Genomics of Aminoglycoside Resistance in Pseudomonas aeruginosa Bloodstream Infections at a United States Academic Hospital

Pseudomonas aeruginosa frequently becomes resistant to aminoglycosides by the acquisition of aminoglycoside modifying enzyme (AME) genes and the occurrence of mutations in the mexZ, fusA1, parRS, and armZ genes. We examined resistance to aminoglycosides in a collection of 227 P. aeruginosa bloodstream isolates collected over 2 decades from a single United States academic medical institution. Resistance rates of tobramycin and amikacin were relatively stable over this time, while the resistance rates of gentamicin were somewhat more variable. For comparison, we examined resistance rates to piperacillin-tazobactam, cefepime, meropenem, ciprofloxacin, and colistin. Resistance rates to the first four antibiotics were also stable, although uniformly higher for ciprofloxacin. Colistin resistance rates were initially quite low, rose substantially, and then began to decrease at the end of the study. Clinically relevant AME genes were identified in 14% of isolates, and mutations predicted to cause resistance were relatively common in the mexZ and armZ genes. In a regression analysis, resistance to gentamicin was associated with the presence of at least one gentamicin-active AME gene and significant mutations in mexZ, parS, and fusA1. Resistance to tobramycin was associated with the presence of at least one tobramycin-active AME gene. An extensively drug-resistant strain, PS1871, was examined further and found to contain five AME genes, most of which were within clusters of antibiotic resistance genes embedded in transposable elements. These findings demonstrate the relative contributions of aminoglycoside resistance determinants to P. aeruginosa susceptibilities at a United States medical center. IMPORTANCE Pseudomonas aeruginosa is frequently resistant to multiple antibiotics, including aminoglycosides. The rates of resistance to aminoglycosides in bloodstream isolates collected over 2 decades at a United States hospital remained constant, suggesting that antibiotic stewardship programs may be effective in countering an increase in resistance. Mutations in the mexZ, fusA1, parR, pasS, and armZ genes were more common than acquisition of genes encoding aminoglycoside modifying enzymes. The whole-genome sequence of an extensively drug resistant isolate indicates that resistance mechanisms can accumulate in a single strain. Together, these results suggest that aminoglycoside resistance in P. aeruginosa remains problematic and confirm known resistance mechanisms that can be targeted for the development of novel therapeutics.

Skimming for barcodes: rapid production of mitochondrial genome and nuclear ribosomal repeat reference markers through shallow shotgun sequencing

DNA barcoding is critical to conservation and biodiversity research, yet public reference databases are incomplete. Existing barcode databases are biased toward cytochrome oxidase subunit I (COI) and frequently lack associated voucher specimens or geospatial metadata, which can hinder reliable species assignments. The emergence of metabarcoding approaches such as environmental DNA (eDNA) has necessitated multiple marker techniques combined with barcode reference databases backed by voucher specimens. Reference barcodes have traditionally been generated by Sanger sequencing, however sequencing multiple markers is costly for large numbers of specimens, requires multiple separate PCR reactions, and limits resulting sequences to targeted regions. High-throughput sequencing techniques such as genome skimming enable assembly of complete mitogenomes, which contain the most commonly used barcoding loci (e.g., COI, 12S, 16S), as well as nuclear ribosomal repeat regions (e.g., ITS1&2, 18S). We evaluated the feasibility of genome skimming to generate barcode references databases for marine fishes by assembling complete mitogenomes and nuclear ribosomal repeats. We tested genome skimming across a taxonomically diverse selection of 12 marine fish species from the collections of the National Museum of Natural History, Smithsonian Institution. We generated two sequencing libraries per species to test the impact of shearing method (enzymatic or mechanical), extraction method (kit-based or automated), and input DNA concentration. We produced complete mitogenomes for all non-chondrichthyans (11/12 species) and assembled nuclear ribosomal repeats (18S-ITS1-5.8S-ITS2-28S) for all taxa. The quality and completeness of mitogenome assemblies was not impacted by shearing method, extraction method or input DNA concentration. Our results reaffirm that genome skimming is an efficient and (at scale) cost-effective method to generate all mitochondrial and common nuclear DNA barcoding loci for multiple species simultaneously, which has great potential to scale for future projects and facilitate completing barcode reference databases for marine fishes.

