bluuebunny/crossref_metadata_2025 huggingface dataset:
Recombinants of intrachromosomal transposition of subtelomeres in chromosomes 1 and 2: A cause of minute terminal chromosomal imbalances
Authors: Daniel Art , Baker Elizabeth , Chia Nicole , Haan Eric , Malafiej Paul , Hinton Lyn , Clarke Nigel , Adès Lesley , Darmanian Artur , Callen David
Published: January 2003

Two cases of submicroscopic recombinants of intrachromosomal transposition of telomeres, one each from chromosome 1 and 2 are described. Meiotic crossing‐over would generate the recombinants from these reciprocal rearrangements. In both cases, which were detected by FISH with subtelomeric probes, there is a minute deletion of the qter region and a second presence of the pter subtelomeric region on the respective qter, i.e., a duplication of 1pter or 2pter respectively. The deletion on 2qter (case 2) was confirmed by microsatellite inheritance and was of paternal origin, but in case 1 there was no detectable 1q deletion other than of the subtelomeric probe, and parental origin could not be determined. The present case 2 with del(2qter)/dup(2pter) shares many features with reported cases of simple deletion (2qter) but did not have features of Albright hereditary osteodystrophy, which are seen in half of such deletion patients. The clinical features present in case 1 were similar to those of the previously reported case of a submicroscopic 1qter deletion but also to cases with microscopically visible 1qter deletions, presumably because of gene enrichment in subtelomeric regions. Recombinants of such intrachromosomal subtelomere transpositions detected by subtelomeric probes may comprise up to 10% of submicroscopic pter or qter deletion cases. Other cases of this unusual mechanism may be detected with more common use of subtelomeric probes. It is suggested the bouquet associations of telomeres in early meiosis may facilitate such unusual rearrangements. © 2003 Wiley‐Liss, Inc.
Cryptic t(1;12)(q44;p13.3) translocation in a previously described syndrome with polymicrogyria, segregating as an apparently X‐linked trait
Authors: Zollino Marcella , Colosimo Cesare , Zuffardi Orsetta , Rossi Elena , Tosolini Alessandra , Walsh Christopher A. , Neri Giovanni
Published: January 2003

We report on the multistep progression to the correct genetic diagnosis in an apparently new syndrome of mental retardation and multiple congenital anomalies, including hypogenitalism and polymicrogyria. We had previously reported it as an X‐linked condition affecting four members (three males and one female) of a family [Zollino et al., 1992: Am J Med Genet 43:452–457]. Two of the four patients, both males, presented with a brain abnormality that was initially described as pachygyria, while the remaining two (one male and one female) did not. Our present study includes a clinical follow‐up on the patients, neuroradiological reexamination of one patient, X linkage studies and X inactivation analyses, and finally molecular cytogenetics, which allowed us to establish definitely the genetic causes of the condition. After the detection of a subtle t(1;12)(q44;p13.3) balanced translocation in healthy carriers, two unbalanced segregation products were observed in different patients, resulting in 1q44qter monosomy and 12p13.3pter trisomy in patients with polymicrogyria and severe psychomotor delay, 12p13.3pter monosomy and 1q44qter trisomy in the other two patients without polymicrogyria, with less severe mental retardation and less distinctive physical anomalies. Thus, this condition is no longer to be considered X‐linked, but the result of cryptic autosomal imbalance. Furthermore, this study identified an approximately 14 Mb interval in 1q44qter pathogenetically related to polymicrogyria. © 2003 Wiley‐Liss, Inc.
Bilateral microphthalmia with cyst, facial clefts, and limb anomalies: A new syndrome with features of Waardenburg syndrome, cerebro‐oculo‐nasal syndrome, and craniotelencephalic dysplasia
Authors: Gupta P.C. , Peralta D. , Parker M. , Crowe C. , Clark B. , Traboulsi E.I.
Published: January 2003

We report a patient with bilateral microphthalmia with cyst, limb anomalies, and multiple facial malformations. This patient has clinical features similar to Waardenburg ophthalmo‐acromelic syndrome, cerebro‐oculo‐nasal syndrome, and craniotelencephalic dysplasia. Although all of these syndromes are characterized by microphthalmia, the presently reported patient does not have the complete pattern of any of these syndromes, It is possible that he has a previously undescribed syndrome, most closely related to the cerebro‐oculo‐nasal syndrome with malformations outside the craniofacial region. More case reports are needed to further delineate this possibly new syndrome. © 2003 Wiley‐Liss, Inc.
Biological and environmental contributions to adaptive behavior in fragile X syndrome
Authors: Glaser Bronwyn , Hessl David , Dyer‐Friedman Jennifer , Johnston Cindy , Wisbeck Jacob , Taylor Annette , Reiss Allan
Published: January 2003

Fragile X syndrome is the most common cause of inherited developmental disability. The purpose of the present study is to understand how both biological and environmental influences affect the development of adaptive behavior in children with fragile X. In‐home assessments were conducted on 120 children (80 boys and 40 girls) with the fragile X full mutation and their unaffected siblings (58 boys and 62 girls). Hierarchical multiple regression analyses were utilized. Independent variables included biological or demographic variables specific to the child (age, gender, full‐scale IQ, and FMRP percentage), as well as factors specific to his/her environment (household income, home environment, maternal psychopathology, and effectiveness of educational/therapeutic services). Results of these analyses showed that for both boys with fragile X and the control sibling group, adaptive behavior was predicted by IQ, age, gender, and home environment. For girls with fragile X, adaptive behavior was most strongly associated with IQ. Adaptive behavior was not significantly associated with FMRP in boys or girls with fragile X. By examining the relative influences of biological and environmental factors on adaptive behavior in children with fragile X, we begin to lay the foundation for the development of more specific treatment studies in children with this disorder. © 2002 Wiley‐Liss, Inc.
Disclosing the mechanisms of origin of de novo short‐arm duplications of chromosome 9
Authors: Krepischi‐Santos Ana Cristina V. , Vianna‐Morgante Angela M.
Published: January 2003

