bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlates of protection induced by live Aro−Salmonella typhimurium vaccines in the murine typhoid model
Authors: HARRISON J. A. , VILLARREAL‐RAMOS B. , MASTROENI P. , DEMARCO DE HORMAECHE R. , HORMAECHE C. E.
Published: November 2003

Live attenuated salmonella vaccines generally confer better protection than killed vaccines. The immune responses in BALB/c mice elicited by immunization with a live attenuated Aro Salmonella typhimurium vaccine given orally, intravenously or subcutaneously were compared with those elicited by killed whole‐cell vaccines (acetone or heat‐treated) given subcutaneously. Live vaccines given by all routes elicited higher interleukin‐2 (IL‐2) and interferon‐γ (IFN‐γ) responses in spleen cells against an alkali‐treated whole‐cell salmonella lysate than did killed vaccines. Live and killed vaccines elicited high total antibody levels to smooth lipopolysaccharide (LPS) (enzyme‐linked immunosorbent assay), but all live vaccine regimes elicited higher IgG2a, suggesting a Th1 response. Oral and intravenous vaccination with live organisms elicited IgA against smooth LPS which subcutaneous vaccination with live or killed salmonellae failed to evoke. Western blots using rough whole‐cell lysates showed that all vaccines elicited a varied anti‐protein response; however, all groups immunized with live organisms recognized three unidentified bands of MW 52 000, 46 000 and 18 000 which were consistently absent in groups immunized with killed organisms. The results indicate that immunization with live aroA salmonellae elicited a Th1 type of response, including bystander T‐cell help to LPS, and a response to proteins not seen in mice that received killed vaccines.
Treatment with anti‐LFA‐1α monoclonal antibody selectively interferes with the maturation of CD4−8+ thymocytes
Authors: REVILLA C. , GONZÁLEZ A. L. , CONDE C. , LÓPEZ‐HOYOS M. , MERINO J.
Published: November 2003

Maturation of T lymphocytes in the thymus is driven by signals provided by soluble factors and by the direct interaction between thymocytes and stromal cells. Although the interaction between T‐cell receptor (TCR) and major histocompatibility complex (MHC) molecules on stromal cells is crucial for T‐cell development, other accessory molecules seem to play a role in this process. In order to better understand the role of lymphocyte function‐associated antigen‐1 (LFA‐1) and intercellular adhesion molecule‐1 (ICAM‐1) molecules in thymocyte maturation, mice were treated from birth with saturating doses of non‐cytolytic‐specific monoclonal antibodies. The effect of this treatment on thymocyte subpopulations and the expression of CD3 and TCR‐αβ by these cells was investigated by flow cytometry. Our data demonstrated that the effective saturation of LFA‐1α chain in the thymus, but not ICAM‐1 or LFA‐1β chain, selectively interfered with the maturation of CD8+ T cells, as manifested by a marked reduction in the frequency of CD4−8+ thymocytes expressing high levels of CD3 and TCR‐αβ. This selective reduction was also observed in peripheral blood mononuclear cells and spleen cells. The analysis of the frequencies of various Vβ TCR showed that CD4−8+ thymocytes were globally affected by the treatment. These results underline the importance of the interaction between LFA‐1 and its ligands in the maturation of CD8+ T cells and document the existence of different molecular requirements for the differentiation of CD4+ and CD8+ T cells.
Transforming growth factor‐β induced by live or ultraviolet‐inactivated equid herpes virus type‐1 mediates immunosuppression in the horse
Authors: CHARAN S. , PALMER K. , CHESTER P. , MIRE‐SLUIS A. R. , MEAGER A. , EDINGTON N.
Published: November 2003

Up to 21 days after exposure to live or ultraviolet‐inactivated equid herpesvirus type‐1 (EHV‐1) autologous serum from ponies caused an immunosuppressive effect if incorporated into T‐cell proliferation assays to EHV‐1. The suppressive factor in the sera of ponies also inhibited T‐cell response to phytohaemagglutinin. Increased levels of circulating activated transforming growth factor‐β1 (TGF‐β1) were detected, and the suppressive activity of the serum could be reversed by antibody to TGF‐β1. In a challenge experiment the ponies which exhibited circulating TGF‐β1 activity succumbed to infection while the ones with similar magnitudes of T‐cell responses, but no TGF‐β1 activity, were protected. A definition of this immunosuppressive mechanism and its mode of induction must be central to the design of vaccines and to an understanding of the pathogenesis of EHV‐1.
Proliferation and apoptosis of follicular lymphocytes: relationship to follicular dendritic cell‐associated clusters
Authors: ORUI H. , YAMAKAWA M. , IMAI Y.
Published: November 2003

