bluuebunny/crossref_metadata_2025 huggingface dataset:
Induction of interferon regulatory factors, 2′‐5′ oligoadenylate synthetase, P68 kinase and RNase L in chronic myelogenous leukaemia cells and its relationship to clinical responsiveness
Authors: Fischer Thomas , Aman Javad , Van DerKuip Heiko , Rudolf Gregor , Peschel Christian , Aulitzky Walter , Huber Christoph
Published: October 2003

The genes crucially determining the therapeutic response of chronic myelogenous leukaemia (CML) to interferon‐alpha (IFN‐alpha) are unknown. Recently, two independent IFN‐alpha signalling pathways were identified: the classic pathway mediates induction of 2′‐5′ oligoadenylate synthetase (2‐5 OAS), p68 kinase and IFN regulatory factor‐2 (IRF‐2), whereas the alternate pathway leads to activation of IFN regulatory factor‐1 (IRF‐1). We investigated whether deficient or imbalanced expression of components of these two pathways is associated with resistance of CML cells to antiproliferative action of IFN‐alpha/beta. Constitutive and IFN‐induced transcript levels of IFN‐dependent genes in mononuclear cells, granulocytes, monocytes, lymphocytes and CD34+ cells of chronic‐phase CML and blast crisis patients were assessed by Northern blot techniques and were correlated with subsequent clinical responses to IFN therapy. Our results demonstrated that IFN‐alpha or ‐beta treatment in vitro and in vivo leads to an enhanced expression of IRF‐1, IRF‐2, RNase L, p68 and 2‐5 OAS which was independent of the degree of cellular differentiation and clonal evolution of CML. Neither the magnitude of induction of these genes nor the IRF‐1/IRF‐2 mRNA balance differed between chronic‐phase CML patients responding or failing IFN‐alpha therapy. These results indicate that failure of IFN‐alpha treatment is not due to defects in mRNA induction of the above‐mentioned candidate genes for the direct antiproliferative response to IFN type I.
The GIMEMA ALL 0183 trial: analysis of 10‐year follow‐up
Authors: Mandelli Franco , Annino Luciana , Rotoli Bruno
Published: October 2003

We report the 10‐year follow‐up of the GIMEMA ALL 0183 trial.

From 1983 to 1987, 358 adults with acute lymphoblastic leukaemia (ALL) were entered into this trial, which included a mild induction, an early intensive consolidation, a post‐consolidation phase randomized in conventional maintenance (arm A) and in more intensive regimen (arm B). CNS prophylaxis did not include CNS irradiation. The overall complete remission (CR) rate was 79.3% (284/358); 212 patients were randomized (110 in arm A and 102 in arm B).

The median overall CR duration was 20 months and the median overall survival (OS) 21 months; both curves reach a plateau after 6 years; at 10 years 25% of patients were projected to be in long‐term remission and survivors. The median disease‐free survival (DFS) was 17 months, at 10 years 27% and 28% of patients were DFSs in arm A and in arm B respectively.

In multivariate analysis age, WBC count and L2 FAB subtype were found to significantly influence OS and DFS. With regard to our previous report OS appears to linearly correlate with initial WBC count and age (P=0.0002 and P=0.042 respectively).

195 (68.7%) patients relapsed (only 25 had isolated CNS). The overall second CR rate was 56.5%; 23 patients underwent transplantation (12 BMT and 11 ABMT). Post‐relapse survival was found to be influenced by the duration of first CR.
Allogeneic marrow transplantation for aplastic anaemia associated with dyskeratosis congenita
Authors: Langston Amelia A. , Sanders Jean E. , Deeg H. Joachim , Crawford Stephen W. , Anasetti Claudio , Sullivan Keith M. , Flowers Mary E. D. , Storb Rainer
Published: October 2003

Eight patients with aplastic anaemia associated with dyskeratosis congenita received allogeneic marrow grafts from either HLA‐identical siblings (six patients) or HLA‐matched unrelated donors (two patients). Patients who received marrow from HLA‐identical siblings were conditioned with cyclophosphamide (140–200 mg/kg), with or without antithymocyte globulin. Patients who received unrelated donor marrow were conditioned with cyclophosphamide (120 mg/kg) and total body irradiation (1200 cGy). The six patients who survived for >2 weeks following transplant all had haematological evidence of engraftment, and all three patients who survived for at least a year following transplant recovered normal haematological function. Three patients died with respiratory failure and pulmonary fibrosis at 70 d, 8 years and 20 years post‐transplant; three patients died during the neutropenic period of invasive fungal infections; one patient died on day 44 of refractory acute graft‐versus‐host disease; and one patient remains alive 463 d following transplant. The surviving patient recently underwent surgical resection of a Dukes' stage C rectal carcinoma diagnosed 14 months post‐transplant.

