bluuebunny/crossref_metadata_2025 huggingface dataset:
LACK OF WORKER POLICING IN THE CAPE HONEYBEE (APIS MELLIFERA CAPENSIS)
Authors: Moritz R.F.A. , Kryger  , Allsopp M.H.
Published: July 2002

In honeybees (Apis mellifera) laying worker offspring is rare. One mechanism to suppress worker reproduction is through worker policing, i.e. workers remove unfertilised eggs laid by other workers. This behaviour has been shown to be adaptive as soon as the queen performs polyandrous matings. The average relatedness to the queen's drones is higher than to the worker laid offspring. In the Cape honeybee (A. m. capensis) reproductive workers lay fertilised eggs which develop into females. In this case the average worker relatedness to sexual reproductives reared from worker or queen offspring is identical. Worker policing has been predicted by evolutionary theory to be less expressed in A. m. capensis colonies than in other honeybees. We found genetic evidence that worker policing is not common in the Cape honeybee. Laying worker offspring was identified in queen right colonies using microsatellite DNA analysis.
Identification of Heterodera avenae group species by morphometrics and rDNA-RFLPs
Authors: Subbotin Sergei , Waeyenberge Lieven , Molokanova Irina , Moens Maurice
Published: July 2002

Canonical discriminant analysis of four morphometric characters of juveniles and restriction enzymes analysis of ribosomal DNA sequences were used to distinguish Heterodera arenaria, H. aucklandica, H. avenae, H. filipjevi, H. hordecalis, H. iri, H. latipons, H. litoralis, H. schachtii and an undescribed species from grasslands. The results of unweighted pair group cluster analysis showed that H. avenae populations formed three groups and H. filipjevi two groups at the 80% level of similarity. Intraspecific polymorphism was revealed by rDNA-RFLP studies and two types of ITS regions within H. avenae populations can be distinguished. The pattern of restriction bands obtained with BsuRI, PstI and TaqI clearly distinguished populations of H. filipjevi from other species of the H. avenae group. Further enzymes and their combinations distinguished the other species. There are no enzymes which differentiate European populations of H. avenae from H. arenaria. Morphometrics, restriction endonuclease cleavage maps of ITS regions and a dendrogram of putative phylogenetic relations of several cyst-forming nematode species are given. Identification des especes du groupe Heterodera avenae par la morphometrie et les rDNA-RFLP - L'analyse canonique discriminante sur quatre caracteres morphometriques des juveniles et l'analyse des enzymes de restriction de l'ADN ribosomal ont ete utilisees pour identifier Heterodera arenaria, H. aucklandica, H. avenae, H. filipjevi, H. hordecalis, H. iri, H. latipons, H. litoralis, H. schachtii et une nouvelle espece originaire de prairies. Les resultats de l'analyse UPGMA ont montre que les populations d'H. avenae formaient trois groupes et celles d'H. filipjevi deux groupes a un niveau de similarite de 80%. Le polymorphisme intraspecifique a ete revele par des etudes de rDNA-RFLP et deux types de regions de l'ITS peuvent etre mis en evidence dans les populations d'H. avenae. Les modeles de bandes de restriction obtenus avec BsuRI, PstI et TaqI ont identifie clairement les populations d'H. filipjevi des autres especes du groupe H. avenae. D'autres enzymes et leurs combinaisons ont identifie les autres especes. Aucun enzyme n'a differencie les populations europeennes d'H. avenae de H. arenaria. Les caracteres morphometriques, les cartes de clivage des regions des ITS par l'endonuclease de restriction et un dendogramme des relations phylogenetiques supposees sont donnes.
Regional distribution of diagenetic carbonate cement in Palaeocene deepwater sandstones: North Sea
Authors: Stewart R. N. T. , Haszeldine R. S. , Fallick A. E. , Wilkinson M. , Macaulay C. I.
Published: July 2002

Sandstones of the Palaeocene Montrose Group were deposited in a deepwater fan environment, and form a major oil reservoir in the North Sea. Calcite concretions occur commonly within thick-bedded and structureless sandstones. These concretions have been identified by sonic logs and well reports, and were cross-checked with available core data. Regionally, 101 wells have been examined and carbonate concretions form 0.6–7.2% of the core. Concretions are most abundant along the flank of the Fladen Ground Spur, the north Witch Ground Graben (WGG), the east south Viking Graben and East Central Graben (ECG). Concretions of the ECG formed at deep burial, with C from decarboxylation. Geochemical inheritance of Mn and Sr from Cretaceous chalk clasts may occur. Concretion growth may also have been influenced by vertical expulsion of fluids (leak-off) localized above salt tectonics. Isotopic and petrographic evidence indicates that much carbonate C in the WGG was derived from biodegradation of migrating oil in meteoric water at shallow depth. The locations of abundant carbonate with characteristic negative C isotope signatures can be used as shallow exploration guides to leak-off points located above deep overpressured structures.
Sulphur isotope variations in diagenetic pyrite from core plug to sub-millimetre scales
Authors: McConville P. , Boyce A. J. , Fallick A. E. , Harte B. , Scott E. M.
Published: July 2002

Sulphur isotope ratio measurements (δ34S) of diagenetic pyrite are commonly used to identify S sources and mechanisms of sulphide formation in basinal sediments. This study reports such data for a diagenetic pyrite nodule from the Brent Group sandstones of the northern North Sea at three sampling scales: 50 cm (core subsample), 500 μm (laser microprobe) and 50 μm (ion microprobe). Similar δ34S variations are found by the laser and ion microprobe techniques. There is a very wide range in δ34S (<−10% to >+50%) within the nodule and isotopically heavy S (δ34S >+20%) is common at all scales. The nodule δ34S distribution does not fit a Rayleigh fractionation pattern. The laser microprobe sampling at 100–500 μm scales seems to be adequate to characterize S isotope variations in this material.
Clay mineralogy of Galician coastal and oceanic surface sediments: contributions from terrigenous and authigenic sources
Authors: Belzunce-Segarra M. J. , Wilson M. J. , Fraser A. R. , Lachowski E. , Duthie D. M. L.
Published: July 2002

