bluuebunny/crossref_metadata_2025 huggingface dataset:
CD38 is expressed on human mature monocyte‐derived dendritic cells and is functionally involved in CD83 expression and IL‐12 induction
Authors: Fedele Giorgio , Frasca Loredana , Palazzo Raffaella , Ferrero Enza , Malavasi Fabio , Ausiello Clara Maria
Published: April 2004

Dendritic cell (DC) maturation is characterized by the gain or loss of immunological functions and by expression of distinctive surface receptors. CD38 is an ectoenzyme that catalyzes the synthesis of cyclic ADP ribose (a potent second messenger for Ca2+ release), as well as a receptor that initiates transmembrane signaling upon engagement with its counter‐receptor CD31 or with agonistic monoclonal antibodies. Since CD38 is expressed by resting monocytes, we aimed to monitor CD38 expression during the differentiation of human monocyte‐derived DC (MDDC) and to investigate the possibility that CD38 plays a functional role during DC maturation. CD38 is down‐modulated during differentiation into immature MDDC and expressed again upon maturation. The extent of CD38 expression is dependent on the stimulus adopted (LPS > IFN‐γ > CD40 cross‐linking). Although weak, IFN‐γ consistently induces DC maturation. De novo‐synthesized CD38 is enzymatically active, and its expression in mature (m) MDDC is dependent on NF‐κB activity. However, CD38 is not merely a maturation marker but also mediates signaling in mMDDC, where it maintains its functions as a receptor. Activation via agonistic anti‐CD38 mAb induces up‐regulation of CD83 expression and IL‐12 secretion, whereas disruption of CD38/CD31 interaction inhibits CD83 expression, IL‐12 secretion and MDDC‐induced allogeneic T cell proliferation.
In vivo activation of invariant Vα14 natural killer T cells by α‐galactosylceramide sequentially induces Fas‐dependent and ‐independent cytotoxicity
Authors: Lisbonne Mariette , Hachem Patricia , Tonanny Marie‐Béatrice , Fourneau Jean‐Marie , Sidobre Stephane , Kronenberg Mitchel , Van Endert Peter , Dy Michel , Schneider Elke , Leite‐de‐Moraes Maria C.
Published: April 2004

The present study was designed to clarify the cytotoxic capacities of invariant Vα14 natural killer T (iNKT) cells activated in vivo. We found that as early as 2 h after a single injection of α‐galactosylceramide (α‐GalCer), sorted iNKT splenocytes from treated mice kill Fas‐transfected target cells. The implication of the Fas pathway in this lysis was strengthened by both the blockage of cytotoxicity in the presence of anti‐Fas ligand (FasL) monoclonal antibody (mAb) and the up‐regulation of FasL expression on iNKT cells. Sorted NK cells did not participate inthe lytic activity at this time point. Yet, they became cytotoxic later on, 24 h post‐treatment, when target cell lysis was mainly independent of the Fas pathway. This type of cell killing was predominant at this later time point, even though iNKT cells conserved a slight Fas‐dependent cytotoxicity. NK cells failed to acquire the ability to kill target cells when IFN‐γ production in α‐GalCer‐injected mice was blocked by anti‐IFN‐γ mAb, underscoring the major role of this cytokine. In conclusion, our findings provide the first direct evidence that iNKT cells can exert Fas‐dependent cytotoxicity very shortly after in vivo α‐GalCer activation and later, through IFN‐γ secretion, enable NK cells to kill target cells in a Fas‐independent pathway.
Somatic mutations can lead to a loss of superantigenic and polyreactive binding
Authors: Oppezzo Pablo , Dumas Gérard , Bouvet Jean‐Pierre , Robello Carlos , Cayota Alfonso , Pizarro Juan Carlos , Dighiero Guillaume , Pritsch Otto
Published: April 2004

Although antibodies have been assumed to bind a specific antigen, evidence exists showing that a single antibody can bind to multiple unrelated antigens. We previously studied a human monoclonal antibody expressing a mutated form of the VH3–73 gene and displaying anti‐tubulin activity in a patient suffering from an immunocytic lymphoma. Despite its expression of a VH3 family member, this immunoglobulin failed to react with protein A (SpA), suggesting that somatic mutations could account for its change in specificity. To examine this possibility, we produced recombinant Ig expressing germ‐line (IgMκ‐Germ) or the mutated form (IgMκ‐PER) of the VH3–73 fragment. Comparison of the respective affinities of the two Ig demonstrated that IgMκ‐Germ restores its SpA‐binding capacity, and shows a moderate decrease in its affinity for tubulin. Interestingly, IgMκ‐Germ displayed polyreactive specificity for different autoantigens, which contrasted to the monospecific binding of IgMκ‐PER to tubulin. These results suggest that the monoreactive IgMκ‐PER antibody may be derived from a natural polyreactive antibody through somatic mutation. In addition, both temperature modification and mild denaturation succeeded in recovering the polyreactivity of IgMκ‐PER, which favors the view that conformational modifications of the tertiary structure of antibodies may play a key role in the genesis of polyreactivity.
Direct Electrochemistry of Catalase at a Gold Electrode Modified with Single‐Wall Carbon Nanotubes
Authors: Wang Liang , Wang Jianxiu , Zhou Feimeng
Published: April 2004

