Gluten induces rapid reprogramming of natural memory αβ and γδ intraepithelial T cells to induce cytotoxicity in celiac disease

Celiac disease (CD) is an autoimmune disease in which intestinal inflammation is induced by dietary gluten. The means through which gluten-specific CD4+ T cell activation culminates in intraepithelial T cell (T-IEL)-mediated intestinal damage remain unclear. Here, we performed multiplexed single-cell analysis of intestinal and gluten-induced peripheral blood T cells from patients in different CD states and healthy controls. Untreated, active, and potential CD were associated with an enrichment of activated intestinal T cell populations, including CD4+ follicular T helper (TFH) cells, regulatory T cells (Tregs), and natural CD8+ αβ and γδ T-IELs. Natural CD8+ αβ and γδ T-IELs expressing activating natural killer cell receptors (NKRs) exhibited a distinct TCR repertoire in CD and persisted in patients on a gluten-free diet without intestinal inflammation. Our data further show that NKR-expressing cytotoxic cells, which appear to mediate intestinal damage in CD, arise from a distinct NKR-expressing memory population of T-IELs. After gluten ingestion, both αβ and γδ T cell clones from this memory population of T-IELs circulated systemically along with gluten-specific CD4+ T cells and assumed a cytotoxic and activating NKR-expressing phenotype. Collectively, these findings suggest that cytotoxic T cells in CD are rapidly mobilized in parallel with gluten-specific CD4+ T cells after gluten ingestion.

Re-convolving the compositional landscape of primary and recurrent glioblastoma reveals prognostic and targetable tissue states

Glioblastoma (GBM) diffusely infiltrates the brain and intermingles with non-neoplastic brain cells, including astrocytes, neurons and microglia/myeloid cells. This complex mixture of cell types forms the biological context for therapeutic response and tumor recurrence. We used single-nucleus RNA sequencing and spatial transcriptomics to determine the cellular composition and transcriptional states in primary and recurrent glioma and identified three compositional 'tissue-states' defined by cohabitation patterns between specific subpopulations of neoplastic and non-neoplastic brain cells. These tissue-states correlated with radiographic, histopathologic, and prognostic features and were enriched in distinct metabolic pathways. Fatty acid biosynthesis was enriched in the tissue-state defined by the cohabitation of astrocyte-like/mesenchymal glioma cells, reactive astrocytes, and macrophages, and was associated with recurrent GBM and shorter survival. Treating acute slices of GBM with a fatty acid synthesis inhibitor depleted the transcriptional signature of this pernicious tissue-state. These findings point to therapies that target interdependencies in the GBM microenvironment.

Abstract 3165: Elucidation and pharmacological targeting of master regulator proteins representing mechanistic determinants of breast cancer stem-like tumor initiating cell state

Although breast cancer Stem-Like Tumor Initiating Cells (SLTIC) represent only a minute fraction of the total tumor mass, they are resistant to standard of care treatment and play a key role in tumor initiation, maintenance, and progression. Unequivocal SLTIC isolation, using surface markers, has proven highly elusive, thus impeding characterization and targeting of their mechanistic dependencies. To address this challenge, we applied a systems biology approach to effectively characterize SLTIC biology and to prioritize drugs that can reprogram them to a more differentiated state that is sensitive to chemotherapy.

To isolate breast cancer cells enriched for SLTICs, we performed flow cytometry-based sorting of tumor cells from 7 metastatic breast cancer patients, based on the expression of Epcam and CD49F, which are established epithelial and SLTIC-enriched cell markers, respectively. Activity-based clustering of single cell RNASeq profiles using the VIPER (Alvarez et al. Nat Genet 2017) algorithm identified two cell states, comprising cells presenting high activity of either SLTIC (i.e., BMI1, NOTCH1, etc.) or differentiated, proliferative epithelial cell markers (i.e., PCNA, CCNB1, etc.). Analysis of RNASeq profiles of BT20 cells treated with ~400 FDA approved and late-stage experimental drugs identified albendazole as the drug inducing the most significant activity inversion of SLTIC Master Regulator proteins (Alvarez et al. Nat Genet 2018) (p=4.21x10-5). This was experimentally confirmed in vivo by single cell analysis of metastatic TNBC PDX models at 14 days after treatment with albendazole, paclitaxel (a drug known to kill differentiated but not SLTIC cells), and vehicle control. As expected, paclitaxel induced dramatic decrease of the differentiated vs. SLTIC cell ratio, while albendazole had the opposite effect, inducing equally dramatic increase in that ratio, as assessed by a combination of CytoTRACE and established SLTIC marker analysis. Sequential therapy, based on a 30-day treatment with albendazole with 3 rounds of paclitaxel at day 15, 22, and 30, repeated after a 15-day drug holiday produced highly synergistic tumor volume reduction, compared to individual monotherapies (p=0.00869 by Bliss independence analysis). Indeed, while albendazole had little effect compared to vehicle control, as monotherapy, it induced >50% additional tumor viability reduction when combined with paclitaxel. The approach is highly generalizable and can be used to identify potential combination therapy approaches for any tumor in which molecular distinct subpopulations co-exist with different drug sensitivities, thus offering a practical solution to addressing tumor heterogeneity.