The clay mineralogy of sediments collected from the San Simón inlet, the Ría de Vigo, the Galician Platform, the Galician Margin and the Celtic Sea has been studied using XRD, IR and TEM with a microanalytical attachment. All samples consisted largely of dioctahedral mica and kaolin minerals, in addition to significant amounts of gibbsite, chloritic and smectitic minerals. The clay mineralogy of the sediments is generally consistent with terrigenous inputs from soils and weathered rocks of the Galician granitic hinterland. It is of particular interest that gibbsite, which is not a common constituent of soils of temperate climates, has previously been shown to occur in weathering profiles in this region and may therefore be regarded as an indicator of ‘‘continentality’’, as suggested by Macías Vásquez and co-workers. The smectitic mineral is Fe-rich and also contains significant amounts of K. This mineral is likely to be ultimately of an authigenic origin and may possibly be important as a precursor mineral in a diffuse, non-granular glauconitization process.
Wooldridgeite,
Na2(P2O7)2(H2O)10:
A new mineral from Judkins Quarry, Warwickshire, England
Authors: Hawthorne F. C. , Cooper M. A. , Green D. I. , Starkey R. E. , Roberts A. C. , Grice J. D.
Published: July 2002

Wooldridgeite, ideally Na2(P2O7)2(H2O)10,
orthorhombic, a = 11.938(1),
b = 32.854(2), c =
11.017(1) Å , V = 4321.2(8) Å3,
a:b:c = 0.3634:1:0.3353, space group
Fdd2, Z = 8, is a new mineral from Judkins Quarry,
Nuneaton, Warwickshire, England. Associated minerals are calcite, chalcopyrite,
bornite and baryte. It occurs as equant crystals forming rhombic dipyramids; no
twinning was observed. It is transparent blue-green with a very pale-blue streak,
a vitreous lustre, and does not fluoresce under long- or short-wave ultraviolet
light. Wooldridgeite has a Mohs hardness of 2–3, is brittle with an irregular
fracture, and has no cleavage. The calculated density is 2.279
g/cm3. In transmitted light, wooldridgeite is colourless,
non-pleochroic, and shows no dispersion. It is biaxial negative with α = 1.508(1),
β = 1.511(1), γ = 1.517(1), 2V(meas.) = 76.2(5), 2V(calc.) = 71(10)8, X =
b, Y = c, Z =
a. The strongest five reflections in the X-ray
powder diffraction pattern are [d(Å),
(I), (hkl)]:
8.23(30)(040), 6.52(100)(131), 4.05(40)(260), 3.255(40)(262); 2.924(40)(371).
Electron-microprobe analysis of wooldridgeite gave
P2O5 39.37, CuO 20.24, MgO 0.24, CaO
7.73, Na2O 8.33, K2O 0.17,
H2O(calc.) 24.72, sum 100.80 wt.%; the corresponding unit
formula (based on 24 anions) is
(Na1.96K0.03)Ca1.00(Cu1.85Mg0.04)P4.04O14(H2O)10
where the H2O groups were assigned from knowledge of the
crystal structure; the infrared absorption spectrum also indicates the presence of
H2O in the structure. The mineral is named for James Wooldridge (1923–1995), a
fervent amateur mineral collector who discovered this mineral.
Mn- and F-bearing rasvumite in natrocarbonatite at Oldoinyo Lengai volcano,
Tanzania
Authors: Jago B. C. , Gittins J.
Published: July 2002

Several K-Fe sulphide minerals have been described from natrocarbonatite
lavas erupted from the Tanzanian volcano Oldoinyo Lengai but uncertainty remains
about their exact identity. They do not appear to be any of the established K-Fe
sulphides according to Dawson et al. (1995) and
Mitchell (1997). Here, we describe yet another variant which is a Mn- and
F-bearing variety of rasvumite. It appears to have formed by reaction of Fe
alabandite grains with natrocarbonatite magma and occurs as minute rims on the
alabandite. Its formula is:
(K0.94Na0.06)(Fe1.91Mn0.13Ca0.01Sr0.01)(S2.06F0.24Cl0.04).
Crystal-chemistry of zirconolite and calzirtite from Jacupiranga, São Paulo (Brazil)
Authors: Bellatreccia F. , Della Ventura G. , Caprilli E. , Williams C. T. , Parodi G. C.
Published: July 2002

A specimen of zirconolite, collected from the type locality of the mineral originally described as zirkelite at Jacupiranga, São Paulo, Brazil has been re-examined and its mineral chemistry more completely characterized. All crystals studied are metamict and display very fine lamellar oscillatory zoning (1–3 µm in width) superimposed on a sector zonation. Such zoning, observed in backscattered electron images, is primarily related to differences in the concentration of Th.

