bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, characterization, and utilization of itaconate‐based polymerizable surfactants for the preparation of surface‐carboxylated polystyrene latexes
Authors: Prasath R. Arun , Ramakrishnan S. 
Published: June 2005

AbstractTwo polymerizable surfactants (surfmers), namely, monododecyl itaconate (MDDI) and monocetyl itaconate (MCI), were synthesized by reacting itaconic anhydride with 1‐dodecanol and cetyl alcohol, respectively. A series of uncrosslinked and crosslinked surface‐carboxylated latexes were prepared from styrene and styrene–divinylbenzene, respectively, using varying amounts of these two surfmers. The latexes were characterized by gravimetry, dynamic light scattering, and conductometric titration in order to obtain the conversion, particle size distribution, and concentration of surface carboxyl groups, respectively. The size of latex varied between 41–72 nm and was seen to depend inversely on the surfmer concentration. In the case of the soluble polystyrene latexes, solution 1H NMR spectra provided conclusive evidence for surfmer incorporation into the polymer chain. Comparison of the incorporation levels determined by NMR with the surface carboxylic acid concentrations in the latexes, determined by conductometric titrations, revealed that the majority of the surfmers, as ancticipated, were present on the latex surface. The study of the stability of the latexes to varying salt concentrations clearly demonstrated that the smaller‐size latexes having higher surface carboxyl group density exhibited far improved stability when compared with the larger‐size ones having lower surface carboxyl group density. Similarly, enhanced freeze‐thaw stability was also observed for the smaller‐size latexes. MCI‐based latexes exhibited marginally improved stability compared with those prepared using MDDI, which again seems to be because of the higher surface functional group density in the former. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3257–3267, 2005
Copolymerization of ε‐caprolactone and glycolide—A comparison of bismuth(III) hexanoate and tin(II) octanoate as initiators
Authors: Kricheldorf Hans R. , Hachmann‐Thiessen Heiko 
Published: June 2005

Abstractε‐Caprolactone and glycolide were copolymerized in bulk either with tin(II) 2‐ethylhexanoate (SnOct2) or with bismuth(III) n‐hexanoate (BiHex3) as initiators and with tetra(ethylene glycol) as a coinitiator. The temperature was varied from 100 to 160 °C. The sequences were characterized with 1H and 13C NMR spectroscopy. Surprisingly, it was found that higher temperatures favored the formation of alternating sequences. Furthermore, the content of alternating dyads was significantly higher when BiHex3 was used instead of SnOct2. An increase in reaction time caused partial randomization of the sequences regardless of the initiator. Size exclusion chromatography measurements in chloroform yielded number‐average molecular weights in agreement with the feed ratios. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3268–3277, 2005
Molecular dynamics study of water penetration in staphylococcal nuclease
Authors: Damjanović Ana , García‐Moreno Bertrand , Lattman Eaton E. , García Angel E. 
Published: June 2005

AbstractThe ionization properties of Lys and Glu residues buried in the hydrophobic core of staphylococcal nuclease (SN) suggest that the interior of this protein behaves as a highly polarizable medium with an apparent dielectric constant near 10. This has been rationalized previously in terms of localized conformational relaxation concomitant with the ionization of the internal residue, and with contributions by internal water molecules. Paradoxically, the crystal structure of the SN V66E variant shows internal water molecules and the structure of the V66K variant does not. To assess the structural and dynamical character of interior water molecules in SN, a series of 10‐ns‐long molecular dynamics (MD) simulations was performed with wild‐type SN, and with the V66E and V66K variants with Glu66 and Lys66 in the neutral form. Internal water molecules were identified based on their coordination state and characterized in terms of their residence times, average location, dipole moment fluctuations, hydrogen bonding interactions, and interaction energies. The locations of the water molecules that have residence times of several nanoseconds and display small mean‐square displacements agree well with the locations of crystallographically observed water molecules. Additional, relatively disordered water molecules that are not observed crystallographically were found in internal hydrophobic locations. All of the interior water molecules that were analyzed in detail displayed a distribution of interaction energies with higher mean value and narrower width than a bulk water molecule. This underscores the importance of protein dynamics for hydration of the protein interior. Further analysis of the MD trajectories revealed that the fluctuations in the protein structure (especially the loop elements) can strongly influence protein hydration by changing the patterns or strengths of hydrogen bonding interactions between water molecules and the protein. To investigate the dynamical response of the protein to burial of charged groups in the protein interior, MD simulations were performed with Glu66 and Lys66 in the charged state. Overall, the MD simulations suggest that a conformational change rather than internal water molecules is the dominant determinant of the high apparent polarizability of the protein interior. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Computation of quantum mechanical hybridization and dipole correlation of the electronic structure of the F3B–NH3supermolecule
Authors: Ghosh Dulal C. , Bhattacharyya Soma 
Published: June 2005

