bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigative modalities for massive lower gastrointestinal bleeding
Authors: Al Qahtani Aayad R. , Satin Richard , Stern Jerry , Gordon Philip H.
Published: October 2002

The objective of this study was to evaluate the efficacy of various diagnostic modalities in the assessment of patients with massive lower gastrointestinal bleeding. The charts of all patients admitted to a McGill University affiliated teaching hospital with the diagnosis of lower gastrointestinal bleeding over a 25‐year period were reviewed. There were 136 patients who underwent 202 admissions. The information documented included demographics on age, gender, co‐morbid disease, prescribed medications, requirements for blood transfusions, orthostatic change in blood pressure, acute drop in hematocrit (to <30%), and exclusion of upper gastrointestinal bleeding. Among the 202 admitted patients there were 116 men and 86 women), with an average age of 70 years (range 16–95 years). At least one significant medical disease was found in 93% of these patients; and 20% were on aspirin and 5% on anticoagulants at the time of diagnosis. Rigid or flexible sigmoidoscopy was performed in 68 and 18 patients, respectively, with a definitive diagnosis made in 2.9% and 11.0%, respectively. Colonoscopy was performed in 152 cases, 20 of which were incomplete; a specific diagnosis was made for 59 admissions (45%). A red blood cell or colloid scan was performed on 53 patients, with extravasation noted in 13 (24.5%); a localized site of bleeding was identified in 9 cases (17%). Angiography was performed on 31 patients with bleeding sites localized in 6 (19%). Barium enemas were completed in 85 of 92 patients, and the presumptive cause of bleeding was identified in 72% of those with a complete examination. The most common causes identified were diverticulosis in 52 patients and angiodysplasia in 14. The cause of bleeding was not detected in 48 (35%). Bleeding stopped in most patients spontaneously, with only 7 requiring operation. The average number of units transfused was 3 (range 0–26). Scintigraphy and angiography were less efficacious than colonoscopy for localizing the site and etiology of the bleeding. Despite the combination of investigative modalities, a definitive diagnosis was not made in 35% of the admitted patients. The need for operative intervention in our study was lower than in most previous reports.
Atrial fibrillation and minimally invasive coronary artery bypass grafting: Risk factor analysis
Authors: Mueller Xavier M. , Tevaearai Hendrik T. , Ruchat Patrick , Stumpe Frank , von Segesser Ludwig K.
Published: October 2002

Atrial fibrillation (AF) is a frequent arrhythmia after conventional coronary artery bypass grafting. With the advent of minimally invasive technique for left internal mammary artery‐left anterior descending coronary artery (LIMA‐LAD) grafting, we analyzed the incidence and the risk factors of postoperative AF in this patient population. This prospective study involves all patients undergoing isolated LIMA‐LAD grafting with minimally invasive technique between January 1994 and June 2000. Twenty‐four possible risk factors for postoperative AF were entered into univariate and multivariate logistic regression analyses. Postoperative AF occurred in 21 of the 90 patients (23.3%) analyzed. Double‐ or triple‐vessel disease was present in 12/90 patients (13.3%). On univariate analysis, right coronary artery disease (p<0.01), age (p=0.01), and diabetes (p=0.04) were found to be risk factors for AF. On multivariate analysis, right coronary artery disease was identified as the sole significant risk factor (p=0.02). In this patient population, the incidence of AF after minimally invasive coronary artery bypass is in the range of that reported for conventional coronary artery bypass grafting. Right coronary artery disease was found to be an independent predictor, and this may be related to the fact that in this patient population the diseased right coronary artery was not revascularized at the time of the surgical procedure. For the same reason, this risk factor may find a broader application to noncardiac thoracic surgery.
Formation and use of covariation assessments in the real world
Authors: Coups Elliot J. , Chapman Gretchen B.
Published: October 2002

In this study we examined covariation assessments made using real‐world information held by individual participants about an important preventive health behaviour: receiving an influenza vaccine (‘flu shot’). Four hundred and seventy‐seven healthy adult participants completed a questionnaire, indicating both their personal experience and vicarious experience (knowledge of other people's experiences) with the flu shot and the flu. Additionally, participants provided a covariation assessment by indicating how effective they thought the flu shot is in preventing the flu. We examined whether the experience information was related to the covariation assessment, and whether it in turn was related to the decision to receive a flu shot. Our results indicated that people use a simple intuitive strategy to combine their personal experience information. For vicarious experience information, we found evidence for use of a normative strategy, as well as simpler intuitive strategies. Consistent with our hypothesis, both types of experience information were associated with the effectiveness judgement, which was subsequently related to the decision to obtain a flu shot. Practical applications of these findings are discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Platelet spherocytosis: A new bleeding disorder
Authors: White James G. , de Alarcon Pedro A.
Published: October 2002

