bluuebunny/crossref_metadata_2025 huggingface dataset:
Thrombophilia in sickle cell disease: the red cell connection
Authors: Setty B. N. Yamaja , Rao A. Koneti , Stuart Marie J.
Published: July 2002

Complex pertubations of hemostasis occur in sickle cell disease (SCD). Although the procoagulant property of sickle erythrocytes in vitro is tied to exposure of phosphatidylserine (PS), no study has directly linked this PS positivity to in vivo thrombin generation. This study was designed to determine if thrombin generation in SCD correlates with erythrocyte PS, or whether platelets play a significant role. PS was quantified on erythrocytes and platelets from 40 patients with SCD (SS genotype = 25; SC genotype = 15) and 11 controls. Markers of thrombin generation (prothrombin fragment F1.2; thrombin-antithrombin or TAT complexes) and fibrin dissolution (D-dimer; plasmin-antiplasmin or PAP complexes) were also evaluated. Thrombin generation and activation of fibrinolysis occurred with elevations in F1.2, TAT, and D-dimer. Although numbers of both PS-positive erythrocytes and platelets were elevated, there was no correlation between PS-positive platelets and any hemostatic markers. In contrast, correlations were noted between PS-positive erythrocytes and F1.2 (P < .0002), D-dimer (P < .000002), and PAP (P < .01). Correlations between F1.2 and D-dimer (P < .0001) demonstrated that fibrinolysis was secondary to thrombin generation. In patients with the SC genotype, abnormalities in coagulation, although present, were of a lesser magnitude than in SS disease. This study suggests that the sickle erythrocyte is the cell responsible for the thrombophilic state in SCD because associations between erythrocyte PS and thrombin generation were observed. No such relationship with platelet PS was noted. The use of erythrocyte PS as a surrogate marker in trials testing new therapeutic modalities may provide insights into the vascular complications of SCD.
Targeted deletion of the CD59 gene causes spontaneous intravascular hemolysis and hemoglobinuria
Authors: Holt Dewi S. , Botto Marina , Bygrave Anne E. , Hanna S. Melanie , Walport Mark J. , Morgan B. Paul
Published: July 2002

The glycolipid-anchored glycoprotein CD59 inhibits assembly of the lytic membrane attack complex of complement by incorporation into the forming complex. Absence of CD59 and other glycolipid-anchored molecules on circulating cells in the human hemolytic disorder paroxysmal nocturnal hemoglobinuria is associated with intravascular hemolysis and thrombosis. To examine the role of CD59 in protecting host tissues in health and disease, CD59-deficient (CD59−/−) mice were produced by gene targeting in embryonic stem cells. Absence of CD59 was confirmed by staining cells and tissues with specific antibody. Despite the complete absence of CD59, mice were healthy and fertile. Erythrocytes in vitro displayed increased susceptibility to complement and were positive in an acidified serum lysis test. Despite this, CD59−/− mice were not anemic but had elevated reticulocyte counts, indicating accelerated erythrocyte turnover. Fresh plasma and urine from CD59−/− mice contained increased amounts of hemoglobin when compared with littermate controls, providing further evidence for spontaneous intravascular hemolysis. Intravascular hemolysis was increased following administration of cobra venom factor to trigger complement activation. CD59−/− mice will provide a tool for characterizing the importance of CD59 in protection of self tissues from membrane attack complex damage in health and during diseases in which complement is activated.
Localization of distal regulatory domains in the megakaryocyte-specific platelet basic protein/platelet factor 4 gene locus
Authors: Zhang Chunyan , Thornton Michael A. , Kowalska M. Anna , Sachis Bruce S. , Feldman Michael , Poncz Mortimer , McKenzie Steven E. , Reilly Michael P.
Published: July 2002

The genes for the related human (h) chemokines, PBP (platelet basic protein) and PF4 (platelet factor 4), are within 5.3 kilobases (kb) of each other and form a megakaryocyte-specific gene locus. The hypothesis was considered that the PBP and PF4 genes share a common distal regulatory region(s) that leads to their high-level megakaryocyte-specific expression in vivo. This study examined PBP and PF4 expression in transgenic mice using 4 distinct humanPBP/PF4 gene locus constructs. These studies showed that within the region studied there was sufficient information to regulate tissue-specific expression of both hPBP and hPF4. Indeed this region contained sufficient DNA information to lead to expression levels of PBP and PF4 comparable to the homologous mouse genes in a position-independent, copy number–dependent fashion. These studies also indicated that the DNA domains that led to this expression were distinct for the 2 genes; hPBP expression is regulated by a region that is 1.5 to 4.4 kb upstream of that gene. Expression of hPF4 is regulated by a region that is either intergenic between the 2 genes or immediately downstream of the hPF4 gene. Comparison of the available human and mouse sequences shows conserved flanking region domains containing potential megakaryocyte-related transcriptional factor DNA-binding sites. Further analysis of these regulatory regions may identify enhancer domains involved in megakaryopoiesis that may be useful in the selective expression of other genes in megakaryocytes and platelets as a strategy for regulating hemostasis, thrombosis, and inflammation.
Type I interferons in combination with bacterial stimuli induce apoptosis of monocyte-derived dendritic cells
Authors: Lehner Manfred , Felzmann Thomas , Clodi Katharina , Holter Wolfgang
Published: July 2002

