bluuebunny/crossref_metadata_2025 huggingface dataset:
IL-15 induces antigen-independent expansion and differentiation of human naive CD8+ T cells in vitro
Authors: Alves Nuno L. , Hooibrink Berend , Arosa Fernando A. , van Lier René A. W.
Published: June 2003

Recent studies in mice have shown that although interleukin 15 (IL-15) plays an important role in regulating homeostasis of memory CD8+ T cells, it has no apparent function in controlling homeostatic proliferation of naive T cells. We here assessed the influence of IL-15 on antigen-independent expansion and differentiation of human CD8+ T cells. Both naive and primed human T cells divided in response to IL-15. In this process, naive CD8+ T cells successively down-regulated CD45RA and CD28 but maintained CD27 expression. Concomitant with these phenotypic changes, naive cells acquired the ability to produce interferon γ (IFN-γ) and tumor necrosis factor α (TNF-α), expressed perforin and granzyme B, and acquired cytotoxic properties. Primed CD8+ T cells, from both noncytotoxic (CD45RA-CD27+) and cytotoxic (CD45RA+CD27-) subsets, responded to IL-15 and yielded ample numbers of cytokine-secreting and cytotoxic effector cells. In summary, all human CD8+ T-cell subsets had the ability to respond to IL-15, which suggests a generic influence of this cytokine on CD8+ T-cell homeostasis in man. (Blood. 2003;102:2541-2546)
Recombinant BβArg14His fibrinogen implies participation of N-terminus of Bβ chain in desA fibrin polymerization
Authors: Moen Jennifer L. , Gorkun Oleg V. , Weisel John W. , Lord Susan T.
Published: June 2003

We synthesized BβArg14His fibrinogen with histidine substituted for arginine at the Bβ thrombin-cleavage site. This substitution led to a 300-fold decrease in the rate of thrombin-catalyzed fibrinopeptide B (FpB, Bβ 1-14) release, whereas the rate of FpA release was normal with either thrombin or the FpA-specific enzyme, batroxobin. Both thrombin- and batroxobincatalyzed polymerization of BβArg14His fibrinogen were significantly impaired, with a longer lag time, slower rate of lateral aggregation, and decreased final turbidity. Moreover, desA monomer polymerization was similarly impaired, demonstrating that the histidine substitution itself, and not the lack of FpB cleavage, caused the abnormal polymerization of BβArg14His fibrin. Scanning electron microscopy showed BβArg14His fibrin fibers were thinner than normal (BβArg14His, approximately 70 nm; normal, approximately 100 nm; P < .0001), as expected from the decreased final turbidity. We conclude that the N-terminus of the Bβ chain is involved in the lateral aggregation of normal desAprotofibrils and that the Arg→His substitution disrupts these interactions in BβArg14His fibrinogen. (Blood. 2003;102:2466-2471)
A gene-deleted adenoviral vector results in phenotypic correction of canine hemophilia B without liver toxicity or thrombocytopenia
Authors: Ehrhardt Anja , Xu Hui , Dillow Aaron M. , Bellinger Dwight A. , Nichols Timothy C. , Kay Mark A.
Published: June 2003

Many approaches for treating hemophilia via gene transfer have been attempted in large animal models but all have potential drawbacks. Recombinant adenoviral vectors offer high-efficiency transfer of an episomal vector but have been plagued by the cytotoxicity/immunogenicity of early-generation vectors that contain viral genes. In our current study, we have used a nonintegrating helper-dependent (HD) adenoviral vector for liver-directed gene transfer to achieve hemostatic correction in a dog with hemophilia B. We measured plasma canine factor IX (cFIX) concentrations at a therapeutic range for up to 2.5 months and normalization of the whole blood clotting time (WBCT) for about a month. This was followed by a decrease and stabilized partial correction for 4.5 months. Hepatic gene transfer of a slightly lower dose of the HD vector resulted in WBCTs that were close to normal for 2 weeks, suggesting a dose threshold effect in dogs. In sharp contrast to other studies using first- or second-generation adenoviral vectors, we observed no vector-related elevation of liver enzymes, no fall in platelet counts, and normal liver histology. Taken together, this study demonstrates that injection of an adenoviral HD vector results in complete but transient phenotypic correction of FIX deficiency in canine models with no detectable toxicity. (Blood. 2003;102:2403-2411)
Rapid expansion of cytomegalovirus–specific cytotoxic T lymphocytes by artificial antigen-presenting cells expressing a single HLA allele
Authors: Papanicolaou Genovefa A. , Latouche Jean-Baptiste , Tan Cuiwen , Dupont Jakob , Stiles Jeffrey , Pamer Eric G. , Sadelain Michel
Published: June 2003

Cytomegalovirus (CMV) is a major threat in patients undergoing allogeneic bone marrow transplantation. The adoptive transfer of CMV-specific cytotoxic T lymphocytes (CTLs) expanded from the blood of CMV-seropositive donors has been shown to effectively control CMV infection. However, the requirement for safe and effective antigen-presenting cells (APCs) for each patient precludes broad applicability of this successful form of therapy. Here we analyze the ability of artificial APCs (AAPCs) to activate and expand CMV-specific CTLs from peripheral blood of seropositive HLA A2.1+ donors. We demonstrate that AAPCs expressing the CMV P495 peptide or the full-length pp65 protein stimulate P495-specific CTLs at least as effectively as autologous, peptide-pulsed, peripheral blood mononuclear cells or EBV-transformed B cells. Starting from 100 mL of blood, the AAPCs reliably yield clinically relevant CTL numbers after a single stimulation. CTLs activated on AAPCs effectively kill CMV-infected fibroblasts and have a Tc1 memory effector phenotype identical to that of CTLs generated with autologous APCs. AAPCs thus offer a rapid, controlled, convenient, and highly reproducible system for expanding CMV-specific CTLs. Furthermore, the CTL expansion obtained with AAPCs encoding full-length pp65 indicates that AAPCs may be used to present known as well as unknown CTL epitopes in the context of the AAPC's HLA. (Blood. 2003;102:2498-2505)
AML with 11q23/MLL abnormalities as defined by the WHO classification: incidence, partner chromosomes, FAB subtype, age distribution, and prognostic impact in an unselected series of 1897 cytogenetically analyzed AML cases
Authors: Schoch Claudia , Schnittger Susanne , Klaus Mirjam , Kern Wolfgang , Hiddemann Wolfgang , Haferlach Torsten
Published: June 2003