The present study evaluated a child with thrombocytopenia and a rare congenital bleeding disorder associated with platelet spherocytosis. Differential interference phase contrast microscopy (DIC) revealed that his platelets were spherical in form. Examination of thin sections in the electron microscope showed that his platelets were nearly devoid of microtubules (MT) and microtubule coils (MTC) that support the discoid shape in 100% of normal platelets. Immunofluorescence with a monoclonal antibody to tubulin, the precursor protein of MT, revealed bright rings in normal cells and diffuse fluorescence of patient platelets. The brightness of the fluorescence emitted by patient platelets was comparable to the diffuse fluorescence of normal platelets after chilling to dissolve intact MT, suggesting normal and patient cells contained comparable amounts of tubulin. Exposure of patient platelets to Taxol, an agent that stabilizes and induces MT, caused MT formation in 82% of patient platelets and MTC development in 11%, resulting in their conversion to discs. Glycoproteins GPIIb/IIIa and GPIb were present on patient platelets, and the cells contained normal numbers of dense bodies, ruling out storage pool disease. The patient's platelets adhered to and spread normally on glass but failed to undergo rapid, irreversible aggregation when stirred with agents that produced a complete response in normal discoid platelets, even when the patient's platelets were concentrated. The poor response of spherical platelets was associated with failure to become irregular and extend long filopodia. Thus, the spherical shape of patient platelets may contribute to the thrombocytopenia and to the clinical bleeding symptoms. Am. J. Hematol. 70:158–166, 2002. © 2002 Wiley‐Liss, Inc.
Cytogenetic findings in reactive lymphoid hyperplasia: Significance of non‐clonal t(3;14) and t(3;22)
Authors: Au Wing Y. , Horsman Douglas E. , Connors Joseph M. , Klasa Richard J. , Gascoyne Randy D.
Published: October 2002

Despite several reports of the molecular detection of recurrent lymphoma translocations in reactive lymph nodes (LN), cytogenetic analysis is seldom performed on such cases. We report the clinical and cytogenetic analysis results on 30 reactive LN. Of these, 17 cases yielded either no growth (n = 9) or normal metaphases only (n = 8), and seven of the 17 patients subsequently developed lymphoma. Lymphoma developed in all 10 patients with a clonal karyotype (median of 2.6 months). Three patients (1 HIV‐positive) had non‐clonal t(3;14) or t(3;22). Their lymphadenopathy resolved spontaneously, and none progressed to lymphoma at 4–6 years of follow‐up. Molecular methods detected a small B‐cell clone in one case and an oligoclonal B‐cell population in the other. Cytogenetic analysis may be useful for interpreting cases of lymphoid hyperplasia. A clonal abnormality is highly predictive of concurrent and/or subsequent lymphoma. A lymphoma‐specific but non‐clonal abnormality does not necessarily herald the development of subsequent lymphoma. Am. J. Hematol. 70:133–138, 2002.© 2002 Wiley‐Liss, Inc.
Spectrum of β‐thalassemia mutations and their association with allelic sequence polymorphisms at the β‐globin gene cluster in an eastern Indian population
Authors: Kukreti Ritushree , Dash Debasis , K E Vineetha , Chakravarty Sanchita , Kr Das Swapan , De Madhusnata , Talukder Geeta
Published: October 2002

In this report, the spectrum of β‐thalassemia mutations and genotype‐to‐phenotype correlations were defined in large number of patients (β‐thalassemia carriers and major) with varying disease severity in an Eastern Indian population mainly from the state of West Bengal. The five most common β‐thalassemia mutations were detected, which included IVS1‐5 (G→C), codon 15 (G→A), codon 26 (G→A), codon 30 (G→C), and codon 41/42 (−TCTT). These accounted for 85% in 80 β‐thalassemic alleles deciphered from 56 patients, including β‐thalassemia major and carriers, and 15% of alleles remained uncharacterized in these patients. Expression of the human β‐globin gene is regulated by an array of cis‐acting DNA elements, including five DNase I hypersensitive sites (HSs) in the locus control region (LCR), promoters that incorporate certain silencer elements, and enhancers at 3′ of the β‐globin gene. For detailed studies and to understand the molecular basis of β‐thalassemia, we studied two groups of subjects: a group of 12 patients from four families having β‐thalassemia major and carrier phenotype and a control group of 26 healthy individuals. In these two groups, we examined portions of the β‐globin gene locus control region HSs 1, 2, 3, and 4, which included the (CA)x(TA)y repeat motif, the (AT)xNy(AT)z repeat motif, the inverted repeat sequence TGGGGACCCCA, the promoter region of the Gγ‐globin gene, an (AT)x(T)y repeat 5′ of the silencer region, and the β‐globin gene and its 3′ flanking region. We investigated the allelic sequence polymorphisms in these regions and their association with the β‐thalassemia mutations to know the possible genotype–phenotype relationship in β‐thalassemia patients. An analysis of cis‐acting regulatory regions showed varied sequence haplotypes associated with some frequent β‐thalassemia mutations in this Eastern Indian population. Am. J. Hematol. 70:269–277, 2002. © 2002 Wiley‐Liss, Inc.
Arsenic trioxide in the treatment of newly diagnosed acute promyelocytic leukemia: A single center experience
Authors: Mathews Vikram , Balasubramanian Poonkuzhali , Shaji Ramachandran Velayudhan , George Biju , Chandy Mammen , Srivastava Alok
Published: October 2002