Both type I interferons (IFNs) as well as lipopolysaccharide (LPS) individually compromise selected monocytic or dendritic cell (DC) functions. This study investigates the influence of these agents on the differentiation and the regulation of cell death of monocyte-derived DCs generated in the presence of granulocyte-macrophage colony-stimulating factor plus interleukin-4 (IL-4). It is reported that excessive apoptosis occurred rapidly in monocyte-derived DC cultures, if IFN-α or IFN-β was added in combination with LPS or lipoteichoic acid (LTA). The small fraction of cells surviving in such cultures displayed a mature DC phenotype with expression of CD83, CD80, and CD86. IL-10 was found in the supernatants of monocyte-derived DC cultures, if supplemented with LPS or IFN-α plus LPS but not in control cultures. When monocyte-derived DCs were generated in the presence of IFN-α without LPS, these cells displayed an immature DC phenotype with a reduction of cell recovery but no overt apoptosis. However, the addition of LPS, LTA, LPS plus IFN-γ, or tumor necrosis factor α (TNF-α) plus prostaglandin E2 to such cells again resulted in the rapid induction of apoptosis in the majority of cells, together with a reduced production of IL-12 p70 and TNF-α. Together, these data indicate an exquisite sensitivity of monocyte-derived DCs to activation-induced cell death if generated in the presence of IFN-α, indicating the existence of an important mechanism of immunosuppression caused by IFN-α–inducing agents, such as viral or bacterial stimuli.
Regulated control by granulocyte-macrophage colony-stimulating factor AU-rich element during mouse embryogenesis
Authors: Houzet Laurent , Morello Dominique , Defrance Patrick , Mercier Pascale , Huez Georges , Kruys Véronique
Published: July 2002

In vitro studies have indicated that the granulocyte-macrophage colony-stimulating factor (GM-CSF) gene expression is regulated at the posttranscriptional level by the AU-rich element (ARE) sequence present in its 3′ untranslated region (UTR). This study investigated the importance of the ARE in the control of GM-CSF gene expression in vivo. For this purpose, transgenic mice bearing GM-CSF gene constructs containing or lacking the ARE (GM-CSF AU+ or GM-CSF AU−, respectively) were generated. Both transgenes were under the transcriptional control of the immediate early promoter of the cytomegalovirus (CMV) to ensure their early, widespread, and constitutive expression. The regulation imposed by the ARE was revealed by comparing transgene expression at day 14 of embryonic development (E14); only the ARE-deleted but not the ARE-containing construct was expressed. Although GM-CSF AU+ embryos were phenotypically normal, overexpression of GM-CSF in E14 GM-CSF AU− embryos led to severe hematopoietic alterations such as abnormal proliferation of granulocytes and macrophages accompanied by an increased number of peroxidase-expressing cells, their putative progenitor cells. These abnormalities compromise development because no viable GM-CSF AU− transgenic pups could be obtained. Surprisingly, by E18, significant accumulation of transgene messenger RNA was also observed in GM-CSF AU+ embryos leading to similar phenotypic abnormalities. Altogether, these observations reveal that GM-CSF ARE is a developmentally controlled regulatory element and highlight the consequences of GM-CSF overexpression on myeloid cell proliferation and differentiation.
Growth factor withdrawal from primary human erythroid progenitors induces apoptosis through a pathway involving glycogen synthase kinase-3 and Bax
Authors: Somervaille Tim C. P. , Linch David C. , Khwaja Asim
Published: July 2002

The prevention of apoptosis is a key function of growth factors in the regulation of erythropoiesis. This study examined the role of the constitutively active serine/threonine kinase glycogen synthase kinase-3 (GSK3), a target of the phosphoinositide-3-kinase (PI3K)/Akt pathway, in the regulation of apoptosis in primary human erythroid progenitors. GSK3 phosphorylation at its key regulatory residues S21 (α isoform) and S9 (β isoform) was high in steady-state culture, disappeared on growth factor withdrawal, and returned in response to treatment of cells with either erythropoietin or stem cell factor. Phosphorylation correlated with a PI3K-dependent reduction of 25% to 30% in measured GSK3 activity. LY294002, a specific inhibitor of PI3K, induced apoptosis in growth factor–replete erythroid cells to a degree similar to growth factor deprivation, whereas the Mek1 inhibitor U0126 had no effect, implicating PI3K and not mitogen-activated protein kinase in survival signaling. Growth factor–deprived erythroblasts, which undergo apoptosis rapidly, were protected from apoptosis by both lithium chloride, a GSK3 selective inhibitor, and inhibition of caspase activity. However, the clonogenic potential of single cells, which more accurately reflects cell survival, was maintained by lithium chloride, but not by caspase inhibition. Furthermore, lithium chloride, but not caspase inhibition, prevented the appearance of the conformational form of Bax associated with apoptosis induction. In summary, GSK3 activity is suppressed by erythropoietin and stem cell factor in human erythroid progenitor cells, and increased GSK3 activity, brought about by growth factor withdrawal, may regulate commitment to cell death through a caspase-independent pathway that results in a conformational change in Bax.
Tumor necrosis factor (TNF)–mediated activation of the p55 TNF receptor negatively regulates maintenance of cycling reconstituting human hematopoietic stem cells
Authors: Dybedal Ingunn , Bryder David , Fossum Anna , Rusten Leiv S. , Jacobsen Sten Eirik W.
Published: July 2002