Three de novo short‐arm duplications of chromosome 9 were investigated by fluorescence in situ hybridization (FISH) and genotyping of microsatellite loci with the aim of disclosing their mechanisms of origin. Two of these duplications were identified as direct and one as an inverted duplication, and they comprised nearly the entire 9p. In the two dirdup(9p), the distal breakpoints were mapped to subtelomeric sequences, whereas the proximal break boundaries were defined by pericentromeric sequences. The maternal origin of both duplications was demonstrated, and the presence of three different alleles in distal loci indicated that these rearrangements must have occurred prezygotically. In the invdup(9p), the proximal breakpoint was mapped at the alphoid sequences, which were partially duplicated on the tip of the rearranged 9p; subtelomeric and telomeric sequences were not detected, allowing the distal breakpoint to be mapped proximally to subtelomeric sequences. Genotyping of microsatellite loci allowed us to conclude that this invdup(9p) chromosome had a paternal origin. Homozygosity throughout the duplicated segment pointed to its probable postzygotic formation. Chromatid rearrangements appeared to have originated these 9p duplications, involving pericentromeric and subtelomeric sequences. These rearrangements might have been the result of recombination events between homologous repeats in these segments. © 2003 Wiley‐Liss, Inc.
De novo interstitial tandem duplication of chromosome 20p12.1p13
Authors: de Ravel T.J.L. , Vermeesch J.R. , Fryns J.‐P.
Published: January 2003

We report the first case of an individual with a de novo interstitial tandem duplication of the short arm of chromosome 20p12.1p13, discuss the clinical features, and propose the possible underlying mechanism of formation. © 2002 Wiley‐Liss, Inc.
Chromosomal fragility in patients with triple A syndrome
Authors: Reshmi‐Skarja Shalini , Huebner Angela , Handschug Katrin , Finegold David N. , Clark Adrian J.L. , Gollin Susanne M.
Published: January 2003

Triple A syndrome is a rare, autosomal recessive disorder characterized by alacrima, achalasia, and adrenal insufficiency. Previous studies have shown that the triple A gene (AAAS) maps to chromosomal band 12q13. Mutations in the AAAS gene have been identified in triple A syndrome patients; however, the function of this gene is still obscure. We used classical and high‐resolution chromosome analyses along with chromosome painting and DNA sequencing to study patients with triple A syndrome. We observed abnormalities in the heterochromatic region of chromosome 9 that included chromatid breaks, chromosome breaks, whole chromosome arm loss, and marker chromosomes, which occurred at unusually high frequencies in affected patients and heterozygotes. Our study raises the possibility of an association between chromosomal fragility in band 9q12 and triple A syndrome. Further investigation is necessary to understand the biologic basis of this finding in the context of triple A syndrome. © 2002 Wiley‐Liss, Inc.
Female carriers of fragile X premutations have no increased risk for additional diseases other than premature ovarian failure
Authors: Hundscheid R.D.L. , Smits A.P.T. , Thomas C.M.G. , Kiemeney L.A.L.M. , Braat D.D.M.
Published: January 2003

Carriers of fragile X premutations were previously considered phenotypically normal but are now known to be at risk for premature ovarian failure (POF). This prompted us to investigate whether premutation carriers (PC) have an increased risk for other diseases. We approached 306 women out of 84 fra(X) families of whom 264 (86.3%) participated in this study. A medical history was taken of these women. Whenever possible, the anamnestic data were verified with medical records. We first evaluated the occurrence of diseases that are commonly associated with menopause in PC and compared this to that in women with either a normal FMR‐1 gene or a full mutation. We found no statistically significant differences in the occurrence of diseases known to be associated with menopause, such as cardiovascular diseases and osteoporosis. However, lower bone mineral density was observed only in PC. Subsequently, we compared the occurrence of other medical problems between the two groups by estimating relative risks. PC did not demonstrate other diseases more commonly compared to non‐PC from the same families. These findings are important for the counseling of PC. Carriership of the premutation may affect the ovaries, but does not substantially increase the risk for additional medical problems. Once a PC does experience POF, she is at risk for early estrogen deprivation, which may lead to a premature decrease in bone density, when not treated. © 2002 Wiley‐Liss, Inc.
Extended phenotype of pontocerebellar hypoplasia with infantile spinal muscular atrophy
Authors: Rudnik‐Schöneborn Sabine , Sztriha László , Aithala Gururaj R. , Houge Gunnar , Lægreid Liv M. , Seeger Jürgen , Huppke Michael , Wirth Brunhilde , Zerres Klaus
Published: January 2003

Pontocerebellar hypoplasia (PCH) is rarely associated with anterior horn cell disease and designated as PCH‐1. This phenotype is characterized by severe muscle weakness and hypotonia starting prenatally or at birth with a life span not exceeding a few months in most cases. Milder disease courses with later onset and longer survival are normally not diagnosed as PCH‐1. We describe the clinical and neuroradiological findings in nine patients out of six siblingships with evidence of cerebellar defects and early onset spinal muscular atrophy (SMA), representing a broad spectrum of clinical variability. In all patients, the diagnosis of SMA (Werdnig‐Hoffmann disease) was made on the basis of electrophysiological data and muscle biopsy; however, genetic testing failed to confirm the diagnosis of infantile SMA with a gene defect on chromosome 5q and resulted in clinical reevaluation. Age at onset was after a normal period in the first months of life in three siblingships and pre‐ and postnatally in the other three families. Life span was 2–4 years in patients with later onset, and age at death occurred after birth or within months in the more severe group. Two siblingships showed discordant ages at death despite similar treatment. In contrast to the previous definition of PCH‐1, our observations suggest the existence of milder phenotypes with pontocerebellar hypoplasia or olivopontocerebellar atrophy in combination with anterior horn cell loss. A pontine involvement is not necessarily seen by neuroimaging methods. The genetic basis of PCH‐1 remains to be determined. The gene locus for infantile SMA on chromosome 5q could be excluded by linkage studies. Parental consanguinity and affected siblings make autosomal recessive inheritance most likely. © 2002 Wiley‐Liss, Inc.
Autopsy on a case of Roberts syndrome reported in 1672: The earliest description?
Authors: Bates A.W.
Published: January 2003