Arsenic trioxide (As2O3) has been found effective in the treatment in the treatment of acute promyelocytic leukemia (APML). Most studies with As2O3 involve patients with APML who have relapsed following standard therapy. Between January 1998 and July 2000, 14 patients were recruited for an ongoing trial of As2O3 in the treatment of newly diagnosed APML. Arsenic trioxide was administered at a dose of 10 mg/day until complete remission (CR) was achieved. Afterward, a consolidation course and a maintenance schedule consisting of As2O3 as a single agent were administered over 6 months. There were 3 early deaths related to intra‐cerebral hemorrhage: two on day 3 and one on day 4. Of the 11 evaluable patients, one died on day 21 secondary to uncontrolled sepsis, while the remaining 10 (91%) have attained CR. The average time to CR was 52.3 days (range: 34–70 days). One patient developed an isolated central nervous system (CNS) relapse and subsequently went into a second CR following therapy with triple intrathecal chemotherapy, cranial irradiation, and an additional 4‐week course of systemic As2O3. This patient, as well as the remaining nine, has continued to remain in CR at a median follow up of 15 months (range: 2−33 months). Eight out of 10 patients achieved molecular remission at variable periods during their consolidation and maintenance schedules. One patient developed an ATRA syndrome and was administered daunorubicin (40 mg/day) for 2 days. The side effects with this therapy were minimal and did not require cessation of therapy in any patient. There was no significant hepatic toxicity. In our experience, arsenic trioxide is effective in inducing and maintaining remission in patients with APML with minimal side effects. The optimal regimen and total dose required need to be defined. Am. J. Hematol. 70:292–299, 2002. © 2002 Wiley‐Liss, Inc.
Age‐related decrease in energy expenditure at rest parallels reductions in mass of internal organs
Authors: Puggaard Lis , Bjørnsbo Kirsten Schroll , Kock Kirsten , Lüders Kurt , Thobo‐Carlsen Brit , Lammert Ole
Published: October 2002

This study explores to what extent the mass of internal organs may impact the age‐related decrease in energy expenditure at rest (EErest). The relationship between direct measurements of EErest in elderly women and predicted EErest based on equations deriving from the metabolic activity in tissue from younger women were also elucidated. Body composition of elderly women was measured by an impedance method. EErest was measured by the Douglas bag method after an overnight fast. These data were compared with predicted values of EErest based on equations derived from studies in younger women. The mass of internal organs was obtained from autopsy material. Young women (mean age 31.7 years, range 14–60, n = 104) and elderly women of 65 years (n = 22), 75 years (n = 26), and 85 years (n = 31) participated in this study. Autopsy data were obtained from women (n = 238) from the same birth cohorts as the elderly women who died at ages 42–87 years. EErest showed a progressive age‐related decline, which appeared to parallel a similar reduction in the mass of internal organs derived from autopsy material of women who died at the same ages. In contrast, FFM was identical in the group of 65 and 75‐year‐old women, but was lower in the 85‐year‐old women. Predicted and measured EErest revealed a strong correlation in elderly women. Modest reductions in the mass of internal organs with a high metabolic rate appear to contribute markedly to the decline in EErest observed in aging. Further, it is also possible to predict EErest from the body composition of elderly women using equations developed from younger women. Am. J. Hum. Biol. 14: 486–493, 2002. © 2002 Wiley‐Liss, Inc.
Anything but beryllium: The beryllium industry's corruption of safety information
Authors: Egilman David , Bagley Sarah , Connolly Shannon
Published: October 2002

To the Editor:

Beryllium manufacturers have long recognized the relationship between marketing, compensation claims and fear of Be toxicity. In response, they sponsored researchers who manipulated and influenced medical literature to minimize the consequences of Be exposure to workers and members of the community. This dates back to the 1940s, when the Atomic Energy Council(AEC)Advisory Board on Medicine and Biology established the following policy: "If specific locations or activities of the Atomic Energy Commission and/or its contractors are closely associated with statements and information which would invite or tend to encourage claims against the Atomic Energy Commission or its contractors, such portions of articles to be published should be reworded or deleted" [AEC memo, 1947].
No evidence for linkage of liability to autism toHOXA1in a sample from the CPEA network
Authors: Devlin Bernie , Bennett Pamela , Cook, Edwin H. , Dawson Geraldine , Gonen David , Grigorenko Elena L. , McMahon William , Pauls David , Smith Moyra , Spence M. Anne ,   CPEA Genetics Network, Schellenberg Gerard D.
Published: October 2002

A recent study by Ingram et al. [2000b: Teratology 62:393–405] suggests aHis73Argpolymorphism (A:G) inHOXA1contributes substantially to a liability for autism. Using 68 individuals diagnosed with Autism Spectrum Disorders, they found a significant dearth of G homozygotes and biased transmission of G alleles from parents to affected offspring, especially from mothers. Because the connection betweenHOXA1and liability to autism is compelling, we attempted to replicate their finding using a larger, independent sample from the Collaborative Programs of Excellence in Autism (CPEA) network. In our data, genotype frequencies conform to Hardy‐Weinberg equilibrium; allele transmissions meet Mendelian expectations; and there is no obvious sex‐biased allele transmission. Based on our sample size, calculations suggest that we would have at least 95% power to detect linkage and association even if the A:G polymorphism were to account for only 1% of the heritability of autism. Therefore, although we cannot exclude the possibility that the samples in the two studies are intrinsically different, our data from our sample argue against a major role for HOXA1His73Argin liability to autism. © 2002 Wiley‐Liss, Inc.
Mouse models for mitochondrial disease
Authors: Wallace Douglas C.
Published: October 2002