The aplastic anaemia associated with dyskeratosis congenita can be successfully treated by allogeneic bone marrow transplantation; however, this approach does not reverse the other systemic manifestations of the syndrome. The pathogenesis of the interstitial lung disease observed in dyskeratosis congenita patients following marrow transplantation is not understood.
Differential effects of the antifolates methotrexate, aminopterin and trimetrexate on murine haemopoietic progenitor cells
Authors: Strømhaug A. , Slørdal L. , Warren D. J.
Published: October 2003

We investigated the effects of the antifolates methotrexate (MTX), aminopterin (AMT) and trimetrexate (TMTX) on murine haemopoietic progenitor cells. Colony formation by late progenitors (CFU‐C) was inhibited by the antifolates and the addition of leucovorin (LV) to the cultures on day 0 or day 5 wholly or partially reversed the effects of MTX or AMT. The effect of TMTX was only effectively rescued by hypoxanthine plus thymidine (HT). In the high proliferative potential colony forming cell (HPP‐CFU‐C) assay the antifolates induced formation of smaller colonies, but not a reduction in absolute colony numbers. This effect was reversed by LV and indicated that the antifolates (except high TMTX concentrations) were not toxic to the HPP‐CFU‐C but reversibly inhibited proliferation of more mature progenitor cells. The direct effects of the drugs on HPP‐CFU‐C were investigated in limiting dilution assays performed with fractionated bone marrow cells. Untreated cultures contained almost only large colonies, whereas the addition of antifolates induced a reversible shift towards smaller colonies. The present study indicates that MTX, AMT and low TMTX concentrations are not toxic to HPP‐CFU‐C but that the drugs induce a developmental arrest in more mature progenitor cell populations.
Comparison of cell proliferation in the centre and advancing fronts of oral squamous cell carcinomas using Ki‐67 index
Authors: Dissanayake U. , Johnson N. W. , Warnakulasuriya K. A. A. S.
Published: October 2003

Abstract.  The cell proliferation status of 60 oral squamous cell carcinomas from Sri Lankan subjects was examined by immunohistochemistry using the Ki‐67 index. A comparison was made between the indices derived from the centre of the tumours and those derived from the invasive fronts of the same tumours. There was a positive correlation between the two indices suggesting a clonal expansion of malignant cells, but the mean index derived for the invasive fronts (29.75  11.64) was significantly higher than the mean index for the body of these tumours (25.65  11.64). Thus, at a given time, more peripheral cells at the invasive front are proliferating and this compartment is likely to be more informative in prognostic and other behavioural studies involving the cell cycle. In squamous carcinomas, increased and uncontrolled cell proliferation at the invasive front may be one feature contributory to the invasion.
Expression of intercellular adhesion molecules on circulating lymphocytes in relation to different manifestations of cow's milk allergy
Authors: Österlund P. , Smedberg T. , Schröder J. , Järvinen K.‐M.
Published: October 2003

BackgroundThe complex interactions between immune cells are partly mediated by different adhesion molecules, but little is known about their role in the systemic immunoinflammatory process following sensitization to food antigens in early infancy.

ObjectiveThe aim of this study was to investigate the expression of intercellular adhesion molecule‐1 (ICAM‐1or CD54) and the α subunits of its ligands' lymphocyte function‐associated antigen‐1 (LFA‐1) (αLsubunit or CD11a) and Mac‐1 (αMsubunit or CD11b) on peripheral blood leucocytes in infants with cow's milk allergy (CMA) and in healthy controls.

MethodsThirty‐nine breastfed infants, aged from 0.6 to 8.3 months, and their lactating mothers were included in the study from delivery onwards. During follow‐up, 25 infants developed CMA and 14 remained healthy. Expressions of CD54 and CD11b on peripheral blood leucocytes were evaluated by flow cytometry. In addition, the expression of CD11a on peripheral blood leucocytes was analysed by immunocytochemistry. Mothers' milk samples were collected and their leucocyte content was evaluated using a light microscope.

ResultsThe frequency of ICAM‐1 expressing peripheral blood lymphocytes was significantly higher in patients with CMA than in healthy infants (P=0.03, Mann–WhitneyU‐test). Furthermore, the high proportion of ICAM‐1‐expressing cells was associated with gastrointestinal and multiorgan symptoms in the CMA infants. There was no significant difference in the expression of Mac‐1 αMon lymphocytes in our study groups, but the LFA‐1 αLexpression seemed to be higher in the IgE‐mediated CMA.

ConclusionWe suggest that the high expression of ICAM‐1 on peripheral blood lymphocytes may reflect enhanced stimulation of T cellsin vivoand their migration to the effector tissues in an early‐phase of developing CMA. Furthermore, high ICAM‐1 expression may be associated with the presence of multiorgan manifestations of CMA, whereas high LFA‐1 expression may reflect the IgE‐mediated disease.
A rapid microbiopsy system to improve the preservation of biological samples prior to high‐pressure freezing
Authors: Vanhecke D. , Graber W. , Herrmann G. , Al‐Amoudi A. , Eggli P. , Studer D.
Published: October 2003

A microbiopsy system for fast excision and transfer of biological specimens from donor to high‐pressure freezer was developed. With a modified, commercially available, Promag 1.2 biopsy gun, tissue samples can be excised with a size small enough (0.6 mm × 1.2 mm × 0.3 mm) to be easily transferred into a newly designed specimen platelet. A self‐made transfer unit allows fast transfer of the specimen from the needle into the specimen platelet. The platelet is then fixed in a commercially available specimen holder of a high‐pressure freezing machine (EM PACT, Leica Microsystems, Vienna, Austria) and frozen therein. The time required by a well‐instructed (but not experienced) person to execute all steps is in the range of half a minute. This period is considered short enough to maintain the excised tissue pieces close to their native state. We show that a range of animal tissues (liver, brain, kidney and muscle) are well preserved. To prove the quality of freezing achieved with the system, we show vitrified ivy leaves high‐pressure frozen in the new specimen platelet.
An oscillating cryo‐knife reduces cutting‐induced deformation of vitreous ultrathin sections
Authors: Al‐Amoudi A. , Dubochet J. , Gnaegi H. , Lüthi W. , Studer D.
Published: October 2003