In comparison with other reported zirconolite samples from a variety of geological occurrences, Jacupiranga zirconolite has higher Ca, Th, (Nb + Ta) and lower Ti andREE, which is consistent with its occurrence in carbonatitic rocks. The compositional variation with respect to an ideal zirconolite is described by two main coupled substitutions:

Calzirtite, Ca2Zr5Ti2O16, although intergrown with zirconolite and with identical major components, shows much less compositional variability with only minor amounts of Nb and Ta substituting for Ti. Unlike zirconolite, theREEand actinide elements are not easily accommodated in the calzirtite structure.
JAB/SOCS1/SSI-1 is an interleukin-2–induced inhibitor of IL-2 signaling
Authors: Sporri Bernhard , Kovanen Panu E. , Sasaki Atsuo , Yoshimura Akihiko , Leonard Warren J.
Published: July 2002

JAB/suppressor of cytokine signaling 1 (SOCS1) STAT-induced STAT inhibitor–1 (SSI-1) (JAB/SOCS1/SSI-1) is an SH2-domain–containing protein that is induced by and negatively regulates signaling by a number of cytokines including interleukin-4 (IL-4), IL-6, interferon (IFN)-γ, prolactin, growth hormone, and erythropoietin. The role of JAB/SOCS1/SSI-1 in IL-2 signaling has been analyzed. JAB/SOCS1/SSI-1 is strongly induced by IL-2 in peripheral blood T cells, and JAB/SOCS1/SSI-1 overexpression strongly inhibits IL-2–induced signal transducer and activator of transcription–5 (Stat5) phosphorylation and transcriptional activity. In cotransfection experiments, JAB/SOCS1/SSI-1 associates with both Jak1 and Jak3; however, JAB/SOCS1/SSI-1 had a greater effect on Jak1 tyrosine phosphorylation and kinase activity. JAB/SOCS1/SSI-1 also interacts with IL-2Rβ, and this interaction requires the A region (residues 313-382) of IL-2Rβ. However, this interaction was not essential for the inhibitory action of JAB. Thus, JAB/SOCS1/SSI-1 is an IL-2–induced inhibitor of IL-2 signaling that functions by inhibiting Jak kinase activity. This suggests an important role for JAB/SOCS1/SSI-1 in regulating T-cell responses.
Expression of interferon consensus sequence binding protein induces potent immunity against BCR/ABL-induced leukemia
Authors: Deng Ming , Daley George Q.
Published: July 2002

Mice deficient in the interferon consensus sequence binding protein (ICSBP) develop a disease resembling chronic myeloid leukemia (CML), which in humans is caused by the BCR/ABL oncoprotein. Interferon-α (IFN-α) induces ICSBP expression and is an effective therapy for CML. This study examined whether enforced expression of ICSBP might antagonize BCR/ABL-induced leukemia; results demonstrated that ICSBP-modified cells generated a protective CD8+ cytotoxic T-cell response against BCR/ABL-transformed BaF3 cells in a murine leukemia model. ICSBP expression represents a novel means of stimulating a host immune response to BCR/ABL+ leukemia cells and a potential strategy for immunotherapy of CML.
Molecular characterization and expression of a novel human leukocyte cell-surface marker homologous to mouse Ly-9
Authors: de la Fuente Miguel Angel , Tovar Victoria , Villamor Neus , Zapater Nuria , Pizcueta Pilar , Campo Elias , Bosch Jaime , Engel Pablo
Published: July 2002

Ly-9 is a mouse cell-surface glycoprotein that is selectively expressed on thymocytes and on mature T and B lymphocytes. Ly-9 belongs to the CD2 subset of the immunoglobulin superfamily, an emerging family of cell signaling receptors. Recently, a partial human Ly-9 complementary DNA (cDNA) sequence has been described. Full-length cDNA clones were isolated that included the initiation codon, the sequence encoding the full signal peptide, and 14 amino acids more in the cytoplasmic domain than in the previously reported clone. The predicted extracellular domain of human Ly-9 contains 4 immunoglobulinlike domains, similar to those in mouse Ly-9. Northern blot analysis revealed that the human Ly-9 messenger RNA (2.6 kb) is expressed predominantly in lymph node, spleen, thymus, and peripheral blood leukocytes. Four monoclonal antibodies (mAbs) were raised against human Ly-9 by immunizing mice with the pre-B-cell line 300.19 stably transfected with human Ly-9 full-length cDNA. These mAbs strongly stained the surfaces of cells transfected with human Ly-9 cDNA but not of untransfected cells. Human Ly-9 expression was restricted to T and B lymphocytes and thymocytes, with the highest levels of expression on CD4+CD8− and CD4−CD8+ thymocytes. Monocytes, granulocytes, platelets, and red blood cells were uniformly negative for Ly-9. These mAbs immunoprecipitated major polypeptides of 120 kd from the transfected cells and 120 kd and 100 kd from B-cell line Daudi, probably because of the cell-surface–expressed isoforms. These data demonstrate that human Ly-9 is a new marker for the study of normal and malignant leukocytes.
Anti-CD20 monoclonal antibody for the treatment of severe, immune-mediated, pure red cell aplasia and hemolytic anemia
Authors: Zecca Marco , De Stefano Piero , Nobili Bruno , Locatelli Franco
Published: July 2002

Immune-mediated, acquired pure red cell aplasia (PRCA) is a rare disorder frequently associated with other autoimmune phenomena. Conventional immunosuppressive treatment is often unsatisfactory. Rituximab is a monoclonal antibody against the CD20 antigen, highly effective for in vivo B-cell depletion. An 18-month-old girl with both severe PRCA and autoimmune hemolytic anemia, refractory to immunosuppressive treatment, received 2 doses of rituximab, 375 mg/m2 per week. The drug was well tolerated. After anti-CD20 therapy, substitutive treatment with intravenous immunoglobulin was started. The treatment resulted in marked depletion of B cells; a striking rise in reticulocyte count ensued, with increasing hemoglobin levels, finally leading to transfusion independence. The child is now 5 months off-therapy, with normal hemoglobin and reticulocyte levels. This case suggests a role of anti-CD20 monoclonal antibody for treatment of patients with antibody-mediated hematologic disorders.
CD34 expression on long-term repopulating hematopoietic stem cells changes during developmental stages
Authors: Matsuoka Sahoko , Ebihara Yasuhiro , Xu Ming-jiang , Ishii Takefumi , Sugiyama Daisuke , Yoshino Hiroshi , Ueda Takahiro , Manabe Atsushi , Tanaka Ryuhei , Ikeda Yasuo , Nakahata Tatsutoshi , Tsuji Kohichiro
Published: July 2002

