bluuebunny/crossref_metadata_2025 huggingface dataset:
Nematode specific gravity profiles and applications to flotation extraction and taxonomy
Authors: Carta Lynn , Carta David
Published: July 2002

A technique is described that refines the standard sugar flotation procedure used to isolate nematodes from their surroundings. By centrifuging nematodes in a number of increasing specific gravity solutions and plotting the fraction floating, the cumulative probability distribution of the population’s specific gravity is generated. By assuming normality, the population mean, μ, and standard deviation, σ, are found by a nonlinear least squares procedure. These density parameters along with their error covariance matrix may be used as a taxonomic physical character. A chi-squared test is derived for comparing populations. Mean and standard deviation pairs (μ, σ) were found for the specific gravities of the adult stage of the plant parasites Pratylenchus agilis (1.068, 0.017), P. scribneri (1.073, 0.028), P. penetrans (1.058, 0.008) and the bacterial-feeder Caenorhabditis elegans (1.091, 0.016). La technique exposée affine le procédure standard par flottation au sucre utilisée pour séparer les nématodes de leur milieu. La centrifugation des nématodes dans une série de solutions de densités spécifiques et la mise en diagramme de la valeur de la fraction surnageante permettent de connaître le répartition de la probabilité cumulée de la densité spécifique de la population en cause. La normalité étant supposée, la moyenne de la population, μ, et la déviation standard, σ, sont calculées par la méthode des moindres carrés non linéaires. Ces paramètres relatifs à la densité ainsi que leur matrice de co-variance d’erreur peuvent être utilisés en taxinomie comme caractère physique. Un test chi2 en est dérivé pour comparer les populations entre elles. Des données en paires — moyenne (μ) et écart-type (σ) — ont été définies pour les densités des adultes des espèces phytoparasites Pratylenchus agilis (1,068; 0,017), P. scribneri (1,073; 0,028), P. penetrans (1,058; 0,008), ainsi que pour l’espèce bactérivore Caenorhabditis elegans (1,091; 0,016).
Nematodes from Rajasthan, India. 1. Six new species of Dorylaimida
Authors: Baqri Qaiser , Bohra Padma
Published: July 2002

Six new species of the order Dorylaimida are described from Rajasthan, India: Mesodorylaimus kauli sp. n., 1.00-1.14 mm long, odontostyle 11-13 μm, female tail convex-conoid with elongated dorsally bent tip, male with 40-42 μm long spicules and ten to 11 regularly spaced ventromedian supplements; Mesodorylaimus bhansalii sp. n., 1.07-1.33 mm long, odontostyle 11-14 μm, female tail 5.3-5.4 anal body diam. long, male with 35-37 μm long spicules and 14-15 contiguous ventromedian supplements; Kochinema farodai sp. n., 0.96-1.18 mm long, well set off lip region, amphidial apertures prominent, odontostyle 17-19 μm, guiding ring one lip region diam. (LRD) from anterior end, tail 28-32 μm long, convex-conoid with rounded terminus; Kochinema caudatum sp. n., 0.81-0.95 mm long, well set off lip region, odontostyle 35-38 μm, odontophore 36-38 μm, guiding ring 2.1 LRD from anterior end and convex conoid tail with rounded tip; Tylencholaimus nagauriensis sp. n., 0.64-0.74 mm long, characterised by having perioral region disc-like, odontostyle 8-9 μm, monoprodelphic female reproductive system and anteriorly directed vagina; Tylencholaimus annulatus sp. n., distinct from all the known species of the genus in having coarsely striated inner cuticle giving an appearance like the species of Tylenchida, characterised by L = 0.50-0.59 mm, odontostyle 10-12 μm, odontophore 13-15 μm, amphidelphic female reproductive system and convex-conoid tail with rounded tip.
Optimising the Whitehead and Hemming tray method to extract plant parasitic and other nematodes from two soils under pasture
Authors: Bell Nigel , Watson Richard
Published: July 2002

Three variations of the Whitehead and Hemming tray method for extracting vermiform nematodes from soil samples, and the decant and sieve method, were compared using a silt loam and a clay loam soil under long-term pasture. Comparisons showed that greatest nematode recovery was achieved when 50 g of soil was placed in a tray lined with two-ply paper tissue and extracted for 48 h with 500 ml water. Recovery of the total nematode fauna and of plant parasitic nematodes from the tray extract was significantly better (P ≤ 0.001) after allowing nematodes to sediment in a 1 l straight-sided beaker than in a 15 cm diam. filter funnel. After 48 h extraction on trays, this method recovered 77% of the total numbers of all nematodes (72.5% of the plant parasites) extracted over 144 h with daily collection from the trays. The optimum extraction duration was different for Paratylenchus nanus compared to Pratylenchus sp., apparently related to differences in their mode of parasitism, with root-dwelling stages of Pratylenchus being recovered at longer times. There was a significant treatment × soil interaction for Meloidogyne sp., recovery of which was improved by beaker sedimentation in silt loam but not clay loam soil, compared to funnel sedimentation. A significant treatment × soil interaction was also observed for H. trifolii, the beaker method being better at recovering this nematode in clay loam than silt loam soil, compared to the decant and sieve method.
Effect of time and inoculum density on the reproductive fitness of Pratylenchus coffeae and Radopholus similis populations on carrot disks
Authors: Stoffelen Ruth , Jimenez Maria Isabel , Dierckxsens Christophe , Tam Vu Thi Thanh , Swennen Rony , Waele Dirk De
Published: July 2002

