bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low mutant load of mitochondrial DNA G13513A mutation can cause Leigh's disease
Authors: Kirby Denise M. , Boneh Avihu , Chow C. W. , Ohtake Akira , Ryan Michael T. , Thyagarajan Dominic , Thorburn David R. 
Published: September 2003

AbstractRespiratory chain complex I deficiency is a common cause of Leigh's disease (LD) and can be caused by mutations in genes encoded by either nuclear or mitochondrial DNA (mtDNA). Most pathogenic mtDNA mutations act recessively and only cause disease when present at high mutant loads (typically >90%) in tissues such as muscle and brain. Two mitochondrial DNA mutations in complex I subunit genes, G14459A in ND6, and T12706C in ND5, have been associated with complex I deficiency and LD. We report another ND5 mutation, G13513A, in three unrelated patients with complex I deficiency and LD. The G13513A mutation was present at mutant loads of approximately 50% or less in all tissues tested, including multiple brain regions. The threshold mutant load for causing a complex I defect in cultured cells was approximately 30%. Blue Native polyacrylamide gel electrophoresis showed that fibroblasts with 45% G13513A mutant load had approximately 50% of the normal amount of fully assembled complex I. Fibroblasts with greater than 97% of the ND6 G14459A mutation had only 20% fully assembled complex I, suggesting that both mutations disrupt complex I assembly or turnover. We conclude that the G13513A mutation causes a complex I defect when present at unusually low mutant load and may act dominantly.
Predictors of neuropathological severity in 100 patients with Huntington's disease
Authors: Rosenblatt Adam , Abbott Margaret H. , Gourley Lisa M. , Troncoso Juan C. , Margolis Russell L. , Brandt Jason , Ross Christopher A. 
Published: September 2003

AbstractSubjects were followed in the Longitudinal Core Study of the Baltimore Huntington's Disease Center and given annual neurological, cognitive, and psychiatric examinations. Postmortem neuropathological grade was assigned using the system of Vonsattel and colleagues. We examined the correlations between the neuropathological grade and scores on the Quantified Neurological Examination (QNE) and its chorea and motor impairment subscales, the Mini‐Mental State Examination (MMSE), the HD Activities of Daily Living (ADL) Scale, and a number of demographic variables (CAG number, age of onset, age at death, disease duration) in 100 subjects who had been examined within 1,000 days of death. All measures showed significant correlation with Vonsattel score except for chorea. The strongest effect was that of motor impairment score (r2 = 0.351, p < 0.0001). In a stepwise correlation of clinical variables, motor impairment remained significant. The largest effect for a demographic variable was for age of onset (r2 = 0.226, p < 0.0001) A partial correlation was significant between CAG number and Vonsattel grade, controlling for age at death or disease duration. Motor impairment appears to be a good clinical measure of neuronal cell loss, at least late in the course of HD and therefore may prove useful in observational and treatment studies.
Myosin storage myopathy associated with a heterozygous missense mutation in MYH7
Authors: Tajsharghi Homa , Thornell Lars‐Eric , Lindberg Christopher , Lindvall Björn , Henriksson Karl‐Gösta , Oldfors Anders 
Published: September 2003

AbstractMyosin constitutes the major part of the thick filaments in the contractile apparatus of striated muscle. MYH7 encodes the slow/β‐cardiac myosin heavy chain (MyHC), which is the main MyHC isoform in slow, oxidative, type 1 muscle fibers of skeletal muscle. It is also the major MyHC isoform of cardiac ventricles. Numerous missense mutations in the globular head of slow/β‐cardiac MyHC are associated with familial hypertrophic cardiomyopathy. We identified a missense mutation, Arg1845Trp, in the rod region of slow/β‐cardiac MyHC in patients with a skeletal myopathy from two different families. The myopathy was characterized by muscle weakness and wasting with onset in childhood and slow progression, but no overt cardiomyopathy. Slow, oxidative, type 1 muscle fibers showed large inclusions consisting of slow/β‐cardiac MyHC. The features were similar to a previously described entity: hyaline body myopathy. Our findings indicate that the mutated residue of slow/β‐cardiac MyHC is essential for the assembly of thick filaments in skeletal muscle. We propose the term myosin storage myopathy for this disease.
Familial aggregation of early‐ and late‐onset Parkinson's disease
Authors: Marder Karen , Levy Gilberto , Louis Elan D. , Mejia‐Santana Helen , Cote Lucien , Andrews Howard , Harris Juliette , Waters Cheryl , Ford Blair , Frucht Steven , Fahn Stanley , Ottman Ruth 
Published: September 2003