The direct electrochemistry of catalase (Ct) was accomplished at a gold electrode modified with single‐wall carbon nanotubes (SWNTs). A pair of well‐defined redox peaks was obtained for Ct with the reduction peak potential at −0.414 V and a peak potential separation of 32 mV at pH 5.9. Both reflectance FT‐IR spectra and the dependence of the reduction peak current on the scan rate revealed that Ct adsorbed onto the SWNT surfaces. The redox wave corresponds to the Fe(III)/Fe(II) redox center of the heme group of the Ct adsorbate. Compared to other types of carbonaceous electrode materials (e.g., graphite and carbon soot), the electron transfer rate of Ct redox reaction was greatly enhanced at the SWNT‐modified electrode. The peak current was found to increase linearly with the Ct concentration in the range of 8×10−6–8×10−5 M used for the electrode preparation and the peak potential was shown to be pH dependent. The catalytic activity of Ct adsorbates at the SWNTs appears to be retained, as the addition of H2O2 produced a characteristic catalytic redox wave. This work demonstrates that direct electrochemistry of redox‐active biomacromolecules such as metalloenzymes can be improved through the use of carbon nanotubes.
Inhibition of solid tumor growth by gene transfer of VEGF receptor‐1 mutants
Authors: Heidenreich Regina , Machein Marcia , Nicolaus Anke , Hilbig Andreas , Wild Carola , Clauss Matthias , Plate Karl H. , Breier Georg
Published: April 2004

Vascular endothelial growth factor (VEGF) and the high‐affinity VEGF receptor Flk‐1/KDR (VEGFR‐2) are key regulators of tumor angiogenesis. Strategies to block VEGF/VEGFR‐2 signaling were successfully used to inhibit experimental tumor growth and indicated that VEGFR‐2 is the main signaling VEGF receptor in proliferating tumor endothelium. Here, we investigated the role of the VEGF receptor‐1 (VEGFR‐1/Flt‐1) in the vascularization of 2 different experimental tumors in vivo. VEGFR‐1 mutants were generated that lack the intracellular tyrosine kinase domain. Retrovirus‐mediated gene transfer of the VEGFR‐1 mutants led to a strong reduction of tumor growth and angiogenesis in xenografted C6 glioma and in syngeneic BFS‐1 fibrosarcoma. Histological analysis of the inhibited fibrosarcoma revealed reduced vascular density, decreased tumor cell proliferation as well as increased tumor cell apoptosis and the formation of necrosis. The retroviral gene transfer of the full length VEGFR‐1 also caused a significant reduction of tumor growth in both models. The inhibitory effects of the VEGFR‐1 mutants and the full length VEGFR‐1 in BFS‐1 fibrosarcoma were mediated through host tumor endothelial cells because the BFS‐1 fibrosarcoma cells were not infected by the retrovirus. The formation of heterodimers between VEGFR‐2 and full length or truncated VEGFR‐1 was observed in vitro and might contribute to the growth inhibitory effect by modulating distinct signal transduction pathways. The results of our study underline the central role of the VEGF/VEGFR‐1 signaling system in tumor angiogenesis and demonstrate that VEGFR‐1 can serve as a target for anti‐angiogenic gene therapy. © 2004 Wiley‐Liss, Inc.
Peptide nucleic acid clamp PCR: A novel K‐ras mutation detection assay for colorectal cancer micrometastases in lymph nodes
Authors: Taback Bret , Bilchik Anton J. , Saha Sukamal , Nakayama Takahiro , Wiese David A. , Turner Roderick R. , Kuo Christine T. , Hoon Dave S. B.
Published: April 2004

Inaccurate staging of colorectal cancer (CRC) has been attributed to the failure to detect lymph node metastases by conventional pathology. We have previously reported the use of lymphatic mapping to accurately identify those lymph nodes most likely to harbor micrometastatic disease and permit focused pathologic examination. Mutation of K‐ras allele at codons 12 or 13 occurs frequently in early stages of CRC development. The purpose of our study was to assess sentinel lymph nodes (SLN) for occult CRC micrometastases using a unique peptide nucleic acid (PNA) clamp PCR assay specific for K‐ras mutations. Seventy‐two paraffin‐embedded primary CRC and paired SLN were evaluated by PNA clamp PCR for K‐ras mutations. Thirty primary tumors (42%) were positive for K‐ras mutations, and in 5 of these cases the SLN were positive for metastases by Hematoxylin and Eosin staining. PNA clamp PCR identified occult metastases in an additional 6 patients, upstaging 24% of K‐ras positive primary CRCs (p = 0.014). No K‐ras mutations were detected among the 20 noncancer lymph nodes assessed. This study demonstrates the utility, specificity and sensitivity of PNA clamp PCR assay in identifying occult micrometastases in the SLN of CRC patients by single‐base mutation analysis. © 2004 Wiley‐Liss, Inc.
Mutation analysis of the RECQL4 gene in sporadic osteosarcomas
Authors: Nishijo Koichi , Nakayama Tomitaka , Aoyama Tomoki , Okamoto Takeshi , Ishibe Tatsuya , Yasura Ko , Shima Yasuko , Shibata Kotaro R. , Tsuboyama Tadao , Nakamura Takashi , Toguchida Junya
Published: April 2004

Osteosarcoma (OS) is the most prevalent malignant tumor among cases of Rothmund‐Thomson syndrome (RTS) with germline mutations of the RECQL4 gene, a member of the RecQ helicase family. We investigated the involvement of the RECQL4 gene in the development of OS unrelated to RTS. RECQL4 mRNA was detected in 9 of 9 OS cell lines by Northern blotting and 26 of 26 OS tumors by RT‐PCR. Direct sequencing of the entire coding region along with flanking splice junctions and 13 small (<100 bp) introns in 71 OS tumors revealed 2 sites with a single‐base change causing an amino acid change (G1814A for R355Q and C2474T for P441S) and one site with a 6 bp inframe deletion (4837‐42delTGCACC for CT857‐8del). Identical genotypes were found in corresponding normal tissues in all cases, and the frequency of each allele was not significantly different between OS and control populations. Our data indicate that the RECQL4 gene is not a frequent target for somatic mutations in sporadic OS unrelated to RTS. © 2004 Wiley‐Liss, Inc.
Beyond the bottom line: Practicing leadership for sustainability
Authors: Quinn Laura , Norton Jane
Published: April 2004