Acute myeloid leukemia (AML) cases with 11q23 abnormalities involving the MLL gene comprise one category of recurring genetic abnormalities in the WHO classification. In an unselected series of 1897 AML cases, 54 patients with an 11q23/MLL rearrangement were identified, resulting in an incidence of 2.8%. The incidence of AML with MLL rearrangement was significantly higher in therapy-related AML (t-AML) than in de novo AML (9.4% vs 2.6%, P < .0001). The frequency of MLL rearrangements was significantly higher in patients younger than 60 years (5.3% vs 0.8%, P < .0001). While the incidence of MLL rearrangements in AML M4, M5a, and M5b was 4.7%, 33.3%, and 15.9%, respectively, it was found in only 0.9% of all other French-American-British (FAB) subtypes (P < .0001). Compared with AML with intermediate karyotype, AML with 11q23/MLL rearrangement had a worse outcome, which was rather comparable with AML with unfavorable karyotype. Compared with t-AML, the median overall survival (OS) of de novo AML with MLL rearrangement was significantly better (2.5 vs 10 months, P = .0143). No significant differences in median OS were observed between cases with t(9;11) compared with all other MLL rearrangements (10.0 vs 8.9 months, P = .36). In conclusion, the category AML with 11q23/MLL abnormalities accounts for 2.8% of unselected AML, is closely associated with monocytic differentiation, and has a dismal prognosis. (Blood. 2003;102:2395-2402)
The recurrent IgH translocations are highly associated with nonhyperdiploid variant multiple myeloma
Authors: Fonseca Rafael , Debes-Marun Carina S. , Picken Elisa B. , Dewald Gordon W. , Bryant Sandra C. , Winkler Jerry M. , Blood Emily , Oken Martin M. , Santana-Dávila Rafael , González-Paz Natalia , Kyle Robert A. , Gertz Morie A. , Dispenzieri Angela , Lacy Martha Q. , Greipp Philip R.
Published: June 2003

Aneuploid is ubiquitous in multiple myeloma (MM), and 4 cytogenetic subcategories are recognized: hypodiploid (associated with a shorter survival), pseudodiploid, hyperdiploid, and near-tetraploid MM. The hypodiploid, pseudodiploid, and near-tetraploid karyotypes can be referred to as the nonhyperdiploid MM. Immunoglobulin heavy-chain (IgH) translocations are seen in 60% of patients. We studied the relation between aneuploidy and IgH translocations in MM. Eighty patients with MM and abnormal metaphases were studied by means of interphase fluorescent in situ hybridization (FISH) to detect IgH translocations. We also studied a second cohort of 199 patients (Eastern Cooperative Oncology Group [ECOG]) for IgH translocations, chromosome 13 monosomy/deletions (Δ13), and ploidy by DNA content. Mayo Clinic patients with abnormal karyotypes and FISH-detected IgH translocation were more likely to be nonhyperdiploid (89% versus 39%, P < .0001). Remarkably, 88% of tested patients with hypodiploidy (16 of 18) and 90% of tested patients with tetraploidy (9 of 10) had an IgH translocation. ECOG patients with IgH translocations were more likely to have nonhyperdiploid MM by DNA content (68% versus 21%, P < .001). This association was seen predominantly in patients with recurrent chromosome partners to the IgH translocation (11q13, 4p16, and 16q23). The classification of MM into hyperdiploidy and nonhyperdiploidy is dictated largely by the recurrent (primary) IgH translocations in the latter. (Blood. 2003;102:2562-2567)
The protein kinase C inhibitor RO318220 potentiates thrombin-stimulated platelet-supported prothrombinase activity
Authors: London Fredda S.
Published: June 2003

Prothrombinase activity was tested on thrombin- and SFLLRN-activated platelets treated with RO318220, a potent inhibitor of protein kinase C. RO318220 completely inhibited platelet dense and α-granule secretion at a concentration of 20 μM but had no effect on prothrombinase activity in the presence of excess factor Va (20 nM). This indicates that protein kinase C activity and agonist-initiated secretion are not necessary for the development of a procoagulant surface. Treatment with 75 to 150 μM RO318220 potentiated platelet-supported thrombin generation up to 280% of control platelets with no change in Kd appFXa. Treated with increasing concentrations of RO318220, an increasing proportion of thrombin-stimulated platelets bound annexin V with decreasing binding sites per platelet. A lower mean forward scatter (FSC-H) of platelets treated with RO318220 suggested platelet vesiculation as a result of RO318220 treatment; however, 100 μM calpeptin pretreatment eliminated the decrease in FSC-H without affecting either the increase in platelets positive for annexin V binding, the decrease in binding sites per platelet, or the 3-fold increase in prothrombinase activity. Thus, RO318220 appears to increase prothrombinase activity by increasing platelet responsiveness to thrombin rather than by inducing platelet vesiculation. This suggests that RO318220 inhibits a signaling molecule within a negative regulatory pathway that governs platelet procoagulant surface changes. (Blood. 2003;102:2472-2481)
Labile plasma iron in iron overload: redox activity and susceptibility to chelation
Authors: Esposito Breno P. , Breuer William , Sirankapracha Pornpan , Pootrakul Pensri , Hershko Chaim , Cabantchik Z. Ioav
Published: June 2003

