Developing a rapid and highly efficient cowpea regeneration, transformation and genome editing system using embryonic axis explants.

Cowpea (Vigna unguiculata (L.) Walp.) is one of the most important legume crops planted worldwide, but despite decades of effort, cowpea transformation is still challenging due to inefficient Agrobacterium-mediated transfer DNA delivery, transgenic selection and in vitro shoot regeneration. Here, we report a highly efficient transformation system using embryonic axis explants isolated from imbibed mature seeds. We found that removal of the shoot apical meristem from the explants stimulated direct multiple shoot organogenesis from the cotyledonary node tissue. The application of a previously reported ternary transformation vector system provided efficient Agrobacterium-mediated gene delivery, while the utilization of spcN as selectable marker enabled more robust transgenic selection, plant recovery and transgenic plant generation without escapes and chimera formation. Transgenic cowpea plantlets developed exclusively from the cotyledonary nodes at frequencies of 4% to 37% across a wide range of cowpea genotypes. CRISPR/Cas-mediated gene editing was successfully demonstrated. The transformation principles established here could also be applied to other legumes to increase transformation efficiencies.

Ectopic expression of ARGOS8 reveals a role for ethylene in root-lodging resistance in maize.

Ethylene plays a critical role in many diverse processes in plant development. Recent studies have demonstrated that overexpression of the maize ARGOS8 gene reduces the plant's response to ethylene by decreasing ethylene signaling and enhances grain yield in transgenic maize plants. The objective of this study was to determine the effects of ethylene on the development of nodal roots, which are primarily responsible for root-lodging resistance in maize. Exogenous application of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) was found to promote the emergence of nodal roots. Transcriptome analysis of nodal tissues revealed that the expression of genes involved in metabolic processes and cell wall biogenesis was upregulated in response to ACC treatment, supporting the notion that ethylene is a positive regulator for the outgrowth of young root primordia. In BSV::ARGOS8 transgenic plants with reduced ethylene sensitivity due to constitutive overexpression of ARGOS8, nodal root emergence was delayed and the promotional effect of ACC on nodal root emergence decreased. Field tests showed that the BSV::ARGOS8 plants had higher root lodging relative to non-transgenic controls. When ARGOS8 expression was controlled by the developmentally regulated promoter FTM1, which conferred ARGOS8 overexpression in adult plants but not in the nodal roots and nodes in juvenile plants, the FTM1::ARGOS8 plants had no significant difference in root lodging compared with the wild type but produced a higher grain yield. These results suggest that ethylene has a role in promoting nodal root emergence and that a delay in nodal root development has a negative effect on root-lodging resistance in maize.

US Food and Drug Administration Approval of Whole Slide Imaging for Primary Diagnosis: A Key Milestone Is Reached and New Questions Are Raised.

April 12, 2017 marked a significant day in the evolution of digital pathology in the United States, when the US Food and Drug Administration announced its approval of the Philips IntelliSite Pathology Solution for primary diagnosis in surgical pathology. Although this event is expected to facilitate more widespread adoption of whole slide imaging for clinical applications in the United States, it also raises a number of questions as to the means by which pathologists might choose to incorporate this technology into their clinical practice. This article from the College of American Pathologists Digital Pathology Committee reviews frequently asked questions on this topic and provides answers based on currently available information.

Effectiveness of an HIV prevention intervention in prison among African Americans, Hispanics, and Caucasians.

Prisons and prison inmates present important targets for HIV/AIDS prevention interventions. Inmates often have histories of high-risk behavior that place them in danger of contracting HIV/AIDS, and rates of HIV/AIDS tend to be much higher in this population. The goal of this study was to assess the effectiveness of a prison-based HIV/AIDS intervention to change attitudes toward HIV prevention, norms supporting HIV prevention, perceived behavioral control (i.e., self-efficacy) for HIV prevention behaviors, and intentions to engage in HIV prevention behaviors postrelease. The intervention also had the goal of encouraging inmates to become HIV/AIDS peer educators. The intervention appeared most successful at influencing beliefs and behaviors related to peer education and somewhat successful at influencing beliefs and intentions related to condom use. Analyses also showed some significant differences in effectiveness by race/ethnicity. Results are discussed from the perspectives of both research and practice with regard to prison-based HIV prevention efforts.

A placebo-controlled trial of a proprietary extract of North American ginseng (CVT-E002) to prevent acute respiratory illness in institutionalized older adults.

