promotion of successful regeneration in the clinic. Gene therapy vectors based on herpes simplex virus, adenovirus, lentivirus and adeno-associated virus have been developed to deliver genes to the neurons of the peripheral nervous system, i.e. primary sensory neurons in the dorsal root ganglia and primary motor neurons. Adenoviral and lentiviral vectors have also been used to transduce Schwann cells and fibroblasts in the injured nerve. We present an overview of these vectors, their application so far in the peripheral nervous system, their potential as vectors for enhancing peripheral nerve repair, and the successful interventions that have been demonstrated in animal models. We also discuss some of the limitations of current vectors and how they may be overcome. While the technology for gene delivery is approaching a state of readiness for clinical translation, the current range of therapeutic genes for the repair of the traumatically injured peripheral nerve is mostly limited to neurotrophic factors delivered to neurons, Schwann cells or possibly the target organs. Finally, therefore, we consider what type of therapeutic transgene may be desirable to enhance nerve regeneration in the future.

For many experiments in the study of the peripheral nervous system, it would be useful to genetically manipulate primary sensory neurons. We have compared vectors based on adeno-associated virus (AAV) serotypes 1, 2, 3, 4, 5, 6, and 8, and lentivirus (LV), all expressing green fluorescent protein (GFP), for efficiency of transduction of sensory neurons, expression level, cellular tropism, and persistence of transgene expression following direct injection into the dorsal root ganglia (DRG), using histological quantification and qPCR. Two weeks after injection, AAV1, AAV5, and AAV6 had transduced the most neurons. The time course of GFP expression from these three vectors was studied from 1 to 12 weeks after injection. AAV5 was the most effective serotype overall, followed by AAV1. Both these serotypes showed increasing neuronal transduction rates at later time points, with some injections of AAV5 yielding over 90% of DRG neurons GFP(+) at 12 weeks. AAV6 performed well initially, but transduction rates declined dramatically between 4 and 12 weeks. AAV1 and AAV5 both transduced large-diameter neurons, IB4(+) neurons, and CGRP(+) neurons. In conclusion, AAV5 is a highly effective gene therapy vector for primary sensory neurons following direct injection into the DRG.

Purpose: The primary motor pathway, the corticospinal tract, is a major target for spinal cord regeneration studies. One way of improving the regeneration of corticospinal axons is to introduce regeneration-associated genes into cortical motor neurons using viral vector delivery., Methods: We used an engineered Herpes Simplex virus (HSV1) with the EF1alpha promoter encoding either LacZ or GFP to transduce cortical neurons through retrograde transport following the injection of vector into adult rat striatum or spinal cord. After three-days to one-month post-injection, sections of brain and spinal cord were viewed with fluorescence microscopy or processed for LacZ histochemistry., Results: Many layer V motor cortical neurons were transduced following striatal injections. These were not corticospinal neurons as they were not fluorogold-labelled following tracer injection into spinal cord. Corticospinal neurons in both hemispheres were, however, transduced following direct vector injections into the dorsal column of spinal cord, yielding 250-400 transduced corticospinal neurons per animal. No non-pyramidal neurons or thalamic neurons were transduced by spinal injections., Conclusions: Therefore, this HSV1.EF1alpha vector is highly effective for the transduction of corticospinal neurons without direct injection into the brain and could be used to introduce regeneration-relevant genes into these neurons with the aim of regenerating the corticospinal tract.

Neuroma formation after peripheral nerve injury is detrimental to functional recovery and is therefore a significant clinical problem. The molecular basis for this phenomenon is not fully understood. Here, we show that the expression of the chemorepulsive protein semaphorin 3A (sema3A), but not semaphorin 3F, is increased in human neuroma tissue that has formed in severe obstetric brachial plexus lesions. Sema3A is produced by fibroblasts in the epineurial space and appears to be secreted into the extracellular matrix. It surrounds fascicles, minifascicles, or single axons, suggesting a role in fasciculation and inhibition of neurite outgrowth. Lentiviral vector-mediated knock-down of Neuropilin 1, the receptor for sema3A, leads to increased neurite outgrowth of F11 cells cultured on neuroma tissue, but not of F11 cells cultured on normal nerve tissue. These findings demonstrate the putative inhibitory role of sema3A in human neuroma tissue. Our observations are the first demonstration of the expression of sema3A in human neural scar tissue and support a role for this protein in the inhibition of axonal regeneration in injured human peripheral nerves. These findings contribute to the understanding of the outgrowth inhibitory properties of neuroma tissue.

