bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface tension and contact angle of herbicide solutions affected by surfactants
Authors: Singh Megh , Orsenigo J. R. , Shah D. O.
Published: July 2007

Contact angle and surface tension were measured for distilled and hard water solutions of adjuvants, Ortho X‐77, Span‐20, Sterox‐NJ. Surfactant‐WK, Triton B‐1956, Triton X‐114, Tween‐20, and Sun Oil 11E. The same parameters were measured for suspensions of atrazine [2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine] and ametryne [2‐(ethylamino)‐4‐(isopropylamino)‐6‐(methylthio)‐s‐triazine] with and without each adjuvant. All adjuvants reduced surface tension and contact angle of distilled water; Surfactant‐WK was most effective and Tween‐20 was least effective. Increasing concentration of surfactants from 0 to 0.1% (v/v) gave progressive reduction in surface tension and contact angle while higher concentrations, 0.1 to 2.0% (v/v), had no further effect. Surfactant‐WK at 0.1% (v/v) in distilled water reduced the surfact tension from 72.8 dynes/cm to 27 dynes/cm and contact angle from 110° to 41°. An additional increase in Surfactant‐WK concentration from 0.1% (v/v) to 2% (v/v) did not further reduce surface tension and contact angle. Sun Oil 11E was identical in behavior except that it was less effective than the surfactants. Water hardness up to 1,000 ppm as Ca ions did not affect surface tension and contact angle in surfactant solutions. An aqueous solution of atrazine had a higher surface tension and contact angle than ametryne in the absence of surfactants. However, these differences were not observed when surfactants were added to either herbicide.
The storage of cottonseed. IX. Behavior of cottonseed during storage under mill conditions
Authors: Jensen Edith A. , Lambou M. G. , Andrews F. R. , Mayne R. Y. , Karon M. L. , Curet M. E. , Wilcox F. B. , Altschul A. M. , Newby Wales , Bollens Walter F.
Published: July 2007

The production of heat and the rate of formation of free fatty acids in 20‐ to 40‐ton lots of cottonseed have been found to be dependent on the initial moisture and free fatty acids contents of the seed. Even though sustained aeration controlled the temperature of the seed and reduced the moisture content appreciably, the rate of formation of free fatty acids was rapid in all the tests except those involving seed of initially low or medium moisture and low free fatty acids contents. Losses in oil content proportional to the storage interval occurred.
Cottonseed and peanut meal glues: Permanence of plywood glue joints as determined by interior and exterior accelerated cyclic service tests
Authors: Hogan Joseph T. , Arthur {jrJr} Jett C.
Published: July 2007

It has been shown that of the three protein glues tested, commercial casein glue is most resistant to both interior and exterior accelerated service tests and that cottonseed meal glue is superior to peanut meal glue and compares favorably with commercial casein glue on an interior test basis for five cycles, the strength of the casein bond changing from 384 to 283 Ibs./sq. in. and of the cottonseed meal bond changing from 375 to 264 Ibs./sq. in. Cottonseed meal glue can probably be used for bonding plywood designed primarily for interior uses, for regions of comparatively low relative humidity, and for bonding plywood which may be used in building forms which may be disearded after several times of use.
Pattern of information technology use: The impact on buyer–suppler coordination and performance
Authors: Sanders Nada R.
Published: July 2007

The use of information technologies between supply chain organizations has been shown to promote organizational coordination and have a positive impact on performance. Drawing from organizational theories of learning, we build on this research by proposing a model that relates the pattern of supplier use of IT to specific types of supply chain coordination activities and a comprehensive set of organizational benefits. Specifically, we evaluate how two patterns of IT use by suppliers (exploitation and exploration) relate to two specific types of coordination activities with their buyers (operational and strategic coordination), which in turn are posited to promote specific organizational benefits. Using data from 241 first‐tier OEM suppliers in the computer industry, our findings show that each pattern of IT use directly promotes a specific type of coordination activity. Although both types of coordination activities are needed to achieve both strategic and operational benefits, we find each coordination activity to be uniquely promoted by a specific pattern of IT use. IT use for exploitation is found to be an antecedent to operational coordination; IT use for exploration is found to be an antecedent to strategic coordination. No crossover between pattern of use and coordination activities is found. Our findings show that to achieve a complete set of benefits, suppliers must ultimately use IT for both exploration and exploitation. These findings provide a deeper understanding of the mechanism of how the pattern of IT use can result in a comprehensive set of organizational benefits for supplier firms.
One‐dimensional variational retrieval of aerosol extinction coefficient from synthetic LIDAR and radiometric measurements
Authors: Huneeus N. , Boucher O.
Published: July 2007

