bluuebunny/crossref_metadata_2025 huggingface dataset:
First‐trimester diagnosis of hydrolethalus syndrome in a Chinese family
Authors: Chan Ben Chong Pun , Shek Tony Wai Hung , Lee Chin Peng
Published: August 2004

We report a case resembling hydrolethalus syndrome in a Chinese family. Fetal polydactyly, syndactyly, encephalocele and cardiac malformation were detected on ultrasound examination at 12 weeks' gestation. Termination of pregnancy was performed, and postmortem examination confirmed the findings. This is the first report of a first‐trimester prenatal diagnosis of hydrolethalus syndrome in the Chinese population. Copyright © 2004 John Wiley & Sons, Ltd.
The impact of fetal renal pelvic diameter on postnatal outcome
Authors: John Ulrike , Kähler Christiane , Schulz Sven , Mentzel Hans Joachim , Vogt Susanna , Misselwitz Joachim
Published: August 2004

Objectives

To determine thresholds for the fetal renal pelvic anterior–posterior diameter (APD) predicting postnatal clinically relevant pelvicaliceal dilatation.

Methods

One hundred and forty‐eight infants whose prenatal sonography had identified an isolated uni‐ or bilateral fetal APD of ≥4 mm before 33 and/or ≥7 mm after 33 weeks' gestational age were investigated postnatally. On the basis of postnatal ultrasound examination, these infants were grouped according to the Society for Fetal Urology Grading System: no pelvic dilatation (n = 38); only pelvic dilatation (n = 59); pelvicaliceal dilatation (n = 33); pelvicaliceal and ureter dilatation (n = 18).

Results

Fetal pyelectasis of 7 mm was 89.3% sensitive and 78.9% specific <33 weeks, and ≥33 weeks pyelectasis of 10 mm was 88.4% and 78.6% in predicting subsequent postnatal pelvicaliectasis, respectively. Using a threshold of 4 mm <33 weeks and 7 mm ≥33 weeks yielded a sensitivity of 100% and a specificity of 18.7% and 47.8%, respectively. The median APD (range) at ≥33 weeks was 19 mm (9–36 mm) in patients requiring surgery and 13 mm (7–21 mm) in conservatively treated patients (p = 0.001). Thirteen of fourteen patients with APD ≥ 19 mm underwent surgery.

Conclusion

Women with ultrasonographically detected prenatal fetal pelvic dilatation of ≥4 mm before 33 weeks and of ≥7 mm from 33 weeks onwards of gestation should have repeated prenatal ultrasound scans and a detailed postnatal evaluation. The dilatations of an APD >4 mm before 33 weeks, which have disappeared at the post‐33‐week scan need no further investigation in the postnatal period. Copyright © 2004 John Wiley & Sons, Ltd.
Safety of fetal blood sampling by cordocentesis in fetuses with single umbilical arteries
Authors: Abdel‐Fattah Sherif A. , Bartha Jose L. , Kyle Phillipa M. , Denbow Mark L. , Soothill Peter W.
Published: August 2004

Objectives

To examine the safety of cordocentesis in fetuses with single umbilical arteries.

Methods

Retrospective analysis of all cases of cordocenteses in fetuses with single umbilical arteries over a five‐year period at one centre. We analysed the records for pregnancy details, outcomes, and procedure‐related complications, and compared these to similar data for cordocenteses procedures performed, during the same period, for similar indications in fetuses with three‐vessel cords.

Results

Twenty‐nine eligible cases were identified. All procedures were performed for the indication of fetal structural abnormalities, and seven fetuses (24%) had abnormal karyotypes. The median gestational age at the time of the procedure was 21 weeks (range 19–34 weeks). There were no procedure‐related fetal losses but the umbilical artery was inadvertently punctured in one case, resulting in prolonged bradycardia with spontaneous recovery. These outcomes compare favourably to those of a total of 134 cordocenteses procedures in fetuses with three‐vessel cords.

Conclusion

Cordocentesis in cases with single umbilical arteries does not appear to carry more risk than in cases with three‐vessel cord, and should continue to be performed by adequately trained specialists when indicated. Extra care should be undertaken to avoid puncturing the umbilical artery. Copyright © 2004 John Wiley & Sons, Ltd.
The relationship between maternal serum alpha‐fetoprotein and maternal haemoglobin
Authors: Bartha Jose L. , Omar Kiria M. , Soothill Peter W.
Published: August 2004

Objectives

To test the hypothesis that both second‐trimester maternal serum alpha‐fetoprotein (MSAFP) levels and Down syndrome–screening test are related to maternal haemoglobin concentration.

Methods

Three hundred and seventeen women in three groups according to their haemoglobin levels: normal haemoglobin concentration (between 10.5 and 13.2 g/dL) (n = 262; 82.6%), anaemia (less than 10.5 g/dL) (n = 11; 3.5%), or high haemoglobin levels (greater than 13.2 g/dL) (n = 44; 13.9%) were studied. MSAFP and Down syndrome risk (on the bases of maternal age, MSAFP and maternal serum β‐hCG concentrations) were recorded.

Results

MSAFP (MoM) was lower in women with high haemoglobin levels (0.79 MoM (0.66–1.14)) (p = 0.001) than in women with normal haemoglobin concentrations (1.00 MoM (0.81–1.26)). It was also decreased in women with anaemia (0.90 MoM (0.65–0.94)), even though the difference with women with normal haemoglobin levels was of borderline statistical significance (p = 0.06). The Down syndrome risk was higher in both anaemic women (1:850 (1:380–1:1400)) (p = 0.009) and women with high haemoglobin levels (1:1425 (1:460–1:3100)) (p = 0.036) than in women with normal haemoglobin concentration (1:1950 (1:800–1:5000)). A quadratic model was the best predictive model for both MSAFP (p = 0.02) and Down syndrome risk (p = 0.001) when considering maternal haemoglobin as the independent variable.

