bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison and Evaluation of Osiris and Sirscan 2000 Antimicrobial Susceptibility Systems in the Clinical Microbiology Laboratory
Authors: Nijs A. , Cartuyvels R. , Mewis A. , Peeters V. , Rummens J. L. , Magerman K.
Published: August 2003

The Osiris and Sirscan 2000 systems are two semiautomated systems that can be used to read and interpret the results on disk diffusion agar plates. They are both used for determination of susceptibility to antimicrobial agents. The present study compared both systems versus the NCCLS standard method of visual reading with a ruler. Both inpatient and outpatient samples with a total of 315 nonfastidious gram-negative strains were obtained. In total, 3,724 organism-antimicrobial agent combinations that fulfilled the NCCLS guidelines for disk diffusion susceptibility testing were evaluated prospectively. The results obtained with both systems in comparison with those obtained by the classical nonautomated means of interpretation were excellent, with correlation coefficients of 0.96 for both systems. The overall agreements for susceptibility interpretation were 96.56 and 96.24% with the Osiris and Sirscan systems, respectively. Very major errors were obtained for 8 (1.07%) and 10 (1.34%) organism-antimicrobial agent combinations with the Osiris and Sirscan systems, respectively. In addition, major errors were obtained for 2 (0.07%) and 6 (0.21%) combinations with the Osiris and Sirscan systems, respectively. Minor errors were obtained for 118 and 124 organism-antimicrobial agent combinations with the Osiris and Sirscan systems, respectively. Overall, both the Osiris system and the Sirscan system are comparable and reliable systems for determination of interpretative categories from the zone diameters of standard disk diffusion test plates.
Detection of Clarithromycin-Resistant
Helicobacter pylori
in Stool Samples
Authors: Fontana Carla , Favaro Marco , Pietroiusti Antonio , Pistoia Enrico Salvatore , Galante Alberto , Favalli Cartesio
Published: August 2003

The recognition of the role of
Helicobacter pylori
in gastric diseases has led to the widespread use of antibiotics in the eradication of this pathogen. The most advocated therapy, triple therapy, often includes clarithromycin. It is well known that clarithromycin resistance is one of the major causes of eradication failure. The development of a rapid noninvasive technique that could easily be performed on fecal samples and that could also provide information about the antibiotic resistance of this microorganism is therefore advisable. Previous findings have demonstrated that clarithromycin resistance is due to a single point mutation in the 23S rRNA. All the mutations described have been associated with specific restriction sites, namely
Bsa
I (A2143G),
Mbo
II (A2142C/G), and
Hha
I (T2717C). On this basis we have developed a new method, a seminested PCR, allowing screening for clarithromycin resistance of
H. pylori
directly on stool samples. This method furnished a 783-bp fragment of the 23S rRNA, which was subsequently digested by
Mbo
II,
Bsa
I, and
Hha
I, in order to identify single point mutations associated with clarithromycin resistance. Of a total of 283 stool samples examined, 125 were
H. pylori
positive and two of them were shown to contain clarithromycin-resistant strains due to the presence of a mutation at position 2717, whereas no PCR products contained mutations at position 2142 or 2143. In order to evaluate the reliability of the new system, we compared the results of restriction analysis of the PCR products with the MICs shown by the
H. pylori
isolates by culturing gastric biopsies from the same patients.
Optimization and Validation of Multilocus Sequence Typing for
Candida albicans
Authors: Tavanti Arianna , Gow Neil A. R. , Senesi Sonia , Maiden Martin C. J. , Odds Frank C.
Published: August 2003

Multilocus sequence typing (MLST) was applied to 75
Candida albicans
isolates, including 2 that were expected to be identical, 48 that came from diverse geographical and clinical sources, and 15 that were sequential isolates from two patients. DNA fragments (≈500 bp) of eight genes encoding housekeeping functions were sequenced, including four that have been described before for
C. albicans
MLST, and four new gene fragments,
AAT1a
,
AAT1b
,
MPI
, and
ZWF1
. In total, 87 polymorphic sites were found among 50 notionally different isolates, giving 46 unique sequence types, underlining the power of MLST to differentiate isolates for epidemiological studies. Additional typing information was obtained by detecting variations in size at the transcribed spacer region of the 25S rRNA gene and tests for homozygosity at the mating type-like (MTL) locus. The stability of MLST was confirmed in two sets of consecutive isolates from two patients. In each set the isolates were identical or varied by a single nucleotide. Reference strain SC5314 and a derived mutant, CAF2, gave identical MLST types. Heterozygous polymorphisms were found in at least one isolate for all but 16 (18.4%) of the variable nucleotides, and 35 (41%) of the 87 individual sequence changes generated nonsynonymous amino acids. Cloning and restriction digestion of a gene fragment containing heterozygous polymorphisms indicated that the heterozygosity was genuine and not the result of sequencing errors. Our data validate and extend previous MLST results for
C. albicans
, and we propose an optimized system based on sequencing eight gene fragments for routine MLST with this species.
Quantitative Real-Time PCR Assay for Detection of
Ehrlichia chaffeensis
Authors: Loftis Amanda D. , Massung Robert F. , Levin Michael L.
Published: August 2003

