bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure‐function relationship in the AV junction
Authors: Efimov Igor R. , Nikolski Vladimir P. , Rothenberg Florence , Greener Ian D. , Li Jue , Dobrzynski Halina , Boyett Mark
Published: September 2004

In the normal heart, the atrioventricular node (AVN) is part of the sole pathway between the atria and ventricles. Under normal physiological conditions, the AVN controls appropriate frequency‐dependent delay of contractions. The AVN also plays an important role in pathology: it protects ventricles during atrial tachyarrhythmia, and during sinoatrial node failure an AV junctional pacemaker can drive the heart. Finally, the AV junction provides an anatomical substrate for reentry. Using fluorescent imaging with voltage‐sensitive dyes and immunohistochemistry, we have investigated the structure‐function relationship of the AV junction during normal conduction, reentry, and junctional rhythm. We identified molecular and structural heterogeneity that provides a substrate for the dual‐pathway AVN conduction. We observed heterogeneity of expression of three isoforms of connexins: Cx43, Cx45, and Cx40. We identified the site of origin of junctional rhythm at the posterior extension of the AV node in 79% (n = 14) of the studied hearts. This structure was similar to the compact AV node as determined by morphologic and molecular investigations. In particular, both the posterior extension and the compact node express the pacemaking channel HCN4 (responsible for the IF current) and neurofilament 160. In the rabbit heart, AV junction conduction, reentrant arrhythmia, and spontaneous rhythm are governed by heterogeneity of expression of several isoforms of gap junctions and ion channels. Uniform neurofilament expression suggests that AV nodal posterior extensions are an integral part of the cardiac pacemaking and conduction system. On the other hand, differential expression of Cx isoforms in this region provides an explanation of longitudinal dissociation, dual‐pathway electrophysiology, and AV nodal reentrant arrhythmogenesis. © 2004 Wiley‐Liss, Inc.
Cytoarchitecture and intercalated disks of the working myocardium and the conduction system in the mammalian heart
Authors: Shimada Tatsuo , Kawazato Hiroaki , Yasuda Aiko , Ono Noriaki , Sueda Kana
Published: September 2004

Working and specialized cardiac myocytes and their intercalated disks (ID) in the mammalian heart were examined by transmission and scanning electron microscopy. The NaOH/ultrasonication treatment of cardiac tissues resulted in the digestion of collagen fibers and separation of intercellular junctions. Auricular and ventricular myocytes were cylindrical in shape, bifurcated, and connected end‐to‐end at the ID. The ID in the working myocardium showed a stair‐like profile, consisting of steps (plicate segments) and corresponding risers (interplicate segments). The ventricular myocytes had many steps and risers. The steps were filled with numerous finger‐like microprojections, including desmosomes, fasciae adherentes, and small gap junctions. The risers showed the smooth surface, including desmosomes and large gap junctions. The cell strands of the sinoatrial node were oriented linearly, while those of the atrioventricular node formed a reticular network. The ID in both nodal cells was underdeveloped, having few microprojections. Myocytes in the His bundle and its branches were arranged in parallel, and Purkinje cell strands formed reticular networks. The ID in the His‐Purkinje system was irregular in appearance, and the microprojections were larger in size and smaller in number than those of working myocytes. There were few microprojections in the sheep Purkinje cells. The gap junctions in the conduction system were few or small in size in the nodal tissue, but large in the His‐Purkinje system. 2004. © 2004 Wiley‐Liss, Inc.
Conduction abnormality in gap junction protein connexin45‐deficient embryonic stem cell‐derived cardiac myocytes
Authors: Egashira Katsuko , Nishii Kiyomasa , Nakamura Kei‐Ichiro , Kumai Madoka , Morimoto Sachio , Shibata Yosaburo
Published: September 2004

In early‐stage heart, the cardiac impulse does not propagate through the specialized conduction system but spreads from myocyte to myocyte. We hypothesized that the gap junction protein connexin45 (Cx45) regulates early‐stage contractions, because it is the only gap junction protein described in early hearts. Cx45‐deficient (Cx45−/−) mice die of heart failure, concomitantly displaying other complex defects in the cardiovascular system. In order to determine the specific cardiac muscular function of Cx45, we created Cx45−/− embryonic stem (ES) cells to be differentiated into cardiac muscle in vitro. Unlike the coordinated contractions of wild‐type cells, differentiated Cx45−/− cardiac myocytes showed high and irregular pulsation rates. Alterations of the electrophysiological properties of the Cx45−/− cardiac myocytes were indicated both by extracellular recording on planar multielectrode array probes and by intracellular Ca2+ recording of the fluorescent Ca2+ indicator fura‐2. The in vitro system minimizes an influence of hemodynamic factors that complicate the phenotypes of Cx45−/− mice. Our results indicate that Cx45 is an essential connexin for coordinated conduction through early cardiac myocytes. © 2004 Wiley‐Liss, Inc.
Towards a three‐α‐helix bundle protein that binds volatile general anesthetics
Authors: Manderson Gavin A. , Johansson Jonas S.
Published: September 2004