The reproductive fitness of three Pratylenchus coffeae populations (Honduras,
Ghana and Vietnam) and three Radopholus similis populations (Costa Rica,
Cuba and Ghana) on carrot disks was studied as a function of time and
inoculum densities. In the first study, the reproductive fitness of the
isolates was followed during 11 weeks for P. coffeae and during 7 weeks for
R. similis. All the populations increased with time. No distinction could be
found in the maximum growth rate of the Pratylenchus populations. The R.
similis population from Cuba had a higher maximum growth rate than those
from Ghana and Costa Rica. All the Radopholus populations showed a faster
multiplication than P. coffeae. In the second study, the influence of the
inoculum density on the reproductive fitness was determined for the six
populations. The differences in reproduction ratios confirmed the results of
the first study. Effetde la duree et du taux d'inoculum sur la reproduction
de trois populations de Pratylenchus coffeae et de Radopholus similis eleves
sur rondelles de carottes - La reproduction de trois populations de
Pratylenchus coffeae (Honduras, Ghana et Vietnam) et de trois populations de
Radopholus similis (Costa Rica, Cuba et Ghana) a ete etudiee en elevages sur
rondelles de carottes. Dans une premiere etude, la multiplication du P.
coffeae a ete etudiee pendant 11 semaines et celle du R. similis pendant 7
semaines. Toutes les populations se sont accrues avec le temps. Aucune
difference dans la vitesse de croissance maximale n'a ete observee entre les
differentes populations de Pratylenchus. La population de R. similis
provenant de Cuba a montre une vitesse de croissance plus elevee par rapport
aux autres populations. Tous les isolats du R. similis ont montre une
multiplication plus rapide que celle des isolats du P. coffeae. Dans la
deuxieme etude, l'effet du taux d'inoculum sur la reproduction a ete
determine. Les differences dans les taux de reproduction observees ont
confirme les resultats obtenus dans la premiere etude.
AUTONOMOUS CAREER CHANGE AMONG PROFESSIONALS: AN EMPIRICAL PHENOMENOLOGICAL STUDY
Authors: Gomes William , Teixeira Marco
Published: July 2002

Seven informants (4 women and 3 men), aged between 32 and 42, who had experienced at least one career change in their lives were interviewed about the history of their career trajectories. The interviews were analyzed according to the systematic and systemic reflexivity proposed by the phenomenological tradition: description, reduction and interpretation. The findings point to the need for professional guidance practice giving attention not only to professional information but also to a reflection of individual and work-related values. This would help both young people and adults to see their own objectives more clearly and to be capable of formulating their own career plans and following them through.
Experimental constraints on illite crystal morphology
Authors: Bauer A. , Velde B. , Gaupp R.
Published: July 2002

Observations of natural minerals and experimental run products show that I-S (illitesmectite mixed-layer minerals) with a high illite content as well as pure mica-illite crystallites can have a lath shape (aspect ratio >3). This shape is common to the I-S minerals under a variety of conditions of formation. The experiments presented indicate that the occurrence of lath-shaped micaillite is due to a slow growth rate from supersaturated solutions. This lath-shaped crystallite is metastable as the ultimate stable shape is hexagonal. A longer period of crystal growth will replace the mica-illite laths with crystallites of a hexagonal form. Thus the presence of lath-shaped micaillite indicates the existence of a metastable crystal form for this mineral.
Source and grain-size influences upon the clay mineral distribution in the Skagerrak and northern Kattegat
Authors: Bengtsson H. , Stevens R. L.
Published: July 2002

Bottom sediments from 78 sites in the Skagerrak-Kattegat area have been used to determine the semi-quantitative distribution of clay minerals, and to interpret sediment provenance and the transport pathways. The sediment reflects incorporation of four sources, affected both by earlier glacial processes and on-going marine mixing. The southern North Sea, characterized by dioctaheadral illite, kaolinite and smectite, is the dominating source. The central North Sea provides a limited, but significant, source for chlorite. The sediment from the Swedish west coast has an unweathered character, containing trioctaheadral illite, vermiculite, illite-vermiculite mixed-layer minerals and chlorite. The contribution from the southern Kattegat (southern Sweden and Denmark) is dominated by kaolinite and smectite. Correlation between clay content and the contents of smectite, kaolinite and chlorite in the Skagerrak indicate that the clay mineral distribution is influenced by sorting. This grain-size dependency must be considered when interpreting sources.
Local fluctuations in feldspar frameworks
Authors: Hayward Stuart A. , Salje Ekhard K. H. , Chrosch Jutta
Published: July 2002

At any set of thermodynamic conditions a mineral will have some well defined equilibrium crystal structure. However, this structure can be locally disturbed by crystal defects, such as domain walls or solute atoms. This distorted structure will only affect a finite volume within the crystal, but the need to retain continuity within the crystal means that this volume must be non-zero. This means, for example, that the boundary between two domains will include a transition zone from one domain's crystal structure to that of the other domain. Thick twin domain walls can be studied quantitatively, by measuring the intensity of diffuse diffraction between pairs of twin-related Bragg peaks. In alkali feldspar (Or30) at room temperature, these walls are approximately 25 Å thick. Similarly, a single solute atom in a mineral will only affect a small region within a crystal. As a result, chemical mixing will only occur in a substitutional solid solution once there is significant overlap between the strain fields around individual solute atoms. This causes the ‘plateau effect’, where the properties of a phase transition are independent of composition. In alkali feldspar, this plateau extends from albite to 2% Or, which corresponds to a strain field radius of 10 Å.