A real-time PCR assay was developed for the detection of
Ehrlichia chaffeensis
. The assay is species specific and provides quantitative results in the range 10 to 10
10
gene copies. The assay is not inhibited by the presence of tick, human, or mouse DNA and is compatible with high sample throughput. The assay was compared with previously described assays for
E. chaffeensis
.
Identification ofExophiala mesophilaIsolated from Treated Dental Unit Waterlines
Authors: Porteous N. B. , Grooters A. M. , Redding S. W. , Thompson E. H. , Rinaldi M. G. , De Hoog G. S. , Sutton D. A.
Published: August 2003

Members of the genusExophialaare often difficult to identify to the species level because of their variable morphological appearances. This paper describes the methods used to identifyExophiala mesophilaand provides salient differential features for distinguishing other mesophilic members of the genus.
The genetic basis of C-glycosyl flavone B-ring modification in maize (Zea maysL.) silks
Authors: Cortés-Cruz Moisés , Snook Maurice , McMullen Michael D
Published: August 2003

Resistance to corn earworm (CEW) (Helicoverpa zea Boddie) has been attributed to high concentrations of C-glycosyl flavones and chlorogenic acid in maize (Zea mays L.) silks. The most common C-glycosyl flavones isolated from maize silks are maysin, apimaysin, and methoxymaysin, which are distinguished by their B-ring substitutions. For a better understanding of the genetic mechanisms underlying the synthesis of these compounds, we conducted a quantitative trait locus (QTL) study with two populations: (Tx501 × NC7A)F2and (Tx501 × Mp708)F2. For chlorogenic acid, maysin, and methoxymaysin concentration, the major QTL for both populations was located on chromosome 4 near umc1963. For apimaysin, the major QTL in both populations was located at the position of the pr1 locus on chromosome 5. The QTL alleles on chromosome 4 that increased the synthesis of methoxymaysin significantly decreased the synthesis of maysin and chlorogenic acid. This decrease in maysin concentration was four-fold greater than the increase in methoxymaysin. Our results indicate that the QTL on chromosome 4, responsible for the increase in methoxymaysin synthesis, alters the dynamics of both the phenylpropanoid and flavonoid pathways.Key words: pr1, flavonoid 3'-hydroxylase, maysin, apimaysin, methoxymaysin.
The sugary-type isoamylase gene from rice andAegilops tauschii: characterization and comparison with maize andArabidopsis
Authors: Rahman S , Nakamura Y , Li Z , Clarke B , Fujita N , Mukai Y , Yamamoto M , Regina A , Tan Z , Kawasaki S , Morell M
Published: August 2003

Genes for an isoamylase-like debranching enzyme have been isolated from rice and Aegilops tauschii, the donor of the D genome to wheat. The structures of the genes are very similar to each other and to the maize SU1 isoamylase gene and consist of 18 exons spread over approximately 7.5 kb. Southern analysis and fluorescent in situ hybridization showed the Ae. tauschii gene to be located in the proximal region of the short arm of chromosome 7D, thus showing synteny with the localization of the rice isoamylase gene on rice chromosome 8. Analysis of the expression pattern of wheat sugary isoamylase genes indicates that they are strongly expressed in the developing endosperm 6 days after flowering. Three distinct Sugary-type cDNA sequences were isolated from the wheat endosperm that are likely to correspond to the products of the three genomes. The deduced amino acid sequence of rice and wheat Sugary-type isoamylase is compared with other sequences available in the database and the results demonstrate that there are three types of isoamylase sequences in plants: those containing 18 exons (the Sugary-type isoamylase gene), those containing 21 exons, and those containing only 1 exon. It is possible that different combinations of isoamylase genes are expressed in different tissues.Key words: isoamylase, rice, wheat, sugary, FISH.
The genetic diversity of theVigna angulariscomplex in Asia
Authors: Zong Xu Xiao , Kaga Akito , Tomooka Norihiko , Wang Xin Wang , Han Ouk Kyu , Vaughan Duncan
Published: August 2003

A selected set of accessions of components of the azuki bean (Vigna angularis) complex comprising 123 cultivated accessions and 23 wild or weedy accessions from Bhutan, China (including Taiwan), India, Japan, Korea, and Nepal was analyzed using amplified fragment length polymorphism (AFLP) methodology. Using 12 AFLP primer pairs, 580 unambiguous bands were generated, 313 (53.9%) of which were polymorphic among azuki bean accessions. All 580 bands were used to assess phenotypic (band) and genetic (nucleotide) diversity among the 146 azuki bean accessions. The results indicate five major groups of azuki bean germplasm primarily associated with geographic origin of accessions and their status: wild, weedy, or cultivated. These five groups are (i) Himalayan wild, (ii) NepalBhutan cultivated, (iii) Chinese wild, (iv) Taiwan wild  Bhutan cultivated, and (v) northeast Asian accessions. Within the northeast Asian accessions, three subgroups are present. These consist of (v1) Japanese complex  Korean cultivated, (v2) Japanese cultivated, and (v3) Chinese cultivated accessions. The results suggest domestication of azuki bean occurred at least twice, once in the Himalayan region of southern Asia and once in northeast Asia. The remarkable diversity of azuki bean germplasm in the Himalayan region compared with other regions suggests this is a rich source of germplasm for plant breeding. The results suggest there are important gaps in the germplasm collections of azuki bean and its close relatives from various parts of Asia and that specific collecting missions for Vigna germplasm related to azuki bean in the highlands of subtropical Asia are needed.Key words: AFLP markers, Asia, azuki bean, conservation, legume.
The Kepler Problem and Noncommutativity
Authors: Romero Juan M. , Vergara J. David
Published: August 2003

