bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enantiodifferentiation of isomeric vitispiranes
Authors: Herion P. , Full G. , Winterhalter P. , Schreier P. , Bicchi C. 
Published: March 2007

AbstractTwo optically enriched theaspirone isomers, i.e. (2S,5S)‐( − )‐theaspirone 2b and (2S,5R)‐( + )‐theaspirone 2c (ee‐values: 86% and 88% respectively), were obtained from quince juice by solvent extraction, flash chromatography and subsequent preparative high performance liquid chromatography (HPLC). Their absolute stereochemistry was assigned by circular dichroism spectroscopy. LiAlH4 reduction of 2b and 2c yielded 8‐hydroxytheaspirane isomers 3b and 3c which were subjected to thermal treatment at pH 3 leading to vitispirane isomers 1b and 1c. In the same manner, vitispirane racemates 1a/1b and 1c/1d were obtained from the synthetic theaspirones 2a/2b and 2c/2d which had been separated by multi‐layer coil countercurrent chromatography/HPLC. The optically enriched reference compounds were used to determine the order of elution in the course of enantio‐separation of 1a‐1d which was achieved by multidimensional gas chromatography (MDGC) using DB‐Wax and 2,6‐dimethyl‐3‐pentyl‐β‐cyclodextrin capillary columns. Using on‐line coupled MDGC‐mass spectrometry in the single ion monitoring mode, enantiodifferentiation of 1a‐1d as well as 2a‐2d from a number of natural sources was performed.
Screening of seed lipids for γ‐linolenic acid: Capillary gas‐liquid chromatographic separation of 18:3 fatty acids with Δ5 and Δ6 double bonds
Authors: Aitzetmüller K. , Werner Gisela , Tsevegsüren Nansadyn 
Published: March 2007

Abstractγ‐Linolenic acid (6c,9c,12c‐18:3) has recently become important for dietary and pharmaceutical applications. The reported occurrence of γ‐linolenic acid in seed oils from plant families known to produce fatty acids, including 18:3 acids, with Δ5‐cis and Δ5‐trans double bonds makes it necessary to distinguish between 5c,9c,12c‐, 5t,9c,12c‐ and 6c,9c,12c‐octadecatrienoic acids by gas chromatography (GC) alone in routine screening operations. The separation of these acids using two different capillary GC systems has been investigated. The successful separation of octadecatrienoic acids with 5c, 5t and 6c double bonds is shown by way of gas chromatograms of the fatty acid methyl esters obtained from the seed oils of four different species of the family Ranunculaceae and of Xeranthemum and Pinus.
Analysis of secondary metabolites from Lichen by high performance liquid chromatography with a photodiode array detector
Authors: Yoshimura Isao , Kinoshita Yasuhiro , Yamamoto Yoshikazu , Huneck Siegfried , Yamada Yasuyuki 
Published: March 2007

AbstractSecondary metabolites from Lichen, mainly phenolic compounds, have been analysed and identified using high performance liquid chromatography with a photodiode array detector. Components of lichen thalli were detected by characteristic ultraviolet spectra and relative retention times. Some new minor components have been found in several lichens.
A simple spectrophotometric assay for plant 5′‐deoxy‐5′‐methylthioadenosine nucleosidase using xanthine oxidase as a coupling enzyme
Authors: Dunn Steven M. , Bryant John A. , Kerr Michael W. 
Published: March 2007

AbstractThe first step in the metabolic salvage of methionine from 5′‐deoxy‐5′‐methylthioadenosine, generated as a by‐product of polyamine and ethylene biosynthesis, is the hydrolytic cleavage of the adenine base from the pentose sugar by a specific nucleosidase. A continuous coupled assay procedure for this enzyme has been developed which exploits the ability of xanthine oxidase to utilise free adenine as a substrate and represents a convenient alternative to pre‐existing radioisotopic methods. Two variations of the basic technique are described and their suitability both for routine chromatographic monitoring and for more stringent kinetic analyses is discussed. Kinetic data obtained via this procedure for the methylthioadenosine nucleosidase enzyme from Pisum sativum was shown to be consistent with previously published data.
Factors involved in the high pressure liquid chromatographic separation of alkenes by means of argentation chromatography on ion exchangers: Overview of theory and new practical developments
Authors: van Beek Teris A. , Subrtova Dana 
Published: March 2007