An increasing number of companies are embracing a business philosophy that pays attention not only to financial results but also to environmental and social issues. Such an agenda offers obvious benefits for the world but sizable challenges for leaders—although evidence suggests that their organizations will benefit as well. Here's a primer for leaders on how to approach sustainability.
Stuttering and gait disturbance after supplementary motor area seizure
Authors: Chung Sun J. , Im Joo‐Hyuk , Lee Jae‐Hong , Lee Myoung C.
Published: April 2004

Acquired stuttering is an uncommon speech disorder. Supplementary motor area (SMA) lesions have been reported to be directly or indirectly related to acquired stuttering and various types of motor dysfunction. We report on a patient who presented with both acquired stuttering and long‐lasting gait disturbance after SMA seizure. © 2004 Movement Disorder Society
Persistent abnormal shoulder elevation after accessory nerve injury and differential diagnosis with post‐traumatic focal shoulder‐elevation dystonia: Report of a case and literature review
Authors: Cossu Giovanni , Melis Maurizio , Melis Giannina , Ferrigno Paola , Molari Andrea
Published: April 2004

We report on a patient with persistent abnormal shoulder posture associated with isolated neurogenic hypertrophy of the trapezius muscle due to accessory nerve injury. The patient complained of marked difficulty in shoulder elevation and abduction. Over 6‐month treatment with botulinum toxin, there was a complete resolution © 2004 Movement Disorder Society
Pramipexole‐treated Parkinson's disease during pregnancy
Authors: Mucchiut Marco , Belgrado Enrico , Cutuli Daniela , Antonini Angelo , Bergonzi Paolo
Published: April 2004

There are few reports about drug‐related effects on PD pregnancy. We describe the case of a woman affected by PD treated with pramipexole monotherapy during pregnancy. The child, born by caesarean delivery, is healthy, whereas motor disability of the mother progressively increased to the point that levodopa therapy was necessary. © 2004 Movement Disorder Society
Composite vascularized skin/bone graft model: A viable source for vascularized bone marrow transplantation
Authors: Siemionow Maria , Ulusal Betul G. , Ozmen Selahattin , Ulusal Ali E. , Ozer Kagan
Published: April 2004

In this study, we introduce a new model for vascularized skin and bone marrow transplantation. Twenty‐five Lewis (RT11) rats were studied. Anatomic dissection studies were performed in 5 animals. In the experimental group, 10 isograft transplantations were performed between Lewis rats. Combined groin skin and femoral bone flaps were transplanted based on the femoral artery and vein. Transplants were evaluated on a daily basis. All flaps survived without problems over 100 days posttransplant. The skin component remained pink and pliable, and grew new hair. Histological examination of the femoral bone (except the femoral head) revealed active hematopoiesis with a viable compact and cancellous bone components on day 100 posttransplant. This model can be applied to tolerance induction studies across the major Histocompatibility (MHC) barrier, where bone will serve as donor of stem and progenitor cells, and the skin flap will serve as a monitor of graft rejection. © 2004 Wiley‐Liss, Inc.
Glucose, lactate, and pyruvate response in an experimental model of microvascular flap ischemia and reperfusion: A microdialysis study
Authors: Setälä Leena P. , Korvenoja E. Maj‐lén , Härmä Markku A. , Alhava Esko M. , Uusaro Ari V. , Tenhunen Jyrki J.
Published: April 2004

Early diagnosis of postoperative perfusion failure is essential in microsurgical tissue transfer. In order to determine if microdialysis could be used in diagnosing flap ischemia, we tested this method in an experimental pig model. Sixty‐six flaps (34 myocutaneous and 29 cutaneous) were created in 18 anesthetized pigs. During the experiment, secondary ischemia was induced for 5 h by selective clamping of the artery (20 flaps) or vein (21 flaps). Glucose, lactate, and pyruvate concentrations were measured hourly from the muscular and dermal layers. We found that decreasing glucose levels and increasing lactate concentrations were associated with arterial and venous occlusions from the first hour of ischemia. In venous ischemia, lactate concentrations remained lower than those in arterial ischemia. The increase in lactate‐to‐pyruvate and lactate‐to‐glucose ratios was related to ischemia and also discriminated arterial occlusion from venous occlusion. In conclusion, microdialysis can be used to facilitate early detection of ischemia. © 2004 Wiley‐Liss, Inc.
Gravimetric determination of the diffusion characteristics of polymers using small specimens
Authors: Cervenka A. J. , Young R. J. , Kueseng K.
Published: April 2004

An investigation has been undertaken of the factors controlling the rate of ingress of water into relatively small epoxy specimens. The application of a three‐dimensional diffusion model, fully acknowledging that the specimen geometry controls the rate of ingress, has successfully resolved the problems of determining the diffusion characteristics—the diffusion coefficient D and the uptake M∞ corresponding to saturation—and making theoretical predictions of the uptake Mt by small specimens. On the theoretical front, simulations have been carried out to demonstrate that (1) theoretical predictions require two equations to be used to obtain correct relative uptake Mt/M∞ values for short and long exposure times; (2) a cube of the side h is saturated faster than an infinite slab of the thickness h, and (3) determination of the D value by applying the model derived for an infinite slab to specimens of finite dimensions results in an apparent value that may grossly exceed the true diffusion coefficient. On the experimental front, suggestions are made regarding (4) elimination of a systematic error that might be introduced by single weighing of a specimen prior exposure, (5) determination of the product M∞ D1/2 from the gravimetry data for short exposure times, and (6) splitting this product into absolute values D and M∞ by means of a minimization procedure. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42:2122–2128, 2004
Impact of targeted‐volume ventilation on lung inflammatory response in preterm infants with respiratory distress syndrome (RDS)
Authors: Lista G. , Colnaghi M. , Castoldi F. , Condò V. , Reali R. , Compagnoni G. , Mosca F.
Published: April 2004