AbstractA valence bond description of the electronic structure and the process of the formation of the adduct supermolecule, F3B–NH3by charge transfer interactions between a Lewis acid, BF3, and a Lewis base, NH3, is computed in terms of the quantum mechanical localized molecular orbital (LMO) method. A dipole correlation of electronic structure is also reported. The valence bond description in terms of bond pair and lone pair is transparent in the generated LMOs of the donor, acceptor, and adduct supermolecule. It is transparent in the computed LMOs that the lone pair of N in NH3is actually involved in forming a new dative bond between B and N atoms. The present work reports the evaluated hybridization status of the boron, nitrogen, and fluorine atoms in the interesting donor–acceptor compound, F3B–NH3. It is transparent in the computed results that the quantum mechanical hybridization automatically incorporates the effect of change of environment in the pattern of hybridization perfectly in accordance with Bent's rule. The calculated dipole moment of the supermolecule is high; it is partitioned into contributions resulting from bond moments and atomic dipoles, as contributions from hybrid orbitals accommodating lone pairs of electrons. The magnitude of atomic dipole is small compared with the bond dipole component. A rationale of the bond moment of the molecule is attempted in terms of the charge density distribution on atomic sites and the atomic dipole is correlated in terms of the pattern of hybridization of lone pairs on the F atoms. The generated LMOs reveal that only one lone pair on each F atom is in a hybrid orbital, and the remaining two lone pairs are in pureporbitals. The small lone pair contribution to molecular dipole is thus transparent in computed quantum mechanical hybridization that shows that, out of three, only one lone pair on the F atoms can set in atomic dipole. This study demonstrates that atomic dipole can be used as a descriptor of the hybridization status of lone pairs on atoms in the molecules. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
The first and second derivative matrices in the random phase approximation scheme by using the Lagrangian technique
Authors: Gotoh Masashi , Tachikawa Masanori , Ryuo Kotaro , Sasagane Kotoku , Suzuki Kazunari , Mori Kazuhide , Nakamura Shinichiro 
Published: June 2005

AbstractWe have presented the explicit formulas for first and second derivatives of A and B matrices, appearing in the random phase approximation (RPA), with the aid of Lagrangian technique. Owing to the 2n + 1 rule, the Lagrangian approach is more efficient than the conventional approach to evaluate the higher‐order matrix elements. We have confirmed the validity of our formulation by demonstrating the geometry optimization of the first‐excited singlet states of formaldehyde, ethylene, and 1‐amino‐3‐propenal molecules. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Esophageal resection and by‐pass: A 6 year experience with a low postoperative mortality
Authors: Collard Jean ‐Marie , Otte Jean ‐Bernard , Reynaert Marc , Michel Luc , Carlier Marie ‐Anne , Kestens Paul ‐Jacques 
Published: June 2005