Citation Format: Jeremy Worley, Hongxu Ding, Heeju Noh, Evan Paull, Aaron T. Griffin, Adina Grunn, Daoqi You, Kristina Guillan, Erin Bush, Piero Dalerba, Peter Sims, Filemon S. Dela Cruz, Andrew L. Kung, Andrea Califano. Elucidation and pharmacological targeting of master regulator proteins representing mechanistic determinants of breast cancer stem-like tumor initiating cell state [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3165.

Critical and Creative Thinking and Photovoice: Strategies for Strengthening Participation and Inclusion

Researchers, nonprofit organizations, and others have long used photovoice as a participatory action research method with vulnerable groups to depict, reflect on, and describe their realities, and advocate for change. Paulo Freire, whose scholarship is a foundation of photovoice, encouraged critical thinking in a popular education process to understand "the 'why' of things and facts." Creative thinking, a complementary concept that emerged in the field of education in the 1990s, involves, at its core, development, implementation, and communication of multiple original ideas. We provide a model of critical and creative thinking as an integrated process that generates knowledge as participants complete four key photovoice steps: (1) answer questions with a camera, (2) communicate in the group, (3) observe commonalities, and (4) communicate to power. We argue that each step involves teachable skills and provide practical, low-tech strategies that photovoice facilitators can use to enhance critical and creative thinking by any participant who finds it challenging to complete the four steps. Bringing a critical and creative thinking process to photovoice facilitation grounds the method in its education roots. It can enhance participation and inclusion of any vulnerable group, including people with cognitive and communication disorders due to acquired brain injury, mental illness, or substance use disorder for example. We suggest that use of the suggested strategies will result in an authentic, meaningful process that helps equalize power relationships, respects individuals as experts on their own lives, and increases the potential for data that prompt action.

Coordinated speech therapy, physiotherapy, and pharmaceutical care telehealth for people with Parkinson disease in rural communities: an exploratory, 8-week cohort study for feasibility, safety, and signal of efficacy

INTRODUCTION

The potential for coordinated, multidisciplinary telehealth to help connect people with Parkinson disease (PD) in rural areas to PD specialists is crucial in optimizing care. Therefore, this study aimed to test the feasibility, safety, and signal of efficacy of a coordinated telehealth program, consisting of speech therapy, physiotherapy, and pharmaceutical care, for people with PD living in some rural US communities.

METHODS

Fifteen individuals with PD living in rural Wyoming and Nevada, USA, participated in this single-cohort, 8-week pilot study. Participants were assessed before and after 8 weeks of coordinated, one-on-one telehealth using the following outcomes: (1) feasibility: session attendance and withdrawal rate; (2) safety: adverse events; and (3) signal of efficacy: Communication Effectiveness Survey, acoustic data (intensity, duration, work (intensity times duration)), Parkinson's Fatigue Scale, 30 second Sit-to-Stand test, Parkinson's Disease Questionnaire - 39, Movement Disorder Society Unified Parkinson's Disease Rating Scale - Part III, and medication adherence.

RESULTS

Average attendance was greater than 85% for all participants. There were no serious adverse events and only nine minor events during treatment sessions (0.9% of all treatment sessions had a participant report of an adverse event); all nine cases resolved without medical attention. Although 14 of 16 outcomes had effect sizes trending in the direction of improvement, only two were statistically significant using non-parametric analyses: 30 second Sit-to-Stand (pre-test median=11.0 (interquartile range (IQR)=6.0); post-test median=12.0 (IQR=3.0) and acoustic data work (pre-test median=756.0 dB s (IQR=198.4); post-test median=876.3 dB s (IQR=455.5), p<0.05.

CONCLUSION

A coordinated, multidisciplinary telehealth program was safe and feasible for people in rural communities who have PD. This telehealth program also yielded a signal of efficacy for most of the outcomes measured in the study.

Describing the Composition of Individualized Education Plans for Students With Traumatic Brain Injury

Purpose The purpose of this study was to explore and describe the features of Individualized Education Plans (IEPs) for a cohort of students with traumatic brain injury (TBI) to help elucidate current special education practices for students with TBI. Method We obtained permission from administrators of a local school district of 41,000 students in a Midwestern state to review de-identified IEP records of students verified with TBI. We examined demographic information (i.e., cause and age at time of injury), IEP services and intensity, IEP goal categories, and previous verification status. Results Descriptive results support that intervention services were more intense for students with TBI with greater lengths of time postinjury. Target behaviors within goals were more often related to math and reading than to the cognitive processes that govern these skills, such as attention, memory, and executive functioning. Finally, more than a third of our sample had been verified with a disability and were receiving special education services via an IEP prior to their TBI. Conclusions This work represents an important first step in understanding the special education services for students with TBI. Future research should explore interventions that are ecologically valid for school-based settings and are developed to address the idiosyncratic deficits of students with TBI, particularly interventions that focus on the underlying cognitive processes experienced by these students.