Hematopoietic stem cell (HSC) fate decisions between self-renewal and commitment toward differentiation are tightly regulated in vivo. Recent developments in HSC culture and improvements of human HSC assays have facilitated studies of these processes in vitro. Through such studies stimulatory cytokines critically involved in HSC maintenance in vivo have been demonstrated to also promote HSC self-renewing divisions in vitro. Evidence for negative regulators of HSC self-renewal is, however, lacking. Tumor necrosis factor (TNF), if overexpressed, has been implicated to mediate bone marrow suppression. However, whether and how TNF might affect the function of HSC with a combined myeloid and lymphoid reconstitution potential has not been investigated. In the present studies in vitro conditions recently demonstrated to promote HSC self-renewing divisions in vitro were used to study the effect of TNF on human HSCs capable of reconstituting myelopoiesis and lymphopoiesis in nonobese diabetic–severe combined immunodeficient (NOD-SCID) mice. Although all cord blood and adult bone marrow CD34+CD38− cells were capable of undergoing cell divisions in the presence of TNF, cycling HSCs exposed to TNF in vitro and in vivo were severely compromised in their ability to reconstitute NOD-SCID mice and long-term cultures. The negative effect of TNF was not dependent on the Fas pathway, and a similar effect could be observed using a mutant TNF exclusively targeting the p55 TNF receptor. TNF did not appear to enhance apoptosis or affect cell-cycle distribution of cultured progenitors, but rather promoted myeloid differentiation. Thus, TNF might regulate HSC fate by promoting their differentiation rather than self-renewal.
Randomized comparison of fludarabine, CAP, and ChOP in 938 previously untreated stage B and C chronic lymphocytic leukemia patients
Authors: Leporrier Michel , Chevret Sylvie , Cazin Bruno , Boudjerra Najda , Feugier Pierre , Desablens Bernard , Rapp Marie-José , Jaubert Jerome , Autrand Claudie , Divine Marine , Dreyfus Brigitte , Maloum Karim , Travade Philippe , Dighiero Guillaume , Binet Jacques-Louis , Chastang Claude
Published: July 2002

To comparatively assess first-line treatment with fludarabine and 2 anthracycline-containing regimens, namely CAP (cyclophosphamide, doxorubicin plus prednisone) and ChOP (cyclophosphamide, vincristine, prednisone plus doxorubicin), in advanced stages of chronic lymphocytic leukemia (CLL), previously untreated patients with stage B or C CLL were randomly allocated to receive 6 monthly courses of either ChOP, CAP, or fludarabine (FAMP), stratified based on the Binet stages. End points were overall survival, treatment response, and tolerance. From June 1, 1990 to April 15, 1998, 938 patients (651 stage B and 287 stage C) were randomized in 73 centers. Compared to ChOP and FAMP, CAP induced lower overall remission rates (58.2%; ChOP, 71.5%; FAMP; 71.1%; P < .0001 for each), including lower clinical remission rates (CAP, 15.2%; ChOP, 29.6%; FAMP, 40.1%;P = .003). By contrast, median survival time did not differ significantly according to randomization (67, 70, and 69 months in the ChOP, CAP, and FAMP groups, respectively). Incidences of infections (< 5%) and autoimmune hemolytic anemia (< 2%) during the 6 courses were similar in the randomized groups, whereas fludarabine induced, compared to ChOP and CAP, more frequent protracted thrombocytopenia (P = .003) and less frequent nausea-vomiting (P = .003) and hair loss (P < .0001). For patients with stage B and C CLL first-line fludarabine and ChOP regimens both provided similar overall survival and close response rates, and better results than CAP. However, there was an increase in clinical remission rate and a trend toward a better tolerance of fludarabine over ChOP that may influence the choice between these regimens as front-line treatments in patients with CLL.
Changes in AIDS-related lymphoma since the era of highly active antiretroviral therapy
Authors: Besson Caroline , Goubar Aicha , Gabarre Jean , Rozenbaum Willy , Pialoux Gilles , Châtelet François-Patrick , Katlama Christine , Charlotte Frédéric , Dupont Bertrand , Brousse Nicole , Huerre Michel , Mikol Jacqueline , Camparo Philippe , Mokhtari Karima , Tulliez Micheline , Salmon-Céron Dominique , Boué François , Costagliola Dominique , Raphaël Martine
Published: July 2002

HIV infection is associated with a high incidence of AIDS-related lymphomas (ARLs). Since the use of highly active antiretroviral therapy (HAART), the incidence of AIDS-defining illnesses has decreased, leading to a significant improvement in survival of HIV-infected patients. The consequences of HAART use on ARL are under debate. This study compared the incidence and the characteristics of ARL before and after the use of HAART in a large population of HIV-infected patients in the French Hospital Database on HIV (FHDH) and particularly in 3 centers including 145 patients with proven lymphoma. Within the FHDH, the incidence of systemic ARL has decreased between 1993-1994 and 1997-1998, from 86.0 per 10 000 to 42.9 per 10 000 person-years (P < 10−30). The incidence of primary brain lymphoma has also fallen dramatically between the periods, from 27.8 per 10 000 to 9.7 per 10 000 person-years (P < 10−11). The analysis of 145 cases of ARL in 3 hospitals showed that known HIV history was longer in the second period than in the first period among patients with systemic ARL (98 versus 75 months; P < .01). Patients had a higher number of CD4 cells at diagnosis during the second period (191 versus 63/μL, P = 10−3). Survival of patients with systemic ARL also increased between the periods (from 6 to 20 months; P = .004). Therefore, the profile of ARL has changed since the era of HAART, with a lower incidence of systemic and brain ARL. The prognosis of systemic ARL has improved.
The hypercoagulable state in thalassemia
Authors: Eldor Amiram , Rachmilewitz Eliezer A.
Published: July 2002

Thalassemia is a congenital hemolytic disorder caused by a partial or complete deficiency of α- or β-globin chain synthesis. Homozygous carriers of β-globin gene defects suffer from severe anemia and other serious complications from early childhood. The disease is treated by chronic blood transfusion. However, this can cause severe iron overload resulting in progressive organ failure. Some forms of α thalassemia are also associated with a similar clinical picture. Despite the difficulties associated with treatment, standards of care for thalassemic patients have improved in recent years, resulting in almost doubling of the average life expectancy. As a consequence, additional previously undescribed, complications are now being recognized. In particular, profound hemostatic changes have been observed in patients with β-thalassemia major (β-TM) and β-thalassemia intermedia (β-TI) and also in patients with α thalassemia (hemoglobin H disease). The presence of a higher than normal incidence of thromboembolic events, mainly in β-TI, and the existence of prothrombotic hemostatic anomalies in the majority of the patients, even from a very young age, have led to the recognition of the existence of a chronic hypercoagulable state in thalassemic patients. Despite the appearance of numerous publications on the frequent occurrence of thromboembolic complications in thalassemia, this complication has not been emphasized or comprehensively reviewed. This review summarizes the current literature and discusses possible mechanisms of the lifelong hypercoagulable state that exists in thalassemia.
Genomic structure of the PIK3CG gene on chromosome band 7q22 and evaluation as a candidate myeloid tumor suppressor
Authors: Kratz Christian P. , Emerling Brooke M. , Bonifas Jeannette , Wang Winfred , Green Eric D. , Beau Michelle M. Le , Shannon Kevin M.
Published: July 2002