Volutrauma and pulmonary inflammation are thought to be the most important predisposing factors of chronic lung disease (CLD), a major complication of prematurity. A new option in patient‐triggered ventilation (PTV), the volume guarantee (VG), a volume‐targeted ventilation, seems to be a promising approach in reducing the risk of CLD, by limiting lung inflammatory injury and volutrauma. Our aim was to evaluate lung inflammatory response in preterm infants with respiratory distress syndrome (RDS), mechanically ventilated with and without VG, as measured by proinflammatory cytokines (IL‐6, IL‐8, and TNF‐α) in tracheobronchial aspirate (TA) fluid. Fifty‐three preterm infants (GA = 25–32 weeks) with RDS were randomized at birth to be ventilated using pressure support ventilation (PSV) with VG (Vt = 5 ml/kg) (n = 30) and without VG (n = 23) (Draeger Babylog 8000 Plus, 5.n). IL‐6, IL‐8, and TNF‐α were determined by ELISA in TA samples on days 1, 3, and 7 of life. We observed a significant difference (ANOVA) in IL‐8 and IL‐6 levels on day 3 between the two groups (P < 0.05), and an increasing significative trend in IL‐8 values in PSV group (P < 0.05). Mechanical ventilation lasted longer in the PSV group (12.3 ± 3 vs. 8.8 ± 3 days) (P = no significance). In conclusion, these preliminary data suggest a role for volume‐targeted ventilatory strategy in reducing acute inflammatory response in preterm infants with RDS. Further studies are required in order to define whether this ventilatory strategy prevents lung injury. Pediatr Pulmonol. 2004; 37:510–514. © 2004 Wiley‐Liss, Inc.
Sex differences among children 2–13 years of age presenting at the emergency department with acute asthma
Authors: Schatz Michael , Clark Sunday , Emond Jennifer A. , Schreiber Donald , Camargo Carlos A.
Published: April 2004

Hospitalization rates for asthma have been reported to be higher in males than females in children under age 15, but it is not clear whether this disparity reflects gender differences in prevalence, severity, or treatment. We performed a prospective cohort study as part of the Emergency Medicine Network. Patients aged 2–13 years who presented to the emergency department (ED) with acute asthma underwent a structured interview in the ED and another by telephone 2 weeks later. Of 1,602 patients, 61% (95% CI, 59–64%) were boys. Girls were slightly older than boys, although no material differences existed in acute presentation, chronic asthma characteristics, ED treatment, or ED course. There was no difference in admission rates for boys or girls (20% vs. 22%; P = 0.48). This finding persisted when adjusting for other factors in a multivariate logistic regression model. No sex differences were observed for relapse or ongoing exacerbation on univariate or multivariate analysis. These data suggest that asthma is not inherently more severe in boys with asthma compared to girls, and that the increased rate of hospitalizations in boys under age 13 is due to differences in prevalence, not severity. Pediatr Pulmonol. 2004; 37:523–529. © 2004 Wiley‐Liss, Inc.
Androgen receptor (AR) expression in AR‐negative prostate cancer cells results in differential effects of DHT and IGF‐I on proliferation and AR activity between localized and metastatic tumors
Authors: Plymate Stephen R. , Tennant Marie K. , Culp Stephen H. , Woodke Lillie , Marcelli Marco , Colman Ilsa , Nelson Peter S. , Carroll Julie M. , Roberts Charles T. , Ware Joy L.
Published: April 2004

Background

Two features of the progression from organ‐confined to metastatic prostate cancer are dysregulation of the androgen receptor (AR) and a decrease in insulin‐like growth factor‐type‐I receptor (IGF‐IR) expression. The purpose of this study was to determine the effect of changes in IGF‐IR expression on AR activity.

Methods

M12 human prostate cells were stably transfected with an AR expression construct to produce the M12‐AR parental (PAR) cell line. PAR cells were implanted orthotopically into nude mice and M12‐AR primary (PRI) cell lines were derived from intraprostatic tumors and metastatic cell lines (MET) were derived from PRI tumors that had metastasized to diaphragm or lung.

Results

Tumor formation in the prostate by PAR cells was decreased significantly compared to M12 controls. PAR, PRI, and MET cells expressed equivalent amounts of AR protein; however, IGF‐IR expression was increased significantly in PAR and PRI cells. IGF‐IR expression decreased in MET lines to the levels seen in M12 control cells. IGF‐I significantly enhanced dihydrotestosterone (DHT)‐stimulated, but not basal, AR transcriptional activity in PRI cells. In MET cells, IGF‐I significantly suppressed DHT‐stimulated transcriptional activity. In MET cells in which the IGF‐IR was re‐expressed from a retroviral vector, the effects of DHT and IGF‐I on AR activity were similar to those seen in PRI cells.