AbstractThe literature on the use and theory of silver(I) complexation (argentation) chromatography is reviewed. Apolar isomeric alkenes, for example numerous terpenes and fatty acids, can be well resolved by means of high pressure liquid chromatography on cation exchange materials coated with silver(I) ions, but unfortunately the mechanism on which these separations are based is not fully understood. As part of an attempt to provide a predictive model for the separation of volatile alkenes, the retention of more than 40 C2‐C10 olefins besides a number of C14‐pheromones and volatile terpenes is given and the results discussed. The separation is mainly governed by the type and number of double bonds (isolated, conjugated or aromatic), their steric accessibility (number and size of substituents) for complexation with silver(I) ions, the relief of inherent strain upon complexation and electron donating or withdrawing groups, or polar groups close to the double bond. Polar groups such as hydroxyls also complex weakly with silver. Other functional groups, including carbonyls, and the overall polarity of the solute play only a minor role. Similarly most solvents have only a limited influence on the selectivity and speed of separation, and function more as a transportation medium as in gas chromatography. A comparative model which gives semi‐quantitative estimations of the retention time of most volatile olefins in methanol is presented. Substituent parameters (Ags) which quantitatively forecast the influence of different alkyl side chains are part of this model.
Prenatal diagnosis of thalassemia major by fetal blood analysis: Experience with 1000 cases
Authors: Cao Antonio , Falchi Angela M. , Tuveri Teresa , Scalas Maria T. , Monni Giovanni , Rosatelli Cristina 
Published: March 2007

AbstractIn this report we have summarized our experience with the prenatal diagnosis of β‐thalassemia in 1000 pregnancies followed at least until 12 months after birth. In the majority of these cases, the thalassemia lesion was the nonsense mutation at the codon corresponding to amino acid 39, which produces the hematological phenotype of β‐thalassemia. Fetal blood sampling was carried out by placental aspiration, by which a sufficient amount of fetal blood for analysis was obtained in the majority of cases (99 per cent). The fetal mortality associated with fetal blood sampling was 6·3 per cent. Those placental samples contaminated by maternal cells were successfully purified by Ørskov lysis. Fetal blood was analysed by globin chain synthesis on CM–52 columns, which gave reliable results. Two misdiagnoses (0·2 per cent) have been made of which one was due to a non‐globin protein co‐migrating with the β‐chains while the other resulted from a misclassification of the type of thalassemia segregating in the family.
Adult‐onset GM2 gangliosidosis diagnosed in a fetus
Authors: Navon R. , Sandbank U. , Frisch A. , Baram D. , Adam A. 
Published: March 2007

AbstractAmniocentesis and subsequent tests are reported on a fetus conceived of a rare mating type: its mother has an intermediate level of β hexosaminidase A (HEX A), characteristic of carriers of Tay‐Sachs disease (TSD), while the father suffers from an adult‐onset GM2 ganglio‐sidosis (AOG) with severe HEX A deficiency. Activity of HEX A in the cultured fetal cells was very low when measured by the heat‐inactivation method, thus showing the typical biochemical phenotype of TSD fetuses. However, upon separation of HEX isozymes by ion exchange chromatography, residual HEX A (17 per cent of total HEX) was demonstrated. Also in contrast to TSD fetuses, this fetus' fibroblasts were able to synthesize the precursor of a chains of HEX, and ultrastructural examination of its brain revealed few atypical lamellar bodies, unlike those found in TSD fetuses of the same gestational age. It is therefore concluded that the fetus was not affected with TSD, but rather with AOG.
Activity of biotin‐dependent and gaba metabolizing enzymes in chorionic villus samples: Potential for 1st trimester prenatal diagnosis
Authors: Sweetman Frances R. , Gibson Kenneth M. , Sweetman Lawrence , Nyhan William L. , Chin Homer , Swartz William , Jones Oliver W. 
Published: March 2007