We investigate the Kepler problem using a symplectic structure consistent with the commutation rules of the noncommutative quantum mechanics. We show that a noncommutative parameter of the order of 10-58 m 2 gives observable corrections to the movement of the solar system. In this way, modifications in the physics of smaller scales imply modifications at large scales, something similar to the uv/ir mixing.
Absent Collateral Function of the Circle of Willis as Risk Factor for Ischemic Stroke
Authors: Hoksbergen A.W.J. , Legemate D.A. , Csiba L. , Csáti G. , Síró P. , Fülesdi B.
Published: August 2003

Background: Autopsy studies show a higher prevalence of circle of Willis anomalies in brains with signs of ischemic infarction. Our goal was to examine the collateral function of the circle of Willis in ischemic stroke patients and to assess in a case-control study if a collateral deficient circle of Willis is a risk factor for ischemic stroke in patients with severe internal carotid artery (ICA) occlusive disease. Methods: Our case-control study included 109 patients with an acute ischemic stroke in the anterior circulation and 113 patients with peripheral arterial disease and no known history of cerebral ischemia. The collateral function of the anterior and posterior communicating arteries of the circle of Willis was assessed by means of transcranial color-coded duplex ultrasonography (TCCD) and carotid compression tests. Results: TCCD was successfully performed in 75 case patients (mean age 64 years, range 41–91 years) and in 100 control patients (mean age 61 years, range 35–89 years). In 26 cases and 19 controls, a ≧70% stenosis or occlusion of the ICA was found. A nonfunctional anterior collateral pathway in the circle of Willis was found in 33% of the cases and in 6% of the controls (p < 0.001). The posterior collateral pathway was nonfunctional in 57% of the cases and in 43% of the controls (p = 0.02). In patients with severe ICA occlusive disease, the odds ratios of a nonfunctional anterior and a nonfunctional posterior collateral pathway were 7.33 (95% confidence interval, CI, = 1.19–76.52) and 3.00 (95% CI = 0.77–12.04), respectively. Conclusions: Patients who suffer ischemic stroke in the anterior circulation have a higher incidence of collateral deficient circles of Willis than those with atherosclerotic vascular disease without ischemic cerebrovascular disease. The presence of a nonfunctional anterior collateral pathway in the circle of Willis in patients with severe ICA occlusive disease is strongly associated with ischemic stroke.
Chromatin reprogramming of male somatic cell-derived Xist and Tsix in ES hybrid cells
Authors: Kimura H. , Tada M. , Hatano S. , Yamazaki M. , Nakatsuji N. , Tada T.
Published: August 2003

In mammalian somatic cells, the X chromosome is active in XY males, whereas one X chromosome is inactivated in XX females. On the active male X chromosome, the Xist and Tsix genes are transcribed in undifferentiated cells of pre-implantation embryos (undifferentiated state) and then down-regulated upon cell differentiation (differentiated state). To explore the epigenetic mechanism involved in the on-off switching of Xist and Tsix transcription in the active X chromosome, male somatic cells were hybridized with male embryonic stem (ES) cells. Fluorescence in situ hybridization analysis revealed that the Xist gene derived from somatic cells was derepressed, as shown by the advent of two pinpoint signals. This was confirmed by strand-specific RT-PCR of Xist and Tsix genes. To analyze changes in chromatin structure in the promoter regions of Xist and Tsix derived from somatic cells, histone tail modifications were studied by chromatin immunoprecipitation analysis. Histones H3 and H4, which were hypoacetylated in the somatic cells, were hyperacetylated in the hybrid cells, and histone H3 lysine 4, which was hypomethylated in the somatic cells, was hypermethylated in the hybrid cells, indicating that the reactivation of Xist and Tsix was linked with chromatin modifications. In the telomeric region of DXPas34, acetylation of histones H3 and H4 was dependent on reactivation of Xist and Tsix, whereas histone H3 lysine 4 was constitutively methylated independent of the transcriptional activity of those genes. We propose that the chromatin reprogramming is linked with the resetting of the memory found in the process of choosing an active X chromosome.
The evolution of sex chromosomes
Authors: Ayling L.-J. , Griffin D.K.
Published: August 2003

Mammalian sex chromosomes appear, behave and function differently than the autosomes, passing on their genes in a unique sex-linked manner. The publishing of Ohno’s hypothesis provided a framework for discussion of sex chromosome evolution, allowing it to be developed and challenged numerous times. In this report we discuss the pressures that drove the evolution of sex and the mechanisms by which it occurred. We concentrate on how the sex chromosomes evolved in mammals, discussing the various hypotheses proposed and the evidence supporting them.
Fertility, sex determination, and the X chromosome
Authors: Vaiman D.
Published: August 2003