Background: Inflammation around cell bodies of primary sensory neurons and retinal ganglion cells enhances expression of neuronal growth-associated genes and stimulates axonal regeneration. We have asked if inflammation would have similar effects on corticospinal neurons, which normally show little response to spinal cord injury. Lipopolysaccharide (LPS) was applied onto the pial surface of the motor cortex of adult rats with or without concomitant injury of the corticospinal tract at C4. Inflammation around corticospinal tract cell bodies in the motor cortex was assessed by immunohistochemistry for OX42 (a microglia and macrophage marker). Expression of growth-associated genes c-jun, ATF3, SCG10 and GAP-43 was investigated by immunohistochemistry or in situ hybridisation., Results: Application of LPS induced a gradient of inflammation through the full depth of the motor cortex and promoted c-Jun and SCG10 expression for up to 2 weeks, and GAP-43 upregulation for 3 days by many corticospinal neurons, but had very limited effects on neuronal ATF3 expression. However, many glial cells in the subcortical white matter upregulated ATF3. LPS did not promote sprouting of anterogradely labelled corticospinal axons, which did not grow into or beyond a cervical lesion site., Conclusion: Inflammation produced by topical application of LPS promoted increased expression of some growth-associated genes in the cell bodies of corticospinal neurons, but was insufficient to promote regeneration of the corticospinal tract.

Objective: To develop a technique that would permit the identification of dendritic cells (DC) in small volumes of preterm neonatal cord blood in order to investigate neonatal immune response in relation to infection and preterm labor., Methods: We used three-color flow cytometry and a fixed quantity of fluorospheres to determine absolute cell numbers. Four red cell lysis techniques, sample dilution, time delay experiments, and a comparison with traditional Ficoll cell separation techniques were performed. Absolute numbers of DC recovered using each technique were calculated and compared., Results: With increasing time delay, there was a statistically significant reduction in the numbers of leukocytes in adult blood. In contrast, there was a significant increase in leukocytes in umbilical cord blood. Sample dilution did not significantly affect the total number of leukocytes or DC. The use of the reagent Optilyse B (Immunotech, Oxford, UK) combined with an additional washing step produced the best discrimination of all populations based on light scatter properties. For the same blood sample, antibody labeling of whole blood resulted in a greater recovery of DC when compared to prior cell purification using a Ficoll density gradient., Conclusion: Using traditional Ficoll cell separation, cell manipulation requires large volumes of blood and leads to cell loss and alteration in phenotype. We have validated a novel method using small volumes of whole blood, diluted if necessary, and using red cell lysis to enable analysis of small volumes of preterm neonatal cord blood. This may permit further analysis of the contribution of the fetal immune response in the development of spontaneous preterm labor and preterm birth due to infection.

Room-temperature reaction of carbon monoxide with tri-tert-butylaluminum at atmospheric pressure yields the dimeric tert-butylacyl complex [tBu2AlC(O)tBu]2 (1). This unprecedented CO insertion into an aluminum-carbon bond is apparently made possible by the three-coordinate aluminum center in the tri-tert-butylaluminum starting material.

