Contrasting water-use strategies revealed by species-specific transpiration dynamics in the Caatinga dry forest

In forest ecosystems, transpiration (T) patterns are important for quantifying water and carbon fluxes and are major factors in predicting ecosystem change. Seasonal changes in rainfall and soil water content can alter the sensitivity of sap flux density to daily variations in vapor pressure deficit (VPD). This sensitivity is species-specific and is thought to be related to hydraulic strategies. The aim of this work is to better understand how the sap flux density of species with low versus high wood density differ in their sensitivity to VPD and soil water content and how potentially opposing water-use strategies influence T dynamics, and ultimately, correlations to evapotranspiration (ET). We use hysteresis area analysis to quantify the sensitivity of species-specific sap flux density to changes in the VPD, breakpoint-based models to determine the soil water content threshold instigating a T response and multiscalar wavelet coherency to correlate T to ET. We found that low wood density Commiphora leptophloeos (Mart.) Gillett had a more dynamic T pattern, a greater sensitivity to VPD at high soil water content, required a higher soil water content threshold for this sensitivity to be apparent, and had a significant coherency correlation with ET at daily to monthly timescales. This behavior is consistent with a drought avoidance strategy. High wood density Cenostigma pyramidale  (Tul.)  E. Gagnon & G. P. Lewis, conversely, had a more stable T pattern, responded to VPD across a range of soil water content, tolerated a lower soil water content threshold to T, and had a significant coherency correlation with ET at weekly timescales. This behavior is consistent with a drought-tolerant strategy. We build on previous research to show that these species have contrasting water-use strategies that should be considered in large-scale modeling efforts.

Alliance A022101: A Pragmatic Randomized Phase III Trial Evaluating Total Ablative Therapy for Patients with Limited Metastatic Colorectal Cancer - Evaluating Radiation, Ablation and Surgery (ERASur)

PURPOSE/OBJECTIVE(S)

For patients with oligometastatic colorectal cancer (CRC), aggressive local therapy of isolated metastases, particularly in the liver, has been associated with long-term progression-free survival and overall survival (OS) primarily based on retrospective evidence. However, in patients with limited metastatic CRC that is deemed inoperable or those with additional disease outside of the liver or lungs, the role of local ablative therapies, including microwave ablation (MWA) and stereotactic body radiation therapy (SBRT), to render patients disease free is less clear. Further, despite the long history of treating oligometastatic CRC with local therapy, which is provider biased and not evidence based, questions remain regarding the benefit of extending the paradigm of metastatic directed therapy to patients with more extensive disease. This trial seeks to use a pragmatic multimodality approach that mirrors the current clinical dilemma. This study is designed to evaluate the safety and efficacy of adding total ablative therapy (TAT) of all sites of disease to standard of care systemic treatment in those with limited metastatic CRC.

MATERIALS/METHODS

A022101 is a National Clinical Trials Network randomized phase III study planned to enroll 364 patients with newly diagnosed metastatic CRC (BRAF wild-type, microsatellite stable) with 4 or fewer sites of metastatic disease on baseline imaging. Liver-only metastatic disease is not permitted, and lesions must be amenable to any combination of surgical resection, MWA, and/or SBRT with SBRT required for at least one lesion. Patients receive first-line systemic therapy for 4-6 months and are then randomized 1:1, stratified by number of metastatic organ sites (1-2 vs. 3-4), timing of metastatic disease diagnosis (de novo vs. secondary), and presence of metastatic disease outside the liver and lungs in at least one site. Patients in Arm 1 will receive TAT which consists of treatment of all metastatic sites with SBRT ± MWA ± surgical resection followed by standard of care systemic therapy. Patients in Arm 2 will continue with standard of care systemic therapy alone. The primary endpoint is OS. Secondary endpoints include event-free survival, treatment-related toxicities, and local recurrence with exploratory biomarker analyses. The study needs 346 evaluable patients combined in the 2 arms to demonstrate an improvement in OS with a hazard ratio of 0.7 to provide 80% power with a one-sided alpha of 5%. The trial utilizes a group sequential design with two interim analyses (25% and 50% of events) for futility.

RESULTS

The trial activated in January 2023.

CONCLUSION

Recruitment is ongoing.

Dry Season Transpiration and Soil Water Dynamics in the Central Amazon

With current observations and future projections of more intense and frequent droughts in the tropics, understanding the impact that extensive dry periods may have on tree and ecosystem-level transpiration and concurrent carbon uptake has become increasingly important. Here, we investigate paired soil and tree water extraction dynamics in an old-growth upland forest in central Amazonia during the 2018 dry season. Tree water use was assessed via radial patterns of sap flow in eight dominant canopy trees, each a different species with a range in diameter, height, and wood density. Paired multi-sensor soil moisture probes used to quantify volumetric water content dynamics and soil water extraction within the upper 100 cm were installed adjacent to six of those trees. To link depth-specific water extraction patterns to root distribution, fine root biomass was assessed through the soil profile to 235 cm. To scale tree water use to the plot level (stand transpiration), basal area was measured for all trees within a 5 m radius around each soil moisture probe. The sensitivity of tree transpiration to reduced precipitation varied by tree, with some increasing and some decreasing in water use during the dry period. Tree-level water use scaled with sapwood area, from 11 to 190 L per day. Stand level water use, based on multiple plots encompassing sap flow and adjacent trees, varied from ∼1.7 to 3.3 mm per day, increasing linearly with plot basal area. Soil water extraction was dependent on root biomass, which was dense at the surface (i.e., 45% in the upper 5 cm) and declined dramatically with depth. As the dry season progressed and the upper soil dried, soil water extraction shifted to deeper levels and model projections suggest that much of the water used during the month-long dry-down could be extracted from the upper 2-3 m. Results indicate variation in rates of soil water extraction across the research area and, temporally, through the soil profile. These results provide key information on whole-tree contributions to transpiration by canopy trees as water availability changes. In addition, information on simultaneous stand level dynamics of soil water extraction that can inform mechanistic models that project tropical forest response to drought.

Plant functional types broadly describe water use strategies in the Caatinga, a seasonally dry tropical forest in northeast Brazil

In seasonally dry tropical forests, plant functional type can be classified as deciduous low wood density, deciduous high wood density, or evergreen high wood density species. While deciduousness is often associated with drought-avoidance and low wood density is often associated with tissue water storage, the degree to which these functional types may correspond to diverging and unique water use strategies has not been extensively tested.We examined (a) tolerance to water stress, measured by predawn and mid-day leaf water potential; (b) water use efficiency, measured via foliar δ13C; and (c) access to soil water, measured via stem water δ18O.We found that deciduous low wood density species maintain high leaf water potential and low water use efficiency. Deciduous high wood density species have lower leaf water potential and variable water use efficiency. Both groups rely on shallow soil water. Evergreen high wood density species have low leaf water potential, higher water use efficiency, and access alternative water sources. These findings indicate that deciduous low wood density species are drought avoiders, with a specialized strategy for storing root and stem water. Deciduous high wood density species are moderately drought tolerant, and evergreen high wood density species are the most drought tolerant group.Synthesis. Our results broadly support the plant functional type framework as a way to understand water use strategies, but also highlight species-level differences.

Three-dimensional microscale hanging drop arrays with geometric control for drug screening and live tissue imaging

Existing three-dimensional (3D) culture techniques are limited by trade-offs between throughput, capacity for high-resolution imaging in living state, and geometric control. Here, we introduce a modular microscale hanging drop culture where simple design elements allow high replicates for drug screening, direct on-chip real-time or high-resolution confocal microscopy, and geometric control in 3D. Thousands of spheroids can be formed on our microchip in a single step and without any selective pressure from specific matrices. Microchip cultures from human LN229 glioblastoma and patient-derived mouse xenograft cells retained genomic alterations of originating tumors based on mate pair sequencing. We measured response to drugs over time with real-time microscopy on-chip. Last, by engineering droplets to form predetermined geometric shapes, we were able to manipulate the geometry of cultured cell masses. These outcomes can enable broad applications in advancing personalized medicine for cancer and drug discovery, tissue engineering, and stem cell research.