Environmental DNA from Marine Waters and Substrates: Protocols for Sampling and eDNA Extraction

Environmental DNA (eDNA) analysis has emerged in recent years as a powerful tool for the detection, monitoring, and characterization of aquatic metazoan communities, including vulnerable species. The rapid rate of adopting the eDNA approach across diverse habitats and taxonomic groups attests to its value for a wide array of investigative goals, from understanding natural or changing biodiversity to informing on conservation efforts at local and global scales. Regardless of research objectives, eDNA workflows commonly include the following essential steps: environmental sample acquisition, processing and preservation of samples, and eDNA extraction, followed by eDNA sequencing library preparation, high-capacity sequencing and sequence data analysis, or other methods of genetic detection. In this chapter, we supply instructional details for the early steps in the workflow to facilitate researchers considering adopting eDNA analysis to address questions in marine environments. Specifically, we detail sampling, preservation, extraction, and quantification protocols for eDNA originating from marine water, shallow substrates, and deeper sediments. eDNA is prone to degradation and loss, and to contamination through improper handling; these factors crucially influence the outcome and validity of an eDNA study. Thus, we also provide guidance on avoiding these pitfalls. Following extraction, purified eDNA is often sequenced on massively parallel sequencing platforms for comprehensive faunal diversity assessment using a metabarcoding or metagenomic approach, or for the detection and quantification of specific taxa by qPCR methods. These components of the workflow are project-specific and thus not included in this chapter. Instead, we briefly touch on the preparation of eDNA libraries and discuss comparisons between sequencing approaches to aid considerations in project design.

The complete mitochondrial genome of Costapex baldwinae (Gastropoda: Neogastropoda: Turbinelloidea: Costellariidae) from the Caribbean Deep-Sea

We report the complete mitochondrial genome sequence of Costapex baldwinae, a Caribbean representative of a predominantly Indo-Pacific genus of gastropods that occurs on sunken wood at bathyal depths. The mitogenome is 15,321 bp in length and has a base composition of 29.2% A, 41.8% T, 12.0% C and 17.0% G. It contains 13 protein-coding, two ribosomal RNA, and 22 tRNA genes with the same gene order and strand orientation as other non-toxoglossan neogastropods. Phylogenetic analyses indicate that the superfamily Turbinelloidea, represented by this species, diverged early within the Neogastropod radiation, forming the sister group to a clade that includes five of the seven presently recognized superfamilies.

Comparison of genomic diversity and structure of sable antelope (Hippotragus niger) in zoos, conservation centers, and private ranches in North America

As we enter the sixth mass extinction, many species that are no longer self-sustaining in their natural habitat will require ex situ management. Zoos have finite resources for ex situ management, and there is a need for holistic conservation programs between the public and private sector. Ex situ populations of sable antelope, Hippotragus niger, have existed in zoos and privately owned ranches in North America since the 1910s. Unknown founder representation and relatedness has made the genetic management of this species challenging within zoos, while populations on privately owned ranches are managed independently and retain minimal-to-no pedigree history. Consequences of such challenges include an increased risk of inbreeding and a loss of genetic diversity. Here, we developed and applied a customized targeted sequence capture panel based on 5,000 genomewide single-nucleotide polymorphisms to investigate the genomic diversity present in these uniquely managed populations. We genotyped 111 sable antelope: 23 from zoos, 43 from a single conservation center, and 45 from ranches. We found significantly higher genetic diversity and significantly lower inbreeding in herds housed in zoos and conservation centers, when compared to those in privately owned ranches, likely due to genetic-based breeding recommendations implemented in the former populations. Genetic clustering was strong among all three populations, possibly as a result of genetic drift. We propose that the North American ex situ population of sable antelope would benefit from a metapopulation management system, to halt genetic drift, reduce the occurrence of inbreeding, and enable sustainable population sizes to be managed ex situ.

Characterization of the complete mitochondrial genome of Amblyomma ovale, comparative analyses and phylogenetic considerations

In this study, we sequenced two complete mitochondrial genomes of Amblyomma ovale, a tick of public health importance. Sequencing two distinct individuals, the resulting mitochondrial genomes were 14,756 and 14,760 bp in length and maintained the same gene order previously reported in Amblyomma. These were combined with RNA-seq derived mitochondrial sequences from three additional species, Amblyomma aureolatum, Amblyomma maculatum, and Amblyomma moreliae, to carry out mitogenome comparative and evolutionary analyses against all previously published tick mitochondrial genomes. We described a derivative genome rearrangement that isolates Ixodes from the remaining Ixodidae and consists of both a reverse translocation as well as an event of Tandem Duplication Random Loss. Genetic distance analyses indicated that cox2, nd1, nd5, and 16S are good candidates for future population studies in A. ovale. The phylogenetic analyses corroborated the utility of complete mitochondrial genomes as phylogenetic markers within the group. This study further supplements the genome information available for Amblyomma and facilitates future evolutionary and population genetic studies within the genus.

