Search Results - (Author, Cooperation:A. Alix)

2013-03-08

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Arabidopsis/*genetics ; DNA Methylation/genetics ; DNA Transposable Elements/genetics ; Epigenesis, Genetic/*genetics ; Epigenomics ; Genetic Variation/*genetics ; Genome, Plant/*genetics ; Linkage Disequilibrium/genetics ; Pollen/genetics ; Polymorphism, Genetic/genetics ; Quantitative Trait Loci ; RNA, Messenger/analysis/genetics ; RNA, Plant/genetics ; Seeds/genetics

1749-6632

Blackwell Publishing Journal Backfiles 1879-2005

Natural Sciences in General

Electronic Resource

0022-2860

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Physics

Electronic Resource

1432-1076

Meconium-stained amniotic fluid ; Catcholamine levels ; Norepinephrine ; Epinephrine ; Tern infants

Springer Online Journal Archives 1860-2000

Medicine

Abstract Catecholamine levels and associated cardiovascular responses were determined in 21 control and 30 term infants with meconium-stained amniotic fluid (MSAF). Cord arterial blood was obtained for determination for norepinephrine (NE) and epinephrine (EPI) levels; cardiovascular measurements included heart rate and systolic blood pressure at 30 min. Pregnancy was uncomplicated in all cases. The total length of labor 964±402 versus 555±312 min (P〈0.001) and active phase of labor 300±261 versus 135±104 min (P〈0.001) were significantly longer in MSAF infants when compared to controls. The 1 min Apgar score was 〈7 (range 1–6) in 11 of 30 MSAF infants versus 0 of 21 control infants; these 11 infants required positive pressure ventilation for approximately 60 s secondary to transient respiratory depression (RD). The 5 min Apgar score was 〉7 in 49 of the 51 infants. Infants with MSAF exhibited a higherP aCO2 (6.89±1.17 vs 6.24±1.17 mm Hg;P〈0.02) and lower pH (7.25±0.06 vs 7.29±0.05;P〈0.02) compared to controls. Infants with transient RD demonstrated the most marked arterial blood gas differences, i.e.,PCO2 7.41±1.30 mm Hg (P〈0.001), pH 7.21±0.07 (P〈0.001) and base deficit −6±4 versus −3±2.8 (P〈0.001) when compared to controls. NE and EPI levels were significantly higher in MSAF versus control infants, i.e., 12600±3040 versus 3740±1000 pg/ml (SEM) (P〈0.02) and 1550±250 versus 620±130 pg/ml (P〈0.001) respectively. The highest values were observed in infants with transient RD. NE levels were related to base deficit (r=−0.45,P〈0.0001) and the presence of meconium (r=0.26,P〈0.05), while EPI levels were related to pH (r=0.44,P〈0.001) and meconium (r=0.28,P〈0.05). MSAF infants exhibited a higher systolic blood pressure at 30 min, i.e., 59±10 versus 54±8 mm HgP〈0.002 when compared to controls. No differences in heart and respiratory rates were noted. These data indicate that infants delivered in the presence of MSAF exhibit significant elevations in catcholamine levels when compared to control infants, which may reflect an adaptive respone to in utero stress.

Electronic Resource

1432-1076

Key words Dexamethasone ; Chronic lung disease ; Neonate ; Cerebral blood flow ; Ocular blood flow

Springer Online Journal Archives 1860-2000

Medicine

Abstract Although dexamethasone (DEX) is used widely in neonates with chronic, and even recently with acute respiratory disease, its potential side-effects on human cerebral and ocular haemodynamics remain unknown. The effects of DEX on cerebral and ocular blood flow velocities were assessed in preterm infants with lung disease and mechanical ventilation. Ten ventilated preterm infants received DEX (0.25 mg/kg/12 h) for ongoing chronic lung disease or extubation failure. Colour Doppler flow imaging studies of the internal carotid, anterior cerebral and ophthalmic arteries were made before and 10, 30, 60, 120 and 240 min after the 1st, 3rd, and 5th doses of DEX. Peak systolic, temporal mean, and end-diastolic flow velocities and the resistence index (RI) of Pourcelot were determined. The brain was examined by ultrasonography before and at the end of each Doppler study. All patients were continuously monitored for transcutaneous blood gases and blood pressure. All flow velocities and the RI of the internal carotid, anterior cerebral and ophthalmic arteries showed a similar trend throughout the study. The means of the values averaged for the 240 min of cerebral and ocular blood flow velocity with each dose were progressively higher and the values of the RI progressively lower up to the 5th dose. The most significant changes occurred in end-diastolic flow velocity and consisted of a percentage increase between the 1st and 5th dose of 72% in the internal carotid artery, 102% in the anterior cerebral artery and 84% in the ophthalmic artery. Changes in arterial blood pressure followed a pattern similar to that of changes in blood flow velocity. Conclusions Dexamethasone increments cerebral and ocular blood flow velocity. We speculate that this finding may be relevant to the development of brain and retinal injury.