Experiments were designed to determine the in vivo cell‐cycle phase of lymphocytes in secondary lymphoid follicles, and whether B‐cell proliferation and apoptosis occur within follicular dendritic cell (FDC)‐associated clusters. Using frozen serial sections of human tonsils, lymphoid follicles were stained to reveal histone H3 mRNA, as an S‐phase marker, using in situ hybridization, and stained immunohistochemically with antibodies against cyclin E as a late G1 phase marker, cyclin B1 and p34cdc2 as S‐G2‐M phase markers, and Ki‐67 as a marker of cycling cells. Each LF was divided into five zones: mantle zone, outer zone, apical light zone, basal light zone and dark zone, with the help of haematoxylin and eosin staining, and a CD23 immunostain. The rate of occurrence of positively labelled cells was calculated by dividing the number of positive cells by the number of all cells in each zone. The cells that were positive for cyclin E, histone H3 mRNA, cyclin B1, p34cdc2, and Ki‐67 were found most frequently in the dark zone (54·5±6·6%, 22·0±5·7%, 36·7±14·5%, 40·0±10·2%, and 59·0±13·4%, respectively), followed by the outer zone (52·7±7·8%, 14·9±4·1%, 22·9±9·7%, 24·9±7·9%, and 44·6±12·3%, respectively), showing that both the outer zone and the dark zone contain many proliferating lymphocytes. Furthermore, FDC‐associated clusters and free lymphocytes were obtained from enucleated germinal centres, using enzymatic digestion. The rates of occurrence of cells that were positive for cyclin B1 and Ki‐67 within the clusters (7·2±1·9% and 37·9±10·5%, respectively) were significantly lower than those of free lymphocytes outside the clusters (22·2±4·0% and 62·8±14·0%, respectively). The rates of occurrence of apoptotic bodies and cells within the clusters, as detected by in situ tailing or in situ nick translation (0·2±0·4% and 0·4±0·4%, respectively) were significantly lower than those outside the clusters (1·1±0·3, 1·6±0·5 %, respectively). These results suggest that FDC‐associated clusters are not the site of proliferation, and that they rarely contain apoptotic bodies and cells of B lymphocytes.
Microbiological status of root‐filled teeth with apical periodontitis
Authors: Molander A. , Reit C. , Dahlén G. , Kvist T.
Published: November 2003

The present study examined the microbiological status of 100 root‐filled teeth with radiographically verified apical periodontitis — the pathology (P) group — and of 20 teeth without signs of periapical pathosis — the technical (T) group. In the P group 117 strains of bacteria were recovered in 68 teeth. In most of the cases examined one or two strains were found. Facultative anaerobic species predominated among these isolates (69% of identified strains). Growth was classified as ‘sparse’ or ‘very sparse’ in 53%, and as ‘heavy’ or ‘very heavy’ in 42%. Enterococci were the most frequently isolated genera, showing ‘heavy’ or ‘very heavy’ growth in 25 out of 32 cases (78%). In 11 teeth of the T group no bacteria were recovered, whilst the remairling nine yielded 13 microbial strains. Eight of these grew ‘very sparsely’. It is concluded that the microflora of the obturated canal differs from that found normally in the untreated necrotic dental pulp, quantitatively as well as qualitatively. Nonsurgical retreatment strategies should be reconsidered.
The effect of sterilization on bending and torsional properties of K‐files manufactured with different metallic alloys
Authors: Canalda‐Sahli C. , Brau‐Aguadé E. , Sentís‐Vilalta J.
Published: November 2003

The purpose of this study was to assess the effect of dry‐heat or autoclave sterilization on the resistance to fracture in torque and angular deflection and the resistance to bending of K‐type files made of nickel‐titanium (Nitiflex, Naviflex), titanium (Microtitane) or stainless steel (Flexofile, Flex‐R).

Ten K‐type files of each sort, from size 25 to 40, were tested, according to ANSI/ADA specification 28 (1988) and ISO specification 3630 (1992). Sterilization with dry heat and autoclave slightly decreased the flexibility of files made of stainless steel and nickel‐titanium for most of the sizes, although the values obtained satisfied ISO specifications. The files made of titanium showed an increased flexibility after sterilization with autoclave (sizes 30 and 35) and dry heat (sizes 30, 35 and 40). Resistance to fracture varied amongst the five groups of files tested as follows: it decreased in some sizes of stainless‐steel instruments, decreased in all sizes of titanium files assessed by the torsional moment, and either increased or decreased in some sizes of nickel‐titanium files. All files tested, however, satisfied relevant standards for angular deflection after being subjected to sterilization with an autoclave or dry heat.
Antimicrobial effect of irrigant combinations within dentinal tubules
Authors: Heling I. , Chandler N. P.
Published: November 2003

The aim of this study was to investigate sodium hypochlorite (with and without EDTA), chlorhexidine, and hydrogen peroxide in varying concentrations when used in sequence or in combination as endodontic irrigants. Sterile saline served as the control. Six standardized bovine incisor root specimens, which had been infected with Enterococcus faecalis (CG 110), were exposed to each solution. Following exposure to the test agents dentine samples were taken from within the lumina using ISO 023 to 035 burs. The dentine powder samples were incubated and the quantity of bacteria present assessed using spectrophotometry. All irrigant regimens were more effective than saline in killing bacteria. Chlorhexidine and sodium hypochlorite were similarly effective. At specific concentrations a synergistic effect was noted when mixtures of chlorhexidine and hydrogen peroxide were under test.
Comparison of two endodontic handpieces during the preparation of root canals in extracted human teeth
Authors: Smith R. B. , Edmunds D. H.
Published: November 2003

This in vitro study compared and assessed two endodontic handpieces during the preparation of root canals in extracted human teeth. Eighty extracted human teeth, with single root canals, were divided into eight matched groups. They were prepared using Shaper files activated by the MM1500 Sonic Air handpiece (Micro‐Mega, Besançon, France) or Excalibur files activated by the W & H Excalibur 969 handpiece (W & H, Bürmoos, Austria). The files were 21 mm or 25 mm in length. When preparing the canals, the files were used either in line with or perpendicular to any canal curvature. Preparation of the canals was carried out using the techniques described in the manufacturers' literature. A variety of parameters were used to compare the hand‐pieces, including canal preparation time, deformation or fracture of instruments, loss of canal length, weight loss from the prepared teeth and the overall postpreparation canal shape. A microradiographic technique was used to produce a tracing record of the pre‐ and postpreparation canal shape. Both handpieces provided an efficient and easy method of preparing and shaping the root canal with little operator fatigue. The MM1500 Sonic air handpiece took significantly more time (P <0.001) to prepare the canals than the Excalibur.

