bluuebunny/crossref_metadata_2025_split huggingface dataset:
Confined blood chimerism in monochorionic dizygous (MCDZ) twins
Authors: Walker Susan P. , Meagher Simon , White Susan M. 
Published: February 2007

AbstractObjectiveTo present the risk factors, prenatal and postnatal implications of monochorionic dyzygotic twinning.MethodsWe present a case of monochorionic twins diagnosed on first‐trimester ultrasound following a 2‐embryo transfer in vitro fertilisation pregnancy. Postnatal buccal smears performed as part of a twin research study revealed the twins to be dizygous, and DNA testing on peripheral blood lymphocytes confirmed the presence of blood chimerism.ResultsDespite the monochorionic placentation, buccal swabs revealed discordant results for all four microsatellite loci tested, consistent with dizygosity. Zygosity testing on peripheral blood lymphocytes revealed that, of the nine DNA microsatellite loci tested, three had all four parental alleles represented. This result was concordant between the twins. The diagnosis of blood chimerism was thus confirmed, presumably due to the inter‐twin vascular anastomoses of the monochorionic placenta.ConclusionMonochorionic dizygous twinning is rare, but appears to be more common after assisted reproduction. It is presumed that outer cell mass fusion may occur when two embryos are replaced in close proximity. These pregnancies are not only at risk for the usual complications of monochorionicity, but also have the potential to be heterokaryotypic. Postnatally, the twins may have long‐term blood chimerism. Copyright © 2007 John Wiley & Sons, Ltd.
Microphthalmia with linear skin defects (MLS) syndrome evaluated by prenatal karyotyping, FISH and array comparative genomic hybridization
Authors: Cain Colyn Cargile , Saul Daniel , Attanasio Lisa , Oehler Erin , Hamosh Ada , Blakemore Karin , Stetten Gail 
Published: February 2007

AbstractObjectiveTo explore the utility of comparative genomic hybridization to BAC arrays (array CGH) for prenatal diagnosis of microphthalmia and linear skin defects syndrome.MethodsWe used karyotype analysis, FISH and array CGH to investigate an X;Y translocation. Replication studies were done on cultured amniocytes and lymphoblasts.ResultsWe describe a severe case of MLS syndrome that presented prenatally with multiple anomalies including cystic hygroma, microphthalmia, intrauterine growth restriction and a complex congenital heart defect. Cytogenetic analysis of amniocytes revealed an unbalanced de novo translocation between chromosomes X and Y [karyotype 46,X,der(X)t(X;Y)(p22.3;q11.2).ish der(X)(DXZ1+,DMD+,KAL−,STS−,SRY−),22q11.2 (Tuple1 × 2)]. MLS diagnosis was made at birth and the prenatal karyotype was confirmed. Replication studies showed the derivative X chromosome was the inactive X. Array CGH confirmed the X and Y imbalances seen in the karyotype and also showed twelve BACs in the MLS region were deleted as a result of the translocation. FISH with BAC clones verified the array findings and placed the X breakpoint in Xp22.2, resulting in the amended karyotype, 46,X,der(X)t(X;Y)(p22.2;q11.2).ish der(X)(DXZ1+,DMD+,KAL−,STS−,SRY−),22q11.2(Tuple1 × 2) arr cgh Xp22.33p22.2(LLNOYCO3M15D10 →GS1‐590J6)× 1,Yq11.222q23(RP11‐20H21→RP11‐79J10)× 1.ConclusionThe sensitivity of array CGH was valuable in detecting monosomy of the MLS critical region. Array CGH should be considered for the prenatal diagnosis of this syndrome. Copyright © 2007 John Wiley & Sons, Ltd.
Complete discrepancy between QF‐PCR analysis of uncultured villi and karyotyping of cultured cells in the prenatal diagnosis of trisomy 21 in three CVS
Authors: Waters Jonathan J. , Mann Kathy , Grimsley Lee , Ogilvie Caroline Mackie , Donaghue Celia , Staples Leonie , Hills Alison , Adams Tracey , Wilson Christine 
Published: February 2007