The general anesthetics halothane and chloroform are capable of binding to synthetic water‐soluble four‐α‐helix bundles, which model the putative in vivo receptors. In this study, we investigate the binding of these anesthetics to synthetic water‐soluble three‐α‐helix bundles. A series of variants containing up to four X‐to‐Ala and up to four X‐to‐Met substitutions was made; and the effect of these substitutions on structure, stability and anesthetic binding affinity was examined. Generally, the amount of α‐helix and the stability of the three‐α‐helix bundles decreased as the number of X‐to‐Ala substitutions increased. A concomitant red‐shift in tryptophan fluorescence λmax was seen, suggesting an increased flexibility of the native structure. Up to four X‐to‐Met substitutions had little effect on the amount of α‐helix, but an increase in tryptophan λmax was seen for the variants with three and four methionine substitutions. The exceptions were a) a variant with a clustering of alanine and methionine residues at one end of the three‐α‐helix bundle, suggesting a gate structure that can admit ligand molecules; and b) a variant with a single Leu35Ala substitution, suggesting that at select positions, the size of the side chain is important for defining anesthetic binding affinity. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Effect of chain length on coiled‐coil stability: Decreasing stability with increasing chain length
Authors: Kwok Stanley C. , Hodges Robert S.
Published: September 2004

The de novo design and biophysical characterization of three series of two‐stranded α‐helical coiled coils with different chain lengths are described. Our goal was to examine how increasing chain length would affect protein folding and stability when one or more heptad repeat(s) of K–A–E–A–L–E–G (gabcdef) was inserted into the central region of different coiled‐coil host proteins. This heptad was designed to maintain the continuous 3–4 hydrophobic repeat of the coiled‐coil host and introduce an Ala and Leu residue in the hydrophobic core at the a and d position, respectively, and a pair of stabilizing interchain ionic i to i′ + 5 (g to e′) interactions per heptad inserted. The secondary structures of the three series of disulfide‐bridged polypeptides were studied by CD spectroscopy and their stabilities determined by chemical and thermal denaturation. The results showed that successive insertions of this heptad systematically decreased the stability of all the coiled coils studied regardless of the overall initial stability of the host coiled coil. These observations are in contrast to the generally accepted implication that the folding and stability of coiled coils are enhanced with increasing chain length. Our results imply that, in these examples where an Ala and Leu hydrophobic residue were introduced into the coiled‐coil core per inserted heptad, there was still insufficient stability to overcome unfavorable entropy associated with chain length extension, even though the inserted heptad contained the most stabilizing hydrophobic residue (Leu) at position d and stabilizing ionic attractions. © 2004 Wiley Periodicals, Inc. Bioploymers (Pept Sci), 2004
Influence of conformational flexibility on biological activity in cyclic astin analogues
Authors: Saviano Gabriella , Benedetti Ettore , Cozzolino Rosanna , De Capua Antonia , Laccetti Paolo , Palladino Pasquale , Zanotti Giancarlo , Amodeo Pietro , Tancredi Teodorico , Rossi Filomena
Published: September 2004

The astins, a family of natural antitumor cyclopeptides, from the roots of Aster tataricus, consist of a 16‐membered ring system containing uncoded amino acid residues. The backbone conformation, with a cis‐3,4‐dichlorinated proline residue, plays an important role in antineoplastic activity. The acyclic astins, on the other hand, do not show antitumor activity, suggesting that the cyclic nature of astins may be a key role in their biological properties. Although the antineoplastic activity of natural astins has been screened in vitro and in vivo, the mechanism of action has never been investigated. With the aim at elucidating the influence of conformational flexibility on biological activity, we have designed and synthesized several astin analogues containing either Aib and the nonproteinogenic Abu and (S)β3hPhe residues, able to modify the peptide backbone structure, or the peptide bond surrogate SO2NH. Tested for their antitumor effect, our astin‐related cyclopeptides are able to inhibit the growth of tumor cell lines, while the acyclic astins are inefficacious. The present work reports on the structure–activity study of a selected synthetic cyclotetrapeptide corresponding to the sequence c[ThrAib(S)β3hPheΨ(CH2SO2NH)Abu], synthesized by classical methods and characterized conformationally by two‐dimensional NMR and molecular dynamics analyses. © 2004 Wiley Periodicals, Inc. Biopolymers (Pept Sci), 2004
Host–guest complexation of oxicam NSAIDs with β‐cyclodextrin
Authors: Banerjee Rona , Chakraborty Hirak , Sarkar Munna
Published: September 2004

Spectroscopic and molecular modeling techniques have been employed to study the interaction of the oxicam group of nonsteroidal antiinflammatory drugs (NSAIDs) with a polysaccharide such as β‐cyclodextrin (β‐cd). β‐cd is a good drug delivery system and is known to reduce harmful side effects of these drugs in the gastrointestinal tract and to increase their clinical efficacy. A detailed understanding of such host–guest interaction helps in designing a better drug delivery system coupled with increased therapeutic potential. However, there exists a controversy as to which prototropic form of piroxicam, a drug belonging to the oxicam group, becomes encapsulated in the host and also the stoichiometry of binding. In this study, we have revisited that controversy using steady state fluorescence, absorption, fluorescence anisotropy measurements, and molecular modeling techniques. In addition, we have for the first time studied the interactions of two other oxicam drugs, viz. tenoxicam and meloxicam, with β‐cd in aqueous solution. In all cases the neutral forms of these drugs were incorporated in the β‐cd cavity with a binding stoichiometry of 1:1 host : guest. The values of the binding constants for piroxicam, meloxicam, and tenoxicam with β‐cyclodextrin are 134 ± 21, 114 ± 15, and 115 ± 13 M−1, respectively. Molecular modeling studies show that the minimum energy configuration gives favorable interaction energy between the host and the guest in the complex with 1:1 stoichiometry when the conjugated rings of the drugs are inside the hydrophobic bucket‐like cavity of β‐cd and the third ring is exposed to the solvent. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Geometry drives the “deviated‐bending” of the bi‐tubular structures of the 9+2 axoneme in the flagellum
Authors: Cibert Christian , Heck Jean‐Vivien
Published: September 2004