Conclusions

MSAFP is decreased and Down syndrome risk is increased in both anaemic and pregnant women with high haemoglobin concentration. Further studies are needed to establish whether adjustments for maternal haemoglobin are needed when giving Down syndrome risks based on biochemical markers. Copyright © 2004 John Wiley & Sons, Ltd.
Duplication of 9 p11.2‐p13.1: a benign cytogenetic variant
Authors: Di Giacomo Marilena C. , Cesarano Carla , Bukvic Nenad , Manisali Evangelia , Guanti Ginevra , Susca Francesco
Published: August 2004

The detection of very rare variants in prenatal diagnosis often causes counseling difficulties and anxiety in parents.

We describe a duplication of the proximal region of chromosome 9 short arm in two cases of prenatal diagnosis and in one young woman, with evidence that such rearrangement is an uncommon variant. The duplication was investigated using Fluorescence in situ hybridization (FISH). Although the cytogenetic findings were indicative of a ‘duplication 9p syndrome’ associated with mental and developmental retardation, we were able to demonstrate that the rearrangement was a heteromorphism with no phenotypic consequence. We also determined the breakpoint regions of the rearrangement and identified the BAC probes that precisely define the duplicated region devoid of risk of phenotypic effects. Copyright © 2004 John Wiley & Sons, Ltd.
Prenatal diagnosis of tetrasomy 9p with Dandy–Walker malformation
Authors: Hengstschläger Markus , Bettelheim Dieter , Drahonsky Regina , Repa Christa , Deutinger Josef , Bernaschek Gerhard
Published: August 2004

Objectives

To add to the knowledge of chromosomal abnormalities associated with Dandy–Walker malformation.

Methods

Molecular cytogenetic analyses of a chorionic villus sampling and of an amniocentesis of a fetus with Dandy–Walker malformation and abnormal somatic development.

Results

All cells examined showed a 47, XY, +idic(9p)(pter→q12::q12→pter) de novo karyotype. This report describes the fourth case of a tetrasomy 9p associated with Dandy–Walker malformation

Conclusions

This case, together with the three previously reported cases of an association with a tetrasomy 9p, indicate that this chromosomal aberration should be looked for when Dandy–Walker malformation is detected via prenatal ultrasonography. Copyright © 2004 John Wiley & Sons, Ltd.
Sonography in prenatal diagnosis of congenital adrenal hyperplasia
Authors: Saada Julien , Grebille Anne‐Gaëlle , Aubry Marie‐Cécile , Rafii Arash , Dumez Yves , Benachi Alexandra
Published: August 2004

Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder with an incidence of 1/15 000. More than 90% of CAH cases result from mutations of CYP21, leading to 21‐hydroxylase deficiency. In its classical form, CAH is severe and consists of the virilizing (increase of androgens) and salt‐wasting (lack of aldosterone) phenotype. When a proband exists, early prenatal diagnosis for CAH can be performed by direct molecular analysis in the first trimester. We describe herein two cases suggesting that the prenatal diagnosis of CAH can be initiated by the sonographic appearance of the adrenal gland at the second‐trimester scan in the absence of a family history. Copyright © 2004 John Wiley & Sons, Ltd.
First‐trimester prenatal screening for the common 35delG GJB2 mutation causing prelingual deafness
Authors: Coviello Domenico A. , Brambati Bruno , Tului Lucia , Percesepe Antonio , Sironi Francesca , Sahai Achal , Bertorelli Roberto , Forabosco Antonino
Published: August 2004

Objective

This study evaluates the prevalence of 35delG GJB2 mutation, the most common genetic mutation causing prelingual deafness, and its screening feasibility and acceptability in pregnant women undergoing first‐trimester CVS for chromosomal abnormality investigation.

Methods

Samples were taken from 5786 pregnant women who requested CVS for chromosomal analysis. The samples were split into two aliquots for chromosome and DNA analysis, respectively. The results of foetal karyotyping were provided 7 days after sampling, at which time the fully informed couple decided whether or not to undergo DNA testing.

Results

Of the 5449 eligible candidates, 2997 (55.0%) chose to undergo 35delG testing. Among them, 67 proved to be carriers of the mutation, resulting in a prevalence rate of 1:44.7 (2.23%). There were no homozygous foetuses, but two double heterozygous foetuses were found, and in one case the couple chose to terminate the pregnancy.