AbstractObjectiveTo investigate complete discrepancies in the prenatal diagnosis of trisomy 21 between QF‐PCR analysis of uncultured villi and karyotyping of cultured cells in three chorion villus samples.MethodsClinical details were obtained from all three patients. Follow‐up studies were undertaken where possible by evaluation of chromosome 21 copy number with QF‐PCR, interphase FISH, MLPA and karyotyping, and by post‐mortem examination.ResultsCase 1: severe oligohydramnios and microcephaly on scan. QF‐PCR: trisomy 21; MLPA: trisomy 21; cultured karyotype: 46,XY[48]. Placental and fetal tissue results and post‐mortem examination indicated a euploid fetus with trisomy 21 mosaicism confined to the placenta. Case 2: Down screen risk 1:16; NT = 4.4 mm; absent nasal bone (Caucasian mother). QF‐PCR: disomy 21; cultured karyotype: 47,XY,+ 21[23]. Neck thickening noted at delivery—post‐mortem refused, no fetal tissue available. Placental tissue indicated mosaicism for trisomy 21. Case 3: Down screen risk 1:91; NT = 6.7 mm. QF‐PCR: disomy 21; cultured karyotype: 46,XX,der(21;21)(q10;q10)[60]. No follow‐up possible. PCR genotyping of cultured cells confirmed sample identity in all three cases. Chromosome 21 markers observed by PCR were biallelic in all three cases, indicating that a mitotic error could account for the presence of the abnormal cell lines in each case.ConclusionQF‐PCR analysis of uncultured villi and cultured karyotyping may rarely show complete discrepancy in the prediction of fetal trisomy 21 in CVS. Within‐biopsy sample mosaicism, together with the testing of different cell populations, provide an explanation for these results. Practical ways to minimise the risk of such discrepancy are proposed. Copyright © 2007 John Wiley & Sons, Ltd.
Free fetal DNA in maternal plasma in anembryonic pregnancies: confirmation that the origin is the trophoblast
Authors: Alberry M. , Maddocks D. , Jones M. , Abdel Hadi M. , Abdel‐Fattah S. , Avent N. , Soothill P. W. 
Published: February 2007

AbstractObjectiveTo test the hypothesis that free fetal DNA (ffDNA) circulating in maternal plasma originates mainly from the placenta we studied ffDNA levels in anembryonic pregnancies.MethodsMaternal blood samples were collected from 15 normal first‐trimester pregnancies in which fetal sex was subsequently determined and nine patients with a diagnosis of anembryonic gestation (AG). The Y chromosome DYS14 gene was quantified by real‐time quantitative PCR (RT‐PCR) for the determination of fetal sex in both plasma and chorionic tissue samples. Fetal sex in chorionic tissue samples was also determined using quantitative fluorescence PCR (QF‐PCR).ResultsThe correct sex result was obtained from maternal plasma in all. Four AG pregnancies were female (DYS14 negative) results. In five of the AG cases, the chorionic tissue was found to be male (by both QF‐PCR and RT‐PCR which agreed) and positive male signal was found in maternal plasma by RT‐PCR. There was no statistical difference between median free fetal DNA concentration in plasma between the AG male cases (148.3 GE/mL) and controls (145.8 GE/mL).ConclusionSince ffDNA levels are normal in pregnancies without a fetus, the data support the hypothesis that the trophoblastic cells are the major source ffDNA in maternal plasma. Copyright © 2007 John Wiley & Sons, Ltd.
Statins and fracture risk. A systematic review
Authors: Toh Sengwee , Hernández‐Díaz Sonia 
Published: February 2007