Few aberrations in the shapes of prepared canals were created by either handpiece. No endodontic file fractured but a few of them were permanently deformed. The effects of two variables — file length and the plane of use of the file — on performance of the handpieces, were also assessed.
Evaluation of characterization methods for thin sections of silver halide microcrystals by analytical electron microscopy
Authors: GREGORY C. , GIJBELS R. , JACOB W. , GEUENS I. , VAN ROOST C. , DE KEYZER R.
Published: November 2003

Silver halide microcrystals are usually composed of different phases with varying halide compositions. These microcrystals can be sectioned with an ultramicrotome with a certain thickness in a specific direction. The scanning electron microscopical analysis of these sections provides information on the internal halide profile.

During sample sectioning, many deformations can be induced in the material, and usually dominate the different scanning electron images.

By acquiring X‐ray maps, it is possible to locate the different phases in the sections. This technique, however, is very time‐consuming, and can only be used when the local halide variations are very high.

When an EDX line scan is acquired over the section, information on the position of the phases with different halide composition is obtained in a reasonable time, and shows no dependence on the section deformations. From this knowledge, several positions on the section are selected where local X‐ray analyses are performed. After quantifying the results, the internal halide distribution is obtained. The analytical lateral resolution is about 30 nm for sections ≈100 nm thick.
Estimation of subcellular organelle volume from ultrathin sections through centrioles with a discretized version of the vertical rotator
Authors: Mironov A. A. , Mironov A. A.
Published: November 2003

A method for the fast and efficient estimation of the volume (but not surface area) of subcellular organelles is presented. It consists of a rotator/coaxial‐section approach based on the Pappus theorem and represents a discretized version of the vertical rotator where, instead of measuring intercept lengths, the points in distance classes are counted. Centrioles serve as a unique reference ‘double‐point’ with constant size allowing unbiased cell selection from the whole population with equal probability and without the disector application. The sandwich‐like method of sample preparation allows comparison of control and experimental cases with the same errors caused by overlapping and overprojection. Test experiments demonstrated that the vertical discretized rotator was an efficient and precise tool for the estimation of volume and that a few independent sections of unknown thickness were sufficient for the quantification of one experimental point.
Scanning tunnelling microscopy imaging of [3 × 3] Mn nonanuclear grids
Authors: Weeks L. , Thompson L. K. , Shapter J. G. , Pope K. J. , Xu Z.
Published: November 2003

The scanning tunnelling microscopy imaging of [3 × 3] Mn(II) nonanuclear grids on gold substrates is described. Self‐assembled behaviour is observed at both high and low coverage, with submolecular resolution of individual molecules displayed at low deposition concentrations. The importance of proper image processing techniques is demonstrated in resolving the layer structure at high coverage.
A simple method to ‘point count’ silt using scanning electron microscopy aided by image analysis
Authors: Ware C. I.
Published: November 2003

This study presents a simple method to ‘point count’ silt‐sized grains using backscattered scanning electron microscopy together with image analysis. The work materialized out of the need to determine the heavy mineral abundance within silt obtained from coastal dunes to aid in the interpretation of dune weathering. This technique allows two broad mineral groups to be quantified according to their modal abundance. The groups are characterized by their dominant atomic elements present; atomic numbers > 20 are classified as ‘high’ (metal oxides, zircon, monazite, carbonates, pyroxenes and amphiboles) and those < 20 as ‘low’ (quartz, feldspars and organics). As a check on this technique, X‐ray fluorescence was used. This showed a strong positive correlation (r2 = 0.85) with the developed point counting technique.
Three‐dimensional visualization of insect morphology using confocal laser scanning microscopy
Authors: Klaus A. V. , Kulasekera V. L. , Schawaroch V.
Published: November 2003

Cuticular structures of insects are often microscopic and intricately complex; among the most complex structures are male genitalia. Genitalic structures are essential in taxonomic and phylogenetic studies of insects. Using well‐described species from two disparate dipteran genera, we demonstrate the utility of confocal laser scanning microscopy for studying the morphological characters of fly genitalia by taking advantage of the autofluorescent properties of cuticle material. Reconstructions of confocal data sets obtained from genitalic structures embedded in two commonly used entomological mounting media (euparal and glycerin jelly) are presented. Aberration artefacts often observed in confocal data obtained from thick specimens were analysed and strategies for their minimization are discussed. Our results indicate that confocal laser scanning microscopy and 3D reconstruction are excellent techniques for visualizing small, complex, autofluorescent structures in flies. These techniques could have a profound impact on the quality of information provided by 3D representations of insect structures over more traditional methods of visualization.
An association between activity of the Na/K‐pump and resistance of Schistosoma mansoni towards complement‐mediated killing
Authors: TARRAB‐HAZDAI REBECA , CAMACHO MARCELA , MENDELOVIC FELA , SCHECHTMAN DEBORAH
Published: November 2003

The Na/K‐pump or Na+/K+‐ATPase (EC 3.6.1.37), couples the hydrolysis of ATP to the active transport of Na+ and K+ ions across the plasma membrane of virtually all animal cells. The relationship between activity of the Na+/K+‐ATPase and the sensitivity of Schistosoma mansoni to immunological attack has been investigated. It has been observed that ouabain, the specific inhibitor of the pump, via a synergistic effect with specific antibody and complement, affects the average membrane potential causing depolarization and death of complement resistant parasites. Thus, apparently, there is association between the inhibition of the Na/K‐pump and the lysis and death of the complement‐resistant parasite.
Spatio‐temporal development of pycnidia and perithecia and dissemination of spores of Mycosphaerella pinodes on pea (Pisum sativum)
Authors: ROGER C. , TIVOLI B.
Published: November 2003