Conclusions

The results confirm the high frequency of 35delG mutation in the Italian population. The study shows that prenatal screening for GJB2 mutations in pregnant women with no retrospective risk for deafness appears to be feasible and highly acceptable. Consequently, given evidence that early evaluation and treatment significantly improve speech and language skills, as well as social and emotional well‐being in affected children, 35delG mutation analysis in pregnant women booking CVS primarily for chromosomal investigation could be considered a useful addition to more comprehensive population screening strategies. Copyright © 2004 John Wiley & Sons, Ltd.
A case of ring chromosome 22 with deletion of the 22q13.3 region associated with agenesis of the corpus callosum, fornix and septum pellucidum
Authors: Delcán José , Orera María , Linares Rafael , Saavedra Dolores , Palomar Angustias
Published: August 2004

We report a 16‐week‐gestation foetus obtained by voluntary abortion after prenatal diagnosis, in which a ring chromosome 22 was observed with deletion of the 22q13.3 region. A prenatal study of the amniotic fluid by standard chromosome technique with G bands and FISH (fluorescence in situ hybridisation) was performed. After the abortion, the anatomopathological study of the obtained foetus was carried out. Morphological and histological analysis of the foetus did not reveal severe physical abnormalities, although alterations of the nervous system were observed consisting of corpus callosum, fornix and septum pellucidum agenesia. It could be that the genes in this region that were involved in the development of the central nervous system were responsible for the alterations found in the morphological study. The wide range of manifestations observed in patients with this cytogenetic alteration is probably due to size differences in the deleted region. Copyright © 2004 John Wiley & Sons, Ltd.
Increased rate of aneuploid embryos in young women with previous aneuploid conceptions
Authors: Munné Santiago , Sandalinas Mireia , Magli Cristina , Gianaroli Luca , Cohen Jacques , Warburton Dorothy
Published: August 2004

Objectives

To determine whether a history of a previous aneuploid conception increases the rate of aneuploidy among women having preimplantation diagnosis (PGD).

Methods

Preimplantation embryos were tested for aneuploidy using FISH probes specific for chromosomes 13,15,16,17,18,21,22,X and Y.

Using logistic regression to control for maternal age, we compared the rates of aneuploidy and other chromosome errors in 344 embryos from women having PGD because of a history of a previous aneuploid conception, 363 embryos from 42 women having PGD because of X‐linked disorders and 1158 embryos from 135 women having PGD because of repeated in vitro fertilization failure.

Results

The frequency of aneuploidy differed significantly among patient groups for women younger than 35 (p = 0.003) but not for women older than 35. In women <35, the rate of detected aneuploidy was 37.4% in the Aneuploid group, 20.9% in the X‐linked group and 27.0% in the RIF group. (p = 0.0003 when the control groups are combined). The frequency of other chromosome abnormalities, as well as pregnancy and implantation rates, did not differ significantly among patient groups.

Conclusions

This study suggests that a history of a trisomic pregnancy, whether or not it was a viable trisomy, is associated with an increased risk of another aneuploid conception at conception. Copyright © 2004 John Wiley & Sons, Ltd.
Nonhomologous Robertsonian translocations (NHRTs) and uniparental disomy (UPD) risk: an Italian multicentric prenatal survey
Authors: Sensi A. , Cavani S. , Villa N. , Pomponi M. G. , Fogli A. , Gualandi F. , Grasso M. , Sala E. , Pietrobono R. , Baldinotti F. , Savin E. , Ferlini A. , Cecconi M. , Rossi S. , Gallone S. , Bellini C. , Neri G. , Martinoli E. , Simi P. , Dalprà L. , Genuardi M. , Dagna‐Bricarelli F. , Calzolari E.
Published: August 2004

Objectives

The risk of uniparental disomy (UPD) occurrence associated with the prenatal finding of balanced nonhomologous Robertsonian translocations (NHRTs) has been estimated only on limited empirical data. The aim of the study was to verify the estimate of the general risk, to get narrower confidence intervals by cumulating the data and to obtain risk estimates for specific translocation types.

Methods

We tested for UPD 160 prenatal specimens referred to the participant centers after the cytogenetic finding of NHRT.

Results

One case of upd(14)mat was found, associated with a 45,XX,der(14;22)mat fetal karyotype. The general empirical risk of UPD occurrence in NHRT carrier fetuses, corrected for the actual number of chromosomes analyzed, was 0.76% (95% CI 0.02–4.25%). Cumulative data with previous studies gives a general risk of UPD associated with NHRT of 0.80% (95% CI 0.17–2.34%). The UPD risk for the specific NHRT der(13;14) did not significantly differ from that of the other NHRTs taken together.

Conclusion

The present survey confirms the previously estimated risk of occurrence of UPD in offspring of NHRT carriers as a low, but not negligible risk, worth being investigated in prenatal diagnosis. Copyright © 2004 John Wiley & Sons, Ltd.
Investigation of lysosomal storage diseases in nonimmune hydrops fetalis
Authors: Burin Maira G. , Scholz Ana P. , Gus Rejane , Sanseverino Maria Teresa V. , Fritsh Alessandra , Magalhães José A. , Timm Fernanda , Barrios Patrícia , Chesky Marisa , Coelho Janice C. , Giugliani Roberto
Published: August 2004

Objective

To investigate lysosomal storage diseases (LSD) in cases of nonimmune hydrops fetalis (NIHF).

Methods

Thirty‐three cases of NIHF were investigated, 28 in the prenatal period and 5 in hydropic newborns. In addition to a general investigation for NIHF, specific enzymatic analyses for the detection of LSD were performed.

Results

In our sample, we detected five patients (15%) with LSD, each patient having one of the following diseases: mucolipidosis, Niemann–Pick disease, galactosialidosis, sialidosis and mucopolysaccharidosis type IV A.