In 1672, François Bouchard reported the autopsy of a male infant discovered on public exhibition at Leiden. The findings of tetraphocomelia more severe in the upper limbs with reduction in the number and length of digits, hydrocephalus, bilateral cleft lip, micrognathia, and cryptorchidism are consistent with a diagnosis of Roberts syndrome. Bouchard did not find internal abnormalities other than hydrocephalus, which he attempted to demonstrate by showing decreased specific gravity of the brain. Death was due to umbilical vein hemorrhage following birth trauma. © 2002 Wiley‐Liss, Inc.
DiGeorge/velocardiofacial syndrome: FISH studies of chromosomes 22q11 and 10p14, and clinical reports on the proximal 22q11 deletion
Authors: Bartsch Oliver , Nemecková Michaela , Kocárek Eduard , Wagner Annett , Puchmajerová Alena , Poppe Maja , Ounap Katrin , Goetz Petr
Published: January 2003

DiGeorge anomaly/velocardiofacial syndrome (DG/VCFS) occurs with different deletion intervals on chromosomes 22q11, while the DiGeorge anomaly (with other findings) is seen in patients with deletions of 10p14. The clinical outcome with the common 22q11 deletion (90% of cases) is well known, but the outcome with the less frequent deletion types has not been well documented. Using cytogenetic and fluorescence in situ hybridization (FISH) analysis we studied a series of 295 patients with suspected DG/VCFS. We identified 58 subjects with a 22q11 deletion, and none with a 10p deletion. Fifty‐two subjects had the common deletion, five had the proximal deletion, and one had an atypical proximal deletion due to a 1;22 translocation. We report clinical data of four subjects with the proximal 22q11 microdeletion, and of one patient with the atypical proximal deletion. The anomalies observed with the proximal 22q11 microdeletion fell within the DG/VCFS spectrum. Two females, 6 and 25 years old, had normal mental development. Normal development has been reported with the common 22q11 deletion, but only in a minority of cases. This study may indicate a better intellectual and/or behavioral outcome with the proximal vs. the common 22q11 deletion, rather than a chance finding. © 2002 Wiley‐Liss, Inc.
Exclusion of RNX as a major gene in congenital central hypoventilation syndrome (CCHS, Ondine's curse)
Authors: Amiel Jeanne , Pelet Anna , Trang Ha , de Pontual Loïc , Simonneau Michel , Munnich Arnold , Gaultier Claude , Lyonnet Stanislas
Published: January 2003

Congenital central hypoventilation syndrome (CCHS) is a rare condition for which segregation analyses have suggested genetic factors. The respiratory phenotype of Rnx knock‐out mice together with the Rnx expression at the brainstem level prompted us to consider the RNX gene as a candidate for CCHS in human. The screening of the RNX gene in a series of 25 patients with CCHS did not reveal any significant nucleotide variation. We therefore conclude that RNX is not a major gene for CCHS in human. © 2002 Wiley‐Liss, Inc.
Crystallographic report: Bis(pyrrolinedithiocarbamato)mercury(II)
Authors: Lai Chian Sing , Tiekink Edward R. T.
Published: January 2003

The mononuclear structure of Hg(S2CN(CH2)4)2 has crystallographically imposed twofold symmetry and features chelating dithiocarbamate ligands that form asymmetric HgS bond distances leading to a heavily distorted tetrahedral geometry. Copyright © 2003 John Wiley & Sons, Ltd.
Crystallographic report: Chloro(N,N‐diethyldithiocarbamato)(4,7‐dimethyl‐1, 10‐phenanthroline)mercury(II) hemi‐chloroform solvate
Authors: Lai Chian Sing , Tiekink Edward R. T.
Published: January 2003

The X‐ray crystal structure of Hg(S2CNEt2)(4,7‐Me2‐phen)Cl features an essentially four‐coordinate geometry for mercury within a ClN2S donor set that defines a distorted tetrahedral arrangement. Copyright © 2003 John Wiley & Sons, Ltd.
Organotin antifouling paints and their alternatives
Authors: Omae Iwao
Published: January 2003

Tributyltin and triphenyltin compounds have excellent biocidal properties and almost all vessels in the world have used these paints since early in the 1960s. Contrary to expectation, as shown by experimental data at the beginning of organotin chemistry, triorganotins are exceptionally stable in the sediment or in dark places in the deep sea. Since triorganotins do not decompose rapidly in seawater, many incidences of deformities in some shellfish have been linked to their presence, even when present at extremely low concentrations.