Dissecting Human Tissue Resident Memory T cell Heterogeneity on the Single Cell Level

The majority of T cells throughout the human body persist as non-circulating tissue-resident memory T cells (TRM) in lymphoid and mucosal sites, and are vital for orchestrating protective immune responses. However, given the difficulty of sampling healthy human tissues, a full understanding of TRM identity and function across tissue sites remains lacking. Here, we utilize a unique human tissue resource where tissues are obtained from organ donors to dissect CD4+ and CD8+ TRM heterogeneity using high-dimensional flow cytometry and single cell RNA-sequencing (scRNA-seq). We identify remarkable heterogeneity in expression of key surface markers that define TRM, namely CD103, CD101, CD49a, PD-1 and CXCR6, particularly in the lung and the intestines. These phenotypic groups of TRM denote different functional subsets after activation: CD103+ and CD101+ TRM preferentially produce IL-17A, CD49a+ and CXCR6+ TRM show enhanced IFNγ production, and PD-1+ TRM produce granzyme-B. To investigate the transcriptional programming underlying TRM, we profile ~20,000 resting and activated T cells from the lungs and intestines of human organ donors with scRNA-seq and identify TRM based on our previously defined tissue signature. In both tissues, we detect multiple clusters of TRM enriched for expression of individual or a combination of TRM marker genes. Importantly, these clusters show variable expression of genes coding for cytokines (IFNG, IL23A, IL26), transcription factors (TBX21, GATA3, BATF), and cytotoxic molecules (GNLY, GZMs), suggesting differentially regulated TRM subsets. Our results therefore highlight the heterogeneity of TRM across human tissue sites and define the transcriptional programming underlying TRM function.

Generation and persistence of human tissue-resident memory T cells in lung transplantation

Tissue-resident memory T cells (T_RM) maintain immunity in diverse sites as determined in mouse models, whereas their establishment and role in human tissues have been difficult to assess. Here, we investigated human lung T_RM generation, maintenance, and function in airway samples obtained longitudinally from human leukocyte antigen (HLA)-disparate lung transplant recipients, where donor and recipient T cells could be localized and tracked over time. Donor T cells persist specifically in the lungs (and not blood) of transplant recipients and express high levels of T_RM signature markers including CD69, CD103, and CD49a, whereas lung-infiltrating recipient T cells gradually acquire T_RM phenotypes over months in vivo. Single-cell transcriptome profiling of airway T cells reveals that donor T cells comprise two T_RM-like subsets with varying levels of expression of T_RM-associated genes, whereas recipient T cells comprised non-T_RM and similar T_RM-like subpopulations, suggesting de novo T_RM generation. Transplant recipients exhibiting higher frequencies of persisting donor T_RM experienced fewer adverse clinical events such as primary graft dysfunction and acute cellular rejection compared with recipients with low donor T_RM persistence, suggesting that monitoring T_RM dynamics could be clinically informative. Together, our results provide spatial and temporal insights into how human T_RM develop, function, persist, and affect tissue integrity within the complexities of lung transplantation.

Single cell RNA-Seq reveals pre-cDCs fate determined by transcription factor combinatorial dose

Background

Classic dendritic cells (cDCs) play a central role in the immune system by processing and presenting antigens to activate T cells, and consist of two major subsets: CD141⁺ cDC (cDC1) and CD1c⁺ cDC (cDC2). A population of migratory precursor cells, the pre-cDCs, is the immediate precursors to both cDC subsets. Previous studies showed that there were two pre-committed pre-cDC subpopulations. However, the key molecular drivers of pre-commitment in human pre-cDCs were not investigated.

Results

To identify the key molecular drivers for pre-commitment in human pre-cDCs, we performed single cell RNA sequencing (RNA-Seq) of two cDC subsets and pre-cDCs, and bulk RNA-Seq of pre-cDCs and cDCs from human peripheral blood. We found that pre-DC subpopulations cannot be separated by either variable genes within pre-cDCs or differentially expressed genes between cDC1 and cDC2. In contrast, they were separated by 16 transcription factors that are themselves differentially expressed or have regulated targets enriched in the differentially expressed genes between bulk cDC1 and cDC2, with one subpopulation close to cDC1 and the other close to cDC2. More importantly, these two pre-cDC sub-populations are correlated with ratio of IRF8 to IRF4 expression level more than their individual expression level. We also verified these findings using three recently published datasets.

Conclusions

In this study, we demonstrate that single cell transcriptome profiling can reveal pre-cDCs differentiation map, and our results suggest the concept that combinatorial dose of transcription factors determines cell differentiation fate.

Electronic supplementary material

The online version of this article (10.1186/s12860-019-0199-y) contains supplementary material, which is available to authorized users.

Mobilizing a Statewide Network to Provide Ebola Education and Support

BACKGROUND

Healthcare providers require the latest information and procedures when a public health emergency arises. During the fall of 2014, when the Ebola virus was first identified in a patient in the United States, education about Ebola virus disease (EVD) and procedures for its identification and control needed widespread and immediate dissemination to healthcare providers. In addition, there was a need to allay fears and reassure the public and providers that a process was in place to manage Ebola should it arrive in Arkansas. The state health department engaged multiple interest groups and provided a variety of educational and management activities. The Arkansas Department of Health and the only academic medical center in the state began offering time-consuming, one-on-one education over the phone, which reached too few providers. A solution was needed to educate many providers across the state in the protocols for identification, isolation, and management of patients with EVD. In response, the Arkansas Department of Health and the University of Arkansas for Medical Sciences leveraged the interactive video and Webinar capabilities of the state's telemedicine network to educate both providers and the public of this public health emergency.

MATERIALS AND METHODS

Six interactive video events were staged over 5 days in October 2014.

RESULTS

In six events, 82 individual healthcare facilities (67 of which were hospitals) and 378 providers attended via the Webinar option, whereas 323 healthcare professionals received continuing education credits.

CONCLUSIONS

A statewide videoconferencing infrastructure can be successfully mobilized to provide timely public health education and communication to healthcare providers and the public in multiple disciplines and practice settings.

