bluuebunny/crossref_metadata_2025 huggingface dataset:
Engineering responsiveness to cell culture stresses: Growth arrest and DNA damage gene 153 (GADD153) and the unfolded protein response (UPR) in NS0 myeloma cells
Authors: Cudna Renata E. , Dickson Alan J.
Published: March 2006

The successful movement of a newly synthesized protein through the endoplasmic reticulum (ER) and associated membranous compartments is dependent on appropriate recognition by complex processing systems. Failure to perceive appropriately processed or modified intermediates in the pathway can initiate a series of cellular signaling events (ER stress or unfolded protein response, UPR) that can lead to cell apoptosis and loss of biomass in culture processes. We have shown that expression of growth arrest and DNA damage gene 153 (GADD153) is associated with recognition of damaged or mis‐processed proteins within the secretory processes of CHO and NS0 myeloma cells. To directly characterize the roles of GADD153 in UPR‐directed apoptosis, we have generated stable clones of NS0 myeloma cells with elevated (constitutive and inducible) and deleted GADD153 expression. Although GADD153 is a robust indicator of the onset of ER stress or the UPR, GADD153 expression alone is not sufficient to provoke NS0 myeloma apoptosis and it is not required for apoptosis to occur. © 2006 Wiley Periodicals, Inc.
Malachite green‐conjugated microtubules as mobile bioprobes selective for malachite green aptamers with capturing/releasing ability
Authors: Hirabayashi Miki , Taira Shu , Kobayashi Suzuko , Konishi Kaoru , Katoh Kaoru , Hiratsuka Yuichi , Kodaka Masato , Uyeda Taro Q.P. , Yumoto Noboru , Kubo Tai
Published: March 2006

We have developed a novel mobile bioprobe using a conjugate of a kinesin‐driven microtubule (MT) and malachite green (MG) as a platform for capturing MG RNA aptamers. The fluorescence of MG increases when it is bound to an MG aptamer, allowing MT–MG conjugates to work as sensors of RNA transcripts containing the MG aptamer sequence. Kinesin motor proteins provide an effective driving force to create mobile bioprobes without any manipulation. Although the fluorescence of a small number of MG‐binding aptamers is low, the self‐organization of tubulins into MTs enables the microscopic observation of the bound aptamers by collecting them on MTs. We demonstrate that MT–MG conjugates can select target aptamers from a transcription mixture and transport them without losing their inherent motility. Because the MG aptamer binds MG in a reversible manner, MT–MG conjugates can conditionally load and unload the target aptamers. This is one advantage of this system over the molecular probes developed previously in which reversible unloading is impossible due to high‐affinity binding, such as between avidin and biotin. Furthermore, an MT–MG conjugate can be used as a platform for other MG aptameric sensors with recognition regions for various target analytes optimized by further selection procedures. This is the first step to applying living systems to in vitro devices. This technique could provide a new paradigm of mobile bioprobes establishing high‐throughput in vitro selection systems using microfluidic devices operating in parallel. © 2006 Wiley Periodicals, Inc.
Transcriptional profiling of apoptotic pathways in batch and fed‐batch CHO cell cultures
Authors: Wong Danny Chee Furng , Wong Kathy Tin Kam , Lee Yih Yean , Morin Peter Nissom , Heng Chew Kiat , Yap Miranda Gek Sim
Published: March 2006

Chinese Hamster ovary (CHO) cells are regarded as one of the “work‐horses” for complex biotherapeutics production. In these processes, loss in culture viability occurs primarily via apoptosis, a genetically controlled form of cellular suicide. Using our “in‐house” developed CHO cDNA array and a mouse oligonucleotide array for time profile expression analysis of batch and fed‐batch CHO cell cultures, the genetic circuitry that regulates and executes apoptosis induction were examined. During periods of high viability, most pro‐apoptotic genes were down‐regulated but upon loss in viability, several early pro‐apoptotic signaling genes were up‐regulated. At later stages of viability loss, we detected late pro‐apoptotic effector genes such as caspases and DNases being up‐regulated. This sequential regulation of apoptotic genes showed that DNA microarrays could be used as a tool to study apoptosis. We found that in batch and fed‐batch cultures, apoptosis signaling occurred primarily via death receptor‐ and mitochondria‐mediated signaling pathways rather than endoplasmic reticulum‐mediated signaling. These insights provide a greater understanding of the regulatory circuitry of apoptosis during cell culture and allow for subsequent targeting of relevant apoptosis signaling genes to prolong cell culture. © 2006 Wiley Periodicals, Inc.
Intracellular ATP and total adenylate concentrations are critical predictors of reovirus productivity from Vero cells
Authors: Burgener A. , Coombs K. , Butler M.
Published: March 2006

The productivity of reovirus type‐3 Dearing was studied in cultures of Vero cells in serum‐free media. Viral productivity was dependent upon the metabolic state of the cells rather than the phase of growth at which the cells were infected. Cells at different energy states were established by 24‐h incubation in nutrient‐depleted media. This resulted in variable intracellular nucleotide concentrations but high cellular viability was maintained. Of the nucleotides analyzed at the time of infection only the intracellular [ATP] and total adenylate nucleotides were positively correlated with viral productivity. The correlated data followed a sigmoidal plot with an equation defined by polynomial regression analysis. Apparent threshold values of 3.2 fmol/cell and 3.3 fmol/cell were established for ATP and total adenylate, respectively, at which the viral production was 50% the maximal value. Cultures with lower ATP and total adenylate levels at the time of infection resulted in as much as a 95% reduction in overall viral titer compared to the control. The adenylate energy charge (AEC) showed a negative correlation with viral production with an AEC value >0.97 resulting in low virus productivity. Intracellular ATP or total adenylate concentration at the point of infection may be used as a predictor of viral yield in bioprocesses designed for virus/vaccine production. © 2006 Wiley Periodicals, Inc.
Strategy for selection of methods for separation of bioparticles from particle mixtures
Authors: van Hee P. , Hoeben M.A. , van der Lans R.G.J.M. , van der Wielen L.A.M.
Published: March 2006