AbstractPurposeTo summarize current evidence on statin use and fracture risk and to explore potential sources of heterogeneity among study results.MethodsA computerized search was conducted on MEDLINE, EMBASE, and the Cochrane databases using the keywords HMG‐CoA reductase inhibitor, osteoporosis, and fractures. A meta‐analysis was performed to summarize results of studies identified.ResultsStatin use was associated with a 23% lower fracture risk (OR = 0.77, 95%CI: 0.66–0.90). An effect of statins was found in case‐control (OR = 0.62, 0.45–0.85, n = 6) and cohort (OR = 0.77, 0.59–1.00, n = 8) studies, but not in post hoc analyses of randomized trials (OR = 1.03, 0.91–1.16, n = 4). A reduced risk with statin use was found for fractures of the hip (OR = 0.58, 0.46–0.74, n = 16), spine (OR = 0.65, 0.48–0.88, n = 8) and other sites (OR = 0.77, 0.60–1.00, n = 7), and both in women (OR = 0.80, 0.66–0.96, n = 11) and men (OR = 0.62, 0.36–1.08, n = 3). Among the observational studies that also evaluated the effect of other lipid‐lowering drugs, no reduced fracture risk was found for these agents (OR = 0.96, 0.85–1.09, n = 10). The test for heterogeneity was significant for study results of statin use versus no‐use (p < 0.01). Meta‐regression analyses suggested that study design might partly account for the heterogeneity. There was an indication of publication bias by examining Begg's plot, although Egger's test was not significant (p = 0.13).ConclusionsCurrent evidence does not support an effect of statins in preventing fractures given (i) the lack of association in randomized trials, (ii) the heterogeneity among observational studies, (iii) the potential residual confounding, and (iv) the potential publication bias. Copyright © 2007 John Wiley & Sons, Ltd.
Clinical interest: a study of the influence on general practitioners' prescribing
Authors: Hansen Dorte Gilså , Dybdahl Torben , Jarbøl Dorte , Vach Werner 
Published: February 2007

AbstractPurposeTo analyse the association between general practitioners' clinical interest and prescribing rates in four clinical areas: dyspepsia, depression, headache and diabetes.MethodsData concerning general practitioners' prescribing during 2004 were retrieved from a pharmacy database and linked with data from a physician questionnaire and the National Health Insurance Register. To counterbalance differences in practice populations all 1‐year prevalences of prescribing were standardised according to age and gender. Participants were asked ‘To what extent do you find the following areas interesting from a professional point‐of‐ view?’ Four rating categories were used. The association between clinical interest and standardised prescribing rates was investigated using logistic regression, the Kruskal‐Wallis test and a trend test.ResultsA total of 68 (72%) single‐handed general practitioners representative of the total group completed the questionnaire. We observed a two‐fold ratio between the 90% and the 10% percentiles of the 1‐year prevalences of antisecretory drugs, antidepressants, migraine drugs as well as anti‐diabetics. The variation in prescribing of antidepressant and antisecretory drugs was far above chance level. No significant association with clinical interest could, however, be observed for any of the four clinical areas.ConclusionGeneral practitioners' prescribing of the four classes of medical drugs varied considerably. However, only part of this variation was based on chance. This study did not confirm our hypothesis that general practitioners' level of clinical interest in one area corresponds with their prescribing of drugs used within that area. Copyright © 2007 John Wiley & Sons, Ltd.
Inadequacy of fluconazole dosing in patients with candidemia based on Infectious Diseases Society of America (IDSA) guidelines
Authors: Garey Kevin W. , Pai Manjunath P. , Suda Katie J. , Turpin Robin S. , Rege Milind D. , Mingo Dana E. , Bearden David T. 
Published: February 2007