The axoneme “9+2” is basically a system constituted of a cylinder of 9 microtubule doublets surrounding a central pair of microtubules. These bi‐tubular structures are considered as the support system of the active molecular complexes that generate and regulate the axonemal movement. Schoutens has calculated their moments of inertia [Schoutens, 1994: Journal of Theoretical Biology 171:163–177]. The results obtained allowed us to assume that these bi‐tubular systems are endowed with dynamic properties that could be involved in the regulation of the axonemal machinery. For the first time, using the finite elements methods and the resistance of material principles, we have now calculated that the curvature of the axoneme induces the deviated‐bending of the bi‐tubular structures of the axoneme, because of their geometry only; they behave as beams in a framework. This approach is similar to the one used to measure the deflection of a single microtubule [Kasas et al., 2004: Chem Phys Chem 5:252–257]. These behaviors induce internal movement or constraints of either couples or triplets of doublets within the axonemal cylinder that could be directly involved in a constrained or a spontaneous “convergence/divergence” equilibrium of the cylindrical generatrices that they draw along the axonemal cylinder, which could apparently regulate the activity of the axonemal motors (the dynein arms). These results are discussed here, taking into consideration the dynamic propagation of the wave train along the flagellar axoneme, and the regulated balance between the activities of the two opposite sides of the axoneme during the beat. This study raises a few questions about the architecture‐activity duo of the axonemal doublets. Cell Motil. Cytoskeleton 59:153–168, 2004. © 2004 Wiley‐Liss, Inc.
The clinical value of tumor burden at diagnosis in Hodgkin lymphoma
Authors: Gobbi Paolo G. , Broglia Chiara , Di Giulio Giuseppe , Mantelli Monica , Anselmo Paola , Merli Francesco , Zinzani Pier L. , Rossi Gabriele , Callea Vincenzo , Iannitto Emilio , Paulli Marco , Garioni Lorena , Ascari Edoardo
Published: September 2004

BACKGROUND

The authors investigated the clinical role of tumor burden (TB) in patients with Hodgkin lymphoma, relating this parameter to most of the current clinical and prognostic factors and to the best predictive multifactorial models.

METHODS

The volume of TB at diagnosis was measured directly from the initial staging computed tomography scans in 351 patients who were treated on standard protocols. The mean patient age was 34.0 years ± 16.4 years. Forty‐six patients had clinical Stage I disease, 201 patients had Stage II disease, 64 patients had Stage III disease, and 40 patients had Stage IV disease. There were 146 symptomatic patients. Overall survival (OS), disease‐free survival (DFS), and time to treatment failure (TTF) were the time parameters evaluated in the multivariate analysis. Logistic regression was applied according to those who achieved or failed complete remission.

RESULTS

The mean TB normalized to body surface area (rTB) was 137.8 cm3/m2± 124.7 cm3/m2(range, 1.9–694.5 cm3/m2). In multivariate analysis, rTB was the best predictor of TTF, DFS, and complete remission; the second best predictor of OS after patient age; and largely superior to all prognostic models analyzed. For the same stage and treatment, patients who were destined to clinical failure had an initial rTB 60–108% higher compared with the initial rTB in patients who achieved a cure, whereas differences in drug dose intensity were not significant.

CONCLUSIONS

In the current study, it was found that the rTB, as a prognostic factor, was more effective than and was independent of hitherto used factors and scores. The rTB may be a tool for evaluating the curative potential of treatment combinations, allowing physicians and patients to make better therapeutic choices earlier. Cancer 2004. © 2004 American Cancer Society.
Late‐delayed cerebral involvement in systemic non‐Hodgkin lymphoma
Authors: Lossos Alexander , Ashhab Yaqoub , Sverdlin Elena , Amir Gail , Ben‐Yehuda Dina , Siegal Tali
Published: September 2004

BACKGROUND

Central nervous system involvement is a well recognized complication of systemic non‐Hodgkin lymphoma. Most central nervous system recurrences occur within the first 2 years after the initial diagnosis and are considered to represent clonally related recurrence of systemic disease. The authors attempted to investigate the clonal relation between the late‐delayed central nervous system involvement and the original systemic tumor.

METHODS

The authors studied archival, formalin fixed, paraffin embedded tissue samples from 8 patients with isolated cerebral involvement diagnosed > 3 years after their initial presentation with aggressive, systemic, B‐cell non‐Hodgkin lymphoma. The rearranged immunoglobulin heavy‐chain variable region genes (VH) from both sites were amplified by polymerase chain reaction and were sequenced when necessary.

RESULTS

In three of five patients who had interpretable results, a distinct, monoclonal, VH family‐specific band profile was obtained from the cerebral and systemic lymphoma. In the other two patients, a similar VH band pattern was observed and also was compared using direct sequencing, which demonstrated sequence differences between tumors from the two sites.

CONCLUSIONS

Clonal variance between the cerebral and systemic lymphoma in these patients suggested the possibility that some instances of late‐delayed recurrence in the central nervous system represent a second, new B‐cell lymphoma rather than a true recurrence of the original systemic tumor, a finding that may have significant clinical and biologic implications. Cancer 2004. © 2004 American Cancer Society.
What is ‘insignificant’ prostate carcinoma?
Authors: Klein Eric A.
Published: September 2004

In the absence of clinical context, current definitions of insignificant prostate carcinoma are not useful in assessing the need for definitive treatment. Nonetheless, the findings of Bastian and colleagues, which are reported in the current issue of Cancer, strongly suggest that the Epstein criteria select for a subset of patients who may not require immediate therapy and who, at least initially, may be followed safely. The remaining challenge for the urologic community is to design clinical trials aimed at prospectively identifying individuals who require further intervention and determining when such intervention is necessary. Only after the completion of trials such as these can an accurate definition of ‘insignificant’ prostate carcinoma be put forth.