Conclusion

Although LSDs are rare disorders as a group, they should be considered as a possible cause of NIHF, even in the absence of consanguinity or of a previous family history. By excluding the more frequent causes of NIHF, an LSD investigation assists in clarifying the etiology of many hydropic cases, making more appropriate genetic counseling for parents possible. Copyright © 2004 John Wiley & Sons, Ltd.
Evaluation of an integrated strategy for proteomic profiling of skeletal muscle
Authors: Le Bihan Marie‐Catherine , Tarelli Edward , Coulton Gary R.
Published: August 2004

Proteomic analysis of skeletal muscle presents particular challenges when trying to identify valid biomarkers of phenotypic change in small biopsies from genetically diverse human subjects. Currently, two‐dimensional (2‐D) gel electrophoresis and mass spectrometry are the chosen analytical strategies but 2‐D gels are not appropriate for analyzing proteins less than 11 kDa, they can suffer from problems of reproducibility and in routine use are not a viable high‐throughput technique. We have evaluated an integrated proteomic strategy employing Ciphergen ProteinChip® arrays, one‐dimensional polyacrylamide gel electrophoresis and mass spectrometry. Protein fingerprints characteristic of fast and slow contracting muscles from normal and kyphoscoliosis (ky) mutant mice were obtained from Ciphergen protein arrays. Eight statistically validated protein biomarkers have so far been identified capable of discriminating fast from slow muscle. Five of these showed further differential expression in ky versus normal BDL soleus muscles. Several biomarkers have been formally identified, and were myosin light chain isoforms shown previously to be expressed differentially by fast versus slow skeletal muscles. This integrated experimental approach using a model mouse muscle system shows the potential of Ciphergen protein array technology for proteomic analysis of small proteins in small muscle samples and its applicability for phenotypic characterization of skeletal muscle in general.
A critical evaluation of sample extraction techniques for enhanced proteomic analysis of recalcitrant plant tissues
Authors: Saravanan Ramu S. , Rose Jocelyn K. C.
Published: August 2004

Most published proteomics studies of bulk plant tissues use a procedure in which proteins are precipitated with trichloroacetic acid (TCA) and acetone (TCA‐A), but few attempts have been made to contrast this approach in a systematic way with alternative methods against a spectrum of tissues. To address this, TCA‐A was compared with another acetone‐based protocol (TCA‐B) or a phenol (Phe)‐based method, targeting a range of tomato tissues and three species of fruits that contain high levels of contaminating compounds: banana, avocado and orange. The Phe method gave a higher protein yield and typically greater resolution and spot intensity, particularly with extracts from tissues containing high levels of soluble polysaccharides. The methods also generated remarkably different two‐dimensional gel electrophoresis (2‐DE) protein spot patterns. Peptide mass fingerprinting was used to identify polypeptides that were common to multiple extracts or uniquely present in one extract type. While no clear pattern emerged to explain the basis for the differential protein extraction, it was noted that the Phe method showed enhanced extraction of glycoproteins. These results suggest that the Phe protocol is highly effective with more recalcitrant tissues and that a combination of TCA‐A and Phe methods provides enhanced 2‐DE based proteomic analyses of most plant tissues.
The synaptic vesicle proteome: A comparative study in membrane protein identification
Authors: Coughenour Holly D. , Spaulding Reggie S. , Thompson Charles M.
Published: August 2004

A proteomic analysis of the synaptic vesicle was undertaken to obtain a better understanding of vesicle regulation. Synaptic vesicles primarily consist of integral membrane proteins that are not well resolved on traditional isoelectric focusing/two‐dimensional gel electrophoresis (IEF/2‐DE) gels and are resistant to in‐gel digestion with trypsin thereby reducing the number of peptides available for mass spectrometric analysis. To address these limitations, two complementary 2‐DE methods were investigated in the proteome analysis: (a) IEF/sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (IEF/SDS‐PAGE) for resolution of soluble proteins and, (b) Benzyl hexadecyl ammonium chloride/SDS‐PAGE (16‐BAC/SDS‐PAGE) for resolution of integral membrane proteins. The IEF/SDS‐PAGE method provided superior resolution of soluble proteins, but could only resolve membrane proteins with a single transmembrane domain. The 16‐BAC/SDS‐PAGE method improved separation, resolution and identification of integral membrane proteins with up to 12 transmembrane domains. Trypsin digestion of the integral membrane proteins was poor and fewer peptides were identified from these proteins. Analysis of both the peptide mass fingerprint and the tandem mass spectra using electrospray ionization quadrupole‐time of flight mass spectrometry led to the positive identification of integral membrane proteins. Using both 2‐DE separation methods, a total of 36 proteins were identified including seven integral membrane proteins, 17 vesicle regulatory proteins and four proteins whose function in vesicles is not yet known.
Proteomic study of a model causative agent of harmful algal blooms, Prorocentrum triestinum II: The use of differentially expressed protein profiles under different growth phases and growth conditions for bloom prediction
Authors: Chan Leo Lai , Hodgkiss Ivor John , Wan Jennifer Man‐Fan , Lum John Hon‐Kei , Mak Abby Sin‐Chi , Sit Wai‐Hung , Lo Samuel Chun‐Lap
Published: August 2004

Simultaneous comparison of differentially expressed protein profiles of Prorocentrum triestinum grown under different growth phases and growth conditions indicated the presence of phase‐specific and stress‐responsive proteins, respectively. Correlation studies on these proteins in relation to cell division phasing patterns and to models of phytoplankton growth inferred the possible functions. Most notable among these proteins were groups of proteins thought to trigger or mediate cells through specific phases of division of this alga, e.g., BP1, BP2, PB1, PB2, and PB3. Other proteins (e.g., group 1 proteins) thought to be responsible for maintaining and supporting cell concentration under adverse conditions were found. Furthermore, another group of proteins (group 2 proteins) thought to be stress‐responsive were also detected. Taken overall, these differentially expressed proteins provided important information for uncovering various protective and adaptive mechanisms in the dinoflagellate's life cycle. These proteins have the potential to serve as “indicator proteins” for rapid assessment of the nutritional or metabolic status of these phytoplankton cells,and monitoring the differential expression of these phase‐specific proteins and stress‐specific proteins could be an important biomarker for bloom prediction.
Two‐dimensional electrophoresis database of Listeria monocytogenes EGDe proteome and proteomic analysis of mid‐log and stationary growth phase cells
Authors: Folio Patrice , Chavant Patrick , Chafsey Ingrid , Belkorchia Abdel , Chambon Christophe , Hébraud Michel
Published: August 2004