AbstractIntroductionBased on Infectious Diseases Society of America (IDSA) guidelines, inappropriate fluconazole therapy in patients with candidemia is defined as an empiric dose <6 mg/kg/d, <12 mg/kg/d after Candida glabrata identification, or continued fluconazole use after identification of Candida krusei. However, the extent to which inappropriate antifungal therapy is due to improper dosing or drug selection has not been well investigated. The objectives of this study were to assess the incidence of inappropriate fluconazole therapy in patients with candidemia and to identify variables associated with inappropriate therapy.MethodsRetrospective cohort study from four medical centers of hospitalized patients with candidemia prescribed fluconazole. Appropriateness of fluconazole dosages (adjusted for renal dysfunction) was assessed at the time of symptom onset and after Candida identification.ResultsPatients (206) were identified. Sixty‐one of 112 (55%) patients who were given empiric therapy received an initial dose of fluconazole <6 mg/kg. After identification of the Candida species, 97 of 206 (47%) patients received inadequate fluconazole therapy based on IDSA guideline recommendations due to a fluconazole dose <12 mg/kg after isolation of C. glabrata (12%), continued use of fluconazole after isolation of C. krusei (3%), or a dose <6 mg/kg for all other Candida species (32%).Using multivariate logistic regression, increased weight in 1‐kg increments (OR: 1.02; p = 0.0142) and a creatinine clearance (CRCL) >50 ml/minute (OR: 3.17; p = 0.0003) were associated with increased risk of inadequate fluconazole therapy.ConclusionA high prevalence of suboptimal dosing of fluconazole given empirically or after Candida species identification was documented. Increased weight and CRCL were significant predictors of inadequate fluconazole doses. Copyright © 2007 John Wiley & Sons, Ltd.
Fetal growth and congenital malformations
Authors: Nikkilä A. , Källén B. , Maršál K. 
Published: February 2007

AbstractObjectivesTo ascertain whether the risk for congenital malformations is increased in pregnancies with deviating fetal growth, i.e. in those in which the estimated date of delivery (EDD) was postponed more than 1 week at the second‐trimester ultrasound fetometry scan, or those suspected of intrauterine growth restriction at routine ultrasound fetometry in the third trimester.MethodsThe study period was 1994–2003. We used the Swedish Medical Birth Register to identify pregnancies with appropriate data (n = 605 845). A regional ultrasound database consisting of 73 092 pregnancies was used for more detailed data and analysis of the third‐trimester fetal growth. The number of congenital malformations was ascertained from three national health registers.ResultsWe found a moderately increased risk for any malformation in the group of fetuses in which the EDD was postponed > 1 week. The strongest effect was seen for chromosome anomalies and central nervous system malformations, including neural tube defects. In the third trimester, an increased risk for fetal malformations was found in asymmetrically vs. symmetrically growth‐restricted fetuses, perhaps more strongly when adjustment of the EDD had been done at the dating scan.ConclusionsFetuses in which the EDD differs between that calculated by the last menstrual period and that calculated by second‐trimester ultrasound measurement seem to have an increased risk for congenital malformations, including chromosomal anomalies. A targeted ultrasound examination for malformation screening might be recommended for this group. A similar policy might be recommended when intrauterine growth restriction, especially of the asymmetrical type, is suspected later in pregnancy. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Clinical and ultrasound estimation of birth weight prior to induction of labor at term
Authors: Peregrine E. , O'Brien P. , Jauniaux E. 
Published: February 2007

AbstractObjectivesTo assess and compare the accuracy of clinical and sonographic fetal weight estimation in predicting birth weight prior to induction of labor.MethodsIn a prospective study of 262 women immediately prior to induction of labor, the fetal weight was estimated clinically by both the doctor (DR EFW) and the woman herself (WM EFW). A transabdominal scan was then performed to estimate the fetal weight sonographically using two different formulae—Shepard (SHEP EFW) and Hadlock (HAD EFW). The four estimated fetal weights were compared with the actual birth weight.ResultsThe mean percentage error was − 1.9 ± 9.3% for DR EFW, − 3.4 ± 12.6% for WM EFW, − 2.3 ± 11.6% for SHEP EFW and − 7.6 ± 10.6% for HAD EFW. All four EFWs were significantly different from birth weight (t = − 4.7, − 5.5, − 3.5 and − 11.4, respectively, all P < 0.01). The corresponding proportion of the EFWs which were within 10% of birth weight were 71%, 59%, 62% and 42%, respectively. The sensitivity and specificity of detecting a fetus weighing < 3000 g were 56% and 98% for DR EFW, 90% and 89% for WM EFW, 93% and 83% for SHEP EFW and 100% and 76% for HAD EFW. The corresponding values for detecting a fetus weighing > 4000 g were 16% and 99%, 29% and 96%, 48% and 92% and 40% and 94%, respectively.ConclusionsAlthough, in general, clinical estimates of birth weight perform favorably compared with ultrasonographic estimates, ultrasound immediately prior to labor is more accurate at predicting the low‐ or high‐birth‐weight fetus. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Superior balance of weatherability and impact performance with acrylic‐capped vinyl siding
Authors: Szamborski Gene 
Published: February 2007