See pages 2001–5.
Characteristics of insignificant clinical T1c prostate tumors
Authors: Bastian Patrick J. , Mangold Leslie A. , Epstein Jonathan I. , Partin Alan W.
Published: September 2004

BACKGROUND

The authors examined the cases of men who had undergone radical prostatectomy for low‐volume clinical T1c prostate carcinoma that was judged to be ‘insignificant’ on the basis of previously established preoperative clinicopathologic parameters. Pathologic findings subsequently were analyzed for correlations with extent of disease in an attempt to validate the contemporary usefulness of existing parameters for predicting the ‘significance’ of prostate tumors.

METHODS

A series of 237 men who had undergone radical prostatectomy for T1c disease between December 2000 and August 2003 was evaluated. Insignificant prostate carcinoma as assessed on biopsy was defined according to the 1994 Epstein criteria, which were as follows: prostate‐specific antigen density < 0.15 ng/mL, Gleason score ≤ 6, fewer than 3 cores containing prostate carcinoma, and ≤ 50% involvement of any core with prostate carcinoma. Postsurgical pathologic findings were analyzed for potential correlations with the Epstein criteria.

RESULTS

According to the Epstein needle biopsy criteria, organ‐confined prostate carcinoma was detected in 91.6% of all patients, whereas the remaining 8.4% of patients were found to have non‐organ‐confined disease. Comparison of pathologic findings and Epstein biopsy criteria revealed that alteration of the original criteria did not improve the detection of non‐organ‐confined prostate carcinoma.

CONCLUSIONS

The findings made in the current study suggest that the majority of patients with T1c prostate carcinoma have insignificant disease. Furthermore, it was found that the Epstein criteria for identifying insignificant prostate carcinoma remained a useful tool in the making of treatment‐related decisions. Cancer 2004. © 2004 American Cancer Society.
Invasive cutaneous malignant melanoma in Sweden, 1990–1999
Authors: Lindholm Christer , Andersson Ronny , Dufmats Monika , Hansson Johan , Ingvar Christian , Möller Torgil , Sjödin Helena , Stierner Ulrika , Wagenius Gunnar ,   for the Swedish Melanoma Study Group
Published: September 2004

BACKGROUND

The objective of the current study was to compile prospective, population‐based data on cutaneous invasive melanomas in Sweden during the period from 1990 to 1999, to describe and analyze survival data and prognostic factors, and to make comparisons with previously published Swedish and international data.

METHODS

Twelve thousand five hundred thirty‐three patients, which included 97% of all registered melanomas in Sweden, were included and described. Among these, 9515 patients with clinical Stage I and II melanoma were included in an analysis of survival and in a univariate analysis, and 6191 patients were included in a multivariate analysis of prognostic factors.

RESULTS

There was no significant change in melanoma incidence during 1990–1999. Favorable prognostic factors were found, especially in younger and female patients, resulting in a relative 5‐year survival rate of 91.5%. In the multivariate analysis, significant factors that had a negative effect on survival were Clark level of invasion, Breslow thickness, ulceration, older patient age, trunk location, greatest tumor dimension, nodular histogenetic type, and male gender.

CONCLUSIONS

During the period from 1990 to 1999, the 5‐year survival of patients with malignant melanoma in Sweden was better compared with the previously reported rates in published, population‐based studies from Sweden, probably as a result of better secondary prevention due to better knowledge and awareness by both patients and the medical profession. The more favorable prognostic factors and the change in melanoma location found in younger patients, compared with earlier reports, may reflect changes in clothing as well as tanning habits; however, a decrease also was found in Clark Level II and thin melanomas for the same patient group. The authors concluded that further improvements can be achieved with better access to health care and with the use of early melanoma detection campaigns. Cancer 2004. © 2004 American Cancer Society.
Efficacy and feasibility of standard procarbazine, lomustine, and vincristine chemotherapy in anaplastic oligodendroglioma and oligoastrocytoma recurrent after radiotherapy
Authors: Brandes Alba Ariela , Tosoni Alicia , Vastola Francesca , Pasetto Lara Maria , Coria Bartolomea , Danieli Daniela , Iuzzolino Paolo , Gardiman Marina , Talacchi Andrea , Ermani Mario
Published: September 2004

BACKGROUND

To the authors' knowledge, there is a scarcity of accurate data regarding the feasibility of standard chemotherapy with procarbazine, lomustine, and vincristine (PCV) in a homogeneous series of patients with primary anaplastic oligodendroglioma (AO) and oligoastrocytoma (AOA) that was recurrent after surgery and standard radiotherapy. The aim of the current study was to evaluate the overall response rate, toxicity, and time to progression (TTP) with the use of standard PCV in this setting.

METHODS

Between November 1994 and September 2000, 37 patients were enrolled in the current study. Of these, 23 had AO (62%) and 14 had AOA (38%). All patients received standard PCV comprised of lomustine (110 mg/m2) on Day 1, procarbazine (60 mg/m2) on Days 8–21, and vincristine (1.4 mg/m2, maximum total 2 mg) on Days 8 and 29. Cycles were repeated every 6 weeks.