The CD34 antigen serves as an important marker for primitive hematopoietic cells in therapeutic transplantation of hematopoietic stem cells (HSC) and gene therapy, but it has remained an open question as to whether or not most HSC express CD34. Using a competitive long-term reconstitution assay, the results of this study confirm developmental changes in CD34 expression on murine HSC. In fetuses and neonates, CD34 was expressed on Lin−c-Kit+ long-term repopulating HSC of bone marrow (BM), liver, and spleen. However, CD34 expression on HSC decreased with aging, and in mice older than 10 weeks, HSC were most enriched in the Lin−c-Kit+CD34− marrow cell fraction. A second transplantation was performed from primary recipients who were transplanted with neonatal Lin−c-Kit+ CD34high HSC marrow. Although donor-type HSC resided in CD34-expressing cell fraction in BM cells of the first recipients 4 weeks after the first transplantation, the stem cell activity had shifted to Lin−c-Kit+CD34− cells after 16 weeks, indicating that adult Lin−c-Kit+CD34− HSC are the progeny of neonatal CD34-expresssing HSC. Assays for colony-forming cells showed that hematopoietic progenitor cells, unlike HSC, continue to express CD34 throughout murine development. The present findings are important because the clinical application of HSC can be extended, in particular as related to CD34-enriched HSC and umbilical cord blood HSC.
Nucleotide receptors: an emerging family of regulatory molecules in blood cells
Authors: Di Virgilio Francesco , Chiozzi Paola , Ferrari Davide , Falzoni Simonetta , Sanz Juana M. , Morelli Anna , Torboli Maurizia , Bolognesi Giorgio , Baricordi O. Roberto
Published: July 2002

Nucleotides are emerging as an ubiquitous family of extracellular signaling molecules. It has been known for many years that adenosine diphosphate is a potent platelet aggregating factor, but it is now clear that virtually every circulating cell is responsive to nucleotides. Effects as different as proliferation or differentiation, chemotaxis, release of cytokines or lysosomal constituents, and generation of reactive oxygen or nitrogen species are elicited upon stimulation of blood cells with extracellular adenosine triphosphate (ATP). These effects are mediated through a specific class of plasma membrane receptors called purinergic P2 receptors that, according to the molecular structure, are further subdivided into 2 subfamilies: P2Y and P2X. ATP and possibly other nucleotides are released from damaged cells or secreted via nonlytic mechanisms. Thus, during inflammation or vascular damage, nucleotides may provide an important mechanism involved in the activation of leukocytes and platelets. However, the cell physiology of these receptors is still at its dawn, and the precise function of the multiple P2X and P2Y receptor subtypes remains to be understood.
Aberrant fibrin formation and cross-linking of fibrinogen Nieuwegein, a variant with a shortened Aα-chain, alters endothelial capillary tube formation
Authors: Collen Annemie , Maas Annemarie , Kooistra Teake , Lupu Florea , Grimbergen Jos , Haas Fred J. L. M. , Biesma Douwe H. , Koolwijk Pieter , Koopman Jaap , van Hinsbergh Victor W. M.
Published: July 2002

A congenital dysfibrinogenemia, fibrinogenNieuwegein, was discovered in a young man without any thromboembolic complications or bleeding. A homozygous insertion of a single nucleotide (C) in codon Aα 453 (Pro) introduced a stop codon at position 454, which resulted in the deletion of the carboxyl-terminal segment Aα 454-610. The ensuing unpaired cysteine at Aα 442 generated fibrinogen-albumin complexes of different molecular weights. The molecular abnormalities of fibrinogenNieuwegein led to a delayed clotting and a fibrin network with a low turbidity. Electron microscopy confirmed that thin fibrin bundles were organized in a fine network. The use of fibrinogenNieuwegein-derived fibrin (fibrinNieuwegein) in an in vitro angiogenesis model resulted in a strong reduction of tube formation. The ingrowth of human microvascular endothelial cells (hMVEC) was independent of αvβ3, indicating that the reduced ingrowth is not due to the absence of the RGD-adhesion site at position Aα 572-574. Rather, the altered structure of fibrinNieuwegeinis the cause, since partial normalization of the fibrin network by lowering the pH during polymerization resulted in an increased tube formation. Whereas factor XIIIa further decreased the ingrowth of hMVEC in fibrinNieuwegein, tissue transglutaminase (TG), which is released in areas of vessel injury, did not. This is in line with the absence of the cross-linking site for TG in the α-chains of fibrinogenNieuwegein. In conclusion, this newly discovered congenital dysfibrinogenemia has a delayed clotting time and leads to the formation of an altered fibrin structure, which could not be cross-linked by TG and which is less supportive for ingrowth of endothelial cells.
Existence of escape mutant in HTLV-I tax during the development of adult T-cell leukemia
Authors: Furukawa Yoshitaka , Kubota Ryuji , Tara Mitsutoshi , Izumo Shuji , Osame Mitsuhiro
Published: July 2002

