bluuebunny/crossref_metadata_2025 huggingface dataset:
Activities of the Glycylcycline Tigecycline (GAR-936) against 1,924 Recent European Clinical Bacterial Isolates
Authors: Milatovic D. , Schmitz F.-J. , Verhoef J. , Fluit A. C.
Published: December 2002

The in vitro activities of tigecycline against 1,924 clinical isolates were examined. The new glycylcycline exhibited excellent activity against all gram-positive cocci (MICs at which 90% of the isolates tested were inhibited [MIC
90
s], ≤1 μg/ml). In addition, it was also very potent against most members of the
Enterobacteriaceae
, with most MIC
90
s being ≤2 μg/ml. Among the nonfermenters,
Acinetobacter
spp. and
Stenotrophomonas maltophilia
are included in the in vitro spectrum of tigecycline activity.
Activities of HMR 3787 and RU 64399 Compared with Those of Four Other Agents against
Haemophilus influenzae
and
Haemophilus parainfluenzae
Authors: Bozdogan Bülent , Clark Catherine , Bryskier Andre , Jacobs Michael R. , Appelbaum Peter C.
Published: December 2002

Activities of HMR 3787, a new 2-fluoroketolide, and its (des)-fluor derivative, RU 64399, were tested against 111
Haemophilus influenzae
and 26
H. parainfluenzae
strains and compared with those of telithromycin, erythromycin, azithromycin, and clarithromycin. HMR 3787 and RU 64399 MICs were comparable with those of azithromycin but were less affected by incubation in CO
2
. Time-kill studies of 12 strains showed that HMR 3787, RU 64399, and telithromycin were bactericidal against all strains after 24 h at two times the MIC.
Correlation of Phenotypic Zidovudine Resistance with Mutational Patterns in the Reverse Transcriptase of Human Immunodeficiency Virus Type 1: Interpretation of Established Mutations and Characterization of New Polymorphisms at Codons 208, 211, and 214
Authors: Stürmer Martin , Staszewski Schlomo , Doerr Hans-Wilhelm , Larder Brendan , Bloor Stuart , Hertogs Kurt
Published: December 2002

Zidovudine resistance (ZDV-R) is associated with classic genotypic changes at codons 41, 67, 70, 210, 215, and 219 of the human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) gene as well as with the multinucleoside resistance (MNR) complexes (Q151M MNR complex; 6-bp insertion/A62V complex). In addition, enhanced resistance to ZDV in the context of the classic ZDV mutations plus the M184V mutation has been associated with additional mutations at positions 208, 211, 214, and 333. In this study we investigated phenotypic ZDV-R determined by a recombinant virus assay (Antivirogram; Virco) in 223 clinical samples in relation to the above genotypic changes. 150 out of 223 clinical samples had the M184V mutation. Phenotypic ZDV-R ranged from 0.3- to 5,338-fold. Sixteen samples (15 with high ZDV-R ranging from 90- to 3,571-fold) contained MNR-associated patterns. Analysis of classic mutational patterns broadly demonstrated increasing ZDV-R with increasing number of ZDV mutations. A comparable correlation was obtained when ZDV-R was analyzed only relative to the T215Y/F mutation. Site-directed mutagenesis experiments investigating the influence of the additional mutations H208Y, R211K, and L214F on ZDV-R resulted in a 7.4- or 21-fold increase in ZDV-R when the R211K/L214F or H208Y/R211K/L214F mutations, respectively, were added to a highly ZDV-R virus. In the clinical sample data set we analyzed, the combination of R211K/L214F appeared most frequently. The H208Y change was detected only in highly ZDV-R viruses, whereas the G333E/D change was distributed equally. All changes were independent of the M184V mutation. A 2.4- or 8-fold increase in ZDV-R was observed in the clinical samples with high ZDV-R containing the R211K/L214F or H208Y/R211K/L214F mutations, respectively. We have shown that the combination of the additional mutations H208Y, R211K, and L214F in HIV-1 RT may influence ZDV-R and should be considered when assessing ZDV-R.
Susceptibility ofCandida dubliniensisto Salivary Histatin 3
Authors: Fitzgerald Deirdre H. , Coleman David C. , O'Connell Brian C.
Published: December 2002

Candida dubliniensisis a recently describedCandidaspecies associated with oral candidiasis in human immunodeficiency virus (HIV)-infected patients and patients with AIDS. The majority ofC. dubliniensisclinical isolates tested to date are susceptible to the commonly used antifungal drugs, including fluconazole, ketoconazole, itraconazole, and amphotericin B. However, the appearance of fluconazole-resistantC. dubliniensisstrains in this patient group is increasing. Histatins are a family of basic histidine-rich proteins present in human saliva which have therapeutic potential in the treatment of oral candidiasis. The mechanism of action of histatin is distinct from that of commonly used azole and polyene drugs. Characterization of the antifungal activity of histatin has mainly been carried out usingC. albicansbut it is also effective in killingC. glabrataandC. krusei. Here we report thatC. dubliniensisis also susceptible to killing by histatin 3. The concentration of histatin 3 giving 50% killing (the IC50value) ranged from 0.043 to 0.196 mg/ml among different strains ofC. dubliniensis. The least-susceptibleC. dubliniensisstrain, P9224, was found to internalize histatin at a lower rate than theC. albicansreference strain CA132A. The dissociation constant (Kd) for the least-susceptible strain (C. dubliniensis9224) was ninefold higher than that for theC. albicansreference strain. These results suggest that histatin 3 may have potential as an effective antifungal agent, particularly in the treatment of oral candidiasis in HIV-infected patients and patients with AIDS in which resistance to the commonly used antifungal drug fluconazole has emerged.
Occupational asthma from fungicides fluazinam and chlorothalonil
Authors: Draper A , Cullinan P , Campbell C , Jones M , Newman Taylor A
Published: December 2002