Listeria monocytogenes is the causative agent of listeriosis, one of the mo#st significant foodborne diseases in industrialized countries. The complete genome of the L. monocytogenes EGDe strain, belonging to the serogroup 1/2a, has been sequenced and is comprised of 2853 open reading frames. The objective of the current study was to construct a two‐dimensional (2‐D) database of the proteome of this strain. The soluble protein fractions of the microorganism were recovered either in the mid‐log or in the stationary phase of growth at 37°C. These fractions were analyzed by 2‐D electrophoresis (2‐DE), using immobilized pH gradient strips of various pH values (3–10, 3–6, and 5–8) for the first‐dimensional separations and 12.5% acrylamide gels for sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE). 201 protein spots corresponding to 126 different proteins were identified by matrix assisted laser desorption/ionization‐time of flight‐mass spectrometry (MALDI‐TOF‐MS). The 2‐DE maps presented here provide a first basis for further investigations of protein expression in L. monocytogenes. In this way, the comparison of proteome between cells in the exponential or stationary phase of growth at 37°C allowed us to characterize 161 variations in protein spot intensity, of which 38 were identified. Among the differentially expressed proteins were ribosomal proteins (RpsF, RplJ, and RpmE), proteins involved in cellular metabolism (GlpD, PdhD, Pgm, Lmo1372, Lmo2696, and Lmo2743) or in stress adaptation (GroES and ferritin), a fructose‐specific phosphotransferase enzyme IIB (Lmo0399) and different post‐translational modified forms of listeriolysin (LLO).
DARTs: A DNA‐based in vitro polypeptide display technology
Authors: Figueiredo Paul , Roberts Radclyffe L. , Nester Eugene W.
Published: August 2004

Display technologies link proteins with the genes that encode them, providing a means of selecting proteins with desired properties through the process of directed evolution. Here, we describe DNA/protein attachment and recovery tools (DARTs), a novel polypeptide display technology that utilizes the Agrobacterium tumefaciens protein VirD2 to generate DNA‐protein hybrid molecules. The resulting DNA‐protein hybrids are small, robust, and are not expected to be subject to the synthesis and selection biases associated with viral‐ and cell‐based display systems. We demonstrated that these DNA‐protein hybrids could be used to display a variety of peptides that bind to appropriate antibodies for immunodetection and immunopurification. Further, the DNA components of the hybrid molecules can hybridize to complementary DNA molecules in solution or on a solid substrate. Because full‐length VirD2 self‐associated, we constructed a truncation that did not self‐associate but still exhibited DNA linking activity and efficiently displayed peptides. Finally, we purified DNA‐protein hybrids using their displayed peptide epitopes and amplified their DNA components by polymerase chain reaction. We suggest that the DART polypeptide display system will be valuable for performing directed evolution and generating protein arrays.
Synthesis of chiral helical poly[p‐(oligopinanylsiloxanyl)phenylacetylene]s and enantioselective permeability of their membranes
Authors: Aoki Toshiki , Fukuda Tomoyuki , Shinohara Ken‐ichi , Kaneko Takashi , Teraguchi Masahiro , Yagi Masayuki
Published: August 2004

To develop better polymeric materials for optical‐resolution membranes, we synthesized nine chiral phenylacetylenes containing pinanyl groups. We used them to investigate the effects of chemical structures, including the number and position of the chiral groups in the monomers, on the induction of chirality in the main chain during polymerization and on the degree of enantioselectivity in the permeation of the polymeric membranes. The monomers included six new chiral p‐(oligomethylpinanylsiloxanyl)phenylacetylenes. The homopolymerizations of these nine monomers with a Rh complex produced high‐molecular‐weight polymers (molecular weight = 105–106). Of the five polymers with a chiral pinanyl group at the 1‐position of each oligosiloxanyl group, all except for two polymers showed high molar ellipticity in the main‐chain region in the circular dichroism spectra. This finding indicated that these polymers had a chiral helical main chain. The membranes fabricated from all the polymers synthesized in this study were high‐quality, except for two polymers. All these membranes showed enantioselective permeabilities for two amino acids and an alcohol. The membranes from the polymers with a chiral helical backbone, a high content of pinanyl groups, no oligodimethylsiloxane moieties, or a combination of these showed good enantioselectivities (= 1.7–640) in permeation. We propose that the sense of the main‐chain helicity determined the selectivity. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4502–4517, 2004
Complexation of phthalate oxygens in poly(ethylene phthalate) with silver ions and its effect on the formation of silver nanoparticles
Authors: Kang Sang Wook , Kim Jong Hak , Ko Dongkyun , Kim Chang Kon , Won Jongok , Char Kookheon , Kang Yong Soo
Published: August 2004