Because of its function, the X chromosome has a special status in mammalian genomes, with the specific occurrence of genes that influence both female and male fertility. Long ago, the XO karyotype (Turner syndrome) was associated with infertility, proving the correlation between normal X chromosome dosage and normal female fertility. Nevertheless, the search for specific X-borne fertility genes was not completely successful and suggested, instead, that female X-linked fertility, for example, depends upon groups of X-linked genes. Conversely, X-linked hyperfertility has been observed in sheep, where a mutation in BMP15 leads to a hyperfertile phenotype, but only in the heterozygous state. Many male fertility genes map to the X chromosome, consistent with a genetic model developed in the early 1990s. Ironically, NR0B1 (formerly DAX1), once presented as the paradigm of genes responsible for ovarian development and function, is probably one of these male fertility factors and is active in the maintenance of spermatogenesis. Indeed, duplications of this gene on the human X chromosome lead to XY sex reversal, as NR0B1 is able to counterbalance the effect in humans. Nevertheless, invalidation experiments in mice demonstrate the effect of this factor on male germ-cell production.
Biallelic expression of Z-linked genes in male chickens
Authors: Kuroiwa A. , Yokomine T. , Sasaki H. , Tsudzuki M. , Tanaka K. , Namikawa T. , Matsuda Y.
Published: August 2003

In birds, females are heterogametic (ZW), while males are homogametic (ZZ). It has been proposed that there is no dosage compensation for the expression of Z-linked genes in birds. In order to examine if the genes are inactivated on one of the two Z chromosomes, we analyzed the allelic expression of the B4GALT1 and CHD-Z genes on Z chromosomes in male chickens. One base substitution was detected among 15 chicken breeds and lines examined for each gene, and cross mating was made between the breeds or lines with polymorphism. cDNAs were synthesized from cultured cell colonies each derived from a single cell of an F1 male embryo. The allelic expression of the B4GALT1 gene was examined by restriction fragment length polymorphism analysis of the PCR products digested with RsaI, and that of the CHD-Z gene by the single nucleotide primer extension (SNuPE) method. Both of the genes displayed biallelic expression, suggesting that these Z-linked genes were not subject to inactivation in male chickens. Comparison between expression levels in males and females by real-time quantitative PCR suggested that expression was compensated for the CHD-Z gene but not for the B4GALT1 gene.
The X chromosome deletion in Hyp mice extends into the intergenic region but does not include the Sat gene downstream from Phex
Authors: Sabbagh Y. , Gauthier C. , Tenenhouse H.S.
Published: August 2003

The murine Hyp mutation is a model for X-linked hypophosphatemia (XLH), the most prevalent form of inherited rickets in humans. Although mutations in the murine Phex gene and the human PHEX gene have been identified in both murine and human disorders, the extent of the Hyp deletion on the mouse X chromosome has not been delineated. In the present study we demonstrate that the Hyp deletion starts in the middle of Phex intron 15 and includes ∼48 kb of the 3′ region of the Phex gene and ∼10 kb of intergenic sequence on the mouse X chromosome. In addition, we show that the Hyp deletion does not involve the downstream spermidine/spermine N1-acetyl transferase (Sat; formerly Ssat) gene and thus is not a contiguous gene deletion syndrome. Our data indicate that the Hyp mouse is a true homolog of XLH in humans and underscore the validity of this murine model in studies of XLH pathophysiology and for testing novel treatment modalities.
Beta-Galactosidase-Tagged Adventitial Myofibroblasts Tracked to the Neointima in Healing Rat Vein Grafts
Authors: Tomas Jeffrey J. , Stark V. Emily , Kim Jimmy L. , Wolff Randal A. , Hullett Debra A. , Warner Thomas F. , Hoch John R.
Published: August 2003

Objective: Myofibroblasts are present transiently in normal healing wounds. However, they have been found to persist in the stroma of neoplasms, fibrotic conditions and other pathological settings. In rat vein grafts, we have observed the prolonged presence of myofibroblasts. Our aim was to determine the origin of myofibroblasts in vein grafts. Methods: Epigastric vein to femoral artery grafts were microsurgically placed in male Lewis rats and harvested. Neointimal development, cellular death and proliferation, and cell phenotypes were analyzed using immunohistochemistry and light and electron microscopy. To follow cellular movement in the vessel wall, vein grafts were transfected with replication-defective adenovirus containing the gene encoding β-galactosidase (n = 50), and harvested at 1, 2, 3, 4, 5, 6, 7, 14 and 28 days. Grafts were analyzed after X-gal staining. Results: Myofibroblasts were detected in the outer adventitia at 4 days, in the media at 1 week and in the developing neointima at 2 weeks. Cells tagged using adenoviral β-galactosidase demonstrated adventitia to neointima cell migration. Conclusions: Although there may be other sources of myofibroblasts in this model, the adventitia has been shown to be an origin of myofibroblasts which subsequently migrate through the vessel wall to the neointima during graft remodeling and contribute to neointimal formation.
Regulation of Matrix Metalloproteinase (Matrixin) Genes in Blood Vessels: A Multi-Step Recruitment Model for Pathological Remodelling
Authors: Chase Alex J. , Newby Andrew C.
Published: August 2003

Matrix metalloproteinases (MMPs; matrixins) are a family of structurally related enzymes that collectively promote turnover of all components of the extracellular matrix. Matrix turnover is required for vascular repair, but, if excessive, leads to pathologies that include aneurysm formation and atherosclerotic plaque instability. We review the positive and negative regulation of metalloproteinase gene induction. We propose that multiple steps of gene induction recruit a wider spectrum of MMPs, which may ultimately lead to a transition from matrix turnover to matrix destruction. Studying the detailed mechanisms involved may suggest possibilities for intervening selectively against pathological MMP induction.
CD34+ Blood Cells Accelerate Vascularization and Healing of Diabetic Mouse Skin Wounds
Authors: Sivan-Loukianova E. , Awad O.A. , Stepanovic V. , Bickenbach J. , Schatteman G.C.
Published: August 2003