The Cloud and Aerosol Lidar with Orthogonal Polarization (CALIOP) [onboard the Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) platform] and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument (onboard the AQUA platform) will provide simultaneous measurements as part of the “AQUA‐train,” thus offering a unique opportunity to improve our knowledge on aerosol properties and their spatial distribution. Here we investigate to which extent both the vertical distribution of the aerosol extinction coefficient and the aerosol bimodal size distribution can be retrieved from a synergetic use of the vertically‐resolved lidar signal and the spectral radiance measurements. To this effect, a variational retrieval scheme based on a simplified radiative transfer model was developed. The extinction‐coefficient profile for fine and coarse‐mode aerosols was retrieved from synthetic observations of the profile of the attenuated backscatter lidar signal at two wavelengths and radiances at six wavelengths. Our method aims at minimizing a cost function which measures the departure of the solution to the observations. The adjoint method was applied to find the gradient of the cost function with respect to the input parameters. The retrieval scheme was tested under a realistic noise level and different microphysical perturbations. The retrieval of extinction‐coefficient profiles, for fine and coarse particles, is successful if there is a predominance of fine particles. If coarse particles dominate over fine ones, the scheme retrieves the profile of the total extinction coefficient with a higher confidence than that of the fine mode. When perturbations on the aerosol microphysical properties are introduced, thus simulating a more challenging case with incomplete information of the aerosol model present in the atmosphere, the scheme shows a very good performance in terms of total extinction‐coefficient retrieval but less success for individual modes. It retrieves the modal radii for both modes simultaneously but can not retrieve at the same time the refractive index and true‐mode radii for both modes. Results also reveal that there is some prospect for improvement in the quality of the retrieval by either increasing the size of the predefined set of aerosol models or by including other sources of independent information such as Polarization and Directionality of Earth Reflectances (POLDER)‐like measurements.
O(1S), OH, and O2(b) airglow layer perturbations due to AGWs and their implied effects on the atmosphere
Authors: Vargas Fabio , Swenson Gary , Liu Alan , Gobbi Delano
Published: July 2007

The O(1S) (green line) night airglow emission in response to atmospheric gravity wave (AGW) perturbations was simulated with a linear, one‐dimensional model. The results were combined with previously modeled O2(b, 0–1) atmospheric band and OH Meinel band emission response (Liu and Swenson, 2003) to derive amplitude and phase relations among multiple airglow layers in response to gravity waves with various intrinsic parameters and damping rates (β). The simulations show that the vertical profile of the standard deviation of the perturbed green line volume emission rate (VER) has a centroid altitude that is 3 km lower and a full‐width‐half‐maximum 2.1 km smaller than the unperturbed VER profile, similar to findings for the OH and O2(b) band layers. Relative phase differences and amplitudes of vertically propagating waves can be deduced from zenith observations of the layers. Airglow weighted responses to waves are related through a cancellation factor (CF) for both layer intensity and temperature. The vertical wavelength can be deduced from relative phase information of three airglow layers separated in altitude. The vertical flux of horizontal momentum associated with gravity waves is deduced from intrinsic wave parameters. Wave damping versus altitude is used to deduce the flux divergence and local accelerations resulting from dissipative waves. The simulations are useful in calculating wave information and wave effects on the atmosphere from multiwavelength, zenith airglow observations.
Middle atmospheric O3, CO, N2O, HNO3, and temperature profiles during the warm Arctic winter 2001–2002
Authors: Muscari Giovanni , di Sarra Alcide G. , de Zafra Robert L. , Lucci Francesco , Baordo Fabrizio , Angelini Federico , Fiocco Giorgio
Published: July 2007

Ground‐based measurements of stratospheric constituents were carried out from Thule Air Base, Greenland (76.5°N, 68.7°W), during the winters of 2001–2002 and 2002–2003, involving operation of a millimeter‐wave spectrometer (GBMS) and a lidar system. This work focuses on the GBMS retrievals of stratospheric O3, CO, N2O, and HNO3, and on lidar stratospheric temperature data obtained during the first of the two winter campaigns, from mid‐January to early March 2002. For the Arctic lower stratosphere, the winter 2001–2002 is one of the warmest winters on record. During a large fraction of the winter, the vortex was weakened by the influence of the Aleutian high, with low ozone concentrations and high temperatures observed by GBMS and lidar above ∼27 km during the second half of February and in early March. At 900 K (∼32 km altitude), the low ozone concentrations observed by GBMS in the Aleutian high are shown to be well correlated to low solar exposure. Throughout the winter, PSCs were rarely observed by POAM III, and the last detection was recorded on 17 January. During the lidar and GBMS observing period that followed, stratospheric temperatures remained above the threshold for PSCs formation throughout the vortex. Nonetheless, using correlations between GBMS O3 and N2O mixing ratios, in early February a large ozone deficiency owing to local ozone loss is noted inside the vortex. GBMS O3‐N2O correlations suggest that isentropic transport brought a O3 deficit also to regions near the vortex edge, where transport most likely mimicked local ozone loss.
A comparison of CMAQ‐based aerosol properties with IMPROVE, MODIS, and AERONET data
Authors: Roy Biswadev , Mathur Rohit , Gilliland Alice B. , Howard Steven C.
Published: July 2007