The interaction of a phthalate group in poly(ethylene phthalate) (PEP) with silver ion has been elaborated in detail to understand the reduction behavior of silver ions to silver nanoparticles. Previously, the polymer electrolytes consisting of silver ions dissolved in PEP have shown highly stable separation performance for propylene/propane mixtures primarily due to the retardation of the reduction reaction of silver ions to silver nanoparticles, which is possible by means of the chelating bonds between phthalate groups and silver ions. Thus, in this study, the interaction was systematically investigated by both the theoretical ab initio calculation and the experimental Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy. The results show that the interaction of silver ion with phthalate group in PEP is approximately two times stronger than that with other functional groups such as amide, ketone, and ester in various polymers, in which the latter ones show the rapid reduction reaction and consequently lose their olefin carrier activity with time. Therefore, it is concluded that the reduction reaction of silver ions to silver nanoparticles is retarded remarkably in PEP/silver salts systems primarily because of the strong interaction between the phthalate group in PEP and silver ion, and consequently the formation of silver nanoparticles would be effectively prohibited, as confirmed by transmission electron microscopy and ultraviolet–visible spectroscopy. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3344–3350, 2004
Elastic excitations in polycarbonate membranes
Authors: Tommaseo G. , Lescanne M. , Steffen W. , Fytas G. , Stamm M.
Published: August 2004

Brillouin light scattering was used to probe acoustic waves propagating with both longitudinal and transverse polarizations in the surface and the bulk of self‐supported particle track‐etched polycarbonate membranes with 15‐ and 80‐nm nanopores. The recorded scattering line shape at gigahertz frequencies reveals changes in the surface waves of the membranes which are more pronounced for the 80‐nm nanopores despite the low porosity (0.7 and 0.05%). Because the measured elastic constants (1.2 and 6.2 GPa) were found to compare very well with the values for thick polycarbonate film, modifications of the elasto‐optical coefficients and/or the transparency might be the reason for the different scattering line shapes. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3311–3317, 2004
Fracture behavior of triglyceride‐based adhesives
Authors: Lorenz Christian D. , Stevens Mark J. , Wool Richard P.
Published: August 2004

The use of natural plant oils in the production of adhesives has been the focus of much research because natural oils are a renewable resource which have environmental and economic advantages over the petroleum‐derived chemicals used in traditional adhesives. The network formation and the stress–strain behavior of these plant oil–based adhesives is studied using a combination of simulation techniques. An off‐lattice Monte Carlo simulation has been developed to model the formation of these networks via the free‐radical copolymerization of the triglycerides present in natural oils. Networks of systems representing the triglycerides found in soybean oil, linseed oil, and olive oil are generated, as are networks made from other “theoretical” natural oils. The structure of the networks is characterized by percolation analysis. The stress–strain behavior of these networks is studied using large‐scale molecular dynamics simulations. Tensile strains are applied to the networks and it is observed that with increasingnthe failure stress increases but the failure strain decreases. Also, for systems with low values ofn, large voids form while the system is strained and then the system fails cohesively. However, for largen, no significant voiding is observed and the system fails close to the interface. The simulation results are shown to be consistent with the vector percolation theoretical prediction for how the failure stress relates ton. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3333–3343, 2004
Type IIA on a compact Calabi‐Yau and D = 11 supergravity uplift of its orientifold
Authors: Misra A.
Published: August 2004

Using the prescription of [1] for defining period integrals in the Landau‐Ginsburg theory for compact Calabi‐Yau's, we obtain the Picard‐Fuchs equation and the Meijer basis of solutions for the compact Calabi‐Yau CY3(3,243) expressed as a degree‐24 Fermat hypersurface after resolution of the orbifold singularities. This is similar in spirit to the method of obtaining Meijer basis of solutions in [2] for the case wherein one is away from the orbifold singularities, and one is considering the large‐base limit of the Calabi‐Yau. The importance of the method lies in the ease with which one can consider the large and small complex structure limits, as well as the ability to get the “ln”‐terms in the periods without having to parametrically differentiate infinite series. We consider in detail the evaluation of the monodromy matrix in the large and small complex structure limits. We also consider the action of the freely acting antiholomorphic involution of [2,3] on D = 11 supergravity compactified on CY3(3,243) × S1 [4] and obtain the Kähler potential for the same in the limit of large volume of the Calabi‐Yau. As a by‐product, we also give a conjecture for the action of the orientation‐reversing antiholomorphic involution on the periods, given its action on the cohomology, using a canonical (co)homology basis. Finally, we also consider showing a null superpotential on the orientifold of type IIA on CY3(3,243), having taken care of the orbifold singularities, thereby completing the argument initiated in [2].
Abelian and non‐abelian D‐brane effective actions
Authors: Koerber P.
Published: August 2004

In this Ph.D. thesis, accepted at the Vrije Universiteit Brussel, we review and elaborate on a method to find the D‐brane effective action, based on BPS equations. Firstly, both for the Yang‐Mills action and the Born‐Infeld action it is shown that these configurations are indeed BPS, i.e. solutions to these equations saturate a Bogomolny bound and leave some supersymmetry unbroken. Next, we use the BPS equations as a tool to construct the D‐brane effective action and require that (a deformation of) these equations should still imply the equations of motion in more general cases. In the abelian case we managed to calculate all order in α′ four‐derivative corrections to the effective action and the BPS equations while in the non‐abelian case we obtained the effective action up to order α′4. Furthermore, we discuss a check based on the spectrum of strings stretching between intersecting branes. Finally, this Ph.D. thesis also discusses the construction of a boundary superspace which would be the first step to use the method of Weyl invariance in N = 2 superspace in order to again construct the D‐brane effective action. A more detailed summary of each section can be found in the introduction.
Remote homolog detection using local sequence–structure correlations
Authors: Hou Yuna , Hsu Wynne , Lee Mong Li , Bystroff Christopher
Published: August 2004