The complete mitochondrial genome of the critically endangered Atlantic humpback dolphin, Sousa teuszii (Kükenthal, 1892)

The Atlantic humpback dolphin remains an understudied, critically endangered cetacean species. Here, we describe the first complete mitogenome of Sousa teuszii, derived from an animal stranded on Île des Oiseaux, Sine Saloum, Senegal. The S. teuszii mitogenome is composed of 16,384 base pairs and is 98.1% identical to its closest relative with a mitogenome, Sousa chinensis. Phylogenetic analysis confirms its placement with S. chinensis, as well as the placement of the genus Sousa within subfamily Delphininae.

The genomic basis for colonizing the freezing Southern Ocean revealed by Antarctic toothfish and Patagonian robalo genomes

Background

The Southern Ocean is the coldest ocean on Earth but a hot spot of evolution. The bottom-dwelling Eocene ancestor of Antarctic notothenioid fishes survived polar marine glaciation and underwent adaptive radiation, forming >120 species that fill all water column niches today. Genome-wide changes enabling physiological adaptations and the rapid expansion of the Antarctic notothenioids remain poorly understood.

Results

We sequenced and compared 2 notothenioid genomes—the cold-adapted and neutrally buoyant Antarctic toothfish Dissostichus mawsoni and the basal Patagonian robalo Eleginops maclovinus, representing the temperate ancestor. We detected >200 protein gene families that had expanded and thousands of genes that had evolved faster in the toothfish, with diverse cold-relevant functions including stress response, lipid metabolism, protein homeostasis, and freeze resistance. Besides antifreeze glycoprotein, an eggshell protein had functionally diversified to aid in cellular freezing resistance. Genomic and transcriptomic comparisons revealed proliferation of selcys–transfer RNA genes and broad transcriptional upregulation across anti-oxidative selenoproteins, signifying their prominent role in mitigating oxidative stress in the oxygen-rich Southern Ocean. We found expansion of transposable elements, temporally correlated to Antarctic notothenioid diversification. Additionally, the toothfish exhibited remarkable shifts in genetic programs towards enhanced fat cell differentiation and lipid storage, and promotion of chondrogenesis while inhibiting osteogenesis in bone development, collectively contributing to the achievement of neutral buoyancy and pelagicism.

Conclusions

Our study revealed a comprehensive landscape of evolutionary changes essential for Antarctic notothenioid cold adaptation and ecological expansion. The 2 genomes are valuable resources for further exploration of mechanisms underlying the spectacular notothenioid radiation in the coldest marine environment.

A tale of two genes: divergent evolutionary fate of haptoglobin and hemopexin in hemoglobinless antarctic icefishes

Evolution of Antarctic notothenioid fishes in the isolated freezing Southern Ocean have led to remarkable trait gains and losses. One of the most extraordinary was the loss of the major oxygen carrier hemoglobin (Hb) in the icefishes (family Channichthyidae). While the mechanisms of this loss and the resulting compensatory changes have been well studied, the impact of Hb loss on the network of genes that once supported its recycling and disposal has remained unexplored. Here we report the functional fate and underlying molecular changes of two such key Hb-supporting proteins across the icefish family - haptoglobin (Hp) and hemopexin (Hx), crucial in removing cytotoxic free Hb and heme respectively. Hp plays a critical role in binding free Hb for intracellular recycling and absent its primary client, icefish Hp transcription is now vanishingly little and translation into a functional protein is nearly silenced. Hp genotype degeneration has manifested in separate lineages of the icefish phylogeny with three distinct nonsense mutations and a deletion-frameshift, as well as mutated polyadenylation signal sequences. Thus, Hb loss appears to have diminished selective constraint on Hp maintenance, resulting in its stochastic, co-evolutionary drift towards extinction. Hx binds free heme for iron recycling in hepatocytes. In contrast to Hp, Hx genotype integrity is preserved in the icefishes and transcription occurs at comparable levels to the red-blooded notothenioids. The persistence of Hx likely owes to continued selective pressure for its function from mitochondrial and non-Hb cellular hemoproteins.