The pattern of development of pycnidia and perithecia of Mycosphaerella pinodes was studied in the glasshouse on pea plants (cv. Solara) sprayed with a pycnospore suspension and in field plots inoculated with barley grains colonized by the fungus. The numbers of pycnidia and perithecia were estimated on each stipule and internode of infected plants, and were related to ratings of disease severity (0–5 scale). Pycnidia were produced on both green and senescent organs, whereas perithecia only appeared on senescent organs. The development and quantity of pycnidia were related to initial inoculum concentration and the physiological stage of the plants. The formation of fruiting bodies progressed from the bottoms to the tops of plants during crop development. Spore trapping showed that both pycnospore dispersal and ascospore discharge were initiated by rainfall or dew. Pycnospores were principally trapped in the first 20 cm above the soil surface while ascospores were also trapped above the crop canopy. Pycnospores and ascospores were dispersed throughout the growing season, suggesting that ascospores also play an important role in secondary infections.
The incorporation of pathogen spores into rain‐splash droplets: a modelling approach
Authors: HUBER L. , FITT B. D. L. , McCARTNEY H. A.
Published: November 2003

Simple, theoretical, physical principles and existing experimental data were used to derive an analytical model to describe the incorporation of plant pathogen spores into splash droplets. Data were obtained from experiments on splash dispersal of spores of Pseudocercosporella herpotrichoides (cereal eyespot), Pyrenopeziza brassicae (oilseed rape light leaf spot) and Septoria nodorum (wheat glume blotch). In these experiments, incident drops of diameter 4–5 mm were allowed to fall onto spore suspensions 0.5 mm deep with 1.2 × 105 to 6.5 × 105 spores/mL. The analytical model was constructed as the product of three functions of droplet diameter which described, respectively, the frequency distribution of droplet diameters, the proportion of droplets carrying spores and the mean number of spores in spore‐carrying droplets in each diameter category. The frequency distribution of droplet sizes was described by a log‐normal distribution, the proportion of droplets carrying spores was described by an exponential function and the adimensional spore concentration in spore‐carrying droplets was described by a power law. The cumulative proportions of spores in droplets in diameter categories of increasing diameter were calculated to compare observed and fitted data.
Identification of whitefly transmitted tomato yellow leaf curl geminivirus from Iran and a survey of its distribution with molecular probes
Authors: HAJIMORAD M. R. , KHEYR‐POUR A. , ALAVI V. , AHOONMANESH A. , BAHAR M. , REZAIAN M. A. , GRONENBORN B.
Published: November 2003

A virus causing a disease of tomato, prevalent in the southern provinces of Iran, with symptoms of leaf‐curling, stunting, reduction of leaf size, leaf corrugation, shortening of internodes and severe reduction in fruit yield, was shown to be transmissible to healthy tomato plants by grafting and by whiteflies (Bemisia tabaci), but not by sap inoculation. Geminivirus DNA was detected in extracts of diseased tomato plants by dot‐blot hybridization assays using as probes full‐length cloned DNA of Australian, Italian (Sardinian) or Jordanian strains of tomato yellow leaf curl virus (TYLCV). Geminivirus coat protein was detected in whitefly inoculated plants by dot immunobinding assay using polyclonal antibody raised against Jordanian TYLCV. A limited survey using the dot‐blot hybridization assay for virus detection indicated the presence of the virus in tomato‐growing provinces of southern but not northern Iran. Whitefly transmission experiments to tomato under controlled greenhouse conditions showed that some isolates of TYLCV‐like geminiviruses from different parts of Iran differ in symptomatology.
The pattern of fungal contamination of the banana bunch during its development and potential influence on incidence of crown‐rot and anthracnose diseases
Authors: De LAPEYRE de BELLAIRE L. , MOURICHON X.
Published: November 2003

Anthracnose and crown rot are the main diseases affecting bananas after harvest. These diseases are mainly caused by Colletotrichum musae (anthracnose) and to some extent by various Fusarium species forming a fungal complex (crown rot). A water‐borne spore trap was used to collect and quantify all inocula reaching banana bunches from flowering to harvest. The pattern of natural contamination was characterized by a peak from 25 to 40 days after bunch emergence, with a strong decline until harvest. Both Colletotrichum and Fusarium species had the same dynamics during bunch growth. Flower parts are the main inoculum source for Fusarium; both flower parts and the last bunch bract are important sources for Colletotrichum. Primary inoculum could reach flower parts and the last bunch bract through rain splash of conidia, transport by insects or aerial dissemination of ascospores. Sporulation occurring on the young flower parts and on the last bunch bract provides heavy secondary inoculum. The consequences for control strategies are discussed.
Complement Subcomponent C1q Modulation of TNF‐α Binding to L929 Cells for Enhanced TNF‐Mediated Cytotoxicity
Authors: JIANG HONG , ZHOU ANQIANG , HERRIOTT M. J. , RUMMAGE J. A. , STEWART C. A. , FAST D. J. , LEU R. W.
Published: November 2003