RESULTS

There were 11 complete responses (CR; 29.7%) and 11 partial responses (PR; 29.7%) reported and 8 patients had stable disease (SD; 21.6%). The response rate was higher in patients with AO compared with patients with AOA (77.2% vs. 22.7%;P= 0. 02). The median TTP, which was 12.3 months overall, was 30.3 months in patients who achieved a CR, 19.1 months in patients who achieved a PR, and 6.1 months in patients with SD. The median TTP was 18.6 months in AO patients and 6.14 in AOA patients. There were no cases of severe toxicity reported although in 16 patients (43%) who were free of disease progression, PCV was discontinued because of toxicity or inadequate recovery after 2 weeks of delay.

CONCLUSIONS

PCV chemotherapy was reported to achieved a high response rate and TTP but incurred a high risk of persistent toxicity. Cancer 2004. © 2004 American Cancer Society.
Acute graft‐versus‐host disease: Pathophysiology, clinical manifestations, and management
Authors: Couriel Daniel , Caldera Humberto , Champlin Richard , Komanduri Krishna
Published: September 2004

Hematopoietic stem cell transplantation has evolved as a central treatment modality in the management of different hematologic malignancies. Despite adequate posttransplantation immunosuppressive therapy, acute graft‐versus‐host disease (GVHD) remains a major cause of morbidity and mortality in the hematopoietic stem cell transplantation setting, even in patients who receive human leukemic antigen (HLA) identical sibling grafts. Up to 30% of the recipients of stem cells or bone marrow transplantation from HLA‐identical related donors and most patients who receive cells from other sources (matched‐unrelated, non‐HLA‐identical siblings, cord blood) will develop > Grade 2 acute GVHD despite immunosuppressive prophylaxis. Thus, GVHD continues to be a major limitation to successful hematopoietic stem cell transplantation. In this review, the authors summarize the most current knowledge on the pathophysiology, clinical manifestations, and management of this potentially life‐threatening transplantation complication. Cancer 2004. © 2004 American Cancer Society.
A new model for predicting infectious complications during fludarabine‐based combination chemotherapy among patients with indolent lymphoid malignancies
Authors: Tam Constantine S. , Wolf Max M. , Januszewicz E. Henry , Grigg Andrew P. , Prince H. Miles , Westerman David , Seymour John F.
Published: September 2004

BACKGROUND

Fludarabine‐containing combination chemotherapy regimens are increasingly used in the treatment of indolent lymphoid malignancies, with the associated risk of infection being the major toxicity. Predictors of infection during fludarabine‐containing combination therapy are poorly defined and optimal strategies for infection prophylaxis are not known. The authors analyzed their experience with patients treated with the fludarabine‐mitoxantrone (FM) or fludarabine‐cyclophosphamide (FC) regimens to develop a predictive model for infections.

METHODS

Ninety‐two patients with indolent lymphoid malignancies were treated with FM (n = 29) or FC (n = 63). Baseline variables including age, gender, regimen, disease histology, previous therapy, time from diagnosis to current treatment, performance status, renal function, absolute neutrophil count (ANC), lymphocyte count, and immunoglobulin G levels were examined retrospectively for their association with risk of infectious complications during or within 4 weeks of therapy.

RESULTS

Six risk factors were associated with infectious complications: age > 60 years, ≥ 3 previous therapies, previous fludarabine exposure, time from diagnosis to current treatment of > 3 years, performance status ≥ 2, and baseline ANC < 2.0 × 109/L. Compared with patients with 0–2 risk factors, patients with ≥ 3 risk factors had higher infection rates (26% vs. 7% per cycle, P < 0.0001), more Grade 4 neutropenia (41% vs. 8% per cycle, P < 0.0001), and more neutropenic sepsis (15% vs. 1% per cycle, P < 0.0001).

CONCLUSIONS

Infection risk during fludarabine‐containing combination chemotherapy was predicted with a model comprising six baseline risk factors. Patients predicted to be at high risk of infection were an appropriate group for consideration of prophylactic strategies. Cancer 2004. © 2004 American Cancer Society.
Imatinib mesylate in chordoma
Authors: Casali Paolo G. , Messina Antonella , Stacchiotti Silvia , Tamborini Elena , Crippa Flavio , Gronchi Alessandro , Orlandi Rosaria , Ripamonti Carla , Spreafico Carlo , Bertieri Raffaello , Bertulli Rossella , Colecchia Maurizio , Fumagalli Elena , Greco Angela , Grosso Federica , Olmi Patrizia , Pierotti Marco A. , Pilotti Silvana
Published: September 2004

BACKGROUND

To the authors' knowledge, no effective medical therapy currently is available for advanced chordoma. Imatinib mesylate is a tyrosine kinase inhibitor targeting platelet‐derived growth factor receptor‐β (PDGFRB), BCR‐ABL, and KIT.

METHODS

Six patients with advanced chordoma were treated with imatinib mesylate at a dose of 800 mg daily. In all patients, the tumor was found to be positive for PDGFRB, and in four patients PDGFRB was shown to be phosphorylated/expressed.

RESULTS

After a treatment period of ≥ 1 year, overt tumor liquefaction was evident on computed tomography (CT) scan in the first patient. In previous months, a decrease in contrast enhancement on magnetic resonance imaging (MRI) and a decrease in glucose uptake on positron emission tomography (PET) were detected. Similar signs on MRI and PET were observed in subsequent patients, who had a shorter treatment period. One of these patients initially was removed from therapy and then was readmitted to therapy because of difficulties with regard to tumor response assessment; 1 month after the reinitiation of therapy, an overt decrease in tumor density was visible on CT scan in this patient. In four of five symptomatic patients, a subjective improvement was observed early in the course of treatment. The first patient died after 17 months, with a sizeable, mostly liquefied mass. Another patient died early, apparently of unrelated causes. The remaining patients were on therapy at the time of last follow‐up.