A diagnosis of the plasma waves responsible for the explosive energy release of substorm onset

During geomagnetic substorms, stored magnetic and plasma thermal energies are explosively converted into plasma kinetic energy. This rapid reconfiguration of Earth's nightside magnetosphere is manifest in the ionosphere as an auroral display that fills the sky. Progress in understanding of how substorms are initiated is hindered by a lack of quantitative analysis of the single consistent feature of onset; the rapid brightening and structuring of the most equatorward arc in the ionosphere. Here, we exploit state-of-the-art auroral measurements to construct an observational dispersion relation of waves during substorm onset. Further, we use kinetic theory of high-beta plasma to demonstrate that the shear Alfven wave dispersion relation bears remarkable similarity to the auroral dispersion relation. In contrast to prevailing theories of substorm initiation, we demonstrate that auroral beads seen during the majority of substorm onsets are likely the signature of kinetic Alfven waves driven unstable in the high-beta magnetotail.

Photochemistry Illuminates Ubiquitous Organic Matter Fluorescence Spectra

Dissolved organic matter (DOM) in aquatic environments forms a vast reservoir of carbon present as a complex supermixture of compounds. An efficient approach to tracking the production and removal of specific DOM fractions is needed across disciplines, for purposes that range from improving global carbon budgets to optimizing water treatment in engineered systems. Although widely used to study DOM, fluorescence spectroscopy has yet to deliver specific fractions with known spectral properties and predictable distributions. Here, we mathematically isolate four visible-wavelength fluorescent fractions in samples from contrasting lake, river, and ocean environments. Using parallel factor analysis (PARAFAC), we show that most measured fluorescence in environmental samples can be explained by ubiquitous spectra with nearly stable optical properties and photodegradation behaviors over environmental pH gradients. Sample extraction changed bulk fluorescence spectra but not the number or shape of underlying PARAFAC components, while photobleaching preferentially removed the two longest-wavelength components. New approaches to analyzing fluorescence data sets incorporating these findings should improve the interpretation of DOM fluorescence and increase its utility for tracing organic matter biogeochemistry in aquatic systems.

Long-lasting poloidal ULF waves observed by multiple satellites and high-latitude SuperDARN radars

Poloidal ultra-low frequency (ULF) waves between 5-10 mHz were observed by multiple satellites and three high-latitude Super Dual Auroral Radar Network (SuperDARN) radars during the recovery phase of a moderate geomagnetic storm on Jan 24-27, 2016. The long-lasting ULF waves were observed in the magnetic field and energetic particle flux perturbations during three successive passes by two Geostationary Operational Environmental Satellites (GOES) through the dayside magnetosphere, during which plasmasphere expansion and refilling were observed by two Time History of Events and Macroscale Interactions during Substorms (THEMIS) probes. The radial magnetic field oscillation was in phase (~ 180° out of phase) with the northward (southward) moving proton flux oscillation at 95 keV, consistent with high-energy drift-bounce resonance signatures of protons with second harmonic poloidal standing Alfvén waves. The longitudinal extent of the waves approached 10 hours in local time on the dayside and gradually decreased with time. High-time resolution (~ 6 s) data from three high-latitude SuperDARN radars show that the wave intensification region was localized in latitude with a radial extent of ~ 135-225 km in the subauroral ionosphere. No signature of these waves were observed by ground-based magnetometers colocated with the GOES satellites suggesting that the poloidal waves were high-m mode and thus screened by the ionosphere. During this interval one of the THEMIS probes observed a bump-on-tail ion distribution at 1-3 keV which we suggest is the source of the long-lasting second harmonic poloidal ULF waves.

Environmental reservoirs for exoS+ and exoU+ strains of Pseudomonas aeruginosa

Pseudomonas aeruginosa uses its type III secretion system to inject the effector proteins ExoS and ExoU into eukaryotic cells, which subverts these cells to the bacterium's advantage and contributes to severe infections. We studied the environmental reservoirs of exoS+ and exoU+ strains of P. aeruginosa by collecting water, soil, moist substrates and plant samples from environments in the Chicago region and neighbouring states. Whole-genome sequencing was used to determine the phylogeny and type III secretion system genotypes of 120 environmental isolates. No correlation existed between geographic separation of isolates and their genetic relatedness, which confirmed previous findings of both high genetic diversity within a single site and the widespread distribution of P. aeruginosa clonal complexes. After excluding clonal isolates cultured from the same samples, 74 exoS+ isolates and 16 exoU+ isolates remained. Of the exoS+ isolates, 41 (55%) were from natural environmental sites and 33 (45%) were from man-made sites. Of the exoU+ isolates, only 3 (19%) were from natural environmental sites and 13 (81%) were from man-made sites (p < 0.05). These findings suggest that man-made water systems may be a reservoir from which patients acquire exoU+ P. aeruginosa strains.