AbstractThe role of heredity in early‐ versus late‐onset Parkinson's disease (PD) is controversial. We estimated the degree of increased risk of PD in first‐degree relatives of 221 PD probands with age of onset 50 years or younger and 266 PD probands with age of onset older than 50 years compared with the first‐degree relatives of 409 control probands. Risk of PD was similar among first‐degree relatives of early‐onset PD probands (risk ratio [RR], 2.9; 95% confidence interval [CI], 1.6–5.0; p = 0.0002) and late‐onset PD probands (RR, 2.7; 95% CI, 1.6–4.4; p = 0.0002) when each was compared with first‐degree relatives of controls. However, siblings of early‐onset PD probands were at markedly increased risk of PD compared with siblings of controls (RR, 7.9; 95% CI, 2.5–25.5; p = 0.0005), whereas parents of early‐onset PD probands were not at significantly increased risk compared with parents of controls (RR, 1.7; 95% CI, 0.9–3.3; p = 0.2). In late‐onset families, both siblings (RR, 3.6; 95% CI, 1.3–10.3; p = 0.02) and parents (RR, 2.5; 95% CI, 1.4–4.6; p = 0.003) were at increased risk compared with control relatives. This pattern is consistent with an autosomal recessive contribution to the inheritance of early but not late‐onset PD. Genetic factors are important in both early‐ and late‐onset PD, but specific genes and mode of inheritance may differ between the two groups. Ann Neurol 2003;54:507–513
Epilepsy in low‐grade gliomas: The impact on cognitive function and quality of life
Authors: Klein Martin , Engelberts Nadine H. J. , van der Ploeg Henk M. , Kasteleijn‐Nolst Trenité Dorotheé G. A. , Aaronson Neil K. , Taphoorn Martin J. B. , Baaijen Hans , Vandertop W. Peter , Muller Martin , Postma Tjeerd J. , Heimans Jan J. 
Published: September 2003

AbstractLow‐grade gliomas frequently are associated with epilepsy. The purpose of this study is to determine the impact of epilepsy and antiepileptic drug (AED) treatment on cognitive functioning and health‐related quality of life (HRQOL) in these patients. One hundred fifty‐six patients without clinical or radiological signs of tumor recurrence for at least 1 year after histological diagnosis and with an epilepsy burden (based on seizure frequency and AED use) ranging from none to severe were compared with healthy controls. The association between epilepsy burden and cognition/HRQOL was also investigated. Eighty‐six percent of the patients had epilepsy and 50% of those using AEDs actually were seizure‐free. Compared with healthy controls, glioma patients had significant reductions in information processing speed, psychomotor function, attentional functioning, verbal and working memory, executive functioning, and HRQOL. The increase in epilepsy burden that was associated with significant reductions in all cognitive domains except for attentional and memory functioning could primarily be attributed to the use of AEDs, whereas the decline in HRQOL could be ascribed to the lack of complete seizure control. In conclusion, low‐grade glioma patients suffer from a number of neuropsychological and psychological problems that are aggravated by the severity of epilepsy and by the intensity of the treatment.
Voltage‐gated potassium channel antibodies in limbic encephalitis
Authors: Pozo‐Rosich Patricia , Clover Linda , Saiz Albert , Vincent Angela , Graus Francesc 
Published: September 2003

AbstractWe found voltage‐gated potassium channel (VGKC) antibodies in 4 of 15 patients with limbic encephalitis (LE). Two patients with idiopathic LE had high VGKC antibody levels (>800pM; controls <100pM), that fell in parallel with a clinical response to immunotherapy. Two patients with lower VGKC antibodies (170pM, 300pM) had lung cancer (radiological evidence only in one) and the LE improved with immunotherapy in one. The other 11 patients without VGKC antibodies had paraneoplastic LE and eight onconeural antibodies (Hu in 6; Ma2 in 2). VGKC antibodies do not unambiguously discriminate between idiopathic or paraneoplastic LE but probably indicate a good response to immunotherapy. Ann Neurol 2003;54:530‐533
Neuropathological findings in West Nile virus encephalitis: A case report
Authors: Agamanolis Dimitri P. , Leslie Michael J. , Caveny Elizabeth A. , Guarner Jeannette , Shieh Wun‐Ju , Zaki Sherif R. 
Published: September 2003