Plasma non-transferrin-bound-iron (NTBI) is believed to be responsible for catalyzing the formation of reactive radicals in the circulation of iron overloaded subjects, resulting in accumulation of oxidation products. We assessed the redox active component of NTBI in the plasma of healthy and β-thalassemic patients. The labile plasma iron (LPI) was determined with the fluorogenic dihydrorhodamine 123 by monitoring the generation of reactive radicals prompted by ascorbate but blocked by iron chelators. The assay was LPI specific since it was generated by physiologic concentrations of ascorbate, involved no sample manipulation, and was blocked by iron chelators that bind iron selectively. LPI, essentially absent from sera of healthy individuals, was present in those of β-thalassemia patients at levels (1-16 μM) that correlated significantly with those of NTBI measured as mobilizer-dependent chelatable iron or desferrioxamine chelatable iron. Oral treatment of patients with deferiprone (L1) raised plasma NTBI due to iron mobilization but did not lead to LPI appearance, indicating that L1-chelated iron in plasma was not redox active. Moreover, oral L1 treatment eliminated LPI in patients. The approach enabled the assessment of LPI susceptibility to in vivo or in vitro chelation and the potential of LPI to cause tissue damage, as found in iron overload conditions. (Blood. 2003;102:2670-2677)
Hfe deficiency increases susceptibility to cardiotoxicity and exacerbates changes in iron metabolism induced by doxorubicin
Authors: Miranda Carlos J. , Makui Hortence , Soares Ricardo J. , Bilodeau Marc , Mui Jeannie , Vali Hajatollah , Bertrand Richard , Andrews Nancy C. , Santos Manuela M.
Published: June 2003

The clinical use of doxorubicin (DOX), an anthracycline chemotherapeutic agent, is limited by cardiotoxicity. The possible involvement of iron in DOX-induced cardiotoxicity became evident from studies in which iron chelators were shown to be cardioprotective. Iron overload is found in hereditary hemochromatosis, a genetic disorder prevalent in individuals of European descent. We hypothesized that Hfe deficiency may increase susceptibility to DOX-induced toxicity. Acute cardiotoxicity and iron changes were studied after treatment with DOX in Hfe knock-out (Hfe-/-) mice and wild-type mice. DOX-induced iron metabolism changes were intensified in Hfe-/- mice, which accumulated significantly more iron in the heart, liver, and pancreas, but less in the spleen compared with wild-type mice. In addition, Hfe-deficient mice exhibited significantly greater sensitivity to DOX-induced elevations in serum creatine kinase and aspartate aminotransferase. Increased mortality after chronic DOX treatment was observed in Hfe-/- mice and Hfe+/-mice compared with wild-type mice. DOX-treated Hfe-/- mice had a higher degree of mitochondrial damage and iron deposits in the heart than did wild-type mice. These data demonstrate that Hfe deficiency in mice increases susceptibility to DOX-induced cardiotoxicity and suggest that genetic mutations related to defects in iron metabolism may contribute to its cardiotoxicity in humans. (Blood. 2003;102:2574-2580)
Persistent Mycobacterium avium infection following nonmyeloablative allogeneic peripheral blood stem cell transplantation for interferon-γ receptor-1 deficiency
Authors: Horwitz Mitchell E. , Uzel Gulbu , Linton Gilda F. , Miller Judi A. , Brown Margaret R. , Malech Harry L. , Holland Steven M.
Published: June 2003

Interferon-γ receptor-1 (IFNγR1) deficiency is a rare inherited immunodeficiency. We performed a nonmyeloablative allogeneic stem cell transplantation on a boy with complete IFNγR1 deficiency and refractory disseminated Myco-bacterium avium infection. Despite the patient's profound immune defect, early donor stem cell engraftment was low. Full donor engraftment was accomplished only following multiple donor lymphocyte infusions. Detection of IFNγR1 expression on peripheral blood monocytes and neutrophils corresponded with establishment of stable, complete donor hematopoietic chimerism. However, expression of, and signaling through IFNγR1 disappeared shortly thereafter. Disseminated Mycobacterium avium infection persisted and the patient died. Coculture of Myco-bacterium avium with normal myeloid cells resulted in an IFNγ signaling defect similar to that observed in vivo. Active disseminated Mycobacterium avium infection may significantly compromise normal immune reconstitution following allogeneic stem cell transplantation. Patients with IFNγR1 deficiency should receive transplants before developing refractory mycobacterial infections. (Blood. 2003;102:2692-2694)
Resolution and outcome of acute circulatory failure does not correlate with hemodynamics
Authors: Suistomaa Matti , Uusaro Ari , Parviainen Ilkka , Ruokonen Esko
Published: June 2003

Introduction

Hemodynamic goals in the treatment of acute circulatory failure (ACF) are controversial. In critical care, organ failures can be assessed using Sequential Organ Failure Assessment and its refinement, total maximal Sequential Organ Failure Assessment (TMS). We studied the associations between resolution of ACF and hemodynamics in the early (< 24 hours) phase of intensive care unit care and their relation to TMS and mortality.

Patients and methods

Eighty-three patients with ACF (defined as arterial lactate > 2 mmol/l and/or base deficit > 4) who had pulmonary artery catheters and stayed for longer than 24 hours in the intensive care unit were included. Hemodynamics, oxygen transport, vasoactive drugs and TMS scores were recorded. Normalisation of hyperlactatemia and metabolic acidosis in less than 24 hours after admission was defined as a positive response to hemodynamic resuscitation.