Although Tax protein is the main target of cytotoxic T lymphocyte (CTL) on human T-cell lymphotropic virus type I (HTLV-I)–infected cells, and Tax peptide 11 through 19 binding to HLA-A*02 has been shown to elicit a strong CTL response, there are patients with adult T-cell leukemia (ATL) bearing HLA-A*02. To explore whether there is genetic variation in HTLV-I tax that can escape CTL recognition during the development of ATL, the HTLV-I tax gene was sequenced in 55 patients with ATL, 61 patients with HTLV-I–associated myelopathy/tropical spastic paraparesis (HAM/TSP), and 62 healthy carriers, and it was correlated with the presence of HLA-A*02. First, a premature stop codon in the 5′ half of the tax gene that looses transactivation activity on the viral enhancer was observed in 3 patients with acute and 1 patient with chronic ATL. This stop codon was revealed to emerge after the viral transmission to the patient from sequence analysis in family members with ATL. Second, amino acid change in Tax peptide 11-19 was observed in 3 patients with ATL. CTL assays demonstrated that this altered Tax 11-19 peptide, observed in ATL patients with HLA-A*02, was not recognized by Tax 11-19–specific CTL. Two patients with ATL had large deletions in tax by sequencing, and 5 patients with ATL had deletions in HTLV-I by Southern blotting. These findings suggest that at some stage of ATL development, HTLV-I–infected cells that can escape the host immune system are selected and have a chance to accumulate genetic alterations for further malignant transformation, leading to acute ATL.
Unique effects of zinc protoporphyrin on HO-1 induction and apoptosis
Authors: Yang Guang , Nguyen Xuandai , Ou Judy , Rekulapelli Prasad , Stevenson David K. , Dennery Phyllis A.
Published: July 2002

Zinc protoporphyrin (ZnPP), a naturally occurring molecule, is increased in iron deficiency and lead intoxication. ZnPP can also induce heme oxygenase (HO-1), the enzyme it competitively inhibits. In cultured cells (HA-1), ZnPP was the strongest HO-1 inducer of any metalloporphyrin (MP) tested. This was not due to increased oxidative stress, enhanced binding at metal response element, nor increased binding at activator protein-1 (AP-1) or SP-1 sites on HO-1. Only ZnPP, however, increased binding of nuclear proteins to early growth response-1 (Egr-1) protein consensus sequence. Pretreatment of HA-1 with cycloheximide inhibited ZnPP-induced HO-1 messenger RNA (mRNA) by 55%. Incubation with antisense Egr-1 oligomers decreased ZnPP-induced HO-1 expression by 47%. Furthermore, the level of HO-1 mRNA induction by ZnPP was 2-fold less in Egr-1–deficient fibroblasts than in wild-type cells. Because no Egr-1 binding site was previously identified on the HO-1 promoter, HA-1 cells were transfected with HO-1 CAT constructs containing segments of a 12.5-kb enhancer region of HO-1. A 196-bp fragment (RH) located approximately 9.5 kb upstream of the transcription start site mediated HO-1 induction by ZnPP alone. DNase I footprinting analysis further revealed that nuclear proteins bound to a 50-bp sequence in the RH. Within this sequence, a novel 9-bp region with 78% homology to the Egr-1 consensus sequence was identified further suggesting that Egr-1 partially mediates HO-1 induction by ZnPP. Lastly, increased apoptosis and nuclear localization were only seen with ZnPP, suggesting that increased ZnPP in disease states may serve as a cellular signaling mechanism.
Sperm protein 17 is a novel cancer-testis antigen in multiple myeloma
Authors: Lim Seah H. , Wang Zhiqing , Chiriva-Internati Maurizio , Xue Yuying
Published: July 2002

Various studies have demonstrated the aberrant expression of normal testicular proteins in neoplastic cells. These proteins collectively form the new class of tumor antigens called cancer-testis (CT) antigens. Their selective normal tissue expression makes them ideal antigens for immune targeting of the malignant disease. In this study, the expression of a spermatozoa protein, Sp17, in multiple myeloma was investigated. It was found that Sp17 is detectable in tumor cells from 12 of 47 (26%) myeloma patients. Reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis detected Sp17 transcripts and proteins, respectively. Northern blot analysis and RT-PCR demonstrated that Sp17 transcripts were detected only in normal testis, supporting its tissue specificity. Since a high proportion of normal individuals develop antibodies against Sp17 following vasectomy, Sp17 is likely to be a highly immunogenic protein in vivo. Sp17 is therefore a novel member of the CT antigen family and should be an ideal target for immunotherapy of multiple myeloma.
Time course of increasing numbers of mutations in the granulocyte colony-stimulating factor receptor gene in a patient with congenital neutropenia who developed leukemia
Authors: Tschan Christoph A. , Pilz Christina , Zeidler Cornelia , Welte Karl , Germeshausen Manuela
Published: July 2002

Point mutations in the granulocyte colony-stimulating factor receptor (G-CSFR) gene have been linked to the development of secondary leukemia in patients with congenital neutropenia (CN). This report presents data on a now 18-year-old patient with CN who has received G-CSF treatment since 1989 and who developed acute myeloid leukemia (AML) in 1998. To evaluate whether there is an association between the occurrence of point mutations of the G-CSFR gene and development of secondary AML, DNA/messenger RNA of neutrophils and mononuclear cells from this patient were analyzed at different time points by polymerase chain reaction and subsequent cloning by DNA sequencing of representative numbers of individual clones. Findings suggest an increasing instability of the G-CSFR gene in time as judged by increasing numbers of mutations proposed to be one important step in the development of AML in this patient.
Prothrombin protects factor Xa in the prothrombinase complex from inhibition by the heparin-antithrombin complex
Authors: Rezaie Alireza R.
Published: July 2002