The desired product of bioprocesses is often produced in particulate form, either as an inclusion body (IB) or as a crystal. Particle harvesting is then a crucial and attractive form of product recovery. Because the liquid phase often contains other bioparticles, such as cell debris, whole cells, particulate biocatalysts or particulate by‐products, the recovery of product particles is a complex process. In most cases, the particulate product is purified using selective solubilization or extraction. However, if selective particle recovery is possible, the already high purity of the particles makes this downstream process more favorable. This work gives an overview of typical bioparticle mixtures that are encountered in industrial biotechnology and the various driving forces that may be used for particle–particle separation, such as the centrifugal force, the magnetic force, the electric force, and forces related to interfaces. By coupling these driving forces to the resisting forces, the limitations of using these driving forces with respect to particle size are calculated. It shows that centrifugation is not a general solution for particle–particle separation in biotechnology because the particle sizes of product and contaminating particles are often very small, thus, causing their settling velocities to be too low for efficient separation by centrifugation. Examples of such separation problems are the recovery of IBs or virus‐like particles (VLPs) from (microbial) cell debris. In these cases, separation processes that use electrical forces or fluid–fluid interfaces show to have a large potential for particle–particle separation. These methods are not yet commonly applied for large‐scale particle–particle separation in biotechnology and more research is required on the separation techniques and on particle characterization to facilitate successful application of these methods in industry. © 2006 Wiley Periodicals, Inc.
Warum gibt es in der Natur keine Räder? Nur scheinbar ein Paradox
Authors: Meyer Veronika R. , Halbeisen Marcel
Published: March 2006

Räder konnten in der Natur nicht entwickelt werden, weil biologische Gewebe auf die ständige Zufuhr von Nährstoffen und die Abfuhr von Abfällen angewiesen sind. Dadurch wird die kontinuierliche “Reparatur” und folglich eine lange Lebensdauer von Lebewesen ermöglicht. Ein Rad auf einer Achse kann nicht mit einem Transportsystem zu einem Lebewesen verbunden werden, vor allem nicht mit einem Blutkreislauf und mit dem Herzen. Für die Fortbewegung in der Natur sind Räder zudem in den allermeisten Ökosystemen gar nicht brauchbar, es sei denn, die Natur hätte auch noch Straßen ohne Unebenheiten und ohne große Steigungen erfunden.
Die Prinzipien der pflanzlichen Wasserleitung. Nach oben gezogen
Authors: Roth‐Nebelsick Anita
Published: March 2006

Das Holz ist in der Lage, Wasser unter Zugspannung nach oben zu befördern. Da sich in diesem Zustand Embolien einstellen können, die die leitenden Elemente funktionsunfähig machen, muss die Pflanze entsprechende “Vorkehrungen” treffen. Von wesentlicher Bedeutung sind in diesem Zusammenhang die Wurzelpassage des Wassers und die mikroskopische Struktur der Holzzellen, insbesondere die Gestaltung der Tüpfel. Im Laufe der Evolution haben sich unterschiedliche Holzzelltypen entwickelt, die das Holz einer Pflanzenart je nach Umweltbedingungen optimieren. In Bezug auf die Funktion bestimmter Strukturparameter, wie beispielsweise Weite und Länge von Gefäßen, hat man bereits klare Vorstellungen. Der Selektionswert vieler Feinstrukturen des Holzes ist hingegen noch unklar. Mit seinen faszinierenden biophysikalischen Eigenschaften stellt Holz nicht nur unter dem Aspekt seiner Biomechanik, sondern auch aufgrund seiner Fähigkeit zur Wasserleitung eine für die Bionik interessante biologische Struktur dar.
Ökologie von Stauseen. Lebensräume, Organismen, Raum‐Zeit‐Strukturen
Authors: Uhlmann Dietrich , Horn Wolfgang
Published: March 2006

Stauseen sind, obwohl sie künstlich geschaffen wurden, weit mehr als nur halbe Seen. Hinsichtlich ihrer Naturausstattung sind sie Seen nur in Teilen unterlegen. So fehlen aufgrund der häufigen großen Stauspiegelschwankungen die Lebensräume der Uferregion weitgehend. Trotzdem bieten Stauseen eine Fülle von Lebensräumen und besitzen eine große Artenvielfalt. Eigenheiten bestehen auch hinsichtlich des Wasser‐ und Stoffhaushaltes, denn Zuflussmengen und Wasseraustausch sind deutlich größer – mit Vor‐ und Nachteilen: negative Veränderungen im Einzugsgebiet wirken sich schneller auf das Gewässer aus, können aber auch rascher und einfacher “repariert” werden. Die hypolimnische Wasserabgabe ist ein spezieller Vorzug, denn so wird sauerstoffarmes und nährstoffreiches Wasser abgeleitet. Die Barrierewirkung der Stauanlagen hat primär Konsequenzen für die wandernden Organismen. Aber auch die “stationären” Fließgewässerbewohner des nahen Unterlaufes werden neuen Bedingungen ausgesetzt. Große Stauanlagen können sich zudem merklich auf nachfolgende Lebensräume (Auen, Mündungsgebiete) auswirken.
Muschelkrebse als Zeugen der Vergangenheit. Zwischen Biologie, Paläontologie und Umweltforschung
Authors: Frenzel Peter , Matzke‐Karasz Renate , Viehberg Finn A.
Published: March 2006