Results

Fifty-two patients responded to resuscitation. Nonresponders had higher mortality than responders (52% versus 33%, P = 0.044). Hospital mortality was highest (63%) among nonresponders who received vasoactive drugs. The TMS scores of nonresponders (median [interquartile range], 12 [9–16]) were higher than the scores of responders (10 [7–12], P = 0.019). Late accumulation of TMS scores was associated with increasing mortality, and if the TMS score increase occurred > 5 days after admission then the mortality was 77%. Responders had higher mean arterial pressure at 24 hours, but it was no different between survivors and nonsurvivors. No other hemodynamic and oxygen transport variables were associated with the success of resuscitation or with mortality.

Conclusions

Except for the mean arterial pressure at 24 hours, invasively derived hemodynamic and oxygen transport variables are not associated with the response to resuscitation or with mortality. Positive response to resuscitation in ACF is associated with less severe organ failures as judged by TMS scores. Late accumulation of the TMS score predicts poor outcome.
Integrity in the Care of Elderly People, as Narrated by Female Physicians
Authors: Nordam Ann , Sørlie Venke , Förde R
Published: June 2003

Three female physicians were interviewed as part of a comprehensive investigation into the narratives of female and male physicians and nurses, concerning their experience of being in ethically difficult care situations in the care of elderly people. The interviewees expressed great concern for the low status of care for elderly people, and the need to fight for the specialty and for the care and rights of their patients. All the interviewees’ narratives concerned problems relating to perspectives of both action ethics and relational ethics. The main focus was on problems concerning the latter perspective, expressed as profound concern and respect for the individual patient. Secondary emphasis was placed on relationships with relatives and other professionals. The most common themes in an action ethics perspective were too little treatment and the lack of health services for older patients, together with overtreatment and death with dignity. These results were discussed in the light of Løgstrup’s ethics, which emphasize that human life means expressing oneself, in the expectation of being met by others. Both Ricoeur’s concept of an ethics of memory and Aristotle’s virtue ethics are presented in the discussion of too little and too much treatment.
The Impact of Conflict and War on International Nursing and Ethics
Authors: Tschudin Verena , Schmitz Christine
Published: June 2003

Modern nursing evolved out of a war. Today’s nurses not only work in war zones but the profession as a whole needs to consider its responsibility in caring for victims of conflict and what its international duty is in preventing wars. This means that nurses must be informed of the devastation caused by conflict not only in countries where conflicts and war take place but also world-wide. Nurses’ responsibility is to prevent illness and alleviate suffering, which includes the long-term morbidity caused by wars. They need to be more politically active in conflict resolution and prevention at local, community, national and international levels. The purpose of this article is to address these issues from an ethical perspective and to suggest implications for nursing education and practice.
Storied Ethics: conversations in nursing care
Authors: Skott Carola
Published: June 2003

The purpose of this article is to discuss narration of ethical themes in nursing care. The text represents part of the findings of an ethnographic study aimed at description of everyday work on an oncology ward. Nurses on this ward are constantly involved in ethical care issues and narratives are told to share experiences. Of vital importance in ethical decision making is the perpetual creation of a mediating moral world constituted by daily experience. The need for making space in nursing for a continual learning conversation is expressed and in this I include writings of nursing theorists.
Nurses and the Virtues of Dealing with Existential Questions in Terminal Palliative Care
Authors: Houtepen Rob , Hendrikx David
Published: June 2003

We have conducted a small qualitative empirical study into the problems that nurses encounter in delivering existential support in their care of dying patients. We found that nurses are confronted with four types of problem: determining whether the patient actually has put a genuine question for existential support on the agenda; assessing what the import of such a question is; devising an adequate procedure for offering existential support; and organizing adequate support for themselves. Our analysis shows that it takes a ‘fine-tuned antenna’ from nurses to determine these existential questions, which are often put indirectly and in a variety of forms. We have attempted to show that the subtleties of the communicative dimension of palliative terminal care require an intricate set of virtues on the part of the nurse. We have analysed these virtues in a bottom-up approach, inferring them directly from the material obtained from interviews. The framework utilized is the Aristotelian one of striking the right balance between the poles of a morally relevant dimension.
A Pilot Study of Selected Japanese Nurses’ Ideas on Patient Advocacy
Authors: Davis Anne J , Konishi Emiko , Tashiro Marie
Published: June 2003

This pilot study had two purposes: (1) to review recent Japanese nursing literature on nursing advocacy; and (2) to obtain data from nurses on advocacy. For the second purpose, 24 nurses at a nursing college in Japan responded to a questionnaire. The concept of advocacy, taken from the West, has become an ethical ideal for Japanese nurses but one that they do not always understand, or, if they do, they find it difficult to fulfil. They cite nursing leadership support as necessary to enacting this role. Discussion on the meaning of and the rationale for advocacy in a society where goodness or badness is relative to social situations and its impact may reveal two parallel but overlapping views of morality. Such a situation would not only influence notions of advocacy but also possibly render them more complex.
Hungary’s ‘Black Angel’ and Her ‘Dragons’
Authors: Rozsos Elizabeth
Published: June 2003

Nurse Timea Faludi was taken into custody in Hungary in 2001, after confessing to administering lethal doses of drugs to seriously ill elderly patients between May 2000 and February 2001. On 2 December 2002, the Court of First Instance found the nurse guilty on several counts of attempted homicide and of wilfully endangering four persons’ lives in her professional capacity. This article discusses unethical and illegal acts in Hungary.
The Ethics of Developed Nations Recruiting Nurses from Developing Countries: The Case of Malawi
Authors: Muula Adamson S , Mfutso-Bengo Joseph M , Makoza Joan , Chatipwa Elita
Published: June 2003