AbstractWe have documented the presence of five mitochondrial enzymes in samples of chorionic villus tissue and measured the levels of activity. Three of the enzymes catalyse biotindependent reactions. These are propionyl‐CoA carboxylase, 3‐methylcrotonyl‐CoA carboxylase and pyruvate carboxylase. the other enzymes. 4‐aminobutyric acid aminotransferase and succinic semialdehyde dehydrogenase, are involved inthe degradation of the central inhibitory neurotransmitter GABA. Distinct diseases in whichthere is deficiency of each of these enzymes have been documented in man. Significant levels of activity were observed for all five enzymes in chorionic villus tissue. This methodology should permit early prenatal diagnosis of deficiencies of these enzymes by chorionic villus biopsy in the first trimester.
Amniotic fluid macrophages from normal and malformed fetuses
Authors: Medina‐Gomez P. , McBride W. H. 
Published: March 2007

AbstractAmniotic fluid cells from normal and abnormal fetuses (neural tube defects and abdominal wall lesions) were examined uncultured and after short‐term culture for macrophages. Morphology, adherence, phagocytosis, presence of Fc receptors and non‐specific esterase were studied. The existence of macrophages in normal and abnormal fluids was confirmed, although the percentage and the absolute numbers varied greatly from specimen to specimen. The most marked increases in total macrophages were in cases of anencephaly. The significance of these macrophages and their value in prenatal diagnosis are discussed.
Possibility of prenatal diagnosis of hereditary triose phosphate isomerase deficiency
Authors: Rosa R. , Prehu M. O. , Calvin M. C. , Daffos F. , Forestier F. 
Published: March 2007

AbstractPrenatal diagnosis has been performed on umbilical cord blood of an 18 weeks fetus of heterozygous triosephosphate isomerase (TPI) deficient parents. After excluding maternal blood contamination, TPI activity was measured and found to be 60 per cent of the normal mean whereas the value of glucose‐6‐phosphate dehydrogenase activity was in the normal range of fetal blood. In addition, the analysis of the characteristics of fetal TPI, i.e. Km measurements for glyceraldehyde‐3‐phosphate, heat stability tests and electrophoretic studies, did not show any evidence of a special form of TPI in fetal blood. These results were consistent with the heterozygous state and were confirmed at birth.
Implications of 'low maternal serum alpha‐fetoprotein levels: Are maternal age risk criteria obsolete?
Authors: Martin Alice O. , Llu Kiang 
Published: March 2007

AbstractAn association has been reported between “low” maternal serum alpha‐fetoprotein (MSAFP) and fetal chromosome abnormalities, notably Down syndrome. We suggest the predictive value be used for genetic counselling when a “low” MSAFP is found, and present an illustrative risk table. It can also be seen that normal MSAFP in a woman may lower her age‐related risks below that previously defined as “high risk”. However, until good estimates of sensitivity and specificity are available from prospective, population based studies, patients should be told that any risk estimates are rough approximations. When good estimates are available, use of age risks alone may become obsolete.
Prenatal ultrasonic diagnosis of familial asymmetric septal hypertrophy
Authors: Stewart Patricia A. , Buis‐Liem Tjik , Verwey Robert A. , Wladimiroff Juriy W. 
Published: March 2007