Remote homology detection refers to the detection of structural homology in proteins when there is little or no sequence similarity. In this article, we present a remote homolog detection method called SVM‐HMMSTR that overcomes the reliance on detectable sequence similarity by transforming the sequences into strings of hidden Markov states that represent local folding motif patterns. These state strings are transformed into fixed‐dimension feature vectors for input to a support vector machine. Two sets of features are defined: an order‐independent feature set that captures the amino acid and local structure composition; and an order‐dependent feature set that captures the sequential ordering of the local structures. Tests using the Structural Classification of Proteins (SCOP) 1.53 data set show that the SVM‐HMMSTR gives a significant improvement over several current methods. Proteins 2004. © 2004 Wiley‐Liss, Inc.
A robust method to detect structural and functional remote homologues
Authors: Shachar Ori , Linial Michal
Published: August 2004

With currently available sequence data, it is feasible to conduct extensive comparisons among large sets of protein sequences. It is still a much more challenging task to partition the protein space into structurally and functionally related families solely based on sequence comparisons. The ProtoNet system automatically generates a treelike classification of the whole protein space. It stands to reason that this classification reflects evolutionary relationships, both close and remote. In this article, we examine this hypothesis. We present a semiautomatic procedure that singles out certain inner nodes in the ProtoNet tree that should ideally correspond to structurally and functionally defined protein families. We compare the performance of this method against several expert systems. Some of the competing methods incorporate additional extraneous information on protein structure or on enzymatic activities. The ProtoNet‐based method performs at least as well as any of the methods with which it was compared. This article illustrates the ProtoNet‐based method on several evolutionarily diverse families. Using this new method, an evolutionary divergence scheme can be proposed for a large number of structural and functional related superfamilies. Proteins 2004. © 2004 Wiley‐Liss, Inc.
Analysis of protein homology by assessing the (dis)similarity in protein loop regions
Authors: Panchenko Anna R. , Madej Thomas
Published: August 2004

Two proteins are considered to have a similar fold if sufficiently many of their secondary structure elements are positioned similarly in space and are connected in the same order. Such a common structural scaffold may arise due to either divergent or convergent evolution. The intervening unaligned regions (“loops”) between the superimposable helices and strands can exhibit a wide range of similarity and may offer clues to the structural evolution of folds. One might argue that more closely related proteins differ less in their nonconserved loop regions than distantly related proteins and, at the same time, the degree of variability in the loop regions in structurally similar but unrelated proteins is higher than in homologs. Here we introduce a new measure for structural (dis)similarity in loop regions that is based on the concept of the Hausdorff metric. This measure is used to gauge protein relatedness and is tested on a benchmark of homologous and analogous protein structures. It has been shown that the new measure can distinguish homologous from analogous proteins with the same or higher accuracy than the conventional measures that are based on comparing proteins in structurally aligned regions. We argue that this result can be attributed to the higher sensitivity of the Hausdorff (dis)similarity measure in detecting particularly evident dissimilarities in structures and draw some conclusions about evolutionary relatedness of proteins in the most populated protein folds. Proteins 2004. © 2004 Wiley‐Liss, Inc.
Conformations of variably linked chimeric proteins evaluated by synchrotron X‐ray small‐angle scattering
Authors: Arai Ryoichi , Wriggers Willy , Nishikawa Yukihiro , Nagamune Teruyuki , Fujisawa Tetsuro
Published: August 2004

We constructed chimeric proteins that consist of two green fluorescent protein variants, EBFP and EGFP, connected by flexible linkers, (GGGGS)n (n = 3∼4), and helical linkers, (EAAAK)n (n = 2∼5). The conformations of the chimeric proteins with the various linkers were evaluated using small‐angle X‐ray scattering (SAXS). The SAXS experiments showed that introducing the short helical linkers (n = 2∼3) causes multimerization, while the longer linkers (n = 4∼5) solvate monomeric chimeric proteins. With the moderate‐length linkers (n = 4), the observed radius of gyration (Rg) and maximum dimension (Dmax) were 38.8 Å and 120 Å with the flexible linker, and 40.2 Å and 130 Å with the helical linker, respectively. The chimeric protein with the helical linker assumed a more elongated conformation as compared to that with the flexible linker. When the length of the helical linker increased (n = 5), Rg and Dmax increased to 43.2 Å and 140 Å, respectively. These results suggest that the longer helix effectively separates the two domains of the chimeric protein. Considering the connectivity of the backbone peptide of the protein, the helical linker seems to connect the two domains diagonally. Surprisingly, the chimeric proteins with the flexible linker exhibited an elongated conformation, rather than the most compact side‐by‐side conformation expected from the fluorescence resonance energy transfer (FRET) analysis. Furthermore, the SAXS analyses suggest that destabilization of the short helical linker causes multimerization of the chimeric proteins. Information about the global conformation of the chimeric protein is thus be necessary for optimization of the linker design. Proteins 2004. © 2004 Wiley‐Liss, Inc.
Activity of spinosad on stored‐tobacco insects and persistence on cured tobacco strips
Authors: Blanc Michel P , Panighini Cécile , Gadani Ferruccio , Rossi Luca
Published: August 2004