Conclusions

This study demonstrates that the changes in IGF‐IR expression exhibited by this model of metastatic progression cause significant alterations in AR signaling and suggest that this interaction may be an important aspect of the changes seen in AR function in disease progression in vivo. © 2004 Wiley‐Liss, Inc.
Quantitative analysis of eight testosterone metabolites using column switching and liquid chromatography/tandem mass spectrometry
Authors: Magnusson Mats O. , Sandström Rikard
Published: April 2004

The rate at which testosterone is metabolized to different singly hydroxylated metabolites has been widely used as an in vitro marker for activity of different CYP450 enzymes. The interest in extra‐hepatic metabolism, e.g. due to metabolism in the gut wall, has increased during the last decade. Measurement of extra‐hepatic enzyme activity using testosterone as a substrate requires a highly sensitive analytical method. A new liquid chromatography/electrospray tandem mass spectrometry (LC/MS/MS) method, using column switching for online cleaning and desalting of samples, was developed and validated for analysis of 2α‐, 2β‐, 6α‐, 6β‐, 7α‐, 16α‐, and 16β‐hydroxytestosterone and androstenedione. The samples were injected on a SB‐CN column and detection was performed using MS/MS. The limits of quantification ranged from 0.3 to 3.33 nM for the different metabolites. The validated method was used to quantify the enzyme activity in rat intestine mucosa. The formation rates of 16α‐, 16β‐hydroxytestosterone and androstenedione were quantified, and 2β‐and 6β‐hydroxytestosterone were formed above the limits of detection. Copyright © 2004 John Wiley & Sons, Ltd.
Improved sensitivity for insulin in matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry by premixing α‐cyano‐4‐hydroxycinnamic acid matrix with transferrin
Authors: Kobayashi Tetsu , Kawai Hiroshi , Suzuki Takuo , Kawanishi Toru , Hayakawa Takao
Published: April 2004

This report describes an enhancement of the signal intensities of proteins and peptides in matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS). When α‐cyano‐4‐hydroxycinnamic acid (CHCA) premixed with human transferrin (Tf) was used as a matrix, the signal intensity of insulin was amplified to more than ten times that of the respective control in CHCA without Tf. The detection limit of insulin was 0.39 fmol on‐probe in the presence of Tf, while it was 6.3 fmol in the absence of Tf. The signal intensity of insulin was also enhanced when the CHCA matrix was premixed with proteins other than Tf (80 kDa), such as horse ferritin (20 kDa), bovine serum albumin (BSA, 66 kDa), or human immunoglobulin G (150 kDa). The optimum spectrum of insulin was obtained when the added amount of protein was in the range 0.26–0.62 pmol, regardless of the molecular weight of the added protein. Tf and BSA outperformed the other tested proteins, as determined by improvements in the resulting spectra. When the mass spectra of several peptides and proteins were recorded in the presence of Tf or BSA, the signal intensities of large peptides such as glucagon were enhanced, though those of smaller peptides were not enhanced. In addition, the signal enhancement achieved with Tf and BSA was more pronounced for the proteins, including cytochrome C, than for the large peptides. This enhancement effect could be applied to improve the sensitivity of MALDI‐TOFMS to large peptides and proteins. Copyright © 2004 John Wiley & Sons, Ltd.
Logarithmic expected packet delivery delay in mobile ad hoc wireless networks
Authors: del Rio Heberto , Sarkar Dilip
Published: April 2004

It has been shown that in a mobile ad hoc wireless network per node throughput remains constant as the number of nodes approaches infinity, when the nodes lie in a disk of unit area. However, this requires that some packets are delivered indirectly by a relay node. In this paper, we prove, in the same setup, that D(k) ∈ Θ(log k), where D(k) is the expected delay time of a mobile ad hoc wireless network with k nodes. As consequence, we have concluded that mobile ad hoc wireless networks are not scalable for real‐time applications. Copyright © 2004 John Wiley & Sons, Ltd.
Quality of life in schizophrenics with and without the deficit syndrome
Authors: Gourevitch R. , Abbadi S. , Guelfi J.D.
Published: April 2004

We investigated the relations between deficit as part of schizophrenic symptomatology and the popular but unclear concept of quality of life (QOL). In a 47-patient sample, subjective QOL was compared in schizophrenics with and without the deficit syndrome. Self- and hetero-rated QOL is more impaired in deficit patients. Differences between deficit and non-deficit groups are more significant as the index used for measuring QOL gets less “behavioral” and more “psycho-pathological”. These results are consistent with existing literature. The “behavioral” dimensions of Heinrichs’ quality of life scale (QLS) are less discriminative between deficit and non-deficit schizophrenics, but they are more independent of the symptoms. They might have a special clinical meaning, which needs to be defined. The concepts of QOL (as used in QLS) and deficit symptomatology are partially redundant. QLS might be an inappropriate, or at least un-specific measure of QOL.
Human limbal epithelium contains side population cells expressing the ATP‐binding cassette transporter ABCG2
Authors: Watanabe Katsuhiko , Nishida Kohji , Yamato Masayuki , Umemoto Terumasa , Sumide Taizo , Yamamoto Kazuaki , Maeda Naoyuki , Watanabe Hitoshi , Okano Teruo , Tano Yasuo
Published: April 2004

Many types of organ‐specific stem cells have been recently shown to exhibit a side population (SP) phenotype based on their ability to efflux Hoechst 33342 dye. Because stem cells from corneal epithelium reside in the basal layer of the limbal epithelium, the purpose of this study was to examine whether the limbal epithelium contains SP cells. The ATP‐binding cassette transporter Bcrp1/ABCG2 is reported to contribute to the SP phenotype in cells from several diverse sources. Here we show data from fluorescence‐activated cell sorting and real‐time quantitative RT‐PCR analysis showing that harvested limbal epithelial cells contain SP cells expressing ABCG2. Immunofluorescence revealed that a portion of limbal epithelial basal cells expressed ABCG2. Data indicate that ABCG2 positive limbal epithelial cells are putative corneal epithelial stem cells.
Conformational change in substrate binding, catalysis and product release: an open and shut case?
Authors: Gutteridge Alex , Thornton Janet
Published: April 2004