AbstractHypertrophic cardiomyopathy usually manifests clinically in the second or third decade of life. Two dimensional echocardiography is a reliable indicator of the presence of the disease. This technique is of use in the screening of fetuses at risk for familial cardiomyopathy. This report describes the prenatal echocardiographic detection of hypertrophic cardiomyopathy in the fetus of a mother with hypertrophic cardiomyopathy localized to the apical region of the left ventricle.
Prenatal diagnosis of non‐ketotic hyperglycinemia
Authors: Applegarth D. A. , Levy H. L. , Shih V. E. , McGillivray B. , Wong J. T. , Toone J. R. , Kirby L. T. 
Published: March 2007

AbstractWe describe successful prenatal diagnosis in four pregnancies at risk for non‐ketotic hyperglycinemia, two affected and two unaffected, using the glycine level and the glycine/ serine ratio in amniotic fluid obtained at 16 weeks gestational age. Although this method of prenatal diagnosis for non‐ketotic hyperglycinemia has been effective in our hands the narrow differences between affected and unaffected pregnancies indicate the need for caution concerning its reliability.
Estimation of the weight of chorionic villus samples obtained from first trimester pregnancies by transcervical aspiration
Authors: Newport Melanie , Coleman Dulcie V. , McPherson Klim 
Published: March 2007

AbstractEight obstetricians experienced in chorionic villus sampling were asked to estimate the weight of samples of villi with and without a reference photograph. Referral to the photograph significantly improved the accuracy of their estimations.
Prenatal diagnosis of familial tuberous sclerosis following detection of cardiac rhabdomyoma by ultrasound
Authors: Journel H. , Roussey M. , Plais M. H. , Milon J. , Almange C. , Le Marec B. 
Published: March 2007

AbstractThe authors report a case of tuberous sclerosis (TS), diagnosed by prenatal ultrasound, which was suspected by the detection of intracardiac tumours and confirmed by the family investigation. Cardiac rhabdomyomata can be visualized early on echography and must suggest this diagnosis. The place of genetic counselling and prenatal diagnosis in TS is examined.
Biochemical analysis of meconium in fetuses presumed to have cystic fibrosis
Authors: Brock David J. H. , Barron Lilias 
Published: March 2007

AbstractA series of proteins (albumin, transferrin, a1‐ antitrypsin, alpha‐fetoprotein and pancreatic oncofetal antigen) and enzymes (γ‐glutamyltranspeptidase, aminopeptidase M, alkaline phosphatase, a‐glucosidase and protease) was measured in fetal meconium extracts. There were 19 fetuses thought to have cystic fibrosis (CF), 13 with neural tube defects, three with chromosome abnormalities and 19 normal controls, all with gestational ages between 18 and 21 weeks.With the exception of alpha‐fetoprotein, all the proteins and enzymes were significantly elevated in the CF meconium extracts. The most definitive indicator of a CF fetus was the albumin concentration, where the mean level was five times that found in the control groups. However, five of 19 fetuses assumed to have CF had albumin in the normal range. In these cases the meconium protease levels were grossly elevated. Furthermore, in the same five fetuses meconium concentration of pancreatic oncofetal antigen, a protein synthesized in the fetal pancreas, was also greatly raised.We suggest that post‐mortem examination of a fetus thought to have CF should include measurement of meconium albumin, protease and pancreatic oncofetal antigen.
Prenatal identification of a Y‐chromosome deletion by Y‐specific single copy DNA probes
Authors: Gilgenkrantz S. , Droulle P. , Seboun E. , Casanova M. , Schweitzer M. , Goosens M. , Fellous M. 
Published: March 2007

AbstractA sex chromosome deletion was identified in the course of prenatal diagnosis for maternal age. Ultrasound pictures revealed male fetal sex and a comparison with the father's Y chromosome suggested that the altered chromosome might be a de novo deletion of the Y chromosome. DNA hybridization with five human Y‐specific probes shows that, among the Y‐specific sequences recognized by the probes, only two of them are absent. The normal infant, at birth, was mosaic 46, XYq‐ /46,XY.
Prenatal diagnosis of cystinosis utilizing chorionic villus sampling
Authors: Smith M. L. , Pellett O. L. , Cass M. M. J. , Kennaway N. G. , Buist N. R. M. , Buckmaster J. , Golbus M. , Spear G. S. , Schneider J. A. 
Published: March 2007