Mutations in mitochondrial genes encoded by both mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) genes have been implicated in a wide range of neuromuscular diseases. MtDNA base substitution and rearrangement mutations generally inactivate one or more tRNA or rRNA genes and can cause myopathy, cardiomyopathy, cataracts, growth retardation, diabetes, etc. nDNA mutations can cause Leigh syndrome, cardiomyopathy, and nephropathy, due to defects in oxidative phosphorylation (OXPHOS) enzyme complexes; cartilage‐hair hypoplasia (CHH) and mtDNA depletion syndrome, through defects in mitochondrial nucleic acid metabolism; and ophthalmoplegia with multiple mtDNA deletions, caused by adenine nucleotide translocator‐1 (ANT1) mutations. Mouse models have been prepared that recapitulate a number of these diseases. The mtDNA 16S rRNA chloramphenicol (CAP) resistance mutation was introduced into the mouse female germline and caused cataracts and rod and cone abnormalities in chimeras and neonatal lethal myopathy and cardiomyopathy in mutant animals. A mtDNA deletion was introduced into the mouse germline and caused myopathy, cardiomyopathy, and nephropathy. Conditional inactivation of the nDNA mitochondrial transcription factor (Tfam) gene in the heart resulted in neonatal lethal cardiomyopathy, while its inactivation in the pancreatic β‐cells caused diabetes. The ATP/ADP ratio was implicated in mitochondrial diabetes through transgenic modification of the β‐cell ATP‐sensitive K+ channel (KATP). Mutational inactivation of the mouse Ant1 gene resulted in myopathy, cardiomyopathy, and multiple mtDNA deletions in association with elevated reactive oxygen species (ROS) production. Inactivation of uncoupler proteins (Ucp) 1–3 revealed that mitochondrial Δψ regulated ROS production. The role of mitochondrial ROS toxicity in disease and aging was confirmed by inactivating glutathione peroxidase (GPx1), resulting in growth retardation, and by total and partial inactivation of Mn superoxide dismutase (MnSOD; Sod2), resulting in neonatal lethal dilated cardiomyopathy and accelerated apoptosis in aging, respectively. The importance of mitochondrial ROS in degenerative diseases and aging was confirmed by treating Sod2 −/− mice and C. elegans with catalytic antioxidant drugs. © 2001 Wiley‐Liss, Inc.
Mitochondria and degenerative disorders
Authors: Orth M. , Schapira A.H.V.
Published: October 2002

In mammalian cells, mitochondria provide energy from aerobic metabolism. They play an important regulatory role in apoptosis, produce and detoxify free radicals, and serve as a cellular calcium buffer. Neurodegenerative disorders involving mitochondria can be divided into those caused by oxidative phosphorylation (OXPHOS) abnormalities either due to mitochondrial DNA (mtDNA) abnormalities, e.g., chronic external ophthalmoplegia, or due to nuclear mutations of OXPHOS proteins, e.g., complex I and II associated with Leigh syndrome. There are diseases caused by nuclear genes encoding non‐OXPHOS mitochondrial proteins, such as frataxin in Friedreich ataxia (which is likely to play an important role in mitochondrial‐cytosolic iron cycling), paraplegin (possibly a mitochondrial ATP‐dependent zinc metalloprotease of the AAA‐ATPases in hereditary spastic paraparesis), and possibly Wilson disease protein (an abnormal copper transporting ATP‐dependent P‐type ATPase associated with Wilson disease). Huntingon disease is an example of diseases with OXPHOS defects associated with mutations of nuclear genes encoding non‐mitochondrial proteins such as huntingtin. There are also disorders with evidence of mitochondrial involvement that cannot as yet be assigned. These include Parkinson disease (where a complex I defect is described and free radicals are generated from dopamine metabolism), amyotrophic lateral sclerosis, and Alzheimer disease, where there is evidence to suggest mitochondrial involvement perhaps secondary to other abnormalities. © 2001 Wiley‐Liss, Inc.
Distribution, population structure, and conservation of lion‐tailed macaques (Macaca silenus) in the Anaimalai Hills, Western Ghats, India
Authors: Singh Mewa , Singh Mridula , Kumar M. Ananda , Kumara H.N. , Sharma A.K. , Kaumanns W.
Published: October 2002

The lion‐tailed macaque is an endangered species, and hence it is necessary that the remaining populations in the rainforests of the Western Ghats, India, be located and their habitats assessed for effective conservation. The Anaimalai Hills in the state of Tamil Nadu harbor 31 groups of lion‐tailed macaques. However, the rainforest in these hills is highly fragmented. Since lion‐tailed macaques are typically arboreal, the groups have become isolated. Two large rain‐forest complexes in these hills harbor 12 and seven groups, respectively, and the remaining 12 groups inhabit small, isolated forest fragments. Group size ranges from six to 53 individuals, with a mean size of 16.3. In the small forest fragments, the standard deviation (SD) of group size was considerably higher than it was in the larger forest complexes. The disturbed fragments also had a higher variability in group size than the relatively undisturbed habitats. It is believed that fragmentation may impede male migration. We suggest that the fragments be managed in such a way that male migration among groups can be facilitated to overcome the potential effects of isolation. © 2002 Wiley‐Liss, Inc.
Clinical variability in 3‐hydroxy‐2‐methylbutyryl‐coa dehydrogenase deficiency
Authors: Ensenauer Regina , Niederhoff Helmut , Ruiter Jos P. N. , Wanders Ronald J. A. , Schwab K. Otfried , Brandis Matthias , Lehnert Willy
Published: October 2002