Spinach latent virus Infecting Tomato in Virginia, United States

Plants in a single field of commercial tomato (Solanum lycopersicum) of unidentified cultivars in Virginia in July, 2012, were observed showing stunting, leaf distortion, twisting and thickening, discoloration, and color streaking and ringspots on fruits. Serological tests were negative for Cucumber mosaic virus, Groundnut ringspot virus, Tomato spotted wilt virus, Tomato chlorotic spot virus, Impatiens necrotic spot virus, Tobacco mosaic virus, and Tomato bushy stunt virus (Agdia, Inc., Elkhart, IN). Using a membrane-based macroarray (3), hybridization was observed to 8 of 9 70-mer oligonucleotide probes of Spinach latent virus (SpLV; genus Ilarvirus, family Bromoviridae). To confirm the hybridization results, complementary DNA (cDNA) was synthesized using random hexamers and MMLV reverse transcriptase (Promega, Madison, WI), followed by PCR amplification using ilarvirus degenerate primers (4). Fragments of approximately 380 bp were amplified and directly sequenced (GenBank Accession KC_466090); a BLAST search showed a 99% identity to the SpLV RNA 2 reference genome (NC_003809). Primers for SpLV RNA1 (SpLVRNA1f-GGTGTCACCATGCAAACTGG, SpLVRNA1r-AGCTCTTCGTAATAGGCCTGC) and SpLV RNA3 (SpLVCPf-GAAGTCTTTCCCAGGTGAGCA, SpLVCPr-AGGTGGGCATATGGACTTGG) were designed and cDNA was amplified using the IQ supermix (Biorad, Hercules, CA) with thermocycling of 94°C for 4 min, 35× (94°C 45 s, 55°C 45 s, 72°C 45 s), and 72°C for 10 min. The resulting fragments of 538 bp for RNA1 (KC_466088) and 661 bp for RNA3 (KC_466089) showed 100% identity to reference genome sequences for SpLV (NC_003808 and NC_003810, respectively). To demonstrate virus transmissibility, Chenopodium quinoa plants were mechanically inoculated using tomato leaf material (same source described above) ground in 30 mM Na₂HPO₄ buffer, pH 7.0. Necrotic spots developed on the inoculated leaves 10 dpi. Younger, non-inoculated leaves showed yellow mottling and tested positive for SpLV by RT-PCR (two of two plants tested). The detection of SpLV is rarely reported, with only one record from the United States (2). Although SpLV is described as a latent virus, it has been found associated with tomato fruit symptoms in New Zealand (1). It is not known if the fruit ringspot and other symptoms on the Virginia samples were due to virus infection. Since SpLV is seed-transmissible and seed production takes place in different parts of the world, it has the potential to spread with germplasm and become more widespread in North America. References: (1) B. S. M. Lebas et al. Plant Dis. 91:228, 2007. (2) H. Y. Liu and J. E. Duffus. Phytopathology 76:1087, 1986. (3) K. L. Perry and X. Lu. Phytopathology 100:S100, 2010. (4) M. Untiveros, et al. J. Virol. Methods 165:97, 2010.

First Report of Puccinia emaculata Infection on Switchgrass in Virginia

During the spring of 2007, approximately 2,000 switchgrass plants, representing 168 core switchgrass germplasm, were established in a field nursery at the Virginia Tech Kentland Farm Research Center in Montgomery County, VA. These germplasms were originally obtained from the USDA Plant Genetic Resources Conservation Unit (Griffin, GA) and included both lowland and upland ecotypes. After planting, the switchgrass plants were allowed to establish for 3 years. In the summers of 2009, 2010, and 2011, a substantial infection of a foliar rust pathogen was observed on more than 90% of switchgrass lines in the field. The infected leaves had dark brown pustules that were arranged in a linear fashion between the veins and mainly located on the adaxial surface of the leaf. We observed the infected leaf samples under a microscope and isolated the urediniospores. The urediniospores were brown, round, and averaged 26.08 ± 1.67 μm long and 24.65 ± 1.66 μm wide. Teliospores were observed late in the summers of 2009 and 2010. The teliospores were two-celled, oblong to ellipsoid in shape, and averaged 32.23 ± 3.07 μm in length. The apical cell width averaged 17.6 ± 1.83 μm and the basal cell width averaged 15.08 ± 1.75 μm. The morphology of both the urediniospores and teliospores were similar to Puccinia emaculata Schw. (P. emaculata) (2,3). Using previously established rust disease scoring methods (1), the infected switchgrass lines were evaluated and scored for infection severity on a 0 to 9 scale based on the percentage of leaf area infected, with 0 being either highly resistant or escaping infection and 9 being highly susceptible. The majority of upland switchgrass cultivars, including Caddo, Cave-in-rock, Blackwell, Sunburst, Pathfinder, and Dacotah, were moderately to highly susceptible to this rust pathogen and on average, scored between 7 and 8. However, the majority of lowland switchgrass cultivars, including Alamo, Kanlow, TEM-SEC, TEM-SLC, and TEM-LoDorm, were moderately to highly resistant and scored on average between 3 and 4. This result is consistent with previous reports that show that lowland ecotypes are more resistant to rust diseases (1). To further validate the identity of the rust pathogen, we designed two primers (5'-CCAGTAACGGCGAGTGAAGAG-3' and 5'-CGACTTCCATGGCCACCGTGCGGCTGTCT-3') based on the 18S rDNA sequence of P. emaculata (3). DNA was extracted from bulk infected leaf material for PCR amplification. The 1.2 kb PCR product was isolated and sent for DNA sequencing. The DNA sequence was 98% identical to the 18S rDNA sequence of P. emaculata (EU915294.1). To our knowledge, this study represents the first report of rust on a wide range of various switchgrass cultivars in Virginia. References: (1) D. M. Gustafson et al. Crop Sci. 43:755, 2003. (2) R. L. Hirsch et al. Plant Dis. 94:381, 2010. (3) J. Zale et al. Plant Dis. 92:1710, 2008.