Background: Many changes in gene expression occur in distal stumps of injured nerves but the transcriptional control of these events is poorly understood. We have examined the expression of the transcription factors ATF3 and c-Jun by non-neuronal cells during Wallerian degeneration following injury to sciatic nerves, dorsal roots and optic nerves of rats and mice, using immunohistochemistry and in situ hybridization., Results: Following sciatic nerve injury--transection or transection and reanastomosis--ATF3 was strongly upregulated by endoneurial, but not perineurial cells, of the distal stumps of the nerves by 1 day post operation (dpo) and remained strongly expressed in the endoneurium at 30 dpo when axonal regeneration was prevented. Most ATF3+ cells were immunoreactive for the Schwann cell marker, S100. When the nerve was transected and reanastomosed, allowing regeneration of axons, most ATF3 expression had been downregulated by 30 dpo. ATF3 expression was weaker in the proximal stumps of the injured nerves than in the distal stumps and present in fewer cells at all times after injury. ATF3 was upregulated by endoneurial cells in the distal stumps of injured neonatal rat sciatic nerves, but more weakly than in adult animals. ATF3 expression in transected sciatic nerves of mice was similar to that in rats. Following dorsal root injury in adult rats, ATF3 was upregulated in the part of the root between the lesion and the spinal cord (containing Schwann cells), beginning at 1 dpo, but not in the dorsal root entry zone or in the degenerating dorsal column of the spinal cord. Following optic nerve crush in adult rats, ATF3 was found in some cells at the injury site and small numbers of cells within the optic nerve displayed weak immunoreactivity. The pattern of expression of c-Jun in all types of nerve injury was similar to that of ATF3., Conclusion: These findings raise the possibility that ATF3/c-Jun heterodimers may play a role in regulating changes in gene expression necessary for preparing the distal segments of injured peripheral nerves for axonal regeneration. The absence of the ATF3 and c-Jun from CNS glia during Wallerian degeneration may limit their ability to support regeneration.

The hydroformylation of alkenes is a major commercial process used for the production of oxygenated organic compounds. When the hydroformylation reaction is performed using a homogeneous catalyst, an organic or aqueous solvent is employed, and a significant effort must be expended to recover the catalyst so it can be recycled. Development of a selective heterogeneous catalyst would allow simplification of the process design in an integrated system that minimizes waste generation. Recent studies have shown that supercritical carbon dioxide (scCO2) as a reaction solvent offers optimal environmental performance and presents advantages for ease of product separation. In particular, we have considered the conversion of 1-hexene to heptanal using rhodium- and platinum-phosphine catalysts tethered to supports insoluble in scCO2 to demonstrate the advantages and to understand the limitations of a solid-catalyzed process. One of the historical limitations of supported catalysts is the inability to control product regioselectivity. To address this concern, we have developed tethered catalysts with phosphinated silica and controlled pore size MCM-41 and MCM-20 supports that provide improved regioselectivity and conversion relative to their nonporous equivalents. Platinum catalysts supported on MCM-type supports were the most regioselective whereas the analogous rhodium catalysts were the most active for hydroformylation of 1-hexene in scCO2.

2,2'-Di(3-methylindolyl)methanes (L(2)H(2)) are introduced as dianionic, bidentate ligands of reduced pi-donating ability. Four complexes of the type L(2)Ti(NEt(2))(2) and L(2)Zr(NEt(2))(2)(THF) have been synthesized and characterized by elemental analysis, NMR ((1)H, (13)C) spectroscopy, and X-ray crystallography. Structural data confirm the reduced pi-donating ability of the eta(1)-indolyl moiety compared to that of diethylamido. Preliminary catalytic activities of these group 4 complexes for the polymerization of ethylene are reported.

The failure of some CNS neurons to up-regulate growth-associated genes following axotomy may contribute to their failure to regenerate axons. We have studied gene expression in rat corticospinal neurons following either proximal (intracortical) or distal (spinal) axotomy. Corticospinal neurons were retrogradely labelled with cholera toxin subunit B prior to intracortical lesions or concomitantly with spinal lesions. Alternate sections of forebrain were immunoreacted for cholera toxin subunit B or processed for mRNA in situ hybridization for ATF3, c-jun, GAP-43, CAP-23, SCG10, L1, CHL1 or krox-24, each of which has been associated with axotomy or axon regeneration in other neurons. Seven days after intracortical axotomy, ATF3, c-jun, GAP-43, SCG10, L1 and CHL1, but not CAP-23 or krox-24, were up-regulated by layer V pyramidal neurons, including identified corticospinal neurons. The maximum distance between the lesion and the neuronal cell bodies that up-regulated genes varied between 300 and 500 microm. However, distal axotomy failed to elicit changes in gene expression in corticospinal neurons. No change in expression of any molecule was seen in the neocortex 1 or 7 days after corticospinal axotomy in the cervical spinal cord. The expression of GAP-43, CAP-23, L1, CHL1 and SCG10 was confirmed to be unaltered after this type of injury in identified retrogradely labelled corticospinal neurons. Thus, while corticospinal neuronal cell bodies fail to respond to spinal axotomy, these cells behave like regeneration-competent neurons, up-regulating a wide range of growth-associated molecules if axotomized within the cerebral cortex.