We report the identification of two new 7‐year‐old patients with 3‐hydroxy‐2‐methylbutyryl‐CoA dehydrogenase deficiency, a recently described inborn error of isoleucine metabolism. The defect is localized one step above 3‐ketothiolase, resulting in a urinary metabolite pattern similar to that seen for deficiency of the latter. One patient has progressive neurodegenerative symptoms, whereas the clinical phenotype of the other patient is characterized by psychomotor retardation without loss of developmental milestones. A short‐term biochemical response to an isoleucine‐restricted diet was observed in both children.
In vivo study indicating loss of intracortical inhibition in tumor‐associated epilepsy
Authors: Irlbacher Kerstin , Brandt Stephan A. , Meyer Bernd‐Ulrich
Published: October 2002

Transcranial magnetic stimulation was performed in 2 patients with focal motor seizures in the right hand caused by a circumscribed tumor process affecting the left precentral gyrus. In both cases, paired‐pulse transcranial magnetic stimulation showed a loss of intracortical inhibition for interstimulus intervals of 2 to 4msec that was replaced by an enormous facilitation in the lesioned hand motor cortex. The uniform impairment of inhibitory mechanisms in epileptogenic tumors with different histologies suggests a common, nonspecific cause of tumor‐related epileptogenesis.
Sudomotor testing predicts the presence of neutralizing botulinum A toxin antibodies
Authors: Birklein Frank , Walther Dirk , Bigalke Hans , Winterholler Martin , Erbguth Frank
Published: October 2002

The increasing number of patients being treated with botulinum toxin A complex (BoNT/A) has led to a higher incidence of neutralizing anti‐BoNT/A antibodies (ABAs). Because BoNT/A is known to inhibit sweating, here we report sudometry as a possibility for predicting the presence of ABA. Sixteen patients suffering from spasmodic torticollis were selected: in 2 patients, BoNT/A treatment continued to be effective, in 9 patients, the treatment effect was impaired, and in 5 patients, secondary treatment failure developed. BoNT/A (100 mouse units, Dysport; Ipsen Pharma, Berkshire, United Kingdom) was injected subcutaneously into the lateral calves. Sweating was visualized with iodine starch staining. In addition, quantitative sudomotor axon reflex testing was performed at the injection site. Individual ABA titers were determined with a mouse bioassay. Results of sudometry significantly correlated with the BoNT/A treatment success. The quantitative sudomotor axon reflex testing was 0.58 ± 0.63 fraction of the normal mean in patients with treatment failure, 0.18 ± 0.13 fraction of the normal mean in those who responded partially, and 0 in responders (p < 0.01). Accordingly, the areas of the anhidrotic skin after subcutaneous injections were 4.5 ± 10.3cm2, 32.7 ± 16.5cm2, and 62cm2 (p < 0.01). Discrimination analysis indicated that the presence of ABA (6 ABA‐positive and 10 ABA‐negative) could be predicted correctly in all patients from the results of sudometry. Therefore, sudometry is a useful tool for identifying patients with neutralizing ABAs and might be helpful for identifying reasons for BoNT/A treatment failure.
Cofactors of mitochondrial enzymes attenuate copper‐induced death in vitro and in vivo
Authors: Sheline Christian T. , Choi Eric H. , Kim‐Han Jeong‐Sook , Dugan Laura L. , Choi Dennis W.
Published: October 2002

Copper toxicity contributes to neuronal death in Wilson's disease and has been speculatively linked to the pathogenesis of Alzheimer's and prion diseases. We examined copper‐induced neuronal death with the goal of developing neuroprotective strategies. Copper catalyzed an increase in hydroxyl radical generation in solution, and the addition of 20μM copper for 22 hours to murine neocortical cell cultures induced a decrease in ATP levels and neuronal death without glial death. This selective neuronal death was associated with activation of caspase‐3 and was reduced by free radical scavengers and Z‐Val‐Ala‐Asp fluoromethylketone, consistent with free radical–mediated injury leading to apoptosis. Pyruvate dehydrogenase is especially vulnerable to inhibition by oxygen free radicals, and the upstream metabolites, pyruvate, phosphoenolpyruvate, and 2‐phosphoglycerate were elevated in cortical cells after toxic exposure to copper. One approach to protecting pyruvate dehydrogenase from oxidative attack might be to enhance binding to cofactors. Addition of thiamine, dihydrolipoic acid, or pyruvate reduced copper‐induced neuronal death. To test efficacy in vivo, we added 1% thiamine to the drinking water of Long Evans Cinnamon rats, an animal model of Wilson's disease. This thiamine therapy markedly extended life span from 6.0 ± 1.6 months to greater than 16 months.
Electrical and mechanical characteristics of composites consisting of fractionated poly(3‐hexylthiophene) and conducting particles
Authors: Miyauchi Shinnosuke , Kondo Takamitsu , Oshima Kenji , Yamauchi Takeshi , Shimomura Masato , Mitomo Hiroshi
Published: October 2002