We report two cases of occupational asthma caused by sensitisation to powdered fungicides fluazinam and chlorothalonil, from the same fungicide formulation plant. Both developed work related lower respiratory symptoms after a latent interval of asymptomatic exposure. The diagnosis in each case was confirmed with a serial peak flow record in the workplace followed by specific inhalation tests. These fungicides are known to cause dermatitis; this report indicates that these compounds can induce specific immunological reactions in the airways as well as skin.
D2 dopamine receptor gene in psychiatric and neurologic disorders and its phenotypes
Authors: Noble Ernest P.
Published: December 2002

The D2 dopamine receptor (DRD2) has been one of the most extensively investigated gene in neuropsychiatric disorders. After the first association of the TaqI A DRD2 minor (A1) allele with severe alcoholism in 1990, a large number of international studies have followed. A meta‐analysis of these studies of Caucasians showed a significantly higher DRD2 A1 allelic frequency and prevalence in alcoholics when compared to controls. Variants of the DRD2 gene have also been associated with other addictive disorders including cocaine, nicotine and opioid dependence and obesity. It is hypothesized that the DRD2 is a reinforcement or reward gene. The DRD2 gene has also been implicated in schizophrenia, posttraumatic stress disorder, movement disorders and migraine. Phenotypic differences have been associated with DRD2 variants. These include reduced D2 dopamine receptor numbers and diminished glucose metabolism in brains of subjects who carry the DRD2 A1 allele. In addition, pleiotropic effects of DRD2 variants have been observed in neurophysiologic, neuropsychologic, stress response, personality and treatment outcome characteristics. The involvement of the DRD2 gene in certain neuropsychiatric disorders opens up the potential of a targeted pharmacogenomic approach to the treatment of these disorders. © 2003 Wiley‐Liss, Inc.
Positive association of the AMPA receptor subunit GluR4 gene (GRIA4) haplotype with schizophrenia: Linkage disequilibrium mapping using SNPs evenly distributed across the gene region
Authors: Makino Chieko , Fujii Yo , Kikuta Rumiko , Hirata Naotsugu , Tani Ayako , Shibata Atsushi , Ninomiya Hideaki , Tashiro Nobutada , Shibata Hiroki , Fukumaki Yasuyuki
Published: December 2002

The glutamatergic dysfunction hypothesis suggests that genes involved in the glutamate neurotransmitter system are candidates for schizophrenia‐susceptibility genes. We have been conducting systematic studies of the association between glutamate receptors and schizophrenia. We report on a positive association of some haplotypes of the AMPA receptor subunit GluR4 gene (GRIA4) with schizophrenia. We genotyped 100 Japanese schizophrenics and 100 controls for six single nucleotide polymorphism (SNP) markers distributed at intervals of about 50 kb in the GRIA4 region, and estimated the degree of linkage disequilibrium (LD) between the SNPs. We constructed haplotypes of the SNPs in LD using the EM algorithm to test their association with schizophrenia. Significant associations were detected for the combination of SNP4‐5 (χ2 = 12.54, df = 3, P = 0.0057, P = 0.029 with Bonferroni correction) and for the combination of SNP3‐4‐5 (χ2 = 18.9, df = 7, P = 0.0085, P = 0.043 with Bonferroni correction). These results suggest that at least one susceptibility locus for schizophrenia is located within or very close to the GRIA4 region in Japanese. © 2003 Wiley‐Liss, Inc.
Polymorphism screening of PIK4CA: Possible candidate gene for chromosome 22q11‐linked psychiatric disorders
Authors: Saito Takuya , Stopkova Pavla , Diaz Libna , Papolos Demitri F. , Boussemart Lise , Lachman Herbert M.
Published: December 2002

Lithium is potent non‐competitive inhibitor of an enzyme involved in the metabolism of phosphatidylinositol 4,5‐bisphosphate (PtdIns‐4,5‐P2), a critical phosphoinositide (PI) that regulates signal transduction and synaptic vesicle function. Interestingly, a number of genes involved in the regulation of PtdIns‐4,5‐P2 synthesis and dephosphorylation are found in regions of the genome previously mapped in bipolar disorder (BPD) including 10p, 18q, 21q, and 22q. One is PIK4CA, a member of the phosphatidylinositol 4‐kinase family that phosphorylates PtdIns at the D4 position of the inositol ring as part of the PtdIns‐4,5‐P2 synthetic pathway. PIK4CA maps to 22q11 in a region believed to contain a susceptibility gene for psychiatric disorders. Screening of two functional domains of PIK4CA and the promoter region resulted in the identification of 15 different polymorphisms. Rare variants at a consensus splice donor site and the promoter region were found in a total of three patients with BPD, three with schizophrenia (SZ) and only one control. Several common non‐synonymous changes and a common single nucleotide polymorphism (SNP) at position −31 in the putative promoter were identified and analyzed in patients with BPD, SZ, and controls. There was no difference in the allele distribution in mentally ill subjects and controls for two variants, R2259C and E2079Q, both located in the PIK4CA catalytic domain. There was, however, a trend toward significance in the distribution of the −31 promoter genotypes in bipolar subjects and controls. Although the results of this analysis were modest, considering the heterogeneity of BPD and SZ and the hypothesis that BPD may be caused by abnormalities in genes that regulate PI‐mediated phenomena in the brain, the polymorphisms we detected in the PIK4CA gene should be analyzed in a larger data set to help determine their significance in 22q11‐linked mental disorders. © 2002 Wiley‐Liss, Inc.
Lack of association between serotonin 5‐HT1B receptor gene polymorphism and suicidal behavior
Authors: Rujescu Dan , Giegling Ina , Sato Tetsuya , Möller Hans‐Jürgen
Published: December 2002