Diabetes is characterized by poor circulation and impaired angiogenesis, which appear to contribute to the frequent skin lesions and poor wound healing common in diabetic patients. Therapies to improve circulation commonly improve wound healing in diabetic patients. Administration of circulating CD34+ cells, cells that can function as endothelial cell progenitors, accelerates blood flow restoration to ischemic limbs of diabetic mice. We have investigated the potential of these cells to accelerate revascularization and healing in full-thickness skin wounds of hypoinsulinemic (streptozotocin-treated) diabetic mice. Wounds were injected with human CD34+ or CD34– peripheral blood mononuclear cells or no cells, and analyzed for vascularity and healing at various times thereafter. Treatment with CD34+ enriched cells decreased wound size by 4 days after treatment, accelerated epidermal healing, and rapidly and dramatically accelerated revascularization of the wounds compared to controls. Initially increased vascularization was mediated principally by an increase in vessel diameter, but later, both an increase in vascular size and number were observed. These findings indicate that blood-derived progenitors may have therapeutic potential in the treatment of skin lesions in the setting of diabetes, and give insights into how bone marrow cells exert their effects on neovascularization.
Signal Transduction in Matrix Contraction and the Migration of Vascular Smooth Muscle Cells in Three-Dimensional Matrix
Authors: Li Song , Moon James Jaehyun , Miao Hui , Jin Gang , Chen Benjamin P.C. , Yuan Suli , Hu Yingli , Usami Shunichi , Chien Shu
Published: August 2003

The interaction of vascular smooth muscle cells (SMCs) and extracellular matrix plays important roles in vascular remodeling. We investigated the signaling pathways involved in SMC-induced matrix contraction and SMC migration in three-dimensional (3D) collagen matrix. Matrix contraction is inhibited by the disruption of actin filaments but not microtubules. Therefore, we investigated the roles of signaling pathways related to actin filaments in matrix contraction. SMC-induced matrix contraction was markedly blocked (–80%) by inhibiting the Rho-p160ROCK pathway and myosin light chain kinase, and was decreased to a lesser extent (30–40%) by a negative mutant of Rac and inhibitors of phosphatidylinositol 3-kinase (PI 3-kinase) or p38 mitogen-activated protein kinase (MAPK), but it was not affected by the inhibition of Ras and Cdc42-Wiskott-Aldrich syndrome protein (WASP) pathways. Inhibition of extracellular-signal-regulated kinase (ERK) decreased SMC-induced matrix contraction by only 15%. The migration speed and persistence of SMCs in the 3D matrix were decreased by the inhibition of p160ROCK, PI 3-kinase, p38 MAPK or WASP to different extents, and p160ROCK inhibitor had the strongest inhibitory effect. Our results suggest that the SMC-induced matrix contraction and the migration of SMCs in 3D matrix share some signaling pathways leading to force generation at cell-matrix adhesions and that various signaling pathways have different relative importance in the regulations of these processes in SMCs.
Intussusception in Adults: A 21-Year Experience in the University-Affiliated Emergency Center and Indication for Nonoperative Reduction
Authors: Omori Hiroaki , Asahi Hiroshi , Inoue Yoshihiro , Irinoda Takashi , Takahashi Masahiro , Saito Kazuyoshi
Published: August 2003

Background: While intussusception is relatively common in children, it is rare in adults. Methods: We retrospectively reviewed the records of all patients older than 18 years with the diagnosis of intussusception between 1981 and 2001. Results: Eleven patients with surgically or endoscopically proven intussusception were encountered at the University-affiliated emergency center. The patients ranged in age from 19 to 88 years with a mean age of 45 years. Males predominated by a ratio of 7:4. Most patients (82%) presented with symptoms of bowel obstruction. The mean duration of symptoms was 4.5 days with a range of 4 h to 25 days. Correct pre-treatment diagnosis was made in 82% of the patients using abdominal ultrasonography and computed tomography (CT). The causes of intussusception were organic lesions in 64% of the patients, postoperative in 18% and idiopathic in 18%, respectively. 73% of patients had emergency operations, and an attempt at nonoperative reduction was performed and completed successfully in 3 patients with ileo-colic or colonic type of intussusception. There have been no cases of morbidity or mortality in our series and no recurrence has occurred up to the present time. Conclusions: Abdominal ultrasonography and CT were effective tools for the diagnosis of intussusception. Patients with ileo-colic and colonic intussusception without malignant lesions could be good candidates for nonoperative reduction prior to definitive surgery.
Preoperative Natural Killer Cell Activity as a Prognostic Factor for Distant Metastasis following Surgery for Colon Cancer
Authors: Kondo Eisuke , Koda Keiji , Takiguchi Nobuhiro , Oda Kenji , Seike Kazuhiro , Ishizuka Mitsuru , Miyazaki Masaru
Published: August 2003