Alternative tin‐free antifoulants containing other biocides, such as copper compounds and organic compounds, have been developed and used since the late 1980s. Some nations have already banned the use of organotin antifouling compounds for small vessels, and in 2001 the International Maritime Organization decided to ban completely the use of the organotin compounds from the year 2003. Therefore, it is necessary to find economically and environmentally better biocidal substances as soon as possible. Moreover, the development of antifoulants containing environmentally safe natural products, fouling release coatings, electroconductive coatings, etc. have long been anticipated from the new point of conservation of the world marine environment. Copyright © 2003 John Wiley & Sons, Ltd.
Laser photolysis of trimethoxysilane: chemical vapour deposition of nanostructured silicone powders with SiH and SiOCH3 bonds
Authors: Tomovská Radmila , Bastl Zdenĕk , Bohác̆ek Jaroslav , Pola Josef
Published: January 2003

Gas‐phase photolysis of trimethoxysilane, achieved for the first time by focused ArF laser radiation at 193 nm, yields C1,2 hydrocarbons, methanol and carbon monoxide along with ultrafine nanostructured silicone powder possessing SiO3 and SiO4 configurations and SiH and SiOCH3 bonds. The photolytic process, resulting in efficient removal of the methyl groups, is explained as a multitude of steps involving cleavages of all the available bonds. Copyright © 2003 John Wiley & Sons, Ltd.
Radioprotective activity of metalladithioacetals derived from N‐substituted naphthylethylimidazoline
Authors: Célariès Benoît , Amourette Christine , Lion Claude , Rima Ghassoub
Published: January 2003

A number of organosilicon and organogermanium derivatives of N‐substituted 2‐[1‐(1‐naphthyl)ethyl]‐2‐imidazoline have been reported and the toxicity of these compounds has been determined in mice. In this paper we report the evaluation of the radioprotective activity of new sila‐ and germa‐dithioacetals derived from N‐substituted 2‐[1‐(1‐naphthyl)ethyl]‐2‐imidazoline. Copyright © 2003 John Wiley & Sons, Ltd.
Preparation of Si–C–N–Fe magnetic ceramics from iron‐containing polysilazane
Authors: Li Yongming , Zheng Zhimin , Reng Changyu , Zhang Zhijie , Gao Wei , Yang Shiyan , Xie Zemin
Published: January 2003

A new type of hyperbranched polysilazane containing iron (PSZI) compound was synthesized by the polycondensation of silazane lithium salts with FeCl3, and the structure of the PSZIs was investigated by IR, NMR and elemental analyses. The PSZIs were pyrolyzed under nitrogen, argon or NH3, and magnetic ceramics could be obtained. The ceramic yields of the PSZIs were higher than those of their corresponding silazanes, and the PSZIs or silazanes with reactive groups containing SiH, CHCH2 or higher branched structures had higher yields. The magnetism of the ceramics could be controlled by a pyrolytic atmosphere and temperature: the saturation magnetization Ms ranged from 20 to 100 emu g−1 and coercivity Hc ranged from 463 to 50 Oe. The transformation of the magnetic loop of the PSZIs pyrolyzed at different temperatures under NH3 was quite different from those under nitrogen. It was shown by X‐ray diffraction measurements that the magnetic crystalline form could exist as Fe4N, Fe(0) or Fe3N depending on temperature under NH3, but under a nitrogen atmosphere Fe(0) was nearly the only magnetic crystalline form from 600 to 1100 °C. By dipping or spin‐coating of the PSZI solution, then through pyrolysis under nitrogen, argon or NH3, thin uniform magnetic ceramic films could be fabricated on the substrates. Copyright © 2003 John Wiley & Sons, Ltd.
Kinetics and mechanism of the reaction of allyl chloride with trichlorosilane catalyzed by carbon‐supported platinum
Authors: Marciniec Bogdan , Maciejewski Hieronim , Duczmal Wojciech , Fiedorow Ryszard , Kityński Dariusz
Published: January 2003

The kinetics of substrate conversions in the commercially important hydrosilylation of allyl chloride with trichlorosilane, catalyzed by active carbon‐supported platinum, as well as the yields of the main product (3‐chloropropyltrichlorosilane) and by‐products (tetrachlorosilane, propyltrichlorosilane) have been studied. On the basis of the measurements performed, the pseudo first‐order rate constants (kobs, k1 and k2 from the model of competitive reactions) and activation energy (Ea = 11 kcal mol−1 (46.2 kJ mol−1)) were determined. The data obtained point to a non‐linear dependence of kobs on the catalyst amount. From the kinetic relationships, the kinetic equation was deduced. All the results of kinetic, IR spectroscopic and thermogravimetric measurements, as well as the derived kinetic equation, have confirmed the general model of consecutive–competitive reaction involving the formation of a surface complex C1 which can decompose in two directions according to the Chalk–Harrod mechanism. Copyright © 2003 John Wiley & Sons, Ltd.
Effects of tributyltin(IV) chloride on the gametes and fertilization of Ascidia malaca (Ascidiacea: Tunicata)
Authors: Villa L. , Agati P. D' , Mansueto C. , Pellerito C. , Scopelliti M. , Fiore T. , Nagy L. , Pellerito L.
Published: January 2003

Ascidia malaca gametes before fertilization incubated in 10−5 or 10−7 M solutions of tributyltin(IV) chloride, TBTCl, for 3 h appear highly damaged under transmission electron microscopy observation. Also, the fertilization process is affected by the compound: the damaged spermatozoa are present in the vitelline coat and the egg does not cleave. An increase of microbodies, structurally similar to peroxisomes, have been detected in the egg peripheral cytoplasm, probably in relation to their role in alleviating damage to some cellular components. The results have shown that the reproduction of ascidians under unfavourable environmental conditions is prevented. Copyright © 2003 John Wiley & Sons, Ltd.
Mechanical and barrier properties of edible starch–protein‐based films
Authors: Jagannath J. H. , Nanjappa C. , Das Gupta D. K. , Bawa A. S.
Published: January 2003