A genetic susceptibility to suicide attempts has been repeatedly suggested by family‐, twin‐, and adoption‐studies. Because elevated impulsive aggression is one of the most prominent characteristics of suicide attempters and aggressive behavior has been reported in 5‐HT1B receptor gene knockout mice, the serotonin receptor 1B gene (5‐HT1B) is an attractive candidate. The distribution of a polymorphism (G861C) in the 5‐HT1B gene was examined in 148 consecutively hospitalized German suicide attempters, and 327 German healthy volunteers randomly recruited from the general population. The controls and their first degree relatives had no history of mental disorders or suicidal behavior. We found no significant difference in allele or genotype frequency between patients and controls. The results did not differ when the patients were divided into several subgroups (gender, suicide attempters with a violent method or suicide attempters with unipolar‐, bipolar‐, borderline personality‐, and schizophrenia spectrum disorders). These findings suggest that the 5‐HT1B polymorphism is unlikely to play a major role in the genetic susceptibility to suicide attempts. © 2002 Wiley‐Liss, Inc.
No association between non‐violent suicidal behavior and the serotonin transporter promoter polymorphism
Authors: Courtet Philippe , Buresi Catherine , Abbar Mocrane , Baud Patrick , Boulenger Jean‐Philippe , Castelnau Didier , Mouthon Dominique , Malafosse Alain
Published: December 2002

There is compelling evidence that suicidal behavior is associated with the dysfunction of the serotonin system. A functional polymorphism in the promoter region of the serotonin transporter gene (5‐HTTLPR) was recently identified and the presence of the short allele was associated with lower gene expression, lower 5‐HT uptake and violent suicidal behavior. Thus, we attempted to determine whether 5‐HTTLPR is also involved in the susceptibility to non‐violent suicidal behavior. We compared the genotype from 166 West European Caucasians who attempted suicide by a non‐violent mean with 139 controls with no history of suicidal behavior from the same ethnic origin. The frequencies of the S allele and the SS genotype in the sample who attempted non‐violent suicide were not statistically different to those in the controls. Thus, the genetically altered expression of the 5‐HT transporter might be associated with more severe or violent suicidal behavior, but not with non‐violent suicidal behavior. © 2002 Wiley‐Liss, Inc.
Fine mapping of an isodicentric Y chromosomal breakpoint from a schizophrenic patient
Authors: Yoshitsugu Kiyoshi , Meerabux Joanne M.A. , Asai Kunihiko , Yoshikawa Takeo
Published: December 2002

We report on a male schizophrenic patient who carried an isodicentric Y chromosome [idic(Y)] with a mosaic karyotype [mos 45,X/46,X,idic(Y)(q11)]. Although a potential association between sex chromosome abnormalities and a susceptibility to psychoses has been documented, there has only been one previous report of idic(Y) coincident with schizophrenia. The [45,X] karyotype is known to be associated with Turner syndrome (TS), but our patient lacked most of the phenotypic features of TS, except for short stature. To define the precise position of the breakpoint on the patient's abnormal Y chromosome, we carried out polymerase chain reaction (PCR) analysis, using primers for 15 marker loci along the chromosome. The breakpoint was localized to between the marker loci sY118 and sY119 on Yq in the 5M interval of the deletion map. This position represents the most centromeric breakpoint recorded for idic(Y). We cannot exclude the possibility that the development of schizophrenia is unrelated to the Y chromosome abnormality in this patient but we hope that this study will stimulate further cytogenetic and molecular genetic analyses of Y chromosome regions that may influence psychiatric traits. © 2002 Wiley‐Liss, Inc.
Evaluation of fluorescent dyes for measuring intracellular glutathione content in primary cultures of human neurons and neuroblastoma SH‐SY5Y
Authors: Sebastià Jordi , Cristòfol Rosa , Martín Manuela , Rodríguez‐Farré Eduard , Sanfeliu Coral
Published: December 2002

Background

Reduced glutathione (GSH) protects cells against oxidative injury and maintains a range of vital functions. To study GSH content in human neuronal cell cultures, thiol‐sensitive fluorescent techniques requiring a small number of cells may be of great value, but their GSH specificity has not been established in these cells.

Methods

We tested the efficiency of four currently available GSH fluorescent stains in human neurons and SH‐SY5Y neuroblastoma cells, both cultured in microwells, by using a fluorescence plate reader. Cultures were treated with the inhibitor of the GSH synthesis, buthionine sulfoximine (BSO), and progressive GSH depletion was assayed with monochlorobimane (mBCl), monobromobimane (mBBr), 5‐chloromethylfluorescein diacetate (CMFDA), and 7‐amino‐4‐chloromethylcoumarin (CMAC). GSH was also determined by a biochemical method in cell homogenates to obtain quantitative reference values.

Results

Neurons and SH‐SY5Y neuroblastoma had basal GSH contents of 27.1 ± 3.2 and 14.5 ± 1.7 nmol/mg protein (n = 5), respectively. An approximate 90% depletion of GSH was obtained after 3 days of exposure to 1,000 μM of BSO in neurons and after 1 day in SH‐SY5Y cells. Cell death through an apoptotic pathway appeared 1–2 days after total GSH depletion. The assayed stains had different degrees of background fluorescence and sensitivity to GSH content, with similar results in both neuronal cell types. The probes mBCl and CMAC showed the lowest background, and the GSH‐depletion curves were most similar to that of the reference method.