CONCLUSIONS

Imatinib mesylate has been found to have antitumor activity in patients with chordoma. This activity might be mediated by inactivation of PDGFRB. Tumor response manifests through patterns that are similar to those observed in patients with gastrointestinal stromal tumors who respond to molecular‐targeted therapy, but evolves more slowly. The benefit to the patient entailed by this pattern of tumor response in chordoma needs to be elucidated, but may be limited in the presence of significant local disease. Cancer 2004. © 2004 American Cancer Society.
A range of memory possibilities: the challenge of the false memory debate for clinicians and researchers
Authors: Madill Anna , Holch Patricia
Published: September 2004

The aim of this article is to present a succinct review and evaluation of the main areas of contention in the false memory debate and, from this basis, to suggest ways in which the best from both sides can be utilized. We examine the potential pitfalls of therapy in terms of the fallibility and suggestibility of autobiographical memory and therapists and therapeutic techniques as the architects of false memories. We then evaluate the case for false memory formation examining if some researchers hold misconceived views of psychotherapy, if experimental studies lack ecological validity, and the effect of trauma on memory. Finally, we explore how the potential pitfalls of therapy can be avoided in practice, reflecting on the usefulness of British Psychological Society guidelines, how clinicians can implement research findings, and how research on the false memory debate can be improved. We conclude that the way forward is researcher–clinician collaboration in the development of ecologically valid research paradigms. Copyright © 2004 John Wiley & Sons, Ltd.
Tools and tenets of schema therapy: toward the construct validity of the early maladaptive schema questionnaire–research version (EMSQ‐R)
Authors: Cecero John J. , Nelson Joshua D. , Gillie Jacqueline M.
Published: September 2004

This study investigated the scale reliability, factor structure, and convergent validity of the Early Maladaptive Schema Questionnaire–Research Version (EMSQ‐R), a 75‐item self‐report inventory that is a revised version of the Young Schema Questionnaire (YSQ) and that measures the presence and severity of 15 early maladaptive schemas (EMS), in an undergraduate sample of 292 participants. Eleven EMS scales were found to have adequate reliability, and 14 hypothesized EMS factors emerged during factor analysis. In addition, findings provided support for the underlying tenets of Schema Therapy (ST), by demonstrating correlations between EMS and measures of both adult attachment and childhood trauma. Future clinical and research directions are discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Is one assessment enough? Patterns of helping alliance development and outcome
Authors: de Roten Yves , Fischer Mélanie , Drapeau Martin , Beretta Véronique , Kramer Ueli , Favre Nathalie , Despland Jean‐Nicolas
Published: September 2004

Early therapeutic alliance is usually measured by the rating of a single session (between the third and the fifth sessions). However, there is a strong argument in favor of viewing early alliance as a developing process.

This study examined the relationship between patient's rating of the helping alliance (HAq) at each session and therapy outcome. This comparison was repeated using patterns of alliance over the course of treatment. Patterns of therapeutic alliance development were detected by clustering ratings of a sample of N = 70 outpatients across four sessions of very brief psychotherapeutic intervention.

Cluster analysis revealed two main patterns (shapes) of alliance development: (i) stable alliance, and (ii) linear growth pattern. These patterns are more predictive of symptom improvement and social adjustment than single ratings, whereas single ratings measuring the strength of alliance are more correlated with patient's satisfaction. Copyright © 2004 John Wiley & Sons, Ltd.
Both IL‐12 and IL‐18 contribute to small intestinal Th1‐type immunopathology following oral infection with Toxoplasma gondii, but IL‐12 is dominant over IL‐18 in parasite control
Authors: Vossenkämper Anna , Struck Daniela , Alvarado‐Esquivel Cosme , Went Tobias , Takeda Kioyshi , Akira Shizuo , Pfeffer Klaus , Alber Gottfried , Lochner Matthias , Förster Irmgard , Liesenfeld Oliver
Published: September 2004

Oral infection of C57BL/6 mice with Toxoplasma gondii results in small intestinal Th1‐type immunopathology mediated by local production of IFN‐γ, TNF‐α, and NO. To analyze whether the proinflammatory cytokines IL‐12 and IL‐18 play a role in the induction of immunopathology, IL‐12p35/p40–/– and IL‐18–/– mice were orally infected with T. gondii. Wild‐type mice developed massive necrosis in their small intestines and died 7–10 days post infection. Even though IL‐12p35/40–/– mice did not develop the necrosis they all died between day 9 and 11 after infection. In contrast, 50% of IL‐18–/– mice died during the acute phase of infection. Compared to wild‐type mice, IL‐12p35/p40–/– but not IL‐18–/– mice showed significantly higher parasite numbers in their small intestines and significantly higher numbers of parasite‐associated inflammatory foci in their livers. IFN‐γ production was similar in infected wild‐type and IL‐18–/– mice but significantly decreased in IL‐12p35/p40–/– mice. Treatment of mice with anti‐IL‐12‐ or anti‐IL‐18 antibodies after infection prevented the development of intestinal necrosis. These results reveal that both IL‐12 and IL‐18 play an important role in the development of intestinal immunopathology following oral infection with T. gondii. However, IL‐12 is dominant over IL‐18 in the host defense against parasite replication. Therefore, neutralization of IL‐18 (rather than TNF‐α, IL‐12, and IFN‐γ) may be a safe strategy for the treatment of Th1‐associated diseases.
Increased sensitivity of early apoptotic cells to complement‐mediated lysis
Authors: Attali Gitit , Gancz Dana , Fishelson Zvi
Published: September 2004