A new oscillating cryo‐knife for producing uncompressed vitreous sections is introduced. The knife is a modified cryo diamond knife that is driven by a piezo translator. Optimal setting for the oscillation was found to be in the inaudible frequency range of 20–25 kHz. Yeast cells and polystyrene spheres were used as model systems to describe compression in the vitreous sections. We found that compression could be reduced by a factor of about 2 when the knife was oscillating. When the oscillator was turned off, sections were compressed by 40–45%. However, only 15–25% compression was obtained when the knife was oscillating. In some cases completely uncompressed sections of yeast cells were produced. It was also found that the amount of compression depends on the specimen itself and on its embedding medium. With the results shown here, we demonstrate that the oscillating knife can produce high‐quality vitreous sections with minimum cutting artefacts.
Influence of maternal infection on offspring immune response in murine larval toxocariasis
Authors: Reiterová K. , Tomašovicová O. , Dubinský P.
Published: October 2003

The impact of Toxocara canis infection on the proportion of CD4+ and CD8+ T splenocytes, the serum concentrations of cytokine IFN‐γ and IL‐5, and the production of Toxocara‐specific antibodies were studied in two C57BL6/J mouse groups and their offspring. The mice were infected with 1000 T. canis eggs on the day of mating (early infection) and on day 14 of pregnancy (late infection). Early infection resulted in a significant increase of CD4+ T‐cell subtype, however, a decline in CD8+ in comparison with late infection, as well as with non‐infected control. The IFN‐γ serum concentrations decreased in infected mothers after the birth when compared with non‐infected mothers, while in the offspring this cytokine was barely or not detectable. In the mothers of both infected groups, the humoral immune response included both parasite‐specific IgM and IgG2 antibodies. While IgG1 levels remained constant throughout the whole experiment in mothers with early infection, late‐infected mothers became seropositive only 3 weeks after delivery. IgM was not detectable in any offspring. Pups from early‐infected mothers had IgG1 antibodies. Conversely, IgG2 was detectable in pups of both experimental infection groups. A significant difference was observed in the amounts of pups/litter of the infected mothers in comparison with the non‐infected ones. Only 56% of females after early infection and 79% of those after late infection had a successful pregnancy. However, all mice of the control group produced a litter. The first T. canis larvae were detected in the muscles of the offspring of both groups on day 5 after the birth. These data show the changes in regulatory and cytotoxic immunity mechanisms of the infected mothers and their offspring and the high level of pregnancy loss as a result of larval toxocariasis.
Cytokine gene expression in dams and foetuses after experimentalNeospora caninuminfection of heifers at 110 days of gestation
Authors: Almeria S. , De Marez T. , Dawson H. , Araujo R. , Dubey J. P. , Gasbarre L. C.
Published: October 2003

Neospora caninumis a major cause of abortion in cattle. An essential role for Th1 cytokines, such as IFN‐gamma and IL‐12 in protective immunity againstN. caninumin murine models has been indicated. However, little is known about immunity toNeosporain pregnant cattle where a considerable level of immunomodulation may exist. In this study, the immune response of heifers infected early in the second trimester of pregnancy by intravenous inoculation ofN. caninumtachyzoites was compared with immune responses in uninfected pregnant heifers. Animals were killed 3 weeks after infection. No abortion was observed in any infected dam, however, transplacental infection was shown to have already taken place. Infection withN. caninumduring pregnancy induced significant immune responses in both dams and their foetuses. Infected dams showed significant changes in lymphocyte subpopulations compared with uninfected pregnant animals and these changes were compartmentalized. Increased levels of T lymphocytes were observed in the infected foetuses. Cytokine gene expression analysed by real time RT‐PCR showed increased expression of both Th1 and Th2 cytokines inN. caninuminfected animals. This cytokine expression could have a role in the transplacental transmission of the parasite and/or mediate tissue damage.
Rare variants of Cutaneous Leishmaniasis: Whitlow, paronychia, and sporotrichoid
Authors: Iftikhar Nadia , Bari Irfan , Ejaz Amer
Published: October 2003

Cutaneous Leishmaniasis is endemic in certain areas of Pakistan, with the wet form of the disease being the most prevalent. It has a number of morphological variants, which are dependant on the immune status of the host, the subspecies of the Leishmania, and also, to some extent, on the site of involvement. We describe here a case of Leishmaniasis showing two very rare variants, whitlow and paronychial lesions, occurring concurrently with sporotrichoid spread. The patient responded to intramuscular sodium stibogluconate with resolution of the skin lesions.
Diagnostic performance and retention of acquired skills after dermatology elective
Authors: Enk Claes D. , Gilead Leon , Smolovich Irena , Cohen Robert
Published: October 2003

Background   The dermatology elective often constitutes the future physician's only exposure to dermatologic practice. Cost–benefit considerations dictate that the elective enables the students to acquire useful diagnostic expertise in the short time period available, and that this expertise is not rapidly forgotten after completion of the elective.