These phenomena can be modelled using Ginzburg-Landau theory, which predicts that the range of these strain fields will increase as the temperature is raised to Tc. This has been confirmed by measuring the thickness of twin walls as a function of temperature.
Polymorphisms of clotting factors modify the risk for primary intracranial hemorrhage
Authors: Corral Javier , Iniesta Juan Antonio , González-Conejero Rocio , Villalón Marino , Vicente Vicente
Published: July 2002

Intracranial hemorrhage is the third most frequent cause of cerebrovascular disease, but few genetic risk factors have been associated with its development. Recently, it has been reported that some polymorphisms that affect clotting factors increase the risk for thrombosis. However, reports have analyzed the effect of polymorphisms influencing the hemostatic state in bleeding disorders insufficiently. A case-control study was conducted of 201 patients with spontaneous intracranial hemorrhage and 201 control subjects matched for age, race, sex, and selected risk factors (hypertension, smoking, and alcohol consumption). Genomic polymerase chain reaction was used to analyze the prevalence of 4 polymorphisms: factor V Leiden, prothrombin 20210A, factor VII−323 Del/Ins of a decanucleotide, and factor XIII V34L. Subjects with factor V Leiden had decreased risk for spontaneous intracranial hemorrhage (odds ratio, 0.19; 95% confidence interval, 0.03-0.95). The frequency of the prothrombin 20210A/G genotype was also lower among patients than controls (1.5% vs 3%, respectively). Moreover, carriers of the −323 Ins allele of factor VII had a 1.54-fold risk for intracranial hemorrhage (95% CI, 1.03-2.72). Finally, no significant differences were observed in the prevalence of factor XIII V34L polymorphism between patients and controls. Therefore, new genetic factors affecting the risk for spontaneous intracranial hemorrhage were identified. These data, together with the relevance of these polymorphisms in thrombotic diseases, support the idea that a polymorphism may play opposite roles in thrombosis and hemorrhage, suggesting an explanation for the high frequency of these polymorphisms in the general population.
Interleukin-4 variant (BAY 36-1677) selectively induces apoptosis in acute lymphoblastic leukemia cells
Authors: Srivannaboon Kleebsabai , Shanafelt Armen B. , Todisco Elisabetta , Forte Carla P. , Behm Frederick G. , Raimondi Susana C. , Pui Ching-Hon , Campana Dario
Published: July 2002

Interleukin 4 (IL-4) suppresses the growth of acute lymphoblastic leukemia (ALL) cells, but its clinical usefulness is limited by proinflammatory activity due mainly to the interaction of cytokine with endothelial cells and fibroblasts. Stroma-supported cultures of leukemic lymphoblasts were used to test the antileukemic activity of an IL-4 variant, BAY 36-1677, in which the mutations Arg 121 to Glu and Thr 13 to Asp ensure high affinity for IL-4Rα/IL-2Rγ receptors expressed by lymphoid cells, without activation of the IL-4Rα/IL-13Rα receptors mainly expressed by other cells. BAY 36-1677 (25 ng/mL) was cytotoxic in 14 of 16 cases of B-lineage ALL; the median reduction in cell recovery after 7 days of culture was 85% (range, 17%-95%) compared to results of parallel cultures not exposed to the cytokine. Twelve of the 14 sensitive cases had t(9;22) or 11q23 abnormalities; 3 were obtained at relapse. BAY 36-1677 induced apoptosis in leukemic lymphoblasts but did not substantially affect the growth of normal CD34+ cells, thus conferring a growth advantage to normal hematopoietic cells over leukemic lymphoblasts in vitro. BAY 36-1677 had antileukemic activity equal or superior to that produced by native IL-4, but it lacked any effects on the growth of endothelial cells and fibroblasts. The molecular manipulation of IL-4 to abrogate its proinflammatory activity has generated a novel and therapeutically promising cytokine for the treatment of high-risk ALL.
Frequent monitoring of Epstein-Barr virus DNA load in unfractionated whole blood is essential for early detection of posttransplant lymphoproliferative disease in high-risk patients
Authors: Stevens Servi J. C. , Verschuuren Erik A. M. , Pronk Inge , van der Bij Wim , Harmsen Martin C. , The T. Hauw , Meijer Chris J. L. M. , van den Brule Adriaan J. C. , Middeldorp Jaap M.
Published: July 2002

Posttransplant lymphoproliferative disease (PTLD) is a frequent and severe Epstein-Barr virus (EBV)–associated complication in transplantation recipients that is caused by iatrogenic suppression of T-cell function. The diagnostic value of weekly EBV DNA load monitoring was investigated in prospectively collected unfractionated whole blood and serum samples of lung transplantation (LTx) recipients with and without PTLD. In PTLD patients, 78% of tested whole blood samples were above the cut-off value of quantitative competitive polymerase chain reaction (Q-PCR) (greater than 2000 EBV DNA copies per mL blood), with the majority of patients having high viral loads before and at PTLD diagnosis. Especially in a primary EBV-infected patient and in patients with conversion of immunosuppressive treatment, rapid increases in peripheral blood EBV DNA load diagnosed and predicted PTLD. In non-PTLD transplantation recipients, only 3.4% of the whole blood samples was above the cut-off value (P < .0001) despite heavy immune suppression and cytomegalovirus (CMV)-related disease. These findings illustrate the clinical importance of frequent EBV DNA load monitoring in LTx recipients. The increased EBV DNA loads in PTLD patients were restricted to the cellular blood compartment, as parallel serum samples were all below cut-off value, which indicates absence of lytic viral replication. EBV+ cells in PTLD patients have a very short doubling time, which can be as low as 56 hours, thereby creating the need for high screening frequency in high-risk patients. Furthermore, it is shown that EBV and CMV can reactivate independently in LTx recipients and that EBV DNA load monitoring may be useful in discriminating PTLD from rejection.
Rapid mobilization of murine hematopoietic stem cells with enhanced engraftment properties and evaluation of hematopoietic progenitor cell mobilization in rhesus monkeys by a single injection of SB-251353, a specific truncated form of the human CXC chemokine GROβ
Authors: King Andrew G. , Horowitz Dan , Dillon Susan B. , Levin Robert , Farese Ann M. , MacVittie Thomas J. , Pelus Louis M.
Published: July 2002