Evaluation of concentrations predicted by air quality models is needed to ensure that model results are compatible with observations. In this study aerosol properties derived from the Community Multiscale Air Quality (CMAQ) model‐simulated aerosol mass concentrations are compared with routine data from NASA satellite‐borne Moderate Resolution Imaging Spectroradiometer (MODIS) sensor aboard the Sun‐synchronous Terra satellite, NASA's ground‐based Aerosol Robotic Network (AERONET), and the ground‐based Interagency Monitoring of Protected Visual Environment (IMPROVE) network. The motivation for this analysis is to determine how best to use these parameters in evaluating model‐predicted PM2.5 concentrations. CMAQ surface extinction estimates due to scattering at 550 nm wavelength are compared with the IMPROVE nephelometer data obtained from 25 sites within the United States. It is found that model‐predicted surface extinctions bear high correlations with nephelometer measured data. Sulfate fractional aerosol optical depth (AOD) is found to dominate in the northeastern part of the United States; hence ground‐based measurement of sulfate concentrations have been compared with time series of columnar AOD as observed by the MODIS instrument and also with the CMAQ‐predicted tropospheric column values obtained during the June–August period of 2001. CMAQ surface extinctions are found to be relatively higher than the IMPROVE nephelometer observations; however, there is a good agreement between CMAQ AOD trends and AERONET and MODIS data, obtained at the seven AERONET sites located in the eastern United States. CMAQ is also found to capture the day‐to‐day variability in the spatial AOD patterns. Monthly average satellite AOD estimates are found to be higher than the AOD data obtained using the CMAQ‐predicted aerosol concentrations. Seasonal variation of satellite‐measured aerosol intensive property “Angstrom exponent” (a gross indicator of the aerosol size distribution) is presented for four selected sites: one each in the eastern and central parts, and two in the western part of the continental United States. Variability of Angstrom exponent at these four selected sites is analyzed in conjunction with the variation of summertime AOD (observed and modeled), mass concentration (observed and modeled) and modeled SO4 average concentrations during the summer (June–August) period of the year 2001. Annual time series of Angstrom exponent data at the four selected sites show a large east‐west variation.
Two‐diffusion description of hyperpycnal deltas
Authors: Lai Steven Y. J. , Capart Hervé
Published: July 2007

Alluvial deltas formed upstream of lakes and reservoirs often exhibit concave foresets with maximum inclinations smaller than the angle of repose. In the present work, we test whether this morphology could be attributed to bed load sediment transport by turbid underflows, acting along the foreset beds before their fine sediment load settles out of suspension. Under hyperpycnal conditions, both the topset and foreset of the delta would thus be subject to the geomorphic influence of the dense river inflow. To describe this joint geomorphic action by subaerial and subaqueous currents, we derive a two‐diffusion theory and modify it to account for inclination thresholds. Different diffusion strengths apply to the topset and foreset, on either side of the moving shoreline. For a channel of uniform initial slope and a constant water level in the body of standing water, we show that the resulting moving boundary problem admits exact similarity solutions. To test the theory, the analytical solutions are compared with small‐scale laboratory experiments in which turbid underflows are replaced by brine currents. The curved profiles predicted by the theory and measured in the experiments resemble those of surveyed deltaic deposits in lakes known to be prone to turbidity currents.
Possible causes of decreasing cloud cover in the Arctic winter, 1982–2000
Authors: Liu Yinghui , Key Jeffrey R. , Francis Jennifer A. , Wang Xuanji
Published: July 2007

Satellite and reanalysis datasets show a decrease in wintertime (Dec., Jan., Feb.) cloud cover over most of the Arctic Ocean from 1982 to 2000. Concurrently, wintertime moisture convergence has decreased significantly over the Nansen Basin and parts of the Barents and Kara Seas (NBK; 75–90°N, 45–90°E). Over this region, correlation coefficients between monthly anomalies in the satellite‐derived cloud cover and moisture convergence in the cold season are large and statistically significant. This reduction in moisture convergence results in a decrease in cloud formation due to weakening cyclone activity over the NBK region. Reduced cloud amount over this area leads to decreased cloud cover over the entire central Arctic because less cloud is advected to other regions. The same mechanism has been observed over northeastern Russia and the Bering Strait area (RBS; 65–75°N, 150–200°E) and is therefore an additional, and perhaps more important, control over cloud cover in the Chukchi/Beaufort Seas and the Laptev Sea region.
VLF observation of long ionospheric recovery events
Authors: Cotts Benjamin R. T. , Inan Umran S.
Published: July 2007

We introduce a new class of Early/fast VLF events with recoveries of up to 20 min, much longer than typical Early/fast and Lightning‐induced Electron Precipitation (LEP) events which recover to pre‐event levels in ≲200 s. Three distinct types of long recovery events are observed, each exhibiting different characteristics, with the observed features of at least some of the event types consistent with the possibility of persistent ionization at altitudes below 60 km as put forth by Lehtinen and Inan (2007).
An S receiver function analysis of the lithospheric structure in South America
Authors: Heit B. , Sodoudi F. , Yuan X. , Bianchi M. , Kind R.
Published: July 2007

We make use of S receiver function to investigate the structure and thickness of the crust and mantle lithosphere in the South American continent and adjacent areas. The Moho discontinuity has been detected at all stations and goes from 18 km beneath the coast of the continent to 80 km in the Andean region. The depth of the lithosphere‐asthenosphere boundary can be clearly detected below those stations that are located on stable areas from 50 km to 160 km. The identification of this phase becomes more difficult when the stations are located near subduction zones. We also observed the base of the subducted oceanic lithosphere down to depths of 220 km.
Earthquakes triggered by slow slip at the plate interface in the Hikurangi subduction zone, New Zealand
Authors: Reyners Martin , Bannister Stephen
Published: July 2007