PIK3CG, which encodes the catalytic subunit p110γ of phosphoinositide 3-OH-kinase-γ (PI3Kγ), has been assigned to chromosome band 7q22, a region that is frequently deleted in myeloid malignancies. PI3Kγ-mutant mice have hematologic defects and are predisposed to colon cancer. On the basis of these data, PIK3CG was evaluated as a candidate myeloid tumor suppressor gene (TSG). PIK3CG was mapped by fluorescence in situ hybridization adjacent and telomeric to a commonly deleted segment defined previously in myeloid leukemias with breakpoints within 7q22. PIK3CG contains 10 exons and spans approximately 37 kilobases of genomic DNA. Forty leukemias with monosomy 7 or a del(7q) were screened for PIK3CG mutations. Two patients had missense variations affecting residue 859 in the N-terminal catalytic domain of the protein. This allele was also detected in unaffected parents and in 1 of 60 control alleles; it probably represents a polymorphism. PIK3CG is unlikely to act as a recessive TSG in myeloid leukemias with monosomy 7.
Real-time quantitation of minimal residual disease in inv(16)-positive acute myeloid leukemia may indicate risk for clinical relapse and may identify patients in a curable state
Authors: Buonamici Silvia , Ottaviani Emanuela , Testoni Nicoletta , Montefusco Vittorio , Visani Giuseppe , Bonifazi Francesca , Amabile Marilina , Terragna Carolina , Ruggeri Deborah , Piccaluga Pier Paolo , Isidori Alessandro , Malagola Michele , Baccarani Michele , Tura Sante , Martinelli Giovanni
Published: July 2002

The inv(16) cytogenetic subtype of acute myeloid leukemia (AML) has a relatively good prognosis. Many patients achieve complete remission (CR). The prognostic uncertainty of negative qualitative reverse transcription–polymerase chain reaction (RT-PCR) assays suggests the need to identify prognostically significant critical thresholds by real-time RT-PCR. A reliable and sensitive (10−5) real-time RT-PCR assay was set up for the evaluation of relevant CBFβ-MYH11/ABL transcript ratios and was applied to the 21 patients with inv(16) AML routinely referred for cytogenetic and molecular monitoring in Seràgnoli Institute (Bologna, Italy) since 1990. Among the 18 patients who underwent ablative chemotherapy, all achieved CR with a 3-year disease-free survival probability of 63% (95% CI, 40%-87%) and no recorded events after 26 months. Five patients had relapses; 2 died of disease and 3 entered second CR. Analysis of the 125 bone marrow (or peripheral blood) samples studied by real-time RT-PCR showed that transcript ratios of samples taken during CR at any time before a relapse were always greater than 0.12%, whereas those of samples taken during first or second CR from patients who did not subsequently have relapses were always less than 0.25%. This suggests that transcript ratios greater than 0.25% may correspond to high risk for relapse, whereas ratios below 0.12% might indicate the patient is in a curable state. If confirmed, such thresholds could open the way to a new phase in post-CR therapeutic decision making for patients with inv(16) AML.
Plasma levels of endothelial protein C receptor respond to anticoagulant treatment
Authors: Stearns-Kurosawa Deborah J. , Swindle Kandice , D'Angelo Armando , Della Valle Patrizia , Fattorini Annalisa , Caron Nathalie , Grimaux Marc , Woodhams Barry , Kurosawa Shinichiro
Published: July 2002

The endothelial protein C receptor (EPCR) facilitates protein C activation and plays a protective role in the response toEscherichia coli–mediated sepsis in primates. Previously, a soluble form of EPCR (sEPCR) in human plasma was characterized, and several studies indicated that generation of sEPCR is regulated by inflammatory mediators, including thrombin-mediated up-regulation of surface metalloproteolytic activity in vitro. This study addressed the question of whether plasma sEPCR levels reflect changes in thrombin generation in patients undergoing anticoagulant treatment. The sEPCR levels in patients treated with coumarin-type oral anticoagulants were significantly lower than those in healthy asymptomatic adult volunteers (105.3 ± 70.8 ng/mL [n = 55] versus 165.8 ± 115.8 ng/mL [n = 200]; P < .0001). A similar decline in plasma sEPCR levels was found in patients treated with unfractionated heparin. In healthy volunteers, sEPCR levels declined to about 100 ng/mL within 3 days after initiation of an 8-day period of warfarin administration and increased within 2 days after its cessation. Plasma sEPCR levels returned to pretreatment values within 1 week, and the changes in plasma sEPCR levels mirrored changes in values for international normalized ratios. A similar decline in sEPCR levels with time was observed in 7 patients beginning treatment with warfarin for a thrombotic disorder. Prothrombin fragment 1 + 2 levels also decreased in volunteers and patients given warfarin. These results show that plasma sEPCR levels decline in response to treatment with anticoagulants whose mechanism of action is known to decrease in vivo thrombin production.
Cooperative binding of c-Myb and Pax-5 activates theRAG-2 promoter in immature B cells
Authors: Kishi Hiroyuki , Jin Zhe-Xiong , Wei Xing-Cheng , Nagata Takuya , Matsuda Tadashi , Saito Shigeru , Muraguchi Atsushi
Published: July 2002