AbstractFrom 1984 to 1989, 175 esophageal cancer patients, 10 patients admitted for severe caustic esophagitis, and 1 patient with pyothorax due to iatrogenic perforation of the esophagus underwent an esophageal resection or bypass operation. One hundred sixty‐eight esophageal resections were performed on 167 patients; 13 were total, 106 subtotal and 49 distal. Nineteen digestive transplants were pulled up to the neck to bypass the esophagus or re‐establish continuity after an esophagectomy made elsewhere. Digestive continuity was restored by a long gastric transplant in 120 patients, a colon segment in 17, a jejunal loop in 35, and a short gastric transplant after limited esophago‐gastrectomy in 14 patients. Thirty day mortality was 0 in the whole group. Hospital mortality was 1.2% in the resection group and 10.5% in the bypass group (p=0.048). Nonfatal postoperative complications consisted of respiratory distress in 33 patients, recurrent nerve palsy in 10, anastomotic fistula in 10 (cervical in 8 and intrathoracic in 2) and anastomotic stenosis in 18 patients. Respiratory complications were more frequent in patients with a cancer of the thoracic esophagus (29/111) than in those operated on for a cancer located in the esophago‐gastric junction (4/50) (p<0.01). Anastomotic stenosis occurred more frequently in the neck (17/137) than in the chest (1/49) (p<0.05). Nine patients were reoperated on for a technical complication; intraabdominal hemorrhage (1), thoracic duct injury (2), acute cholecystitis (1), tight stricture of the esophageal anastomosis (2), jejuno‐duodenal anastomotic fistula (2), or stridor related to recurrent nerve palsy (1). Low postoperative mortality may be achieved after esophageal surgery, even in a nonselected Caucasian population. However, nonfatal complications indicate that an esophageal resection or bypass operation remains a major surgical procedure. The surgical principles which we have applied to minimize postoperative mortality and severe complications are presented.
Hereditary variation of liver enzymes involved with detoxification and neurodegenerative disease
Authors: Williams A. C. , Steventon G. B. , Sturman S. , Waring R. H. 
Published: June 2005

SummaryEnzymes involved with the metabolic transformation of xenobiotics have recently been studied in patients with the neurodegenerative diseases, Alzheimer's disease, Parkinson's disease and motor neurone disease. Defects were detected in sulphur pathways and also, in the case of Parkinson's disease, in monoamine oxidase B. The possibility exists that the ability to cope safely with endogenous and exogenous substances which have neurotoxic properties is important in the pathogenesis of these diseases. Potentially such individuals could be identified preclinically and these diseases postponed by reduction in the load of toxin or modification of the relevant enzymic activity.
Interrelationships of liver and brain with special reference to reye syndrome
Authors: Brown J. K. , Imam H. 
Published: June 2005

SummaryReye syndrome is an acute non‐inflammatory encephalopathy that can be precipitated by toxic, infective, metabolic or hypoxic upsets. The biochemical changes point to mitochondrial dysfunction and this is substantiated by structural changes in mitochondria on electron microscopy. The toxic metabolites that accumulate are similar to those incriminated in hepatic encephalopathy and other metabolic diseases. These metabolites exert their deleterious effects by direct neuronal damage, neurotransmitter blockade, vascular damage, cerebral oedema, hypoxic ischaemic damage, demyelination, retardation of brain growth and neuronal storage. Brain capillary endothelial cells are very rich in mitochondria and mitochondrial disorders can effect the central nervous system primarily, and not just as a consequence of systemic metabolic upset.
Techniques for studying hepatic metabolismin vivo
Authors: Leonard J. V. , Thompson G. N. 
Published: June 2005

SummaryTechniques for studying metabolic eventsin vivo in patients with inborn errors are reviewed. Loading or provocation tests that have been used widely are insensitive and frequently non‐specific. Compounds labelled with stable isotopes can be used to study enzyme kinetics and substrate turnover, providing more detailed and specific information. Intracellular events may be studied using nuclear magnetic resonance spectroscopy.The results using these techniques to study patients with selected inborn errors are discussed, namely phenylketonuria, glycogen storage disease type I and propionic acidaemia.
Tyrosinaemia type I — an update
Authors: Kvittingen E. A. 
Published: June 2005

SummaryTyrosinaemia type I is a recessively inherited disorder caused by a deficiency of fumarylacetoacetase (FAH), the last enzyme in tyrosine degradation. The presumed toxic agents are fumaryl‐ and maleylacetoacetate which are converted to succinylacetone (SA), a metabolite found in increased amounts in urine and plasma of the patients. The major clinical features are progressive liver damage and renal tubular defects with hypophosphataemic rickets. Renal tubular dysfunctions with secondary rickets may be lacking altogether, even in chronic patients. Hepatocellular carcinoma is a major cause of death in the chronic form. Diagnosis of the disorder is made by assay of SA in urine and serum and by determination of FAH in lymphocytes or fibroblasts. Prenatal diagnosis is performed by SA assay in amniotic fluid supernatant and FAH analysis in cultured amniotic fluid cells or chorionic villus material. Presence of a ‘pseudodeficiency’ gene for FAH prevents prenatal diagnosis by enzyme analysis in some families, and this gene also precludes identification of heterozygotes outside tyrosinaemia families. Immunoblot analyses show that acute patients and some chronic patients lack immunoreactive FAH protein. cDNA probes for FAH have been developed and several polymorphisms related to the FAH gene have been reported, which may allow prenatal diagnosis in families with complex genotypes. The gene for FAH has been mapped to chromosome 15 q23–q25. Liver transplantation is the ultimate treatment; most patients continue to excrete SA in urine after liver transplantation and therefore there is a possibility of kidney disease after transplantation.
Investigation of the molecular basis of the genetic deficiency of UDP‐glucuronosyl‐transferase in Crigler‐Najjar syndrome
Authors: Robertson K. J. , Clarke D. , Sutherland L. , Wooster R. , Coughtrie M. W. H. , Burchell B. 
Published: June 2005