Opsonization of apoptotic cells with complement proteins contributes to their clearance by phagocytes. Little is known about the lytic effects of complement on apoptotic cells. Sensitivity of cells treated with anti‐Fas antibody (Jurkat cells), staurosporine or etoposide (Raji cells) to lysis by complement was examined. As shown here, early apoptotic cells are more sensitive to lysis by antibody and complement than control cells. More complement C3 and C9 bound to apoptotic than to control cells, even though antibody binding was similar. Enhanced killing and C3/C9 deposition were blocked by benzyloxy‐Val‐Ala‐Asp‐fluoromethylketone, a pan‐caspase inhibitor. Complement‐mediated lysis of early apoptotic cells was also prevented by inhibitors of caspases 6, 8, 9 or 10. In contrast, caspase inhibitors had no effect on the lysis of non‐apoptotic Jurkat and Raji cells. Early apoptotic Jurkat cells were also more sensitive to lysis by the pore formers streptolysin O and melittin. Sensitivity of Jurkat Bcl‐2 transfectants to lysis by complement was analyzed. Enhanced Bcl‐2 expression was associated with reduced C3 deposition and lower sensitivity to complement‐mediated lysis. These results demonstrate that at an early stage in apoptosis, following caspase activation, cells become sensitive to necrotic‐type death by complement and other pore formers. Furthermore, they suggest that Bcl‐2 is actively protecting Jurkat cells from complement‐mediated lysis.
Prevention of diabetes in NOD mice at a late stage by targeting OX40/OX40 ligand interactions
Authors: Pakala Syamasundar V. , Bansal‐Pakala Pratima , Halteman Beth S. , Croft Michael
Published: September 2004

Autoreactive T cells play a major role in the development of insulin‐dependent diabetes mellitus, suggesting that costimulatory molecules that regulate T cell responses might be essential for disease progression. In NOD mice, CD28/B7 and CD40/CD40 ligand (L) interactions control the onset of diabetes from 2 to 4 weeks of age, but blocking these molecules has little effect after this time. Hence, it is possible that other ligand/receptor pairs control a later phase of disease. We now show that OX40 is expressed on CD4 and CD8 T cells several weeks prior to islet destruction, which is initiated around weeks 12–14, and that OX40L is present on dendritic cells in both secondary lymphoid organs and the pancreas from 11 to 13 weeks of age. Blocking OX40L at 6, 9, or 15 weeks after birth had little effect on disease; however, inhibiting OX40/OX40L interactions at week 12, or continuous treatment from week 12 onwards, significantly reduced the incidence of diabetes. Histological examination showed that islet destruction was prevented and insulitis reduced by targeting OX40L. These studies show that OX40/OX40L interactions form a late checkpoint in diabetes development and suggest that these molecules are realistic targets for therapeutic intervention.
Lipopeptide epitopes extended by an Nϵ‐palmitoyl‐lysine moiety increase uptake and maturation of dendritic cells through a Toll‐like receptor‐2 pathway and trigger a Th1‐dependent protective immunity
Authors: Zhu Xiaoming , Ramos Thomas V. , Gras‐Masse Helene , Kaplan Bruce E. , BenMohamed Lbachir
Published: September 2004

Lipopeptides, a form of peptide immunogens, are currently under intense investigation as human vaccines for many infectious pathogens and cancers. However, the cellular and molecular mechanisms of lipopeptide immunogenicity are only partially understood. We have investigated the influence of the lipid content on the immunogenicity of lipopeptides using the herpes simplex virus type 1 (HSV‐1) gD1–23 peptide as a model antigen. Totally synthetic lipopeptides were constructed by covalent attachment to the peptide backbone of either Nϵ‐palmitoyl‐lysine (palmitoyl‐lipidated peptide, palmitoyl‐LP) or cholesterol‐lysine (cholesterol‐lipidated peptide, cholesterol‐LP). Immunization of mice with the palmitoyl‐LP, but not with its cholesterol‐LP analog, induced a strong T cell‐dependent protective immunity against lethal HSV‐1 infection. Analysis of cytokine profiles and IgG2a/IgG1 ratios revealed that a dominant Th1‐type immune response was stimulated by the palmitoyl‐LP, as opposed to a Th2 response generated by its cholesterol‐LP analog. The palmitoyl‐LP was efficiently taken up in vitro by immature dendritic cells (DC) in a time‐ and dose‐dependent manner, and induced phenotypic maturation and production of pro‐inflammatory cytokines by DC. Finally, DC stimulated with the palmitoyl‐LP induced antigen‐specific T cell responses through the Toll‐like receptor‐2 pathway. These findings have important implications for the development of effective lipopeptide immunization strategies against infectious pathogens.
Expression of tissue‐specific autoantigens in the hematopoietic cells leads to activation‐induced cell death of autoreactive T cells in the secondary lymphoid organs
Authors: Zheng Xincheng , Yin Lijie , Liu Yang , Zheng Pan
Published: September 2004