Methods   In order to determine the efficacy of a 2‐week dermatology elective in promoting diagnostic skills and to ascertain the preservation of the acquired expertise, kodachrome slide‐based multiple‐choice examinations were administered to 84 sixth year medical students at the beginning (pre‐test) and completion (post‐test) of the elective. The long‐term retention of diagnostic skills was evaluated by re‐testing 4–9 months after completion of the elective (follow‐up test).

Results   The mean scores of correct answers at the pre‐ and post‐test were 39.73% and 72.46%, respectively. The mean score at the follow‐up test for students with a previous dermatology elective was 80.22%, compared with a score of 46.00% for students who did not participate in the elective.

Conclusions   The 2‐week dermatology elective significantly improved the diagnostic skills of the participants, and the knowledge obtained during the elective was retained for at least 4–9 months.
Characterization of ubiquitin‐like polypeptide acceptor protein, a novel pro‐apoptotic member of the Bcl2 family
Authors: Nakamura Morihiko , Tanigawa Yoshinori
Published: October 2003

Monoclonal nonspecific suppressor factor (MNSF) is a cytokine with antigen nonspecific suppressive activity. MNSFβ (a subunit of MNSF) is a 14.5 kDa fusion protein consisting of a protein with 36% identity with ubiquitin and ribosomal protein S30. The ubiquitin‐like segment (Ubi‐L) may be cleaved from MNSFβ in the cytosol. Recently, we have observed that Ubi‐L covalently binds to intracellular proteins in mitogen‐activated murine T‐helper type 2 clone, D.10 cells. In this study, we purified a 33.5 kDa Ubi‐L adduct from D.10 cell lysates by sequential chromatography on DEAE, anti‐(Ubi‐L) Ig–conjugated Sepharose, and hydroxylapatite. MALDI‐TOF‐MS fingerprinting revealed that this Ubi‐L adduct consists of an 8.5 kDa Ubi‐L and a Bcl2‐like protein, murine orthologue of a previously cloned human BCL‐G gene product with pro‐apoptotic function. Murine Bcl‐G mRNA was highly expressed in testis and significantly in spleen. In addition, the level of Bcl‐G mRNA expression was increased in concanavalin A‐ and interferon γ‐activated D.10 cells. The 33.5 kDa Ubi‐L adduct was expressed in spleen but not in testis, even though Bcl‐G protein was highly expressed in this tissue. The antisense oligonucleotide to Bcl‐G significantly decreased the level of the Ubi‐L adduct formation in concanavalin A‐activated D.10 cells and the proliferative response of the D.10 cells. These results suggest that the post‐translational modification of Bcl‐G by Ubi‐L might be implicated in T‐cell activation.
Dimerization and oligomerization of the chaperone calreticulin
Authors: Jørgensen Charlotte S. , Ryder L. Rebekka , Steinø Anne , Højrup Peter , Hansen Jesper , Beyer N. Helena , Heegaard Niels H. H. , Houen Gunnar
Published: October 2003

The chaperone calreticulin is a highly conserved eukaryotic protein mainly located in the endoplasmic reticulum. It contains a free cysteine SH group but does not form disulfide‐bridged dimers under physiological conditions, indicating that the SH group may not be fully accessible in the native protein. Using PAGE, urea gradient gel electrophoresis, capillary electrophoresis and MS, we show that dimerization through the SH group can be induced by lowering the pH to 5–6, heating, or under conditions that favour partial unfolding such as urea concentrations above 2.6 m or SDS concentrations above 0.025%. Moreover, we show that calreticulin also has the ability to self‐oligomerize through noncovalent interactions at urea concentrations above 2.6 m at pH below 4.6 or above pH 10, at temperatures above 40 °C, or in the presence of high concentrations of organic solvents (25%), conditions that favour partial unfolding or an intramolecular local conformational change that allows oligomerization, resulting in a heterogeneous mixture of oligomers consisting of up to 10 calreticulin monomers. The oligomeric calreticulin was very stable, but oligomerization was partially reversed by addition of 8 m urea or 1% SDS, and heat‐induced oligomerization could be inhibited by 8 m urea or 1% SDS when present during heating. Comparison of the binding properties of monomeric and oligomeric calreticulin in solid‐phase assays showed increased binding to peptides and denatured proteins when calreticulin was oligomerized. Thus, calreticulin shares the ability to self‐oligomerize with other important chaperones such as GRP94 and HSP90, a property possibly associated with their chaperone activity.
Shade facilitates an invasive stem succulent in a chenopod shrubland in South Australia
Authors: LENZ TANJA I. , FACELLI JOSÉ M.
Published: October 2003