The present investigation dealt with the mechanical properties, water‐vapor transmission behavior at different relative humidity conditions, and DSC thermograms of edible films formulated using various proteins (casein, gelatin, albumin) in combination with starch and nonthermal as well as intense thermal blending. Nonthermal blended film showed in the DSC thermogram a double Tg, indicating poor miscibility of the components and, hence, a poor film‐forming property. However, the DSC thermogram of all the films based on intense thermal blending showed a single Tg, indicating the complete molecular miscibility of the components. Casein‐based film showed a lower water‐vapor transmission rate, water gain at different relative humidity conditions, and higher tensile strength compared to its counterparts containing gelatin and albumin. Since the casein–starch blend gave better film properties, a blend of hydrophobic carnauba wax and casein was prepared to compare the properties of hydrophilic–hydrophilic and hydrophobic–hydrophilic blends. Both these blends compared well with respect to the water‐vapor transmission rate. Wax‐based film showed multiphased behavior in the DSC thermograms and the percent elongation was lower as compared to the casein–starch blend. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 64–71, 2003
Unique expression patterns of the retinoblastoma (Rb) gene in intact and lens regeneration‐undergoing newt eyes
Authors: Thitoff Angela R. , Call Mindy K. , Del Rio‐Tsonis Katia , Tsonis Panagiotis A.
Published: January 2003

Based on the role of retinoblastoma (Rb) in lens development and in the cell cycle reentry of muscle cells during limb regeneration, we have analyzed expression or Rb patterns in intact and lens regeneration‐undergoing newt eyes. We find that in intact newt eye Rb is expressed in the retina as a gradient with higher levels in the photoreceptor layer and virtually no expression in the ganglion layer. In addition, a second gradient was detected within the photoreceptor layer with expression diminishing at the dorsal and ventral regions. In the intact lens, Rb is expressed in the lens epithelium and in the differentiating lens fibers at the bow region. During lens regeneration, Rb is expressed very strongly in the differentiating lens fibers, but not in the lens epithelium. Using an antibody specific to the hyperphosphorylated form of Rb, we detected the inactive protein only in the pigment epithelial cells of the iris. These distinct patterns might be related to the regenerative potential of the lens in the newt. Anat Rec Part A 271A:185–188, 2003. © 2003 Wiley‐Liss, Inc.
Slug expression during organogenesis in mice
Authors: Oram Kathleen F. , Carver Ethan A. , Gridley Thomas
Published: January 2003

The vertebrate Slug gene encodes a zinc finger‐containing transcriptional repressor. Here we report expression of the mouse Slug gene during organogenesis and late fetal development using histochemical detection of β‐galactosidase expressed from a targeted SluglacZ knock‐in allele. The Slug gene is highly expressed in the mesenchymal or stromal component of numerous organs. It is also highly expressed in craniofacial mesenchyme, in bone of both mesodermal and neural crest origin, and in the outflow tract and the endocardial cushions of the heart. Anat Rec Part A 271A:189–191, 2003. © 2003 Wiley‐Liss, Inc.
Electron microscopy of functional ribosome complexes
Authors: Frank Joachim
Published: January 2003

Cryoelectron microscopy has made a number of significant contributions to our understanding of the translation process. The method of single‐particle reconstruction is particularly well suited for the study of the dynamics of ribosome–ligand interactions. This review follows the events of the functional cycle and discusses the findings in the context provided by the recently published x‐ray structures. © 2003 Wiley Periodicals, Inc. Biopolymers 68: 223–233, 2003
Assembly of the 30S ribosomal subunit
Authors: Culver Gloria M.
Published: January 2003

Ribosomes are large macromolecular complexes responsible for cellular protein synthesis. The smallest known cytoplasmic ribosome is found in prokaryotic cells; these ribosomes are about 2.5 MDa and contain more than 4000 nucleotides of RNA and greater than 50 proteins. These components are distributed into two asymmetric subunits. Recent advances in structural studies of ribosomes and ribosomal subunits have revealed intimate details of the interactions within fully assembled particles. In contrast, many details of how these massive ribonucleoprotein complexes assemble remain elusive. The goal of this review is to discuss some crucial aspects of 30S ribosomal subunit assembly. © 2003 Wiley Periodicals, Inc. Biopolymers 68: 234–249, 2003
Stepwise induced fit in the pico‐ to nanosecond time scale governs the complexation of the even‐skipped transcriptional repressor homeodomain to DNA
Authors: Flader Wolfgang , Wellenzohn Bernd , Winger Rudolf H. , Hallbrucker Andreas , Mayer Erwin , Liedl Klaus R.
Published: January 2003

Induced fit effects in the complex of a DNA decamer with two even‐skipped transcriptional repressor homeodomain molecules were investigated by means of molecular dynamics simulations. Dynamics of these effects are found to be in the time scale from pico‐ to nanoseconds. First steps are made by the fast‐moving DNA backbone phosphates, which upon binding change their BI/BII substate distribution. Further rearrangements in the DNA double helix induced upon complexation, like bending of the helix axis, changes of the minor groove width, and of different helical parameters, are slower and occur within a few nanoseconds. The flexibility of the DNA, especially of its backbone, seems thereby to play an important role for specific DNA ligand recognition. © 2002 Wiley Periodicals, Inc. Biopolymers 68: 139–149, 2003
Operator recognition by the phage 434 cI repressor: MD simulations of free and bound 50‐bp DNA reveal important differences between the OR1 and OR2 sites
Authors: Hartmann Brigitte , Sullivan Michael R. , Harris Lester F.
Published: January 2003