Evaluation of the Efficacy of Commercial Disinfectants Against Fusarium oxysporum f. sp. cubense Race 1 and Tropical Race 4 Propagules

Panama disease caused by Fusarium oxysporum f. sp. cubense has devastated banana production worldwide. This work aimed to determine effective disinfectants against two races of F. oxysporum f. sp. cubense, race 1 and tropical race 4 (TR4), for implementation with on-farm biosecurity procedures against this disease following the outbreak of TR4 in North Queensland in 2015. A total of 32 commercial disinfectants were screened and their activity was assessed after ≤30 s, 5 min, 30 min, and 24 h of contact with an F. oxysporum f. sp. cubense suspension containing 10⁵ chlamydospores/ml without and with soil added (0.05 g/ml). Of the disinfectants tested, the quaternary ammonium compounds containing ≥10% active ingredient were found to be the most effective against both F. oxysporum f. sp. cubense races. These products, when used at a 1:100 dilution, completely inhibited the survival of all F. oxysporum f. sp. cubense propagules across all the contact times regardless of the absence or presence of soil. The bioflavonoid product EvoTech 213 and bleach (10% sodium hypochlorite) used at a 1:10 dilution also eliminated all F. oxysporum f. sp. cubense propagules across all the contact times. None of the detergent-based or miscellaneous products tested were completely effective against both F. oxysporum f. sp. cubense races even used at a 1:10 dilution. Soil decreases the efficacy of disinfectants and therefore must be removed from contaminated items before treatments are applied.

Rooting strategies in a subtropical savanna: a landscape-scale three-dimensional assessment

In resource-limited savannas, the distribution and abundance of fine roots play an important role in acquiring essential resources and structuring vegetation patterns and dynamics. However, little is known regarding the three-dimensional distribution of fine roots in savanna ecosystems at the landscape scale. We quantified spatial patterns of fine root density to a depth of 1.2 m in a subtropical savanna landscape using spatially specific sampling. Kriged maps revealed that fine root density was highest at the centers of woody patches, decreased towards the canopy edges, and reached lowest values within the grassland matrix throughout the entire soil profile. Lacunarity analyses indicated that spatial heterogeneities of fine root density decreased continuously to a depth of 50 cm and then increased in deeper portions of the soil profile across this landscape. This vertical pattern might be related to inherent differences in root distribution between trees/shrubs and herbaceous species, and the presence/absence of an argillic horizon across this landscape. The greater density of fine roots beneath woody patches in both upper and lower portions of the soil profile suggests an ability to acquire disproportionately more resources than herbaceous species, which may facilitate the development and persistence of woody patches across this landscape.

Lysine bioavailability among 2 lipid-coated lysine products after exposure to silage

We conducted 2 experiments to determine lysine bioavailability from 2 lipid-coated lysine products. In an in vitro experiment we mixed each lipid-coated lysine product with either alfalfa- or corn-silage at different amounts of acidity. Scanning electron micrographs indicated that surface structure of each lipid-coated lysine particle was eroded after mixing with silage. Additionally, visual evaluation of scanning electron micrographs suggested that peripheral surface abrasion of lipid-coated lysine may be greater when lipid-coated lysine was mixed with alfalfa silage in comparison to corn silage. In a corresponding experiment, in vivo measures of lysine bioavailability to sheep from 2 lipid-coated lysine products and lysine-HCl were determined after mixing in corn silage. Plasma lysine concentrations increased linearly (P < 0.01) in response to abomasal lysine infusion indicating that our model was sensitive to increases in metabolizable lysine flow. Bioavailability of each lipid-coated lysine source and dietary lysine-HCl were calculated to be 23, 15, and 18%, respectively. Even though each dietary source of lysine increased plasma lysine, rates of increases in plasma lysine from one lipid-coated lysine source (linear; P = 0.20) and lysine-HCl (linear; P = 0.11) were not different from plasma lysine levels supported by diet alone. However, the rate of plasma lysine increase in response to lysine from the other lipid-coated lysine source was greater (P = 0.04) than plasma lysine from feed alone. Nonetheless, the rate of plasma lysine increase in response to lipid-coated lysine did not differ (P ≥ 0.70) from the rate of plasma lysine increase from lysine-HCl. Clearly, methods of manufacture, together with physical and chemical characteristics of diet, can impact amounts of metabolizable lysine provided from lipid-coated lysine products. Direct measures of lysine bioavailability from lipid-coated lysine products after mixing with diets should be based on measurements with the products treated similarly to the method of feeding.

Effect of stocking density on performance, diet selection, total-tract digestion, and nitrogen balance among heifers grazing cool-season annual forages

Grazing annual cool-season forages after oat grain harvest in South Dakota may allow an opportunity to increase efficient use of tillable land. However, data are limited regarding effects of stocking density on diet selection, nutrient digestion, performance, and N retention by cattle grazing annual cool-season forage. Heifers were blocked by initial BW (261 ± 11.7 kg) and randomly assigned to 1 of 12 paddocks (1.1 ha) to graze a mixture of grass and brassica for 48 d. Each paddock contained 3, 4, or 5 heifers to achieve 4 replicates of each stocking density treatment. Ruminally cannulated heifers were used to measure diet and nutrient intake. Effects of stocking density on diet and nutrient selection were measured after 2, 24, and 46 d of grazing, and BW was measured at the beginning, middle, and end of the experiment as the average of d 1 and 2, d 22 and 23, and d 47 and 48 BW, respectively. Measures of DMI and DM, OM, NDF, and ADF digestion were collected from d 18 to 23. Increased stocking density increased intake of brassica relative to grass on d 24 (quadratic, = 0.02), but increased stocking density decreased (linear, ≤ 0.01) intake of brassica compared with grass on d 48 (stocking density × time, < 0.01). Increased stocking density increased DM (quadratic, < 0.01), OM (quadratic, = 0.01), and NDF (quadratic, = 0.05) digestion, and stocking density tended to increase DMI (quadratic, = 0.07). Additionally, increased stocking density quadratically increased ( = 0.05) N retention but did not affect overall BW gains. Increased stocking density did, however, contribute to linearly decreased ( = 0.05) BW gains from d 1 to 22 of grazing, but BW gains during the latter half of the experiment were greater than BW gains from d 1 to 22. Ruminal concentration of acetate:propionate was least on d 24 of grazing, and ruminal nitrate concentration tended to linearly decrease ( = 0.06) with greater amounts of time on pasture. Ruminal liquid and particulate fill and amounts of VFA were less (quadratic, ≤ 0.01) with greater amounts of time on pasture. Apparently, binary mixtures of brassica and grass planted after oat grain harvest can provide an opportunity to increase efficient use of land by providing forage resources. Increased stocking density may facilitate a more rapid adaptation to and intake of brassica among cattle grazing brassica-grass-based pastures.

32nd International Austrian Winter Symposium : Zell am See, the Netherlands. 20-23 January 2016

A1 68Ga-PSMA PET/CT in staging and restaging of Prostate Cancer Patients: comparative study with 18F-Choline PET/CT

W Langsteger, A Rezaee, W Loidl, HS Geinitz, F Fitz, M Steinmair, G Broinger, L Pallwien-Prettner, M Beheshti

A2 F18 Choline PET – CT: an accurate diagnostic tool for the detection of parathyroid adenoma?

L Imamovic, M Beheshti, G Rendl, D Hackl, O Tsybrovsky, M Steinmair, K Emmanuel, F Moinfar, C Pirich, W Langsteger

A3 [18F]Fluoro-DOPA-PET/CT in the primary diagnosis of medullary thyroid carcinoma

A Bytyqi, G Karanikas, M Mayerhöfer, O Koperek, B Niederle, M Hartenbach

A4 Variations of clinical PET/MR operations: An international survey on the clinical utilization of PET/MRI

T Beyer, K Herrmann, J Czernin

A5 Standard Dixon-based attenuation correction in combined PET/MRI: Reproducibility and the possibility of Lean body mass estimation

I Rausch, P Rust, MD DiFranco, M Lassen, A Stadlbauer, ME Mayerhöfer, M Hartenbach, M Hacker, T Beyer

A6 High resolution digital FDG PET/MRI imaging for assessment of ACL graft viability

K Binzel, R Magnussen, W Wei, MU Knopp, DC Flanigan, C Kaeding, MV Knopp

A7 Using pre-existing hematotoxicity as predictor for severe side effects and number of treatment cycles of Xofigo therapy

A Leisser, M Nejabat, M Hartenbach, G Kramer, M Krainer, M Hacker, A Haug

A8 QDOSE – comprehensive software solution for internal dose assessment

Wencke Lehnert, Karl Schmidt, Sharok Kimiaei, Marcus Bronzel, Andreas Kluge

A9 Clinical impact of Time-of-Flight on next-generation digital PET imaging of Yttrium-90 radioactivity following liver radioembolization

CL Wright, K Binzel, J Zhang, Evan Wuthrick, Piotr Maniawski, MV Knopp

A10 Snakes in patients! Lessons learned from programming active contours for automated organ segmentation

M Blaickner, E Rados, A Huber, M Dulovits, H Kulkarni, S Wiessalla, C Schuchardt, RP Baum, B Knäusl, D Georg

A11 Influence of a genetic polymorphism on brain uptake of the dual ABCB1/ABCG2 substrate [11C]tariquidar