Abstract  The invasive stem succulent Orbea variegata (L) Haw. (Asclepiadaceae) tends to be more abundant underneath shrubs than in open areas in chenopod shrublands near Whyalla, South Australia. To assess the role of facilitation in the life cycle of O. variegata, we investigated the effect of chenopod shrubs on different life stages of the species by experimentally manipulating temperature, light, soil moisture and nutrient levels. Experimental results suggest that the reduction in light and temperature under shrubs, but not increased nutrient levels, are the main facilitative mechanisms for O. variegata. Temperatures above 30°C, which are more likely to occur on the soil surface of open areas than under shrubs, inhibited seed germination. Seedling survival at low watering frequency and the growth of established ramets were increased by 75–80% shade cloth. Ramets growing in full light contained a high concentration of anthocyanin pigments. One of the functions of these pigments is to absorb excess radiation, suggesting that O. variegata experiences radiation stress in full light. In the field O. variegata performed considerably better under Atriplex vesicaria Heward ex Benth. (Chenopodiaceae) or under 75–80% shade cloth than in full light. Monthly irrigation of 20 mm did not reduce this positive effect of the A. vesicaria canopy on O. variegata, suggesting that O. variegata is inhibited by high light intensities or temperatures, independent of water availability. In conclusion, whereas shrub canopies do not seem to be required for the establishment or survival of O. variegata, shrubs improve adult growth and can improve establishment. The possibility of exotic plants being facilitated by other plants has to be taken into account when assessing the probability and rate of invasion.
Seed size and survival in the soil in arid Australia
Authors: MOLES ANGELA T. , WARTON DAVID I. , WESTOBY MARK
Published: October 2003

Abstract We investigated the relationship between seed size and seed survival in the soil in 67 species from arid Australia. There was a very weak, marginally significant positive relationship between the viability of fresh seeds and diaspore mass. However, by the time seeds had been buried in the soil for 1 year in nylon mesh bags, there was a highly significant positive relationship between diaspore mass and diaspore viability. Over the range of seed masses observed, a tenfold increase in diaspore mass was associated with a threefold increase in the odds of surviving 1 year of burial in the soil. Thus, large‐seeded species were favoured over small‐seeded species during this important selective process. However, the magnitude of this advantage was small compared with the advantage experienced by small‐seeded species during seed production. We also investigated aspects of diaspore morphology in relation to viability retention during burial. We found no relationship between seed survival and the amount of protective tissue per unit diaspore surface area. Diaspore mass was a better predictor of survival than was diaspore surface area.
Chronic Experiences with a Single Lead Dual Chamber Implantable Cardioverter Defibrillator System
Authors: NIEHAUS MICHAEL , DE SOUSA MARCOS , KLEIN GUNNAR , KORTE THOMAS , PFEIFFER DIETRICH , WALLES THORSTEN , RAYMONDOS KONSTANTINOS , TEBBENJOHANNS JUERGEN
Published: October 2003

Monitoring of atrial rhythm in patients implanted with ICDs may improve accuracy in identifying supraventricular arrhythmias and, therefore, prevent inappropriate therapies. Since difficulties were found in dual chamber ICDs with separate leads, a new designed single lead dual chamber ICD system was tested. Twenty‐five patients implanted with a Deikos A+ (single coil defibrillation lead with two atrial sensing rings combined with a dual chamber ICD with a high amplifying atrial channel) were tested. Atrial and ventricular signals were analyzed during sinus rhythm (SR) and sinus tachycardias (STs), atrial flutter and AF, and VT or VF. Follow‐ups were performed after 1, 3, 6, 9, and 12 months after implantation. Analysis of EGM amplitudes of stored episodes revealed that atrial signals during atrial flutter (2.1 ± 0.51 mV) were comparable to those of ST (2.2 ± 0.5 mV). Atrial amplitudes during AF were significantly lower (0.81 ± 0.5 mV, P < 0.01). During VF atrial “sinus“ signals (2 ± 0.8 mV) were stable. Ventricular parameters did not differ from a standard ICD lead; defibrillation threshold was 11.4 ± 4.5 J (16 patients). During intraoperative and prehospital discharge measurements, 97.1% of SR‐P waves and 99.2% of atrial flutter waves were detected correctly. In AF 91.11% of atrial signals were detected. Analysis of 505 stored episodes showed that 96.8% of ST and 100% of atrial flutter and 100% of AF episodes have been classified correctly and no underdetection of VT/VF was found. The first experiences with the new VDD‐ICD system show an increase of the specificity to detect ventricular tachycardias to a level comparable to dual chamber ICDs with two leads. The reliability of this system has to be proven in a prospective randomized study. (PACE 2003; 26:1937–1943)
Resynchronization Therapy After Congenital Heart Surgery to Improve Left Ventricular Function
Authors: ROOFTHOOFT MARCUS T.R. , BLOM NICO A. , RIJLAARSDAM MARRY E.B. , BÖKENKAMP REGINA , OTTENKAMP JAAP , SCHALIJ MARTIN J. , BAX JEROEN J. , HAZEKAMP MARK G.
Published: October 2003

This report describes the mid‐term beneficial hemodynamic effect of biventricular pacing in an infant with congestive heart failure after congenital heart surgery, due to resynchronization of the left and right ventricle, optimization of the AV delay, and (partial) correction of the LV dyssynchrony. (PACE 2003; 26:2042–2044)
Rostellar apparatus of Fernandezia spinosissima (von Linstow, 1894) (Cestoda, Cyclophyllidea, Davaineidae): microanatomy and fine structure
Authors: Stoitsova Stoyanka R. , Georgiev Boyko B. , Vasileva Gergana P. , Jordanova Mimi
Published: October 2003