A Tetracycline-Repressible Transactivator System to Study Essential Genes in Malaria Parasites

A major obstacle in analyzing gene function in apicomplexan parasites is the absence of a practical regulatable expression system. Here, we identified functional transcriptional activation domains within Apicomplexan AP2 (ApiAP2) family transcription factors. These ApiAP2 transactivation domains were validated in blood-, liver-, and mosquito-stage parasites and used to create a robust conditional expression system for stage-specific, tetracycline-dependent gene regulation in Toxoplasma gondii, Plasmodium berghei, and Plasmodium falciparum. To demonstrate the utility of this system, we created conditional knockdowns of two essential P. berghei genes: profilin (PRF), a protein implicated in parasite invasion, and N-myristoyltransferase (NMT), which catalyzes protein acylation. Tetracycline-induced repression of PRF and NMT expression resulted in a dramatic reduction in parasite viability. This efficient regulatable system will allow for the functional characterization of essential proteins that are found in these important parasites.

An evaluation of scrapie surveillance in the United States

Animal health surveillance systems should reflect national disease control priorities and promote the best use of public resources by maximizing effectiveness and efficiency. A surveillance system should be routinely evaluated to assess the degree to which the system accomplishes these goals, fulfills its stated objectives, and meets accepted surveillance standards. In the United States, there are a number of disparate endemic disease surveillance and eradication programs. The National Animal Health Surveillance System is a federal initiative designed to combine animal health surveillance and monitoring activities into a comprehensive and coordinated system. A protocol has been developed to facilitate the evaluation of animal health surveillance systems and investigate opportunities for coordination between the different surveillance and eradication programs. The evaluation protocol was based largely on protocols developed for public health but adapted for the specific needs and goals of animal health surveillance. The evaluation process was designed to identify program strengths and areas for improvement and facilitate the system's adaptability to changing situations. The evaluation protocol was applied to the scrapie surveillance system in the United States; scrapie surveillance was found to be an important part of surveillance for transmissible spongiform encephalopathies. Results from the evaluation of sensitivity, sampling methods and representativeness are presented.

Application of broken-line analysis to assess floor space requirements of nursery and grower-finisher pigs expressed on an allometric basis1

Few issues in swine production are as complex as floor space allowances. One method for pork producers to calculate floor space allowance (A) is to convert BW into a 2-dimensional concept yielding an expression of A = k * BW(0.667). Data on ADG, ADFI, and G:F were obtained from published peer-reviewed studies. Five data sets were created: A = grower-finisher pigs, fully slatted floors, and consistent group size; B = grower-finisher pigs and fully slatted floors (group size did not need to be consistent); C = grower-finisher pigs, partially slatted floors, and consistent group size; D = grower-finisher pigs, partially slatted floors (group size did not need to be consistent); and E = nursery pigs, fully slatted or woven wire floors (group size did not need to be consistent). Each data set was analyzed using a broken-line analysis and a linear regression. For the broken-line analyses, the critical k value, below which a decrease in ADG occurred, varied from 0.0317 to 0.0348. In all cases the effect of space allowance on ADG was significant (P < 0.05). Using the linear analyses based on data with k values of < 0.030, the critical k values for the 4 grower-finisher data sets did not differ from those obtained using the broken-line analysis (0.0358 vs. 0.0336, respectively; P > 0.10); however, none of the linear regressions explained a significant proportion of the variation in ADG. The slopes for the nonplateau portion of the broken-line analyses based on percent values varied among data sets. For every 0.001 decrease in k (approximately 3% of the critical k value), ADG decreased by 0.56 to 1.41%, with an average value of 0.98% for the 5%-based analyses. The use of an allometric approach to express space allowance and broken-line analysis to establish space requirements seem to be useful tools for pig production. The critical k value at which crowding becomes detrimental to the growth of the pig is similar in full- and partial-slat systems and in nursery and grower-finisher stages. The critical point for crowding determined in these analyses approximated current recommendations to ensure the welfare of pigs.

Insulin-sensitizing effect of rosiglitazone (BRL-49653) by regulation of glucose transporters in muscle and fat of Zucker rats