Ostrakoden sind in aquatischen Habitaten häufig und weit verbreitet. Ihre fossilen Klappen können, wenn sie aus Sedimenten geborgen und untersucht werden, als Archive der Erdgeschichte dienen. Im Quartär werden sie erfolgreich für die Paläomilieuanalyse in der Paläolimnologie, ‐ozeanografie und –klimatologie verwendet. Auch in der Umweltgeologie lassen sie sich für historische und andere Fragestellungen einsetzen.
Brutpflege bei Kalmaren
Authors: Wendler Silke
Published: March 2006

Der Kopffüßer Gonatus onyx mit einer Mantellänge von circa 15 Zentimetern ist einer der häufigsten Kalmare im Pazifik und atlantischen Ozean. Ein Grund für den Erfolg der Art könnte sein, dass die Weibchen Brutpflege betreiben – obwohl dies so gar nicht zum Lebenszyklus der Kalmare passt.
Geografische Verteilung der Hautfarbe
Authors: Kronberg Inge
Published: March 2006

Die Unterschiede in der Hautfarbe sind die offensichtlichsten geografischen Variationen beim Menschen. Die Bewohner am Äquator sind meist dunkler als die der Polarregionen und so vor intensiver Sonneneinstrahlung geschützt. Die Hautpigmentierung wurde zunächst vor allem als Schutz vor Hautkrebs angesehen, obwohl dieser im Allgemeinen erst nach dem reproduktiven Alter auftritt. Nach einer alternativen Hypothese ist die Hautfarbe ein Kompromiss: Sie ist hell genug für die Vitamin‐D‐Synthese, aber dunkel genug, um eine Photolyse von Vitamin B zu verhindern. Durch Migration leben heute nicht alle Menschen in einer Umgebung, an deren UV‐Strahlung sie angepasst sind, einige erhalten mehr, andere weniger Sonne als für ihre Hautfarbe angemessen ist.
npcRNAs: Mehr als nur Überbleibsel einer vergessenen RNA‐Welt
Authors: Brosius Jürgen
Published: March 2006

In den vergangenen Jahren rückte eine Gruppe von Molekülen ins Rampenlicht, die zuvor – im Vergleich zur DNA und den Proteinen – weitgehend vernachlässigt wurde: die so genannten nicht‐proteincodierenden RNAs, also RNA‐Moleküle, die keine Bauanleitung für Proteine enthalten (engl.: “non‐protein‐coding RNA”, abgekürzt npcRNA).
Flexibler Hämtransporter für die Eisenresorption
Authors: Hille‐Rehfeld Annette
Published: March 2006

Eisen wird mitsamt seinem Funktionspartner, der Häm‐Gruppe, aus der Nahrung resorbiert. Jetzt wurde im Dünndarm ein Häm‐Transportprotein identifiziert, dessen Effizienz an den wechselnden Eisenbedarf des Organismus angepasst wird. Dieser Hämtransporter der Wirbeltiere zeigt Verwandtschaft mit einem bakteriellen Tetracyclintransporter.
Estimates of long‐term survival for newly diagnosed cancer patients
Authors: Mariotto Angela B. , Wesley Margaret N. , Cronin Kathleen A. , Johnson Karen A. , Feuer Eric J.
Published: March 2006

BACKGROUND

Patients with newly diagnosed cancer may request an estimate of their prospects for long‐term survival. Unfortunately, standard estimates of survival may be outdated, because they do not reflect recent advances. The authors present a projection method that incorporates trends in survival and provides more up‐to‐date estimates of long‐term survival for newly diagnosed patients.

METHODS

The projection method fits a regression model to interval relative survival and includes a parameter associated with a trend on diagnosis year. The cumulative relative survival rate (CRS) in a target year is calculated by multiplying the projected interval survival rates for that year. To investigate the predictive ability of the projection approach and to develop model‐selection rules, data from the Surveillance, Epidemiology, and End Results Program and the Connecticut tumor registry were used to recreate data that were available at a particular time in the past, and those data were used to project survival for specified target years.

RESULTS

The projection method was better at predicting the survival of recently diagnosed patients than current methods, especially long‐term survival for patients who had disease sites with an increasing and stable trend in survival. The authors predicted that the 15‐year CRS for patients who were diagnosed in 2003 will be 61% for all cancer sites combined, 57% for colorectal cancer, 82% for female breast cancer, 53% for ovarian cancer, and 97% for prostate cancer.

CONCLUSIONS

Although the projection method was more speculative than other methods that are aligned more closely with current observed data, it offered the possibility of providing improved estimates of long‐term survival for recently diagnosed patients. Caution should be used when applying these methods for cancer sites where there has been a dramatic uptake of screening, e.g., prostate cancer, for which the projected results may be overly optimistic. Cancer 2006. Published 2006 by the American Cancer Society.
Nonsmall cell lung cancer presenting with synchronous solitary brain metastasis
Authors: Hu Chaosu , Chang Eric L. , Hassenbusch Samuel J. , Allen Pamela K. , Woo Shiao Y. , Mahajan Anita , Komaki Ritsuko , Liao Zhongxing
Published: March 2006

BACKGROUND

Solitary brain metastases occur in about 50% of patients with brain metastases from nonsmall cell lung cancer (NSCLC). The standard of care is surgical resection of solitary brain metastases, or stereotactic radiosurgery (SRS) plus whole brain radiation therapy (WBRT). However, the optimal treatment for the primary site of newly diagnosed NSCLC with a solitary brain metastasis is not well defined. The goal was to distinguish which patients might benefit from aggressive treatment of their lung primary in patients whose solitary brain metastasis was treated with surgery or SRS.