Heparin is a commonly used anticoagulant drug. It functions primarily by accelerating the antithrombin inhibition of coagulation proteinases, among which factor Xa and thrombin are believed to be the most important targets. There are conflicting results as to whether anticoagulant heparins can catalyze the antithrombin inhibition of factor Xa in the prothrombinase complex (factor Va, negatively charged membrane surfaces, and calcium ion), which is the physiologically relevant form of the proteinase responsible for the activation of prothrombin to thrombin during the blood coagulation process. In this study, a novel assay system was developed to compare the catalytic effect of different molecular-weight heparins in the antithrombin inhibition of factor Xa, either in free form or assembled into the prothrombinase complex during the process of prothrombin activation. This assay takes advantage of the unique property of a recombinant mutant antithrombin, which, similar to the wild-type antithrombin, rapidly inhibits factor Xa, but not thrombin, in the presence of heparin. A direct prothrombinase inhibition assay, monitoring thrombin generation under near physiological concentrations of prothrombin and antithrombin in the presence of therapeutic doses of low- and high-molecular-weight heparins, indicates that factor Xa in the prothrombinase complex is protected from inhibition by antithrombin more than 1000 times, independent of the molecular size of heparin.
Novel vitamin D3 analog, 21-(3-methyl-3-hydroxy-butyl)-19-nor D3, that modulates cell growth, differentiation, apoptosis, cell cycle, and induction of PTEN in leukemic cells
Authors: Hisatake Jun-ichi , O'Kelly James , Uskokovic Milan R. , Tomoyasu Shigeru , Koeffler H. Phillip
Published: July 2002

The active form of vitamin D3, 1,25(OH)2D3, inhibits proliferation and induces differentiation of a variety of malignant cells. A new class of vitamin D3 analogs, having 2 identical side chains attached to carbon-20, was synthesized and the anticancer effects evaluated. Four analogs were evaluated for their ability to inhibit growth of myeloid leukemia (NB4, HL-60), breast (MCF-7), and prostate (LNCaP) cancer cells. All 4 analogs inhibited growth in a dose-dependent manner. Most effective was 21-(3-methyl-3-hydroxy-butyl)-19-nor D3(Gemini-19-nor), which has 2 side chains and removal of the C-19. Gemini-19-nor was approximately 40 625-, 70-, 23-, and 380-fold more potent than 1,25(OH)2D3 in inhibiting 50% clonal growth (ED50) of NB4, HL-60, MCF-7, and LNCaP cells, respectively. Gemini-19-nor (10−8 M) strongly induced expression of CD11b and CD14 on HL-60 cells (90%); in contrast, 1,25(OH)2D3 (10−8 M) stimulated only 50% expression. Annexin V assay showed that Gemini-19-nor and 1,25(OH)2D3 induced apoptosis in a dose-dependent fashion. Gemini-19-nor (10−8 M, 4 days) caused apoptosis in approximately 20% of cells, whereas 1,25(OH)2D3 at the same concentration did not induce apoptosis. Gemini-19-nor increased in HL-60 both the proportion of cells in the G1/G0 phase and expression level of p27kip1. Moreover, Gemini-19-nor stimulated expression of the potential tumor suppressor, PTEN. Furthermore, other inducers of differentiation, all-trans-retinoic acid and 12-O-tetradecanoylphorbol 13-acetate, increased PTEN expression in HL-60. In summary, Gemini-19-nor strongly inhibited clonal proliferation in various types of cancer cells, especially NB4 cells, suggesting that further studies to explore its anticancer potential are warranted. In addition, PTEN expression appears to parallel terminal differentiation of myeloid cells.
The corepressor CtBP interacts with Evi-1 to repress transforming growth factor β signaling
Authors: Izutsu Koji , Kurokawa Mineo , Imai Yoichi , Maki Kazuhiro , Mitani Kinuko , Hirai Hisamaru
Published: July 2002

Evi-1 is a zinc finger nuclear protein whose inappropriate expression leads to leukemic transformation of hematopoietic cells in mice and humans. This was previously shown to block the antiproliferative effect of transforming growth factor β (TGF-β). Evi-1 represses TGF-β signaling by direct interaction with Smad3 through its first zinc finger motif. Here, it is demonstrated that Evi-1 represses Smad-induced transcription by recruiting C-terminal binding protein (CtBP) as a corepressor. Evi-1 associates with CtBP1 through one of the consensus binding motifs, and this association is required for efficient inhibition of TGF-β signaling. A specific inhibitor for histone deacetylase (HDAc) alleviates Evi-1–mediated repression of TGF-β signaling, suggesting that HDAc is involved in the transcriptional repression by Evi-1. This identifies a novel function of Evi-1 as a member of corepressor complexes and suggests that aberrant recruitment of corepressors is one of the mechanisms for Evi-1–induced leukemogenesis.
Activation of apoptosis pathways in peripheral blood lymphocytes by in vivo chemotherapy
Authors: Stahnke Karsten , Fulda Simone , Friesen Claudia , Strauß Gudrun , Debatin Klaus-Michael
Published: July 2002

In addition to myelosuppression, anticancer drugs cause rapid and persistent depletion of lymphocytes, possibly by direct apoptosis induction in mature T and B cells. Induction of apoptosis regulators was analyzed in peripheral blood lymphocytes from pediatric patients undergoing first-cycle chemotherapy for solid tumors. In vivo chemotherapy induced a significant increase in lymphocyte apoptosis ex vivo. The activation of initiator caspase-8 and effector caspase-3 and the cleavage of caspase substrates was detected 12 to 48 hours after the onset of therapy. Caspase inhibition by Z-VAD-fmk did not reduce ex vivo lymphocyte apoptosis in all patients, indicating the additional involvement of caspase-independent cell death. No evidence for the involvement of activation-induced cell death was found in the acute phase of lymphocyte depletion as analyzed by activation marker expression and sensitivity for CD95 signaling. Lymphocyte apoptosis in vivo appeared to be predominantly mediated by the mitochondrial pathway because a marked decrease of mitochondrial membrane potential (ΔΨM) was detected after 24 to 72 hours of treatment, preceded by the increased expression of Bax. Interestingly, despite the use of DNA-damaging agents, p53 remained completely undetectable throughout treatment. In contrast, in vitro treatment with cytarabine and etoposide induced p53 protein, CD95 receptor expression, CD95 sensitivity, and CD95 receptor-ligand interaction in stimulated cycling lymphocytes, but no such induction was seen in resting cells. These data suggest that chemotherapy-induced lymphocyte depletion involves distinct mechanisms of apoptosis induction, such as direct mitochondrial and caspase-dependent pathways in resting cells and p53-dependent pathways in cycling lymphocytes.
Gene transfer into murine hematopoietic stem cells with helper-free foamy virus vectors
Authors: Vassilopoulos George , Trobridge Grant , Josephson Neil C. , Russell David W.
Published: July 2002