AbstractThe prenatal diagnosis of cystinosis is currently based on the increased amount of free‐cystine present in amniotic fluid cells. Amniocyte cultures must be grown for at least 2 weeks to obtain sufficient cells for such measurements. Thus, the diagnosis cannot be made until close to 20 weeks gestational age by this method. We report a case in which chorionic villi were used for direct cystine measurement resulting in the in utero diagnosis of cystinosis at 9 weeks gestational age. The diagnosis was confirmed by the study of cultured chorionic villus cells, and of the 10‐week abortus.
Expression of transcobalamin II by amniocytes
Authors: Rosenblatt David S. , Hosack Angela , Matiaszuk Nora 
Published: March 2007

AbstractChildren with a genetic absence of transcobalarnin 2 (TC2) are clinically asymptomatic at birth but develop severe megaloblastic anemia early in life. We have examined the incorporation of [57Co]‐CN‐B12 in the absence of any exogenous source of TC2 in control amniotic fluid derived cells and cultured diploid fibroblasts, and in fibroblasts from a patient with TC2 deficiency. Both control fibroblasts and arnniocytes incorporated labelled B12, into TC2‐B12, and the proportion of labelled TC2‐B12 could be increased by growing cells in the presence of chloroquine which prevents intralysosomal hydrolysis of the TC2‐B12 complex. In contrast, fibroblasts from the patient with TC2 deficiency incorporated almost no label as TC2‐B12. These studies suggest that TC2 deficiency either due to aberrant production of TC2 or because of the production of an abnormal TC2 which does not bind B12 can be diagnosed before birth.
Continuous subcutaneous insulin infusion (CSII) in pregnant diabetic patients
Authors: Caruso A. , Lanzone A. , Bianchi V. , Massidda M. , Castelli M. P. , Fulghesu A. M. , Mancuso S. 
Published: March 2007

AbstractThe efficacy of the insulin infusion pump (CSII) in pregnancy was examined in 12 diabetic patients and compared with intermittent insulin therapy (IIT). In patients poorly controlled on IIT constant and rapid equilibrium was achieved with CSII (mean of glucose levels: CSII versus IIT=84 versus 137 mg/dl; S.D. = 36 versus 63 mg/dl; mean amplitude of glycemic excursion (MAGE)=65 versus 112 mg/dl. In patients well controlled on IIT, CSII led to a reduction in the variation of glucose excursions (S.D.= 29 versus 36 mg/dl; MAGE=48 versus 76 mg/dl). CSII generally produced a reduction of 20–37 per cent of daily insulin dose (in three cases there was an increase of dose with the achievement of glycemic control). Furthermore in CSII treated‐patients amniotic glucose, insulin and C‐peptide concentrations werefound tobeinthenormalrange(22.1±10.1 mg/dl; 5.2±2.7μ/ml; 1.25±0.71 ng/ml, respectively). All infants were horn at or near‐term, had no macrosomia or neonatal problems. It is concluded that CSII is a highly efficient way to achieve normal glucose levels in pregnancy, not only in type I, hut also in type II or gestational diabetes.
First trimester diagnosis of cystinosis using intact chorionic villi
Authors: Patrick A. D. , Young E. P. , Mossman J. , Warren R. , Kearney L. , Rodeck C. H. 
Published: March 2007

AbstractCystinosis was diagnosed in the first trimester of pregnancy by studies of uptake and retention of [35S]‐cystine by intact biopsy samples of chorionic villi. The diagnosis was confirmed by similar studies on cell cultures of villi and fetal skin fibroblasts.
Marker chromosomes in A series of 10000 prenatal diagnoses. Cytogenetic and follow‐up studies
Authors: Sachs E. S. , Van Hemel J. O. , Den Hollander J. C. , Jahoda M. G. J. 
Published: March 2007