AbstractVinyl siding, particularly in darker colors, has to be durable and be able to retain most of its original color when exposed outdoors. As the color palette for vinyl siding has been expanding and more and more colors are being offered to the homeowner, the need exists to improve color hold. A new acrylic capstock polymer, based on core‐shell technology, which can be coextruded onto vinyl siding, has been shown to provide excellent color retention, with good processability, impact and impact retention, and suitable gloss. The properties of this new capstock polymer are compared to other choices for capping vinyl siding. J. VINYL ADDIT. TECHNOL., 13:26–30, 2007. © 2007 Society of Plastics Engineers.
Kaliumpolysulfide: [K(THF)]2S6 und [K2(THF)]S9
Authors: Dornhaus Franz , Bolte Michael , Wagner Matthias , Lerner Hans‐Wolfram 
Published: February 2007

AbstractPotassiumpolysulfides: [K(THF)]2S6 and [K2(THF)]S9The polysulfide [K2(THF)]S9 is accessible from reaction of S8 with [KSPPh2(BH3)]. Degradation reaction of S8 with [KPPh2(BH3)] results in [K(THF)]2S6. X‐ray quality crystals of [K(THF)]2S6 (orthorhombic, Pbca) and of [K2(THF)]S9 (orthorhombic, Pbcm) are obtained each from THF / diethyl ether solution at ambient temperature. According to the result of the X‐ray structural analysis, [K(THF)]2S6 and [K2(THF)]S9 contain a S6‐ and S9‐zigzag chain. The conformation of both polysulfide anions is all‐transoid.
Synthesis and Crystal Structures of Octahedral Metal Complexes containing the New Dianion [PhP(Se,O)Se‐Se(O,Se)PPh]2−
Authors: Shi Weifeng , Zhang Le , Shafaei‐Fallah Maryam , Rothenberger Alexander 
Published: February 2007

AbstractThe synthesis and structures of three new compounds are reported. [Mg2{PhP(Se,O)Se‐Se(O,Se)PPh}2(thf)7(H2O)3] (1), [Mg{PhP(Se,O)Se‐Se(O,Se)PPh}(thf)3(H2O)] (2), and [Mn{PhP(Se,O)Se‐Se(O,Se)PPh}(thf)3(H2O)] (3) were prepared by treatment of Woollins' reagent [PhP(Se)(μ‐Se)]2 with the corresponding hydrated metal acetates.
Zur Elektronenstruktur metallorganischer Komplexe der f‐Elemente. 65 Erstmalige Beobachtung des linearen Dichroismus bei einem homoleptischen metallorganischen π‐Komplex der f‐Elemente: Tris(η5‐tetramethylcyclopenta‐dienyl)neodym(III)
Authors: Amberger Hanns‐Dieter , Reddmann Hauke 
Published: February 2007

AbstractElectronic Structures of Organometallic Complexes of f Elements. 65 First Observation of Linear Dichroism of a Homoleptic Organometallic π Complex of f Elements: Tris(η5‐tetramethylcyclopentadienyl)neodymium(III)The absorption spectrum of a powder sample of pseudo (Ψ) trigonal planar Nd(η5‐C5Me4H)3 (1) has been measured at room temperature and ca. 40 K, respectively, and the linear dichroism spectra of σ‐ and π‐type of an oriented single crystal at ambient temperature and 77 K. Neglecting the signals of the C–H combination vibrations and overtones extracted from the absorption spectrum of La(η5‐C5Me4H)3 (2), the observed polarization properties of the remaining f‐f transitions allowed the derivation of a truncated crystal field splitting pattern. The free parameters of a phenomenological Hamiltonian were fitted to this pattern leading to a reduced r.m.s. deviation of 16.1 cm−1 for 38 assignments. The temperature dependence of the paramagnetic susceptibility of 1 was calculated, making use of the crystal field energies and wavefunctions of the fit. Introducing an orbital reduction factor of 0.98, calculated values of 1 agree well with the experimental ones of Ψ trigonal planar Nd(C5H4tBu)3.
Monomeric Homoleptic (2‐Pyridylmethyl)(tert‐butyldimethylsilyl)amido Complexes of the Divalent Metals Mg, Mn, Fe, Co, and Zn
Authors: Koch Christian , Malassa Astrid , Agthe Christine , Görls Helmar , Biedermann Ralf , Krautscheid Harald , Westerhausen Matthias 
Published: February 2007