Reconstruction of the repetitive antifreeze glycoprotein genomic loci in the cold-water gadids Boreogadus saida and Microgadus tomcod

Antifreeze glycoproteins (AFGPs) are a novel evolutionary innovation in members of the northern cod fish family (Gadidae), crucial in preventing death from inoculative freezing by environmental ice in their frigid Arctic and sub-Arctic habitats. However, the genomic origin and molecular mechanism of evolution of this novel life-saving adaptive genetic trait remained to be definitively determined. To this end, we constructed large insert genomic DNA BAC (bacterial artificial chromosome) libraries for two AFGP-bearing gadids, the high-Arctic polar cod Boreogadus saida and the cold-temperate Atlantic tomcod Microgadus tomcod, to isolate and sequence their AFGP genomic regions for fine resolution evolutionary analyses. The BAC library construction encountered poor cloning efficiency initially, which we resolved by pretreating the agarose-embedded erythrocyte DNA with a cationic detergent, a method that may be of general use to BAC cloning for teleost species and/or where erythrocytes are the source of input DNA. The polar cod BAC library encompassed 92,160 clones with an average insert size of 94.7 kbp, and the Atlantic tomcod library contained 73,728 clones with an average insert size of 89.6 kbp. The genome sizes of B. saida and M. tomcod were estimated by cell flow cytometry to be 836 Mbp and 645 Mbp respectively, thus their BAC libraries have approximately 10- and 9.7-fold genome coverage respectively. The inclusiveness and depth of coverage were empirically confirmed by screening the libraries with three housekeeping genes. The BAC clones that mapped to the AFGP genomic loci of the two gadids were then isolated by screening the BAC libraries with gadid AFGP gene probes. Eight minimal tiling path (MTP) clones were identified for B. saida, sequenced, and assembled. The B. saida AFGP locus reconstruction produced both haplotypes, and the locus comprises three distinct AFGP gene clusters, containing a total of 16 AFGP genes and spanning a combined distance of 512 kbp. The M. tomcod AFGP locus is much smaller at approximately 80 kbp, and contains only three AFGP genes. Fluorescent in situ hybridization with an AFGP gene probe showed the AFGP locus in both species occupies a single chromosomal location. The large AFGP locus with its high gene dosage in B. saida is consistent with its chronically freezing high Arctic habitats, while the small gene family in M. tomcod correlates with its milder habitats in lower latitudes. The results from this study provided the data for fine resolution sequence analyses that would yield insight into the molecular mechanisms and history of gadid AFGP gene evolution driven by northern hemisphere glaciation.

Fluorescence as a potential monitoring tool for recycled water systems: a review

A rapid, highly sensitive and selective detector is urgently required to detect contamination events in recycled water systems - for example, cross-connection events in dual reticulation pipes that recycle advanced treated sewage effluent - as existing technologies, including total organic carbon and conductivity monitoring, cannot always provide the sensitivity required. Fluorescence spectroscopy has been suggested as a potential monitoring tool given its high sensitivity and selectivity. A review of recent literature demonstrates that by monitoring the fluorescence of dissolved organic matter (DOM), the ratios of humic-like (Peak C) and protein-like (Peak T) fluorescence peaks can be used to identify trace sewage contamination in river waters and estuaries, a situation analogous to contamination detection in recycled water systems. Additionally, strong correlations have been shown between Peak T and biochemical oxygen demand (BOD) in rivers, which is indicative of water impacted by microbial activity and therefore of sewage impacted systems. Hence, this review concludes that the sensitive detection of contamination events in recycled water systems may be achieved by monitoring Peak T and/or Peak C fluorescence. However, in such systems, effluent is treated to a high standard resulting in much lower DOM concentrations and the impact of these advanced treatment processes on Peaks T and C fluorescence is largely unknown and requires investigation. This review has highlighted that further work is also required to determine (a) the stability and distinctiveness of recycled water fluorescence in relation to the treatment processes utilised, (b) the impact of matrix effects, particularly the impact of oxidation, (c) calibration issues for online monitoring, and (d) the advanced data analytical techniques required, if any, to improve detection of contamination events.