M Bauer, B Wulkersdorfer, W Wadsak, C Philippe, H Haslacher, M Zeitlinger, O Langer

A12 Outcome prediction of temporal lobe epilepsy surgery from P-glycoprotein activity. Pooled analysis of (R)-[11C]-verapamil PET data from two European centres

M Bauer, M Feldmann, R Karch, W Wadsak, M Zeitlinger, MJ Koepp, M-C Asselin, E Pataraia, O Langer

A13 In-vitro and in-vivo characterization of [18F]FE@SNAP and derivatives for the visualization of the melanin concentrating hormone receptor 1

M Zeilinger, C Philippe, M Dumanic, F Pichler, J Pilz, M Hacker, W Wadsak, M Mitterhauser

A14 Reducing time in quality control leads to higher specific radioactivity of short-lived radiotracers

L Nics, B Steiner, M Hacker, M Mitterhauser, W Wadsak

A15 In vitro 11C-erlotinib binding experiments in cancer cell lines with epidermal growth factor receptor mutations

A Traxl, Thomas Wanek, Kushtrim Kryeziu, Severin Mairinger, Johann Stanek, Walter Berger, Claudia Kuntner, Oliver Langer

A16 7-[11C]methyl-6-bromopurine, a PET tracer to measure brain Mrp1 function: radiosynthesis and first PET evaluation in mice

S Mairinger, T Wanek, A Traxl, M Krohn, J Stanek, T Filip, M Sauberer, C Kuntner, J Pahnke, O Langer

A17 18F labeled azidoglucose derivatives as “click” agents for pretargeted PET imaging

D Svatunek, C Denk, M Wilkovitsch, T Wanek, T Filip, C Kuntner-Hannes, J Fröhlich, H Mikula

A18 Bioorthogonal tools for PET imaging: development of radiolabeled 1,2,4,5-Tetrazines

C Denk, D Svatunek, T Wanek, S Mairinger, J Stanek, T Filip, J Fröhlich, H Mikula, C Kuntner-Hannes

A19 Preclinical evaluation of [18F]FE@SUPPY- a new PET-tracer for oncology

T Balber, J Singer, J Fazekas, C Rami-Mark, N Berroterán-Infante, E Jensen-Jarolim, W Wadsak, M Hacker, H Viernstein, M Mitterhauser

A20 Investigation of Small [18F]-Fluoroalkylazides for Rapid Radiolabeling and In Vivo Click Chemistry

C Denk, D Svatunek, B Sohr, H Mikula, J Fröhlich, T Wanek, C Kuntner-Hannes, T Filip

A21 Microfluidic 68Ga-radiolabeling of PSMA-HBED-CC using a flow-through reactor

S Pfaff, C Philippe, M Mitterhauser, M Hartenbach, M Hacker, W Wadsak

A22 Influence of 24-nor-ursodeoxycholic acid on hepatic disposition of [18F]ciprofloxacin measured with positron emission tomography

T Wanek, E Halilbasic, M Visentin, S Mairinger, B Stieger, C Kuntner, M Trauner, O Langer

A23 Automated 18F-flumazenil production using chemically resistant disposable cassettes

P Lam, M Aistleitner, R Eichinger, C Artner

A24 Similarities and differences in the synthesis and quality control of 177Lu-DOTA-TATE, 177Lu -HA-DOTA-TATE and 177Lu-DOTA-PSMA (PSMA-617)

H Eidherr, C Vraka, A Haug, M Mitterhauser, L Nics, M Hartenbach, M Hacker, W Wadsak

A25 68Ga- and 177Lu-labelling of PSMA-617

H Kvaternik, R Müller, D Hausberger, C Zink, RM Aigner

A26 Radiolabelling of liposomes with 67Ga and biodistribution studies after administration by an aerosol inhalation system

U Cossío, M Asensio, A Montes, S Akhtar, Y te Welscher, R van Nostrum, V Gómez-Vallejo, J Llop

A27 Fully automated quantification of DaTscan SPECT: Integration of age and gender differences

F VandeVyver, T Barclay, N Lippens, M Troch

A28 Lesion-to-background ratio in co-registered 18F-FET PET/MR imaging – is it a valuable tool to differentiate between low grade and high grade brain tumor?

L Hehenwarter, B Egger, J Holzmannhofer, M Rodrigues-Radischat, C Pirich

A29 [11C]-methionine PET in gliomas - a retrospective data analysis of 166 patients

N Pötsch, I Rausch, D Wilhelm, M Weber, J Furtner, G Karanikas, A Wöhrer, M Mitterhauser, M Hacker, T Traub-Weidinger

A30 18F-Fluorocholine versus 18F-Fluorodeoxyglucose for PET/CT imaging in patients with relapsed or progressive multiple myeloma: a pilot study

T Cassou-Mounat, S Balogova, V Nataf, M Calzada, V Huchet, K Kerrou, J-Y Devaux, M Mohty, L Garderet, J-N Talbot

A31 Prognostic benefit of additional SPECT/CT in sentinel lymph node mapping of breast cancer patients

S Stanzel, G Pregartner, T Schwarz, V Bjelic-Radisic, B Liegl-Atzwanger, R Aigner

A32 Evaluation of diagnostic value of TOF-18F-FDG PET/CT in patients with suspected pancreatic cancer

S Stanzel, F Quehenberger, RM Aigner

A33 New quantification method for diagnosis of primary hyperpatahyroidism lesions and differential diagnosis vs thyropid nodular disease in dynamic scintigraphy

A Koljević Marković, Milica Janković, V Miler Jerković, M Paskaš, G Pupić, R Džodić, D Popović

A34 A rare case of diffuse pancreatic involvement in patient with merkel cell carcinoma detected by 18F-FDG

MC Fornito, D Familiari

A35 TSH-stimulated 18F-FDG PET/CT in the diagnosis of recurrent/metastatic radioiodine-negative differentiated thyroid carcinomas in patients with various thyroglobuline levels

P Koranda, H Polzerová, I Metelková, L Henzlová, R Formánek, E Buriánková, M Kamínek

A36 Breast Dose from lactation following I131 treatment

WH Thomson, C Lewis

A37 A new concept for performing SeHCAT studies with the gamma camera

WH Thomson, J O’Brien, G James, A Notghi

A38 Whole body F-18-FDG-PET and tuberculosis: sensitivity compared to x-ray-CT

H Huber, I Stelzmüller, R Wunn, M Mandl, F Fellner, B Lamprecht, M Gabriel

A39 Emerging role 18F-FDG PET-CT in the diagnosis and follow-up of the infection in heartware ventricular assist system (HVAD)

MC Fornito, G Leonardi

A40 Validation of Poisson resampling software

WH Thomson, J O’Brien, G James

A41 Protection of PET nuclear medicine personnel: problems in satisfying dose limit requirements

J Hudzietzová, J Sabol, M Fülöp

Study protocol for an evaluation of the effectiveness of 'care bundles' as a means of improving hospital care and reducing hospital readmission for patients with chronic obstructive pulmonary disease (COPD)

BACKGROUND

Chronic Obstructive Pulmonary Disease is one of the commonest respiratory diseases in the United Kingdom, accounting for 10% of unplanned hospital admissions each year. Nearly a third of these admitted patients are re-admitted to hospital within 28 days of discharge. Whilst there is a move within the NHS to ensure that people with long-term conditions receive more co-ordinated care, there is little research evidence to support an optimum approach to this in COPD. This study aims to evaluate the effectiveness of introducing standardised packages of care i.e. care bundles, for patients with acute exacerbations of COPD as a means of improving hospital care and reducing re-admissions.

METHODS / DESIGN

This mixed-methods evaluation will use a controlled before-and-after design to examine the effect of, and costs associated with, implementing care bundles for patients admitted to hospital with an acute exacerbation of COPD, compared with usual care. It will quantitatively measure a range of patient and organisational outcomes for two groups of hospitals - those who deliver care using COPD care bundles, and those who deliver care without the use of COPD care bundles. These care bundles may be provided for patients with COPD following admission, prior to discharge or at both points in the care pathway. The primary outcome will be re-admission to hospital within 28 days of discharge, although the study will additionally investigate a number of secondary outcomes including length of stay, total bed days, in-hospital mortality, costs of care and patient / carer experience. A series of nested qualitative case studies will explore in detail the context and process of care as well as the impact of COPD bundles on staff, patients and carers.

DISCUSSION

The results of the study will provide information about the effectiveness of care bundles as a way of managing in-hospital care for patients with an acute exacerbation of COPD. Given the number of unplanned hospital admissions for this patient group and their rate of subsequent re-admission, it is hoped that this evaluation will make a timely contribution to the evidence on care provision, to the benefit of patients, clinicians, managers and policy-makers.

TRIAL REGISTRATION

International Standard Randomised Controlled Trials - ISRCTN13022442 - 11 February 2015.

