bluuebunny/crossref_metadata_2025_split huggingface dataset:
Testing for genetic associations with the PAX gene family in a spina bifida population
Authors: Volcik K.A. , Blanton S.H. , Kruzel M.C. , Townsend I.T. , Tyerman G.H. , Mier R.J. , Northrup H. 
Published: October 2002

AbstractNeural tube defects (NTDs) are among the most common severely disabling birth defects in the United States, affecting approximately 1–2 of every 1,000 live births. The etiology of NTDs is multifactorial, involving the combined action of both genetic and environmental factors. A nonparametric linkage method, the transmission disequilibrium test (TDT), was utilized to determine if the genes in the PAX family play a role in the formation of NTDs. DNA from 459 spina bifida (SB) patients and their parents (430 mothers and 239 fathers, for a total population of 1,128 subjects) was tested for linkage and association utilizing polymorphic markers from within or very close to the PAX genes of interest. Significant findings were obtained for the following markers: marker locus D20S101 flanking the PAX1 gene (P = 0.019), marker locus D1S228 within the PAX7 gene (P = 0.011), and marker locus D2S110 within the PAX8 gene (P = 0.013). Even though our findings are only mildly significant, given the known expression patterns of the PAX genes in development and the availability of their sequences, we elected to follow up these results by testing these genes directly for mutations utilizing single‐strand conformational analysis (SSCA) and direct sequencing. Multiple variations were detected in each of the PAX genes with significant TDT results; however, these variations were not passed from parent to child in phase with the positively transmitted allele. Therefore, it is unlikely that these variations contribute to susceptibility for SB, but rather are previously unreported polymorphisms. © 2002 Wiley‐Liss, Inc.
Parental origin of normal X chromosomes in Turner syndrome patients with various karyotypes: Implications for the mechanism leading to generation of a 45,X karyotype
Authors: Uematsu Ayumi , Yorifuji Tohru , Muroi Junko , Kawai Masahiko , Mamada Mitsukazu , Kaji Masayuki , Yamanaka Chutaro , Momoi Toru , Nakahata Tatsutoshi 
Published: October 2002

AbstractThe parental origin of the X chromosome of 45,X females has been the subject of many studies, and most of them have shown that the majority (60–80%) of the X chromosomes are maternal in origin. However, studies on the parental origin of normal X chromosomes are relatively limited for Turner syndrome (TS) females with sex chromosome aberrations. In this study, we used PCR‐based typing of highly polymorphic markers and an assay of methylation status of the androgen receptor gene to determine the parental origin of normal X chromosomes in 50 unbiased TS females with a variety of karyotypes. Our results showed a higher paternal meiotic error rate leading to the generation of abnormal sex chromosomes, especially in the case of del(Xp) and abnormal Y chromosomes. Isochromosome Xq and ring/marker X chromosomes, on the other hand, were equally likely the result of both maternal and paternal meiotic errors. A thorough review of previous results, together with our data suggests, that the majority of TS karyotype are caused by paternal meiotic errors that generate abnormal sex chromosomes, and that most 45,X cells are generated by mitotic loss of these abnormal sex chromosomes, resulting in maternal X dominance in these cells. © 2002 Wiley‐Liss, Inc.
Abnormal sterol metabolism in a patient with Antley‐Bixler syndrome and ambiguous genitalia
Authors: Kelley Richard I. , Kratz Lisa E. , Glaser Rivka L. , Netzloff Michael L. , Miller Wolf Linda , Jabs Ethylin W. 
Published: October 2002