Using molecular dynamics simulations in explicit solvent, we investigated the behavior of a 50‐bp DNA sequence containing the 434 bacteriophage operators OR1 and OR2 separated by an 8‐bp spacer. Two simulations of 1 ns each were carried out, with DNA alone and with DNA complexed to dimers of the R1–69 DNA binding domain of the phage 434 cI repressor protein at the OR1 and OR2 sites. Strong correlations among average structural parameters are observed between our simulations and available experimental data for the bound OR1/OR2 subsites. In the free state, some differences appear between the three relevant fragments (OR1, the spacer, and OR2). Unbound OR1 exhibits a large, shallow major groove into which the base atoms protrude and is also bent toward the major groove. This structure is maintained because structural fluctuations are weak. Unbound OR2 resembles canonical B‐DNA although the structural parameters show greater fluctuations, essentially due to a malleable step (the innermost CpA/TpG), absent in OR1. Complexation with the proteins slightly alters the base positions but strongly modifies the sugar and backbone motions. The most crucial repressor effects are changes in the flexibility of the OR1/OR2 sites. Structural fluctuations are enhanced for OR1, conferring a favorable energetic contribution to the OR1 binding, whereas they are reduced for OR2. Therefore, both structural and dynamic properties of DNA suggest OR1 is the most attractive site for the repressor, which may explain the different binding association constants observed for the OR1 and OR2 sites. Finally, we also investigated the impact of the protein on the DNA backbone dynamics and find that direct or indirect interactions facilitate the DNA structural variations required for achieving complementarity with the protein. © 2003 Wiley Periodicals, Inc. Biopolymers 68: 250–264, 2003
Surface electrostatic effects in oligonucleotide microarrays: Control and optimization of binding thermodynamics
Authors: Vainrub Arnold , Montgomery Pettitt B.
Published: January 2003

We present a theoretical thermodynamic framework for the design of more efficient oligonucleotide microarrays. A general thermodynamic relation is derived to describe the electrostatic surface effects on the binding of the assayed biomolecule to a surface‐tethered molecular probe. The relation is applied to analyze how the nucleic acid target, the oligonuleotide probe, and their DNA duplex electrostatic interactions with the surface affect the hybridization on DNA arrays. Taking advantage of a closed form exact solution of the linear Poisson–Boltzmann equation for a charged ion‐penetrable sphere in electrolyte solution interacting with a plane wall, we study the effects of the surface and solution conditions. Binding free energy is found as a function of the surface material, dielectric or metal, the surface charge density, linker molecule length, temperature, and added salt content. The charge or electric potential of the dielectric or metal surface, respectively, is shown to dominate the hybridization, especially at low added salt or short linker length. We predict that substantial enhancement of sensitivity, selectivity, and reliability of microarrays can be achieved by control of the surface conditions. As examples, we discuss how to overcome two limitations of current technologies: nonequal sensitivity of the probes with different GC and AT bases content, and poor match/mismatch discrimination. In addition, we suggest the design of microarray conditions where the tested nucleic acid is unfolded, thus making possible the screening of a larger sequence with single nucleotide resolution. These promising findings are discussed and further experimental tests suggested. © 2003 Wiley Periodicals, Inc. Biopolymers 68: 265–270, 2003
Molecular mass and chain conformation of carboxymethylated derivatives of β‐glucan from sclerotia of Pleurotus tuber‐regium
Authors: Zhang Mei , Zhang Lina , Chi Keung Cheung Peter
Published: January 2003

Seven water‐insoluble (1 → 3)‐β ‐D‐glucan fractions TM8‐1 to TM8‐7 with weight‐average molecular mass Mw ranged from 2.22 to 77.4 × 104 obtained from the sclerotia of Pleurotus tuber‐regium were carboxymethylated to produce the water‐soluble fractions CTM8‐1 to CTM8‐7 with Mw ranged from 3.87 to 87.8 × 104. The degree of substitution (DS) of CTM8 fractions was analyzed by ir and elemental analysis (EA) to be 0.3–0.68. The Mw and the intrinsic viscosity [η] of the CTM8 fractions were measured by size‐exclusion chromatography combined with multiangle laser light scattering (SEC‐MALLS), MALLS, and viscometry in phosphate buffer solution (PBS) at 37°C. The dependencies of [η] and radius of gyration 〈s2〉z1/2 on Mw for the CTM8 samples were found to be [η] = (8.82 ± 0.03) × 10−3 Mw0.78 ± 0.04 (cm3 g−1) and 〈s2〉z1/2 = (3.09 ± 0.05) × 10−3 Mw0.75 ± 0.06 (nm) in the Mw range from 3.87 × 104 to 53.2 × 104. Based on current theories for wormlike chain model, the conformational parameters of the CTM8 were obtained to be 790 (nm−1) for ML, 9.6 (nm) for q, which were higher than those of the native TM8 fractions, suggesting a more extended flexible chain of CTM8 in PBS. On the whole, the CTM8 fractions showed higher antitumor activity than their corresponding TM8 fractions. In view of data from molecular parameters and bioactivity, the antitumor activity of the CTM8 fractions may be correlated to its water solubility and relatively extended chain. © 2002 Wiley Periodicals, Inc. Biopolymers 68: 150–159, 2003
Simulation of the bis‐(penicillamine) enkephalin in ammonium chloride solution: A comparison with sodium chloride
Authors: Marlow Gail E. , Pettitt B. Montgomery
Published: January 2003

In order to quantify specific ion effects, a simulation study of bis(penicllamine) enkephalin, also known as DPDPE, has been performed in aqueous ammonium chloride solution and has been compared to a previous simulation of DPDPE in aqueous sodium chloride solution. Global thermodynamics have been calculated for a model system and the solution environment around DPDPE has been characterized. Associations of ions with DPDPE have been investigated. The observed differences between sodium chloride solution and ammonium chloride solution suggest that individual cations affect the solvation and peptide binding properties of a given anion. © 2003 Wiley Periodicals, Inc. Biopolymers 68: 192–209, 2003
Folding of peptides characterized by c3Val, a highly constrained analogue of valine
Authors: Peggion Cristina , Formaggio Fernando , Crisma Marco , Toniolo Claudio , Jiménez Ana I. , Cativiela Carlos , Kaptein Bernard , Broxterman Quirinus B. , Saviano Michele , Benedetti Ettore
Published: January 2003