The dynamic viscoelasticity of fractionated poly(3‐ hexylthiophene)titanium carbide (P3HT/TiC) composites was examined with regard to their electrical characteristics. The elastic modulus (E′) at 0°C [i.e., near the glass‐transition temperature (Tg) of P3HT] increased with increasing TiC content of the composite. In particular, composites whose TiC content exceeded the threshold concentration showed a high E′. This was caused by the high E′ of TiC and the strong interaction between TiC and P3HT. When the sample was heated above the Tg, E′ decreased rapidly and an increase in the loss tangent appeared near the Tg of P3HT. Mechanical loss was caused by friction between TiC and P3HT. The change in mechanical characteristics affected the electrical conductivity. When the TiC content of the composite approximated to the threshold concentration, a significant change in mechanical characteristics took place, so that a large positive temperature coefficient (PTC) effect was observed near the Tg. To explain the PTC phenomenon, we propose a model of conductive pathway for P3HT/TiC. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1429– 1433, 2002
Polyion complex composite membranes for the separation of methyl t‐butyl ether/methanol mixtures: Separation behaviors of these membranes
Authors: Kim Sang‐Gyun , Kim Yong‐Il , Lim Gyun‐Taek , Jegal Jonggeon , Lee Kew‐Ho
Published: October 2002

For the pervaporation separation of methyl t‐butyl ether (MTBE)/methanol mixtures, polyion complex (PIC) composite membranes, composed of sodium alginate (SA) and chitosan, were prepared by alternating electrostatic adsorption of SA and chitosan on polysulfone‐supporting membrane. The pervaporation experiments were carried out under various preparation and operating conditions. The results showed that the prepared membranes strongly exhibited a methanol permselectivity for the MTBE/methanol mixtures, and moreover, through certain of these membranes, only methanol was permeated. Also, by increasing the chitosan content in the reaction solution, the permeation rates and MTBE concentrations in the permeate decreased gradually because of an increase in the ionic complexation between SA and chitosan. Furthermore, raising the pervaporation temperature led to an increase in both the permeation rate and the separation factor. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1832–1842, 2002
Pervaporation separation of water–ethanol mixtures using metal‐ion‐exchanged poly(vinyl alcohol) (PVA)/sulfosuccinic acid (SSA) membranes
Authors: Rhim Ji‐Won , Lee Sun‐Wha , Kim Youn‐Kook
Published: October 2002

Poly(vinyl alcohol)/sulfosuccinic acid (PVA/SSA) membranes in the hydrogen form were converted to monovalent metal ion forms Li+, Na+, and K+. The effect of exchange with metal ions was investigated by measuring the swelling of water–ethanol (10/90) mixtures at 30 °C and by the pervaporative dehydration performance test for aqueous ethanol solutions with various ethanol concentrations at 30, 40, and 50 °C. In addition, electron spectroscopy for chemical analysis (ESCA) analysis was carried out to study the quantity of metal ions in membranes. From the ESCA analysis, the lithium ion quantity in the resulting membranes is greater than that of any other metal ions in question because of the easy diffusion of a smaller metal ion into the membrane matrix. The swelling ratio was in the following order: PVA/SSA‐Li+ > PVA/SSA‐Na+ > PVA/SSA‐K+ membranes. For pervaporation, the PVA/SSA‐Na+ membrane showed the lowest flux and highest separation factor for all aqueous ethanol solutions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1867–1873, 2002
The use of polymers as sequestering agents for toxic metal ions
Authors: Eboatu A. N. , Diete‐Spiff S. T. , Ezenweke L. O. , Omalu F.
Published: October 2002

Polymer‐metal complexes were formed by nonsolvent precipitation technique for the metals Co, Pb, Ni, Cr, and Fe, and polystyrene (Pst), Poly(vinyl chloride) (PVC), and Nylon 66. By means of Fourier transform Infrared studies, it was established that chemical bonds actually do exist between the metal ions and the polymers (i.e., that the metal ions are not simply adsorbed on the surface of the polymers). It was observed also that the degrees of metal‐polymer interaction vary from polymer, from metal ion to metal ion, and depend on the metal ion concentration. These observations are explained in terms of the atomic radii and charges on the transition metal ions. The number and type of interaction sites/ligands on the substrates are also considered relevant. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2781–2786, 2002
Preparation and properties of conductive polyaniline/poly‐ω‐aminoundecanoyle fibers
Authors: Zhang Qinghua , Wang Xianhong , Chen Dajun , Jing Xiabin
Published: October 2002

Historically, polyaniline (PANI) had been considered an intractable material, but it can be dissolved in some solvents. Therefore, it could be processed into films or fibers. A process of preparing a blend of conductive fibers of PANI/poly‐ω‐aminoundecanoyle (PA11) is described in this paper. PANI in the emeraldine base was blended with PA11 in concentrated sulfuric acid (c‐H2SO4) to form a spinning dope solution. This solution was used to spin conductive PANI / PA11 fibers by wet‐spinning technology. As‐spun fibers were obtained by spinning the dopes into coagulation bath water or diluted acid and drawn fibers were obtained by drawing the as‐spun fibers in warm drawing bath water. A scanning electron microscope was employed to study the effect of the acid concentration in the coagulation bath on the microstructure of as‐spun fibers. The results showed that the coagulating rate of as‐spun fibers was reduced and the size of pore shrank with an increase in the acid concentration in the coagulation bath. The weight fraction of PANI in the dope solution also had an influence on the microstructure of as‐spun fibers. The microstructure of as‐spun fibers had an influence on the drawing process and on the mechanical properties of the drawn fibers. Meanwhile, the electrically conductive property of the drawn fibers with different percentage of PANI was measured. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1458–1464, 2002
Solid‐state nuclear magnetic resonance study of polyurethane/natural fibers composites
Authors: Tavares Maria Inês B. , Mothé Cheila G. , Araújo Carla R.
Published: October 2002