Complement subcomponent C1q has been recently implicated in the modulation of autocrine binding of TNF‐α to murine macrophages for induction of nitric oxide synthase. In the present study, the putative role of C1q in increasing TNF‐α binding to L929 cells to mediate cytotoxicity was explored. TNF‐sensitive L929 cells (L929‐S) had higher total endogenous cellular and surface C1q levels and bound correspondingly more phycoerythrin‐labelled rTNF‐α (PE‐TNF) than did a TNF‐resistant L929 variant (L929‐R). Pretreatment of L929‐S with soluble C1q increased their sensitivity to TNF‐mediated cytotoxicity coincident with increased binding of PE‐TNF, but similar treatment of L929‐R had no effect. Pretreatment of L929‐S with an inhibitor of C1q secretion, 3,4 dehydro‐D,L‐proline (DHP), resulted in a decrease in their TNF‐mediated cytotoxicity, as well as reduced binding of PE‐TNF. Subsequent exposure of DHP‐treated L929‐S with exogenous soluble C1q restored their TNF‐mediated cytotoxicity and binding of PE‐TNF. These results provide evidence for the modulation of TNF‐α binding to TNF sensitive tumour targets L929 by either endogenously synthesized or exogenously added C1q to promote TNF‐mediated cytotoxicity by mechanisms which remain to be elucidated.
The Cell Surface Phenotype of Human Natural Interferon‐α Producing Cells as Determined by Flow Cytometry
Authors: SVENSSON H. , JOHANNISSON A. , NIKKILÄ T. , ALM G. V. , CEDERBLAD B.
Published: November 2003

The relationship between the so‐called natural interferon‐α (IFN‐α) producing cell (IPC), stimulated to produce IFN‐α by herpes simplex virus type 1 (HSV), and of dendritic cells (DC) in peripheral blood leucocytes was investigated. The simultaneous expression of cell surface antigens and intracellular IFN‐α in the HSV‐stimulated IPC (HSV‐IPC) was examined by flow cytometry (FCM). The HSV‐IPC were infrequent, <0.3% of the mononuclear leucocytes, and with homogeneous light scatter characteristics. The HSV‐IPC were confirmed to lack leucocyte lineage specific markers, and to express CD4, CD36 and HLA‐DR. Furthermore, they expressed high levels of CD44, CD45RA and CD45RB, and lower levels of CD40, CD45R0, CD72 and CD83. The HSV‐IPC expression of CD13, CD33 and FcεRI were weak but significant, while no CD5, CD11b, CD16, CD64, CD80 or CD86 were detected. Sorted pure HSV‐IPC had irregular shaped nuclei, many mitochondria and vesicles, and rugged cell membranes without veils. Sorted HSV‐IPC stimulated proliferation of autologous T cells from HSV immune donors. Thus, the HSV‐IPC in many respects resemble immature DC, but clearly differ from typical mature DC. However, they may also represent a specialized population of efficient IFN‐α producing cells.
Functional Differences in the Specific B‐Cell Compartment in High or Low Antibody Responder Mice
Authors: DE FRANCO M. , VIDARD L. , MOUTON D. , DECREUSEFOND C. , GILLE PERRAMANT M.‐F. , COUDERC J.
Published: November 2003

The role of antigen‐presenting cells (APC) in quantitative antibody synthesis regulation was studied in mice genetically selected for high (HI) or low (LI) antibody response. Irradiated spleen cells and enriched specific B cells from HI and LI mice co‐isogenic at H‐2 s locus, were compared for their capacity to present chicken ovalbumin (OVA) to specific T‐cell hybridomas. Minor differences were observed between HI and LI mice when three distinct hybridomas were stimulated in the presence of OVA and splenic macrophages APC. These differences were totally abolished when APC were pulsed with OVAxAb complexes. Looking at the B‐cell compartment, hybridoma IL‐2 responses were similar when TNP primed B cells were pulsed with OVA. However, when OVA was targeted on TNP‐specific enriched B cells by pulsing with TNP‐OVA, the IL‐2 production by the T‐cell hybridomas was stronger in the presence of HI B cells than in the presence of LI B cells. These results strongly suggest that an efficient Ag handling/processing by specific B cells is a major component of the high Ab responder status in Biozzi mice.
A Human In Vitro Granuloma Model Using Heat Killed Candidaalbicans Cells Immobilized on Plastic Culture Wells
Authors: HEINEMANN D. E. H. , PETERS J. H. , GAHR M.
Published: November 2003

A new model for studying the initial events of granuloma formation in vitro is presented using heat killed Candida albicans immobilized on the surface of plastic culture wells. Human monocytes were induced to accumulate and to proliferate, forming multinucleated giant cells (MGC) and epitheloid cells within 4 days of culture. Tumour necrosis factor‐α (TNF‐α), interleukin (IL)‐1β and IL‐6 were detected in culture supernatants. These monokines, and additionally macrophage colony stimulating factor (M‐CSF), were also detected immunocytochemically. The granuloma formation was inhibited by Dexamethasone (Dex), Pentoxifylline (POF), or interferon‐γ (IFN‐γ) in a dose‐dependent manner. Antibodies to M‐CSF reduced the granuloma formation to a great extent with a striking reduction of monocyte proliferation. Using antibodies to TNF‐α the authors found a complete inhibition of the granuloma including MGC formation and monocyte proliferation.
A Cryopreservation Method of Human Peripheral Blood Mononuclear Cells for Efficient Production of Dendritic Cells
Authors: MAKINO M. , BABA M.
Published: November 2003