Background/Aims: To determine whether preoperative natural killer (NK) cell activity has any prognostic significance in colon cancer patients. Methods: The study population consisted of 140 patients with colon cancer. NK cell activity was determined within 2 weeks before surgery in 128 patients and at the time of diagnosis in the remaining 12 patients who either did not undergo surgery or who underwent palliative surgery only. Disease progression and postoperative prognosis were examined in relation to NK cell activity. Results: Decreases in NK cell activity did not necessarily correspond to tumor stage. In curatively operated stage I–III diseases, preoperative NK cell activity of 20% or less correlated with poor survival. Lower activity was also associated with metachronous distant metastases but not with local recurrences. In particular, more than half the stage III patients with attenuated NK cell activity developed metastases. Multivariate analysis indicated that attenuated NK cell activity was a significant parameter for predicting distant metastasis following curative surgery for colon cancer. Conclusion: Preoperative NK cell activity has a significant prognostic value in curatively operated colon cancer, particularly for the development of metachronous distant metastasis in stage III patients.
TheArabidopsis ACR4gene plays a role in cell layer organisation during ovule integument and sepal margin development
Authors: Gifford Miriam L. , Dean Samuel , Ingram Gwyneth C.
Published: August 2003

The mechanisms regulating cell layer organisation in developing plant organs are fundamental to plant growth, but remain largely uninvestigated. We have studied the receptor kinase-encoding ARABIDOPSIS CRINKLY4 gene and shown that its expression is restricted to the L1 cell layer of most meristems and organ primordia, including those of the ovule integuments. Insertion mutations show that ARABIDOPSIS CRINKLY4 is required for regulation of cellular organisation during the development of sepal margins and ovule integument outgrowth. We show that ARABIDOPSIS CRINKLY4encodes a functional kinase that, in ovules and possibly other tissues, is abundant in anticlinal and the inner periclinal plasma membrane of `outside'cells. We propose that ARABIDOPSIS CRINKLY4 may be involved in maintaining L1 cell layer integrity by receiving and transmitting signals from neighbouring L1 cells and/or from underlying cell layers.
A Twist-like bHLH gene is a downstream factor of an endogenous FGF and determines mesenchymal fate in the ascidian embryos
Authors: Imai Kaoru S. , Satoh Nori , Satou Yutaka
Published: August 2003

Ascidian larvae develop mesenchyme cells in their trunk. A fibroblast growth factor (FGF9/16/20) is essential and sufficient for induction of the mesenchyme in Ciona savignyi. We have identified two basic helix-loop-helix (bHLH) genes named Twist-like1 and Twist-like2 as downstream factors of this FGF. These two genes are phylogenetically closely related to each other, and were expressed specifically in the mesenchymal cells after the 110-cell stage. Gene-knockdown experiments using a specific morpholino oligonucleotide demonstrated that Twist-like1 plays an essential role in determination of the mesenchyme and that Twist-like2 is a downstream factor of Twist-like1. In addition, both overexpression and misexpression of Twist-like1 converts non-mesenchymal cells to mesenchymal cells.

We also demonstrate that the upstream regulatory mechanisms of Twist-like1 are different between B-line mesenchymal cells and the A-line mesenchymal cells called `trunk lateral cells'. FGF9/16/20 is required for the expression of Twist-like1 in B-line mesenchymal precursor cells, whereas FGF, FoxD and another novel bHLH factor called NoTrlc are required for Twist-like1 to be expressed in the A-line mesenchymal precursor cells. Therefore, two different but partially overlapping mechanisms are required for the expression of Twist-like1 in the mesenchymal precursors, which triggers the differentiation of the mesenchyme in Ciona embryos.
In‐situ near infrared spectroscopy to monitor key analytes in mammalian cell cultivation
Authors: Arnold S. Alison , Crowley John , Woods Nigel , Harvey Linda M. , McNeil Brian
Published: August 2003

The use of in‐situ near infrared spectroscopy (NIRS) as a tool for monitoring four key analytes in a CHO‐K1 animal cell culture was investigated. Previous work using on‐line NIRS to monitor bioprocesses has involved its application ex‐situ where the analyzer is physically outside the fermentor, or to microbial bioprocesses. This novel application of NIRS to monitor analytes within an animal cell culture using a steam sterilizable in‐situ fiber optic probe is very important for furthering the use of NIRS within the bioprocessing industry. The method of calibration used to develop the models involved the use of large data sets so that all likely variation in stoichiometry was incorporated within the models. Successful models for glucose, lactate, glutamine, and ammonia were built with Standard Error of Predictions (SEP's) of 0.072 (g/L), 0.0144 (g/L), 0.308 (mM), and 0.036 (mM), respectively of the total concentration range. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 84: 13–19, 2003.
Long‐term continuous evolution of acetate resistant Acetobacter aceti
Authors: Steiner Peter , Sauer Uwe
Published: August 2003

Elevated concentrations of cytotoxic acetate are found in many environmental niches, and few species are relatively resistant to acetate. In particular the high‐level acetate resistance of so‐called acetic acid bacteria that occurs in industrial settings must be constantly selected for. To investigate the nature of such high‐level resistance, we grew the moderately acetate‐resistant Acetobacter aceti wild‐type and acetate‐sensitive Escherichia coli in long‐term continuous cultures with increasing acetate concentrations at near neutral pH. While E. coli did not acquire any significant resistance after 125 generations of selection, A. aceti evolved the capability to grow at acetate concentrations exceeding 50 g/L within 240 generations. This phenotype was found to be stable for several generations in the absence of selective pressure, hence must be genetically determined. Intracellular acetate concentrations were significantly lower in evolved A. aceti, when compared to wild‐type A. aceti and E. coli, indicating that cytoplasmatic anion accumulation is an important component of acetate toxicity. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 84: 40–44, 2003.
Fiscal instruments in sustainable housing policies in the EU and the accession countries
Authors: Sunikka Minna
Published: August 2003