SummaryLiver biopsy samples were obtained from eight Crigler‐Najjar patients. Bilirubin UDPGT activity, assayed by a microassay with HPLC analysis, was not detectable in type I livers, and low levels (9–26% of controls) of monoglucuronide conjugates only were observed in type II livers. 1‐Naphthol UDPGT activity was normal in most patients, where membrane integrity was maintained by correct sample procurement and preparation. Our data on type II livers suggest that a defect in UDPGA transport is an unlikely cause of the hyperbilirubinaemia, but reduced affinity for UDPGA was observed in one sample. Analysis of four patient liver samples by immunoblot analysis revealed the heterogeneous nature of this inherited disease within the patient population, and one sample where 1‐naphthol UDPGT activity was considerably reduced appeared to correlate with the non‐detection of a phenol UDPGT protein. Progress towards a molecular genetic diagnosis of Crigler‐Najjar syndromes is discussed.
Treatment of inherited metabolic disorders by liver transplantation
Authors: Burdelski M. , Rodeck B. , Latta A. , Latta K. , Brodehl J. , Ringe B. , Pichlmayr R. 
Published: June 2005

SummaryAmong the worldwide accepted indications for liver transplantation, inherited metabolic disorders play an increasing role. In some paediatric centres this indication runs second after extrahepatic biliary atresia.The aim of liver transplantation in inherited metabolic disorders is twofold: the first is to save a patient's life, the second is to accomplish phenotypic and functional cure of his disease. These aims may be achieved in disorders presenting with cirrhosis, hepatoma, life‐threatening progression or failure of other organs with preserved liver function. The timing of liver transplantation has become easier with development of surgical techniques of reduced‐size donor livers. These techniques enable the performance of liver transplantation with ABO blood group compatible organs of almost any size if indicated either by deterioration of liver function or impending complications such as hepatoma or life‐threatening progression. In comparison with other indications such as extrahepatic biliary atresia, postnecrotic liver cirrhosis or acute liver failure, the results of transplantation in patients with inherited metabolic disorders seem to be better, reaching up to 78–95% actuarial 1‐year survival rates. However, lifelong immunosuppressive therapy is necessary. This seems to be acceptable even in disorders with only partial liver function defects.
The place of fetal liver transplantation in the treatment of inborn errors of metabolism
Authors: Touraine J. ‐L. , Laplace S. , Rezzoug F. , Sanhadji K. , Veyron P. , Royo C. , Maire I. , Zabot M. T. , Vanier M. T. , Rolland M. O. , Goillot E. , de Bouteiller O. , Garnier J. L. , Pouteil‐Noble C. , Raffaele P. , Livrozet J. M. , Saint‐Marc T. 
Published: June 2005

SummaryOver the last 16 years, 202 fetal tissue transplants have been performed in our department to treat 29 patients with severe inborn errors of metabolism without immunodeficiency, 26 patients with congenital and severe immunodeficiency diseases, and 2 patients with severe aplastic anaemia. The actuarial survival curve of patients with inborn errors of metabolism treated with fetal liver transplantation shows a 12‐year survival of 77%. The condition of many of these patients has been improved by the treatment, but transplantation has had to be repeated in order to maintain clinical amelioration. Enzyme levels were not significantly and durably increased in peripheral blood but the quantities of substrates detected in sera and urines were significantly reduced and tissue deposits were stabilized.
I‐cell disease
Authors: Patel Z. M. , Ambani L. M. 
Published: June 2005