AbstractA 67‐year‐old woman had fever, myalgias, progressive weakness, and respiratory insufficiency. In 9 days, flaccid areflexic quadriparesis and bulbar palsy developed. She died 26 days after the onset of her illness. Serum and cerebrospinal fluid serology were positive for West Nile virus. Neuropathological study showed changes consistent with a viral encephalomyelitis, similar to poliomyelitis. The brainstem showed neuronal loss and multiple foci of necrosis. The spinal cord showed severe loss of anterior and posterior horn neurons. Immunohistochemistry identified West Nile virus antigens in the brainstem and spinal cord. Paralysis, in West Nile virus encephalitis, is caused by destruction of motor neurons. Ann Neurol 2003;54:547‐551
Development of polymer‐molding‐releasing metal mold surfaces with perfluorinated‐group‐containing polymer plating
Authors: Mori Kunio , Sasaki Yaeko , Hirahara Hidetoshi , Oishi Yoshiyuki 
Published: September 2003

AbstractThe polymer‐molding‐releasing properties of metal molds were found to be related to the following factors: (1) interfacial chemical bonding between the surfaces of polymers and metal molds and (2) a friction force or friction coefficient between polar substances and/or low‐molecular‐weight components in the polymers and physical factors on mold surfaces. We theoretically and experimentally confirmed that metal molds with good polymer‐molding‐releasing properties had very small surface free energies. We also proved that the surface free energies in the resulting polymer moldings were lower than before shaping. The molding releasing properties improved with decreasing friction force and friction coefficient between the surface of polymers and metal molds and with decreasing surface free energy. To obtain metal molds with lower surface free energies, we developed a polymer plating method with perfluorinated‐group‐containing triazine dithiol. The Metal mold treated by polymer plating had lower critical surface tension (7.5 mJ/m2) than Teflon (18 mJ/m2), indicating that the surface consisted of CF3− groups. The treated mold showed excellent durability in its releasing properties, which was better than that of the untreated mold. This technique was developed for the production of molds for the Fθ lens and the naturally bright focusing screen. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2549–2556, 2003
Effect of reinforcement type and length on physical properties, surface quality, and cycle time for sheet molding compound (SMC) compression molded parts
Authors: Boylan Sarah , Castro Jose M. 
Published: September 2003

AbstractOne of the fastest growing applications of sheet molding compound (SMC) compression molding is the manufacture of truck body panels. The trucking industry requires parts with high strength and stiffness, but the surface quality is also important. In this study, the effect of reinforcement type and length on physical properties, surface quality, and cycle time are evaluated. In particular, the effect of different lengths of carbon fibers and glass fibers with different sizing are studied. It was found that for the same volume percent, carbon fibers greatly improve the stiffness of the SMC at the sacrifice of strength and surface quality and also require larger fill times for the same molding force, as compared to glass fibers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2557–2571, 2003
Proton exchange membranes by grafting of styrene–acrylic acid onto FEP by preirradiation technique. I. Effect of synthesis conditions
Authors: Phadnis Swati , Patri M. , Hande Varsha R. , Deb P. C. 
Published: September 2003

AbstractGrafting of styrene–acrylic acid (sty–AA) polymer onto fluorinated ethylene propylene copolymer (FEP) was carried out by preirradiation of FEP with γ‐rays. Effect of reaction conditions on the degree of grafting such as total radiation dose, monomer concentration, temperature, and time of grafting has been studied. From the study, it is seen that the degree of grafting is strongly dependent on the reaction conditions. The rate dependence of 0.53 (∼0.5) and 1.03 (∼1) have been obtained with respect to total dose and monomer concentration, respectively indicating that radiation induced grafting follows free radical polymerization. The activation energy for the grafting in the temperature range of 60–90°C is found to be 33 kJ/mol. The results indicate that the grafting takes place by the front mechanism where the grafting starts at surface and slowly proceeds inwards by diffusion of the monomer through the swollen grafted chains. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2572–2577, 2003
Effect of molecular structure of styrene–butadiene block copolymers on morphology, rheological properties, and impact strength of polystyrene/polyethylene blends
Authors: Fortelný Ivan , Mikešová Jana , Hromádková Jiřina , Hašová Věra , Horák Zdeněk 
Published: September 2003