Using a combined chemical/chiral chromatographic approach we synthesized an N‐protected derivative of (R)–c3Val, a severely conformationally restricted Cα‐tetrasubstituted α‐amino acid characterized by a Cβ,β‐dimethylated cyclopropane system. A set of terminally protected derivatives and model peptides (to the heptamer level), containing one or two (R)–c3Val residues in combination with either Aib or Gly residues, was prepared by solution methods. A detailed solution and crystal‐state conformational investigation, based on Fourier transform infrared (FTIR) absorption, 1H‐NMR, and x‐ray diffraction techniques, performed in comparison with a similar study on related derivatives and peptides rich in (αMe)Val, the prototype of Cα‐tetrasubstituted α‐amino acids of this subfamily, allowed us to conclude the following: (a) c3Val is a good β‐bend and helix former, although less efficient than (αMe)Val. (b) The relationship between α‐carbon chirality and screw sense of the folded structure formed is the same as that of (αMe)Val, i.e., the (R)‐enantiomer has a strong left‐handed bias. (c) c3Val seems more prone than (αMe)Val to fold into a γ‐bend conformation. The conformational propensities of Cβ,β‐disubstituted Ac3c residues are also discussed in comparison with those of the parent cyclopropane residue. © 2002 Wiley Periodicals, Inc. Biopolymers 68: 178–191, 2003
The thermodynamic contribution of the 5‐methyl group of thymine in the two‐ and three‐stranded complexes formed by poly(dU) and poly(dT) with poly(dA)
Authors: Ross Philip D. , Howard Frank B.
Published: January 2003

To assess the thermodynamic contribution of the 5‐methyl group of thymine, we have studied the two‐stranded helical complexes poly(dA) · poly(dU) and poly(dA) · poly(dT) and the three‐stranded complexes—poly(dA) · 2poly(dU), poly(dA) · poly(dT) · poly(dU) and poly(dA) · 2poly(dT)—by differential scanning calorimetry, and uv optical melting experiments. The thermodynamic quantities associated with the 3 → 2, 2 → 1, and 3 → 1 melting transitions are found to vary with salt concentration and temperature in a more complex manner than commonly believed. The transition temperatures, Tm, are generally not linear in the logarithm of concentration or activity of NaCl. The change in enthalpy and in entropy upon melting varies with salt concentration and temperature, and a change in heat capacity accompanies each transition. The poly(dA) · 2poly(dU) triple helix is markedly different from poly(dA) · 2poly(dT) in both its CD spectrum and thermodynamic behavior, while the poly(dA) · poly(dT) · poly(dU) triple helix resembles poly(dA) · 2poly(dT) in these properties. In comparing poly(dA) · 2poly(dT) with either the poly(dA) · poly(dT) · poly(dU) or the poly(dA) · 2poly(dU) triplexes, the substitution of thymine for uracil in the third strand results in an enhancement of stability against the 3 → 2 dissociation of ΔΔG° = −135 ± 85 cal (mol A)−1 at 37°C. This represents a doubling of the absolute stability toward dissociation compared to the triplexes with poly(dU) as the third strand. The poly (dA) · poly (dT) duplex is more stable than poly(dA) · poly(dU) by ΔΔG° = −350 ± 60 cal (mol base pair)−1 at 37°C. Poly(dA) · poly(dT) has 50% greater stability than poly(dA) · poly(dU) as a result of the dT for dU substitution in the duplex. © 2003 Wiley Periodicals, Inc. Biopolymers 68: 210– 222, 2003
Initial multicenter experience with a novel distal protection filter during carotid artery stent implantation
Authors: Grube Eberhard , Colombo Antonio , Hauptmann Eugen , Londero Hugo , Reifart Nicolaus , Gerckens Ulrich , Stone Gregg W.
Published: January 2003

Atheroembolization resulting in transient or permanent neurologic impairment is the most common complication of catheter‐based percutaneous carotid artery intervention. Protection of the distal cerebral vasculature during carotid stent implantation may enhance procedural safety. Carotid stent implantation with distal cerebral protection using the FilterWire EX was performed in 35 consecutive patients undergoing 36 procedures at six centers. The FilterWire was delivered and deployed successfully in all 36 cases, and embolic material was retrieved from 74% of procedures. The 30‐day rate of major adverse events (death, major or minor stroke) was 0%. Transient ipsilateral periprocedural neurologic ischemia developed in two patients (5.7%), both resolving within 30 min. Distal cerebral protection with the FilterWire during carotid stenting is feasible and safe, results in capture and extraction of atheroembolic debris in the majority of patients while affording uninterrupted cerebral perfusion, and in this initial multicenter experience was associated with a high rate of procedural success without major complications. Cathet Cardiovasc Intervent 2003;58:139–146. © 2003 Wiley‐Liss, Inc
The efficacy of using pulmonary vein wedge pressure for the estimation of pulmonary artery pressure in children with congenital heart disease
Authors: Toyono Manatomo , Harada Kenji , Tamura Masamichi , Yasuoka Kenji , Oyama Tomomi , Takada Goro
Published: January 2003