METHODS

The cases of 84 newly diagnosed NSCLC patients presenting with a solitary brain metastasis and treated from December 1993 through June 2004 were retrospectively reviewed at The University of Texas M. D. Anderson Cancer Center. All patients had undergone either craniotomy (n = 53) or SRS (n = 31) for management of the solitary brain metastasis. Forty‐four patients received treatment of their primary lung cancer using thoracic radiation therapy (median dose 45 Gy; n = 8), chemotherapy (n = 23), or both (n = 13).

RESULTS

The median Karnofsky performance status score was 80 (range, 60‐100). Excluding the presence of the brain metastasis, 12 patients had AJCC Stage I primary cancer, 27 had Stage II disease, and 45 had Stage III disease. The median follow‐up was 9.7 months (range, 1‐86 months). The 1‐, 2‐, 3‐, and 5‐year overall survival rates from time of lung cancer diagnosis were 49.8%, 16.3%, 12.7%, and 7.6%, respectively. The median survival times for patients by thoracic stage (I, II, and III) were 25.6, 9.5, and 9.9 months, respectively (P = .006).

CONCLUSIONS

By applying American Joint Committee on Cancer staging to only the primary site, the thoracic Stage I patients in our study with solitary brain metastases had a more favorable outcome than would be expected and was comparable to Stage I NSCLC without brain metastases. Aggressive treatment to the lung may be justified for newly diagnosed thoracic Stage I NSCLC patients with a solitary brain metastasis, but not for locally advanced NSCLC patients with a solitary brain metastasis. Cancer 2006. © 2006 American Cancer Society.
Breast cancer incidence after the introduction of mammography screening
Authors: Svendsen Anne Louise , Olsen Anne Helene , von Euler‐Chelpin My , Lynge Elsebeth
Published: March 2006

BACKGROUND

A prevalence peak is expected in breast cancer incidence when mammography screening begins, but afterward the incidence still may be elevated compared with prescreening levels. It is important to determine whether this is due to overdiagnosis (ie, the detection of asymptomatic disease that would otherwise not have arisen clinically). In the current study, the authors examined breast cancer incidence after the introduction of mammography screening in Denmark.

METHODS

Denmark has 2 regional screening programs targeting women ages 50 years to 69 years. The programs were initiated in 1991 and 1993, respectively. No screening takes place in the 13 other Danish regions. Data regarding incident breast cancers detected between 1979 and 2001 were retrieved from the Danish Cancer Registry for each screening region and for the rest of Denmark, and time trends in rates for women ages 50 years to 69 years were compared. From 1 program, individual screening data were used to analyze breast cancer incidence in women who were never screened, those who were screened for the first time, or those who previously were screened.

RESULTS

The incidence of breast cancer was found to have increased regardless of screening. In the screening regions, a marked prevalence peak was observed, and the incidence hereafter was compatible with the level indicated by the 95% confidence limits for the regression curves for the rates in the prescreening period, taking into account the artificial ageing in the program, the influx of newcomers, and variations in the data. Women who had undergone previous screening were found to have the same incidence of breast cancer as women who were never screened.

CONCLUSIONS

The data from the current study do not provide evidence of overdiagnosis of invasive breast cancer in the 2 Danish screening programs or, if overdiagnosis was found to occur, it was only of limited magnitude. Cancer 2006. © 2006 American Cancer Society.
Guidelines and selection criteria for secondary cytoreductive surgery in patients with recurrent, platinum‐sensitive epithelial ovarian carcinoma
Authors: Chi Dennis S. , McCaughty Kristina , Diaz John P. , Huh Jae , Schwabenbauer Sarah , Hummer Amanda J. , Venkatraman Ennapadam S. , Aghajanian Carol , Sonoda Yukio , Abu‐Rustum Nadeem R. , Barakat Richard R.
Published: March 2006

BACKGROUND

The benefit of cytoreductive surgery for patients with recurrent epithelial ovarian cancer has not been defined clearly. The objective of this study was to identify prognostic factors for survival in patients who underwent secondary cytoreduction for recurrent, platinum‐sensitive epithelial ovarian cancer and to establish generally applicable guidelines and selection criteria.

METHODS

The authors reviewed all patients who underwent secondary cytoreduction for recurrent epithelial ovarian cancer from 1987 to 2001. Potential prognostic factors were evaluated in univariate and multivariate analyses.

RESULTS

In total, 157 patients underwent secondary cytoreduction, and 153 of those patients were evaluable. After secondary cytoreduction, the median follow‐up was 36.9 months (range, 0.2‐125.6 months), and the median survival was 41.7 months (95% confidence interval, 36.0‐47.2 months). For patients who had a disease‐free interval prior to recurrence of between 6 months and 12 months, the median survival was 30 months compared with 39 months for patients who had a disease‐free interval between 13 months and 30 months and 51 months for patients who had a disease‐free interval >30 months (P= .005). For patients who had a single site of recurrence, the median survival was 60 months compared with 42 months for patients who had multiple sites of recurrence and 28 months for patients who had carcinomatosis (P<.001). The median survival for patients who had residual disease that measured ≤0.5 cm was 56 months compared with 27 months for patients who had residual disease that measured >0.5 cm (P<.001). On multivariate analysis, disease‐free interval (P= .004), the number of recurrence sites (P= .01), and residual disease (P<.001) were significant prognostic factors.