The rostellar apparatus of Fernandezia spinosissima is examined by light and transmission electron microscopy. It is described as composed of rostellum, pseudoproboscis, and two groups of glandular syncytia, one in the rostellum and the other inwards to the rostellum and the pseudoproboscis. The rostellum is a discoid cushion with muscular walls. There are numerous thin vertical muscular fibres and glandular syncytia inside it. Its tegument has slender microtriches. Peripherally, the rostellum is encircled by thin muscle fibres that protrude anteriorly between rostellar hooks and group posteriorly to form retractors. The rostellar hook guards are associated with a complicated network of muscles and nerves. The pseudoproboscis is a thick‐walled ring around the apical part of the scolex adjacent to the rostellum. Its tegument has microtriches with modified spines that are interpreted as accessory spines. The walls of the pseudoproboscis possess a loose structure of parallel muscular fibres and glandular processes. The glandular syncytia, interpreted as modified tegumental perikarya, have basophilic cytoplasm and stain positively for protein and carbohydrate. They form cellular processes, which protrude to reach to the tegument. These results provide structural details characterising one of the rostellar types recognized in the order Cyclophyllidea, i.e. the davaineid rostellar apparatus.
Mixing barley cultivars affects aphid host plant acceptance in field experiments
Authors: Ninkovic Velemir , Olsson Ulf , Pettersson Jan
Published: October 2003

Four barley varieties with no significant difference in aphid acceptance were sown in pure stands and in pairwise combinations with varieties side by side in separate rows. Settling tests were done in situ in the field plots with apterae of Rhopalosiphum padi (L.) (Homoptera:Aphididae) and showed that aphid acceptance was changed in some combinations of cultivars. In a laboratory test, in which plants of one cultivar were exposed to air from the other cultivars, aphid acceptance was significantly reduced in three of the four cultivars when treated with air from certain other cultivars. Two of these three cultivars showed the same reduction under field conditions. This supports the hypothesis that plant/plant communication may release responses in neighbouring plants that change aphid host plant acceptance. The results also show that this mechanism is not restricted to optimal growing conditions in the laboratory, although it may be modified under field conditions depending on plant genotype.
Contrasting responses to object orientation and illumination by the blowflies Chrysomya chloropyga and Lucilia sericata
Authors: Smith K.E. , Howard J.J. , Wall R.
Published: October 2003

The alighting response of two species of blowfly, Chrysomya chloropyga (Weidemann) and Lucilia sericata (Meigen) (Diptera: Calliphoridae), were considered in relation to the orientation and illumination of a flat, oblong visual object. A strong response to orientation was displayed by L. sericata with the greatest number alighting on the vertical object; there was no significant effect of orientation on the number of C. chloropyga which alighted. Both species alighted preferentially on the more strongly illuminated side of a vertical object. With the object horizontal and more strongly illuminated from below, C. chloropyga again landed on the most brightly illuminated side. In contrast, reducing the brightness on the upper surface of the horizontally‐suspended object reduced the number of L. sericata alighting on the upper surface but also reduced the overall catch, suggesting that for L. sericata the response to the illumination of a surface does not outweigh its response to its orientation. The implications of these results for the development of trapping technology for the monitoring or control of these economically important pest species is discussed.
Behavioural plasticity in support of a benefit for aggregation pheromone use in Drosophila melanogaster
Authors: Wertheim Bregje , Dicke Marcel , Vet Louise E.M.
Published: October 2003

We explored behavioural plasticity in the use of aggregation pheromone in the fruit fly Drosophila melanogaster Meigen (Diptera: Drosophilidae). Based on previous field observations, we formulated two hypotheses on a benefit of using aggregation pheromone for aggregated oviposition. One hypothesis concerns a benefit to the females themselves, where reduced harassment by males can enhance oviposition rate; the other concerns a benefit to their offspring, where larvae can exploit arduous substrates more efficiently. We derive contrasting expectations on the strength of the behavioural response to pheromone for substrates that differ in nutritional quality to larvae. High quality substrates relax the strength of larval competition, which allows for stronger aggregative responses of the females, but conversely, it may yield aggregation less necessary when the benefit is related to resource exploitation by the larvae. In indoor and outdoor dual choice set‐ups, we tested the behavioural responses of the adults to the aggregation pheromone with substrates of varying quality, and examined oviposition behaviour. The response of adults to the aggregation pheromone was strong and robust for low quality substrates, but significantly weaker for a high quality substrate. This supports the hypothesis on a benefit to the larvae. Females retained aggregation pheromones in the absence of oviposition substrates for at least 24 h. In the outdoor set‐up, substrate with aggregation pheromone received more than three times as many eggs as control substrates, and this was directly related to the number of adults that visited each substrate. Per capita, oviposition rates were not different for differently sized aggregations, and consequently, no evidence was found in support of the hypothesis on reduced harassment. The combination of aggregation pheromone possession and a mutualistic relationship with micro‐organisms for Drosophila and other insects is discussed.
Divergent responses of two cereal aphids to previous infestation of their host plant
Authors: Messina Frank J. , Taylor Rodrick , Karren Margaret E.
Published: October 2003