The recombination activating gene-1 (RAG-1) andRAG-2 are expressed specifically in immature lymphoid cells undergoing the recombination of antigen receptor genes. The regulation of murine RAG-2 promoter was studied and it was revealed that the −41/−17 RAG-2 promoter region, which is conserved between humans and mice, was indispensable for theRAG-2 promoter activity in B-cell lines. The region contained 2 cis elements that bound c-Myb and Pax-5. Mutation in the c-Myb–binding site in the promoter reduced the promoter activity in B-cell lines. Cooperative activation of theRAG-2 promoter was seen by a combination of c-Myb and Pax-5 in a human embryonic kidney cell line (293T), via their synergistic DNA-binding. Deletion experiments showed that the C-terminus of c-Myb was responsible for their interaction. Furthermore, the dominant-negative c-Myb mutant suppressed the activation of theRAG-2 promoter in a pre–B-cell line as well as in 293T cells. These results suggest that cooperative binding of c-Myb and Pax-5 to the RAG-2 promoter is one of the mechanisms to direct the restricted expression of the RAG-2 in immature B cells.
Adenosine deaminase deficiency with mosaicism for a “second-site suppressor” of a splicing mutation: decline in revertant T lymphocytes during enzyme replacement therapy
Authors: Arredondo-Vega Francisco X. , Santisteban Ines , Richard Eva , Bali Pawan , Koleilat Majed , Loubser Michael , Al-Ghonaium Abdulaziz , Al-Helali Mariam , Hershfield Michael S.
Published: July 2002

Four patients from 3 Saudi Arabian families had delayed onset of immune deficiency due to homozygosity for a novel intronic mutation, g.31701T>A, in the last splice acceptor site of the adenosine deaminase (ADA) gene. Aberrant splicing mutated the last 4 ADA amino acids and added a 43-residue “tail” that rendered the protein unstable. Mutant complementary DNA (cDNA) expressed inEscherichia coli yielded 1% of the ADA activity obtained with wild-type cDNA. The oldest patient, 16 years old at diagnosis, had greater residual immune function and less elevated erythrocyte deoxyadenosine nucleotides than his 4-year-old affected sister. His T cells and Epstein-Barr virus (EBV) B cell line had 75% of normal ADA activity and ADA protein of normal size. DNA from these cells and his whole blood possessed 2 mutant ADA alleles. Both carried g.31701T>A, but one had acquired a deletion of the 11 adjacent base pair, g.31702-12, which suppressed aberrant splicing and excised an unusual purine-rich tract from the wild-type intron 11/exon 12 junction. During ADA replacement therapy, ADA activity in T cells and abundance of the “second-site” revertant allele decreased markedly. This finding raises an important issue relevant to stem cell gene therapy.
Acute promyelocytic leukemia: evolving therapeutic strategies
Authors: Tallman Martin S. , Nabhan Chadi , Feusner James H. , Rowe Jacob M.
Published: July 2002

Acute promyelocytic leukemia (APL) is now the most curable subtype of acute myeloid leukemia in adults. All-trans retinoic acid (ATRA), which induces differentiation of the leukemic cells into mature granulocytes, represents the important advance. The incorporation of ATRA in induction results in a high complete remission rate, leads to rapid resolution of the characteristic life-threatening coagulopathy, and, most importantly, decreases the relapse rate compared with treatment with chemotherapy alone. However, ATRA is associated with unique toxicities not observed with conventional cytotoxic chemotherapy. A number of clinical trials have been performed to define the optimal role of ATRA in the treatment of patients. The therapeutic strategies have rapidly evolved as a result of both single institution and large cooperative group trials. Arsenic trioxide and stem cell transplantation are effective treatments for patients with APL who relapse after or are refractory to ATRA-based therapy. As experience with ATRA and arsenic trioxide in patients with APL accumulates, a number of important questions arise that need to be addressed.
Therapy-related myelodysplastic syndrome–acute myelogenous leukemia in patients treated for acute promyelocytic leukemia: an emerging problem
Authors: Latagliata Roberto , Petti Maria Concetta , Fenu Susanna , Mancini Marco , Spiriti Maria Antonietta Aloe , Breccia Massimo , Brunetti Gregorio A. , Avvisati Giuseppe , Coco Francesco Lo , Mandelli Franco
Published: July 2002

The use of all-trans retinoic acid (ATRA) in combination with chemotherapy has markedly improved the prognosis for patients with acute promyelocytic leukemia (APL); the higher complete remission (CR) and survival rates now reported in this disease almost approach those obtained for other highly curable hematologic malignancies. Of 77 patients with APL who were consecutively treated at a single institution and who achieved CR after induction and consolidation therapy, 5 (6.5%) acquired therapy-related myelodysplasia (tMDS), acute myelogenous leukemia (AML), or both (tMDS–AML). Of these, 3 of 46 (6.5%) patients received front-line chemotherapy with or without ATRA and acquired tMDS–AML while in first remission of APL. Two underwent repeated chemotherapy cycles with ATRA because of APL relapse and acquired tMDS–AML while in the second or third remission of APL. In 2 patients, clinical and biologic characteristics of tMDS–AML were as expected for postalkylating forms (long latency, MDS phase preceding AML, karyotypic aberrations involving chromosomes 5 or 7), even though one of them had not previously received alkylating drugs. Three of the 5 patients died shortly after tMDS–AML diagnosis, one is alive with tMDS, and one is alive and in CR after allogeneic bone marrow transplantation. The occurrence of tMDS–AML after successful therapy for APL is an emerging problem. The availability of prognostic score systems at initial diagnosis and monitoring of residual disease by polymerase chain reaction might allow better tailoring of treatment intensity in APL to spare unnecessary toxicity and to minimize the risk for tMDS–AML in patients who are presumably cured.
The chimeric anti-CD20 antibody rituximab induces apoptosis in B-cell chronic lymphocytic leukemia cells through a p38 mitogen activated protein–kinase–dependent mechanism
Authors: Pedersen Irene Munk , Buhl Anne Mette , Klausen Pia , Geisler Christian H. , Jurlander Jesper
Published: July 2002