There is currently a global shortage of nurses. Developing countries such as Malawi are among those hardest hit by this shortage. The demands on available nurses have increased and at the same time there is a lack of interest in becoming a nurse owing to the poor working conditions among those still employed in the service. It is questionable if developed nations should recruit nurses from countries such as Malawi, where severe human resource constraints are being experienced. We argue in this article that the current phenomenon of nurses leaving developing nations for western countries is complex. Human rights issues of individual autonomy and public interest are at stake.
Adjuvant High-Dose Bolus Interleukin-2 for Patients With High-Risk Renal Cell Carcinoma: A Cytokine Working Group Randomized Trial
Authors: Clark Joseph I. , Atkins Michael B. , Urba Walter J. , Creech Steven , Figlin Robert A. , Dutcher Janice P. , Flaherty Larry , Sosman Jeffrey A. , Logan Theodore F. , White Richard , Weiss Geoffrey R. , Redman Bruce G. , Tretter Christopher P.G. , McDermott David , Smith John W. , Gordon Michael S. , Margolin Kim A.
Published: June 2003

Purpose: This prospective, randomized, controlled phase III trial assessed high-dose bolus interleukin-2 (IL-2) postoperatively in patients with high-risk renal cell carcinoma (RCC).

Patients and Methods: Eligibility requirements were resected locally advanced (LA; T3b-4 or N1–3) or metastatic (M1) RCC, no prior systemic therapy, and excellent organ function. Randomized assignment was to one course of IL-2 (600,000 U/kg every 8 hours on days 1 to 5 and days 15 to 19 [maximum 28 doses]) or observation. The study was designed and powered to show an improvement in predicted 2-year disease-free survival (DFS) from 40% for the observation group to 70% for the treatment group. The accrual goal was 68 patients with LA disease, with 34 patients per treatment arm. Metastasectomy patients were to be analyzed separately because of their unpredictable natural history.

Results: Sixty-nine patients were enrolled onto the study (44 LA and 25 M1 patients). Toxic effects of IL-2 were as anticipated; no unexpected serious adverse events or treatment-related deaths occurred. Early closure occurred when an interim analysis determined that the 30% improvement in 2-year DFS could not be achieved despite full accrual. Sixteen of 21 LA patients receiving IL-2 experienced relapse, compared with 15 of 23 patients in the observation arm (P = .73); in the LA group, three deaths occurred in the IL-2 arm, and five deaths occurred in the observation arm (P = .38). Analysis including metastasectomy patients made no difference in DFS or overall survival.

Conclusion: One course of high-dose bolus IL-2, though feasible, did not produce the ambitious clinically meaningful benefit anticipated when administered postoperatively to patients with resected high-risk RCC.
Phase I Clinical Trial of Weekly Combretastatin A4 Phosphate: Clinical and Pharmacokinetic Results
Authors: Rustin Gordon J.S. , Galbraith Susan M. , Anderson Helen , Stratford Michael , Folkes Lisa K. , Sena Luiza , Gumbrell Lindsey , Price Patricia M.
Published: June 2003

Purpose: A phase I trial was performed with combretastatin A4 phosphate (CA4P), a novel tubulin-binding agent that has been shown to rapidly reduce blood flow in animal tumors.

Patients and Methods: The drug was delivered by a 10-minute weekly infusion for 3 weeks followed by a week gap, with intrapatient dose escalation. Dose escalation was accomplished by doubling until grade 2 toxicity was seen. The starting dose was 5 mg/m2.

Results: Thirty-four patients received 167 infusions. CA4P was rapidly converted to the active combretastatin A4 (CA4), which was further metabolized to the glucuronide. CA4 area under the curve (AUC) increased from 0.169 at 5 mg/m2 to 3.29 μmol • h/L at 114 mg/m2. The mean CA4 AUC in eight patients at 68 mg/m2 was 2.33 μmol • h/L compared with 5.8 μmol • h/L at 25 mg/kg (the lowest effective dose) in the mouse. The only toxicity that possibly was related to the drug dose up to 40 mg/m2 was tumor pain. Dose-limiting toxicity was reversible ataxia at 114 mg/m2, vasovagal syncope and motor neuropathy at 88 mg/m2, and fatal ischemia in previously irradiated bowel at 52 mg/m2. Other drug-related grade 2 or higher toxicities seen in more than one patient were pain, lymphopenia, fatigue, anemia, diarrhea, hypertension, hypotension, vomiting, visual disturbance, and dyspnea. One patient at 68 mg/m2 had improvement in liver metastases of adrenocortical carcinoma.

Conclusion: CA4P was well tolerated in 14 of 16 patients at 52 or 68 mg/m2; these are doses at which tumor blood flow reduction has been recorded.
Assessment of Pharmacodynamic Vascular Response in a Phase I Trial of Combretastatin A4 Phosphate
Authors: Anderson Helen L. , Yap Jeffrey T. , Miller Mathew P. , Robbins Adele , Jones Terry , Price Patricia M.
Published: June 2003

Purpose: Clinical evaluation of novel agents that target tumor blood vessels requires pharmacodynamic end points that measure vascular damage. Positron emission tomography (PET) was used to measure the effects of the vascular targeting agent combretastatin A4 phosphate (CA4P) on tumor and normal tissue perfusion and blood volume.

Patients and Methods: Patients with advanced solid tumors were enrolled onto part of a phase I, accelerated-titration, dose-escalation study. The effects of 5 to 114 mg/m2 CA4P on tumor, spleen, and kidney were investigated. Tissue perfusion was measured using oxygen-15 (15O)–labeled water and blood volume was measured using 15O-labeled carbon monoxide (C15O). Scans were performed immediately before, and 30 minutes and 24 hours after the first infusion of each dose level of CA4P. All statistical tests were two sided.