Thiazolidinediones (TZDs), a class of antidiabetic agents, are specific agonists of peroxisome proliferator activator receptor (PPARgamma). However, their mechanisms of action, and the in vivo target tissues that mediate insulin sensitization are not well understood. The aim of this study was to investigate the role of glucose transporters (GLUT-1 and GLUT-4) in the TZD insulin-sensitizer action. The effects of rosiglitazone treatment were studied using Zucker (fa/fa) rats after 7 days of oral dosing (3.6 mg/kg/d). Rosiglitazone lowered (approximate 80%) basal plasma insulin levels in obese rats and substantially corrected (approximately 50%) insulin resistance based upon results from hyperinsulinemic euglycemic clamp studies. GLUT-4 protein levels were reduced (approximately 75%) in adipose tissue of obese rats and treatment with rosiglitazone normalized them. Interestingly, GLUT-1 protein content was increased in adipose tissue ( thick approximate 150%) and skeletal muscle (approximately 50%) of obese rats and treatment with rosiglitazone increased it even more by 5.5-fold in fat and by 2.5-fold in muscle. Consistent with these results, basal (GLUT-1-mediated) transport rate of 3-O-methyl-D-glucose into isolated epitrochlearis muscle was elevated in response to rosiglitazone. Incubation of fully differentiated 3T3-L1 adipocytes with the drug for 7 days increased the levels of GLUT-1 protein, but did not affect GLUT-4 levels. In conclusion, rosiglitazone may improve insulin resistance in vivo by normalizing GLUT-4 protein content in adipose tissue and increasing GLUT-1 in skeletal muscle and fat. While the drug has a direct effect on GLUT-1 protein expression in vitro without a direct effect on GLUT-4 suggests that direct and indirect effects of rosiglitazone on glucose transporters may have an important role in improving insulin resistance in vivo.

The use of human touch to improve the well-being of older adults. A holistic nursing intervention

Touch and massage are viable nursing modalities that are both underutilized and understudied. This underuse of touch is especially noted in settings aimed at improving the well-being of older adults. A number of studies suggest that the appropriate use of touch by nurses has the potential to significantly improve the health status of older adults. In particular, touch can be useful with cognitively impaired, institutionalized, or hospitalized older adults. Likewise, touch can be useful for improving comfort and communication among terminally ill older adults and their loved ones. This article synthesizes some of the available literature on the subject while suggesting avenues for nursing practice and education aimed at using touch as a viable and cost-effective holistic gerontological nursing intervention.

Psychological and physiological factors associated with tilt table testing for neurally mediated syncopal syndromes

This study investigated psychological and physiological factors in two groups of patients who had tilt table testing for autonomic dysfunction. The first group of 61 patients completed assessments of depression, anxiety, and symptom effects on lifestyle. The 25 patients identified as tilt positive were younger (30.5 years) and had higher mean depression scores (7.6) compared to the tilt-negative response group (n = 36); the latter averaged 40 years of age and had mean depression scores of 4.6. These differences were statistically significant. Women testing tilt positive were significantly more depressed than tilt-negative women (P = 0.02). More severe depressive symptoms were associated with lower blood pressure (BP) (P < 0.05). A second group of 52 patients was monitored during tilt for BP, heart rate (HR), skin temperature (TEMP), skin conductance level (SCL), and forehead muscle tension (EMG). Twenty-seven tested positive and 23 were negative. There were statistically significant group differences in systolic BP and diastolic BP (P < 0.05). There was a significant interaction between tilt status (positive or negative) and time (P = 0.03) in HR. TEMP increased 2 degrees over time in both groups (P < 0.05). The decrease in SCL from 13.7 to 10.4 mu omega in the tilt-positive response group compared to the slight increase in the tilt-negative group was significantly different (P < 0.05). Identification of psychological factors correlated with BP and physiological changes that accompany decreases in BP in tilt-positive response patients could guide management of patients with autonomic dysfunction.

CC chemokine receptor 2 is required for macrophage infiltration and vascular hypertrophy in angiotensin II-induced hypertension

Recent studies have identified the presence of macrophages in the arterial wall of hypertensive animals and suggested that as is the case in atherosclerosis, macrophage products may be important mediators of the adaptive response of the arterial wall. In support of this, we have previously shown that the expression of monocyte chemoattractant protein-1 is upregulated in the arteries of hypertensive animals. We hypothesized that macrophage recruitment is a critical step in the pathogenesis of hypertension. To obtain insights into this potential mechanism, we made use of mice deficient in the CC chemokine receptor 2 (CCR2), the receptor for monocyte chemoattractant protein-1. Hypertension was induced with the subcutaneous administration of angiotensin II (0.75 mg. kg(-1). d(-1)) for 7 days. Using in situ hybridization with a probe for c-fms to identify macrophages, we found that hypertension-induced macrophage infiltration of the arterial wall was virtually eliminated in CCR2-deficient mice. In addition, vascular hypertrophy was reduced by approximately 65% compared with wild-type animals. These data demonstrate that CCR2 is essential for the recruitment of macrophages into the arterial wall in the setting of hypertension. Furthermore, the decreased hypertrophic response suggests that vascular hypertrophy occurs in part as a consequence of macrophage infiltration. In angiotensin II-induced hypertension, CCR2-mediated responses are critical to the process of macrophage recruitment and vascular hypertrophy and may represent one mechanism by which at least some forms of hypertension may lead to the development of atherosclerosis.