SB-251353 is an N-terminal truncated form of the human CXC chemokine GROβ. Recombinant SB-251353 was profiled in murine and rhesus monkey peripheral blood stem cell mobilization and transplantation models. SB-251353 rapidly and transiently mobilized hematopoietic stem cells and neutrophils into the peripheral blood after a single subcutaneous injection. Transplantation of equivalent numbers of hematopoietic stem cells mobilized by SB-251353 into lethally irradiated mice resulted in faster neutrophil and platelet recovery than stem cells mobilized by granulocyte colony-stimulating factor (G-CSF). A single injection of SB-251353 in combination with 4 days of G-CSF administration resulted in augmented stem and progenitor cell mobilization 5-fold greater than G-CSF alone. Augmented stem cell mobilization could also be demonstrated in mice when a single injection of SB-251353 was administered with only one-day treatment with G-CSF. In addition, SB-251353, when used as a single agent or in combination with G-CSF, mobilized long-term repopulating stem cells capable of hematopoietic reconstitution of lethally irradiated mice. In rhesus monkeys, a single injection of SB-251353 induced rapid increases in peripheral blood hematopoietic progenitor cells at a 50-fold lower dose than in mice, which indicates a shift in potency. These studies provide evidence that the use of SB-251353 alone or in combination with G-CSF mobilizes hematopoietic stem cells with long-term repopulating ability. In addition, this treatment may (1) reduce the number of apheresis sessions and/or amount of G-CSF required to collect adequate numbers of hematopoietic stem cells for successful peripheral blood cell transplantation and (2) improve hematopoietic recovery after transplantation.
Unrelated marrow transplantation for adult patients with poor-risk acute lymphoblastic leukemia: strong graft-versus-leukemia effect and risk factors determining outcome
Authors: Cornelissen Jan J. , Carston Michael , Kollman Craig , King Roberta , Dekker Adriaan W. , Löwenberg Bob , Anasetti Claudio
Published: July 2002

Between 1988 and 1999, 127 patients with poor-risk acute lymphoblastic leukemia (ALL) received a matched unrelated donor transplant using marrow procured by National Marrow Donor Program (NMDP) collection centers and sent out to 46 transplant centers worldwide. Poor risk was defined by the presence of the translocations t(9;22) (n = 97), or t(4;11) (n = 25), or t(1;19) (n = 5). Sixty-four patients underwent transplantation in first remission (CR1), 16 in CR2 or CR3, and 47 patients had relapsed ALL or primary induction failure (PIF). Overall survival at 2 years from transplant was 40% for patients in CR1, 17% in CR2/3, and 5% in PIF or relapse. Treatment-related mortality (TRM) and relapse mortality, estimated as competing risk factors, were 54% and 6%, respectively, in CR1, 75% and 8% in CR2/3, and 64% and 31% in PIF or relapse. Currently 23 CR1 patients are alive and free of disease with a median follow-up of 24 months (range, 3-97). Multivariable analysis showed that CR1, shorter interval from diagnosis to transplantation, DRB1 match, negative cytomegalovirus (CMV) serology (patient and donor), and presence of the Philadelphia chromosome, t(9;22), were independently associated with better disease-free survival (DFS). Transplantation in CR and presence of t(9;22) were associated with lower risk of relapse. Shorter interval from diagnosis to transplantation, DRB1-match, negative CMV, higher marrow cell dose, and Karnofsky score of 90 or higher were associated with less TRM. These results indicate that, despite a relatively high TRM, the low relapse rate resulted in a 37% ± 13% DFS for CR1 patients, comparing favorably to results obtained with chemotherapy alone and matching results following HLA-identical sibling transplantation.
Erythroid Kruppel-like factor (EKLF) coordinates erythroid cell proliferation and hemoglobinization in cell lines derived from EKLF null mice
Authors: Coghill Elise , Eccleston Sarah , Fox Vanessa , Cerruti Loretta , Brown Clark , Cunningham John , Jane Stephen , Perkins Andrew
Published: July 2002

Erythroid Kruppel-like factor (EKLF) is a transcription factor of the C2H2 zinc-finger class that is essential for definitive erythropoiesis. We generated immortal erythroid cell lines from EKLF−/− fetal liver progenitor cells that harbor a single copy of the entire human β-globin locus and then reintroduced EKLF as a tamoxifen-inducible, EKLF–mutant estrogen receptor (EKLF-ER™) fusion protein. Addition of tamoxifen resulted in enhanced differentiation and hemoglobinization, coupled with reduced proliferation. Human β-globin gene expression increased significantly, whereas γ-globin transcripts remained elevated at levels close to endogenous mouse α-globin transcript levels. We conclude that EKLF plays a role in regulation of the cell cycle and hemoglobinization in addition to its role in β-globin gene expression. The cell lines we used will facilitate structural and functional analyses of EKLF in these processes and provide useful tools for the elucidation of nonglobin EKLF target genes.
Stromal cell–derived factor 1α increases polyploidization of megakaryocytes generated by human hematopoietic progenitor cells
Authors: Guerriero Raffaella , Mattia Gianfranco , Testa Ugo , Chelucci Cristiana , Macioce Giampiero , Casella Ida , Samoggia Paola , Peschle Cesare , Hassan Hamisa Jane
Published: July 2002