Conclusions

Both mBCl and CMAC are useful fluorescent stains to determine semiquantitative GSH concentration in human neuronal cell cultures. Cytometry Part A 51A:16–25, 2003. © 2002 Wiley‐Liss, Inc.
Guess what: Chronic 13q14.3+/CD5−/CD23+ lymphocytic leukemia in blood and t(11;14)(q13;q32)+/CD5+/CD23− mantle cell lymphoma in lymph nodes!
Authors: Lima Margarida , Pinto Luísa , Dos Anjos Teixeira Maria , Canelhas Áurea , Mota Alexandra , Cabeda José Manuel , Silva Cidália , Queirós Maria Luís , Fonseca Sónia , Santos Ana Helena , Brochado Paulo , Justiça Benvindo
Published: December 2002

We report a case of a patient with two B‐cell lymphoproliferative disorders: CD5−/CD23+ B‐cell chronic lymphocytic leukemia and CD5+/CD23− mantle cell lymphoma. These disorders were diagnosed simultaneously based on flow cytometry, immunohistochemistry, fluorescence in situ hybridization, and polymerase chain reaction–based molecular studies. The B‐cell lymphocytic leukemia clone predominated in the blood and bone marrow, whereas the mantle cell clone predominated in lymph nodes. Cytometry Part B (Clin. Cytometry) 51B:41–44, 2003. © 2002 Wiley‐Liss, Inc.
Increases in adipose and total body weight, but not in lean body mass, associated with subcutaneous administration of Sonic hedgehog‐Ig fusion protein to mice
Authors: Martin Pauline L. , Lane Joan , Pouliot Louise , Gains Malcolm , Stejskal Rudolph , Smith Susan Yvonne , Galdes Alphonse , Green James
Published: December 2002

Sonic hedgehog (Shh) is a member of a family of proteins that are involved in embryonic development. The receptor signaling pathways for Shh persist in adults and stimulation of this pathway has shown therapeutic efficacy in animal models of neurodegeneration/regeneration. This study was conducted to evaluate the safety of repeat dose administration of an IgG fusion protein of Shh (Shh‐Ig) in adult mice. Routine toxicology evaluations were performed. In addition, body composition analysis was conducted by densitometry. Shh‐Ig treatment caused a significant increase in body weight gain relative to controls and a slight increase in liver and spleen weights. The increase in body weight could be largely accounted for by an increase in body fat. The treatment‐related increases in body weight were reversible upon cessation of treatment. Shh‐Ig treatment produced no significant changes in clinical chemistry or hematology. There were no gross or histomorphologic findings in any tissue except for skin and spleen. Microscopic findings in the skin were limited to minimal to slight local epidermal hyperplasia at the sc injection site and increased thickness of the fat layer. In the spleen a slight increase in extramedullary hematopoiesis was seen. This finding is possibly a secondary response following inflammation at the injection site in some animals due to the administration of a foreign protein. This study showed that Shh‐Ig administration was well tolerated. The most significant finding was a reversible increase in body weight. Drug Dev. Res. 57:107–114, 2002. © 2002 Wiley‐Liss, Inc.
Osteoblastic differentiation of mesenchymal stem cells by mumie extract
Authors: Jung Cho‐Rok , Schepetkin Igor A. , Woo Sang B. , Khlebnikov Andrei I. , Kwon Byoung S.
Published: December 2002

Mumie, a plant humus matter from rocks, is known as anabolic and a stimulator of bone regeneration in the Russian and Indian systems of health and medicine. The water‐soluble fraction of mumie from Uzbekistan was characterized using 1H NMR and infrared spectroscopic methods. The mumie extract has been investigated for its effect on osteoblastic differentiation in cell culture assays of human and murine mesenchymal stem cells. The calcium deposition and expression of alkaline phosphatase, osteocalcin, core binding factor 1 (Cbfa1), and ERK have been studied. During the 14‐day assay period, human bone marrow mesenchymal stem cells (hMSCs) and human fetal osteoblasts cultured with mumie (3–5 µg/ml) underwent a dramatic change in cellular morphology, which was accompanied by a significant increase in alkaline phosphatase activity, calcium deposition, and osteocalcin expression. The expression of core binding factor 1 and ERK were enhanced in hMSCs and murine pluripotent mesenchymal precursor cell line C2C12. Dose‐dependent decrease in TRAP‐positive multinucleated cell formation from macrophage‐like cells RAW 264.7 was observed with increasing concentration of mumie in the presence of RANKL (40 ng/ml) and PD98059 (10 µM), a specific inhibitor of ERK activity. The data suggest that mumie is a potent stimulator of osteoblastic differentiation of mesenchymal stem cells and inhibitor of osteoclastogenesis, hence it maybe of clinical benefit in the treatment for osteoporosis in human. Drug Dev. Res. 57: 122–133, 2002. © 2002 Wiley‐Liss, Inc.
Night time eating: a review of the literature
Authors: de Zwaan Martina , Burgard Melissa A. , Schenck Carlos H. , Mitchell James E.
Published: December 2002