We have examined the expression of the immunophilin FKBP12 in adult rat intrinsic CNS neurons stimulated to regenerate axons by the implantation of segments of autologous tibial nerve into the thalamus or cerebellum. After survival times of 3 days to 6 weeks, the brains were fresh-frozen. In some animals the regenerating neurons were retrogradely labelled with cholera toxin subunit B 1 day before they were killed. Sections through the thalamus or cerebellum were used for in situ hybridization with digoxygenin-labelled riboprobes for FKBP12 or immunohistochemistry to detect cholera toxin subunit B-labelled neurons. FKBP12 was constitutively expressed by many neurons, and was very strongly expressed in the hippocampus and by Purkinje cells. Regenerating neurons were found in the thalamic reticular nucleus and deep cerebellar nuclei of animals that received living grafts. Neurons in these nuclei upregulated FKBP12 mRNA; such neurons were most numerous at 3 days post grafting but were most strongly labelled at 2 weeks post grafting. Regenerating neurons identified by retrograde labelling were found to have upregulated FKBP12 mRNA. No upregulation was seen in neurons in animals that received freeze-killed grafts, which do not support axonal regeneration. We conclude that FKBP12 is a regeneration-associated gene in intrinsic CNS neurons.

We have compared SCG10 and CAP-23 expression with that of GAP-43 during axonal regeneration in the peripheral and central nervous systems (PNS, CNS) of adult rats. SCG10, CAP-23, and GAP-43 mRNAs were strongly upregulated by motor and dorsal root ganglion (DRG) neurons following sciatic nerve crush, but not after dorsal rhizotomy. When the sciatic nerve was cut and ligated to prevent reinnervation of targets, expression of all three mRNAs was prolonged. Neurons in the thalamic reticular nucleus and deep cerebellar nuclei transiently upregulated these mRNAs after axotomy, and showed prolonged upregulation of all three molecules when regenerating axons into peripheral nerve grafts inserted into the thalamus of cerebellum. Neurons in the dorsal thalamus and cerebellar cortex showed poor regenerative capacity and most did not upregulate any of these mRNAs. Thus, in both PNS and CNS neurons, the transcription of SCG10, CAP-23, and GAP-43 mRNAs is coregulated following axotomy and during regeneration. Signals from living peripheral nerve appear to maintain expression of all three mRNAs in regenerating neurons, and in PNS neurons downregulation correlates with target reinnervation. Thus, SCG10 and CAP-23, as well as GAP-43, are likely to be important neuronal determinants of regenerative ability.

The expression of mRNA for Nogo-66 receptor (NgR) in unoperated adult rats and mice, and rats with nerve grafts placed in the thalamus and cerebellum to stimulate axonal regeneration, was investigated by in situ hybridization. NgR was strongly expressed in neurons of the neocortex, hippocampal formation, and amygdaloid nuclei and dorsal thalamus and moderately expressed in the red nucleus and vestibular nuclei. NgR mRNA was expressed in cerebellar deep nuclei and more strongly by granule cells than by Purkinje cells. Large regions of the forebrain, including the striatum, thalamic reticular nucleus, hypothalamus, and basal forebrain showed little or no NgR expression. NgR was weakly expressed in spinal neurons and some primary sensory neurons. Nerve implantation into the brain did not affect NgR expression. Some regeneration-competent neurons expressed NgR but others did not. Thus NgR expression was not correlated with the ability of neurons to regenerate axons into nerve grafts although Nogo-66 was strongly upregulated by some cells in the distal stumps of injured sciatic nerves. Nogo-66 transcripts were strongly expressed by many classes of CNS neurons and less strongly in white matter.