CONCLUSIONS

In the authors' analysis of secondary cytoreduction for recurrent epithelial ovarian cancer, a significant survival benefit was demonstrated for residual disease that measured ≤ 0.5 cm. The disease‐free interval and the number of recurrence sites should be used as selection criteria for offering secondary cytoreduction. Cancer 2006. © 2006 American Cancer Society.
Flow rate calibration. III. The use of stabilized biostandards to calibrate the flow rate and calculate absolute CD4+ T‐cell counts
Authors: Walker Clare L. , Whitby Liam , Granger Viv , Storie Ian , Reilly John T. , Barnett David
Published: March 2006

Background:

We have previously reported a flow rate calibration method for the determination of absolute CD4+ T‐lymphocyte counts that removes the need for the addition of latex beads to each sample. However, a limitation with this approach is that a calibration factor (CF) needs to be applied to adjust for differences in viscosity between latex bead suspensions and biological specimens. We have also demonstrated the value of using stabilized whole blood samples in external quality assessment (EQA) studies; such samples have a stable absolute lymphocyte count for over 1 year, at 4°C. It was successfully demonstrated that this material can be used as a flow rate biocalibration (FRB) material for use as a flow cytometric control to provide a sample with a known CD4+ T‐lymphocyte count. Such material has advantages over latex bead technology as it can act as a full process control as well as having the same matrix and viscosity characteristics as the test material, thus removing the need for a CF.

Methods:

In this study, we have analyzed 268 consecutive normal, abnormal, and HIV+ samples using FRB, incorporating the PanLeucoGating approach and compared this to the MultiSet method, defined as the predicate.

Results:

Percentage similarity statistics revealed the following: 0–3,000 CD4+ cells/μl mean percentage difference (MPD; bias) 1.2%, 95% CI of 5.6–8%; 0–200 CD4+ cells/μl MPD of 1.25%, 95% CI of 11.63–14.13%; 201–500 CD4+ cells/μl MPD of 1%, 95% CI of 4.6–6.6%.

Discussion:

This study demonstrates that stabilized whole blood can be used for FRB. It has the advantage of being a full process control, in addition to costing less than latex beads with highly comparable results. As bench top flow cytometers are extremely stable, this is a low cost and robust alternative to bead based methods for generating absolute CD4 counts. © 2006 International Society for Analytical Cytology
Remission induction chemotherapy induces in vivo caspase‐dependent apoptosis in bone marrow acute myeloid leukemia blast cells and spares lymphocytes
Authors: Vial J.‐P. , Tabrizi R. , Pigneux A. , Lacombe F. , Praloran V. , Belloc F.
Published: March 2006

Background

The goal of new therapeutic strategies is to adapt the treatment of acute myeloid leukemia (AML) patients to the prognostic and/or to the hematological response.

Methods

We analyzed in vivo apoptosis induction in blast cells and in lymphocytes of AML patients receiving remission induction treatment.

Results

We show, on 12 peripheral blood samples, that the increase of peripheral apoptotic blast cells cannot be considered as the earliest marker of the treatment efficiency, because the significant increase of apoptosis followed the white blood cell and the peripheral blast cell count reductions, probably due to an efficient clearance of circulating apoptotic cells. Furthermore, the study of 65 bone marrow samples at d15 showed that the treatment induced apoptosis of blast cells while sparing the lymphocytes. This apoptosis was evidenced both at the caspase and at the membrane levels using respectively fmk‐VAD‐FITC and Annexin V binding assays. We found that less than 50% of apoptosis, measured with the fmk‐VAD‐FITC, in the d15 residual bone marrow blast cells, correlated with lower disease‐free survival probability.

Conclusion

More studies are needed in larger series and earlier during the remission induction treatment to confirm the possible prognostic significance of in vivo apoptosis induction. © 2006 International Society for Analytical Cytology
Flow cytometric features of angioimmunoblastic T‐cell lymphoma
Authors: Chen Weina , Kesler Melissa V. , Karandikar Nitin J. , McKenna Robert W. , Kroft Steven H.
Published: March 2006

Background:

The immunophenotypic features of angioimmunoblastic T‐cell lymphoma (AILT) have not been well described.

Methods:

We retrospectively reviewed our institutional experience with the flow cytometric features of 16 cases of AILT.

Results:

Multiparameter flow cytometry was able to identify a distinct population of immunophenotypically aberrant T cells in 15 of 16 cases. In 13 lymph node specimens, the neoplastic cells ranged from 1.9 to 87% (median 23%) of cells. The ratio of reactive to neoplastic T cells ranged from 0.01 to 20 (median 1.5); reactive T cells outnumbered neoplastic in 9/13 (69%) cases. The neoplastic populations expressed CD2, CD4, CD5, and CD45RO in all cases, lacked expression of CD8 and CD56 in all cases, and showed negative or dim surface CD3 in most cases. CD10 was expressed by the neoplastic populations in 11 of 14 cases at diagnosis; in 3 of these 11 only a subpopulation of the neoplastic cells was CD10(+). CD10 tended to be absent on neoplastic cells in staging bone marrows. The neoplastic population in all but one of the 15 positive cases possessed multiple immunophenotypic abnormalities and these were generally retained during the follow‐up analyses of several cases.

Conclusions:

These results indicate the potential utility of flow cytometry in the diagnosis and follow‐up of AILT. © 2006 International Society for Analytical Cytology
Perceived social support, anxiety, and self‐care among patients receiving hemodialysis
Authors: Mollaoglu Mukadder
Published: March 2006

Background

Hemodialysis therapy requires patients to undergo major lifestyle changes. Patients with increased perceived social support and decreased anxiety are more likely to enhance self‐care.

Patients and Methods

A descriptive‐correlational study design was used to analyze the baseline data of a group of hemodialysis patients (n=140). Three instruments were used: the Exercise of Self‐Care Agency Scale (ESCA), the Hamilton Anxiety Rating Scale (HAM‐A), and the Multidimensional Scale of Perceived Social Support (MSPSS). Descriptive, bivariate, and multivariate analyses were completed.

Results

Social support and anxiety are significant predictors of self‐care after controlling for the effect of time on dialysis. Results indicated that patients who perceived higher levels of social support and lower levels of anxiety were more likely to have a higher level of self‐care.