In the present study, fiber‐reinforced plastics (FRP) were prepared with sisal and the sugarcane waste material. The composites of these fibers with polyurethanes were obtained by processing these materials in a Haake plastograph, and their homogeneity was characterized by nuclear magnetic resonance (NMR) measurements. The results are discussed in terms of composites interaction, homogeneity, and compatibility. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1465–1468, 2002
Acoustic properties of nitrile butadiene rubber for underwater applications
Authors: Jung Kyung‐Il , Yoon Suk Wang , Cho Kuk Young , Park Jung‐Ki
Published: October 2002

Acoustic properties of nitrile butadiene rubber (NBR) specimens with carbon black as filler were investigated with different sulfur contents in the frequency range of 300‐1000 kHz. Their mechanical properties, such as density, hardness, tensile strength, were conventionally measured and correlated with their acoustic properties. Sound speeds in the specimens were increased with an increase in the sulfur content. The variation of sound speed was about 2–5% in the specimens, whereas the variation of density was less than 0.4%. Enhanced acoustic transmission was also observed with increasing sulfur content. It may be due to the hardness change from the increase of crosslinking density in the specimens. These results show that the mechanical properties of NBR can be nondestructively and accurately determined with the acoustic property measurements. By use of the desired mechanical and acoustic properties, the utilization of the NBR for underwater applications becomes less d
ficult. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2764–2771, 2002
Photosensitive barrier rib paste for plasma display panel and photolithographic process
Authors: Jeong Seung Won , Kim Woo Sik , Lee Dong Ho , Min Kyung Eun , Seo Kwan Ho , Kang Inn Kyu , Park Lee Soon
Published: October 2002

Barrier ribs in color plasma display panels (PDPs) function to maintain the discharge space between two glass plates as well as to prevent optical crosstalk. Patterning of barrier ribs is one of the unique processes for making PDPs. In this work, photosensitive barrier rib pastes were prepared by incorporating binder polymer, solvent, functional monomers, photoinitiator, and barrier rib powder. Studies of the function of the materials for the barrier rib paste were undertaken. After optimization of the paste formulation and photolithographic process, the barrier rib could be obtained with good resolution up to 110–120 μm height and 80–90 μm width. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2092–2099, 2002
Pervaporation separation of water‐isopropyl alcohol mixtures with blend membranes of sodium alginate and poly(acrylamide)‐grafted guar gum
Authors: Toti Udaya S. , Aminabhavi Tejraj M.
Published: October 2002

The blend membranes of sodium alginate (Na‐Alg) and poly(acrylamide)‐grafted guar gum (PAAm‐g‐GG) in the ratios of 3:1 and 1:1 were prepared and studied for the pervaporation separation of water–isopropyl alcohol mixtures over the entire range of mixture composition at 30°C. Membranes prepared from neat Na‐Alg (M‐1) and the 1:1 blend of Na‐Alg and PAAm‐g‐GG (M‐3) showed the highest separation selectivity for 10 mass % water in the feed mixture, whereas membranes prepared with the 3:1 blend ratio of Na‐Alg to PAAm‐g‐GG showed the highest separation selectivity of 20 mass % water in the feed. Selectivity decreased with increasing amount of water in the feed for all the membranes, but these values show an increase with increasing amount of grafted copolymer in the blend mixture. Flux increased with increasing amount of water in the mixture, but the flux values did not change markedly with the PAAm‐g‐GG content in the blend membrane at the lower mass % water. At higher mass % of water, the flux values of the blends increase systematically with increasing amount of PAAm‐g‐GG in the blend polymer. For the 10 mass %‐containing binary mixtures, the pervaporation separation experiments were performed at 30, 40, and 50°C, and the resulting data were used to calculate the Arrhenius activation parameters. These data indicated activated pore‐type diffusion of the permeants in the membranes. Dynamic sorption studies were also performed on up to 40 mass % water–isopropyl alcohol mixtures at 30°C. These results, when analyzed by the empirical equation, indicated Fickian transport in all the cases. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2014–2024, 2002
Synthesis and characterization of nonionic 1‐vinyl‐2‐pyrrolidinone/methacryloxy silicone copolymers: Effects of molecular weight of silicone and crosslinking density
Authors: Kim Jin‐Chul , Song Myung‐Eon , Park Seung‐Kyu , Lee Eun‐Joo , Rang Moon‐Jeong , Ahn Ho‐Jeong
Published: October 2002

Nonionic 1‐vinyl‐2‐pyrrolidinone/methacryloxy silicone copolymers (VP/VS copolymers) were prepared and characterized as functions of molecular weight of silicone and crosslinking density. Fourier transform infrared spectroscopy, 13C‐NMR, and pyrolysis gas chromatography–mass spectrometry study showed that those copolymers were successfully synthesized. Also, the gel‐permeation chromatography spectrum exhibited a fairly narrow distribution of the molecular weight of the polymer. It was found that the turbidity in ethanol (EtOH) and the glass‐transition temperature of crosslinked VP/VS copolymers are influenced by the amount of crosslinking agent. However, in the case of branched VP/VS copolymers, a transparent solution was obtained, regardless of the molecular weight of silicone. SEM/EDS study revealed that silicone is more abundant on the coating surface than on the interface of coating/glass. This is probably because Si‐containing chains have lower surface energy than that of vinylpyrrolidinone‐containing chains. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2244–2253, 2002
Polypropylene/metallocene ethylene‐octene copolymer blends with a bimodal particle size distribution: Mechanical properties and their controlling factors
Authors: Premphet K. , Paecharoenchai W.
Published: October 2002