The role of conformational change in substrate binding, catalysis and product release is reviewed for 11 enzymes, for which crystal structures are available for the apo, substrate‐ and product‐bound states. The extent of global conformational changes is measured, and the movements of the functional regions involved in catalysis and ligand binding are compared to the rest of the structure. We find that most of these enzymes undergo relatively small amounts of conformational change and particularly small changes in catalytic residue geometry, usually less than 1 Å. In some enzymes there is significant movement of the binding residues, usually on surface loops.
GENDER DIFFERENCE IN DAILY TIME AND SPACE USE AMONG BANGLADESHI VILLAGERS UNDER ARSENIC HAZARD: APPLICATION OF THE COMPACT SPOT-CHECK METHOD
Authors: OHTSUKA RYUTARO , SUDO NORIKO , SEKIYAMA MAKIKO , WATANABE CHIHO , INAOKA TSUKASA , KADONO TAKAFUMI
Published: April 2004

The compact spot-check method was applied to elucidate the daily time and space use patterns of 121 adults from a Bangladeshi village in which the authors had previously found more skin manifestations due to arsenic poisoning in males than females. The analysis of 2178 spot-check data, which were obtained over a net period of 2 days, highlighted that farming and cash-earning activities were almost exclusively conducted by males. This is probably due to the Muslim Bangladeshi norm for females to be ‘sedentary’ in or around their own dwellings. Discussion focuses on the advantages of the compact spot-check method and the possibility that males’ larger energy expenditure and longer exposure to sunlight are responsible for their severer skin manifestations.
A SOCIAL COMPONENT IN THE NEGATIVE EFFECT OF SONS ON MATERNAL LONGEVITY IN PRE-INDUSTRIAL HUMANS
Authors: VAN DE PUTTE BART , MATTHIJS KOEN , VLIETINCK ROBERT
Published: April 2004

Due to their effect on maternal testosterone levels, sons are said to have reduced maternal longevity in pre-industrial humans. This analysis, using information from a Flemish agricultural village in the 18th–20th centuries, confirms the presence of a negative effect of sons on maternal longevity. However, the effect is mainly observed for mothers belonging to the least privileged social group and for sons surviving their fifth birthday. Both findings make the above-mentioned biological explanation relative. However, a plausible alternative, social interpretation is male-dominated intra-household resource competition. It is reasonable to assume that only sons above a certain age are able to claim a serious amount of resources and that competition is strongest within the least privileged social group.
Two texts in Barzani Jewish Neo-Aramaic
Authors: MUTZAFI HEZY
Published: April 2004

In this article I offer two versions of the Kurdistani folk-tale ‘Khajo and Syabando’ in Barzani Jewish Neo-Aramaic, one of the rarest and most highly endangered modern Aramaic languages, spoken in Israel by no more than twenty elderly Jews from the regions of Barzan and ʕAqra in Iraqi Kurdistan. Three dialects of this language were discovered during the years 1996–2000: Barzan, Shahe and B[ecy ]jil. The latter dialect is already extinct. The narratives that served for the texts were furnished by two speakers of the Barzan dialect. The texts are accompanied by observations related to etymology, comparative dialectology, vocabulary and various aspects of grammar.
Shock pressure induced by 0.44 μm laser radiation on aluminum
targets
Authors: BATANI D. , STABILE H. , RAVASIO A. , DESAI T. , LUCCHINI G. , STRATI F. , ULLSCHMIED J. , KROUSKY E. , SKALA J. , KRALIKOVA B. , PFEIFER M. , KADLEC C. , MOCEK T. , PRÄG A. , NISHIMURA H. , OCHI Y. , KILPIO A. , SHASHKOV E. , STUCHEBRUKHOV I. , VOVCHENKO V. , KRASUYK I.
Published: April 2004

Shock pressure generated in aluminum targets due to the interaction
of 0.44 μm (3 ω of iodine laser) laser radiation has been
studied. The laser intensity profile was smoothed using phase zone
plates. Aluminum step targets were irradiated at an intensity
I ≈ 1014 W/cm2. Shock velocity in
the aluminum target was estimated by detecting the shock luminosity
from the target rear using a streak camera to infer the shock pressure.
Experimental results show a good agreement with the theoretical model
based on the delocalized laser absorption approximation. In the present
report, we explicitly discuss the importance of target thickness on the
shock pressure scaling.
Plasma formation through field ionization in intense
laser–matter interaction
Authors: BAUER D.
Published: April 2004

Optical field ionization is the earliest and fastest
plasma-generating process during the interaction of intense laser light
with matter. By using short and rapidly rising laser pulses, the free
electron density may turn from being transparent for an incoming laser
pulse to reflective in less than half a laser cycle, that is, on a
subfemtosecond timescale. Extremely nonlinear optical effects arise as
a consequence of this. In this article, the basics of optical field
ionization that are relevant in analytical or numerical studies of
intense laser–matter interactions are reviewed. Several
macroscopic effects of field ionization in the interaction of intense
laser pulses with solid targets are briefly surveyed.
X-ray microscopy of living multicellular organisms with the Prague
Asterix Iodine Laser System
Authors: DESAI T. , BATANI D. , BERNARDINELLO A. , POLETTI G. , ORSINI F. , ULLSCHMIED J. , JUHA L. , SKALA J. , KRALIKOVA B. , KROUSKY E. , PFEIFER M. , KADLEC C. , MOCEK T. , PRÄG A. , RENNER O. , COTELLI F. , LAMIA C. LORA , ZULLINI A.
Published: April 2004

Soft X-ray contact microscopy (SXCM) experiments have been performed
using the Prague Asterix Iodine Laser System (PALS). Laser wavelength
and pulse duration were λ = 1.314 μm and τ (FWHM) = 450 ps,
respectively. Pulsed X rays were generated using teflon, gold, and
molybdenum targets with laser intensities I ≥
1014 W/cm2. Experiments have been performed
on the nematodes Caenorhabditis elegans. Images were recorded
on PMMA photo resists and analyzed using an atomic force microscope
operating in contact mode. Our preliminary results indicate the
suitability of the SXCM for multicellular specimens.
Generation of high harmonics in laser plasmas
Authors: FÖLDES I.B. , KOCSIS G. , RÁCZ E. , SZATMÁRI S. , VERES G.
Published: April 2004