Many tissue‐specific antigens are expressed in specialized cells called peripheral antigen‐expressing cells (PAE) in the thymus and can induce central tolerance. While thymic medullary epithelial cells are the prototypic PAE that express peripheral antigens via an aire‐dependent mechanism, some studies also describe bone marrow (BM)‐derived dendritic cells (DC) and macrophages as PAE in both the thymus and secondary lymphoid organs. However, the role of these cells in development of tolerance to tissue‐specific antigens has not been elucidated. Here we use BM radiation chimeric mice to study the existence of hematopoietic PAE and their contribution to tolerance to tissue‐specific antigens. Our results reveal that BM‐derived PAE exist in both central and secondary lymphoid organs and that the expression of peripheral antigens in the BM‐derived cells does not correlate with aire expression. Using double‐transgenic mice expressing TCR specific for a model antigen expressed under the control of a prostate‐specific promoter, we show that expression of self antigen in PAE of non‐hematopoietic origin is both necessary and sufficient to induce clonal deletion. Surprisingly, while BM‐derived PAE fail to induce clonal deletion, they do cause the activation‐induced cell death of autoreactive cells in the secondary lymphoid organs. Thus, BM‐derived PAE have a distinct function in the maintenance of tolerance to tissue‐specific antigens.
Cross‐reactive recognition of human and primate cytomegalovirus sequences by human CD4 cytotoxic T lymphocytes specific for glycoprotein B and H
Authors: Elkington Rebecca , Shoukry Naglaa H. , Walker Susan , Crough Tania , Fazou Chrysa , Kaur Amitinder , Walker Christopher M. , Khanna Rajiv
Published: September 2004

Although the importance of CD4+ T cell responses to human cytomegalovirus (HCMV) has recently been recognized in transplant and immunosuppressed patients, the precise specificity and nature of this response has remained largely unresolved. In the present study we have isolated CD4+ CTL which recognize epitopes from HCMV glycoproteins gB and gH in association with two different HLA‐DR antigens, DRA1*0101/DRB1*0701 (DR7) and DRA1*0101/DRB1*1101 (DR11). Comparison of amino acid sequences of HCMV isolates revealed that the gB and gH epitope sequences recognized by human CD4+ T cells were not only conserved in clinical isolates from HCMV but also in CMV isolates from higher primates (chimpanzee, rhesus and baboon). Interestingly, these epitope sequences from chimpanzee, rhesus and baboon CMV are efficiently recognized by human CD4+ CTL. More importantly, we show that gB‐specific T cells from humans can also efficiently lyse peptide‐sensitized Patr‐DR7+ cells from chimpanzees. These findings suggest that conserved gB and gH epitopes should be considered while designing a prophylactic vaccine against HCMV. In addition, they also provide a functional basis for the conservation of MHC class II lineages between humans and Old World primates and open the possibility for the use of such primate models in vaccine development against HCMV.
High levels of neutralizing IL‐6 autoantibodies in 0.1% of apparently healthy blood donors
Authors: Galle Pia , Svenson Morten , Bendtzen Klaus , Hansen Morten B.
Published: September 2004

IL‐6‐specific autoantibodies (aAb‐IL‐6) have been reported in diseased and healthy individuals. We recently established a model for aAb‐IL‐6 in different mouse strains, based on vaccination with immunogenic IL‐6 analogues, in which titers of aAb‐IL‐6 above 1,000 resulted in an in vivo IL‐6 deficiency. Here, we examined aAb‐IL‐6 in 4,230 blood donors. Stable low titers of aAb‐IL‐6 were found in 9% of the donors, while 1% had titers ranging from 64 to greater than 10,000. Such aAb‐IL‐6‐positive donors appeared normal with no overt signs of pathology. Natural and recombinant forms of IL‐6 bound avidly to their IgG, and their plasma strongly neutralized IL‐6 in vitro. Slightly elevated concentrations of IL‐6 exclusively in the form of IL‐6‐IgG complexes were present in their circulation. The complexes did not contain soluble IL‐6 receptors. Titers of 0.1% of the blood donors were as positive as the vaccination‐induced IL‐6‐deficient mice. Such donors might be IL‐6 deficient, and if so, IL‐6 seems be dispensable for several months in otherwise healthy individuals. Such highly positive donors also explain why normal human IgG for pharmaceutical use may contain high anti‐IL‐6 activity. Finally, transfusion of plasma with a high titer of aAb‐IL‐6 might, temporally, render a recipient IL‐6 deficient.
The corticosteroid‐induced inhibitory effect on NK cell function reflects down‐regulation and/or dysfunction of triggering receptors involved in natural cytotoxicity
Authors: Vitale Chiara , Chiossone Laura , Cantoni Claudia , Morreale Giuseppe , Cottalasso Francesca , Moretti Sara , Pistorio Angela , Haupt Riccardo , Lanino Edoardo , Dini Giorgio , Moretta Lorenzo , Mingari Maria Cristina
Published: September 2004

Corticosteroids are known to inhibit NK cell functions. However no information is available on whether such inhibition may affect the expression and/or the function of receptors involved in NK cell activation. In an attempt to analyze this point, we studied peripheral blood NK cells isolated from pediatric patients undergoing allogeneic BM transplantation. NK cells were analyzed before, during and after methylprednisolone administration to treat acute graft‐versus‐host disease. In NK cells freshly isolated from peripheral blood during methylprednisolone treatment, the surface expression of activating receptors, particularly NKp46 and NKp30, was consistently reduced. Such impaired expression could also be detected after 5 days of culture in IL‐2. Such cultured NK cells also failed to express the IL‐2‐inducible NKp44 receptor. Accordingly, cytotoxicity against different tumor target cell lines was sharply reduced. The effect on NK cells isolated from healthy individuals and cultured in the presence of methylprednisolone was also analyzed. A similar inhibitory effect occurred in the expression of activating NK receptors. In addition, a sharp impairment of NK cytotoxicity against different tumor target cell lines or immature DC was detected.