OBJECTIVES: To compare a proprietary extract of American ginseng, CVT-E002, with placebo in preventing acute respiratory illness (ARI) in an institutional setting during the influenza season. DESIGN: Two randomized, double-blind, placebo-controlled trials conducted late in the 2000 (8 week) and 2000-2001 (12 week) influenza seasons. SETTING: Long-term care setting that included nursing home and assisted living at three sites. PARTICIPANTS: Eighty-nine (2000) and 109 (2000-2001) enrolled subjects, average age 81 and 83.5, respectively; 74% women. Approximately 90% had received influenza vaccine in each of the 2 years. INTERVENTION: Oral twice-daily administration of a proprietary ginseng extract, CVT-E002, 200 mg or placebo. MEASUREMENTS: ARI was defined as two new respiratory symptoms or one with a constitutional symptom. Confirmation of viral ARI was by culture (influenza or respiratory syncytial virus (RSV)) or serology for influenza. Laboratory safety monitoring was done at 0, 4, and 8 or 12 weeks. RESULTS: An intent-to-treat analysis of pooled data corrected for drug exposure time showed that the incidence of laboratory-confirmed influenza illness (LCII) was greater in placebo- (7 cases/101 subjects) than CVT-E002-treated (1/97) groups (odds ratio (OR)=7.73, P=.033). Combined data for LCII and RSV illness were also greater in placebo- (9/101) than CVT-E002-treated (1/97) groups (OR=10.50, P=.009), for an overall 89% relative risk reduction of ARI in the CVT-E002 group. CONCLUSION: CVT-E002 was shown to be safe, well tolerated, and potentially effective for preventing ARI due to influenza and RSV.

Validation of a whole slide imaging system for primary diagnosis in surgical pathology: A community hospital experience.

Guidelines for validating whole slide imaging (WSI) for primary diagnosis in surgical pathology have been recommended by an expert panel commissioned by the College of American Pathologists. The implementation of such a system using these validation guidelines has not been reported from the community hospital setting. The objective was to implement a WSI system, validate each pathologist using the system and run the system in parallel with routine glass slide interpretation. Six pathologists re-reviewed approximately 300 previously diagnosed specimens each, divided equally between glass slides and digital images (scanned at ×20). Baseline intraobserver discordance rates (glass to glass) were calculated and compared to discordance rates between the original glass slide interpretation and the reviewed digital slide interpretation. A minimum of 3 months was used as the washout period. After validation, a subset of daily cases was diagnosed in parallel using traditional microscopy (TM) and WSI over an 8-month period. The TM and WSI discordance rates ranged from 3.3% to 13.3% and 2.1% to 10.1%, respectively. There was no statistically significant difference among the pathologists. The parallel study yielded similar rates of discordances. In our laboratory, after appropriate implementation and training, there was no difference between the WSI and TM methods.

Arabidopsis E2Fa plays a bimodal role in regulating cell division and cell growth.

The onset of cell cycle in mammalian systems is primarily controlled by E2F-like transcription factors. Recent evidence shows that plant E2F homologs and their associated proteins likely play similar roles in higher plant development. We studied the function of plant E2F in gene regulation and morphogenesis using transgenic Arabidopsis plants over-expressing AtE2Fa. Examination of rosettes showed that AtE2Fa over-expression resulted in increased expression of both cell cycle promoters and cell cycle inhibitors. The positive factors up-regulated by AtE2Fa emcompassed genes for G1/S transition, DNA synthesis and mitosis, and the negative factors up-regulated by AtE2Fa included RB1 , encoding the E2F binding protein, as well as KRP3 and KRP5 , encoding the plant CDK inhibitors. Moreover, AtE2Fa over-expression in rosettes led to elevated expression of ATPK19 , the homolog of the highly conserved S6 kinase that is known to enhance cell growth. The transgenic plants exhibited narrower rosette leaves when compared to wild-type control. Consistent with elevated expression of cell cycle inhibitors and ATPK19 , the mature rosette leaves displayed reduced cell number but increased cell size. These results demonstrate that AtE2Fa controls cell division and plant development by assuming a bimodal function in balancing the expression of both positive and negative regulators involved in cell division and growth.

Method detection limit determination and application of a convenient headspace analysis method for methyl tert-butyl ether in water.

Methyl tert-butyl ether (MTBE) is a common groundwater contaminant, introduced to the environment by leaking petroleum storage tanks, urban runoff, and motorized watercraft. In this study. a simplified (static) headspace analysis method was adapted for determination of MTBE in water samples and soil water extracts. The MDL of the headspace method was calculated to be 2.0 microg L(-1) by the EPA single-concentration design method(1) and 1.2 microg L(-1) by a calibration method developed by Hubaux and Vos (Hubaux, A.; Vos, G. Anal. Chem. 1970,42, 849-855). The MDL calculated with the Hubaux and Vos method was favored because it considers both a true positive and a false positive. The static headspace method was applied to analysis of a tap water sample and a monitoring well sample from a gasoline service station, a river sample, and aqueous extracts from soil excavated during removal of a leaking underground storage tank (LUST). The water samples examined in this study had MTTBE concentrations ranging from 6 to 19 microg L(-1). Aqueous extracts of a soil sample taken from the LUST site had 8 microg L(-1) MTBE.