Conclusions

Interventions to increase hemodialysis patients' perceived social support and decreased anxiety may contribute to an enhanced self‐care ability and positive health outcome, and may subsequently improve self‐care and the psychosocial adjustment to hemodialysis.
CMS proposed revisions to conditions to participation: Part I—patient safety requirements
Authors: Levy Ralph
Published: March 2006

The new conditions to participation are divided into three sets of requirements, relating to (1) patient safety, (2) patient care, and (3) administrative matters. This installment, which is the first of a three‐part series on these proposed requirements, addresses the patient safety requirements. The second and third installments will discuss the patient care and administrative provisions of the proposed regulations.
Relationship between lipoprotein(a), fibrinogen, and fibronectin in non‐diabetic hemodialyzed uremic patients
Authors: Tzanatos Helen A. , Retsa Kalliopi , Soubassi Lygeri , Rizos Dimitris , Skiadas Marios , Bougatsos George , Agroyannis Basil
Published: March 2006

Background

Lipoprotein(a), Lp(a), has been recognized as an atherogenic and thrombogenic lipoprotein in the general population and in hemodialysis (HD) patients. In addition, fibrinogen and fibronectin may promote atherothrombosis. The aim of this study was to investigate any possible relationship between Lp(a) and thrombogenic coagulation proteins in non‐diabetic HD patients.

Patients and Methods

Serum Lp(a) and plasma fibrinogen, plasminogen, and fibronectin levels were measured pre‐HD in 60 uremic patients (30 male, 30 female) aged 58.6±8.0 years who had been receiving HD treatment for 61.3±50.7 months. The control group comprised 20 age‐ and sex‐matched healthy subjects. All patients were receiving erythropoietin treatment.

Results

The mean serum Lp(a) (33.88±34.12 mg/dL) and plasma fibrinogen (329.45±80.62 mg/dL) levels were significantly higher in the HD patients compared with those in the controls (16.70±10.36 and 254.00±43.34 mg/dL, respectively; p<.05 and p<.001, respectively). Plasminogen levels did not differ between the HD patients (11.64±3.22 mg/dL) and the control group (10.67±1.41 mg/dL, p>.05). Fibronectin levels were slightly increased in the HD patients (33.96±5.49 mg/dL) versus in the control group (30.9±5.80 mg/dL, p<.05). There was a significant positive correlation between Lp(a) and fibrinogen levels (r=0.305, p<.02), as well as between Lp(a) and fibronectin levels (r=0.360, p<.01). Moreover, there was a significant positive correlation between fibrinogen and fibronectin levels (r=0.587, p<.0001).

Conclusions

According to our results, in non‐diabetic HD patients, abnormal serum Lp(a) levels significantly correlated with abnormal levels of fibrinogen and fibronectin. There is a concern that the relationship between these atherogenic and thrombogenic acute‐phase proteins may contribute to the increased incidence of atherosclerotic cardiovascular disease in this patient population.
The blind‐spot of regulatory T cells
Authors: Graça Luis , Silva‐Santos Bruno , Coutinho Antonio
Published: March 2006

CD4+CD25+Foxp3+ regulatory T cells (Treg) are natural suppressors of autoimmunity but they can also dampen the effective clearance of infectious organisms. These cells have the potential to be exploited to prevent transplant rejection and to treat autoimmune disease. A paper in this issue of the European Journal of Immunology details a method to selectively expand antigen‐specific Treg from a polyclonal Treg population, by using a specific dendritic cell (DC) subset. Furthermore, the authors show that such Treg can be used to prevent experimental type I diabetes; however, as Treg are positively selected by thymic epithelial cells (TEC) on the basis of self‐reactivity, they would systematically suppress protective immune responses unless their repertoire is devoid of recognition towards peripheral antigen‐presenting cells. This may be achieved by negative selection of developing Treg on thymic DC, thus creating a ‘blind‐spot’ corresponding to DC‐self‐antigens in the mature Treg repertoire. Therefore, therapeutic use of DC subsets for the expansion of rare Treg populations should take into account this blind‐spot, as peptides that are not accessible to thymic DC may be significantly more effective for the expansion of Treg.

See accompanying article http://dx.doi.org/10.1002/eji.200535445
On DNA vaccines and prolonged expression of immunogens
Authors: Hanke Tomáš
Published: March 2006

Persistent hepatitis B virus (HBV) infection represents a major public health concern because of its association with chronic liver disease and the propensity of the disease to progress to cirrhosis and hepatocellular carcinoma. Despite the availability of a prophylactic vaccine effective in a majority of the population, alternative vaccination strategies are being sought to induce protective responses in healthy non‐responders and to boost and broaden T cell responses in chronically infected patients, which may lead to a better control of the virus and/or its eventual complete clearance. In this issue of the European Journal of Immunology immunization of BALB/c mice intramuscularly with a DNA vaccine encoding the hepatitis virus B surface antigen (HBsAg) was shown to result in prolonged secretion of HBsAg into the serum and the elicitation of HBsAg‐specific antibodies. In fact, the vaccine was so efficient that the antibodies and HBsAg formed circulating immune complexes and induced kidney and liver lesions similar to those observed in chronically infected patients. This commentary discusses these results in terms of the safety of plasmid DNA‐vectored genetic vaccines in general, the use of DNA vaccines expressing HBsAg for the treatment of chronic hepatitis and the consequences of prolonged immunogen expression for the development of protective immune responses.