AbstractThe effect of molecular structure of six model styrene–butadiene (SB) block copolymers with various number of blocks and two lengths of styrene blocks on morphology, rheological properties, and impact strength of polystyrene (PS)/high‐density polyethylene (PE) blends was studied. It was found that location of SB copolymers in the blends is determined by the length of styrene blocks. The length of styrene blocks has similar effects on impact strength and linear viscoelastic properties of the blends. On the other hand, the correlation was not found between the effects of a number of blocks on impact strength and linear viscoelastic properties of the blends. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2303–2309, 2003
Polymer gel electrolytes based on thermoplastic polyurethane
Authors: Tian Li‐ying , Zhu Wei‐hua , Tang Xiaozhen 
Published: September 2003

AbstractSeries of gel electrolytes based on thermoplastic polyurethane (PU) with different organic additives were prepared and studied. Structural characterization was carried out by differential scanning calorimetry (DSC), dynamic mechanical analyzer (DMA), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The results showed that propylene carbonate (PC), N,N‐dimethylformamide (DMF), polyethyleneglycol 400 (PEG400), and glycerol played roles of plasticizers and were miscible with soft‐segment in PU matrix, which led to increase of the polymer segmental mobility, which in turn led to decrease of glass transition temperature (Tg), while, diethyl carbonate (DEC) and diethylene glycol dimethyl ether (DGDE) showed no effectiveness of plasticizers. Ionic conductive properties of the electrolytes, examined by complex impedance analyzer, showed that ionic conductivities of the samples increased with the increase of organic additive content, and the sample with PEG400 as organic additive showed an ionic conductivity of 1.8 × 10−5 S cm−1 at room temperature. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2310–2315, 2003
Mechanical and thermal properties of phenolic resin‐layered silicate nanocomposites synthesized by melt intercalation
Authors: Choi Min Ho , Chung In Jae 
Published: September 2003

AbstractPhenolic resin–layered silicate nanocomposites (PLSNs) were synthesized by melt intercalation with linear novolac resin (P1) and organosilicates such as montmorillonite modified by benzyldimethyloctadecylammonium (C18BM) and by bis(2‐hydroxy‐ethyl)methyl tallow ammonium (THEM). The PLSNs were prepared by a sequential process (IC) in which phenolic resin was melt‐intercalated into organosilicate and subsequently cured with hexamethylenetetramine (HMTA). It was found from X‐ray diffraction measurements that P1THEMIC nanocomposites showed better silicate dispersion than did P1C18BMIC nanocomposites, even though both systems had intercalated morphologies. The larger silicate gallery expansion in P1THEMIC nanocomposites was attributed to the strong hydrogen‐bonding interaction between the phenolic resin and hydroxyl groups of the organic modifier of THEM. As they had better silicate dispersion, the P1THEMIC nanocomposites showed better mechanical properties than the P1C18BMIC nanocomposites. The thermal stability of the P1THEMIC nanocomposites was slightly increased or decreased, depending on the silicate content, relative to the neat phenolic resin. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2316–2321, 2003
Compatibilization of polymer blends from poly(styrene‐co‐acrylonitrile) and polycarbonate by oxazoline modification of poly(styrene‐co‐acrylonitrile) in the melt
Authors: Gordon Becker Hinnerk , Schmidt‐Naake Gudrun 
Published: September 2003

AbstractA good way of achieving compatibility in polymer blends of poly(styrene‐co‐acrylonitrile) (S/AN) and bisphenol A polycarbonate (PC) is the chemical modification of S/AN in the melt. A catalyzed reaction of the nitrile groups with a substituted 2‐amino alcohol or 2‐amino phenol resulted in a conversion of nitrile groups of 55–75% in 60 min. The introduced heterocyclic structures were ethyl hydroxymethyl oxazoline (EHMOXA) and benzoxazole (BenzOXA), respectively. The use of dibutyltin oxide as a catalyst led to the highest efficiency. The modified polymer was characterized by Fourier transform infrared and NMR spectroscopy, elemental analysis, and reactions with organic acids and anhydrides. The modified S/AN showed good technical compatibility (single glass‐transition temperature) with PC in blends made from solution and from the melt. All blends were characterized with oscillating rheometry and differential scanning calorimetry. Rheological measurements showed that EHMOXA–S/AN reacted with PC and had crosslinked structures, whereas BenzOXA–S/AN showed compatibilization without any (crosslinking) reaction. The melt blends of BenzOXA–S/AN and PC showed a downward shift in the complex viscosity due to the influence of the BenzOXA group. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2322–2332, 2003
Synthesis and characterization of conducting poly(aniline‐co‐diaminodiphenylsulfone) copolymers
Authors: Dan Ananya , Sengupta P. K. 
Published: September 2003