Effects of high-sulphur water on hepatic gene expression of steers fed fibre-based diets

Sulphur-induced polioencephalomalacia (sPEM), a neurological disorder affecting ruminants, is frequently associated with the consumption of high-sulphur (S) water and subsequent poor performance. Currently, there is no economical method for S removal from surface water sources, and alternative water sources are typically neither readily available nor cost-effective. Determination of genes differentially expressed in response to high-S water consumption may provide a better understanding of the physiology corresponding to high dietary S and ultimately lead to the development of treatment and prevention strategies. The objective of this study was to determine changes in gene expression in the liver, an organ important for S metabolism, of fibre-fed steers consuming high-S water. For this study, liver tissues were collected on the final day of a trial from yearling steers randomly assigned to low-S water control (566 mg/kg SO4 ; n = 24), high-S water (3651 mg/kg SO4 ; n = 24) or high-S water plus clinoptilolite supplemented at either 2.5% (n = 24) or 5.0% (n = 24) of diet dry matter (DM). Microarray analyses on randomly selected healthy low-S control (n = 4) and high-S (n = 4; no clinoptilolite) steers using the Affymetrix GeneChip Bovine Genome Array revealed 488 genes upregulated (p < 0.05) and 154 genes downregulated (p < 0.05) in response to the high- vs. low-S water consumption. Real-time RT-PCR confirmed the upregulation (p < 0.10) of seven genes involved in inflammatory response and immune functions. Changes in such genes suggest that ruminant animals administered high-S water may be undergoing an inflammation or immune response, even if signs of sPEM or compromised health are not readily observed. Further study of these, and other affected genes, may deliver new insights into the physiology underlying the response to high dietary S, ultimately leading to the development of treatments for high S-affected ruminant livestock.

Influence of standing estrus before an injection of GnRH during a beef cattle fixed-time AI protocol on LH release, subsequent concentrations of progesterone, and steriodogenic enzyme expression

Beef cows that exhibit estrus before fixed-time AI have been reported to have increased pregnancy success and increased concentrations of progesterone during the subsequent estrous cycle. Therefore, these experiments were conducted to evaluate if initiation of standing estrus before an injection of GnRH during a fixed-time AI protocol affected LH pulses, subsequent concentrations of progesterone, and luteal steroidogenic enzyme expression. In Experiments 1 and 2, cows were treated with the CO-Synch protocol (100 μg GnRH day -9, 25 mg PGF(2α) day -2, and 100 μg GnRH day 0) and allotted to one of two treatments: 1) cows that initiated estrus before GnRH on day 0 (estrus; n = 5) or 2) cows that did not initiate estrus and were induced to ovulate by the GnRH on day 0 (no estrus; n = 5). In Experiment 1, blood samples were collected at 15-min intervals from 0 to 6 (bleed 1), 12 to 20 (bleed 2), 26 to 34 (bleed 3), and 40 to 48 (bleed 4) h after GnRH. Daily blood samples were collected for 17 d. Initiation of estrus before the GnRH injection had no effect on LH release or the pattern of progesterone increase; however, cows detected in estrus had overall increased (P = 0.002) concentrations of progesterone compared with cows not in estrus. In Experiment 2, estrus was detected with the HeatWatch system. Location and size of the ovulatory follicle was determined on day 0 by transrectal ultrasonography at time of injection with GnRH. Blood samples were collected on days 3, 4, 5, 7, and 9; luteal tissue was collected on day 10 (n = 4 estrus and n = 9 no estrus) from corpus luteum (CL) originating from similar-sized follicles (13.0 to 16.0 mm). Total cellular RNA was extracted, and relative mRNA levels were determined by real-time reverse transcription PCR and corrected for GAPDH. There was no effect of estrus on CL weight or concentrations of progesterone. In addition, there was no effect of estrus, follicle size, or CL weight on luteal expression of LH receptor, StAR, CYP11A1, or 3βHSD. However, there was a correlation between follicle size and CL weight (P = 0.01; R(2) = 0.43); for every increase of 1 mm in follicle size, CL weight increased by 1.5 g. In summary, estrus did not influence release of LH, CL weight, progesterone concentrations, or expression of steriodogenic enzymes. However, as follicle size increased, CL weight increased; therefore, both follicle size and CL weight were associated with progesterone concentrations.

Influence of feeding various quantities of wet and dry distillers grains to finishing steers on carcass characteristics, meat quality, retail-case life of ground beef, and fatty acid profile of longissimus muscle

Two hundred forty Angus crossbred steers were used to determine the influence of feeding various quantities of wet and dry distillers grains to finishing steers on carcass characteristics, meat quality, retail-case life of ground beef, and fatty acid profile of LM. Three replications of 5 dietary treatments were randomly applied to 15 pens in each of 2 yr. A finishing diet containing dry-rolled corn, soybean meal, and alfalfa hay was fed as the control diet. Wet distillers grains with solubles (DGS) or dry DGS was added to the finishing diets at either 20.0 or 40.0% of the dietary DM to replace all soybean meal and part of the cracked corn in treatment diets. Carcasses of steers fed DGS had greater (P < 0.05) fat thickness (1.47 vs. 1.28 cm), greater (P < 0.05) USDA yield grades (3.23 vs. 2.94), and smaller (P < 0.05) percentage of yield grades 1 and 2 (41.1 vs. 60.4%) than carcasses of steers fed the control diet. Longissimus muscle from steers fed dry DGS had greater (P < 0.05) ultimate pH values (5.52 vs. 5.49) than LM from steers fed wet DGS. Ground beef from steers fed DGS had greater (P < 0.05) concentrations of α-tocopherol (1.77 vs. 1.43 μg/g) than ground beef from steers fed the control diet. Ground beef from steers fed 40% DGS had greater (P < 0.05) thiobarbituric acid-reactive substances (2.84 vs. 2.13 mg/kg) on d 2 of retail display than ground beef from steers fed 20% DGS. Longissimus muscle of steers fed DGS had less (P < 0.05) C17:0 and more (P < 0.05) C18:0, C18:1t, C16:1c9, C18:2c9c12 (where t is trans and c is cis), and total PUFA than LM of steers fed the control diet. Feedlot steers fed DGS may need to be marketed earlier than normal to avoid excess external fat and carcasses with a greater numerical yield grade. These data suggest feeding DGS to finishing steers will have no adverse or beneficial effects on glycolytic variables (dark cutters), retail display life of ground beef, or meat tenderness. However, beef from cattle finished on diets containing DGS will likely have a greater proportion of PUFA and therefore may be more susceptible to oxidative rancidity.

Mechanisms mediating oestradiol modulation of the developing brain

The brain has been known to be a sensitive target organ for the permanent organisational effects of gonadal steroids for close to 50 years. Recent advances have revealed a variety of unexpected cellular mechanisms by which steroids impact on the synaptic profile of hypothalamic nuclei critical to the control of reproduction. This review focuses on three in particular: 1) prostaglandins in the masculinisation of the preoptic area and control of male sexual behaviour; 2) GABA in the arcuate nucleus and potential control of the anterior pituitary; and 3) non-genomic activation of phosphotydolinositol 3 (PI3) kinase and glutamate in the ventromedial nucleus, which is relevant to the control of female reproductive behaviour. The importance of cell-to-cell communication, be it between neurones or between neurones and astrocytes, is highlighted as an essential principle for expanding the impact of steroids beyond those cells that express nuclear receptors.

Uptake of zinc from zinc sulfate and zinc proteinate by ovine ruminal and omasal epithelia

Uptake and transport of Zn from (65)Zn-labeled ZnSO(4) and Zn proteinate (ZnProt) by ruminal and omasal epithelia were examined by using a parabiotic chamber system. Uptake was measured during a 4-h incubation with 10, 20, or 200 microM Zn as ZnSO(4) or ZnProt in the mucosal buffer (pH 6.0, Krebs-Ringer phosphate). Zinc uptake and transport were also evaluated after simulated ruminal digestion. Buffered ruminal fluid contained a feed substrate and 10 or 200 microM added Zn as ZnSO(4) or ZnProt. In a preliminary experiment, uptake of Zn by omasal tissue was low; thus, the remaining experiments were conducted solely with ruminal epithelium. Incubations to determine the effect of time on Zn uptake from mucosal buffer containing 20 microM added Zn as ZnSO(4) or ZnProt resulted in increased (P < 0.01) Zn uptake as incubation time increased from 30 to 240 min. Zinc uptake was also greater (P = 0.02) from mucosal buffer containing ZnProt compared with ZnSO(4). Zinc uptake from incubations containing 10 or 200 microM was affected by source x concentration (P = 0.05) and concentration x time (P < 0.01) interactions. With 10 microM Zn, uptake was not influenced by Zn source, whereas when 200 microM Zn was added, Zn uptake from ZnProt was greater than from ZnSO(4). Increasing incubation time resulted in increased Zn uptake with 200 microM Zn in the mucosal buffer; however, with 10 microM Zn, uptake did not change after 30 min. After simulated ruminal fermentation, the proportion of Zn in a soluble form was influenced by a source x concentration interaction (P = 0.03). After 18 h of incubation, the proportion of Zn that was soluble was not different between ZnProt and ZnSO(4) in buffered ruminal fluid that contained 10 microM added Zn, but was greater for ZnProt compared with ZnSO(4) with 200 microM Zn in the incubation. Zinc uptake from the aqueous fractions of simulated ruminal digestions containing 200 microM added Zn was greater (P < 0.01) than from those containing 10 microM added Zn. Zinc transport, based on detection of (65)Zn in serosal buffer, did not occur in any of the experiments. The results of the current experiments suggest that absorption of Zn into the bloodstream does not occur from the ruminant foresto-mach; however, Zn uptake occurs in ruminal tissue and is greater from ZnProt than from ZnSO(4).