Results: PET data were obtained for 13 patients with intrapatient dose escalation. Significant dose-dependent reductions were seen in tumor perfusion 30 minutes after CA4P administration (mean change, −49% at ≥ 52 mg/m2; P = .0010). Significant reductions were also seen in tumor blood volume (mean change, −15% at ≥ 52 mg/m2; P = .0070). Although by 24 hours there was tumor vascular recovery, for doses ≥ 52 mg/m2 the reduction in perfusion remained significant (P = .013). Thirty minutes after CA4P administration borderline significant changes were seen in spleen perfusion (mean change, −35%; P = .018), spleen blood volume (mean change, −18%; P = .022), kidney perfusion (mean change, −6%; P = .026), and kidney blood volume (mean change, −6%; P = .014). No significant changes were seen at 24 hours in spleen or kidney.

Conclusion: CA4P produces rapid changes in the vasculature of human tumors that can be assessed using PET measurements of tumor perfusion.
Combretastatin A4 Phosphate Has Tumor Antivascular Activity in Rat and Man as Demonstrated by Dynamic Magnetic Resonance Imaging
Authors: Galbraith Susan M. , Maxwell Ross J. , Lodge Martin A. , Tozer Gillian M. , Wilson John , Taylor N. Jane , Stirling J. James , Sena Luiza , Padhani Anwar R. , Rustin Gordon J.S.
Published: June 2003

Purpose: Combretastatin A4 phosphate (CA4P) is a novel vascular targeting agent. Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) studies were performed to examine changes in parameters related to blood flow and vascular permeability in tumor and normal tissue after CA4P treatment.

Materials and Methods: Changes in kinetic DCE-MRI parameters (transfer constant [Ktrans] and area under contrast medium-time curve [AUC]) over 24 hours after treatment with CA4P were measured in 18 patients in a phase I trial and compared with those obtained in the rat P22 carcinosarcoma model, using the same imaging technique. Rats were treated with 30 mg/kg of CA4P; patients received escalating doses from 5 to 114 mg/m2.

Results: A similar pattern and time course of change in tumor and normal tissue parameters was seen in rats and humans. Rat tumor Ktrans was reduced by 64% 6 hours after treatment with CA4P (30 mg/kg). No significant reductions in kidney or muscle parameters were seen. Significant reductions were seen in tumor Ktrans in six of 16 patients treated at ≥ 52 mg/m2, with a significant group mean reduction of 37% and 29% at 4 and 24 hours, respectively, after treatment. The mean reduction in tumor initial area under the gadolinium–diethylenetriamine pentaacetic acid concentration-time curve (AUC) was 33% and 18%, respectively, at these times. No reduction was seen in muscle Ktrans or in kidney AUC in group analysis of the clinical data.

Conclusion: CA4P acutely reduces Ktrans in human as well as rat tumors at well-tolerated doses, with no significant changes in kidney or muscle, providing proof of principle that this drug has tumor antivascular activity in rats and humans.
Phase III Trial of Paclitaxel at Two Dose Levels, the Higher Dose Accompanied by Filgrastim at Two Dose Levels in Platinum-Pretreated Epithelial Ovarian Cancer: An Intergroup Study
Authors: Omura George A. , Brady Mark F. , Look Katherine Y. , Averette Hervy E. , Delmore James E. , Long Harry J. , Wadler Scott , Spiegel Gregory , Arbuck Susan G.
Published: June 2003

Purpose: To determine if increasing the dose of paclitaxel increases the probability of clinical response, progression-free survival, or overall survival in women who have persistent or recurrent ovarian cancer, and whether doubling the dose of prophylactic filgrastim accompanying the higher paclitaxel dose decreases the frequency of neutropenic fever.

Patients and Methods: Consenting patients with persistent, recurrent, or progressing ovarian cancer, despite first-line platinum therapy (but no prior taxane), were randomly assigned to paclitaxel 135 mg/m2, 175 mg/m2, or 250 mg/m2 over 24 hours every 3 weeks. Patients receiving paclitaxel 250 mg/m2 were also randomly assigned to 5 or 10 μg/kg of filgrastim per day subcutaneously.

Results: Accession to the paclitaxel 135-mg/m2 arm was closed early. Among the 271 patients on the other regimens with measurable disease, partial and complete response on paclitaxel 250 mg/m2 (36%) was significantly higher than on 175 mg/m2 (27%, P = .027). This difference was more evident among patients who never responded to prior platinum. However, progression-free and overall survival results were similar. The median durations of overall survival were 13.1 and 12.3 months for paclitaxel 175 mg/m2 and 250 mg/m2, respectively. Thrombocytopenia, neuropathy, and myalgia were greater with paclitaxel 250 mg/m2 (P < .05). The incidence of neutropenic fever after the first cycle of paclitaxel 250 mg/m2 was 19% and 18% on the 5-μg/kg and 10-μg/kg filgrastim dose, respectively (22% for paclitaxel 175 mg/m2 without filgrastim).