AbstractAntley‐Bixler syndrome (ABS) is a rare multiple anomaly syndrome comprising radiohumeral synostosis, bowed femora, fractures of the long bones, premature fusion of the calvarial sutures, severe midface hypoplasia, proptosis, choanal atresia, and, in some, ambiguous genitalia. Of fewer than 40 patients described to date, most have been sporadic, although reports of parental consanguinity and affected sibs of both sexes suggests autosomal recessive inheritance in some families. Known genetic causes among sporadic cases of ABS or ABS‐like syndromes are missense mutations in the IgII and IgIII regions ofFGFR2, although the assignment of the diagnosis of ABS to such children has been disputed. A third cause of an ABS‐like phenotype is early in utero exposure to fluconazole, an inhibitor of lanosterol 14‐alpha‐demethylase. The fourth proposed cause of ABS is digenic inheritance combining heterozygosity or homozygosity for steroid 21‐hydroxylase deficiency with effects from a second gene at an unknown locus. Because fluconazole is a strong inhibitor of lanosterol 14‐alpha‐demethylase (CYP51), we evaluated sterol metabolism in lymphoblast cell lines from an ABS patient without a knownFGFR2mutation and from a patient with anFGFR2mutation and ABS‐like manifestations. When grown in the absence of cholesterol to stimulate cholesterol biosynthesis, the cells from the ABS patient with ambiguous genitalia but without anFGFR2mutation accumulated markedly increased levels of lanosterol and dihydrolanosterol. Although the abnormal sterol profile suggested a deficiency of lanosterol 14‐alpha‐demethylase, mutational analysis of its gene,CYP51, disclosed no obvious pathogenic mutation in any of its 10 exons or exon‐intron boundaries. Sterol metabolism in lymphoblasts from the phenotypically unaffected mother was normal. Our results suggest that ABS can occur in a patient with an intrinsic defect of cholesterol biosynthesis at the level of lanosterol 14‐alpha‐demethylase, although the genetic nature of the deficiency remains to be determined. © 2002 Wiley‐Liss, Inc.
Interstitial microdeletion of chromosome 1p in two siblings
Authors: Campbell C.G.N. , Wang H. , Hunter G.W. 
Published: October 2002

AbstractTwo half‐siblings are described with what we believe to be the second and third cases identified of the microdeletion, del(1)(p32.1p32.3). Both siblings had a tethered cord and had mental retardation, but otherwise their phenotypic presentations were quite different. The sister had failure to thrive, congenital dysplasia of the hip, absent corpus callosum, Chiari I malformation, and syringomyelia. The brother experienced neonatal seizures secondary to a hemorrhagic stroke. He had an accessory thumb, inguinal hernia, cryptorchidism, urinary reflux, and cholelithiasis. Although these children have only delayed development in common with the previously reported case, they help to further define chromosomal deletions in this area of chromosome 1. As yet, no clear phenotypic picture has emerged. © 2002 Wiley‐Liss, Inc.
Hand and body position during locomotor behavior in the aye‐aye (Daubentonia madagascariensis)
Authors: Krakauer Elissa , Lemelin Pierre , Schmitt Daniel 
Published: October 2002

AbstractAye‐ayes (Daubentonia madagascariensis) have unique hands among primates, with extraordinarily long fingers in relation to body size. These long digits may be vulnerable to damage from forces during locomotion, particularly during head‐first descent—a locomotor mode that the aye‐aye utilizes frequently. Previous behavioral studies of aye‐aye locomotion reported that Daubentonia must curl its fingers during horizontal quadrupedalism and/or descent to reduce potential stresses on its long fingers. To test this hypothesis, we examined hand and body position in three captive adult aye‐ayes while they walked quadrupedally on horizontal and oblique branches. Substantial variation in hand position was observed among individuals for each substrate orientation. While hand postures with curled fingers were preferred by one individual during descent, they were not preferred by the other two individuals, contrary to our expectations. Differences in body position were more consistent among all three individuals. The angle of the body relative to the substrate was significantly reduced during descent (8.4°) compared to horizontal locomotion (16.9°). These results suggest that changes in body position, rather than hand position, may help reduce stresses on the digits. A biomechanical model is proposed that demonstrates how a reduction in the body angle in relation to substrate may act to move the center of mass more caudally. This mechanism of moderating loads by altering body position, rather than hand position, may represent an important functional aspect of arboreal locomotion in aye‐ayes and other primates. © 2002 Wiley‐Liss, Inc.
Out of the mouths of baboons: Stress, life history, and dental development in the Awash National Park hybrid zone, Ethiopia
Authors: Dirks Wendy , Reid Donald J. , Jolly Clifford J. , Phillips‐Conroy Jane E. , Brett Frederick L. 
Published: October 2002