An earthquake swarm in the crust of the subducted plate in the southern Hikurangi subduction zone in April‐May 2004 was most likely triggered by slow slip at the plate interface directly downdip during the previous year. Double‐difference relocation indicates that the swarm represents incremental slip on adjacent patches of the same fault. A subsequent ML 5.5 earthquake in January 2005 occurred on a separate, deeper fault, sub‐parallel to that of the 2004 swarm, but separated from it by about 1 km. This suggests a rapid decrease in mechanical damage in the slab with depth below the plate interface. The normal faulting observed in both earthquake sequences represents unbending of the subducted plate. Such unbending may be diagnostic of deformation on the deeper edge of a strongly coupled region of the plate interface resulting from adjacent slow slip.
Imaging links between lithospheric architecture and surface geology in the Proterozoic Curnamona Province, Australia
Authors: Williams H. A. , Betts P. G.
Published: July 2007

Potential field (magnetic and gravity) analysis is an effective method to investigate crustal‐scale architecture and provides a means of linking continental‐scale geophysical data sets (e.g., seismic tomography) with detailed geological and geophysical studies. Here, we image deep‐crustal structure of the Proterozoic Curnamona Province, Australia, in aeromagnetic and gravity data sets and establish spatial and temporal links between deep structures and near surface geological features by superimposing first vertical derivative responses on upward continued images. Upward continued gravity and aeromagnetic data show NW–SE, NE–SW, E–W, and N–S oriented long‐wavelength discontinuities and boundaries to anomalies, which we interpret as deep‐seated structures. These structures predate the oldest known tectonic events recorded in outcropping rocks and appear to have been long‐lived, thereby influencing the tectonic history of the province. For example, outcropping Cambrian shear zones, evident in vertical derivative data, appear to have nucleated off displaced segments of a once continuous deep‐seated structure of Proterozoic origin that has been imaged in upward continued data. Long‐wavelength gradients defining E–W and NW–SE structures in upward continued aeromagnetic data intersect beneath the dominantly felsic Benagerie igneous province in the central province and are coincident with a large negative gravity anomaly interpreted as felsic igneous rocks that are coeval to the volcanic pile. Tectonic implications of this study include (1) deep‐seated structures in the Curnamona Province have protracted histories; (2) these structures appear to have controlled the location and distribution of younger shear zones, igneous activity, and possibly basin subsidence in the upper crust; (3) geophysical lineaments are likely to have evolved and propagated during multiple tectonic cycles and hence record the protracted evolution of a geological province.
Cellular requirements for mixed leucocyte reactivity in the cyclostome, Eptatretus stoutii
Authors: Raison Robert L , Gilbertson Peter , Wotherspoon John
Published: July 2007

Unfractionated peripheral blood leucocytes from allogeneic hagfish proliferated vigorously in one‐way mixed leucocyte reaction (MLR) at 20–22°. Maximum responsiveness was observed after 5 days of co‐culture of responder and irradiated stimulator cells. Separation of leucocytes on the basis of laser scatter parameters yielded a small leucocyte population which responded but did not stimulate in MLR and a large leucocyte population capable of stimulating but not responding. Adherent cell depletion of the total leucocyte population did not affect the ability to respond in MLR but did ablate the stimulatory capacity of hagfish leucocytes. Together with previous phenotypic studies, these results confirm the presence of lymphocyte and macrophage/accessory cell populations in hagfish peripheral leucocytes.
The Role of the Colony‐Stimulating Factors in Resistance to Acute Infections
Authors: Metcalf Donald
Published: July 2007

A set of specific glycoproteins, the colony‐stimulating factors, has been identified as regulating granulocyte and macrophage production and function. These colony‐stimulating factors have now been purified and mass produced by recombinant technology. These versatile regulators are capable of providing the body both with an ultrarapid and sustained system for responding to infections. The granulocytes, macrophages and eosinophils involved in these responses appear likely to be key cell populations ensuring adequate resistance to acute infections and the colony‐stimulating factors may prove to be valuable agents in the clinic for increasing resistance to life‐threatening infections particularly in immunologically compromised patients.
Further studies on the heterogeneity of antigens recognised by CD‐1 monoclonal antibodies: distribution of epitopes and analysis of serological binding patterns
Authors: Favaloro EJ , Bradstock KF , Grimsley P , Henniker A , Kamath S
Published: July 2007

The binding patterns of 28 monoclonal antibodies (MAB) recognizing antigens belonging to Cluster of Differentiation One (CD‐1) were analyzed in order to investigate heterogeneity within this cluster. Competitive binding assays using radiolabelled MAB provided detailed information on CD‐1 antigenic heterogeneity, and demonstrated that at least six epitopic regions are recognised as CD‐1 MAB. Further studies, based on single cell suspension immunofluorescence assays (using thymocytes and subclones on the cell line Molt‐4), suggested that the majority of MAB studied could be serologically separated into three groups. In view of the most recent information suggesting that CD‐1 MAB recognize at least three different early T‐cell differentiation molecules, our results indicate that there are three or more distinct epitopes on the ‘gp49’ (HTA‐1/CD‐1a) molecule, two on the ‘gp45’ (HTA‐3/CD‐1b) molecule and one on ‘gp43’ (HTA‐2/CD‐1c).
The inflammatory activity of activated complement in ovine and bovine mammary glands
Authors: Colditz IG , Maas PJCM
Published: July 2007