AbstractIn a series of 10 000 prenatal diagnoses 15 marker chromosomes were detected in our centre. Six of these were familial whilst nine had originated de novo. They were analysed with various staining methods. DA‐DAPI staining was positive in nine out of 12 pregnancies. Six pregnancies were continued. Five normal children were born, one ended in intrauterine fetal death of a normal fetus at 37 weeks. Nine pregnancies were terminated, showing six normal fetuses, one familial cat‐eye syndrome, one fetus with Down syndrome caused by additional trisomy 21 and one fetus with cystic kidneys resp. It is concluded that it seems safe to continue the pregnancy in cases of a familial marker, identical to that of one parent, whilst a de novo DA‐DAPI positive marker seems to present a low risk for fetal anomalies.
Lack of sampling site variation in chorion villus biopsy as assessed by DNA, enzymatic, morphological and cytogenetical analyses
Authors: Upadhyaya Meena , Jasani Bharat , Little Elizabeth , Harper Peter S. , Rees Derek , Roberts Adrian 
Published: March 2007

AbstractA study of villus samples from eight random sites on five electively aborted chorion sacs was performed to determine any significant differences in yield, quality and composition of DNA, iduronate sulphate sulphatase activity and karyoptype status. The villi were also examined for their histological characteristics (e.g. stem, intermediate or terminal villi) and for HCG and BGP immuno‐reactivities. The overall findings indicated no significant site to site variations in any of the parameters studied. It is therefore proposed that any villus should be equally suitable for prenatal diagnosis.
Chorionic villus sampling: An analysis of the obstetric experience of 1000 cases
Authors: Brambati Bruno , Oldrini Angelo , Ferrazzi Enrico , Lanzani Alessandro 
Published: March 2007

AbstractChorionic villus sampling was performed between 7 and 12 weeks gestation in 1000 patients, 935 of whom intended to continue after fetal diagnosis. Transcervical and Transabdominal aspiration techniques were used providing a sampling success rate of 99 per cent. Anatomical and clinical contraindications to transcervical aspiration were pointed out, and the complementary role of the transabdominal approach evaluated.In the 615 concluded pregnancies an overall abortion rate of 4.1 per cent was observed. A significant association between fetal loss and number of catheter insertions was demonstrated. Bacterial inoculation by catheter insertion and colonization of uterine cavity was suspected as the cause of chorionamnionitis diagnosed in two cases (0.2 per cent) after CVS. Bleeding was the most frequent early complication (12.0 per cent) following chorionic aspiration, but was not significantly related to pregnancy wastage. Late complications, i.e. premature rupture of membranes (0.8 per cent), preterm delivery (6.3 per cent), perinatal losses (1.2 per cent), placental disorders (1.6 per cent), and congenital defects (2.6 per cent) did not exceed the expected values. Normal intrauterine growth patterns were ultrasonically estimated by cross‐sectional and longitudinal studies, while the weight at birth was normally distributed in the range of the general population.
Prenatal diagnosis of β thalassaemia by reverse phase HPLC
Authors: Rouyer‐Fessard Ph. , Beuzard Y. , Vidaud M. , John P. , Mibashan R. S. 
Published: March 2007

AbstractReverse phase HPLC of radioactive globin chains has been compared to classical carboxy methyl cellulose chromatography for the prenatal diagnosis of β thalassaemia. The two methods correlated highly (r = 0.97 p < 0.0005) and provided an identical diagnosis for 40 fetal blood samples of fetuses homozygous or heterozygous for β thalassaemia. The HPLC procedure was much faster and required fewer biochemical steps (no globin preparation). It was at least as accurate and more sensitive than the classical chromatography. A single column can be used for 150 analyses and is always ready to be used. Last but not least it is much less expensive than CMC chromatography.