Conversion of a tumor-binding peptide identified by phage display to a functional chimeric T cell antigen receptor

Adoptive transfer of ex vivo expanded tumor-specific T cells is a promising therapeutic modality for promoting or augmenting antitumor immunity. Several groups, including ours, are developing antigen receptor gene transfer strategies as a means of generating effector cells for adoptive therapy. Chimeric antigen receptors (CARs) have been described that use single-chain antibodies or cytokine ligands as tumor targeting domains. Here, we describe the capacity of a tumor-binding peptide identified by phage display combinatorial library screening to serve as a CAR targeting domain. A phage library-selected high-affinity 12-mer peptide (Bpep) specific for alpha(v) beta(6) integrin (alpha v beta6) was chosen for these studies. Primary human T cells were genetically modified to express the Bpep-CAR consisting of an alpha v beta6-specific peptide and human IgG4 hinge-Fc extracellular domain fused to the cytoplasmic tail of CD3-zeta. T cell expression of the Bpep-CAR was assessed by Western blot analysis, and trafficking of the Bpep-CAR to the cell surface was demonstrated by flow cytometry. Functionally, Bpep-CAR redirected cytotoxic T lymphocytes specifically kill integrin alpha v beta6+ ovarian tumor targets, and are activated for interferon gamma secretion. Our data suggest that large new repertoires of tumor-specific T cell antigen receptor transgenes might be available through merging combinatorial peptide libraries with CAR construct design.

Nonsteroidal anti-inflammatory drug-induced strictures of the colon: report of a case and review of the literature

The phenomenon of strictures of the colon induced by nonsteroidal anti-inflammatory drugs is a newly recognized pathologic entity that has gained little exposure in the surgical literature to date. A further case is reported and the clinical features of this entity are discussed. Most patients present with symptoms suggestive of malignancy, namely anemia, obstructive symptoms, or weight loss. Pathologic changes are characterized by diaphragm-like strictures with submucosal fibrosis. Surgical resection to exclude malignancy and treat symptoms along with cessation of the nonsteroidal anti-inflammatory drug is the treatment of choice.

The physical maps for sequencing human chromosomes 1, 6, 9, 10, 13, 20 and X

We constructed maps for eight chromosomes (1, 6, 9, 10, 13, 20, X and (previously) 22), representing one-third of the genome, by building landmark maps, isolating bacterial clones and assembling contigs. By this approach, we could establish the long-range organization of the maps early in the project, and all contig extension, gap closure and problem-solving was simplified by containment within local regions. The maps currently represent more than 94% of the euchromatic (gene-containing) regions of these chromosomes in 176 contigs, and contain 96% of the chromosome-specific markers in the human gene map. By measuring the remaining gaps, we can assess chromosome length and coverage in sequenced clones.

Effects of dietary copper source and concentration on carcass characteristics and lipid and cholesterol metabolism in growing and finishing steers

We conducted an experiment to determine the effects of dietary copper (Cu) source and level on carcass characteristics, longissimus muscle fatty acid composition, and serum and muscle cholesterol concentrations in steers. Sixty Angus and Angus x Hereford steers were stratified by weight and initial liver Cu concentration within a breed and randomly assigned to treatments. Treatments consisted of: 1) control (no supplemental Cu); 2) 20 mg Cu/kg DM from Cu sulfate (CuSO4); 3) 40 mg Cu/kg DM from CuSO4; 4) 20 mg Cu/kg DM from Cu citrate; 5) 20 mg Cu/kg DM from Cu proteinate; and 6) 20 mg Cu/kg DM from tribasic Cu chloride. A corn silage-soybean meal-based diet was fed for 56 d. Steers were then switched to a high-concentrate diet. Equal numbers (n = 5) of steers per treatment were slaughtered after receiving the finishing diets for either 101 or 121 d. Serum cholesterol was not affected by treatment during the growing phase but was decreased (P < .05) in steers supplemented with Cu by d 84 of the finishing period and remained lower (P < . 05) at subsequent sampling periods. Longissimus muscle cholesterol concentration tended to be reduced (P < .11) by Cu supplementation. Hot carcass weight and backfat were lower (P < .05) in animals receiving supplemental Cu. However, Cu-supplemented and control steers had similar marbling scores. Longissimus muscle polyunsaturated fatty acid concentrations (18:2 and 18:3) were increased (P < .07) and saturated fatty acid concentrations tended (P < . 11) to be reduced by Cu supplementation. These results indicate that as little as 20 mg of supplemental Cu/kg diet can reduce backfat and serum cholesterol and increase muscle polyunsaturated fatty acids in steers fed high-concentrate diets.

Psoriasis upregulated phorbolin-1 shares structural but not functional similarity to the mRNA-editing protein apobec-1

Earlier studies of psoriatic and normal primary keratinocytes treated with phorbol 12-myristate-1-acetate identified two low-molecular-weight proteins, termed phorbolin-1 (20 kDa; pI 6.6) and phorbolin-2 (17.6 kDa; pI 6.5). As a first step towards elucidating the role of these proteins in psoriasis, we report here the molecular cloning and chromosomal mapping of phorbolin-1 and a related cDNA that codes for a protein exhibiting a similar amino acid sequence. The phorbolins were mapped to position 22q13 immediately centromeric to the c-sis proto-oncogene. Transient expression of the phorbolin-1 cDNA in COS cells and by in vitro transcription/translation, yielded polypeptides that comigrated with phorbolins-1 and -2. Comparative sequence analysis revealed 22% overall identity and a similarity of 44% of the phorbolins to apobec-1, the catalytic subunit of the mammalian apolipoprotein B mRNA editing enzyme; however, recombinant-expressed phorbolin-1 exhibited no cytidine deaminase activity, using either a monomeric nucleoside or apolipoprotein B cRNA as substrate, and failed to bind an AU-rich RNA template. Whereas the precise function of the phorbolins remains to be elucidated, the current data suggest that it is unlikely to include a role in the post-transcriptional modification of RNA in a manner analogous to that described for apobec-1.

Complete nucleotide sequence of the 27-kilobase virulence related locus (vrl) of Dichelobacter nodosus: evidence for extrachromosomal origin

The vrl locus is preferentially associated with virulent isolates of the ovine footrot pathogen, Dichelobacter nodosus. The complete nucleotide sequence of this 27.1-kb region has now been determined. The data reveal that the locus has a G+C content much higher than the rest of the D. nodosus chromosome and contains 22 open reading frames (ORFs) encoding products including a putative adenine-specific methylase, two potential DEAH ATP-dependent helicases, and two products with sequence similarity to a bacteriophage resistance system. These ORFs are all in the same orientation, and most are either overlapping or separated by only a few nucleotides, suggesting that they comprise an operon and are translationally coupled. Expression vector studies have led to the identification of proteins that correspond to many of these ORFs. These data, in combination with evidence of insertion of vrl into the 3' end of an ssrA gene, are consistent with the hypothesis that the vrl locus was derived from the insertion of a bacteriophage or plasmid into the D. nodosus genome.

Sclerosing sweat-duct carcinoma (malignant syringoma) of the upper eyelid: a patient report with immunohistochemical and ultrastructural analysis

Sclerosing sweat-duct carcinoma or malignant syringoma is a rare eyelid tumor. The authors report the first patient with sclerosing sweat-duct carcinoma involving the upper eyelid and present its immunohistochemical and ultrastructural features. The clinical features and the histopathologic and ultrastructural findings that distinguish this tumor from its benign counterparts are discussed. Sclerosing sweat-duct carcinomas are slow growing but locally invasive neoplasms that have a propensity to recur. Wide and deep surgical excision with frozen section evaluation of margins is recommended.