Although progressive government guidelines and knowledge about sustainable housing exist, progress in implementing them in practice has been slow. The perceived costs and the lack of market demand have been identified as the main barriers. A choice of fiscal instruments is essential in sustainable housing policies. This article presents an analysis of economic measures currently used to support sustainable housing in the EU and the accession countries, indicating the areas where policy instruments are either focused or lacking. Based on the country progress reports of the Third European Ministers Conference on Sustainable Housing in Belgium in 2002, the results indicate that environmental taxes and subsidies are used in the EU and the accession countries, but that they have had a low impact on the housing sector. An examination of the developments since 1996 shows that apart from energy initiatives resulting from the Kyoto Protocol, the lack of a strong driving force has kept progress slow. Conclusions are based on the analysis findings – the low impact of taxation on housing, the lack of environmental criteria in the reduced VAT rate and the narrow focus of subsidies. This article argues that enlargement of the EU presents opportunities for sustainable housing in Europe, if the fiscal instruments are enforced by legal means. Copyright © 2003 John Wiley & Sons, Ltd and ERP Environment.
Runoff production processes in small alpine catchments within the unconsolidated Pleistocene sediments of the Lainbach area (Upper Bavaria)
Authors: Wetzel Karl‐Friedrich
Published: August 2003

In the Lainbach catchment, unconsolidated Pleistocene moraine sediments are widely distributed. Because of the great natural risk of floods, together with extreme loads of sediments, investigations of runoff production processes have been conducted in this area. At hillslope scale three test sites with different states of soil development and vegetation cover were instrumented with V‐shaped weirs, precipitation gauges and measurement devices for electrical conductivity (EC) of discharge water. The EC has been used as a geochemical tracer for hydrograph separation, since the statistical relationship between content of dissolved Ca2+, Mg2+ cations and EC is highly significant for different stages of runoff. This method allows hydrograph separation at high temporal resolution for both the rising and falling limb of the hydrograph. The following results of the investigations can be resumed. If relief conditions are similar, the effectiveness of runoff production decreases with an increasing density of vegetation cover. The runoff delivery ratio decreases as well as the peaks of runoff. In contrast, concentration times of hillslope catchments are equal, even if vegetation cover is of great density and soils are well developed. As a reason for the short reaction times, different runoff production processes have been detected. On bare ground, infiltration excess overland flow intensified by surface sealing processes is the main source for quick runoff. On hillslopes well covered by vegetation, translatory flow processes indicated by soil water with high solute contents force a rapid runoff reaction only a few minutes after rainfall has begun. It is to be assumed that translatory flow is a runoff production process typical for hillslopes covered by vegetation in a steep alpine relief. By means of the areal distribution of the topographic index, concentration of runoff production on a small part of the catchment has been demonstrated for hillslopes densely covered by vegetation. The investigations have shown that there is a lack of studies on runoff production processes in steep alpine relief, as well as a deficit of methods to quantify hydraulic properties of coarse‐grained soils with a wide grain size distribution. Copyright © 2003 John Wiley & Sons, Ltd.
A dynamically gain‐flattened erbium‐doped fiber amplifier
Authors: Lu Z. G. , Lin P. , Grover C. P.
Published: August 2003

This paper reports on dynamically gain‐flattened C‐ and L‐band erbium‐doped fiber amplifiers (DGF‐EDFAs), whose dynamic gain ranges are above 20 dB and 24 dB, respectively. This paper gives the detailed test and comparative results for DGF‐EDFAs based on the use of a voltage‐controlled fiber‐based gain tilt controller and a variable optical attenuator. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 8–11, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11110
Satellite communication with moving vehicles on earth: Two prototype circular array antennas
Authors: Ares F. , Franceschetti G. , Mosig J. , Vaccaro S. , Vassal'lo J. , Moreno E.
Published: August 2003

The performance of two minimal prototype antennas validates a novel design concept for a vehicle‐borne antenna for communications via satellite: the toroidal beam antenna implemented by a ring or rings of microstrip patches. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 14–16, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11112
A wideband coplanar‐waveguide‐fed multi‐slot antenna for radar applications
Authors: Allen Cuthbert M. , Eldek Abdelnasser A. , Elsherbeni Atef Z. , Smith Charles E.
Published: August 2003

A small multi‐slot antenna is designed for RF and microwave sensors and radar applications. The design was realized using a series of parallel slots with tapered lengths, fed by a coplanar waveguide (CPW) to support wideband operation. The designed multi‐slot antenna provides a 50% bandwidth centered at 10 GHz with 50Ω input impedance. The operating bandwidth remains almost constant regardless of the length of the feeding mechanism. This feature is demonstrated by several numerical simulations. Return loss, input impedance, radiation pattern, gain, and efficiency of the proposed design are computed and analyzed to support X‐band operation. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 24–27, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11116
Demonstration of an all‐optical logic OR gate using gain saturation in an SOA
Authors: Hamie Ali , Sharaiha Ammar , Guegan Mikael
Published: August 2003

In this paper, the all‐optical realization of a logic OR gate using gain saturation in a standard semiconductor optical amplifier (SOA) is successfully experimentally demonstrated. This reported feasibility study shows the all‐optical OR function can be easily achieved with an extinction ratio of about 7 dB. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 39–42, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11120
A new type of slotted waveguide and moving couplers for shielded microwave transfer
Authors: Sommavilla Diego , Liess Martin , Leyten Lukas
Published: August 2003