We examined the effects of prior infestation by the Russian wheat aphid [Diuraphis noxia (Mordvilko)] and the bird cherry‐oat aphid [Rhopalosiphum padi (L.)] on the subsequent feeding preferences and performance of each species. Aphid colonies fed and reproduced on wheat seedlings for five days and were then removed. After a period of plant recovery, we estimated aphid population growth and feeding preferences on control and previously infested plants. Previous infestation by D. noxia had no effect on the subsequent population growth of either aphid species. Previous infestation by R. padi reduced its own subsequent growth by 50%, but had little effect on the population growth of D. noxia. When presented leaves from control plants and D. noxia‐infested plants, D. noxia adults preferred to feed on leaves from control plants; R. padi adults showed no preference. Both aphids preferred leaves from control plants to those from R. padi‐infested plants. In free‐flight cages, alates of R. padi settled more often and produced more progeny on control plants than on plants previously infested by R. padi, but their rates of settling and reproduction were unaffected by prior D. noxia infestation. Together, our results suggest specificity in both the plant response to the two aphid species (plant quality for R. padi was lowered by prior R. padi infestation but not by D. noxia infestation) and in each aphid's response to the same modification of the host plant (infestation by R. padi reduced plant quality for itself but not for D. noxia). Effects of prior infestation on the feeding preferences of R. padi were correlated with effects on performance.
Girdling‐induced nutrient accumulation in above ground tissue of peanuts and subsequent feeding by Spissistilus festinus, the three‐cornered alfalfa hopper
Authors: Andersen Peter C. , Brodbeck Brent V. , Herzog Donald C.
Published: October 2003

Changes in nutrient partitioning in stems and leaves of peanut (Arachis hypogaea L.) were examined after girdling of stems by Spissistilus festinus (Say) (Homoptera:Membracidae), the three‐cornered alfalfa hopper. Under field conditions amino acids increased more than 12‐fold in concentration in the 2 cm stem section above the girdle compared to below the girdle or control stems for newly formed girdles (less than 7–11 days). Asparagine and proline were the predominant amino acids, and increased 40‐ and 60‐fold, respectively, above the girdle compared to below the girdle. There was no buildup of nutrient assimilates for the older girdled stems that had callused (and presumably recovered from feeding injury). A time course from 1–11 days was followed under greenhouse conditions, and girdled regions remained enriched in sugars for one day and amino acids for four days after girdle formation. After girdle formation most S. festinus responded to nutrient sinks by feeding within 5 mm above the girdle. This behavior was most pronounced one day after girdle formation, but persisted for seven days after girdle formation. During this period a new girdle was often formed within 10 mm above the original girdle. Under field conditions, stems and leaves derived from stems that had sustained an early or late season girdle generally had a reduced dry weight, total nitrogen content, and total carbon content; however, significant differences did not always occur. Thus, although temporary changes occurred in nutrient partitioning in girdled stems, there appears to be longer term negative growth effects on leaves and stems.
Conditioning of appetitive behavior in the Hymenopteran parasitoid Microplitis croceipes
Authors: Wäckers Felix L. , Bonifay Claire , Lewis W. Joe
Published: October 2003

Work on insect learning has made ample use of conditioned behaviors in single learning tasks. Parasitic wasps are particularly suited to study more complex learning processes, as they alternate between host searching and foraging for sugar sources. We here describe a set of behaviors that unambiguously represents sugar feeding in the Hymenopteran parasitoid Microplitis croceipes (Cresson) (Hymenoptera: Braconidae). Furthermore, we demonstrate that this parasitoid can be conditioned to exhibit these behaviors in response to odor stimuli previously associated with feeding. In conjunction with a previously described ovipositor probing response in this species, our findings constitute the first instance in which multiple conditioned behaviors representing feeding and reproduction have been identified for one insect species. This provides a valuable tool for the study of multiple task learning.
How do herbivorous insects cope with noxious secondary plant compounds in their diet?
Authors: Glendinning John I.
Published: October 2003

Herbivorous insects use a variety of physiological mechanisms to cope with noxious (i.e., unpalatable and/or toxic) compounds in their food plants. Here, I review what is known about this coping process, focusing on one species of caterpillar, the tobacco hornworm (Manduca sexta). Herbivorous insects possess both preingestive (i.e., chemosensory) and postingestive response mechanisms for detecting plant secondary compounds. Stimulation of either class of detection mechanism inhibits feeding rapidly by reducing biting rate and/or bite size. This aversive response is highly adaptive during encounters with secondary plant compounds that are toxic. The insect's dilemma is that many harmless or mildly toxic compounds also activate the aversive response. To overcome this dilemma, herbivorous insects employ at least three mechanisms for selectively deactivating their aversive response to relatively harmless secondary plant compounds: (1) the presence of carbohydrates can mask the unpalatable taste of some secondary plant compounds; (2) prolonged dietary exposure to some unpalatable secondary plant compounds can initiate long‐term adaptation mechanisms in the peripheral and central gustatory system; and (3) dietary exposure to toxic compounds can induce production of P450 detoxication enzymes. Thus, herbivorous insects utilize an integrated suite of physiological mechanisms to detect potentially toxic compounds in foods, and then selectively adapt to those that do not pose a serious threat to their growth and survivorship.
Interspecific competition between the polyembryonic wasp Copidosoma floridanum and the gregarious endoparasitoid Glyptapanteles pallipes
Authors: Utsunomiya Akio , Iwabuchi Kikuo
Published: October 2003