This study reviews the published research on night time eating, including the night eating syndrome (NES) and the nocturnal eating/drinking syndrome (NEDS). Studies were identified by a computerized literature search (PubMed, PsycInfo) and by references from the papers obtained. In addition, published abstracts from recent conferences in the areas of eating disorders and obesity were included. Individual studies were reviewed and their results summarized. Wakeful night time eating appears to be a frequent symptom which is more common among the obese. The data suggest an early age of onset with a chronic course in many patients. There appears to be considerable overlap between NES and NEDS. Treatment studies are sparse. The clinical features of these syndromes, their comorbidities, and their prevalence rates remain a matter of debate. It is unclear if the night eating syndrome presents a distinct entity that is of clinical relevance. The current nosologies may not capture the natural clustering of eating and sleep‐related pathology as it occurs in general population samples. Copyright © 2003 John Wiley & Sons, Ltd and Eating Disorders Association.
Geoarchaeological contexts for Late Pleistocene archaeological sites with human‐modified woolly mammoth remains in southeastern Wisconsin, U.S.A.
Authors: Overstreet David F. , Kolb Michael F.
Published: December 2002

This paper defines the geomorphic and stratigraphic contexts, and site formation processes for the Hebior and Schaefer woolly mammoths in southeastern Wisconsin. Both mammoths were butchered, and there are artifacts associated with the faunal remains. Radiocarbon ages obtained from purified mammoth bone collagen range between 12,200 and 12,600 yr B.P. for the Schaefer and Hebior mammoths and between 13,440 and 13,510 yr B.P. for the nearby Mud Lake and Fenske mammoths. These ages indicate human use of an ice marginal landscape 1000–2000 years before human–mammoth interaction in the American southwest. They also indicate these sites are pre‐Clovis in age and may be associated with the recently defined non‐Clovis Paleoindian variant called the Chesrow complex. Chesrow complex sites are located on glacial lake and moraine features or in deposits that are of similar ages as the butchered mammoths, but they have not been unequivocally linked to the mammoth sites. Geomorphic and stratigraphic data were collected from profiles in archaeological excavations and backhoe trenches, and from cores. The Hebior and Schaefer sites lie in a topographic low between two end moraines. Mammoths remains rest on deglacial deposits and are encased in the post‐glacial deposits. At Hebior, these deposits consist of glaciolacustrine clays overlain by a thin stratum of glaciofluvial sands, on which the bones rest, overlain by laminated peat and muck. Sills and dikes of sand cross‐cut the organic deposits and formed late in the depositional sequence. At the Schaefer site, the bone pile rests on glaciolacustrine clays and is encased in clastic pond deposits and laminated peat and muck. Contextual analysis indicates the bone piles arein situand were preserved initially by inundation in ponds and subsequently by organic deposition in wetlands. Radiocarbon ages, stratigraphic/geomorphic contexts, and taphonomic studies indicate the Hebior and Schaefer mammoths arein situevidence for human interaction with megafauna very near the active glacial ice margin in the mid‐continent by 12,500 yr B.P. and perhaps as early as 13,500 yr B.P. © 2003 Wiley Periodicals, Inc.
Dating the Lindenmeier Folsom site, Colorado, U.S.A., before the radiocarbon revolution
Authors: Haynes C. Vance
Published: December 2002

Determining the age of the Lindenmeier Folsom site a decade before the advent of radiocarbon dating required the combined application of stratigraphy, geomorphology, and glacial chronology as well as archaeology. Eventually, radiocarbon dating at the site proved the estimates to be remarkably close to the true age. This paper summarizes Kirk Bryan and Louis L. Ray's efforts during the 1930s and early 1940s to determine the age of the Folsom horizon at Lindenmeier, and compares their relative chronology with the radiocarbon chronology established by others and myself for the site. © 2003 Wiley Periodicals, Inc.
Macrotricyclic quaternary tetraammonium receptors: Halide anion recognition and interfacial activity at an aqueous interface. A molecular dynamics investigation
Authors: Chaumont Alain , Wipff Georges
Published: December 2002

We report a molecular dynamics study of the halide inclusion complexes X− ⊂ L4+ of a macrotricyclic tetrahedral receptor L4+ built from four quaternary ammonium sites connected by six (CH2)n chains. The hydrophilic/hydrophobic character of the complexes is investigated at a water/chloroform interface, represented explicitly and, despite their +3 charge and “spherical” shape, they are found to display amphiphilic behavior and to concentrate at the interface. The more lipophilic N‐substituted CH2ϕ derivative, as well as less charged models are more surface active than the N‐Me substituted host. In relation with the Hofmeister series, I−
exo neutralizing counterions are compared with Cl− anions and are found to sit closer to the interface, which becomes more neutral. The “macrocyclic interfacial effect” is investigated by a comparison of L4+ complexes with their acyclic counterparts. Finally, we address the question of anion binding selectivity by L4+ and its L and L topological isomers. F− is too small for these three hosts, while I− is too big. According to free energy perturbation calculations, Cl− is preferred to Br−, but somewhat more by L than by L4+. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1532–1543, 2002
Helix motion in protein C12A‐p8MTCP1: Comparison of molecular dynamics simulations and multifield NMR relaxation data
Authors: Barthe Philippe , Roumestand Christian , Déméné Hélène , Chiche Laurent
Published: December 2002