The objectives of this study were to assess the accuracy of pulmonary vein wedge pressure (PVWP) in estimating pulmonary artery pressure (PAP) in various types of congenital heart disease, including single‐ventricle physiology. The systolic, diastolic, and mean values of both PAPs and PVWPs were measured in 30 patients (a total of 46 points). Pulmonary artery pressure ranged from 13 to 74 (34 ± 15) mm Hg in systole, 5 to 25 (13 ± 6) mm Hg in diastole, and 6 to 48 (18 ± 10) mm Hg in mean. As a whole, good correlations between PAPs and PVWPs were observed (systole, r = 0.70; diastole, r = 0.85; mean, r = 0.82; P < 0.0001). However, with an increase in PAP, the discrepancy between PAPs and PVWPs increased. When the mean PVWP was more than 18 mm Hg, the mean PVWP in 14 of 24 (58%) underestimated the mean PAP by up to 22 mm Hg (mean difference, −1.7 ± 5.8 mm Hg). On the other hand, all of the patients with mean PVWPs less than 18 mm Hg (n = 22) had mean PAPs less than 18 mm Hg (r = 0.86; PAP = 1.11 × PVWP − 1.41; P < 0.0001), and the mean difference was −0.2 ± 1.8 mm Hg. The mean PVWP can accurately estimate the mean PAP in children with congenital heart disease who have a mean PVWP less than 18 mm Hg. Cathet Cardiovasc Intervent 2003;58:232–237. © 2003 Wiley‐Liss, Inc.
Directional coronary atherectomy vs. rotational atherectomy for the treatment of in‐stent restenosis of native coronary arteries
Authors: Sanchez Pedro L. , Rodriguez‐Alemparte Maximo , Colon‐Hernandez Pedro J. , Pomerantsev Eugene , Inglessis Ignacio , Mahdi Nasser A. , Leinbach Robert C. , Palacios Igor F.
Published: January 2003

Management of in‐stent restenosis has become a significant challenge in interventional cardiology. Since the mechanism of in‐stent restenosis is predominantly intimal hyperplasia, debulking techniques have been used to treat this condition. This study is a nonrandomized comparison of the immediate and long‐term results of directional coronary atherectomy (DCA; n = 58) vs. high‐speed rotational atherectomy (ROTA; n = 61) for the treatment of in‐stent restenosis of native coronary arteries. There were no in‐hospital deaths, Q‐wave myocardial infarctions, or emergency coronary artery bypass surgery in either group. DCA resulted in a larger postprocedural minimal luminal diameter of (2.57 ± 0.51 vs. 2.14 ± 0.37 mm; P < 0.0001) and a larger acute gain (1.83 ± 0.52 vs. 1.42 ± 0.48 mm; P < 0.0001). Furthermore, 12‐month clinically indicated target lesion revascularization (39% vs. 21%; P = 0.02) and long‐term follow‐up MACE (44% vs. 28%; P = 0.03) was greater in the ROTA group. The present study suggests that DCA appears to be superior to ROTA for the treatment of in‐stent restenosis of native coronary arteries. Compared to ROTA, the debulking effect of DCA leads to a larger postprocedure minimal luminal diameter, and a lower incidence of subsequent target lesion revascularization and MACE. Cathet Cardiovasc Intervent 2003;58:155–161. © 2003 Wiley‐Liss, Inc.
Balloon angioplasty and stenting of multiple intralobar pulmonary arterial stenoses in adult patients
Authors: Rothman Abraham , Levy Denis J. , Sklansky Mark S. , Grossfeld Paul D. , Auger William R. , Ajami Gholam H. , Behling Cynthia A.
Published: January 2003

Balloon angioplasty and stent placement for pulmonary arterial stenoses in children are well‐established therapies. In contrast, management of isolated peripheral pulmonary arterial stenoses in adults remains relatively unexplored. Four women (ages 18–63 years) with multiple discrete intralobar pulmonary arterial stenoses were treated with balloon angioplasty. Initially, 4–5 stenoses were dilated in each patient. The mean minimum diameter of the stenoses increased from 1.3 to 3.1 mm (P < 0.001), and the mean ratio of right ventricular to aortic systolic pressure decreased from 0.92 to 0.62 (P < 0.05). Each patient had marked symptomatic improvement. However, three patients developed recurrence of symptoms 4–24 months after angioplasty, and two had angiographic evidence of restenosis at previously dilated sites. These restenoses were treated with repeat angioplasty or stent implantation (three stents in each patient). One of these two patients developed near‐occlusive restenosis of the stents and had successful bilateral lung transplantation. The other patient had a third catheterization with successful implantation of three additional stents. The third patient with recurrent symptoms died 2 years later, without further intervention. Transcutaneous catheter therapy for multiple intralobar pulmonary arterial stenoses in adults is highly successful acutely, but restenosis is common within several months. For some patients, balloon angioplasty and stent implantation may provide definitive management, while for others these procedures may serve as a bridge to lung transplantation. Cathet Cardiovasc Intervent 2003;58:252–260. © 2003 Wiley‐Liss, Inc.
Transcatheter occlusion of patent ductus arteriosus using a new angled Amplatzer duct occluder: Initial clinical experience
Authors: Masura Jozef , Gavora Pavol , Podnar Tomaž
Published: January 2003

In the present study, we report the initial clinical experience with the new angled Amplatzer duct occluder (ADO) for the percutaneous closure of patent ductus arteriosus (PDA). Percutaneous closure of PDA using standard ADO in infants and in patients with small PDA ampulla is difficult, or even impossible, due to protrusion of the aortic disk into the descending thoracic aorta. The aortic disk of an angled ADO is angled at 32° to the body of the device and concave toward the aorta to prevent protrusion of the disk into the aorta. Percutaneous closure of PDA was attempted in nine patients with a median age of 5.2 years (range, 0.5–12.7) and median weight of 20 kg (range, 4.9–55). Selection of the occluder and the implantation technique were similar to the standard ADO. The minimal PDA diameter ranged from 2.1 to 3.7 mm (median, 2.5 mm). Occluders were successfully implanted in all patients. Immediate complete PDA closure was achieved in all patients. There were no complications. The new angled ADO is a safe and effective device for PDA closure, particularly suitable for infants and patients with small PDA ampulla. Further studies and long‐term follow‐up are necessary to confirm our initial experience. Cathet Cardiovasc Intervent 2003;58:261–267. © 2003 Wiley‐Liss, Inc.