AbstractThe techniques of dental histology provide a method for reconstructing much of the life history of an individual, as accentuated increments visible in polarized light microscopy record incidents of physiological stress during the formation of dental tissues. Combined with counts of the normal periodic growth increments, they provide a means of reconstructing the chronology of dental development, age at death, and the ages at which stress occurs. In this study, we determine age at death and reconstruct the chronology of dental development in two male anubis baboons from Uganda and two female baboons from the Awash National Park hybrid zone. For the female baboons, we used the dates of death and rainfall records for the region to determine date of birth, ages at periods of physiological stress, dates at which these stresses occurred, and rainfall amounts for those months.Ages determined histologically for each specimen are comparable to ages estimated from dental emergence schedules and dental scores for wild baboons. Crown formation times are longer than those reported in radiographic studies of captive yellow baboons. Age at initiation of crown formation is similar to that reported for radiographic studies, but ages at completion of crown formation are consistently later. The pattern of stresses is similar in the two female baboons, suggesting that individual life history intersects with local ecology to produce a pattern of accentuated increments occurring during the weaning process and at the onset of menarche, as well as during the first postweaning dry and rainy periods. Am J Phys Anthropol 118:239–252, 2002. © 2002 Wiley‐Liss, Inc.
Diffuse signal abnormalities in the spinal cord in multiple sclerosis: Direct postmortem in situ magnetic resonance imaging correlated with in vitro high‐resolution magnetic resonance imaging and histopathology
Authors: Bergers Elisabeth , Bot Joost C. J. , van der Valk Paul , Castelijns Jonas A. , Lycklama A Nijeholt Geert J. , Kamphorst Wouter , Polman Chris H. , Blezer Erwin L. A. , Nicolay Klaas , Ravid Rivka , Barkhof Frederik 
Published: October 2002

AbstractIn this study, we compared direct postmortem in situ (whole‐corpse) sagittal spinal cord magnetic resonance imaging (1.5T) of 7 multiple sclerosis cases with targeted high‐resolution in vitro axial magnetic resonance imaging (4.7T) and histopathology. On sagittal in situ magnetic resonance imaging, 1 case had a normal spinal cord, 2 had only focal lesions, 3 had a combination of focal and diffuse abnormalities, and 1 had only diffuse abnormalities. All spinal cords showed abnormalities on high‐resolution magnetic resonance imaging and histopathology, confirming the existence of diffuse cord changes as genuine multiple sclerosis‐related abnormalities while highlighting the limited resolution of in vivo magnetic resonance imaging.
Application of the new McDonald criteria to patients with clinically isolated syndromes suggestive of multiple sclerosis
Authors: Dalton Catherine M. , Brex Peter A. , Miszkiel Katherine A. , Hickman Simon J. , MacManus David G. , Plant Gordon T. , Thompson Alan J. , Miller David H. 
Published: October 2002

AbstractTraditionally, multiple sclerosis (MS) has been diagnosed on the basis of clinical evidence of dissemination in time and space. Previously, it could not be diagnosed in patients with single clinical episodes of demyelination known as clinically isolated syndromes. New diagnostic criteria from the International Panel of McDonald and colleagues incorporate MRI evidence of dissemination in time and space to allow a diagnosis of MS in patients with clinically isolated syndromes. From clinical and MRI examinations performed prospectively at baseline, 3 months, 1 year, and 3 years of follow‐up, the frequency of developing MS was ascertained by the application of both the new McDonald criteria and the Poser criteria for clinically definite MS. The specificity, sensitivity, positive and negative predictive value, and accuracy of the new criteria for the development of clinically definite MS were assessed. At 3 months, 20 of 95 (21%) patients had MS with the McDonald criteria, whereas only 7 of 95 (7%) had developed clinically definite MS. After 1 year, the corresponding figures were 38 of 79 (48%) and 16 of 79 (20%), and after 3 years, they were 29 of 50 (58%) and 19 of 50 (38%). The development of MS with the new MRI criteria after 1 year had a high sensitivity (83%), specificity (83%), positive predicative value (75%), negative predictive value (89%), and accuracy (83%) for clinically definite MS at 3 years. Use of the new McDonald criteria more than doubled the rate of diagnosis of MS within a year of presentation with a clinically isolated syndrome. The high specificity, positive predictive value, and accuracy of the new criteria for clinically definite MS support their clinical relevance.
Vertebrobasilar stroke as a late complication of a Blalock‐Taussig shunt
Authors: Gailloud Philippe , Hillis Argye , Perler Bruce , Murphy Kieran J. 
Published: October 2002