AbstractA 6‐month‐old female infant presented with severe psychomotor retardation, coarse facies, gingival hyperplasia, thick skin, restricted joint movements and radiological features suggestive of the Hurler syndrome. Her urine showed no excess excretion of mucopolysaccharides. I‐cell disease was suspected from the onset of clinical features in early infancy, the subsequent progress and the absence of mucopolysacchariduria. Marked elevation of the activity in serum of three lysosomal enzymes confirmed the diagnosis. This patient had repeated convulsions, a feature not previously reported in this condition. This is the first case report of I‐cell disease from India.
Skeletal muscle of patients with gyrate atrophy of the choroid and retina and hyperornithinaemia in ultralow‐field magnetic resonance imaging and computed tomography
Authors: Valtonen M. , Näntö‐Salonen K. , Heinänen K. , Alanen A. , Kalimo H. , Simell O. 
Published: June 2005

SummaryGyrate atrophy of the choroid and retina with hyperornithinaemia (GA), an autosomal recessive disease, affects skeletal muscle in addition to the eye. Muscle biopsy samples show prominent type 2 muscle fibre atrophy. Atrophic fibres also contain accumulations of tubular aggregates in electron microscopy. To evaluate skeletal muscle involvement in detail, the thigh muscles of 7 patients with GA were examined using semi‐open conchotome muscle biopsies, computed tomography (CT) and ultralow‐field magnetic resonance imaging (MRI) at 0.02 T. In MRI, the T1 and T2 proton relaxation times were measured. Type 2 muscle fibre atrophy was found in all biopsy samples (100%) and tubular aggregates in 6 of the 7 samples studied (87%). The CT density of the muscle tissue was increased in the only child of the study, decreased in 3 elderly subjects, and normal in the remaining 3 patients. Mean T1 relaxation times of the patients were decreased (135±5 ms) as compared to those of 6 healthy controls (157±12 ms) (p=0.002). The T2 relaxation time was slightly increased (40±3 ms) as compared to the controls (35±7 ms; not significant,p=0.3). Our findings suggest that the thigh muscles of the patients with GA universally show changes in CT and MRI studies, but relaxation time measurements gave little additional information on the muscle metabolism.
Rapid identification of PKU‐associated mutations by multiplex DGGE analysis of the PAH gene
Authors: Michiels L. , François B. , Raus J. , Vandevyver C. 
Published: June 2005

SummaryA system of five sets of multiplex polymerase chain reaction amplifications followed by denaturing gel electrophoresis analysis allows rapid analysis of all 13 exons of the phenylalanine hydroxylase gene.
Late‐onset holocarboxylase synthetase deficiency
Authors: Gibson K. M. , Bennett M. J. , Nyhan W. L. , Mize C. E. 
Published: June 2005

SummaryWe report a 21‐month‐old female patient whose urine organic acid profile suggested a biotin utilization abnormality consistent with multiple carboxylase deficiency. For most previously reported patients, holocarboxylase synthetase deficiency has correlated with the early‐onset variant of multiple carboxylase deficiency; conversely, biotinidase deficiency has been characteristic of the late‐onset form.In vitro enzyme studies revealed that our patient suffered from holocarboxylase synthetase deficiency. We suggest that holocarboxylase synthetase deficiency should be considered in the differential diagnosis of older patients in whom there is suspicion of a defect in biotin metabolism.
Complementation analysis of systemic cytochrome oxidase deficiency presenting as Leigh syndrome
Authors: Brown R. M. , Brown G. K. 
Published: June 2005

SummarySystemic cytochrome oxidase deficiency presenting as Leigh syndrome is a well‐defined biochemical entity. Although the enzyme defect is demonstrable in all tissues, clinical abnormalities are restricted to the central nervous system. Biochemical studies comparing rates of synthesis of cytochrome oxidase subunits with the steady‐state levels of immunoreactive protein in the mitochondrial inner membrane suggest a defect in assembly or stability of the complex. Family studies suggest that the disease is inherited as an autosomal recessive and somatic cell genetic studies directly implicate nuclear genes. As there are likely to be a number of different nuclear genes involved in the synthesis, assembly and stability of the cytochrome oxidase complex, we have fused patient fibroblasts and analysed the heterokaryons for complementation of the enzyme defect in an attempt to define the extent of genetic heterogeneity in this condition. So far, three complementation groups have been defined, although the majority of patients fall into a single group.