See accompanying article http://dx.doi.org/10.1002/eji.200535468
Rational Synthesis and Characterization of Two Three‐Dimensional Metal‐Organic Frameworks Incorporating Silver Chains and 1,2,3,4,5,6‐Cyclohexanehexacarboxylate
Authors: Wang Jing , Hu Sheng , Tong Ming‐Liang
Published: March 2006

Two new silver polycarboxylate coordination polymers, [Ag3(H3L)(H2O)2]n·2nH2O (1) and [Ag6L(NH3)(H2O)3]n·nH2O (2), have been obtained from the reaction of [Ag(NH3)2](OH) (freshly synthesized from Ag2O and aqueous ammonia) with cis,cis,cis,cis,cis‐1,2,3,4,5,6‐cyclohexanehexacarboxylic acid (H6L) by control of the molar ratio of starting materials. The X‐ray crystal structure analysis reveals that both of them crystallize in the triclinic space group P$\bar {1}$ with a = 6.375(4), b = 9.505(6), c = 15.097(8) Å, α = 93.249(14), β = 100.364(15), γ = 96.453(15)°, V = 891.4(9) Å3, Z = 2 for 1, and a = 8.0380(7), b = 10.1220(9), c = 13.8458(12) Å, α = 76.3450(10), β = 80.9370(10), γ = 68.7230(10)°, V = 1016.83(15) Å3, Z = 2 for 2. Complex 1 features a three‐dimensional (3D) metal‐organic framework (MOF) with one‐dimensional (1D) rectangular channels surrounded by carboxylato‐supported Ag–Ag dimers, Ag–Ag chains, and half deprotonated [H3L]3– ligands. Each [H3L]3– ligand connects eight AgI atoms. The weakly coordinated water ligands and lattice water molecules are located at the channels and form interesting 1D hydrogen‐bonded T4(2)8(2) water tapes with cyclic R86(16) (H2O)8 and R44(8) (H2O)4 units. Complex 2 is also a 3D MOF structure constructed by two types of Ag–Ag chains with Ag8 cluster units and linear Ag4 units, respectively, and fully deprotonated L6– ligands. The silver(I) atoms in 2 exhibit linear, T‐shaped, Y‐shaped, and tetrahedral coordination geometries. Each L6– ligand connects thirteen AgI atoms. The intrachain robust argentophilic interactions play a vital role in the formation of the structure. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Effect of π‐Electron Delocalization on Tautomeric Equilibria – Benzoannulated 2‐Phenacylpyridines
Authors: Gawinecki Ryszard , Kolehmainen Erkki , Loghmani‐Khouzani Hossein , Ośmiałowski Borys , Lovász Tamás , Rosa Pavel
Published: March 2006

Most benzoannulated 2‐methylpyridines react with phenyllithium and substituted alkyl benzoates to give the corresponding 2‐phenacylpyridines. 3‐Methylisoquinoline is transformed into 2‐benzoyl‐3‐methyl‐1‐phenyl‐1,2‐dihydroisoquinoline under these conditions, but replacement of phenyllithium with lithium isopropylcyclohexylamide is effective for production of 3‐phenacylisoquinolines. Except in the cases of some substituted 6‐phenacylphenanthridines, tautomeric mixtures of benzoannulated 2‐phenacylpyridines in chloroform solution always contain the ketimine forms.(Z)‐2‐(2‐Hydroxy‐2‐phenylvinyl)pyridine (enolimine) forms also contribute if the pyridine ring is not benzoannulated or if such annulation is at positions 4,5. On the other hand,(Z)‐2‐benzoylmethylene‐1,2‐dihydropyridine (enaminone) forms exist in equilibrium with the ketimine tautomers if the pyridine ring is benzoannulated at positions 3,4 or 5,6, or at both of these locations. As well as the effectiveness of π‐electron delocalization, other effects, such as the strength of the intramolecular hydrogen bonding, should also be considered in order to infer the tautomeric preferences. Strongly electron‐donating substituents were found to stabilize theketimine forms in each series. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
A conceptual model for meander initiation in bedload‐dominated streams
Authors: Eaton Brett C. , Church Michael , Davies Tim R. H.
Published: March 2006

A simple analytic model is presented relating local sediment transport capacity to variance in the transverse shear stress distribution in a stream channel. The model is used to develop a physically based conceptual model for the initiation of meandering in straight, bedload‐dominated streams as a result of a feedback mechanism. The feedback maximizes the cross‐sectional shear stress variance and – in order to achieve stability – ultimately minimizes the energy slope at repeated locations along the channel, subject to steady‐state mass flux and the stability of the channel boundary. These locations develop into pools in a fully developed meandering channel; they represent attractor states wherein sediment continuity is satisfied using the least possible energy expenditure per unit length of channel. However, since the cross‐sectional geometry of a pool (and the adjacent bar) is asymmetric, these attractor states are only conditionally stable, requiring strong, curvature‐induced secondary circulation to maintain their asymmetry. Between two successive pools, a stream occupies a metastable, higher energy state (corresponding to a riffle) that requires greater energy expenditure per unit length of channel to transport the same volume of sediment. The model we present links processes at the scale of a channel width to adjustments of the channel sinuosity and slope at the scale of a channel reach. We argue that the reach‐scale extremal hypotheses employed by rational regime models are mathematical formalisms that permit a one‐dimensional theory to describe the three‐dimensional dynamics producing stream morphology. Our model is consistent with the results from stream table experiments, with respect to both the rate of development of meandering and the characteristics of the equilibrium channel morphology. Copyright © 2006 John Wiley & Sons, Ltd.
A modular access gateway for managing intermittent connectivity in vehicular communications
Authors: Ott Jörg , Kutscher Dirk
Published: March 2006