The alpha chemokine receptor CXCR4 has been shown to be expressed on human hematopoietic progenitor cells and during the megakaryocytic differentiation pathway. Stromal cell–derived factor 1 (SDF-1) is the ligand for CXCR4. In this study, the role of SDF-1α in megakaryocytopoiesis was investigated. CD34+ progenitors purified from peripheral blood were grown in serum-free liquid suspension culture supplemented with thrombopoietin to obtain a virtually pure megakaryocytic progeny. In this condition, the addition of SDF-1α gives rise to megakaryocytes (MKs) showing an increased DNA content and a rise of lobated nuclei, as compared with untreated cells: at day 5, approximately 20% of the cells already showed the presence of more than one nuclear lobe versus fewer than 5% in the control cells; at day 12, approximately 85% of the cells were of large size and markedly polyploid, whereas approximately 60% of the control cells were polyploid, showed fewer lobes, and were a smaller size. This effect was dose-dependent and did not affect the megakaryocytic proliferation. Experiments with the mitogen-activated protein kinase (MAPK) inhibitor PD98059 suggested a role for MAPK pathway on SDF-1α–induced endomitosis. Furthermore, SDF-1α induced a significant increase in the number of proplatelet-bearing MKs and promoted the migration of megakaryocytic cells. Treatment with SDF-1α caused reduction in CXCR4 abundance on the plasma membrane, seemingly owing to receptor internalization. Furthermore, the presence of SDF-1α did not affect the expression of megakaryocytic markers, indicating that differentiation and polyploidization are independently regulated events.
Notch1 inhibits differentiation of hematopoietic cells by sustaining GATA-2 expression
Authors: Kumano Keiki , Chiba Shigeru , Shimizu Kiyoshi , Yamagata Tetsuya , Hosoya Noriko , Saito Toshiki , Takahashi Tokiharu , Hamada Yoshio , Hirai Hisamaru
Published: July 2002

Notch signaling is involved in cell fate decisions in many systems including hematopoiesis. It has been shown that expression of an activated form of Notch1 (aNotch1) in 32D mouse myeloid progenitor cells inhibits the granulocytic differentiation induced by granulocyte colony-stimulating factor (G-CSF). Results of the current study show that aNotch1, when expressed in F5-5 mouse erythroleukemia cells, also inhibits erythroid differentiation. Comparison of the expression levels of several transcription factors after stimulation for myeloid and erythroid differentiation, in the presence or absence of aNotch1, revealed that aNotch1 did not change its regulation pattern with any of the transcription factors examined, except for GATA-2, despite its inhibitory effect on differentiation. GATA-2 was down-regulated when the parental 32D and F5-5 were induced to differentiate into granulocytic and erythroid lineages, respectively. In these induction procedures, however, the level of GATA-2 expression was sustained when aNotch1 was expressed. To ascertain whether maintenance of GATA-2 is required for the Notch-induced inhibition of differentiation, the dominant-negative form of GATA-3 (DN-GATA), which acted also against GATA-2, or transcription factor PU.1, which was recently shown to be the repressor of GATA-2, was introduced into aNotch1-expressing 32D (32D/aNotch1) cells that do not express GATA family proteins other than GATA2. Both DN-GATA and PU.1 reversed the phenotype of 32D/aNotch1 inducing its differentiation when G-CSF was added. Furthermore, enforced expression of HES-1, which is involved in Notch signaling, delayed differentiation of 32D, and again this phenotype was neutralized by DN-GATA. These results indicate that GATA-2 activity is necessary for the Notch signaling in hematopoietic cells.
Bone morphogenetic protein 4 induces efficient hematopoietic differentiation of rhesus monkey embryonic stem cells in vitro
Authors: Li Fei , Lu Shijiang , Vida Loyda , Thomson James A. , Honig George R.
Published: July 2002

A cell culture system consisting of mouse S17 stromal cells supplemented with cytokines was developed for hematopoietic differentiation of rhesus monkey embryonic stem (ES) cells. The differentiated colonies that formed contained clusters of hematopoietic-like cells, as well as structures similar in appearance to embryonic blood islands. When this culture system was supplemented with bone morphogenetic protein 4 (BMP-4), the numbers of primary hematopoietic clusters increased by an average of 15 fold. The primary hematopoietic clusters containing clonogenic precursors (expandable hematopoietic clusters) increased by 18 fold. Immunofluorescence analysis showed that a substantial percentage of the hematopoietic-like cells were CD34+, with morphologic features of undifferentiated blast cells. Enrichment of the CD34+ cells was associated with enhanced stromal-dependent, cytokine-driven formation of cobblestone colonies on secondary plating. The hematopoietic identity of the precursors was further indicated by their expression of genes associated with hematopoietic differentiation, as well as morphologic assessments that showed erythroid and myeloid lineages among the progeny cells. In addition, reverse transcriptase–polymerase chain reaction analysis of BMP-4–treated rhesus monkey ES cells demonstrated an up-regulation of early-expressed genes responsible for embryonic hematopoiesis and angiogenesis during the first 7 days of culture. These observations suggest that embryonic mesoderm regulatory protein may mimic physiologic signals that are required for the onset of embryonic hematopoiesis and stem cell formation in rhesus monkey ES cells.
Autocrine antiapoptotic stimulation of cultured adult T-cell leukemia cells by overexpression of the chemokine I-309
Authors: Ruckes Tobias , Saul Domenica , Van Snick Jacques , Hermine Olivier , Grassmann Ralph
Published: July 2002