Histology of the stomach and duodenum in Crohn's disease

Crohn's disease (CD) not uncommonly affects the stomach and duodenum, but its histologic appearance is not well described beyond the identification of granulomas. We retrospectively identified 209 upper gastrointestinal biopsy samples from 80 sets of biopsies from 49 patients with CD. Age- and sex-matched control biopsies were selected from recent cases of Helicobacter pylori gastritis (73 biopsy samples from 34 patients), from patients with a known history of nonsteroidal antiinflammatory drug use (18 biopsy samples from 12 patients), and from three patients with ulcerative colitis. Architectural and inflammatory changes were evaluated and compared. Over three fourths of the patients with CD had abnormal biopsy results. Fifty-six percent of patients with CD had acute inflammation, but only 10% of the patients were infected with H pylori. Focal acute inflammation was a characteristic of H pylori-negative CD (stomach, 31%; duodenum, 40%), which was much less common in the non-CD group (stomach, 2%; duodenum, 8%). Surface intraepithelial neutrophils of the duodenum were more common in H pylori-negative patients with CD (25%) than in those who did not have CD (4%), and deep acute inflammation of the duodenum was more likely in H pylori-negative patients with CD (19% vs. 0%). Granulomas were found in only 9% of the CD group. Focal acute inflammation of the gastroduodenum, especially in a background of noninflamed mucosa, is strong evidence for CD in the appropriate clinical context, but the stomach and duodenum must be properly sampled and carefully examined for any evidence of H pylori.

A retrospective molecular analysis of gentamicin resistance in Staphylococcus aureus strains from UK hospitals

The composite transposon Tn4001 and a related chromosomal Tn4001-like element, encode resistance to the aminoglycosides gentamicin, tobramycin and kanamycin (GmTmKmr) in Australian strains of Staphylococcus aureus. Southern hybridisation analysis of GmTmKmr S. aureus strains isolated from various hospitals in the UK between 1975 and 1985 indicated that they predominantly encoded chromosomal copies of Tn4001 or a Tn4001-like element. However, a strain isolated in 1985 was found to carry Tn4001 on a plasmid related to pSK1, the prototypical multiresistance plasmid commonly detected in S. aureus strains from Australian hospitals.

Development of a candidate HLA A*0201 restricted peptide-based vaccine against human cytomegalovirus infection

The development of a protective cellular immune response against human cytomegalovirus (HCMV) is the most important determinant of recovery from HCMV infection after allogeneic bone marrow transplantation (BMT). The ultimate aim of our study is to develop an antigen-specific and peptide-based vaccine strategy against HCMV in the setting of BMT. Toward this end we have studied the cellular immune response against the immunodominant matrix protein pp65 of HCMV. Using an HLA A*0201-restricted T-cell clone reactive against pp65 from peripheral blood from a seropositive individual, we have mapped the position of the cytolytic T lymphocyte (CTL) epitope from HCMV pp65 to an 84-amino acid segment. Of the four peptides which best fit the HLA A*0201 motif in that region, one nonamer sensitized an autologous Epstein-Barr virus immortalized lymphocyte cell line for lysis. In vitro immunization of PBMC from HLA A*0201 and HCMV seropositive volunteers using the defined nonamer peptide stimulated significant recognition of HCMV infected or peptide-sensitized fibroblasts. Similarly, HLA A*0201 transgenic mice immunized with the nonamer peptide developed CTL that recognize both the immunizing peptide and endogenously processed pp65 in an HLA A*0201 restricted manner. Lipid modification of the amino terminus of the nonamer peptide resulted in its ability to stimulate immune responses without the use of adjuvant. This demonstration of a vaccine function of the nonamer peptide without adjuvant suggests its potential for use in an immunization trial of BMT donors to induce protective CTLs in patients undergoing allogeneic BMT.

Characterization of a Pasteurella multocida plasmid and its use to express recombinant proteins in P. multocida

The complete nucleotide sequence of a naturally occurring 5.36-kb streptomycin and sulphonamide resistance plasmid, designated pIG1, isolated from type D Pasteurella multocida was determined. A 1.6-kb noncoding region and a 1.4-kb region encoding three putative proteins were shown by sequence homologies and functional characterizations to be involved in the replication and mobilization of pIG1, respectively. The remaining sequence carried an unusual arrangement of streptomycin- and sulphonamide-resistant genes when compared to various other plasmids. It appears that the antibiotic resistance region of pIG1 may have evolved by recombination between three different short direct repeat DNA sequences. A 4.5-kb recombinant plasmid was constructed by replacing the antibiotic resistance genes of pIG1 with a kanamycin resistance gene and seven unique restriction sites. The resulting plasmid, designated pIG112, stably replicates in P. multocida, Pasteurella haemolytica, Actinobacillus pleuropneumoniae, and Escherichia coli and can be introduced into these organisms by either transformation or conjugation. This vector exists at approximately 70 copies per cell in P. multocida and approximately 20 copies per cell in E. coli. To demonstrate plasmid-borne gene expression in P. multocida, the P. multocida dermonecrotic toxin gene, toxA, and a genetically modified form of this gene were cloned into pIG112 and expressed in high amounts in a nontoxigenic P. multocida strain. Cell culture assays demonstrated that nontoxigenic P. multocida expressing toxA was cytopathic, whereas a strain expressing the modified toxA derivative was not.

Protamines of reptiles

We have characterized for the first time the complete primary structure of the main protamine components of the sperm from four reptiles: Chrysemys picta (turtle), Elaphe obsoleta (snake), Anolis carolinensis (lizard), and Alligator mississipiensis (crocodilian). These species were chosen to represent one of each of the main phylogenetic branches of this taxonomic group. Comparison of these protamine sequences with those already available from other vertebrate groups allows us to define properly the chemical consensus composition of protamines and provides a unique insight into their molecular evolution and classification.

Antitumor and chemopreventive effects of a clomiphene analog, MDL 103,323, in mammary carcinoma

MDL 103,323, an enclomiphene analog, was tested for binding to the estrogen receptor, inhibition of human tumor xenografts and prevention of carcinogen-induced mammary tumors. MDL 103,323 had 5-6 fold greater affinity for the human estrogen receptor than did either tamoxifen or enclomiphene. Consistent with enhanced binding affinity, MDL 103,323 was more potent against MCF-7 cell proliferation and MCF-7 xenografts in nude mice were inhibited almost completely by MDL 103,323 doses > or = 0.02 mg/mouse/day (ED50 ł 0.01 mg/mouse/day). N-methylnitrosourea induced rat mammary carcinomas were inhibited by > or = 50% at 0.003 mg/kg daily and by 90% at 0.1 mg/kg/day. The antitumor potency and efficacy of MDL 103,323 are striking and further evaluation of the compound for potential clinical utility is warranted.

Adenoid cystic carcinoma of the left main bronchus mimicking MacLeod's syndrome

A 15 year old girl who was labelled as having MacLeod's syndrome on the basis of a chest radiograph was subsequently, at the age of 23 years, found to have an adenoid cystic carcinoma obstructing the left main bronchus. This case emphasises the need to exclude a central lesion in cases of unilateral hyperlucent lung.

Delineation of the virulence-related locus (vrl) of Dichelobacter nodosus

Dichelobacter nodosus is the primary pathogen implicated in ovine footrot. In this paper we have delineated a 27 kb locus, termed the virulence-related locus (vrl), that was essentially specific for virulent D. nodosus isolates. The precise ends of this locus were mapped and the sequences of the junction regions from the virulent strain A198 were compared to corresponding sequences from the benign isolate C305. The left end of the vrl locus was located in a sequence similar to that of the small stable 10Sa RNA molecule of Escherichia coli, next to a phage-attachment-site-like sequence, which indicated that the vrl locus might have arisen by the integration of a phage. However, no attachment-like sequence could be found at the right end of the vrl locus. In the chromosome of the benign strain the sequences bordering vrl were not contiguous but were separated by about 3 kb. It was concluded that the divergence of the benign and virulent strains at this locus was a multi-step process. Several potential ORFs were identified at the junction regions but only one ORF, encoding a 126 kDa protein, was expressed in a T7 expression system in E. coli.