The Drive‐thru Internet architecture allows exploiting intermittent connectivity by temporarily connecting to IEEE 802.11 WLAN access points at the roadside from moving vehicles. This poses numerous challenges to a mobile user's equipment: extreme networking characteristics such as short periods of connectivity, unpredictable disconnection times, and vastly varying transmission characteristics. Heterogeneous WLAN hotspot installations may also require different authentication mechanisms and credentials. We have designed a mobile access gateway to deal with these issues on behalf of a user (group) in a moving vehicle and provide usable connectivity for applications without requiring manual operation. The gateway maximises the use of short connectivity periods by detecting network access providing signalling functions for local application processes. It also allows using dedicated radio equipment to prolong connectivity periods. Finally, in selected multi‐user scenarios, further performance improvements are conceivable by sharing (non‐confidential) information across users and applications. Copyright © 2005 AEIT.
Satellite digital multimedia broadcasting—deployment and coverage investigation with radio network planning tool
Authors: Hoppe R. , Wölfle G. , Selier C. , Françon M.‐G. , Aubert P. , Chuberre N.
Published: March 2006

Several technologies for providing mobile broadcast services are currently emerging. Besides terrestrial‐only architectures as DVB‐H, the hybrid satellite & terrestrial system approach of satellite digital multimedia broadcasting (S‐DMB) offers advantages in terms of coverage and cost efficiency. In order to assess the S‐DMB radio coverage in different environments an off‐the‐shelf planning tool for terrestrial radio networks has been adapted to consider satellite transmitters and further extended according to the current specification of the S‐DMB system based on the W‐CDMA air interface. This S‐DMB radio planning tool allows the investigation of the S‐DMB performance in terms of coverage, Eb/Nt and system margin for pure satellite as well as hybrid satellite and terrestrial repeater configurations within various environments (rural, urban and indoor). Such investigations are used to trade the open radio parameters of the S‐DMB system architecture and to gain knowledge concerning the required density of the terrestrial repeaters in order to provide sufficient coverage in urban and indoor environments. Copyright © 2006 AEIT.
Radio network planning of DVB‐H/UMTS hybrid mobile communication networks
Authors: Unger Peter , Kürner Thomas
Published: March 2006

The benefit of hybrid mobile communication networks combining point‐to‐point and point‐to‐multipoint systems should be an optimised transfer of data for both providers and customers. In this paper, the focus is on joint radio network planning of hybrid mobile communication networks consisting of unicast (UMTS) and broadcast (DVB‐H) delivery systems. Optimised network planning is a non‐trivial task even for a single network. Hence, planning and optimisation of hybrid networks implicate great challenges. For these issues, realistic traffic estimations are required. Therefore, a scenario has been developed based on the public reference scenario of Berlin from the IST‐MOMENTUM project. A method for designing a DVB‐H network architecture including transmitter position and cell size is introduced. Furthermore, the necessary transmitting power is estimated. The evaluation of the benefit of a hybrid network is introduced and shown in an example. Copyright © 2006 AEIT.
Performance evaluation of IEEE802.16 WiMax with fixed and mobile subscribers in tight reuse
Authors: Ball C. F. , Humburg E. , Ivanov K. , Treml F.
Published: March 2006

WiMax broadband MAN based on the IEEE 802.16d/e standard supports mobile as well as fixed wireless access services. The underlying subscriber data links are characterised by totally different radio conditions such as propagation, interference rejection capability, terminal antenna gain, pattern and height. This leads to a significant coverage mismatch, different user throughput, system capacity and spectrum efficiency. In this paper, the basic performance of mobile and fixed subscribers has been thoroughly analysed for homogeneous hexagonal 3.5 GHz cellular deployments of an OFDM‐based WiMax system depending on cell size, frequency reuse and offered traffic load. Network level simulation results on user FTP‐application throughput, channel load, modulation and coding scheme utilisation and packet call blocking have been presented for cell radius of 300, 1000 and 2000 m in tight 1 × 1 and 1 × 3 frequency reuse, respectively. The future performance enhancements from optional features as Block Turbo Coding, downlink Power Control, scheduling schemes, sub‐channelling in scalable OFDMA and advanced antenna technology have been evaluated and simulation results provided. Copyright © 2006 AEIT.
Code optimisation for lossless compression of binary memoryless sources based on FEC codes
Authors: Dütsch Nicolas
Published: March 2006

A novel source coding scheme based on turbo codes was recently presented. Lossless data compression is thereby achieved by puncturing data encoded with a turbo code while checking the integrity of the reconstructed information during compression. This paper addresses the generalisation of this compression scheme to iteratively decodable forward error correcting (FEC) codes. Furthermore, an alternative puncturing algorithm is presented which fine‐tunes the compression rate to any desired accuracy. Motivated by an area property which states that the area of the tunnel in the modified extrinsic information transfer (EXIT) chart is proportional to the gap between source coding rate and entropy we apply code optimisation tools to serially concatenated codes in order to minimise the tunnel. Numerical results show that compression rates close to the Shannon limit can be obtained by optimised irregular repeat accumulate codes. Copyright © 2006 AEIT.
From cell capacity to subcarrier allocation in OFDMA
Authors: Pfletschinger Stephan , Ibars Christian
Published: March 2006

In this paper, we show how a fundamental result from information theory can be used to calculate the aggregate channel capacity in the uplink of an access point. The fundamental limits for this cell capacity provide an upper bound for any practically implementable multiple‐access scheme. Based on the famous iterative water‐filling algorithm, we derive an adaptive method for maximising the sum rate in the uplink of a multi‐user OFDM system. This approach results in a surprisingly simple algorithm for the subcarrier allocation in OFDMA. We also evaluate the possible gains that can be obtained by sharing a subcarrier by multiple users and compare its performance to the theoretical limit as well as to a low‐complexity solution. Finally, we show how these methods can be implemented using coded QAM with iterative decoding and we outline how they can be combined with a scheduling strategy. Copyright © 2006 AEIT.