Adult T-cell leukemia (ATL) is an aggressive malignancy of CD4+ T cells caused by the human T-cell leukemia virus type 1 (HTLV-1). The viral leukemogenesis is critically dependent on its oncoprotein Tax because the protein as well as the virus can immortalize primary human lymphocytes to permanent growth. As a transcriptional transactivator, Tax can stimulate the expression of distinct cellular genes. Alterations in the expression levels of unknown growth-relevant genes may contribute to the changed growth properties of Tax-immortalized and leukemic cells. To identify genes that are linked to Tax transformation and ATL leukemogenesis, this study systematically compared the gene expression of cultured cells from patients with acute ATL with that of stimulated peripheral blood T lymphocytes. Several overexpressed RNAs that encode signal transduction functions were identified. These include a dual-specific protein phosphatase (PAC1), an interferon-inducible factor (ISG15), a basic helix-loop-helix transcription factor (DEC-1), and the secreted antiapoptotic chemokine I-309. The ATL cell culture supernatants contained an antiapoptotic activity that could be specifically inhibited by antibodies directed against I-309. Inhibition of I-309 receptor (CCR8) signaling by pertussis toxin increased the apoptosis rate of ATL cell cultures in the presence and absence of external apoptotic stimuli. Both the I-309–specific antiapoptotic activity and the proapoptotic effect of inhibitors of I-309 signaling suggest the existence of an antiapoptotic autocrine loop in ATL cells. Thus, the overexpression of this chemokine may inhibit apoptosis in ATL cells and could substantially contribute to their growth.
Alterations of the X-linked lymphoproliferative disease geneSH2D1A in common variable immunodeficiency syndrome
Authors: Morra Massimo , Silander Olin , Calpe Silvia , Choi Michelle , Oettgen Hans , Myers Laurie , Etzioni Amos , Buckley Rebecca , Terhorst Cox
Published: July 2002

X-linked lymphoproliferative (XLP) disease is a primary immunodeficiency caused by a defect in the SH2D1A gene. At least 3 major manifestations characterize its clinical presentation: fatal infectious mononucleosis (FIM), lymphomas, and immunoglobulin deficiencies. Common variable immunodeficiency (CVID) is a syndrome characterized by immunoglobulin deficiency leading to susceptibility to infection. In some patients with CVID, a defective btk orCD40-L gene has been found, but most often there is no clearly identified etiology. Here, 2 unrelated families in whom male members were affected by CVID were examined for a defect in theXLP gene. In one family previously reported in the literature as having progressive immunoglobulin deficiencies, 3 brothers were examined for recurrent respiratory infections, whereas female family members showed only elevated serum immunoglobulin A levels. A grandson of one of the brothers died of a severeAspergillus infection secondary to progressive immunoglobulin deficiency, FIM, aplastic anemia, and B-cell lymphoma. In the second family, 2 brothers had B lymphocytopenia and immunoglobulin deficiencies. X-linked agammaglobulinemia syndrome was excluded genetically, and they were classified as having CVID. The occurrence of FIM in a male cousin of the brothers led to the XLP diagnosis. Because the SH2D1A gene was found altered in both families, these findings indicate that XLP must be considered when more than one male patient with CVID is encountered in the same family, and SH2D1A must be analyzed in all male patients with CVID. Moreover, these data link defects in the SH2D1A gene to abnormal B-lymphocyte development and to dysgammaglobulinemia in female members of families with XLP disease.
High remission rate in T-cell prolymphocytic leukemia with CAMPATH-1H
Authors: Dearden Claire E. , Matutes Estella , Cazin Bruno , Tjønnfjord Geir E. , Parreira Antonio , Nomdedeu Benet , Leoni Pietro , Clark Fiona J. , Radia Deepti , Rassam Saad M. B. , Roques Tony , Ketterer Nicolas , Brito-Babapulle Vasantha , Dyer Martin J. S. , Catovsky Daniel
Published: July 2002

T-cell prolymphocytic leukemia (T-PLL) is a chemotherapy-resistant malignancy with a median survival of 7.5 months. Preliminary results indicated a high remission induction rate with the human CD52 antibody, CAMPATH-1H. This study reports results in 39 patients with T-PLL treated with CAMPATH-1H between March 1993 and May 2000. All but 2 patients had received prior therapy with a variety of agents, including 30 with pentostatin; none achieved complete remission (CR). CAMPATH-1H (30 mg) was administered intravenously 3 times weekly until maximal response. The overall response rate was 76% with 60% CR and 16% partial remission (PR). These responses were durable with a median disease-free interval of 7 months (range, 4-45 months). Survival was significantly prolonged in patients achieving CR compared to PR or no response (NR), including one patient who survived 54 months. Nine patients remain alive up to 29 months after completing therapy. Seven patients received high-dose therapy with autologous stem cell support, 3 of whom remain alive in CR 5, 7, and 15 months after autograft. Stem cell harvests in these patients were uncontaminated with T-PLL cells as demonstrated by dual-color flow cytometry and polymerase chain reaction. Four patients had allogeneic stem cell transplants, 3 from siblings and 1 from a matched unrelated donor. Two had nonmyeloablative conditioning. Three are alive in CR up to 24 months after allograft. The conclusion is that CAMPATH-1H is an effective therapy in T-PLL, producing remissions in more than two thirds of patients. The use of stem cell transplantation to consolidate responses merits further study.
Effect of a large deletion of the basic domain of mitranscription factor on differentiation of mast cells
Authors: Morii Eiichi , Ogihara Hideki , Oboki Keisuke , Kataoka Tatsuki R. , Maeyama Kazutaka , Fisher David E. , Lamoreux M. Lynn , Kitamura Yukihiko
Published: July 2002