The generation of high harmonics in laser–plasma interactions
on the steep density gradients is discussed, especially by using
short-pulse UV laser radiation. Low intensity experiments with
5·1015 W/cm2 generate harmonics in the
VUV range, and the efficiency can be optimized by modifying the density
gradient. To obtain higher harmonics and to clear some disagreements
among different results concerning polarization properties of harmonics
we switched for higher intensities. Our experimental arrangement makes
it possible to obtain a 5·1017 W/cm2
intensity with a prepulse as low as 107 W/cm2
using a table-top system. Preliminary results and future trends for
high-harmonics generation with this method are given.
On the current of an annular electron beam with a virtual cathode
in a drift tube
Authors: BELOMYTTSEV S.YA. , GRISHKOV A.A. , KOROVIN S.D. , RYZHOV V.V.
Published: April 2004

It is shown that beyond a virtual cathode the current of a magnetized
steady-state thin annular electron beam in a drift tube may range from
zero to the limiting current of the tube.
Radiation loss from inertially confined degenerate plasmas
Authors: ELIEZER SHALOM , LEÓN PABLO T. , MARTINEZ-VAL JOSÉ M. , FISHER DIMITRI V.
Published: April 2004

Bremsstrahlung is one of the most important energy loss mechanisms in
achieving ignition, which is only possible above a threshold in
temperature for a given fusion reaction and plasma conditions. A
detailed analysis of the bremsstrahlung process in degenerate plasma
points out that radiation energy loss is much smaller than the value
given by the classical formulation. This fact seems not useful to relax
ignition requirements in self-ignited targets, because it is only
relevant at extremely high densities. On the contrary, it can be very
positive in the fast ignition scheme, where the target is compressed to
very high densities at a minimum temperature, before the igniting
beamlet is sent in.
Equation-of-state studies using a 10-Hz Nd:YAG laser oscillator
Authors: SHUKLA M. , UPADHYAY A. , SENECHA V.K. , KHARE P. , BANDYAOPADHYAY S. , RAI V.N. , NAVATHE C.P. , PANT H.C. , KHAN M. , GODWAL B.K.
Published: April 2004

A commercial mode locked cavity dumped Nd:YAG dye laser operating at
10 Hz repetition rate is modified to produce a high contrast
(>5000:1) single laser pulse while maintaining the energy stability
and high beam quality. A trigger generator biases the cavity dumping
photodiode, which is triggered externally by a pulse from the
microprocessor-based control unit controlling a ∼2 J/200 ps
laser chain. In the laser chain, the high contrast (>5000:1) is
achieved by an external pulse selector based on single Pockel's
cell to select a single laser pulse of high contrast, which is a
prerequisite for experimental study of the equation of state.
Laser-induced shock velocity measurement in thin aluminum, gold on
aluminum, and copper on aluminum foil targets using this modified laser
system are also presented. The equation of state of Al, Au, and Cu
obtained using an impedance matching technique are in agreement with
the reported results of SESAME and simulation results.
High current ion beam RF acceleration and perspectives for an
inertial fusion driver
Authors: RATZINGER U. , LIEBERMANN H. , MEUSEL O. , PODLECH H. , TIEDE R. , BARTH W. , VINZENZ W.
Published: April 2004

The actual situation with respect to the use of an RF linac driver
for heavy ion inertial fusion (HIF) is discussed. At present, there is
no high current heavy ion linac under construction. However, in the
course of linac projects for e−, p, d, or highly
charged ions several developments were made, which may have some impact
on the design of a HIF driver. Medium- and low-β superconducting
structures suited for pulsed high current beam operation are actually
designed and investigated at several laboratories. A superconducting 40
MeV, 125 mA cw linac for deuteron acceleration is designed for the
Inertial Fusion Material Irradiation Facility (IFMIF). The Institute
for Applied Physics (IAP) is developing a superconducting 350-MHz,
19-cell prototype CH-cavity for β = 0.1. The prototype cavity will
be ready for tests in 2004. A superconducting main HIF driver linac
would considerably reduce the power losses. Moreover, it would allow
for an efficient linac operation at a higher duty factor.

The
1.4-AMeV room-temperature High Current Injector HSI at Gesellschaft
für Schwerionenforschung (GSI) has been in routine operation for
more than 2 years now. With a mass-to-charge ratio of up to 65, a
current limit of 15 mA for U4+, and an energy range from 2.2
AkeV up to 1.4 AMeV, this linac is suited to gain useful experience on
the way toward the design of a HIF RF driver. The status and technical
improvements of that A/q ≤ 65, 91-MV linac are reported. Beam
dynamics calculations for Bi1+-beams show that powerful
focusing elements at the linac front end are the bottleneck with
respect to a further increase in beam current. Besides superconducting
and pulsed wire quadrupoles, the potential of the Gabor-plasma lenses
is investigated.
Instantaneous kinematics and singularity analysis of three-legged parallel manipulators
Authors: Dash Anjan Kumar , Chen I-Ming , Yeo Song Huat , Yang Guilin
Published: April 2004