Conclusion: Paclitaxel exhibits a dose effect with regard to response rate, but there is more toxicity and no survival benefit to justify paclitaxel 250 mg/m2 plus filgrastim. Doubling the filgrastim dose from 5 to 10 μg/kg did not reduce the probability of neutropenic fever after high-dose paclitaxel.
Effects of Chronic Ethanol on Hepatic and Renal CYP2C11 in the Male Rat: Interactions with the Janus-Kinase 2-Signal Transducer and Activators of Transcription Proteins 5b Pathway
Authors: Badger T. M. , Ronis M. J. J. , Frank S. J. , Chen Y. , He L.
Published: June 2003

Chronic alcohol intake in male rats results in: 1) demasculinization of the GH pulse pattern; 2) reduced serum testosterone concentrations; and 3) decreased expression hepatic CYP2C11. Hepatic CYP2C11 expression is regulated by the male pattern of GH through the Janus-kinase/signal transducer and activators of transcription proteins (JAK/STAT) signal transduction pathway in the male rat. Renal CYP2C11 is regulated by testosterone, not GH. The involvement of the JAK/STAT5b signal transduction pathway in renal CYP2C11 signaling has not been studied. We tested the hypothesis that ethanol reduces CYP2C11 levels by interfering with the JAK/STAT5b pathway. Using a total enteral nutrition (TEN) model to feed rats a well-balanced diet, we have studied the effects of chronic ethanol intake (21 d) on hepatic and renal JAK/STAT pathway of adult male rats (8–10/group). We found decreased hepatic and renal expression of CYP2C11 in ethanol-fed rats with concomitant decreases in STAT5b and phospho-STAT5b, decreased in vitro hepatic STAT5b binding to a CYP2C11 promoter element and no effects on hepatic GHR levels. Ethanol caused tissue specific effects in phospho-JAK2 and JAK2, with increased levels in the liver, but decreased JAK2 expression in the kidney. We conclude that ethanol suppression of CYP2C11 expression is clearly associated with reductions in STAT5b levels, but not necessarily in reductions of JAK2 levels. The mechanisms underlying ethanol-induced suppression of STAT5b is yet to be determined, as is the question of whether this is secondary to hormonal effects or a direct ethanol effect.
Obese Zucker Rats Have Reduced Mineralocorticoid Receptor and 11β-Hydroxysteroid Dehydrogenase Type 1 Expression in Hippocampus—Implications for Dysregulation of the Hypothalamic-Pituitary-Adrenal Axis in Obesity
Authors: Mattsson Cecilia , Lai Maggie , Noble June , McKinney Eoin , Yau Joyce L. , Seckl Jonathan R. , Walker Brian R.
Published: June 2003

Obese Zucker rats have elevated basal corticosterone levels and an increased stress response suggestive of an increased activity of the hypothalamic-pituitary-adrenal (HPA) axis. We hypothesized that altered central expression of glucocorticoid receptors (GR), mineralocorticoid receptors (MR), and/or 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1) contribute to these changes.

In brains from young adult male rats, in situ hybridization and Western blotting showed that obese rats had normal hippocampal GR mRNA and protein levels. In contrast, in obese rats, 11βHSD1 mRNA levels were reduced in a subpopulation of hippocampal cells in the main neuronal layers (by 37–47%, P < 0.05), whereas 11βHSD1 levels in sparse high-expressing cells did not differ. MR mRNA was decreased in all regions of the hippocampus (by 37–49%, P < 0.05 for CA1–2 and P < 0.01 for dentate gyrus) and in frontal cortex (by 16%, P < 0.05) in obese rats. In whole hippocampal homogenates, however, neither the protein concentration of MR by Western blot nor activity of 11βHSD1 was measurably different between the phenotypes. To test the functional importance of lower central MR expression, groups of lean and obese rats were given spironolactone before restraint stress. In vehicle-treated animals, obese rats had higher plasma corticosterone levels than lean rats after stress (by ANOVA, P < 0.05). Spironolactone markedly increased the corticosterone response in both groups, but the incremental rise was smaller in the obese rats, so that spironolactone abolished the differences between groups.

We conclude that lower levels of MR, but not GR, contribute to the increased HPA activity in the obese Zucker rats and that this seems more influential during stress than in the basal state. This may be exacerbated by impaired local regeneration of corticosterone by 11βHSD1. These abnormalities could contribute to the subtle changes in the HPA axis in rodent and human obesity.
Brain Region-Specific Neuroprotective Action and Signaling of Corticotropin-Releasing Hormone in Primary Neurons
Authors: Bayatti Nadhim , Zschocke Jürgen , Behl Christian
Published: June 2003

CRH regulates the body’s response to stressful stimuli by modulating the activity of the hypothalamic pituitary axis. In primary cultures and cell lines, CRH also acts as a potent neuroprotective factor in response to a number of toxins. Using primary neuronal cultures from the cerebellum, cerebral cortex, and hippocampus, we demonstrate that CRH exerts a brain region-specific neuroprotective effect on amyloid β 25–35 toxicity. At low CRH concentrations (10−8m), neuroprotective effects can be observed only in cerebellar and hippocampal cultures, but a higher CRH concentration (10−7m) additionally led to the protection of cortical neurons. These neuroprotective effects were inhibited by H89, a specific protein kinase A inhibitor. Western blot analysis, carried out using phospho-specific antibodies directed against MAPK, cAMP response element-binding protein (CREB), and glycogen synthase kinase (GSK)3β also resulted in brain legion-specific differences regarding intracellular signaling. Correlating with cell survival, low CRH concentrations resulted in activation of the CREB pathway and inactivation of GSK3β in cerebellar and hippocampal cultures, but higher concentrations additionally resulted in activated CREB and inactivated GSK3β in cortical cultures. In contrast, MAPK activation occurred only in cortical neurons. Differences in signaling were found to be independent of receptor expression levels because RT-PCR analysis indicated no region-specific differences in CRHR1 mRNA expression.
Modulation by Steroid Receptor Coactivator-1 of Target-Tissue Responsiveness in Resistance to Thyroid Hormone
Authors: Kamiya Yuji , Zhang Xiao-Yong , Ying Hao , Kato Yusuhito , Willingham Mark C. , Xu Jianming , O’Malley Bert W. , Cheng Sheue-Yann
Published: June 2003