Time perception and reproduction in young adults with attention deficit hyperactivity disorder

Adults with attention deficit hyperactivity disorder (ADHD; n = 104) were compared with a control group (n = 64) on time estimation and reproduction tasks. Results were unaffected by ADHD subtype or gender. The ADHD group provided larger time estimations than the control group, particularly at long intervals. This became nonsignificant after controlling for IQ. The ADHD group made shorter reproductions than did the control group (15- and 60-s intervals) and greater reproduction errors (12-, 45-, 60-s durations). These differences remained after controlling for IQ and comorbid oppositional defiant disorder, depression, and anxiety. Only the level of anxiety contributed to errors (at 12-s duration) beyond the level of ADHD. Results extended findings on time perception in ADHD children to adults and ruled out comorbidity as the basis of the errors.

Time perception and reproduction in young adults with attention deficit hyperactivity disorder

Adults with attention deficit hyperactivity disorder (ADHD; n = 104) were compared with a control group (n = 64) on time estimation and reproduction tasks. Results were unaffected by ADHD subtype or gender. The ADHD group provided larger time estimations than the control group, particularly at long intervals. This became nonsignificant after controlling for IQ. The ADHD group made shorter reproductions than did the control group (15- and 60-s intervals) and greater reproduction errors (12-, 45-, 60-s durations). These differences remained after controlling for IQ and comorbid oppositional defiant disorder, depression, and anxiety. Only the level of anxiety contributed to errors (at 12-s duration) beyond the level of ADHD. Results extended findings on time perception in ADHD children to adults and ruled out comorbidity as the basis of the errors.

Executive functioning and olfactory identification in young adults with attention deficit-hyperactivity disorder

Young adults with attention deficit-hyperactivity disorder (ADHD; N = 105) were compared with a control group (N = 64) on 14 measures of executive function and olfactory identification using a 2 (group) X 2 (sex) design. The ADHD group performed significantly worse on 11 measures. No Group X Sex interaction was found on any measures. No differences were found in the ADHD group as a function of ADHD subtype or comorbid oppositional defiant disorder. Comorbid depression influenced the results of only 1 test (Digit Symbol). After IQ was controlled for, some group differences in verbal working memory, attention, and odor identification were no longer significant, whereas those in inhibition, interference control, nonverbal working memory, and other facets of attention remained so. Executive function deficits found in childhood ADHD exist in young adults with ADHD and are largely not influenced by comorbidity but may be partly a function of low intelligence.

The level of MHC class I expression on murine adenocarcinoma can change the antitumor effector mechanism of immunocytokine therapy

The huKS1/4-IL2 fusion protein, directed against the human epithelial cell adhesion molecule (huEpCAM) has been shown to induce a strong CD8+ T-cell-dependent, natural killer (NK) cell-independent, antitumor response in mice bearing the huEp-CAM-transfected CT26 colon cancer CT26-EpCAM. Here we investigate the effectiveness of huKS1/4-IL2 against CT26-Ep21.6, a subclone of CT26-EpCAM, expressing low levels of MHC class I. In vitro antibody-dependent cellular cytotoxicity (ADCC) assays in the presence of huKS1/4-IL2 demonstrate that murine NK cells from spleen and blood can kill CT26-Ep21.6 significantly better than they kill CT26-EpCAM. NK-mediated ADCC of CT26-EpCAM can be enhanced by blocking the murine NK cell-inhibitory receptor, Ly-49C. A potent in vivo antitumor effect was observed when BALB/c mice bearing experimental metastases of CT26-Ep21.6 were treated with huKS1/4-IL2. The depletion of NK cells during huKS1/4-IL2 treatment significantly reduced the antitumor effect against CT26-Ep21.6. Together our in vitro and in vivo data in the huEp-CAM-transfected CT26 models indicate that the amount of MHC class I expressed on the tumor target cell plays a critical role in the in vivo antitumor mechanism of huKS1/4-IL2 immunotherapy. A low MHC class I level favors NK cells as effectors, whereas a high level of MHC class I favors T cells as effectors. Given the heterogeneity of MHC class I expression seen in human tumors and the prevailing T-cell suppression in many cancer patients, the observation that huKS1/4-IL2 has the potential to effectively activate an NK cell-based antitumor response may be of potential clinical relevance.