Infusion of zymosan‐activated plasma (ZAP), a source of activated complement, induced inflammation in non‐lactating mammary glands but not in lactating glands of ewes and cows. Interstitial injection of ZAP in lactating ovine glands also failed to induce inflammation as assessed by the neutrophil content of milk. The inflammatory activity of ZAP in non‐lactating glands was inhibited by infusion of whole milk but not by skimmed milk. These results suggest that components of whole milk mask the inflammatory activity of activated complement. In addition, lactating mammary tissue of ewes and cows may lack sensitivity to the inflammatory effect of activated complement. Thus, activated complement cannot be an important mediator of inflammation in the lactating gland.
Expression of Genes in Cloned Murine Cell Lines that can be Maintained in Both Interleukin 2‐ and Interleukin 3‐Dependent Growth States
Authors: Le Gros Janette E , Jenkins David R , Prestidge Ross L , Watson James D
Published: July 2007

Two cloned murine cell lines. FD.C/1 and 32Dcl‐23 exhibit switching of lymphokine‐dependent growth states. The bone marrow‐derived FD.C/1 and 32Dcl‐23 cell lines are normally grown in culture medium supplemented with inierleukin 3 (IL3). The replacement of IL3 with interleukin 2 (IL2) in the medium results in an increase in IL2 receptor expression in FD.C/1 and 32Dcl‐23 cells and the switching of cells lo an IL2‐dependent growth state. We have compared patterns of protein and phosphoprotein synthesis, as well as the expression of the c‐abl, c‐ras, c‐myb, and c‐fos oncogenes in these cell lines maintained in IL3‐ and I L2‐dependent growth states. The synthesis of a series of proteins and phosphoproteins are identified with each of the lymphokine‐dependent growth states. All of the oncogenes examined are expressed in both IL2‐ and lL3‐dependent cells and are not altered by phenotypic changes in lymphokine growth dependence. The relationship of oncogene expression to intracellular pathways regulated by lymphokine‐receptor interactions is considered.
Gamma‐irradiated influenza A virus can prime for a cross‐reactive and cross‐protective immune response against influenza A viruses
Authors: Müllbacher A , Ada GL , Tha Hla R
Published: July 2007

A‐strain influenza virus A/JAP (H2N2) was tested for its ability to induce cytotoxic T cells (Tc) after being rendered non‐infectious by either UV or gamma irradiation. Gamma‐irradiated virus proved to be more efficient than UV‐inactivated virus in priming for a memory Tc cell response or in boosting memory spleen cells in vitro. Most importantly, γ‐inactivated, but not UV‐inactivated, A/JAP immunized animals survived lethal challenge with heterologous (A/PC(H3N2), A/WSN(H1N1)) virus as effectively as mice primed with infectious virus.
Phagocytosis and transcytosis by the follicle‐associated epithelium of the ileal Peyer's patch in calves
Authors: Landsverk Thor
Published: July 2007

Latex beads, 250 and 610 nm in diameter, and parapox virus isolated from ecthyma in sheep, were injected into intestinal loops containing either jejunal or ileal Peyer's patches (PP) of 3–4 week old calves. Uptake of latex and parapox virus was restricted to the ileal PP, 30–60 min after injection. The latex beads seemed to be embraced by thin surface protrusions extending from the concentric folds of the follicle‐associated epithelial cells (FAE) of the ileal PP. Both latex and virus were internalized into cytoplasmic vacuoles. Some of the vacuoles containing virus showed reaction for acid phosphatase. The latex beads and virus were shed to the intercellular spaces of the FAE. The exocytosis appeared to occur through specialized indentations of the lateral plasma membrane where the production of 50 nm membrane‐bounded particles by budding off from the lateral plasma membrane was a prominent phenomenon.
Production of suppressor factors induced by ultraviolet irradiation or cis‐urocanic acid requires Lyt‐2+ lymphocytes
Authors: Harriott‐Smith Tammy G , Halliday WJ
Published: July 2007

Both ultraviolet (UV) irradiation and cis‐urocanic acid (UCA) are reported to be associated with the suppression of contact hypersensitivity (CHS) and the induction of a soluble factor which suppresses leukocyte adherence inhibition (LAI) assays in vitro. The cellular origin of the suppressor factor (SF) has now been investigated in vivo and in vitro, using monoclonal antibodies against lymphocyte surface markers to deplete certain ceil populations, namely T lymphocytes bearing the L3T4 (helper) and Lyt‐2 (suppressor) markers. Depletion of Lyt‐2+ cells from irradiated mice in vivo and from spleen cell cultures in vitro led to the elimination of detectable levels of SF. Depletion of L3T4+ cells had no such effect. Similarly, Lyt‐2+ cells (but not L3T4+ cells) were shown to be necessary for the production of SF by normal spleen cells cultured with cis‐UCA. These data suggest that the production of SF following UV irradiation may be related to the action of cis‐UCA on Lyg‐2+ lymphocytes.
Membrane proteins stimulated by interferon‐alpha in growth‐inhibited, but not in resistant, Daudi cells
Authors: Quek Alan , Goding James , Hoogenraad Nicholas
Published: July 2007

Interferon‐alpha (α‐IFN) stimulates the expression of a number of plasma membrane proteins in wild‐type Daudi cells. These proteins are not induced in a variant subline of Daudi cells, which is insensitive to growth inhibition, nor in another which is partially growth‐inhibited by α‐IFN. Two‐dimensional polyacrylamide gel electrophoresis of [125I]‐surface labelled Daudi membrane proteins indicates that the major protein induced de novo has a molecular weight of 16 kD(p16), and proteins of 20 kD (p20), 28 kD (p28)and 106 kD (p106) which are present in untreated cells are also induced by α‐IFN.