The establishment of a cryopreservation method for unstimulated fresh peripheral blood mononuclear cells (PBMC) with nearly 100% viability would greatly contribute to the conduct of various immunological experiments. The cells most sensitive to freezing and thawing procedure seem to be dendritic cells (DC) and their precursors, which are of the most potent antigen‐presenting cells. The authors investigated and established a method of cryopreserving fresh PBMC from which DC were recovered and differentiated efficiently by using recombinant (r) GM‐CSF and rIL‐4. PBMC frozen in the presence of 12% dimethylsulfoxide and 25–30% fetal calf serum recovered DC as efficiently as freshly obtained PBMC. Established DC could also be cryopreserved in the presence of 12% DMSO with their viability maintained at more than 90%. The 12% DMSO freezing solutions were superior to both the 10% DMSO solution and the previously reported DC freezing medium (2 m or 15.4% DMSO). The DC obtained from the cryopreserved PBMC expressed HLA‐DR, HLA‐DQ, CD80 and CD86 antigens, and stimulated allogenic PBMC to an extent almost identical to that obtained from fresh PBMC. These findings indicate that the conditioned medium utilized here enables safe cryopreservation of DC and DC precursors in PBMC.
Biological Effects of the Immunomodulator β1‐3d Polyglucose are Strongly Potentiated by Conjugation to Biodegradable Microbeads
Authors: SELJELID R. , GAO Q. , BERGE A. , UGELSTAD J.
Published: November 2003

It is demonstrated that the biological effects of the immunomodulator β1‐3d polyglucose, when covalently linked to polymethacrylate or biodegradable albumin microbeads, are strongly potentiated. The potentiation is recorded as an increased protection effect of the conjugates in Escherichia coli sepsis in mice, and as increased IL‐1 production by murine macrophages in vitro.
Study on medical donor deferrals at sessions
Authors: Galea G. , Gillon J. , Urbaniak S. J.
Published: November 2003

A 10‐month audit of reasons for donor medical deferral at sessions was carried out in two Scottish regions of the SNBTS. Six thousand deferred donors were assessed. Although the deferred donor population mirrored the attending donor population in both regions, significantly more donors, both new and regular, were deferred in the Edinburgh and South East region, compared with the North East. The main differences in deferral were attributable to three clinical conditions (cervical carcinoma in situ, other gynaecological conditions and hypertension) and to donors admitting to high‐risk behaviour. Although the staff in the deferral process — doctors, nurses and clerks — were involved in roughly equal proportions in both regions, the spectrum of medical conditions seen by each staff grouping appeared to be different in each region. The staff in the South East appeared to have made more correct decisions. Further analysis and audits are being undertaken in areas highlighted by this study.
Yersinia enterocolitica transmission from a red cell unit 34 days old
Authors: McDonald C. P. , Barbara J. A. J. , Hewitt P. E. , Hartley S. , Telfer P. , Gale R. , James E. , Prentice H. G.
Published: November 2003

In 1993 the North London Blood Transfusion Centre received its first report of Yersinia enterocolitica transmission from a unit of red cells supplied to a local hospital. The recipient was a 23‐year‐old male who was neutropenic following a third cycle of chemotherapy for treatment of acute myeloblastic leukaemia (FAB type M6) and received a 34‐day‐old red cell unit. During transfusion the patient developed septicaemia and endotoxin‐mediated shock. The transfusion was stopped immediately and broad spectrum antibiotics administered immediately on suspicion of bacteraemia from the transfused unit. This prompt action undoubtedly prevented a fatal outcome.  Y. enterocolitica was isolated from the blood bag. Antibody was also detected in the bag and in a sample taken from the donor 39 days post‐donation. Antibody to serotype 03 was identified, the commonest serotype reported in transfusion‐transmitted Y. enterocolitica. The donor reported no gastrointestinal upset or illness prior to donation.  This transfusion reaction might not have occurred had the red cells been transfused earlier in their storage period, but would not have been prevented by the exclusion of donors with a history of gastrointestinal illness as the donor was asymptomatic. Nor would it have been prevented by inspecting the blood for a change in colour, as no such change was observed.  Y. enterocolitica is a significant problem in transfusion medicine and transmission is generally associated with a high mortality rate. Hospitals should be urged to investigate bacteriologically all appropriate transfusion reactions so that the true extent of the problem in the United Kingdom can be assessed.
Striae distensae of pregnancy. An in vivo biomechanical evaluation
Authors: Henry Frédérique , Piérard‐Franchimont Claudine , Pans Alain , Piérard Gérald E.
Published: November 2003

Background and objective Striae distensae of pregnancy is a common finding. There is currently a lack of information about the rheological characteristics of such lesions. The purpose of this study was to compare the mechanical properties of striae distensae before and after delivery.

Patients and methods A total of 79 primigravid entered the study. Rheological properties of skin were evaluated in vivo using a Cutometer® equipped with a 2‐mm probe.

Results Mechanical properties of striae distensae developing during pregnancy resembled those of the surrounding skin. By contrast, significant differences were yielded during post‐partum. Extensibility of striae distensae was increased although parameters of elasticity remained normal.

Conclusions Rheological properties of striae distensae of pregnancy vary in time. This might reflect the changes in hormones and in the mechanical stresses normally setting the skin under tension.
Persistence of photosynthetic components and photochemical efficiency in ears of water‐stressed wheat (Triticum aestivum)
Authors: Martinez Dana E. , Luquez Virginia M. , Bartoli Carlos G. , Guiamét Juan J.
Published: November 2003