Antibodies against CD20 can activate complement and induce antibody-dependent cellular cytotoxicity (ADCC) in B lymphocytes. In B-cell lines, such antibodies also induce apoptosis. In this study, the expression and function of CD20 on B-cell chronic lymphocytic leukemia (B-CLL) cells were analyzed. Flow cytometric analysis demonstrated that B-CLL cells express CD20 with a fluorescence intensity that is significantly weaker than that of normal CD5+ and CD5− B cells and that of malignant CD5− low-grade non-Hodgkin lymphoma cells. A small population of cells from healthy donors that have an expression pattern of CD5 and CD20 identical to that of B-CLL cells were identified, and this population was confirmed to be of T lineage, not B lineage. Culture of freshly isolated B-CLL cells in the presence of the chimeric anti-CD20 antibody rituximab and a cross-linking F(ab)2 fragment, resulted in dose- and time-dependent induction of apoptosis. The induction of apoptosis occurred under conditions in which the influence of complement activation and ADCC was negligible. Cross-linking of rituximab induced strong and sustained phosphorylation of the 3 mitogen activated protein (MAP) kinases c-Jun NH2-terminal protein kinase, extracellular signal–regulated kinase, and p38. Introduction of the p38 inhibitor SB203580 into the system completely blocked signaling downstream of p38, as evidenced by the absence of MAPKAP K2 activity, and significantly reduced the degree of anti-CD20–induced apoptosis. These results demonstrate that cross-linking of rituximab bound to CD20 on freshly isolated B-CLL cells induces apoptosis through a signaling pathway that is dependent on p38 MAP-kinase activation.
Effects of anagrelide on in vivo megakaryocyte proliferation and maturation in essential thrombocythemia
Authors: Tomer Aaron
Published: July 2002

To define the mechanism by which anagrelide normalizes the platelet count in essential thrombocythemia, we studied in vivo megakaryocytopoiesis in 10 newly diagnosed patients prior to and while on anagrelide therapy. Using flow cytometric analysis of aspirated marrow, megakaryocytopoiesis was quantified and correlated with the autologous platelet production rate. Megakaryocytes were identified by CD41a expression and enumerated in relation to the nucleated marrow erythroid precursors. Megakaryocyte diameters were directly measured by time-of-flight technique, and cell ploidy was measured by DNA staining. Two to 3 thousand megakaryocytes were analyzed in each sample. In the 10 patients, the platelet count was 1063 ± 419 × 109platelets/L (mean ± 1 SD) with markedly increased production (237 ± 74 × 109 platelets/L per day versus 43.1 ± 8.4 × 109 platelets/L per day in healthy individuals). The platelet survival was 8.2 ± 1.1 days versus 9.0 ± 0.5 days in healthy controls (P > .05). Megakaryocyte diameter was increased to 46 μm (versus 37 μm in controls; range, 21 μm for 2N to 56 μm for 64N cells). The volume increased to 48 × 103 μm3 versus 26 × 103 μm3 in controls, and the number increased to 14 × 106/kg (versus 7 × 106/kg in controls), resulting in 3.7-fold increase in megakaryocyte mass (66 × 1010 μm3/kg versus 18 × 1010 μm3/kg). Cell ploidy was enhanced showing a modal ploidy of 32N (versus 16N in healthy controls) with marked increase in 64N and 128N cells (P < .05). Anagrelide therapy reduced the platelet counts to 361 ± 53 × 109 platelets/L and the turnover rate to 81 × 109 platelets/L per day. The platelet survival was unchanged. Following therapy, megakaryocyte number decreased to 8 × 106/kg, diameter to 40 μm, and volume to 34 × 103 μm3 with a normalized modal ploidy of 16N, resulting in a megakaryocyte mass reduced by 60% (28 × 1010 μm3/kg;P < .05). This reduction in cell mass closely correlated with the reduction in platelet count and production rate by 66% (r = 0.96). The present data indicate that in essential thrombocythemia anagrelide therapy decreases circulating platelets by reducing both megakaryocyte hyperproliferation and differentiation.
Bone marrow progenitor cell reserve and function and stromal cell function are defective in rheumatoid arthritis: evidence for a tumor necrosis factor alpha–mediated effect
Authors: Papadaki Helen A. , Kritikos Heraklis D. , Gemetzi Claudia , Koutala Helen , Marsh Judith C. W. , Boumpas Dimitrios T. , Eliopoulos George D.
Published: July 2002

Based on previous reports for impaired hematopoiesis in rheumatoid arhrtitis (RA), and in view of the current interest in exploring the role of autologous stem cell transplantation (ASCT) as an alternative treatment in patients with resistant disease, we have evaluated bone marrow (BM) progenitor cell reserve and function and stromal cell function in 26 patients with active RA. BM progenitor cells were assessed using flow cytometry and clonogenic assays in short-term and long-term BM cultures (LTBMCs). BM stroma function was assessed by evaluating the capacity of preformed irradiated LTBMC stromal layers to support the growth of normal CD34+ cells. We found that RA patients exhibited low number and increased apoptosis of CD34+ cells, defective clonogenic potential of BM mononuclear and purified CD34+ cells, and low progenitor cell recovery in LTBMCs, compared with healthy controls (n = 37). Patient LTBMC stromal layers failed to support normal hematopoiesis and produced abnormally high amounts of tumor necrosis factor alpha (TNFα). TNFα levels in LTBMC supernatants inversely correlated with the proportion of CD34+ cells and the number of colony-forming cells, and positively with the percentage of apoptotic CD34+ cells. Significant restoration of the disturbed hematopoiesis was obtained following anti-TNFα treatment in 12 patients studied. We concluded that BM progenitor cell reserve and function and BM stromal cell function are defective in RA probably due, at least in part, to a TNFα-mediated effect. The role of these abnormalities on stem cell harvesting and engraftment in RA patients undergoing ASCT remains to be clarified.
Randomized Trial of Cisplatin and Ifosfamide With or Without Bleomycin in Squamous Carcinoma of the Cervix: A Gynecologic Oncology Group Study
Authors: Bloss Jeffrey D. , Blessing John A. , Behrens Brent C. , Mannel Robert S. , Rader Janet S. , Sood Anil K. , Markman Maurie , Benda Jo
Published: July 2002