Mutations in the thyroid hormone receptor-β gene (TRβ) cause resistance to thyroid hormone. How the action of mutant thyroid hormone nuclear receptors (TRs) is regulated in vivo is not clear. We examined the effect of a TR coactivator, steroid receptor coactivator-1 (SRC-1), on target-tissue responsiveness by using a mouse model of resistance to thyroid hormone, TRβPV knockin mice, in the SRC-1 null background. Lack of SRC-1 intensified the dysfunction of the pituitary-thyroid axis and impaired growth in TRβPV/+ mice but not in TRβPV/PV mice. In TRβPV/PV mice, however, lack of SRC-1 intensified the pathological progression of thyroid follicular cells to papillary hyperplasia, reminiscent of papillary neoplasia. In contrast, lack of SRC-1 did not affect responsiveness in the liver in regulating serum cholesterol in either TRβPV/+ or TRβPV/PV mice. Lack of SRC-1 led to changes in the abnormal expression patterns of several T3 target genes in the pituitary and liver. Thus, the present studies show that a coactivator such as SRC-1 could modulate the in vivo action of TRβ mutants in a tissue-dependent manner.
Minireview: From Anorexia to Obesity—The Yin and Yang of Body Weight Control
Authors: Zigman Jeffrey M. , Elmquist Joel K.
Published: June 2003

Over the past decade, there has been a tremendous increase in the understanding of the molecular and neural mechanisms that control food intake and body weight. Yet eating disorders and cachexia are still common, and obesity cases are rising at alarming rates. Thus, despite recent progress, an increased understanding of the molecular and neural substrates that control body weight homeostasis is a major public health goal. In this review, we discuss the mechanisms by which metabolic signals interact with key behavioral, neuroendocrine, and autonomic regulatory regions of the central nervous system. Additionally, we offer a model in which hormones such as leptin and ghrelin interact with similar central nervous system circuits and engage them in such a way as to maintain an appropriate and tight regulation of body weight and food intake. Our model predicts that overstimulation or understimulation of these central pathways can result in obesity, anorexia, or cachexia.
Monosodium Glutamate-Sensitive Hypothalamic Neurons Contribute to the Control of Bone Mass
Authors: Elefteriou Florent , Takeda Shu , Liu Xiuyun , Armstrong Dawna , Karsenty Gerard
Published: June 2003

Using chemical lesioning we previously identified hypothalamic neurons that are required for leptin antiosteogenic function. In the course of these studies we observed that destruction of neurons sensitive to monosodium glutamate (MSG) in arcuate nuclei did not affect bone mass. However MSG treatment leads to hypogonadism, a condition inducing bone loss. Therefore the normal bone mass of MSG-treated mice suggested that MSG-sensitive neurons may be implicated in the control of bone mass. To test this hypothesis we assessed bone resorption and bone formation parameters in MSG-treated mice. We show here that MSG-treated mice display the expected increase in bone resorption and that their normal bone mass is due to a concomitant increase in bone formation. Correction of MSG-induced hypogonadism by physiological doses of estradiol corrected the abnormal bone resorptive activity in MSG-treated mice and uncovered their high bone mass phenotype. Because neuropeptide Y (NPY) is highly expressed in MSG-sensitive neurons we tested whether NPY regulates bone formation. Surprisingly, NPY-deficient mice had a normal bone mass. This study reveals that distinct populations of hypothalamic neurons are involved in the control of bone mass and demonstrates that MSG-sensitive neurons control bone formation in a leptin-independent manner. It also indicates that NPY deficiency does not affect bone mass.
Minireview: Human Obesity—Lessons from Monogenic Disorders
Authors: O’Rahilly Stephen , Farooqi I. Sadaf , Yeo Giles S. H. , Challis Benjamin G.
Published: June 2003

Genetic influences on the determination of human fat mass are profound and powerful, a statement that does not conflict with the obvious influence of environmental factors that drive recent changes in the prevalence of obesity. The assertion of the importance of genetic factors has, until recently, largely been based on twin and adoption studies. However, in the last 6 yr, a number of human genes have been identified in which major missense or nonsense mutations are sufficient in themselves to result in severe early-onset obesity, usually associated with disruption of normal appetite control mechanisms. Progress in the identification of more common, subtler genetic variants that influence fat mass in larger numbers of people has been slower, but discernible. Human genetics will continue to make an invaluable contribution to the study of human obesity by identifying critical molecular components of the human energy balance regulatory systems, pointing the way toward more targeted and effective therapies and assisting the prediction of individual responses to environmental manipulations.
Minireview: The Adipocyte—At the Crossroads of Energy Homeostasis, Inflammation, and Atherosclerosis
Authors: Rajala Michael W. , Scherer Philipp E.
Published: June 2003

Adipose tissue evolved to efficiently store energy for times of caloric restriction. The large caloric excess common in many Western diets has negated the need for this thrifty function, leaving adipose tissue ill-equipped to handle this increased load. An excess of adipose tissue increases risk for a number of conditions including coronary artery disease, hypertension, dyslipidemias, type 2 diabetes, and even cancer. Indeed, the ability of the adipocyte to function properly when engorged with lipid can lead to lipid accumulation in other tissues, reducing their ability to function and respond normally. The role of adipose tissue as an endocrine organ capable of secreting a number of adipose tissue-specific or enriched hormones, known as adipokines, is gaining appreciation. The normal balance of these adipose tissue secretory proteins is perturbed in obesity. Paradoxically, the lack of normal adipose tissue, as seen in cases of lipodystrophy and lipoatrophy, is also associated with pathologic sequelae similar to what is seen with obesity. The pathologic findings associated with lack of adipose tissue, largely due to inability to properly store lipids, may also be due to a lack of adipokines. In this review, we highlight the role of adipose tissue as an endocrine organ focusing on some of the recent advances in the identification and pharmacological characterization of adipokines as well as their regulation in the context of obesity and insulin-resistant states.