Ear photosynthesis may be an important source of C for grain growth in water‐stressed plants of cereals. The main objectives of this work were to determine the stability of the photosynthetic apparatus and the photochemical efficiency of ears in plants subjected to post‐anthesis drought. Plants of wheat (Triticum aestivum L. cv. Granero INTA) were grown in pots under a rain shelter and subjected to water stress (soil water potential around −0.6 to −0.8 MPa) starting 4  days after anthesis. Post‐anthesis drought substantially accelerated the loss of chlorophyll, Rubisco and the light‐harvesting complex of photosystem II (LHCII) in the flag leaf, but the degradation of these photosynthetic components was much less affected by water deficit in awns and ear bracts. Quantum yield of PSII (ΦPSII) decreased in leaves of water‐stressed plants. In contrast, ear bracts had a higher ΦPSII than leaves, and ΦPSII of ear bracts did not decrease at all in response to drought. Removing the grains immediately before fluorescence measurements (less than 30 min) slightly reduced ΦPSII, indicating that CO2 supplied by grain respiration may contribute to the high photochemical efficiency of ears in droughted plants. However, other factors may be involved in maintaining high ΦPSII, since even in the absence of grains ΦPSII remained much higher in ear bracts than in the flag leaf. The relative stability of ear photosynthetic components and their relatively high photochemical efficiency may help to maintain ear photosynthesis during the grain filling period in droughted plants.
Daily and infradian rhythms of circumnutation intensity in Helianthus annuus
Authors: Buda Agnieszka , Zawadzki Tadeusz , Krupa Maciej , Stolarz Maria , Okulski Witold
Published: November 2003

Circumnutation in Helianthus annuus L. was investigated by measurements lasting 4–7 weeks using a picture analysis system. The rhythmicity of circumnutation vigour (intensity) with regard to the trajectory length and period of individual circumnutations were examined. Three photoperiod conditions were applied [light/dark (LD), continuous light (LL) and LD followed by LL]. Data were processed by the Fourier analysis. Statistical analysis included the examination of circumnutation mean frequencies and correlation tests. Both parameters, trajectory length and period, revealed a daily (24 h) modulation in LD with a weak correlation between them, whereas in LL no daily modulation of the parameters was observed. After LD–LL transition, the parameters were gradually losing their daily modulation. Despite a very strong modulation of the trajectory length in LD, the period was quite stable in all groups tested, but only in LD were there no statistical differences in the number of circumnutations per 24 h among the plants studied. LD was concluded to be the strong synchronizer, making the plants circumnutate regularly. Regardless of the presence or absence of daily modulation, the infradian (several and more days long) harmonics of the trajectory length were the same in each group. These findings strongly support the view that circumnutation in sunflower, widely known as an ultradian rhythm, also possesses daily and infradian modulations of its intensity. To the authors' knowledge, this is the first report of circumnutation that was obtained by a picture analysis system in such a large timescale.
The calpain 1–α‐actinin interaction
Authors: Raynaud Fabrice , Bonnal Chantal , Fernandez Eric , Bremaud Laure , Cerutti Martine , Lebart Marie‐Christine , Roustan Claude , Ouali Ahmed , Benyamin Yves
Published: November 2003

Calpain 1 behaviour toward cytoskeletal targets was investigated using two α‐actinin isoforms from smooth and skeletal muscles. These two isoforms which are, respectively, sensitive and resistant to calpain cleavage, interact with the protease when using in vitro binding assays. The stability of the complexes in EGTA [Kd(–Ca2+) = 0.5 ± 0.1 µm] was improved in the presence of 1 mm calcium ions [Kd(+Ca2+) = 0.05 ± 0.01 µm]. Location of the binding structures shows that the C‐terminal domain of α‐actinin and each calpain subunit, 28 and 80 kDa, participates in the interaction. In particular, the autolysed calpain form (76/18) affords a similar binding compared to the 80/28 intact enzyme, with an identified binding site in the catalytic subunit, located in the C‐terminal region of the chain (domain III–IV). The in vivo colocalization of calpain 1 and α‐actinin was shown to be likely in the presence of calcium, when permeabilized muscle fibres were supplemented by exogenous calpain 1 and the presence of calpain 1 in Z‐line cores was shown by gold‐labelled antibodies. The demonstration of such a colocalization was brought by coimmunoprecipitation experiments of calpain 1 and α‐actinin from C2.7 myogenic cells. We propose that calpain 1 interacts in a resting state with cytoskeletal targets, and that this binding is strengthened in pathological conditions, such as ischaemia and dystrophies, associated with high calcium concentrations.
Cholecystokinin rapidly stimulates CrkII function in vivo in rat pancreatic acini
Authors: Andreolotti Alberto G. , Bragado Maria J. , Tapia Jose A. , Jensen Robert T. , Garcia‐Marin Luis J.
Published: November 2003

Crk belongs to a family of adapter proteins whose structure allows interaction with tyrosine‐phosphorylated proteins and is therefore an important modulator of downstream signals, representing a convergence of the actions of numerous stimuli. Recently, it was demonstrated that cholecystokinin (CCK) induced tyrosine phosphorylation of proteins related to fiber stress formation in rat pancreatic acini. Here, we investigated whether CCK receptor activation signals through CrkII and forms complexes with tyrosine‐phosphorylated proteins in rat pancreatic acini. We demonstrated that CCK promoted the transient formation of CrkII–paxillin and CrkII–p130Cas complexes with maximal effect at 1 min. Additionally, CCK decreased the electrophoretic mobility of CrkII. This decrease was time‐ and concentration‐dependent and inversely related with its function. Carbachol and bombesin also decreased CrkII electrophoretic mobility, whereas epidermal growth factor, vasoactive intestinal peptide, secretin or pituitary adenylate cyclase‐activating polypeptide had no effect. CCK‐induced CrkII electrophoretic shift was dependent on the Src family of tyrosine kinases and occurred in the intact animal, suggesting a physiological role of CrkII mediating CCK actions in the exocrine pancreas in vivo.
Factors involved in the assembly of a functional molybdopyranopterin center in recombinant Comamonas acidovorans xanthine dehydrogenase
Authors: Ivanov Nikolai V. , Hubálek Frantisek , Trani Manuela , Edmondson Dale E.
Published: November 2003