A monoclonal antibody was produced against p106 by immunizing mice with cells treated for 16 h with α‐IFN followed by differential screening against treated and untreated cells. The antibody (A96/G8) immunoprecipitated p106 from cell lysates and was used to show that p106 is induced approximately two‐fold by α‐IFN in wild‐type Daudi cells, but not at all in Daudi cells which show a complete or partial resistance to growth inhibition by α‐IFN; γ‐IFN does not induce p16 or p106 and also does not inhibit cell growth.

The induction of p16 and p106 precedes the observed inhibition of growth by IFN. The levels of p16 and p106 are elevated by 8·5 hand in the case of p16 continue to rise for 16 h after the addition of IFN, whereas p 106 reaches a peak by 8·5 h. In contrast, growth inhibition is not observed by 8 h and does not become clear‐cut until 24 h after the addition of IFN.
A single dose of UV radiation suppresses delayed type hypersensitivity responses to alloantigens and prolongs heart allograft survival in mice
Authors: Mottram PL , Mirisklavos A , Clunie GJA , Noonan FP
Published: July 2007

The systemic effect of ultraviolet (UV) irradiation on delayed type hypersensitivity (DTH), contact hypersensitivity (CHS) and allograft rejection was investigated in BALB/c mice which had been exposed to a single 1 h treatment with UV radiation (27 kJ/m2) from FS40 sunlamps (60% UVB). After UV irradiation (3–5 days), mice were treated on an unirradiated site with either a subcutaneous injection of allogeneic spleen cells or a topical application of the contact sensitizer oxazolone (OX). The DTH response to allogeneic cells and the CHS response to OX elicited 6 days after immunization were significantly lower in UV‐treated mice than in normal mice. Spleen cells from these animals were transferred intravenously into X‐irradiated (600R) recipients which were immediately challenged with antigen and the DTH or CHS response elicited was determined 24 h later. Recipients of equal numbers of cells from sensitized and normal animals (6×106 from each donor) exhibited positive DTH or CHS responses to the antigen used to sensitize the donor. In contrast, recipients of equal numbers of cells from animals sensitized and UV suppressed to the same antigen showed a suppressed DTH or CHS response. This suppression was antigen‐specific. Treatment of cells from UV suppressed animals, prior to transfer, with complement and cytotoxic anti‐Lyt 2 or anti‐Thy 1·2 monoclonal antibodies abrogated the suppressive ability of these cells, in contrast to cytotoxic treatment with anti‐L3T4 or anti‐Lyt 1 monoclonal antibodies which had no significant effect. The suppressor cells therefore had the phenotype Thy 1·2+, Lyt 2+, L3T4−, Lyt 1−. In a separate series of experiments BALB/c mice, either untreated or given 1 h of UV irradiation 3–5 days previously, were given a heart or skin allograft from a C3H/He donor. The primarily vascularized cardiac allografts survived significantly longer in UV‐irradiated than in normal recipients (median survival time 13 days vs 10 days, P= 0·035), but the survival of C3H/He skin allografts was unaltered in UV mice. No identification of suppressor populations was carried out in the heart allograft recipients. These experiments provide the basis for investigations of the possible role of UV‐induced antigen‐specific suppressor cells in modulating responses to alloantigens.
Antibody responses in the liver and bile of rats injected with horse erythrocytes
Authors: Carter L , Barrington PJ , Jackson GDF
Published: July 2007

The intravenous injection of 1 ml of a 0.1 % (or higher %) suspension of horse red blood cells (HRBC) into rats results in the appearance of high levels of agglutinating activity in bile as well as serum. Lower doses of HRBC induce reduced responses in both fluids, demonstrating that the biliary response is as dose‐dependent as the serum response. The presence of IgM anti‐HRBC antibody forming cells (AFC) in the liver in numbers equivalent to those detected in the spleen at day 6 of the study suggests them to be the most likely source of the biliary antibody. Also, the injection of HRBC into other parenteral sites (intramuscular [i.m.], intraperitoneal [i.p.] and intrathoracic cavity [i.t.]) results in a biliary response which is considered to originate from the IgM‐, IgG‐ and IgA‐ anti‐HRBC AFC detected in the liver, again in numbers approximating those detected in the spleen. Splenectomy of rats immunized i.p., i.m. and i.t. had only a minimal effect on the liver and biliary responses, indicating that AFC arising in peripheral lymphoid tissues can also relocate in the liver. It is concluded that the liver is a major site of antibody synthesis following parenteral immunization leading to substantial levels of antibody being secreted into the gastrointestinal tract.
A plasmin generation method for the determination of tissue plasminogen activator (t‐PA) activity in blood
Authors: Koh SCL , Yuen R , Viegas OAC , Chua SE , Ng BL , Sen DK , Ratnam SS
Published: July 2007