Gene transfer into hematopoietic stem cells (HSCs) is an ideal treatment strategy for many genetic and hematologic diseases. However, progress has been limited by the low HSC transduction rates obtained with retroviral vectors based on murine leukemia viruses. This study examined the potential of vectors derived from the nonpathogenic human foamy virus (HFV) to transduce human CD34+ cells and murine HSCs. More than 80% of human hematopoietic progenitors present in CD34+ cell preparations derived from cord blood were transduced by a single overnight exposure to HFV vector stocks. Mice that received transduced bone marrow cells expressed the vector-encoded transgene long term in all major hematopoietic cell lineages and in over 50% of cells in some animals. Secondary bone marrow transplants and integration site analysis confirmed that gene transfer occurred at the stem cell level. Transgene silencing was not observed. Thus vectors based on foamy viruses represent a promising approach for HSC gene therapy.
STAT3 is constitutively activated in Hodgkin cell lines
Authors: Kube Dieter , Holtick Udo , Vockerodt Martina , Ahmadi Tahamtan , Haier Birgit , Behrmann Iris , Heinrich Peter C. , Diehl Volker , Tesch Hans
Published: July 2002

Hodgkin disease (HD) represents a malignant lymphoma in which the putative malignant Hodgkin and Reed-Sternberg cells are rare and surrounded by abundant reactive nonmalignant cells. It has been suggested that cytokines such as interleukin-6 (IL-6) are involved in the pathogenesis of the disease. The expression of the IL-6 receptor (IL-6R) complex and its link to the activation of signal transducers and activators of transcription (STAT) molecules in HD cell lines was investigated. Gel retardation and Western blot analyses revealed a high level of constitutively activated STAT3 in 5 of 7 HD cell lines, which could not be detected in Burkitt lymphoma cell lines. Different levels of IL-6R protein were measured in various HD cell lines: L428 and Dev cells were characterized by very low levels of gp80 and gp130, on KMH2 cells only gp130 but no gp80 was detected, whereas L540, L591, HDLM2, and L1236 were positive for both gp80 and gp130, suggesting a possible autocrine stimulation of STAT3. However, a further increase in STAT3 activation on IL-6 or IL-6/soluble IL-6R stimulation was not observed. Neutralizing monoclonal antibodies against IL-6, gp80, gp130, or both receptor subunits did not affect the proliferation or the constitutive activation of STAT molecules in HD cell lines. However, the tyrosine kinase inhibitor AG490 blocked the constitutive activation of STAT3 and inhibited spontaneous growth of HD tumor cells. The evidence suggests abnormal STAT signaling and growth regulation in Hodgkin cell lines.
A leukemic stem cell with intrinsic drug efflux capacity in acute myeloid leukemia
Authors: Wulf Gerald G. , Wang Rui-Yu , Kuehnle Ingrid , Weidner Douglas , Marini Frank , Brenner Malcolm K. , Andreeff Michael , Goodell Margaret A.
Published: July 2002

The hematopoietic stem cell underlying acute myeloid leukemia (AML) is controversial. Flow cytometry and the DNA-binding dye Hoechst 33342 were previously used to identify a distinct subset of murine hematopoietic stem cells, termed the side population (SP), which rapidly expels Hoechst dye and can reconstitute the bone marrow of lethally irradiated mice. Here, the prevalence and pathogenic role of SP cells in human AML were investigated. Such cells were found in the bone marrow of more than 80% of 61 patients and had a predominant CD34low/− immunophenotype. Importantly, they carried cytogenetic markers of AML in all 11 cases of active disease examined and in 2 out of 5 cases in complete hematological remission. Comparison of daunorubicin and mitoxantrone fluorescence emission profiles revealed significantly higher drug efflux from leukemic SP cells than from non-SP cells. Three of 28 SP cell transplants generated overt AML-like disease in nonobese diabetic–severe combined immunodeficient mice. Low but persistent numbers of leukemic SP cells were detected by molecular and immunological assays in half of the remaining mice. Taken together, these findings indicate that SP cells are frequently involved in human AML and may be a target for leukemic transformation. They also suggest a mechanism by which SP cells could escape the effects of cytostatic drugs and might eventually contribute to leukemia relapse.
Role for lipid rafts in regulating interleukin-2 receptor signaling
Authors: Marmor Mina D. , Julius Michael
Published: July 2002

Lipid rafts are plasma membrane microdomains characterized by a unique lipid environment enriched in gangliosides and cholesterol, leading to their insolubility in nonionic detergents. Many receptors are constitutively or inducibly localized in lipid rafts, which have been shown to function as platforms coordinating the induction of signaling pathways. In this report, the first evidence is provided for a role of these lipid microdomains in regulating interleukin-2 receptor (IL-2R) signaling. It is demonstrated that antibody- or ligand-mediated immobilization of components of lipid rafts, glycosyl-phosphatidyl-inositol–anchored proteins, and the GM1 ganglioside, respectively, inhibit IL-2–induced proliferation in T cells. IL-2Rα is shown to be constitutively enriched in rafts and further enriched in the presence of immobilized anti–Thy-1. In contrast, IL-2Rβ and IL-2Rγ, as well as JAK1 and JAK3, are found in soluble membrane fractions, and their localization is not altered by anti–Thy-1. IL-2–mediated heterotrimerization of IL-2R chains is shown to occur within soluble membrane fractions, exclusively, as is the activation of JAK1 and JAK3. As predicted by these results, the disruption of lipid raft integrity did not impair IL-2–induced signaling. Thus, the sequestration of IL-2Rα within lipid microdomains restricts its intermolecular interactions and regulates IL-2R signaling through impeding its association with IL-2Rβ and IL-2Rγ.
Antiphospholipid antibodies and antiphospholipid syndrome in patients presenting with immune thrombocytopenic purpura: a prospective cohort study
Authors: Diz-Küçükkaya Reyhan , Hacıhanefioǧlu Abdullah , Yenerel Mustafa , Turgut Mehmet , Keskin Hüseyin , Nalçacı Meliha , l˙nanç Murat
Published: July 2002