AbstractWe describe a 39‐year‐old patient with a cerebellar infarct and a history of a tetralogy of Fallot corrected during childhood. This is the first documented case of vertebrobasilar stroke occurring as a late complication of a Blalock‐Taussig shunt followed by total cardiac repair.
Model compound release from DL‐lactide/ε‐caprolactone copolymers and evaluation of specific interactions by molecular modeling
Authors: Rich Jaana , Karjalainen Teija , Ahjopalo Lisbeth , Seppälä Jukka 
Published: October 2002

AbstractThe applicability of poly(DL‐lactide‐co‐ϵ‐caprolactone) copolymers P(DL‐LA/CL) for controlled‐release devices was evaluated. The copolymers of DL‐lactide and ϵ‐caprolactone were polymerized in bulk using Sn(II)octoate as the initiator. The release of three model compounds, theophylline, propranolol hydrochloride, and lidocaine (10 wt%), from high‐lactide content copolymer was studied. The results showed that the copolymer with only minor caprolactone content was not suitable for controlled release of these small‐molecular weight model compounds in matrix‐type devices. A burst in the release rate was observed when the degradation of the matrix replaced diffusion‐controlled release. Increasing the permeation properties of the copolymer matrix through blending and using a different comonomer ratio with an increased caprolactone content were both studied. A release that was more controlled but relatively slow was obtained by using copolyester blends as release matrices. Hydrolytic degradation of the copolymers was also recorded, and the copolymers were found to be very susceptible to hydrolytic chain scission at 37°C. Molecular modeling studies were performed to study the interactions between the theophylline model compound and the homo‐ and copolymers of lactide and ε‐caprolactone units. In agreement with experimental results, the calculations showed increasing interaction between theophylline and the polymer matrix as a function of increasing amount of lactide units. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1–9, 2002
pH‐ and thermal characteristics of graft hydrogels based on chitosan and poly(dimethylsiloxane)
Authors: Kim In Young , Kim Seon Jeong , Shin Mi‐Seon , Lee Young Moo , Shin Dong‐Ic , Kim Sun I. 
Published: October 2002

AbstractGraft copolymerization of epoxy‐terminated poly(dimethylsiloxane) (PDMS) onto chitosan was reacted without using a catalyst. pH‐sensitive hydrogels were obtained that are based on two different components: a natural polymer and a synthetic polymer. These PDMS substitutents provide the basis for hydrophobic interactions that contribute to the formation of hydrogels. Various graft hydrogels were prepared from different weight ratios of chitosan and PDMS. Swelling behavior of these hydrogels was studied by immersion of the gels in various buffer solution. Photocrosslinked hydrogels exhibited a high equilibrium water content (EWC). Particularly, the sample CP31 of the highest chitosan–PDMS weight ratio showed the highest EWC in time‐dependent, temperature‐dependent, and pH‐dependent swelling behavior. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2661–2666, 2002
Transport properties and mechanical behavior of poly(methyl‐phenylsiloxane) membranes as a function of methyl to phenyl groups ratio
Authors: Erdmann E. , Destéfanis H. A. , Abalos R. , Frontini P. M. , Abraham G. A. 
Published: October 2002

AbstractMembranes based on dimethyl and methyl‐phenylsiloxane were synthesized and then fully characterized. Transport properties and mechanical behavior were determined as a function of different methyl/phenyl group ratios and the effects of these groups on results were established. Membrane transport properties were evaluated from n‐hexane absorption studies. Static tensile stress–strain deformation measurements, stress–hysteresis determination, and stress–relaxation studies were performed to assess the mechanical behavior of these membranes. The results indicate that both physical–mechanical and transport properties are strongly affected by the methyl group content. The increase of the phenyl groups in the polymer chain impairs mechanical properties as a result of which decrease in crosslinking degree and gas permeability due to the diminution in free volume and penetrant solubility. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1624–1633, 2002
Protective flexible coatings on copper by spontaneous polymerization
Authors: Zheng Haipeng , Nainani Kamal , Bell James P. 
Published: October 2002

AbstractSpontaneous polymerization (S‐Poly) is a novel process for forming protective polymer coatings on metals. The S‐Poly mechanism on copper is discussed for one typical monomer system. Poly(ethylene glycol) ethyl ether methacrylate (EEM), a flexible monomer, was first introduced into a styrene/N‐phenyl maleimide system that we had used for aluminum and steel. The effects of EEM on the composition, apparent molecular weight, thermal properties, and other properties of the coatings were studied with reflectance Fourier transform infrared, gel permeation chromatography, differential scanning calorimetry, and water‐uptake and adhesion experiments. N‐(4‐Fluorophenyl) maleimide (4FMI), a strongly hydrophobic monomer, was further incorporated into the EEM copolymer for improved water impermeability. The resultant coatings, which included EEM and 4FMI units, showed good bonding strength to copper and better ductility and protective properties than other coatings in both corrosion and pinhole tests. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1749–1757, 2002
An examination of the shear‐thickening behavior of high molecular weight polymers dissolved in low‐viscosity Newtonian solvents
Authors: Edwards B. J. , Keffer D. J. , Reneau C. W. 
Published: October 2002