A plasmin generation method to determine tissue plasminogen activator (t‐PA) activity in plasma is described, A protein solution of homogenized fibrin was used as a stimulator in the presence of plasminogen and the plasmin generated was measured by the release of para‐Nitroanilide (p‐NA) from the chromogenic substrate S‐2251. Plasmin generation by 5 iu/mL t‐PA in the presence of 1 CU/mL of plasminogen and 850μg/mL of fibrin solution reaches a peak at about 5 h incubation whilst in plasma, plasmin generation peaks after about 16 h incubation. The highest t‐PA activity in plasma was determined using an assay involving 18 h incubation. In the 21 subjects studied by this method the t‐PA activity at rest ranged from 0·34 to 0·92 iu/mL, with a mean of 0·57 ± 0·15 iu/mL of plasma whilst in the post‐occlusion state the activity ranged from 1·12 to 18·0 iu/mL, with a mean of 5·25 ± 4·49 iu/mL of plasma. We also found that subjects who developed petechiae during occlusion had significantly higher t‐PA activity both at pre‐ and post‐occlusion when compared with those who did not develop petechiae. The t‐PA activity of acid‐treated plasma stored at — 70°C showed no significant changes in activity after 12 weeks of storage when compared with the t‐PA activity of the same plasma tested prior to storage.
Subcellular distribution of class II major histocompatibility antigens in enterocytes of the human and rat small intestine
Authors: Mayrhofer G , Spargo LDJ
Published: July 2007

Class II antigens encoded within the major histocompatibility complex (MHC) have been examined at the ultrastructural level in enterocytes from both man and rat. A protocol has been developed for fixation which, in conjunction with a pre‐embedding indirect immunoperoxidase technique preserves antigenicity of the class II molecules and allows detection of intracellular antigen. Details of the technique are provided and discussed in relation to the general paucity of information available on ultrastructural localization of class II MHC molecules. Class II MHC antigens have been identified on the basolateral cell membranes of enterocytes in both species and they have also been found in association with intracellular organelles that have the appearance of multivesicular bodies and secondary lysosomes. These observations link class II molecules with the endocytic pathway in enterocytes and suggest a possible role in the handling of gut antigens. The findings may have a more general significance in relation to the site of engagement between processed antigen and MHC molecules in specialized antigen‐presenting cells.
Response of microvascular endothelial cells to biological response modifiers
Authors: Hicks C , Breit SN , Penny. R
Published: July 2007

This study investigated in vitro biological response modifiers (BRM) possibly involved in initiation and regulation of human capillary endothelial cell (HCEC) growth. An indicator assay was developed using tritiated thymidine to measure increased DNA turnover. Purified or recombinant BRMs tested singly and in combination included: interferon (IFN; α and γ), tumour necrosis factor (TNF; α and β), transforming growth factor (TGF: α and β). rIL‐1, rIL‐2, pIL‐2, platelet derived growth factor (PDGF) and retinoic acid.

Under limiting serum conditions only rlL‐2 (≥ 10 U/mL) caused proliferation of the cells. γIFN together with TNFα(500 U/mL of each) was cytotoxic.

Under maximal stimulus conditions, a cytostatic effect resulted from exposing HCEC to: α or γ IFN (≥ 1000 U/mL), TGFβ (≥5 ng/mL), rIL‐1 (≥ 0·5 U/mL) and rIL‐1 plus γIFN, γIFN (500 U/mL) plus TNFα exhibited synergism in the Inhibition of proliferation and produced a cytotoxic effect at TNFα concentrations ≥500 U/mL. By contrast, rIL‐2 enhanced proliferation at >5 U/mL. When rIL‐2 was combined with γIFN, an inhibitory effect on proliferation was observed, although to a lesser extent than γIFN alone. Pretreating the cells with 100 U/mL γIFN prior to rIL‐1 or IL‐2 exposure produced no change in the trends observed above. TGFα also stimulated cell proliferation at concentrations ≥0·5 ng/mL. PDGF and retinoic acid had no effect on proliferation in the concentration range 0·5‐10 U/mL.

By investigating the response of HCEC to these BRMs, the nature of, and response to the signals from immune cells in inflammatory disease processes can be better understood.
Mechanisms of human neutrophil‐mediated cartilage damage in vitro: The role of lysosomal enzymes, hydrogen peroxide and hypochlorous acid
Authors: Kowanko IC , Bates EJ , Ferrante A
Published: July 2007

Cartilage is a focal point of attack by cellular and molecular elements of the inflammatory response which occurs in arthritic diseases. Neutrophils damage articular cartilage by degrading matrix components and inhibiting their synthesis. The aim of this study was to elucidate mechanisms of this damage. Human neutrophils were isolated from blood by centrifuging through Ficoll‐Hypaque and granule extract prepared from them. Articular cartilage from adult humans and cattle was maintained in organ culture. Cartilage degradation (release of 35S‐labelled proteoglycan) or synthesis (incorporation of 35S into proteoglycan) was determined after various treatments. Human neutrophils and neutrophil granule extract degraded proteoglycan and inhibited proteoglycan synthesis. The specific leucocyte elastase inhibitor N‐methoxysuccinyl‐(ala)2‐pro‐val‐chloromethylketone (MAAPVCMK) partially reversed these effects. H2O2, a product of the neutrophil respiratory burst, when added directly at 10‐6 mol/L, or generated by glucose oxidase (GO)/glucose inhibited proteoglycan synthesis but had no effect on degradation. Hypochlorous acid (OHCl), a product of the myeloperoxidase (MPO)/H2O2/Cl system at 50 μmol/L degraded proteoglycan and inhibited its synthesis. OHCl, produced by granule extract (as a source of MPO) + GO‐generated H2O2 + Cl− degraded proteoglycan. The results indicate that neutrophil‐mediated proteoglycan degradation and inhibition of synthesis is largely attributable to elastase and secondarily to OHCl, whereas H2O2 impairs synthesis without affecting degradation of proteoglycan.
IgG subclasses responsible for immune clearance in mice infected with Trypanosoma cruzi
Authors: Brodskyn CI , Silva AMM , Takehara HA , Mota I
Published: July 2007