PURPOSE: Phase II trial reports have suggested that the addition of bleomycin to the combination of cisplatin and ifosfamide may improve response rates and possible survival in squamous carcinoma of the cervix. This study prospectively evaluates the combination of bleomycin to this regimen in women with histologically proven advanced recurrent or persistent squamous cell carcinoma of the cervix.

PATIENTS AND METHODS: Eligible women were randomized to receive either cisplatin (50 mg/m2), ifosfamide (5 g/m2 over 24 hours), and mesna (6 g/m2 during ifosfamide infusion and the following 12 hours) (CI) versus bleomycin 30 units over 24 hours on day 1 followed by cisplatin (50 mg/m2), ifosfamide (5 g/m2 over 24 hours), and mesna (6 g/m2 during ifosfamide infusion and the following 12 hours) (CIB). Three hundred three women were enrolled onto this trial, of which 287 were assessable.

RESULTS: There were no significant differences between CI and CIB with regard to response rates (32% v 31.2%, respectively), progression-free survival (PFS), or overall survival. PFS and survival were associated with initial performance status (PS). Patients with a PS of 0 experienced a lower rate of failure (P = .013) and a lower risk of death (P = .009) compared with patients with PS of 2. The most frequent grade 3/4 toxicities were leukopenia, neutropenia, anemia, thrombocytopenia, and nausea and vomiting. Neither regimen was associated with a significant increase in incidence of these toxicities.

CONCLUSION: The CI regimen was virtually identical to CIB with regard to response rate, PFS, survival, and toxicity profile. Thus, the addition of bleomycin in the dose-schedule employed to cisplatin and ifosfamide did not improve outcome in patients with advanced cervical cancer.
Carcinoembryonic Antigen as a Target for Therapeutic Anticancer Vaccines: A Review
Authors: Berinstein Neil L.
Published: July 2002

PURPOSE: To describe the features of carcinoembryonic antigen (CEA) that are important for its use in vaccination approaches and review the clinical experience with therapeutic vaccines targeting CEA.

METHODS: A PubMed search was performed on CEA, along with various qualifiers such as cancer vaccines, epitopes, and function. Relevant articles were reviewed.

RESULTS: CEA is a member of the immunoglobulin supergene family and may play a role in tumorigenesis. CEA protein is processed and presented on major histocompatibility complex (MHC) proteins for multiple alleles, including HLA A2, A3, and A24. T lymphocytes from healthy volunteers and cancer patients can recognize the processed epitopes of CEA and can become activated to lyse CEA-expressing tumors. Therapeutic vaccination approaches that have targeted CEA include vaccination with recombinant CEA protein, CEA anti-idiotype antibodies, and dendritic cells pulsed with agonist epitopes of CEA. Humoral responses have predominantly been induced with the first two approaches, whereas CD4 and CD8 responses, disease stabilization, and even objective clinical responses have been seen with the dendritic cell approach. Recently, CEA-poxvirus vectors encoding CEA and costimulatory molecules such as B7.1 have been shown to be safe and to induce increases in the frequency of T-cell precursors that recognize processed epitopes of CEA presented on MHC class 1 molecules. Disease stabilization has been seen in up to 37% of patients treated with these vaccines.

CONCLUSION: Tolerance to CEA in patients with cancer can be overcome with several different vaccination approaches, and such vaccinations are safe and immunologically active. Poxvirus-based vaccines can reproducibly generate T-cell responses to CEA and to tumors expressing CEA. Clinical activity has been seen with poxvirus or dendritic cell approaches. Other approaches are also being explored.
Impact of PbZr0.5Ti0.5O3 Particle Size on the Ferroelectric and Magnetoelectric Properties of Mn0.5Zn0.5Fe2O4–PbZr0.5Ti0.5O3 Multiferroic Fluids
Authors: Ao Hong , Mu Haowen , Chen Chen , Li Huan , Gao Rongli , Deng Xiaoling , Cai Wei , Fu Chunlin
Published: December 2024

Herein, the impact of varying particle sizes of PbZr0.5Ti0.5O3 (PZT) powders on the ferroelectric and magnetoelectric properties of Mn0.5Zn0.5Fe2O4–PbZr0.5Ti0.5O3 multiferroic fluids is investigated. The PZT ferroelectric powders with different particle sizes (0.36, 0.28, 0.31, 0.75, 1.20 μm) are successfully prepared by altering the ball milling time. The multiferroic fluids demonstrate overall good sedimentation stability. The study finds that the dielectric constant first decreases and then increases with the reduction in particle size. The ferroelectric properties improve with the decrease in particle size and the application of a magnetic field. The multiferroic fluids with a particle size of 0.36 μm exhibit the highest polarization change (960.37%) under an electric field of 2000 Hz, 20 kV cm−1, and a magnetic field of 700 Oe. Furthermore, the magnetoelectric coupling coefficient first increases and then decreases with the reduction of the ferroelectric particle size. The multiferroic fluids with a particle size of 0.36 μm demonstrate the highest magnetoelectric coupling coefficient of 17.22 V cm−1 Oe−1 at 2000 Hz, indicating superior magnetoelectric coupling performance. These findings provide valuable insights into optimizing multiferroic fluids for applications requiring a high magnetoelectric coupling effect.
Sustainable Fabrication and Transfer of High‐Precision Nanoparticle Arrays Using Recyclable Chemical Pattern Templates
Authors: Zha Huaining , Zhang Wenjie , Chen Peng , Tao Jing , Qiu Li , Yang Fan , Ye Shunsheng , Sang Yutao , Nie Zhihong
Published: December 2024