Previous work from this laboratory has shown that the spectral and functional properties of a prokaryotic xanthine dehydrogenase from Comamonas acidovorans show some similarities to those of the well‐characterized eukaryotic enzymes isolated from bovine milk and from chicken liver [Xiang, Q. & Edmondson, D.E. (1996) Biochemistry35, 5441–5450]. Therefore, this system was chosen to study the factors involved in the expression of functional recombinant enzyme in Escherichia coli to provide insights into the assembly of the functional Mo‐pyranopterin center. Genes xdhA and xdhB (encoding the two known subunits of the native enzyme) and putative genes xprA and ssuABC were sequenced. Heterologous expression of the xdhAB genes in E. coli JM109(DE3) produced active enzyme. The Mo content was 0.11–0.16 mol per αβ protomer, while the Fe and FAD levels were at stoichiometries similar to that of the native enzyme. The XDH activity increased sixfold when the culture was grown under conditions of low aeration (6 L·min−1) as compared with high aeration (12 L·min−1). Co‐expression of the xdhAB genes with the Pseudomonas aeruginosa PA1522 (xdhC) gene increased the level of Mo incorporated into the expressed enzyme to a 1 : 1 stoichiometry. Under these conditions, high levels of functional protein (2.284 U·mg−1 and 8.039 mg·L−1 of culture) were obtained independently of the level of culture aeration. Therefore, the assembly of a functional Mo‐pyranopterin center in XDH requires the presence of a functional xdhC gene product. The purified, recombinant XDH shows spectral and kinetic properties identical to those of the native enzyme.
Mikrographisch kontrollierte Chirurgie (3D‐Histologie) beim Melanom
Authors: Möhrle Matthias
Published: November 2003

Die mikrographisch kontrollierte Chirurgie (3D‐Histologie) wird im englischen Sprachraum nach ihrem Begründer Frederic E. Mohs überwiegend als Mohs Micrographic Surgery (MMS) bezeichnet. Methoden der 3D‐Histologie kamen bislang bei verschiedenen Hauttumoren zum Einsatz. Die 3D‐Histologie ist indiziert bei Tumoren, die sich per continuitatem ausbreiten. Exzisionen mit 3D‐Histologie erfolgen mit primär kleineren Sicherheitsabständen. Hierbei können gesundes Gewebe geschont und bessere kosmetische Ergebnisse erzielt werden.

Verschieden Verfahren der 3D‐Histologie, wie die Technik nach Mohs (MMS) und die „Tübinger Torte”, werden im Vergleich zur konventionellen histopathologischen Aufarbeitung vorgestellt. Der Stellenwert der 3D‐Histologie beim Melanom wird anhand der bisher publizierten Arbeiten diskutiert.

Auch wenn prospektiv‐randomisierte Untersuchungen zur 3D‐Histologie beim Melanom fehlen, sollte die 3D‐Histologie bei Lentigo‐maligna‐Melanomen grundsätzlich eingesetzt werden. An funktionell bedeutsamen Arealen (Gesicht, Hand, Fuß) ist bei reduzierten Sicherheitsabständen der Einsatz der 3D‐Histologie auch bei anderen histologischen Melanomtypen sinnvoll.
Characterization of alfalfa germplasm expressing resistance to silverleaf whitefly, Bemisia argentifolii
Authors: Jiang Y. X. , Zareh N. , Walker G. P. , Teuber L. R.
Published: November 2003

Abstract:  Thirty‐eight plants were taken from a University of California alfalfa selection nursery for developing resistance to silverleaf whitefly, Bemisia argentifolii Bellows & Perring. Seventeen of the plants had low whitefly infestation and were categorized as ‘potentially resistant’; 21 of the plants had high whitefly infestation and were categorized as ‘presumed susceptible’. Plants were propagated vegetatively so that replicated measurements of whitefly performance could be made on each genotype. Two colonies of silverleaf whiteflies were used: one reared on alfalfa (alfalfa‐experienced whiteflies), and the other on cotton (alfalfa‐naive whiteflies). The effect of variation among alfalfa genotypes on whitefly performance was similar for both whitefly sources, although on all genotypes, the alfalfa‐experienced whiteflies generally performed better than their alfalfa‐naive counterparts. In greenhouse tests, fecundity of newly eclosed adults (over a 5‐day period) on the 17 potentially resistant genotypes was relatively consistent in being lower than fecundity on the presumed susceptible genotypes. However, in nymphal survival tests, the response on the 17 potentially resistant genotypes was not consistent. Nymphal survival (egg to adult) on some of these was very low, as expected, while nymphal survival on others was as high as on the presumed susceptible genotypes. Fecundity and nymphal survival data were not correlated for alfalfa‐naive whiteflies, and were only weakly correlated (r2 = 0.13, d.f. = 32, P = 0.04) for alfalfa‐experienced whiteflies. Thirteen genotypes then were examined in the greenhouse in stage‐specific survival tests, where four genotypes demonstrated high resistance (<10% nymphal survival) and three demonstrated moderate resistance (11–34% survival) compared with the three presumed susceptible genotypes that were tested (51–73% survival). Most of the mortality on the resistant genotypes occurred in the first instar, while mortality was more evenly distributed across the life stages on the susceptible genotypes. Interestingly, if nymphs survived to second instar on the resistant genotypes, then their subsequent survival to adult eclosion was similar to survival of second instar to adult on susceptible genotypes. Six of the genotypes used in the greenhouse stage‐specific survival test also were evaluated in the field for nymphal survival, and these results were consistent with the greenhouse tests.