AbstractThe anomaly of shear thickening at high shear rates can be observed under certain conditions for high molecular weight polymers dissolved in low‐viscosity Newtonian solvents despite the fact that shear‐thinning behavior is considered the norm for these fluids. The nature of the shear‐thickening region of the flow curve is examined herein through the application of a recent rheological model that has the capability of quantifying not only the rheological properties of the material, but its internal microstructural state as well. The results of this examination provide a self‐consistent explanation of the full flow characterization of this anomalous behavior, including both rheological and optical experimental measurements. The results presented herein suggest that the shear‐thickening behavior is actually caused by the destruction of structures formed during shear at lower shear rates, not by their formation, as previously assumed. The linear birefringence and linear dichroism observed experimentally in correlation with the shear‐thickening behavior are well described by the rheological model and give predictions in line with experimental measurements. Furthermore, quantitative predictions are made for rheological characteristic functions, such as the first and second normal‐stress coefficients, for which experimental measurements for these solutions have not yet been made. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1714–1735, 2002
Immobilization of a cyclodextrin glucanotransferase (CGTase) onto polyethylene film with a carboxylic acid group and production of cyclodextrins from corn starch using CGTase‐immobilized PE film
Authors: Choi Seong‐Ho , Kim Min‐Seok , Ryoo Jae Jeong , Lee Kwang‐Pill , Shin Hyun‐Dong , Kim Sun‐Hwa , Lee Yong‐Hyun 
Published: October 2002

AbstractCarboxylic acid groups were introduced onto polyethylene (PE) film by radiation‐induced graft copolymerization. Subsequently, the clodextrin glucanotransferase (CGTase) was immobilized on the PE film with a carboxylic acid group. The activity of the immobilized CGTase on PE film was in the range of 0.40–1.04 U/cm2 per min. The production of cyclodextrins (CDs) from corn starch was examined using the CGTase‐immobilized PE film. The production ratios of CDs using CGTase‐immobilized PE film was in the following order: α–CD > β–CD > γ–CD. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2451–2457, 2002
Permeation of mixtures of organic liquids through polymeric membranes: Role of liquid–liquid interactions
Authors: Perron Gérald , Desnoyers Jacques E. , Lara Jaime 
Published: October 2002

AbstractThe permeation of pure organic liquids and mixtures of organic liquids through commercial butyl, neoprene, and nitrile membranes was studied using dynamic material deformation (swelling) and permeation techniques. The derived parameters, the breakthrough time (tBT), steady‐state permeation rate (SSPR), and initial swelling rate (SR), show deviations from additivity for the mixtures, based on the parameters of the pure liquids on a mol fraction basis. In the majority of cases for the three membranes examined, the deviations are independent of the nature of the membranes, and the signs of the deviations for tBT are opposite to those for SSPR or SR, provided that the membranes are not degraded by one of the solvents. An approach that considers only solvent–solvent interactions based on the enthalpy of mixing was used to predict deviations for mixtures. For mixtures where the enthalpy of mixing is large and exothermic, the permeation of the mixture is less than expected, while for systems where the enthalpy of mixing is large and endothermic, the permeation is larger than expected. A simple semiempirical model predicts the sign and magnitude of the permeation of 73% of the system–permeation property combinations investigated, which show significant deviations from ideality. It is interesting to note that the wrong predictions are for systems where the predictions are positive, that is, for SSPR and SR rates with endothermic systems and for tBT with exothermic systems. The exceptions also seem to be for systems that correspond to materials having a high resistance to one of the solvents and a very low resistance to the other solvent. Examples of ternary–mixture permeation data are also given and show that, even if two of the pure components do not permeate through a membrane, the membrane will offer little protection if the third component shows a high affinity for the membrane and if the enthalpies of mixing of this component with the other liquids are endothermic. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 195–215, 2002