The human p8MTCP1 protein is constituted by an original disulfide bridged α‐hairpin motif, and a third hydrophilic helix that appeared mobile and independent in NMR analysis. To get atomic scale description of the possible motions involved, a 12‐ns molecular dynamics simulation of the C12A‐p8MTCP1 mutated protein and 10 400‐ps simulations were performed in explicit water at 298 K. Analyses of the essential dynamics subspace and of the time‐evolution of secondary structures indicate large displacements and internal motions of the third helix. Simulated order parameters, S,2 are consistent to those obtained from 15N‐NMR relaxation data recorded at five different magnetic fields (proton resonance frequencies: 400, 500, 600, 700, and 800 MHz). The simulations show a fairly rigid α‐hairpin motif with only very small local conformational changes, although the loop between helices undergoes significant correlated motions. The displacements and internal motions of the third helix can be essentially accounted for by α‐helical to 310‐helical transitions near its N‐terminus and by a hinge‐bending motion near glycine 52. The loss of the α‐helical conformation for a large part of the third helix during about 25% of the simulation time supports the possible occurrence of a slow motion as suggested by previous analyses of the 3JNH‐Hα coupling constant values and of the proton‐deuterium NH exchange kinetics. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1577–1586, 2002
Ultrastructure of endothelial cells under flow alteration
Authors: Masuda Hirotake , Kawamura Koichi , Nanjo Hiroshi , Sho Eiketsu , Komatsu Masayo , Sugiyama Tatsuo , Sugita Akihiro , Asari Yasushi , Kobayashi Mikio , Ebina Toshihito , Hoshi Naoto , Singh Tej M. , Xu Chengpei , Zarins Christopher K.
Published: December 2002

Endothelial cells are stable and quiet in normal animals. They arrange regularly and have a smooth lumen surface and thin endothelial wall. According to Thoma's principle (1893) and Kamiya and Togawa's principle (1980) on the relationship of the vascular diameter to flow alteration, blood flow is in equilibrium to the diameter and in a physiological state. That is to say, there is no fast flow or slow flow. To understand the nature of the endothelial cells, we should investigate endothelial cells under flow alteration to break the equilibrium state. Endothelial cells under increased flow were studied in arteries with an arteriovenous fistula or in the capillaries of myocardium with volume‐overloaded hearts or of the skeletal muscle by electrical stimulation. Those under decreased flow were studied by the closure of the fistula or by ceasing the stimulation. Endothelial cells in the coarctation of the arteries were also observed. Endothelial cells were activated by increased flow in the arteries and capillaries, while they were inactivated by decreased flow. Endothelial activation is characterized as lumen protrusions, increase of cytoplasmic organelles, abluminal protrusions, basement membrane degradation, internal elastic lamina degradation in the arteries, and sproutings in the capillaries. These are ultrastructurally comparable to angiogenesis. Endothelial inactivation is characterized by the decrease of endothelial cell number with apoptosis, which is ultrastructurally comparable to angioregression. We assume that endothelial cells respond to increased flow by angiogenesis and to decreased flow by angioregression. Microsc. Res. Tech. 60:2–12, 2003. © 2002 Wiley‐Liss, Inc.
Vascular wall: Potential target for the physicochemical effects of cis‐unsaturated free fatty acids
Authors: Pérez Francisco R. , Piñeiro Verónica , De La Cruz Luis F. , Casanueva Felipe F. , Casabiell Xesús
Published: December 2002

Diets rich in monounsaturated cis‐FFA (cis FFA) are associated with a significant reduction of cardiovascular risk. Although several different mechanisms have been proposed to explain this protective effect, the biochemical processes involved have not been fully elucidated. It has been shown that upon their incorporation into the plasma membrane, cis FFA induce a marked perturbation of the lipid domains, altering membrane fluidity as well as lipid–lipid and lipid–protein interactions in the bilayer plane. During the last few years, several lines of evidence have shown that these perturbations disrupt the activity of several membrane proteins and enzymatic systems. As a result, several critical transmembrane signaling systems, including the Ins(1,4,5)P3/DAG/[Ca2+]i, the cAMP/PKA, and the voltage‐operated Ca2+ influx are strongly inhibited by cis FFA in different experimental models. Furthermore, this inhibition is associated with alterations in the timing of the cell cycle as well as in the final steps of the secretory pathway. We propose that this complex set of biological actions exerted by cis FFA at the plasma membrane may contribute to explain the protective roles that these molecules appear to exert on the vascular wall. Microsc. Res. Tech. 60:23–29, 2003. © 2002 Wiley‐Liss, Inc.
Diffusion‐weighted MRI after cryosurgery of the canine prostate
Authors: Butts Kim , Daniel Bruce L. , Chen Lili , M. Bouley Donna , Wansapura Janaka , Maier Stephan E. , Dumoulin Charles , Watkins Ron
Published: December 2002

Purpose

To evaluate the acute lesion created by cryosurgery with diffusion‐weighted magnetic resonance imaging (DWI).

Materials and Methods

The appearance of the acute cryolesion was evaluated in four canine prostates DWI after they were warmed to original body temperature. The prostates were excised, stained with triphenyl tetrazolium chloride (TTC), photographed, prepared for hematoxylin and eosin (H&E) staining, and examined under a light microscope.

Results

A marked decrease in apparent diffusion coefficient of 38% was evident in the center of the previously frozen tissue, but not in all of the previously frozen tissue. Histologic results confirm differences between the iceball core and the periphery of the iceball, which have markedly different imaging characteristics on DWI.