We present a novel small coaxial broadband slotted waveguide that can be used where size is a critical factor. We further present adapted directional and bidirectional wave couplers that can be introduced into the waveguide to launch and detect signals. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 42–44, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11121
A fully integrated concurrent dual‐band CMOS low‐noise amplifier
Authors: Zhang Y. P. , Chew K. W. , Wong P. F. , Do M. A.
Published: August 2003

This paper presents a fully integrated concurrent dual‐band CMOS low‐noise amplifier (LNA). The LNA is implemented in a standard 0.18‐μm 6M1P CMOS process and is designed from the system viewpoint to provide higher gain at the higher band, for the first time, to compensate the higher‐band signal's extra loss over the air transmission. The LNA drains 5.3 mA of current from a 1.8‐V supply voltage and achieves voltage gains of 16 and 22.5 dB, input return losses of 28 and 27 dB, and noise figures of 3.0 and 3.1 dB at 2.4 and 5.2 GHz, respectively. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 52–53, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11124
Ga0.51In0.49P/InxGa1−xAs/GaAs doped‐channel FETs (DCFETs) and their applications on monolithic microwave integrated circuits (MMICs)
Authors: Lin Yo‐Sheng , Chen Chih‐Chen , Lu Shey‐Shi
Published: August 2003

In this paper, lattice‐matched Ga0.51In0.49P/GaAs and strained Ga0.51In0.49P/In0.2Ga0.8As doped‐channel FETs (DCFETs) were investigated in terms of DC and microwave performances, including frequency response, noise figure, power‐added efficiency (PAE), and output power. In addition, small‐signal and large‐signal models were created for designing monolithic microwave integrated circuits (MMICs). The heterostructures were both grown by gas‐source molecular beam epitaxy (GSMBE) on semi‐insulating (100) GaAs substrates. In situ reflection high‐energy electron diffraction (RHEED) was used to calibrate the growth rate of InP and GaP. Because of the high etching selectivity between Ga0.51In0.49P and In0.2Ga0.8As/GaAs, the uniformity of the measured electrical properties of our fabricated devices is quite satisfying, which indicates that these Ga0.51In0.49P/InxGa1−xAs structures are very suitable for mass production. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 56–62, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11126
1H, 13C and 15N NMR spectroscopic, x‐ray structural and ab initio/HF studies on nitramino and N‐alkylamino‐4‐nitro derivatives of pyridine N‐oxides and pyridines
Authors: Laihia Katri , Kolehmainen Erkki , Virtanen Elina , Nissinen Maija , Puszko Aniela , Talik Zofia
Published: August 2003

The 1H, 13C and 15N NMR spectra in DMSO‐d6 were measured for eight nitraminopyridine N‐oxides, ten 4‐nitropyridine N‐oxides, four 2‐nitraminopyridines and five 4‐nitropyridines. Their chemical shift assignments are based on PFG 1H,X (X = 13C and 15N) HMQC and HMBC experiments. The relative energies for the tautomers of two nitraminopyridine N‐oxides were determined by ab initio HF/6–311G** calculations. A single‐crystal x‐ray structural analysis was made for 4‐methyl‐2‐nitraminopyridine: C6H7O2N3, M = 153.15, triclinic, space group P‐1 (No. 2), a = 7.0275(4), b = 6.8034(3), c = 8.6086(5) Å, α = 103.620(2), β = 90.309(2), γ = 122.215(3)°, V = 334.11(3) Å3, Z = 2. Copyright © 2003 John Wiley & Sons, Ltd.
Analysis of the 1H and 13C NMR spectra of bicyclo[6.2.1]undecane ring systems
Authors: Gomes Constantino Mauricio , Thiago de Oliveira Kleber , Beatriz Adilson , José da Silva Gil Valdo
Published: August 2003

A detailed NMR analysis with full assignment of the 1H and 13C spectral data for two polycyclic compounds is described. These compounds are derivatives of the product obtained from the pericyclic reaction between cyclopentadiene and tropone. Peculiar intriguing conformational features of these molecules are discussed. Copyright © 2003 John Wiley & Sons, Ltd.
Assessing the potential of fast amplitude modulation pulses for improving triple‐quantum magic angle spinning NMR spectra of half‐integer quadrupolar nuclei
Authors: Morais C. M. , Lopes M. , Fernandez C. , Rocha J.
Published: August 2003

A comprehensive experimental and numerical study of the potential of fast amplitude (FAM) irradiation for improving the triple‐quantum (3Q) magic angle spinning (MAS) NMR spectra of half‐integer $I > {1 \over 2}$ nuclei (23Na, 27Al, 45Sc, 93Nb) was carried out. Materials of academic and industrial importance, such as infrared‐emitter Na3YSi3O9, microporous aluminophosphate VPI‐5, mineral andalusite, calcined kaolinite, Sc2O3 and relaxor ferroelectric PMN, were investigated. It was found that FAM pulses are indeed of practical relevance and particularly useful for the observation of the NMR resonances given by nuclei in distorted local environments (large quadrupole coupling constants). In addition, a novel strategy for the optimization of the FAM‐II MQ MAS NMR experiment, which improves the multiple‐ to single‐quantum coherence transfer efficiency, is also reported. Copyright © 2003 John Wiley & Sons, Ltd.