The mi transcription factor (MITF) is a basic-helix-loop-helix-leucine zipper transcription factor that is important for the development of mast cells. Cultured mast cells (CMCs) of mi/mi genotype express abnormal MITF (mi-MITF), but CMCs of tg/tg genotype do not express any MITFs. It was previously reported thatmi/mi CMCs showed more severe abnormalities thantg/tg CMCs, indicating that mi-MITF had inhibitory function. Whereas mi-MITF contains a single amino acid deletion in the basic domain, MITF encoded bymiewallele (ew-MITF) deletes 16 of 21 amino acids of the basic domain. Here the effect of a large deletion of the basic domain was examined. Inmiew/miew CMCs, the expression pattern of genes whose transcription was affected by MITF was comparable to that of tg/tg CMCs rather than to that ofmi/mi CMCs. This suggested that ew-MITF lacked any functions. The part of the basic domain deleted inew-MITF appeared necessary for either transactivation or inhibition of transactivation.
Sustained suppression of hepatitis C virus by interferon and ribavirin in hemophilic patients not responding to interferon monotherapy
Authors: Santagostino Elena , Rumi Maria Grazia , Rivi Monica , Colombo Massimo , Mannucci Pier Mannuccio
Published: July 2002

Thirty-nine hemophiliac patients, negative for human immunodeficiency virus, with chronic hepatitis C who failed to respond to interferon (IFN) at 3 million units (MU) given subcutaneously thrice weekly for at least 3 months were retreated with 5 MU IFN for 6 months followed by 3 MU IFN in combination with daily oral doses of 1 or 1.2 g ribavirin. Thirty-four patients (87%) completed the study. In 4 patients treatment was discontinued because of treatment-related symptoms; 1 patient dropped out. Dosage reduction was required in 10 patients (26%) because of ribavirin-related anemia or IFN-related side effects. By intention-to-treat analysis, 14 (37%) had a sustained virologic response with preference for those infected by genotypes other than type 1 (43% versus 12%) and with high transaminases levels (168 U/L versus 116 U/L). Thus, IFN and ribavirin combination therapy led to a sustained suppression of hepatitis in one third of hemophiliac patients resistant to conventional monotherapy.
Germinal center phenotype and bcl-2 expression combined with the International Prognostic Index improves patient risk stratification in diffuse large B-cell lymphoma
Authors: Barrans Sharon L. , Carter Ian , Owen Roger G. , Davies Faith E. , Patmore Russell D. , Haynes Andrew P. , Morgan Gareth J. , Jack Andrew S.
Published: July 2002

The International Prognostic Index (IPI) identifies poor- and good-risk patients with diffuse large B cell lymphoma (DLBCL); however, the majority of patients have an intermediate IPI, with an uncertain prognosis. To determine whether cellular factors can be combined with the IPI to more accurately predict outcome, we have analyzed 177 presentation nodal DLBCLs for the expression of bcl-2 and a germinal center (GC) phenotype (defined by expression of bcl-6 and CD10). P53 gene band shifts were detected using single-stranded conformational polymorphism polymerase chain reaction analysis of exons 5-9 and were correlated with protein expression. In a Cox regression analysis, IPI (R = 0.22, P < .0001) and bcl-2 (R = 0.14, P = .0001) were independent poor prognostic factors and a GC phenotype predicted a favorable outcome (R = −0.025, P = .02). Neither p53 expression nor band shifts had a significant effect on survival. Using the IPI alone, 8% of patients were identified as high risk. Expression of bcl-2 in the intermediate IPI group identified a further 28% of patients with an overall survival comparable to the high IPI group. In the intermediate IPI, bcl-2− group, the presence of a GC phenotype improved overall survival to levels approaching the IPI low group. Following this analysis only 15% of patients failed to be assigned to a favorable- or poor-risk group. Sequential addition of bcl-2 expression and GC phenotype into the IPI significantly improves risk stratification in DLBCL. For the 36% of high-risk patients with a 2-year overall survival of 19%, alternative treatment strategies should be considered in future trials.
Recurrent involvement of the REL and BCL11Aloci in classical Hodgkin lymphoma
Authors: Martı́n-Subero José I. , Gesk Stefan , Harder Lana , Sonoki Takashi , Tucker Philip W. , Schlegelberger Brigitte , Grote Werner , Novo Francisco J. , Calasanz Marı́a J. , Hansmann Martin L. , Dyer Martin J. S. , Siebert Reiner
Published: July 2002

Comparative genomic hybridization studies have shown gains in chromosome region 2p as the most common imbalance in classical Hodgkin lymphoma (cHL). The minimal region of gain contained 2 candidate oncogenes, REL and BCL11A. This study examined the involvement of REL and BCL11A loci in 44 primary cases of cHL by combined immunophenotyping and interphase cytogenetics (FICTION). A median 2p13 copy number above the tetraploid range was detected in 24 (55%) cases. Adjustment for centromere 2 copy number indicated gains of 2p13 in 11 of 31 cHLs (35%) with 8 (26%) high-level amplifications. One cHL displayed selective amplification of the REL locus not affectingBCL11A; another case studied by FICTION and a cHL with cytogenetic 2p change investigated by fluorescence in situ hybridization showed signal patterns suggesting breakpoints in the region spanned by the REL probe. These data indicate thatREL rather than BCL11A may be the target of the 2p13 alterations in cHL.
Role of erythrocyte phosphatidylserine in sickle red cell–endothelial adhesion
Authors: Setty B. N. Yamaja , Kulkarni Surekha , Stuart Marie J.
Published: July 2002