Computer-based patient education

The computer can be a powerful ally in clinicians efforts to empower their patients to make the right individual decisions. The Internet, in particular, is an extremely valuable resource that enables patients to quickly obtain the latest information on support groups, therapeutic modalities, late-breaking research, and individual coping strategies. The technology is now mature enough that every provider should consider incorporating some type of computer-based patient education into his or her practice.

Performance evaluation in work settings

Recent research from 1993 on performance evaluations in work settings is reviewed and integrated with the prior reset and historical bases. Contemporary research reflects several themes: General models of job performance are being developed, the job performance domain is being expanded, research continues to explore the psychometric characteristics of performance ratings, research is developing on potential bias in ratings, rater training is examined, and research continues in terms of efforts to attach utility values to rated performance. We conclude that research is progressing in traditional content areas as well in the exploration of new ground. Researchers are recognizing that job performance is more than just the execution of specific tasks and that it involves a wider array of important organizational activities. There is also an increased optimism regarding the use of supervisory ratings and recognition that such "subjective" appraisal instruments do not automatically translate into rater error or bias.

Motor vehicle driving competencies and risks in teens and young adults with attention deficit hyperactivity disorder

PURPOSE

To evaluate the motor vehicle driving knowledge, skills, and negative driving outcomes of older teens and young adults with attention deficit hyperactivity disorder (ADHD).

LOCATION

A university medical center clinic for adult ADHD.

SUBJECTS

A total of 25 young adults with ADHD and 23 young adults without ADHD 17 to 30 years old drawn from the community and equated for age, gender, and educational level.

MEASURES

Structured interview, behavior ratings by self- and others, video test of driving knowledge, computer simulated driving test, and official motor vehicle records.

RESULTS

ADHD young adults were cited more often for speeding, were more likely to have had their licenses suspended, were involved in more crashes, were more likely to have had crashes causing bodily injury, and were rated by themselves and others as using poorer driving habits. Official driving records corroborated these negative outcomes. Although no group differences in driving knowledge were evident, young adults with ADHD had more crashes, scrapes, and erratic steering during the computer-stimulated driving test than did the control subjects.

CONCLUSIONS

Findings supported previous research suggesting that greater driving risks are associated with ADHD and suggested that ADHD does not interfere with driving knowledge so much as with actual performance (motor control) during vehicle operation.

Influence of job characteristics on the acceptability of employee drug testing

Measures of the acceptability of employee drug testing were obtained from a sample of college students (N = 371) and a second sample of nontraditional, older college students (N = 112) and were correlated with job-analysis data from the Position Analysis Questionnaire (PAQ) and Dictionary of Occupational Titles (DOT) databases, and with measures of perceived danger from impaired performance in each job. Both PAQ and DOT data accounted for variance in ratings of acceptability. Perceptions of danger were the best single predictor of acceptability and appeared to mediate the relationships between job characteristics and the acceptability of employee drug testing.

Refractory congestive heart failure after ribavirin in infants with heart disease and respiratory syncytial virus

Although treatment with ribavirin has been known to be associated with a decreased mortality in infants with congenital heart disease (CHD) who have respiratory syncytial virus (RSV), few data are available regarding morbidity. We reviewed records of 10 consecutively hospitalized infants with CHD during a recent RSV epidemic. Despite the presence of left-to-right shunt in each patient, symptoms of RSV were respiratory at presentation. After ribavirin, decreased respiratory symptoms were found in 8 infants but in 2 assisted ventilation were required 1 and 3 days after admission. Congestive heart failure worsened in 8 patients, 6 of whom had improved respiratory status after ribavirin. Of the 8 patients with worse CHF (pulmonary edema), 3 responded to medical management but 5 were refractory and 4 required surgical repair of CHD. One patient died of pulmonary hemorrhage. Medically refractory CHF may develop in infants with CHD who become infected with RSV and are treated with ribavirin. Further studies are needed to determine whether the pulmonary edema is caused by RSV, ribavirin, or combination of effects on pulmonary capillary function or some other unrecognized mechanism.