Instantaneous kinematics and singularity analysis of a class of three-legged, 6-DOF parallel manipulators are addressed in this paper. A generic method of derivation of reciprocal screw and consequently, the instantaneous kinematics model is presented. The advantage of this formulation is that the instantaneous kinematics model possesses well-defined geometric meaning and algebraic structure. Singularity analysis is performed under three categories, namely forward, inverse and combined singularities. A new concept of Passive Joint Plane is introduced to correlate the physical structure of the manipulator and these geometric conditions. In the inverse kinematic analysis, a new approach is introduced. At each leg end point a characteristic parallel- epiped is defined whose sides are the linear velocity components from three main joints of the leg. An inverse singularity occurs when the volume of this parallelepiped becomes zero. Examples are demonstrated using RRRS and RPRS-type parallel manipulators.
Sensing characteristics of an optical three-axis tactile sensor under combined
loading
Authors: Ohka Masahiro , Mitsuya Yasunaga , Matsunaga Yasuaki , Takeuchi Shuichi
Published: April 2004

This paper describes precision enhancement of an optical three-axis tactile sensor capable of detecting both normal force and tangential force. The sensor's single cell consists of a columnar feeler and 2-by-2 conical feelers. We have derived equations to precisely estimate the three-axis force from the area-sum and area-difference of the conical feelers' contact areas by taking into account wrench-length shrinkage caused by a vertical force. To evaluate the equations and determine constants included in the equations, we performed a series of calibration experiments using a manipulator-mounted tactile sensor and a combined load-testing machine. Subsequently. to evaluate the tactile sensor's practicality. it was mounted on the end of a robotic manipulator which rubbed flat specimens such as brass plates with step-heights of δ=0.05, 0.1, 0.2 mm and a brass plate with no step-height. We showed from the experimental data that the optical three-axis tactile sensor can detect not only the step-heights but also the distribution of the coefficient of friction, and that the sensor can detect fine plate inclination with accuracy to about ±0.4°.
Rabbit retinal ganglion cell responses to nicotine can be mediated
by β2-containing nicotinic acetylcholine receptors
Authors: STRANG CHRISTIANNE E. , AMTHOR FRANKLIN R. , KEYSER KENT T.
Published: April 2004

Acetylcholine (ACh) affects the response properties of many retinal
ganglion cells (GCs) through the activation of nicotinic acetylcholine
receptors (nAChRs). To date there have been few studies directly
correlating the expression of specific nAChR subtypes with the
physiological and morphological characteristics of specific retinal
GCs. This study was designed to correlate responses to nicotine
application with immunohistochemical evidence of nAChR expression in
physiologically and morphologically identified ganglion cells.
Extracellular recordings were used to physiologically identify rabbit
retinal GCs, based on responses to light stimulation. Cells were then
tested for responses to nicotine application and/or for expression
of nAChRs, as judged by immunoreactivity to mAb210, an nAChR antibody.
The morphologies of many physiologically identified cells were also
determined by dye injection. More than three-fourths of ganglion cells
tested responded to nicotine application under cobalt-induced synaptic
blockade. The nicotine sensitivity was consistent with nAChR
immunoreactivity and was also correlated with specific morphological
subgroups of GCs. Overall, approximately two-thirds of all
physiologically identified GCs that were processed for
immunohistochemistry displayed immunoreactivity. In total, 18 of 22
physiologically identified cells demonstrated both sensitivity to
nicotine application under synaptic blockade and mAb210
immunoreactivity (mAb210-IR). Thus, mAb210-IR is likely to represent
functional nAChRs that can modulate retinal information processing and
visual functioning via direct excitation of a number of GC
classes.
Visual detection deficits following inactivation of the superior
colliculus in the cat
Authors: FITZMAURICE MARNIE C. , CIARAMITARO VIVIAN M. , PALMER LARRY A. , ROSENQUIST ALAN C.
Published: April 2004

Lesion or inactivation of the superior colliculus (SC) of the cat
results in an animal that fails to orient toward peripheral visual
stimuli which normally evoke a brisk, reflexive orienting response. A
failure to orient toward a visual stimulus could be the result of a
sensory impairment (a failure to detect the visual stimulus) or a motor
impairment (an inability to generate the orienting response). Either
mechanism could explain the deficit observed during SC inactivation
since neurons in the SC can carry visual sensory signals as well as
motor commands involved in the generation of head and eye movements. We
investigated the effects of SC inactivation in the cat in two ways.
First, we tested cats in a visual detection task that required the
animals to press a central, stationary foot pedal to indicate detection
of a peripheral visual stimulus. Such a motor response does not involve
any components of the orienting response and is unlikely to depend on
SC motor commands. A deficit in this task would indicate that the SC
plays an important role in the detection of visual targets even in a
task that does not require visual orienting. Second, to further
investigate the visual orienting deficit observed during SC
inactivation and to make direct comparisons between detection and
orienting performance, we tested cats in a standard perimetry paradigm.
Performance in both tasks was tested following focal inactivation of
the SC with microinjections of muscimol at various depths and
rostral/caudal locations throughout the SC. Our results reveal a
dramatic deficit in both the visual detection task and the visual
orienting task following inactivation of the SC with muscimol.
On the process and aesthetics of sampling in electronic music production
Authors: RODGERS TARA
Published: April 2004

Most scholars writing on the use of samplers express anxiety over the dissolution of boundaries between human-generated and automated musical expression, and focus on the copyright infringement issues surrounding sampling practices without adequately exploring samplists' musical and political goals. Drawing on musical examples from various underground electronic music genres and on interviews with electronic musicians, this essay addresses such questions as: What is a sampler, and how does the sampling process resonate with or diverge from other traditions of instrument-playing? How do electronic musicians use the ‘automated’ mechanisms of digital instruments to achieve nuanced musical expression and cultural commentary? What are some political implications of presenting sampled and processed sounds in a reconfigured compositional environment? By exploring these issues, I hope to counter the over-simplified, uninformed critical claims that sampling is a process of ‘theft’ and ‘automation’, and instead offer insight into the myriad and complex musical and political dimensions of sampling in electronic music production.