Conclusion

The core of the previously frozen tissue has a reduced apparent diffusion coefficient (ADC) compared to the periphery of the previously frozen tissue and previously unfrozen tissue. J. Magn. Reson. Imaging 2003;17:131–135. © 2002 Wiley‐Liss, Inc.
Kinetics of the thermal decomposition of bis(trifluoromethyl) peroxydicarbonate, CF3OC(O)OOC(O)OCF3
Authors: Burgos Paci Maximiliano A. , Argüello Gustavo A. , García Plácido , Willner Helge
Published: December 2002

Thermal decomposition of bis(trifluoromethyl) peroxydicarbonate has been studied. The mechanism of decomposition is a simple bond fission, homogeneous first‐order process when the reaction is carried out in the presence of inert gases such as N2 or CO. An activation energy of 28.5 kcal mol−1 was determined for the temperature range of 50–90°C. Decomposition is accelerated by nitric oxide because of a chemical attack on the peroxide forming substances different from those formed with N2 or CO. An interpretation on the influence of the substituents in different peroxides on the OO bond is given. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 35: 15–19, 2003
Purchase‐role structure in Korean families: Revisited
Authors: Na Woonbong , Son Youngseok , Marshall Roger
Published: December 2002

This opportunistic research has been made possible by the financial crisis that struck much of Asia in 1998, and was followed by a rapid recovery in 1999. Previous research has been conducted to study the structure of family decisions in Korea during the 1997–98 period. By adding one more set of data points, for 1999, it is possible to conduct a 3‐year, longitudinal study to revisit the structure of family decision making under the impact of the economic crisis experienced during this period. The major finding is that more joint decision making occurs under economic stress, although the effect is mitigated by the economic circumstances of the respondent and involvement level of the product category. © 2003 Wiley Periodicals, Inc.
A study of Japanese consumers' cognitive hierarchies in formal and informal gift‐giving situations
Authors: Lotz Sherry L. , Shim Soyeon , Gehrt Kenneth C.
Published: December 2002

In recent years, academicians have shown an increasing interest in Asian gift‐giving behavior. Yet studies investigating Asians' cognitive hierarchical structures in the gift‐giving context have been limited. Additionally, the literature suggests that Asian consumers' cognitive structures are particularly affected by situational contingencies. Thus, this study examines Japanese consumers' cognitive hierarchies, in a gift‐giving context, in formal and informal situations utilizing a most‐abstract to least‐abstract cognitive hierarchical framework. Data were collected through a mail survey of Japanese consumers in the greater Tokyo area and six other major metropolitan cities. As hypothesized, structural‐equation modeling results revealed that the Japanese consumer's cognitive hierarchical flow from most‐ to least‐abstract cognitions remained intact regardless of the situation. In contrast, as expected, differing situations were found to influence intercognitive dimensional relationships. Implications of these findings are discussed. © 2003 Wiley Periodicals, Inc.
Protective effects of ligustrazine on ischemia‐reperfusion injury in rat kidneys
Authors: Sun Lijiang , Li Yujun , Shi Jingsen , Wang Xiao , Wang Xiang
Published: December 2002

To investigate the protective effects of ligustrazine on renal ischemia‐reperfusion injury, the influence of ligustrazine injection on plasma superoxide dismutase (SOD), malondialdehyde (MDA), and endothelin‐1 (ET‐1), as well as changes of morphology of renal tubules, were studied in rat kidney models with ischemia‐reperfusion injury. The results showed that in the group treated with ligustrazine, the plasma SOD level was significantly higher than that of the control group (P < 0.05), but levels of plasma MDA and ET‐1 and the pathological grading of injured renal tubules were significantly lower than those in the control group (P < 0.05). These findings suggest that ligustrazine has protective effects against ischemia‐reperfusion injury in rat kidneys. © 2002 Wiley‐Liss, Inc. MICROSURGERY 22:343–346 2002
Independent roles of Rho‐GTPases in growth cone and axonal behavior
Authors: Thies Edda , Davenport Roger W.
Published: December 2002

Many external signals influence growth cone motility, pathfinding, and the formation of synapses that lead to the final map formation of the retinotectal system. Chick temporal retinal ganglion cell axons (RGCs) collapse and retract after encountering posterior tectal cells in vitro. During this process lateral extensions appear along the RGC axonal shaft. Lateral extensions appear as nascent interstitial axonal branches and also as defasciculating growth cones that are trailing along the pioneer axon. RGC branching controlled by repellent tectal cues has recently been shown to be the critical event in retinotectal map development. The intracellular mechanism underlying this phenomenon, however, is not understood. Inhibiting RhoA with either C3 toxin or inhibiting p160Rock kinase, an effector of RhoA, with Y27632 inhibited collapse, retraction, and the number of axons that showed lateral extensions. Lateral extension length increased significantly. Inhibiting Rac1A and cdc42 with cell permeable peptide inhibitors did not inhibit collapse of growth cones, but did inhibit axon retraction. In addition, the number of axons that showed lateral extensions and lateral extension length were significantly reduced. A dynamic cytoskeleton is necessary to react to incoming guidance information. This study addresses the problems of how growth cone motility and branching or defasciculation are affected by Rho‐GTPases as extracellular signals are transmitted to the cytoskeleton. © 2002 Wiley Periodicals, Inc. J Neurobiol 54: 358–369, 2003
Preconditioning methods for linear systems arising in constrained optimization problems
Authors: Axelsson Owe , Neytcheva Maya
Published: December 2002

Preconditioning methods for matrices on saddle point form, as typically arising in equality constrained optimization problems, are surveyed. Special consideration is given to two methods: a nearly symmetric block incomplete factorization preconditioning method and a preconditioner on the same saddle point form as the given matrix. Both methods result in eigenvalues with positive real parts and small or zero imaginary parts. The behaviour of the methods are illustrated by solving a regularized Stokes problem. Copyright © 2002 John Wiley & Sons, Ltd.
Biospinning: Change of water contents in drawn silk
Authors: Tanaka Toshihisa , Kobayashi Masatoshi , Inoue Shun‐Ichi , Tsuda Hidetoshi , Magoshi Jun
Published: December 2002