A human capecitabine excretion balance and pharmacokinetic study after administration of a single oral dose of 14C-labelled drug

An excretion balance and pharmacokinetic study was conducted in cancer patients with solid tumors who received a single oral dose of capecitabine of 2000 mg including 50 microCi of 14C-radiolabelled capecitabine. Blood, urine and fecal samples were collected until radioactive counts had fallen to below 50 dpm/mL in urine, and levels of intact drug and its metabolites were measured in plasma and urine by LC/MS-MS (mass spectrometry) and 19F-NMR (nuclear magnetic resonance) respectively. Based on the results of the 6 eligible patients enrolled, the dose was almost completely recovered in the urine (mean 95.5%, range 86-104% based on radioactivity measurements) over a period of 7 days after drug administration. Of this, 84% (range 71-95) was recovered in the first 12 hours. Over this time period, 2.64% (0.69-7.0) was collected in the feces. Over a collection period of 24-48 h, a total of 84.2% (range 80-95) was recovered in the urine as the sum of the parent drug and measured metabolites (5'-DFCR, 5'-DFUR, 5-FU, FUH2, FUPA, FBAL). Based on the radioactivity measurements of drug-related material, absorption is rapid (tmax 0.25-1.5 hours) followed by a rapid biphasic decline. The parent drug is rapidly converted to 5-FU, which is present in low levels due to the rapid metabolism to FBAL, which has the longest half-life. There is a good correlation between the levels of radioactivity in the plasma and the levels of intact drug and the metabolites, suggesting that these represent the most abundant metabolites of capecitabine. The absorption of capecitabine is rapid and almost complete. The excretion of the intact drug and its metabolites is rapid and almost exclusively in the urine.

Bioequivalence of two tablet formulations of capecitabine and exploration of age, gender, body surface area, and creatinine clearance as factors influencing systemic exposure in cancer patients

PURPOSE

The objective of the study was to assess the bioequivalence of two tablet formulations of capecitabine and to explore the effect of age, gender, body surface area and creatinine clearance on the systemic exposure to capecitabine and its metabolites.

METHODS

The study was designed as an open, randomized two-way crossover trial. A single oral dose of 2000 mg capecitabine was administered on two separate days to 25 patients with solid tumors. On one day, the patients received four 500-mg tablets of formulation B (test formulation) and on the other day, four 500-mg tablets of formulation A (reference formulation). The washout period between the two administrations was between 2 and 8 days. After each administration, serial blood and urine samples were collected for up to 12 and 24 h, respectively. Unchanged capecitabine and its metabolites were determined in plasma using LC/MS-MS and in urine by NMRS.

RESULTS

Based on the primary pharmacokinetic parameter, AUC(0-infinity) of 5'-DFUR, equivalence was concluded for the two formulations, since the 90% confidence interval of the estimate of formulation B relative to formulation A of 97% to 107% was within the acceptance region 80% to 125%. There was no clinically significant difference between the t(max) for the two formulations (median 2.1 versus 2.0 h). The estimate for C(max) was 111% for formulation B compared to formulation A and the 90% confidence interval of 95% to 136% was within the reference region 70% to 143%. Overall, these results suggest no relevant difference between the two formulations regarding the extent to which 5'-DFUR reached the systemic circulation and the rate at which 5'-DFUR appeared in the systemic circulation. The overall urinary excretions were 86.0% and 86.5% of the dose, respectively, and the proportion recovered as each metabolite was similar for the two formulations. The majority of the dose was excreted as FBAL (61.5% and 60.3%), all other chemical species making a minor contribution. Univariate and multivariate regression analysis to explore the influence of age, gender, body surface area and creatinine clearance on the log-transformed pharmacokinetic parameters AUC(0-infinity) and C(max) of capecitabine and its metabolites revealed no clinically significant effects. The only statistically significant results were obtained for AUC(0-infinity) and C(max) of intact drug and for C(max) of FBAL, which were higher in females than in males.

CONCLUSION

The bioavailability of 5'-DFUR in the systemic circulation was practically identical after administration of the two tablet formulations. Therefore, the two formulations can be regarded as bioequivalent. The variables investigated (age, gender, body surface area, and creatinine clearance) had no clinically significant effect on the pharmacokinetics of capecitabine or its metabolites.

Hearing our voices: assessing HIV prevention needs among Asian and Pacific Islander women

The purpose of this study was to (a) assess the impact of HIV/AIDS on the Asian-Pacific Islander (API) community and changes in their behavior due to AIDS, (b) identify perception of risk, HIV risk behaviors, factors contributing to those behaviors, barriers to HIV prevention, and the types of prevention programs that would benefit their community, and (c) describe culturally appropriate considerations when designing HIV prevention strategies for API women. Thirty API adults participated in three different groups. Focus group interviewing methods were used, guided by the Health Belief Model. The women had numerous concerns about HIV that placed them at risk for infection, such as their inability to talk with their sexual partners about condom use due to the cultural and taboo nature of sexual topics. All groups concluded that for HIV prevention interventions to be successful, they must be tailored to the cultural and specific needs of API women.

Seroprevalence of Trichinella infection in domestic swine based on the National Animal Health Monitoring System's 1990 and 1995 swine surveys

Swine sera collected by the US Department of Agriculture's Center for Animal Health Monitoring during 1990 and 1995 was tested for antibodies to Trichinella spiralis using an enzyme immunoassay. From a total of 3048 sera collected from lactating sows in 1990, five sera tested positive for a prevalence of 0.16%. From a total of 7987 sera collected from both finishing pigs and gestating sows in 1995, one serum was positive for a prevalence of 0.013%. Responses to questionnaires administered at the time of serum collection showed that seropositive farms had management variables consistent with known risk factors for exposure to trichinae.