The requirement for polymorphonuclear leukocytes in the late asthmatic response and heightened airways reactivity in an animal model

The antigen-induced late asthmatic response (LAR) and subsequent heightened airways reactivity after this response have been associated with increased airways inflammation. Employing an animal model of the LAR in rabbits previously developed in our laboratory, 3 phases of experiments were performed to investigate the role of polymorphonuclear leukocytes (PML) in the LAR and heightened reactivity. In all 3 phases, airways reactivity to histamine and bronchoalveolar lavage analysis were performed 3 days before and 3 days after bronchial challenge with ragweed extract. In Phase 1, 2 groups of rabbits receiving nitrogen mustard were studied: an immune group received immune serum containing antiragweed IgE, and a control group received nonimmune serum. In Phase II, nitrogen mustard was administered to immune rabbits during aortic occlusion to allow the lungs to be exposed to nitrogen mustard while limiting exposure of the bone marrow to this drug, preventing depletion of PML. In Phase III, both an immune and a nonimmune group of rabbits received nitrogen mustard as in Phase I; however, prior to antigen challenge, they were repleted with a neutrophil-rich population of PML. In all experiments, no group of control (nonimmune) rabbits, whether depleted or repleted of PML, developed an immediate asthmatic response (IAR) or a LAR. In addition, no significant increases in lavage cells or airways reactivity occurred after ragweed challenge. In contrast, those animals receiving immune serum and nitrogen mustard developed an IAR; however, no LAR occurred, and no significant change in airways reactivity was observed. Rabbits receiving immune serum and nitrogen mustard with aortic occlusion developed an IAR and LAR, and airways reactivity increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Increases in airway reactivity to histamine and inflammatory cells in bronchoalveolar lavage after the late asthmatic response in an animal model

An increase in airway reactivity after the late asthmatic response (LAR) has been noted in humans. Although these alterations in reactivity have been proposed to be associated with inflammation, no clinical study of the LAR has shown both increased airway reactivity and evidence of pulmonary inflammation. Employing an animal model of the LAR in rabbits developed in our laboratory (Am Rev Respir Dis 1982; 126:493-498), we examined changes in airway reactivity and pulmonary inflammation in rabbits having a late asthmatic response. Two groups of rabbits were studied: a control group (n = 10) received nonimmune serum, and a sensitized group (n = 10) received serum containing homocytotropic antibody (IgE) to ragweed extract (RWE) from rabbits previously immunized from birth with ragweed. Airway reactivity to histamine and the evaluation of different cell types in bronchoalveolar lavage fluid were determined 3 days before and 3 days after bronchial challenge with RWE in all rabbits. No control rabbit developed a LAR, and no significant changes occurred in this group's airway reactivity or cells in lavage fluid after bronchial challenge with RWE. In contrast, all sensitized rabbits developed a LAR, and airway reactivity for this group was markedly increased 3 days later. In addition, the total number of cells including both polymorphonuclear and mononuclear cells in lavage fluid increased significantly 3 days after the LAR. Ten days after the LAR in the sensitized group (n = 8), as airway reactivity returned towards baseline, so did the cells in lavage. We conclude that increased airway reactivity to histamine is temporally associated with pulmonary inflammation as defined by cells in lavage after the LAR in this model.

Measles control in Yaounde: justification of a one dose, nine month minimum age vaccination policy in tropical Africa

For tropical countries the World Health Organisation recommends a single dose of measles vaccine, administered at a minimum age of 9 months. In some African nations, however, up to 26% of all reported measles occurs before the age of 9 months, and many African nations have been reluctant to follow the WHO recommendation. In 1974 the Ministry of Health of the United Republic of Cameroon made several changes in the existing measles control strategy, including increasing the minimum age for measles vaccination from 6 to 9 months. Surveillance of measles in Yaounde, the capital city, during the five years after the increase in age at vaccination did not reveal a need to return to the minimum age of 6 months. In fact, by 1979, with measles vaccination coverage among children 12-23 months of age at 40%, there had been a 44% decrease in reported measles among children of all ages, including a 64% decrease in the measles attack rate among children under the age of 9 months. These observations support the one dose, 9 month minimum age measles vaccination policy in tropical Africa.

Assessing The Discriminant Validity Of Regression Models And Subjectively Weighted Models Of Judgments

When either regression models or subjectively weighted models are used as aids in making placement decisions, the discriminant validity of these models is of interest. When all predictor information is used in all decisions, models which assign equal weights cannot simultaneously show high levels of predictive accuracy and discriminant validity; in some settings, both regression models and subjectively weighted models may. The discriminant validity of regression models and of subjectively weighted models was investigated in two judgment experiments. Both types of models showed high levels of accuracy and cross-validity in both experiments. Regression models showed discriminant validity in both experiments, while subjectively weighted models failed to show discriminant validity in the second. The homogeneity of cue validities appeared to moderate both the level of discriminant validity and the relationship between similarity of subjective models, across tasks, and discriminant validity.