Nanoparticle (NP) arrays, particularly those with plasmonic properties, have diverse applications in electronics, photonics, catalysis, and biosensing, but their precise and scalable fabrication remains challenging. In this work, a facile chemical‐based strategy is presented for the fabrication of precise NP patterns using a combination of soft thermal nanoimprinting and template‐directed assembly. The approach enables the creation of well‐defined NP arrays with single‐particle resolution and yields over 99%, covering a diverse range of NP sizes from 30 to 150 nm. These patterns can be transferred onto various substrates including semiconductors, insulators, 2D materials, and flexible polymers, maintaining high uniformity and repeatability for over 60 cycles with minimal degradation. Moreover, the method enables the fabrication of extensive NP arrays up to 1 cm2 with a positional accuracy of ±11 nm for 30 nm NPs. As a result, the obtained silver NP arrays exhibit ultranarrow surface lattice resonances with a linewidth of 4 nm and a quality factor (Q) of 216. The method offers new avenues for the creation of plasmonic NP arrays for flexible and wearable devices.
Liver organoids: From 3D printing to biomedical applications
Authors: Shi Ying , Han Xin , Zhang Zheng , Xu Jiangtao , Liu Guozhen
Published: December 2024

The liver is an immune organ, especially an immune tolerance organ. The critical shortage of donor organs and disease models for the treatment of end‐stage liver failure underscores the urgent need for the generation of liver organoids from human induced pluripotent stem cells (iPSCs). Notably, significant advancements have been made in the study of liver organoids over the past decade. The construction of liver organoids has transitioned from single cell type to multicellular models, and from two‐dimensional to three‐dimensional cultures. Here we provide the progress surrounding the different liver organoids culture techniques from 3D printing to organ‐on‐chip, as well as focuses on the present and future applications of liver organoids, and then to present challenges and perspectives ahead for further advancement.
Classifying Female Sexual Homicide Offenders: A Latent Class Analysis of Murder Arrestees in the U.S.
Authors: Chan Heng Choon (Oliver) , DeLisi Matt , Edgemon Timothy G.
Published: December 2024

Research on sexual homicides has primarily focused on male offenders, and thus little is known about female offenders who perpetrated sexual homicides. This study aimed to develop the first statistical classification of female single‐victim (SV) sexual homicide offenders (SHOs) using the U.S. FBI's Supplementary Homicide Reports database that spanned over a 47‐year period (1976–2022). A latent class analysis (LCA) was computed to detect subtypes of female SHOs in a sample of 158 offenders. Findings of the LCA identified two unique classes of female SHOs exist within the data: White intra‐familial offenders and Black extra‐familial offenders. The distinguishing features of these two classes were the offender's racial group, the victim's age and racial groups, the offender‐victim relationship, the geographical urbanness level of crime location, and weapon use. This empirically‐derived offender classification can be informative to law enforcement agents and security professionals in their investigative strategies.
Methods of nivolumab administration in advanced melanoma: A comparison of patients’ clinical outcomes treated with flat dose or weight‐adjusted dose, a multicenter observational study
Authors: Le Brun Iona Campo , Dalle Séphane , Mortier Laurent , Dereure Olivier , Rat Sophie Dalac , Dutriaux Caroline , Leccia Marie‐Thérèse , Legoupil Delphine , Montaudié Henri , De Quatrebarbes Julie , Gaudy‐Marqueste Caroline , Maubec Eve , Saiag Philippe , Pagès Cécile , Possenti Florence Brunet , Granel‐Brocard Florence , Porcher Raphaël , Lefevre Wendy , Lebbé Célèste , Kempf Emmanuelle
Published: December 2024

Background

Nivolumab obtained approval in advanced melanoma (AM) with weight‐adjusted dose (WAD) administration (3 mg/kg/2 weeks). In 2018, the dosage regimen was changed to flat dose (FD) administration (240 mg/2 weeks or 480 mg/4 weeks) based on a modeling study, without clinical data.

Methods

AM patients have been prospectively included in the French national multicenter MelBase database since 2013. First‐line patients treated with nivolumab monotherapy were included in the WAD or FD groups of this study. The primary end point was the incidence of grade ≥3 immune‐related adverse events (irAEs). Secondary end points were incidence of any grade irAEs, and overall survival (OS) and progression‐free survival (PFS). Inverse probability of treatment weighting was used to balance groups on their baseline characteristics.

Results

Between 2015 and 2022, 348 patients were included: 160 in the WAD and 188 in the FD groups. In the FD group, 45% and 27% of patients weighed <75 kg and >85 kg, respectively. Grade ≥3 and any grade irAEs rates were 13.1% versus 11.7% (p = .8) and 63.1% versus 67.0% (p = .5) in the WAD and FD groups, respectively. After weighting, median PFS was 3.1 and 3.7 months (hazard ratio [HR], 0.84; 95% confidence interval [CI], 0.65–1.07), and median OS was 24.8 and 37.0 months (HR, 0.74; 95% CI, 0.54–1.01) in the WAD and FD groups, respectively.

Conclusions

There was no difference in the incidence of severe irAEs and in median PFS between AM patients treated by WAD or FD nivolumab. The median OS between patient groups did not reach statistical significance.