To examine the role of different immunoglobulin subclasses in the immune clearance of Trypanosoma cruzi, mice containing bloodstream trypomastigotes were injected intravenously with immune serum, IgG‐depleted serum, or with the IgG1 or IgG2 fractions and the rate of removal oft he parasites from circulation was determined. Using IgG concentrations similar to those found in the immune serum, the rate of clearance mediated by IgG2 was six‐fold higher than that obtained with IgG1. This difference did not appear to be due to differences in antibody specificity, as Western blotting showed that each isotype recognized a similar set of antigens extracted from the parasite. However, the T. cruzi specific antibody content of the IgG2 was approximately five‐fold higher than IgG1. When the dose of IgG was adjusted to equalize the antibody content, the clearance ability of the IgG1 and IgG2 was very similar. It is concluded that the two subclasses have a similar clearance ability.
Role of intestinal immunization in urinary tract defence
Authors: Husband Alan J , Clifton Vicki L
Published: July 2007

The lack of progress in development of vaccines to stimulate local protection in the urinary tract is attributable in part to the lack of information regarding mechanisms of local immunity and to the difficulty in antigen administration at this site. Experiments reported in this paper indicate that the urinary tract in rats forms part of an effector network linking mucosal organs (the common mucosal immune system). Concomitant immunization of the intestine and urinary tract with ovalbumin resulted in the appearance at both sites of antiovalbumin‐containing cells (ACC) of IgA specificity. The gut origin of ACC in the urinary tract was confirmed by demonstrating in similarly immunized rats abrogation of the urinary tract response by chronic drainage of the thoracic lymphatic duct during the post‐challenge period and by demonstrating the appearance of radiolabelled ACC in the urinary tract after injection of labelled autologous thoracic duct lymphocytes collected during the post‐challenge period. These experiments indicate a role for oral immunization in enhancing the local antibody response in the urinary tract against invading pathogens.
The generation and activation of memory class I MHC restricted cytotoxic T cell responses to influenza A virus in vivo do not require CD4+ T cells
Authors: Liu Y , Müllbacher A
Published: July 2007

The cellular requirements for the generation and activation of anti‐influenza memory class I MHC restricted Tc cell responses were studied by selectively reconstituting lethally irradiated mice. The generation of memory Tc cells was investigated by using unprimed splenocytes to reconstitute infected, lethally irradiated mice; the activation of memory Tc cells was tested by using primed splenocytes to reconstitute uninfected, lethally irradiated mice. It is shown here that depletion of CD4+ T cells from donor cells did not reduce Tc cell responses in recipient mice. Depletion of CD8+ T cells from donor splenocytes prevented the memory Tc cell responses. Thus depletion of CD4+ T cells had no effect on the generation and activation of the memory Tc cells in vivo.
1‐Methylnicotinamide (MNA), a primary metabolite of nicotinamide, exerts anti‐thrombotic activity mediated by a cyclooxygenase‐2/prostacyclin pathway
Authors: Chlopicki S , Swies J , Mogielnicki A , Buczko W , Bartus M , Lomnicka M , Adamus J , Gebicki J
Published: July 2007

Background and purpose:

1‐methylnicotinamide (MNA) has been considered to be an inactive metabolite of nicotinamide. Here we assessed the anti‐thrombotic activity of MNA in vivo.

Experimental approach:

Antithrombotic action of MNA was studied in normotensive rats with extracorporeal thrombus formation (thrombolysis), in renovascular hypertensive rats with intraarterial thrombus formation (arterial thrombosis) and in a venous thrombosis model in rats (venous thrombosis).

Key results:

MNA (3‐100 mg kg−1) induced a dose‐dependent and sustained thrombolytic response, associated with a rise in 6‐keto‐PGF1α in blood. Various compounds structurally related to MNA were either inactive or weaker thrombolytics. Rofecoxib (0.01‐1 mg kg−1), dose‐dependently inhibited the thrombolytic response of MNA, indomethacin (5 mg kg−1) abolished it, while L‐NAME (5 mg kg−1) were without effect. MNA (3–30 mg kg−1) also reduced arterial thrombosis and this effect was abrogated by indomethacin (2.5 mg kg−1) as well as by rofecoxib (1 mg kg−1). MNA, however, did not affect venous thrombosis. In vitro MNA did not modify platelet aggregation nor induce vasodilation.

Conclusions and implications:

MNA displayed a profile of anti‐thrombotic activity in vivo that surpasses that of closely related compounds. MNA inhibited platelet‐dependent thrombosis by a mechanism involving cyclooxygenase‐2 and prostacyclin. Our findings suggest that endogenous MNA, produced in the liver by nicotinamide N‐methyltransferase, could be an endogenous activator of prostacyclin production and thus may regulate thrombotic as well as inflammatory processes in the cardiovascular system.

British Journal of Pharmacology (2007) 152, 230–239; doi:10.1038/sj.bjp.0707383