We examined interspecific competition between the egg‐larval polyembryonic parasitoid Copidosoma floridanum (Hymenoptera: Encyrtidae) and the gregarious larval endoparasitoid Glyptapanteles pallipes (Hymenoptera: Braconidae). Approximately 72% of multiparasitized Acanthoplusia agnata (Lepidoptera: Noctuidae) produced C. floridanum adults, 14% produced G. pallipes adults, and 14% died without producing any parasitoids. Development was delayed and the rate of weight gain was reduced in multiparasitized hosts that produced C. floridanum compared with singly‐parasitized hosts. In contrast, only weight was reduced in multiparasitized hosts that produced G. pallipes adults. Compared with single parasitism, the brood size of wasps emerging from multiparasitized hosts was reduced in both species. The percentage of hosts containing precocious larvae of C. floridanum, which are considered to be soldiers, did not increase in response to parasitization by G. pallipes. However, developmental cessation and death of G. pallipes eggs and larvae may be closely related to the number of coexisting precocious larvae.
Information exchange and the robustness of organizational networks
Authors: Dodds Peter Sheridan , Watts Duncan J. , Sabel Charles F.
Published: October 2003

The dynamics of information exchange is an important but understudied aspect of collective communication, coordination, and problem solving in a wide range of distributed systems, both physical (e.g., the Internet) and social (e.g., business firms). In this paper, we introduce a model of organizational networks according to which links are added incrementally to a hierarchical backbone and test the resulting networks under variable conditions of information exchange. Our main result is the identification of a class of multiscale networks that reduce, over a wide range of environments, the likelihood that individual nodes will suffer congestion-related failure and that the network as a whole will disintegrate when failures do occur. We call this dual robustness property of multiscale networks “ultrarobustness.” Furthermore, we find that multiscale networks attain most of their robustness with surprisingly few link additions, suggesting that ultrarobust organizational networks can be generated in an efficient and scalable manner. Our results are directly relevant to the relief of congestion in communication networks and also more broadly to activities, like distributed problem solving, that require individuals to exchange information in an unpredictable manner.
Coupled prediction of protein secondary and tertiary structure
Authors: Meiler Jens , Baker David
Published: October 2003

The strong coupling between secondary and tertiary structure formation in protein folding is neglected in most structure prediction methods. In this work we investigate the extent to which nonlocal interactions in predicted tertiary structures can be used to improve secondary structure prediction. The architecture of a neural network for secondary structure prediction that utilizes multiple sequence alignments was extended to accept low-resolution nonlocal tertiary structure information as an additional input. By using this modified network, together with tertiary structure information from native structures, the Q3-prediction accuracy is increased by 7–10% on average and by up to 35% in individual cases for independent test data. By using tertiary structure information from models generated with therosettade novotertiary structure prediction method, the Q3-prediction accuracy is improved by 4–5% on average for small and medium-sized single-domain proteins. Analysis of proteins with particularly large improvements in secondary structure prediction using tertiary structure information provides insight into the feedback from tertiary to secondary structure.
Avian migration phenology and global climate change
Authors: Cotton Peter A.
Published: October 2003

There is mounting evidence that global climate change has extended growing seasons, changed distribution patterns, and altered the phenology of flowering, breeding, and migration. For migratory birds, the timing of arrival on breeding territories and over-wintering grounds is a key determinant of reproductive success, survivorship, and fitness. But we know little of the factors controlling earlier passage in long-distance migrants. Over the past 30 years in Oxfordshire, U.K., the average arrival and departure dates of 20 migrant bird species have both advanced by 8 days; consequently, the overall residence time in Oxfordshire has remained unchanged. The timing of arrival has advanced in relation to increasing winter temperatures in sub-Saharan Africa, whereas the timing of departure has advanced after elevated summer temperatures in Oxfordshire. This finding demonstrates that migratory phenology is quite likely to be affected by global climate change and links events in tropical winter quarters with those in temperate breeding areas.
Identification of a family of cAMP response element-binding protein coactivators by genome-scale functional analysis in mammalian cells
Authors: Iourgenko Vadim , Zhang Wenjun , Mickanin Craig , Daly Ira , Jiang Can , Hexham Jonathan M. , Orth Anthony P. , Miraglia Loren , Meltzer Jodi , Garza Dan , Chirn Gung-Wei , McWhinnie Elizabeth , Cohen Dalia , Skelton Joanne , Terry Robert , Yu Yang , Bodian Dale , Buxton Frank P. , Zhu Jian , Song Chuanzheng , Labow Mark A.
Published: October 2003

This report describes an unbiased method for systematically determining gene function in mammalian cells. A total of 20,704 predicted human full-length cDNAs were tested for induction of the IL-8 promoter. A number of genes, including those for cytokines, receptors, adapters, kinases, and transcription factors, were identified that induced the IL-8 promoter through known regulatory sites. Proteins that acted through a cooperative interaction between an AP-1 and an unrecognized cAMP response element (CRE)-like site were also identified. A protein, termed transducer of regulated cAMP response element-binding protein (CREB) (TORC1), was identified that activated expression through the variant CRE and consensus CRE sites. TORC1 potently induced known CREB1 target genes, bound CREB1, and activated expression through a potent transcription activation domain. A functionalDrosophilaTORC gene was also identified. Thus, TORCs represent a family of highly conserved CREB coactivators that may control the potency and specificity of CRE-mediated responses.