Every year raw tobacco and manufactured tobacco products are lost to two major storage pests, the cigarette beetle, Lasioderma serricorne (F) and the tobacco moth, Ephestia elutella (Hübner). Post‐harvest management of both insects is achieved through sanitation, insect monitoring and fumigation with phosphine. However, insect resistance to phosphine and control failures have been reported, and fumigants are under constant regulatory pressure. Here we report the evaluation of spinosad, a bioinsecticide derived from the fermentation of the soil micro‐organism Saccharopolyspora spinosa Mertz & Yao. Spinosad was first registered in 1997 and is now widely used as a field pest control agent on many crops, including tobacco. The insecticidal activity of the fermentation product (technical spinosad, TS) was measured by diet incorporation assays against L serricorne and E elutella larvae. Mortality levels were determined on newly hatched larvae and over the whole insect life cycle. For both species, no emergence of adult insects was observed in cured tobacco sprayed with 50 mg TS kg−1 and inoculated with eggs or newly hatched larvae. These results indicated that spinosad has potential for the control of both species in stored tobacco, since 100% control of both pests could be achieved at 50 mg TS kg−1, and with almost full control (90–95%) at 10 mg kg−1. We also monitored the stability of the product on cured tobacco. The original concentration of the main active component of TS, spinosyn A, did not change significantly over 18 months, indicating no loss of spinosad during a typical leaf storage period of time. Bioassays against larvae confirmed that the bioinsecticidal activity of spinosad was retained. Copyright © 2004 Society of Chemical Industry
Bermudagrass (Cynodon spp) dose–response relationships with clethodim, glufosinate and glyphosate
Authors: Webster Theodore M , Hanna Wayne W , Mullinix Benjamin G
Published: August 2004

Greenhouse studies were conducted to evaluate the sensitivity of three commercial cultivars, eight experimental cultivars and common bermudagrass to clethodim, glufosinate and glyphosate. Each herbicide was applied at eight doses. Data were regressed on herbicide dose using a log‐logistic curve (R2 = 0.56–0.95 for clethodim, R2 = 0.60–0.94 for glufosinate, and R2 = 0.70–0.96 for glyphosate). The herbicide rate that elicited a 50% plant response (I50) in the bermudagrass cultivars ranged from 0.04 to 0.19 kg ha−1 clethodim, 0.19 to 1.33 kg ha−1 glufosinate and 0.34 to 1.14 kg ha−1 glyphosate. Relative to other cultivars, common bermudagrass was intermediate in its response to clethodim and among the most tolerant cultivars to glufosinate and glyphosate. TifSport was relatively tolerant to clethodim and glufosinate compared with other cultivars, but relatively sensitive to glyphosate. One cultivar, 94‐437, was consistently among the most sensitive cultivars to each of the herbicides. While there were differential herbicide tolerances among the tested bermudagrass cultivars, there did not appear to be any naturally occurring herbicide resistance that could be commercially utilized. However, research indicated that breeding efforts should target herbicide resistance that is at least four times the registered use rate. Also, TifSport and Tifway have been identified as suitable representatives of triploid hybrid bermudagrass cultivars to be used to evaluate the success of turfgrass renovation programs. Copyright © 2004 Society of Chemical Industry
Activity of gut proteinases from Cry1Ab‐selected colonies of the European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae)
Authors: Siqueira Herbert A A , Nickerson Kenneth W , Moellenbeck Daniel , Siegfried Blair D
Published: August 2004

Susceptibility to the Cry1Ab protoxin and toxin from Bacillus thuringiensis (Berliner) and activity of gut proteinases were assessed in both susceptible and Cry1Ab‐selected colonies of European corn borer, Ostrinia nubilalis (Hübner). Resistance in two different selected colonies was at least 6‐ and 15‐fold for the Cry1Ab protoxin and 108‐ and 484‐fold for the Cry1Ab toxin. Activities of trypsin‐like, chymotrypsin‐like and elastase‐like proteinases were variable among the colonies tested and not indicative of a major contribution to Cry1Ab resistance. Activation of the 130‐kDa Cry1Ab protoxin occurred rapidly in all colonies, with no apparent differences among colonies. In addition, there were no apparent changes in activated Cry1Ab processing, indicating that proteolytic degradation was not associated with resistance. These results suggest that mechanisms other than proteolytic activation of protoxin and toxin degradation, such as target site modification may be involved in the resistance to B thuringiensis Cry1Ab in these O nubilalis colonies. Copyright © 2004 Society of Chemical Industry
State arbitrariness of the noninteracting fermion model in quantal density functional theory
Authors: Sahni Viraht , Slamet Marlina
Published: August 2004

In quantal density functional theory (Q‐DFT), any nondegenerate or degenerate ground or excited state of a system of electrons may be mapped to one of noninteracting fermions such that the equivalent density, energy, and ionization potential are obtained. As these model fermions are noninteracting, their effective potential energy, a local (multiplicative) operator, is the same for a particular state of the model system. The state of the noninteracting fermions, however, is arbitrary in that they could be in a ground or excited state. Hence, within Q‐DFT, there exist, in principle, an infinite number of local effective potential energy functions that can generate the same density as that of the interacting electrons. In this article, we demonstrate this state arbitrariness by mapping a (nondegenerate) ground state of the Hookean atom to two different noninteracting fermion systems: one in a singlet ground state (1s2) and the other in a singlet first excited state (1s2s). In each case, the density and energy determined are equivalent to that of the Hookean atom in the ground state, with the highest occupied eigenvalues of the model system being the negative of the ionization potential. The contrast with the mapping within traditional Kohn–Sham and generalized adiabatic connection Kohn–Sham density functional theories is also made. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004