AbstractThe transamination reaction of M[N(SiMe3)2]2 with (2‐pyridylmethyl)(tert‐butyldimethylsilyl)amine yields the corresponding homoleptic metal bis[(2‐pyridylmethyl)(tert‐butyldimethylsilyl)amides] of Mg (1), Mn (2), Fe (3), Co (4) and Zn (5). All these compounds crystallize from hexane isotypic in the space group C2/c. From toluene the zinc derivative precipitates as toluene solvate 5·toluene. The molecular structures of these compounds are very similar with large NMN angles to the amide nitrogen atoms with NMN values of 148° (1) and 150° (5) for the diamagnetic compounds and 156° for the paramagnetic derivatives 2 and 3. The Co derivative 4 displays a rather small NCoN angle of 142°. Different synthetic routes have been explored for compound 3 which is also available via the metallation reaction of bis(2,4,6‐trimethylphenyl)iron with (2‐pyridylmethyl)(tert‐butyldimethylsilyl)amine and via the metathesis reaction of lithium (2‐pyridylmethyl)(tert‐butyldimethylsilyl)amide with [(thf)2FeCl2]. In course of the metathesis reaction, an equimolar amount of lithium (2‐pyridylmethyl)(tert‐butyldimethylsilyl)amide and [(thf)2FeCl2] yields heteroleptic (2‐pyridylmethyl)(tert‐butyldimethylsilyl)amido iron(II) chloride (6) which crystallizes as a centrosymmetric dimeric molecule. The oxidative C‐C coupling reaction of 5 with Sn[N(SiMe3)2]2 leads to the formation of tin(II) 1,2‐bis(2‐pyridyl)‐1,2‐bis(tert‐butyldimethylsilylamido)ethane, tin metal and Zn[N(SiMe3)2]2.
Copper(II) Complexes of ω‐Hydroxy‐Functionalized N‐Salicylidenehydrazides show pH‐Controlled Switching between Dicationic Dimers and Neutral One‐Dimensional Coordination Polymers
Authors: Roth Arne , Buchholz Axel , Plass Winfried 
Published: February 2007

AbstractNew copper(II) complexes of the hydrazone ligands H2salhyhb, H2salhyhp, and H2salhyhh, derived from salicylaldehyde and ω‐hydroxy carbonic acid hydrazides, have been synthesized and physically characterized. Two fundamental structures were found in solid state depending on the pH‐value of the reaction solution. Acidic conditions lead to the formation of the di‐μ‐phenoxo‐bridged dicationic complex dimers [{Cu(Hsalhyhb)}2]2+ (1a), [{Cu(Hsalhyhp)}2]2+ (2a), and [{Cu(Hsalhyhh)}2]2+ (3a), isolated as perchlorate salts. The dimeric complexes show strong antiferromagnetic coupling with J = −399 (1a), −410 (2a), and −311 cm−1 (3a). Higher pH‐values resulted in the aggregation of neutral copper ligand fragments to the one‐dimensional coordination polymers [{Cu(salhyhb)}n] (1b), [{Cu(salhyhp)}n] (2b), and [{Cu(salhyhh)}n] (3b). 3b has been examined by means of X‐ray crystallography and represents the first example of a structurally characterized neutral copper(II) N‐salicylidenehydrazide complex without additional ligands. The magnetic interactions in the polymers are also antiferromagnetic with J = −125 (1b), −136 (2b), and −148 cm−1 (3b), but strongly reduced compared to the corresponding dimeric complexes. The two basic structure types can be reversibly interconverted simply by pH‐control.