Variable-temperature (13)C NMR spectra for a series of Fe(CO)(4)(PR(3)) complexes ligated by phosphatri(3-methylindolyl)methane (1), phosphatri(pyrrolyl)methane (2), P(N-3-methylindolyl)(3) (3), and P(N-pyrrolyl)(3) (4) are reported. Ligand 2 was prepared by reaction of tri(pyrrolyl)methane with PCl(3) in THF and Et(3)N. Compound 2 is stable to methanolysis, hydrolysis, and aerial oxidation at room temperature. Reactions of 2 with selenium powder and Rh(acac)(CO)(2) yield phosphatri(pyrrolyl)methane selenide (5) and Rh(acac)(CO)(2) (6), respectively. The carbonyl stretching frequency in the IR spectrum of 6 and the magnitude of (1)J(Se)(-)(P) in the (31)P NMR spectrum of 5 indicate that 2 is a strong pi-acid and a weak sigma-base, commensurate with its lack of reactivity with CH(3)I. The trend in the decreasing basicity of 2 and related phosphines and phosphites was determined to be P(NMe(2))(3) > 3 > 4 > 1 > P(OPh)(3) > 2. IR data for a series of Rh(acac)(CO)(PR(3)) complexes indicate the trend in decreasing pi-acceptor ability to be 2 approximately 1 > 4 > P(OPh)(3) > 3 > PPh(3). Phosphines 1-4 were reacted with Fe(2)(CO)(9) to yield Fe(CO)(4)(1) (7), Fe(CO)(4)(2) (8), Fe(CO)(4)(3) (9), and Fe(CO)(4)(4) (10), respectively. IR data for 7-10 support the trend in pi-acidity listed above. Variable-temperature (13)C NMR spectra for compounds 8-10 show a single doublet resonance for the carbonyls in the temperature range from -80 to 20 degrees C indicative of rapid intramolecular rearrangement of carbonyls between axial and equatorial sites. However, the (13)C NMR spectrum for 7 shows slowed axial-equatorial carbonyl exchange at 20 degrees C. The limiting slow-exchange spectrum is observed at -20 degrees C. Hindered carbonyl exchange in 7 is attributed to the rigid 3-fold symmetry and steric bulk of 1. In addition to characterization of the new compounds by NMR ((1)H, (13)C, and (31)P) spectroscopy, IR spectroscopy, mass spectrometry, and elemental analysis, compounds 2, 7, 9, and 10 were further characterized by X-ray crystallography.

It is well established that some populations of neurons of the adult rat central nervous system (CNS) will regenerate axons into a peripheral nerve implant, but others, including most thalamocortical projection neurons, will not. The ability to regenerate axons may depend on whether neurons can express growth-related genes such as GAP-43, whose expression correlates with axon growth during development and with competence to regenerate. Thalamic projection neurons which fail to regenerate into a graft also fail to upregulate GAP-43. We have tested the hypothesis that the absence of strong GAP-43 expression by the thalamic projection neurons prevents them from regenerating their axons, using transgenic mice which overexpress GAP-43. Transgene expression was mapped by in situ hybridization with a digoxigenin-labeled RNA probe and by immunohistochemistry with a monoclonal antibody against the GAP-43 protein produced by the transgene. Many CNS neurons were found to express the mRNA and protein, including neurons of the mediodorsal and ventromedial thalamic nuclei, which rarely regenerate axons into peripheral nerve grafts. Grafts were implanted into the region of these nuclei in the brains of transgenic animals. Although these neurons strongly expressed the transgene mRNA and protein and transported the protein to their axon terminals, they did not regenerate axons into the graft, suggesting that lack of GAP-43 expression is not the only factor preventing thalamocortical neurons regenerating their axons., (Copyright 2000 Academic Press.)