The pathogenetic role and the clinical importance of the presence of antiphospholipid antibodies (APAs) in patients with immune thrombocytopenic purpura (ITP) are not clear. In this study, the prevalence and clinical significance of APAs were investigated in patients with ITP. Eighty-two newly diagnosed ITP patients were prospectively studied. They were evaluated for the presence of lupus anticoagulant (LA) and immunoglobulin G/M anticardiolipin antibodies (ACAs). Thirty-one patients (37.8%) were APA positive at diagnosis. No statistically significant differences were found between the APA-positive and APA-negative groups regarding gender, initial platelet counts, or response to methylprednisolone therapy. After 5 years of follow-up, cumulative thrombosis-free survival of APA-positive (n = 31) and APA-negative (n = 51) ITP patients was 39% and 97.7%, respectively. A significant difference was found between these groups by log-rank test (P = .0004). In addition, LA was an important risk marker for the development of thrombosis in ITP patients. After a median follow-up of 38 months, 14 ITP patients (45%) who had APA positivity developed clinical features (thrombosis or fetal losses) of antiphospholipid syndrome (APS). There were no differences between the APA-positive patients with and without APS regarding the initial platelet counts, response to the therapy, or ACA positivity. The positivity rate for LA was significantly higher in those patients with ITP who developed APS (χ2: P = .0036; relative risk 7.15; 95% confidence interval, 1.7-47). In conclusion, this study indicates that a significant proportion of patients initially presenting with ITP and APA positivity developed APS. In patients with ITP, the persistent presence of APAs is an important risk factor for the development of APS.
Detection of tryptase in cytoplasmic granules of basophils in patients with chronic myeloid leukemia and other myeloid neoplasms
Authors: Samorapoompichit Puchit , Kiener Hans P. , Schernthaner Gerit-Holger , Jordan John-Hendrik , Agis Hermine , Wimazal Friedrich , Baghestanian Mehrdad , Rezaie-Majd Abdolreza , Sperr Wolfgang R. , Lechner Klaus , Valent Peter
Published: July 2002

Tryptases are serine proteases primarily expressed in mast cells. Normal blood basophils express only trace amounts of the enzyme. However, recent immunohistochemical studies have raised the possibility that neoplastic basophils express significant amounts of tryptase. In this study, tryptase expression was analyzed in normal and neoplastic basophils by immunoelectron microscopy using antitryptase monoclonal antibody G3. Basophils were obtained from patients with chronic myeloid leukemia (CML), idiopathic myelofibrosis (IMF), and myelodysplastic syndrome (MDS), and from healthy donors. Tryptase-immunoreactive material was detected in cytoplasmic granules of basophils in CML, IMF, and MDS. By contrast, normal basophils did not contain significant amounts of tryptase by immunoelectron microscopy. As assessed by reverse transcription-polymerase chain reaction, neoplastic basophils contained messenger RNA (mRNA) for α-tryptase, but no β-tryptase mRNA. In summary, these data provide evidence that neoplastic basophils in CML, IMF, and MDS can express detectable amounts of tryptase. Therefore, tryptase should not be regarded as specific for mast cells when neoplastic myeloid cells are analyzed.
HIV-1 Nef activates STAT1 in human monocytes/macrophages through the release of soluble factors
Authors: Federico Maurizio , Percario Zulema , Olivetta Eleonora , Fiorucci Gianna , Muratori Claudia , Micheli Alessandro , Romeo Giovanna , Affabris Elisabetta
Published: July 2002

Monocytes/macrophages play a predominant role in the immunologic network by secreting and reacting to a wide range of soluble factors. Human immunodeficiency virus (HIV) infection leads to deep immunologic dysfunctions, also as a consequence of alterations in the pattern of cytokine release. Recent studies on in vivo models demonstrated that the expression of HIV Nef alone mimics many pathogenetic effects of HIV infection. In particular, Nef expression in monocytes/macrophages has been correlated with remarkable modifications in the pattern of secreted soluble factors, suggesting that the interaction of Nef with monocytes/macrophages plays a role in the pathogenesis of acquired immunodeficiency syndrome (AIDS). This study sought to define possible alterations in intracellular signaling induced by Nef in monocytes/macrophages. Results demonstrate that HIV-1 Nef specifically activates both α and β isoforms of the signal transducer and activator of transcription 1 (STAT1). This was observed both by infecting human monocyte-derived macrophages (MDMs) with HIV-1 deletion mutants, and by exploiting the ability of MDMs to internalize soluble, recombinant Nef protein (rNef). STAT1-α activation occurs on phosphorylation of both C-terminal Tyr701 and Ser727 and leads to a strong binding activity. Nef-dependent STAT1 activation is followed by increased expression of both STAT1 and interferon regulatory factor-1, a transcription factor transcriptionally regulated by STAT1 activation. It was also established that Nef-induced STAT1- α/β activation occurs through the secretion of soluble factors. Taken together, the results indicate that HIV-1 Nef could interfere with STAT1-governed intracellular signaling in human monocytes/macrophages.