Phosphatidlyserine (PS) exposure on the erythrocyte surface endows the cell with the propensity of adhering to vascular endothelium. Because individuals with sickle cell disease (SCD) manifest loss of erythrocyte membrane asymmetry with PS exposure, we have assessed the contribution of this marker to the process of sickle erythrocyte–microendothelial adhesion. Assays for plasma-induced adhesion were conducted on unactivated endothelium, in the absence of immobilized ligands, such that PS was compared to the erythrocyte adhesion receptor CD36. Blocking studies with erythrocytes pretreated with annexin V (to cloak PS) or anti-CD36 or both revealed an inhibitory effect on adhesion of 36% ± 10% and 23% ± 8% with blocking of both sites suggestive of an additive effect. We next evaluated 87 blood samples from patients with SCD and grouped them into 4 categories based on adhesion marker (CD36 and PS) levels. Results revealed a striking correlation between erythrocyte PS positivity and adhesion. Analyses of the individual patient data demonstrated a positive correlation between PS and adhesion (R = 0.52,P < .000 001), whereas none was noted between adhesion and CD36 (R = 0.2, P > .07). The effect of PS on adhesion appears to be related to the quantitative differences in erythrocyte markers in SCD, with PS the predominant marker when compared to CD36 both in the total erythrocyte population, and when the adherence-prone erythrocyte, the CD71+ stress reticulocyte, was evaluated. Our study signals the entrance of an important new contributor to the field of sickle erythrocyte–endothelial adhesion. The implications of erythrocyte PS exposure in relation to the vascular pathology of SCD need to be assessed.
High-Throughput Tissue Microarray Analysis Used to Evaluate Biology and Prognostic Significance of the E-Cadherin Pathway in Non–Small-Cell Lung Cancer
Authors: Bremnes R. M. , Veve R. , Gabrielson E. , Hirsch F. R. , Baron A. , Bemis L. , Gemmill R. M. , Drabkin H. A. , Franklin W. A.
Published: July 2002

PURPOSE: E-cadherin (E-cad) and its associated intracellular molecules, catenins, are critical for intercellular epithelial adhesion and are often expressed in non–small-cell lung carcinomas (NSCLCs). We constructed tissue microarrays (TMAs) to investigate the expression of cadherins and catenins and their prognostic significance in NSCLC.

PATIENTS AND METHODS: Tumor tissue samples from 193 patients with stages I to III NSCLC were obtained from the University of Colorado Cancer Center and Johns Hopkins Medical Institutions. Viable tumor was sampled in triplicate for the TMAs, and slides were stained by immunohistochemistry with antibodies against E-cad, N-cadherin, alpha (α)-, beta (β)-, and gamma (γ)-catenin, p120, p27, and adenomatous polyposis coli (APC) gene product. Clinical data were collected by the tumor registries. Patients were followed for a median period of 51 months (range, 18 to 100 months).

RESULTS: Absent or severely reduced membranous expression for E-cad, α-, β-, and γ-catenin, and p120 were observed in 10%, 17%, 8%, 31%, and 61% of the cases, respectively. Tumor cell dedifferentiation correlated with reduced expression for E-cad, β-catenin, γ-catenin, and p120 in squamous cell carcinomas but not in adenocarcinomas. There was an inverse correlation between nodal metastasis and expression of E-cad and γ-catenin. Besides the traditional clinical prognostic variables, E-cad and α-, β-, and γ-catenin expression were of positive prognostic value in univariate survival analyses. In multivariate analysis, E-cad expression was the only independent prognostic factor for survival in addition to age, node status, tumor status, and pathologic surgical margins.

CONCLUSION: Reduced expression of E-cad and catenins is associated with tumor cell dedifferentiation, local invasion, regional metastasis, and reduced survival in NSCLC. E-cad is an independent prognostic factor for NSCLC survival.
An Engineered Recombinant Spider Silk Protein Providing Disulfide‐Locked Control over Self‐Assembly and Fiber Formation
Authors: Sulekha Anamika , Evans Sara , Badichi Akher Farideh , Ghimire Anupama , Reith Melissa A. , Liu Xiang‐Qin , Xu Lingling , Rainey Jan K.
Published: December 2024

Spider silks are renowned for their mechanical properties. The notably tough Argiope trifasciata aciniform silk is spun from a protein predominantly comprising a series of identical 200 residue units (“W units”). In solution, each W unit has a globular 5‐helix domain connected to its neighbors by intrinsically disordered linkers while the fiber contains mixed α‐helical, β‐sheet and disordered structuring. Helix 5 is more dynamic and prone to denaturation than the remainder of the globular domain, implying that it may structurally transform during fiber spinning. Rational cysteine substitutions are introduced at a proximal pair of serines in helix 5 and in helix 1 of the globular domain. Upon disulfide formation, the helix 5 C‐terminal region loses helicity and experiences increased backbone dynamics, while the remainder of the globular structure is effectively unperturbed. Fiber formation by hand‐drawing and wet‐spinning is prevented in the disulfide‐locked state, but readily possible in the reduced (“unlocked”) state. The disulfide‐locked state differs from the unlocked state with much more heterogeneous pre‐fibrillar assembly in spinning dope and through prevention of β‐sheet formation upon cooling following thermal denaturation. This engineered protein thus provides a chemically‐reversible disulfide‐locked state of aciniform silk with modified self‐assembly propensity and fiber formation.