Enzyme-activated inhibitors of steroidal hydroxylases

Cytochrome P450 monooxygenases (CYP450) of the steroid biosynthetic pathways are highly substrate specific in comparison to the variable specificities of hepatic CYP450 enzymes. Both groups of enzymes catalyze the reductive cleavage of molecular oxygen with transfer of oxygen to the substrate to form hydroxylated derivatives. Those steroids formed in endocrine tissues represent highly specific endocrine/autocrine hormones with enhanced biological potency, while hepatic hydroxylation of steroids reduces their endocrine bioactivities and enhances urinary elimination. Changes of the hormonal milieu of endocrine and peripheral tissues are associated with the development of hyperplastic and/or malignant conditions. Hormone deprivation induces regression of endocrine dependent growth via apoptosis and may also alter growth of hormone insensitive cells by the induction of negative growth factors. Biosynthetic CYP450 enzymes of those steroids that mediate specific disease processes are potential therapeutic targets for selective intervention. This objective can be accomplished by the design of specific pseudo-substrate analogs that will be activated during enzyme-directed catalysis to produce a reactive functional group in the enzyme's active site that will either tightly or irreversibly bind and inactivate the host enzyme. The CYP450 enzymes that hydroxylate the C19 carbon of androgens (aromatase) and the C18 carbon of corticosterone (aldosterone synthase) were selected as target enzymes because they are terminal enzymes of biosynthetic pathways which hydroxylate specific angular methyl groups. Hypersecretion of their respective hormonal products, estrogens and aldosterone, are associated with specific disease conditions. Substrate analogs containing ethynyl, vinyl, or nitrile groups attached to the C19 or C18 methyl groups were enzyme-activated inhibitors. The ethynyl analogs, 19-acetylenic androstenedione (Plomestane) and 18-acetylenic deoxycorticosterone, had nanomolar inhibitory constants (Ki values) and were irreversible inactivators of their target enzymes in animal models.

Genetic organization of the duplicated vap region of the Dichelobacter nodosus genome

The recombinant plasmid pJIR318 contains a fragment of the Dichelobacter nodosus genome which is associated with virulence. Sequence analysis of the pJIR318 insert has shown that it contains four vap (virulence-associated protein) genes which are homologous to open reading frames found on the Escherichia coli F plasmid and the Neisseria gonorrhoeae cryptic plasmid (M. E. Katz, R. A. Strugnell, and J. I. Rood, Infect. and Immun. 60:4586-4592, 1992). The plasmid pJIR318 hybridizes to three regions of the D. nodosus genome, each of which has now been isolated. Regions 1 and 3 were found to be adjacent in the genome of D. nodosus A198, and the order of the vap genes in vap regions 1 and 2 were shown to be identical. Partial sequence analysis and Southern blot analysis of the vap regions showed that the three regions probably arose by a duplication event(s) followed by insertions and/or deletions. A recombinant plasmid, pJIR749, was isolated from a library of a benign D. nodosus strain, 305. This plasmid contained sequences from both ends of vap region 2. Analysis of pJIR749 showed that the sequences on either side of vap region 2 were separated by 324 bp in the genome of benign strain 305 and that the orientations of the sequences were different. It is clear that a simple insertion or deletion event did not generate the benign and virulent strains studied. A model which describes the evolution of the duplicated vap regions in D. nodosus A198 is presented.

Effect of acadesine, a new metabolic agent, on exercise-induced myocardial ischemia in chronic stable angina

Acadesine, the first of a class of adenosine-regulating agents, has been shown to possess antiischemic properties in animal models. The aim of the study was to assess the effect of acadesine on exercise-induced myocardial ischemia in patients with chronic stable angina pectoris. Twelve patients with stable angina entered a five-way, randomized double-blind study comparing the effects of four doses of acadesine with placebo on time to 1 mm ST-segment depression and other parameters of exercise tolerance. At each study period patients underwent baseline exercise testing, followed by drug or placebo infusion after a 60 minute rest period. The exercise test was repeated after 30 minutes infusion, which continued throughout recovery. Time to angina, time to 1 mm ST depression, and total exercise time during the placebo infusion were 301.1 +/- 45.3, 314.8 +/- 50.9, and 399.4 +/- 47.6 seconds. The placebo-adjusted percentage change in time to 1-mm ST segment with acadesine 6, 12, 24, and 48 mg/kg was -0.1 +/- 6.2%, 11.1 +/- 13.8%, 12.9 +/- 8.6%, and -3.2 +/- 6.8%, respectively (p = NS vs. baseline). Time to angina, total exercise time, and recovery time of the ST segment were not consistently altered by acadesine. The lack of effect across all acadesine doses is consistent with animal data from ischemia-reperfusion injury studies, where a clear dose dependency was present with a loss of effect at higher doses. Alternatively, the extent of ischemia induced by treadmill exercise may have been insufficient for the antiischemic activity of acadesine to be evident.

Biological characterization of A-ring steroids

Hydroxylated 2,19-methylene-bridged androstenediones were designed as potential mimics of enzyme oxidized intermediates of androstenedione. These compounds exhibited competitive inhibition with low micromolar affinities for aromatase. These inhibitory constants (Ki values) were 10 times greater than the 2,19-methylene-bridged androstenedione constant (Ki = 35-70 nM). However, expansion of the 2,19-carbon bridge to ethylene increased aromatase affinity by 10-fold (Ki = 2 nM). Substitution of a methylene group with oxygen and sulfur in this expanded bridge resulted in Ki values of 7 and 20 nM, respectively. When the substituent was an NH group, the apparent inhibitory kinetics changed from competitive to uncompetitive. All of these analogs exhibited time-dependent inhibition of aromatase activity following preincubation of the inhibitor with human placental microsomes prior to measuring residual enzyme activity. Part of this inhibition was NADPH cofactor-dependent for the 2,19-methyleneoxy- but not for the 2,19-ethylene-bridged androstenedione. The time-dependent inhibition for these four analogs was very rapid since they exhibited tau 50 values, the t1/2 for enzyme inhibition at infinite inhibitor concentration, of 1 to 3 min. These A-ring-bridged androstenedione analogs represent a novel series of potent steroidal aromatase inhibitors. The restrained A-ring bridge containing CH2, O, S, or NH could effectively coordinate with the heme of the P450 aromatase to allow the tight-binding affinities reflected by their nanomolar Ki values.

A-ring bridged steroids as potent inhibitors of aromatase

The design and syntheses of androstenedione derivatives with bridges spanning the 2,19-, 3,19-, 4,19- and 6, 19-positions are described. 2,19-Bridged compounds bearing hydroxyl groups on the two-carbon bridge (3a and 3b) were designed as stable carbon analogs of potential lactol intermediates in the enzymatic conversion of androgens to estrogens. Compounds 3a and 3b are competitive inhibitors of aromatase. Pyran 25 is a potent, time-dependent inhibitor of aromatase with partial NADPH dependence. These data suggest a mechanism of inhibition for 25 which involves both tight-binding competitive and mechanism-based components, with the former predominating. The sulfur, amino, and all carbon analogs of pyran 25 were prepared. Thiopyran 36, piperidine 42 and the all-carbon analog 47 are also time-dependent inhibitors of aromatase. Compound 47 is the most potent inhibitor and its time-dependent inhibition is not NADPH dependent. The kinetics of piperidine 42 suggest uncompetitive inhibition.

Metabolism of 11-deoxycorticosterone by hamster adrenal mitochondria

Metabolism of 11-deoxycorticosterone (DOC) by hamster adrenal mitochondria gives 19-hydroxy-DOC and corticosterone (via 11-hydroxylation) in approximately equal yields. The ratio of 19- to 11-hydroxylation was invariant with changes in concentration of substrate or a competitive inhibitor. It is most likely, therefore, that a single 11,19-hydroxylase catalyzes both oxidations. Both primary products are further oxidized to the corresponding carbonyl analogs, 19-oxo-DOC and 11-dehydrocorticosterone, at rates that are approx. 20% of their rates of formation. The oxidation of 11-dehydrocorticosterone is catalyzed by a dehydrogenase utilizing either NAD or NADP while the oxidation of 19-hydroxy-DOC is catalyzed by an oxidase requiring NADPH. The 11-dehydrocorticosterone is stable in this enzyme preparation while 19-oxo-DOC is metabolized to two additional products, which are tentatively identified as 19-oic-DOC and 19-norcorticosterone. 19-nor-DOC was found to be hydroxylated at a rate that is 20% faster than the rate for DOC under the same conditions. It is therefore possible that 19-norcorticosterone can arise from 19-oic-DOC via decarboxylation to 19-nor-DOC and subsequent 11-hydroxylation, but the kinetics of its formation suggest that it may actually be formed directly from 19-oxo-DOC without free intermediates. 4-Androstene-3,17-dione and 17-hydroxy-DOC were also substrates for this 11,19-hydroxylase, but 18-hydroxy-DOC was not. Maintenance of hamsters on a low sodium diet had no effect on the metabolism of DOC by the isolated adrenal mitochondria.