AbstractPolyaniline, poly(aniline‐co‐4,4′‐diaminodiphenylsulfone), and poly(4,4′‐diaminodiphenylsulfone) were synthesized by ammonium peroxydisulfate oxidation and characterized by a number of techniques, including infrared spectroscopy, ultraviolet–visible absorption spectroscopy, 1H‐NMR, thermogravimetric analysis, and differential scanning calorimetry. These copolymers had enhanced solubility in common organic solvents in comparison with polyaniline. The conductivities of the HCl‐doped polymers ranged from 1 S cm−1 for polyaniline to 10−8 S cm−1 for poly(4,4′‐diaminodiphenylsulfone). The copolymer compositions showed that block copolymers of 4,4′‐diaminodiphenylsulfone (r1 > 1) and aniline (r2 < 1) formed and that the reactivity of 4,4′‐diaminodiphenylsulfone was greater than that of aniline. The results were explained by the effect of the SO2 group present in the polymer structure. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2337–2347, 2003
Reducing the contents of free phenol and formaldehyde in phenolic foam
Authors: Li Wanli , Lin Qiang , Yan Mingfa , Zou Yousi 
Published: September 2003

AbstractThe problem of overly high contents of remnant monomers (free phenol and free formaldehyde) in phenolic foam was studied. Free phenol was characterized by iodimetry, and free formaldehyde was characterized by a hydroxylamine hydrochloride method. The effect of the phenol/formaldehyde molar ratios and the reaction temperature on the contents of the remnant monomers was examined. The effect of adding urea on the content of free formaldehyde was investigated. The effect of the foaming process on the contents of the remnant monomers was examined in detail. Phenolic foams in which the content of free phenol was 0.09% and the content of free formaldehyde was less than 0.1% were successfully prepared. A prepolymer of polyurethane, which toughened the phenolic foam, lowered the contents of free phenol and free formaldehyde. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2333–2336, 2003
On the correlation between characteristics of topological and molecular structures and mechanical properties of NR/chlorinated polyethylene rubbers
Authors: Jurkowska Barbara , Jurkowski Boleslaw 
Published: September 2003

AbstractChlorinated polyethylene (CPE) taken as a modifier for NR rubber compound changes the mechanical properties of their vulcanizates. With the help of a novel thermomechanical methodology it was found that it also influences the structures of both the tested master batches and the vulcanizates. Some characteristics of the structure of NR/CPE rubbers obtained by using thermomechanical analysis (TMA) correlate satisfactorily with their mechanical properties measured at static and dynamic conditions. This supports our previous conclusion about the suitability of TMA to study some of the underlying reasons for changes in rubber properties resulting from rubber formulation, compounding, and processing. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2583–2591, 2003
Thermoplastic elastomeric blend of nitrile rubber and poly(styrene‐co‐acrylonitrile). II. Replacement of nitrile rubber by its vulcanizate powder
Authors: Anandhan S. , De P. P. , Bhowmick Anil K. , De S. K. , Bandyopadhyay S. 
Published: September 2003

AbstractA model waste nitrile rubber powder (w‐NBR) was prepared by ambient grinding of aged NBR vulcanizate based on an oil seal formulation. The w‐NBR was characterized by scanning electron microscopic and optical microscopic techniques. Virgin nitrile rubber in a thermoplastic elastomeric 70:30 nitrile rubber/poly(styrene‐co‐acrylonitrile) (SAN) blend was replaced by w‐NBR, and the mechanical properties and swelling index were determined. The virgin NBR in the blend was replaced by the rubber present in w‐NBR (r‐w‐NBR) and the optimum mechanical properties were achieved at 45% replacement where the blend was still reprocessable. Transmission electron microscopic and atomic force microscopic studies reveal that w‐NBR particles coated with NBR are dispersed in a continuous SAN matrix. It was observed that migration of unreacted curatives from w‐NBR to virgin NBR is not significant and incorporation of curatives is necessary for attainment of optimum level of mechanical properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2348–2357, 2003