Practice what we preach? HIV knowledge, beliefs, and behaviors of adolescents and adolescent peer educators

The purpose of this article is to (a) describe the knowledge, beliefs, and sexual behaviors of urban adolescents and adolescent peer educators, and (b) identify elements needed to design effective HIV/AIDS prevention programs for out-of-school youth. Thirty-three predominantly African American adolescents (female = 14; male = 19) between the ages of 14 and 24 in a large urban city including adolescent (n = 18) and adolescent peer educators (n = 15) participated. Paper-and-pencil questionnaire and focus-group interviewing methods were used. Adolescents and adolescent peer educators had a moderately high level of HIV knowledge, confidence in their ability to use condoms, and beliefs that condom use would not decrease sexual pleasure or imply infidelity. Both groups reported low perceptions of susceptibility of HIV infection. Engagement in sexual risk behavior was low, but was significantly higher among males. Although adolescent male peer educators engaged in a higher frequency of risk behaviors over time, they had a lower frequency of sexual risk behaviors in the past 2 months compared with male adolescents. Study findings showed that HIV prevention interventions need to include information about specific risk behaviors, such as using condoms for oral sex, and cleaning drug paraphernalia. Community-based and church programs, visible HIV prevention messages, specifically those aimed at increasing perceptions of HIV risk, and the development of condom-use skills were identified by adolescents and adolescent peer educators as relevant approaches to reduce HIV infection among this population.

Preadolescent suicidal behavior: the role of cognitive functioning

The recent suicidal behavior of fifty-three hospitalized preadolescents was assessed in interviews with children and their parents. Children described by their parents as more suicidal scored higher on measures of verbal intelligence and language production than their less suicidal counterparts, with unique variance predicted only by language production ability. The results suggest that parents of preadolescents with better language production skills may be more aware of their youngsters' suicidal thoughts than parents of children with poorer language production ability.

Plasma kinetics of vitamin A in humans after a single oral dose of [8,9,19-13C]retinyl palmitate

The kinetics of vitamin A and its major metabolites were investigated in humans. Eleven healthy male subjects ingested 105 mumol (100,000 IU) of [8,9,19-13C]retinyl palmitate in an oily solution. Twenty-seven blood samples were collected during the 1-week study. Plasma samples were analyzed for retinyl esters and for [12C]- and [8,9,19-13C]retinol. Retinol isotopes were quantified using a newly developed GC-MS method. Total retinyl esters peaked at about 4.45 mumol/L from 3.5 to 12 h after dosing. As a result of the perturbation of the tracee system, the plasma concentration of [12C]retinol increased and then decreased as the concentration of [8,9,19-13C]retinol increased, indicating rapid distribution kinetics. A broad single peak (1.16 +/- 0.32 mumol/L) was observed for [8,9,19-13C]retinol at about 10 to 24 h postdose; this likely reflects hepatic secretion of [8,9,19-13C]retinol associated with retinol-binding protein. Then, declining levels of the tracer and increasing levels of the tracee were observed. At its peak, the ingested [8,9,19-13C]retinol reached about 51% of the observed total plasma retinol concentration. This percentage dropped to 13.4% on day 7 indicating slow final elimination from plasma. Our data support the concept that the liver follows the principle "last in/first out' in maintaining vitamin A homeostasis.

Inhibition and kinetics of cytochrome P4503A activity in microsomes from rat, human, and cdna-expressed human cytochrome P450

Midazolam (MDZ) is metabolized in human liver microsomes by the cytochrome P450 (CYP) 3A subfamily to 1'-hydroxy (1'-OH) and 4-hydroxy (4-OH) metabolites. MDZ is metabolized in the rat primarily to 4-OH MDZ, 1'-OH MDZ, and 1',4-dihydroxy (1',4-diOH) MDZ. The kinetics of 4-OH and 1'-OH metabolite formation were determined using hepatic microsomes from control, Ro 23-7637 and dexamethasone-treated male rats. KM values for the major metabolite, 4-OH MDZ, were 24.5, 43.1, and 32.8 microM, and the corresponding Vmax values were 5.9, 28.9, and 13 nmol/mg/min for the control, DEX, and Ro 23-7637-treated animals, respectively KM values for 1'-hydroxylation of MDZ (the major metabolite) after incubation with human liver microsomes from three individuals were 5.57, 2.50, and 3.56 microM, and the corresponding Vmax values were 4.38, 0.49, and 0.19 nmol/mg/min, respectively. In parallel studies using cDNA-expressed human CYP3A4 microsomes, the KM for 1'-OH formation was 1.56 microM, and the corresponding Vmax was 0.16 nmol/mg/min. MDZ was not metabolized by cDNA-expressed human CYP2D6, CYP2E1, or CYP1A2, thus confirming that these isoforms were not responsible for its biotransformation. The formation of 1',4-diOH metabolite in rat and 1'-OH formation in cDNA-expressed human CYP3A4 microsomes showed a decrease in velocity at high substrate concentrations. Inhibition studies showed that MDZ hydroxylation was strongly inhibited by ketoconazole and Ro 23-7637 in rat, human, and cDNA-expressed human CYP3A4 microsomes. alpha-Naphthoflavone stimulated 1'-OH metabolite formation in human and cDNA-expressed human CYP3A4 microsomes at low concentration (10 microM). Naringenin, a flavonoid present in grapefruit juice, also inhibited MDZ metabolism in human liver microsomes. Immunoinhibition studies revealed that polyclonal anti-rat CYP3A2 antibody inhibited MDZ metabolism 80-90% in rat, human, and cDNA-expressed human CYP3A4 microsomes, thus suggesting that members of the CYP3A4 subfamily were involved in the metabolism.