Electronic Resource

1432-1017

Tropoelastin ; Predictive methods ; Secondary structure ; Antigenic index ; Epitope

Springer Online Journal Archives 1860-2000

Biology

Physics

Abstract Secondary structure and antigenicity predictive methods have been applied to the sequences of human and bovine tropoelastins in order to have some insight into the molecular structure of its insoluble counterpart, i.e., elastin. For both tropoelastins, all the predictions yielded 11 major regions, in which the pleated conformation was predominant, separated by 10 strong helical segments of various lengths located within alanyl rich regions of the chains. The overall conformations of human and bovine tropoelastins were estimated to contain 18 ± 5% α-helices, 63 ± 17% β-sheets, 13 ± 13% β-turns and 6 ± 6% random coil. For both tropoelastins, antigenicity predictions indicated the presence of seven synthetic decapeptides corresponding to continuous linear epitopes of the molecule. Some of the predicted epitopes are located in the same regions in both species while others are not. These predictions have allowed us to propose an α/β conformation for tropoelastin. Therefore this extracellular matrix macromolecule might be more structured (10 helical segments for about 18% of the overall structure) than previously suggested.

Electronic Resource

1432-1076

Key words Beta2-microglobulin ; Neonatal meningitis ; TORCH ; infections ; Central nervous system

Springer Online Journal Archives 1860-2000

Medicine

Abstract Beta2-microglobulin (β2m) determination in CSF of 72 neonates who underwent a spinal tap as part of a sepsis or meningo-encephalitis workup was performed to evaluate the usefulness of this test in the diagnosis of CNS infections. β2m was measured by enzyme immunoassay. Sixty neonates had sterile culture and normal neurological status at discharge. Twelve infants had CNS infections: 8 bacterial meningitis, 3 TORCH infections (T = toxoplasmosis, O = others, R = rubella, C = cytomegalovirus and H=herpes simplex) and 1 viral meningitis. Neonates with CNS infection exhibited significantly higher CSF β2m levels compared to neonates with sterile culture (6.24 ± 2.66 vs 1.74 ± 0.5 mg/l; P 〈 0.0001). CSF β2m levels did not correlate with the white cell count, total protein concentration or glucose level in CSF. When serum and CSF levels were measured simultaneously, the CSF β2m level was significantly higher than the corresponding serum level in patients with CNS infection (6.98 ± 2.5 vs 3.2 ± 0.25 mg/l; P 〈 0.01). Sensitivity, specificity, and predictive values were estimated for different cut-off points. The best operational diagnostic cut-off value was 2.25 mg/l. Receiver operating characteristic curve analysis showed an appropriate trade-off between specificity and sensitivity and indicated that CSF β2m was accurate in distinguishing between neonates with and without CNS infection. Conclusion CSF β2m may be a useful ancillary tool in neonates when CNS infection is suspected.

Electronic Resource

0377-0486

Chemistry ; Analytical Chemistry and Spectroscopy

Wiley InterScience Backfile Collection 1832-2000

Chemistry and Pharmacology

Physics

A simple method for determining the quantitative secondary structure of proteins from their Raman spectra, the reference intensity profiles method, is proposed. This uses as a model the Raman spectral intensities of the backbone amide I vibrations (range 1630-1700 cm-1), corresponding to pure classes of secondary conformations, i.e. α-helical, β-sheet and undefined structures. The reference intensity profiles were computed by a step-by-step fit of the experimental amide I spectra of a large number of proteins, the secondary structures of which were well known from x-ray diffraction data in the solid state. The method could be of use in determining the secondary structure of a protein in any state. In the case of a protein in solution, the method solves simultaneously for the secondary structural contents and the subtraction coefficient, thus determining the solvent spectral contribution. The proposed method has been applied with success to a large set of proteins. The correlation coefficient between x-ray data and the Raman calculated results is close to 0.97 for each class of structure, so accurate estimates of secondary structure may be derived by using the reference intensity profiles method.

4 Ill.

Electronic Resource

0377-0486

Chemistry ; Analytical Chemistry and Spectroscopy

Wiley InterScience Backfile Collection 1832-2000

Chemistry and Pharmacology

Physics

The Raman spectra of the platinum complex [Pt(NH3)4]Cl2 and [Pt(ND3)4]Cl2 in the solid state and in aqueous solution and of [Pt(NH3)4]Cl2·H2O in the solid state have been obtained and discussed. All the ligand vibrations in the deformation and rocking regions have been studied and some show interesting changes on hydration. The polarization data and high quality spectra obtained in this study allow a more complete assignment of the vibrational modes of the complex.

2 Ill.

Electronic Resource