Changes of the water content in drawn silk during drying were investigated by thermal analysis and 1H pulse NMR. Water in liquid silk by drawing extruded from the inside of the silk filament into ambient air. The water contents in the drawn silk decreased with drying time. Assuming the nonfreezing water has a concentration of 10 wt % in the liquid silk, the percentage distribution of water in liquid silk is composed of 10 wt % nonfreezing water, 40 wt % freezing water, and 30 wt % free water. This 40 wt % freezing water in the liquid silk may be important for the formation of fine pores on the surface of drawn silk. The apparent pore radius, which was calculated from the results of thermal analysis, on the surface of drawn silk decreased to 5.0 nm and finally to 2.0 nm. The calculated apparent fine pore formed on the surface by drawing was 4.0 nm. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 274–280, 2003
From nationwide standardized testing to school‐based alternative embedded assessment in Israel: Students' performance in the matriculation 2000 project
Authors: Dori Yehudit J.
Published: December 2002

Matriculation 2000 was a 5‐year project aimed at moving from the nationwide traditional examination system in Israel to a school‐based alternative embedded assessment. Encompassing 22 high schools from various communities in the country, the Project aimed at fostering deep understanding, higher‐order thinking skills, and students' engagement in learning through alternative teaching and embedded assessment methods. This article describes research conducted during the fifth year of the Project at 2 experimental and 2 control schools. The research objective was to investigate students' learning outcomes in chemistry and biology in the Matriculation 2000 Project. The assumption was that alternative embedded assessment has some effect on students' performance. The experimental students scored significantly higher than their control group peers on low‐level assignments and more so on assignments that required higher‐order thinking skills. The findings indicate that given adequate support and teachers' consent and collaboration, schools can transfer from nationwide or statewide standardized testing to school‐based alter‐native embedded assessment. © 2003 Wiley Periodicals, Inc. J Res Sci Teach 40: 34–52, 2003
An adaptive space–time receiver for high‐capacity communications systems based on multichannel multirate DS‐CDMA
Authors: Falletti Emanuela , Sellone Fabrizio , Tortorelli Innocenzo
Published: December 2002

The capacity of wireless communications systems based upon Direct‐Sequence Code Division Multiple Access (DS‐CDMA) is severely reduced by Multiple Access Interference (MAI), especially at higher bit rates. Therefore, methods aimed at limiting the MAI are mandatory solutions in order to face the ever‐growing number of subscribers of next‐generation wireless systems. Smart Antennas are a promising technology for improving the performance of high‐capacity mobile communications systems, because they are able to increase the Signal to Interference plus Noise power Ratio (SINR) of the received signals by dynamically adapting the equivalent array beam pattern in order to track the movements of the users within the cell. Moreover, Spatiotemporal RAKE receivers, representing the synergy between beamforming techniques and RAKE receiver structures, are one of the best candidates for the realization of high‐capacity multichannel (CDMA) wireless systems, due to their ability in exploiting both the spatial and temporal diversity inherently offered by wireless channels.

This paper is focused on the structure of a Spatiotemporal RAKE receiver for the uplink of multichannel DS‐CDMA systems. Its main feature is the capability of coherently combining the multipaths of the useful signal across both space and time, while simultaneously reducing the MAI. A blind and adaptive beamforming algorithm realizing such a Spatiotemporal RAKE receiver is presented. It exploits the knowledge and the synchronization of the scrambling code uniquely assigned to an addressed user, requiring neither estimates of the spatiotemporal propagation channel nor training or pilot sequences. Its design philosophy consists in the maximization of the SINR at the beamformer output, and it is based upon an orthogonal projection of the received signal onto the linear space generated by the spreading code of the desired user.

Computer simulations show the effectiveness of the Spatiotemporal receiver, in terms of convergence speed, SINR gain and bit error probability. Copyright © 2002 John Wiley & Sons, Ltd.
A novel class of decimation filters for ΣΔ A/D converters
Authors: Daneshgaran Fred , Laddomada Massimiliano
Published: December 2002

A major bottleneck to the design of a truly wideband reconfigurable Software Radio (SR) transceiver is the front end of the system. It is desirable to push the analog‐to‐digital boundary of the SR transceiver as close to the antenna as possible. This places great demands on analog‐to‐digital converters that must produce high‐resolution samples of the incoming signal centered around a carrier frequency in the gigahertz range. A very promising architecture for the design of such converters is the ΣΔ architecture. A critical component of the ΣΔ converter is the rate‐conversion filter that is responsible for rejection of the out‐of‐band noise. Cascaded‐Integrator‐Comb (CIC) filters are efficient antialiasing rate‐conversion filter structures realized by cascading integrator and comb cells separated by a decimation block. High‐order structures, attempting to increase the rejection of the out‐of‐band noise that folds into the useful signal bandwidth because of the decimation, have the drawback of inserting multiple zeroes in the same positions throughout the stop‐band and to increase the edge‐band attenuation.

In this paper, we propose a class of decimation filter architectures composed of a cascade of modified CIC filters, which have higher attenuation of the quantization noise produced by a ΣΔ modulator around the folding bands and lower passband drop than classic CIC structures. The design criteria of the proposed filters are described, with the goal of maximizing the denoising effect and minimizing the passband drop, and the problem of the practical realization of the proposed decimation scheme is addressed. Simulations confirm the effectiveness of the proposed decimation filter architectures. Copyright © 2002 John Wiley & Sons, Ltd.