Regioselectivity of metabolic activation of acetylenic steroids by hepatic cytochrome P450 isozymes

Liver cytochrome P450 monooxygenases (P450), a group of isozymes that catalyze the reductive cleavage of molecular oxygen, dominate hepatic metabolism of xenobiotic lipophilic substances. These P450 enzymes exhibit broad and overlapping substrate specificities, in contrast to the P450 isozymes of the steroid biosynthetic pathways, which are highly substrate specific. Hepatic heme pigments, N-alkylated porphyrins, accumulate following the self-catalyzed destruction of P450 by the metabolic activation of 17 alpha-ethynyl steroids. Acetylenic substituted steroidal aromatase inactivators, norethisterone (NET), and 10-(2-propynyl)estr-4-ene-3,17-dione (MDL 18,962) were administered to rats to determine if the acetylenic substituent was activated by hepatic P450 mixed-function oxidases. This metabolism could result in the formation of a reactive species that would alkylate a pyrrole nitrogen atom of heme. Male Sprague-Dawley rats were treated with 0, 10, 30, or 100 mg/kg NET or MDL 18,962 intraperitoneally. Four hours later, these animals received 40 mg/kg sodium pentobarbital and their sleeping times were recorded. On arousal, the rats were killed and their livers were taken for determination of P450 content and formation of N-alkylated porphyrins (green pigments). Norethisterone inhibited hepatic P450 isozymes, resulting in a dose-related increased sleeping time (89.2 +/- 3.5 to 156.3 +/- 7.6 minutes) and decreased P450 levels (maximum 25% decrease at 100 mg/kg), and the amount of green pigments increased with doses of 10 to 100 mg/kg. In contrast, MDL 18,962 treatment did not increase sleeping time and caused only a 15% decrease in hepatic P450 content at 100 mg/kg, with no detectable green pigments.(ABSTRACT TRUNCATED AT 250 WORDS)

Enzyme inactivation by potential metabolites of an aromatase-activated inhibitor (MDL 18,962)

MDL 18,962, 19-acetylenic androstenedione, is an enzyme-activated inhibitor of estrogen biosynthesis which is in Phase I clinical evaluations as a potential therapeutic agent for estrogen-dependent cancers. 19-Acetylenic analogs corresponding to the major metabolites of androstenedione were synthesized as potential metabolites of MDL 18,962. These compounds were 19-acetylenic testosterone, the product of 17 beta-hydroxy steroid oxidoreductase, 6 beta-hydroxy- and 6-oxo-19-acetylenic androstenedione, products of P450 steroid 6 beta-hydroxylase and alcohol dehydrogenase, respectively. All of these analogs showed time-dependent inactivation of human placental aromatase activity. The time-dependent Ki and t1/2 at infinite inhibitor concentration (tau 50) were 4.3 nM, 12.0 min for MDL 18,962; 28 nM, 7.8 min for 17-hydroxy analog; 13 nM, 37 min for 6 beta-hydroxy analog; and 167 nM, 6.1 min for the 6-oxo analog. The 19-acetylenic testosterone, a confirmed metabolite from primate studies, was 25% as efficient as MDL 18,962 for aromatase inactivation, while 6 beta-hydroxy- and 6-oxo analogs were 11% and 5%, respectively as efficient as their parent compound. These data indicate that first-pass metabolism of MDL 18,962 does not cause an obligatory loss of time-dependent inhibition of human aromatase activity.

Human trophoblast xenografts in athymic mice: a model for peripheral aromatization

A novel procedure was developed for evaluating aromatase inhibitors using human enzyme in a rodent model. Human choriocarcinoma trophoblast (JAr line) cells injected subcutaneously into athymic nude mice develop into tumor xenografts in 7-14 days which represent sites for peripheral aromatization of androgens. The rapid growth of these trophoblast tumors is estrogen independent. The tumors provide a source of nonovarian human tissue which has relatively high levels of enzyme activity (248 +/- 12 pmol estrogen/g/h) for biochemical determination of in vivo aromatase inhibition. These are major advantages for pharmacological evaluations in comparison to the slow tumor growth response of most carcinogen-induced rodent mammary cancers, which are usually devoid of aromatase activity. In addition, the hormonal dependent components of rodent mammary tumors require several weeks to regress as a result of the indirect effects of estrogen deprivation on tumor growth via inhibition of prolactin dependency, a minor component relative to the role estrogen occupies in hormonally-dependent breast cancer in humans. This model of peripheral aromatization was utilized to evaluate in vivo pharmacological parameters of MDL 18,962 (10-(2-propynyl)estr-4-ene-3,17-dione) such as bioavailability of several formulations, time course and dose responses following different routes of drug administration, pharmacokinetics and tissue distribution of [14C]MDL 18,962. Tumor aromatase activities of trophoblast xenografts were significantly (P less than or equal to 0.05) inhibited when MDL 18,962 was administered intravenously, orally, subcutaneously, or via subcutaneous silastic implants. The ED50 of MDL 18,962 for tumor aromatase inhibition at 6 h after a single treatment was 1.4 mg/kg, s.c. and 3.0 mg/kg, orally. MDL 18,962 blocked aromatase activity more effectively in human trophoblast than in mouse ovarian tissue. Human trophoblast aromatase activity was inhibited by 70% following a single oral dose of 100 mg/kg of MDL 18,962, while the host's ovarian aromatase activity exhibited only marginal inhibition. In vitro, the addition of 10 microM MDL 18,962 to trophoblast tumor cytosol or mouse ovarian cytosol resulted in 99.6 and 91.4% inhibition of aromatase activity, respectively. Tissue distribution of [14C]MDL 18,962 was predominantly associated with endocrine tissues with aromatase activity and organ systems involved in steroid metabolism and excretion. These in vivo data show that MDL 18,962 an enzyme-activated aromatase inhibitor, causes prolonged aromatase inhibition in the absence of saturating levels of inhibitor.

Inhibition of human monocyte antigen presentation, but not HLA-DR expression, by cyclosporine

The effects of cyclosporine (CsA) on antigen-dependent human T cell proliferation have been studied using tetanus toxoid as the antigen. CsA significantly inhibited antigen-dependent T cell proliferation at concentrations as low as 0.1 microgram/ml. In dissecting this system we found that preexposure of separated monocytes to CsA during the period of antigen processing led to a marked inhibition of proliferation of T cells added subsequently to the monocytes. We investigated whether this suppressive effect on monocyte antigen presentation was related to monocyte HLA-DR expression, interleukin 1 (IL-1) production, or prostaglandin (PG) secretion. None of these functions seemed to be affected by CsA. In particular, human monocyte HLA-DR expression was not inhibited by CsA, even at concentration of 10 micrograms/ml. The addition of exogenous IL-1 or indomethacin did not reverse the inhibitory effects of CsA. These experiments demonstrate that CsA inhibits antigen-dependent human T cell proliferation, at least in part by acting directly on human monocytes to inhibit antigen presentation. The mechanism of action seems to be independent of IL-1 production, PG secretion, and HLA-DR expression.

Rising malpractice premiums and obstetric practice patterns. The impact on family physicians in Washington State

All 853 active members of the Washington Academy of Family Practice were surveyed in the summer of 1985 to determine the impact of rising malpractice premiums on patterns of obstetric practice. Of the 685 physicians who responded, 61% are currently practicing obstetrics. The median number of deliveries per year was 29, with a range of 1 to 130 deliveries per physician. Younger physicians, rural physicians and those in group practice were more likely to practice obstetrics than older, urban physicians in solo practice. Of the 266 respondents not currently practicing obstetrics, 77% had discontinued obstetric practice within the past five years-half because of issues related to professional liability. Of those practicing obstetrics, 50% stated that they would cease obstetric practice if malpractice premiums rose to $12,000.

Synergy between interleukin-2 and a second factor in the long-term growth of human T cells

It has recently been shown that factors in addition to interleukin-2 (IL-2) are required for the proliferation or differentiation of at least some murine T-cell lines. We have previously shown that conditioned medium from human mononuclear cells stimulated with phorbol ester and staphylococcal enterotoxin A is superior to commercial sources of IL-2 for the long-term growth of human T cells. We have identified in these supernatants a non-IL-2 factor (synergistic factor, SF) which synergizes with JURKAT IL-2 in the long-term growth of human T cells. [3H]TdR incorporation by IL-2-dependent human T cells after growth in IL-2 or SF alone for 14 days was slight, but significant. By contrast, growth in a combination of SF and IL-2 for 14 days stimulated [3H]TdR incorporation 10-20-fold higher, generally equal to the high incorporation measured when cells were grown in the presence of the conditioned medium from which SF was obtained. In a standard 2-day IL-2 assay, there was no correlation between activity and long-term growth-promoting ability. These results suggest that the 14-day assay better discerns the growth-promoting activity of various factors or combinations of factors. The mechanism of this interaction between SF and IL-2 remains to be elucidated. It is clear, however, that T-cell growth factor activity, when assessed by the long-term growth of human T cells, is not due to interleukin-2 alone.