Blends of polypropylene homopolymer (PP) and metallocene produced ethylene‐octene copolymer (EOR) with a bimodal particle size distribution were investigated. The aim of the work was to study the influences of EOR characteristics and its concentration on the tensile and impact properties of the blends. The matrix ligament thickness between rubber particles was measured and compared to those predicted using the theoretical models. The relationships between blend morphology and impact property were reported. It was found that the content of comonomer and molecular weight of the EOR as well as its concentration in the blends were the major factors controlling the tensile and impact properties of the blends. These factors became ineffective to impact property when the ligament thickness of the matrix was larger than the critical value (T ∼0.3–0.4 μm). To achieve blends of high impact strength, the ligament thickness between rubber particles should be smaller than the critical value, and for a certain ligament thickness, EOR with high octene content and high molecular weight was preferred. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2412–2418, 2002
Photopolymerization of N,N‐dimethylaminoethylmethacrylate studied by photocalorimetry
Authors: Pamedytytė V. , Abadie M. J. M. , Makuška R.
Published: October 2002

Photopolymerization of dimethylaminoethylmethacrylate (DMAEMA) is studied in bulk and in solutions in the presence of different photoinitiators using differential photocalorimetry (DPC). The rate of DMAEMA photopolymerization is slow compared to that of alkylmethacrylates. Bimodal DPC curves of DMAEMA photopolymerization in bulk are obtained. The type I photoinitiators (IRGACURE® 651 and IRGACURE® 1700), which produce free radicals by homolytic fragmentation of photoexcited molecules, are more effective in promoting photopolymerization of DMAEMA. The type II photoinitiators (benzophenone and IRGACURE® 500), which initiate DMAEMA photopolymerization through an H‐abstraction mechanism involving an amino group from the monomer (polymer), are less efficient and favor the formation of partly crosslinked products. The effects of the photoinitiator concentration, temperature, and solvent on the kinetic data are evaluated and discussed. A scheme of photopolymerization of DMAEMA, including the formation of intermediate DMAEMA based macromonomers, is proposed. The main point of the suggested scheme is a high chain transfer to the DMAEMA monomer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 579–588, 2002
Polymer distribution during bicomponent melt blowing of poly(propylene)/poly(ethylene terephthalate) and its improvement
Authors: Zhao Ron (Rongguo) , Wadsworth Larry C. , Zhang Dong , Sun Christine
Published: October 2002

Bicomponent melt blown (MB) microfiber nonwovens of poly(propylene) (PP) and poly(ethylene terephthalate) (PET) were produced in this study. It is interesting to analyze the polymer distribution uniformity across the web because it affects many end‐use properties. By utilizing the technique of differential scanning calorimetry (DSC), a standard working line between heat of fusion and weight percentage was constructed for mixtures of PP and PET components. The fitted equations were used for determination of a component percentage in a certain position across the MB web. Measurements were conducted from DSC re‐heating curves to achieve accurate results. The distribution of polymer varies with polymer mass ratio and processing conditions. The overall uniformity increased with the percentage of PP. When PP is the minor component in the polymer pair, it exhibits notably higher percentage in edge areas across the MB web. These results suggest the phase interface distortion of the polymer melt occurred at the entrance of the MB coat‐hanger die tip. The polymer distribution uniformity is improved by adjusting temperature profile of the MB die. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2885–2889, 2002
Whole‐genome linkage analysis of rheumatoid arthritis susceptibility loci in 252 affected sibling pairs in the United Kingdom
Authors: MacKay Kirsten , Eyre Stephen , Myerscough Anne , Milicic Anita , Barton Anne , Laval Steven , Barrett Jenny , Lee Dorothea , White Sarah , John Sally , Brown Matthew A. , Bell John , Silman Alan , Ollier William , Wordsworth Paul , Worthington Jane
Published: October 2002

Objective

To undertake a systematic whole‐genome screen to identify regions exhibiting genetic linkage to rheumatoid arthritis (RA).

Methods

Two hundred fifty‐two RA‐affected sibling pairs from 182 UK families were genotyped using 365 highly informative microsatellite markers. Microsatellite genotyping was performed using fluorescent polymerase chain reaction primers and semiautomated DNA sequencing technology. Linkage analysis was undertaken using MAPMAKER/SIBS for single‐point and multipoint analysis.

Results

Significant linkage (maximum logarithm of odds score 4.7 [P = 0.000003] at marker D6S276, 1 cM from HLA–DRB1) was identified around the major histocompatibility complex (MHC) region on chromosome 6. Suggestive linkage (P < 7.4 × 10−4) was identified on chromosome 6q by single‐ and multipoint analysis. Ten other sites of nominal linkage (P < 0.05) were identified on chromosomes 3p, 4q, 7p, 2 regions of 10q, 2 regions of 14q, 16p, 21q, and Xq by single‐point analysis and on 3 sites (1q, 14q, and 14q) by multipoint analysis.

Conclusion

Linkage to the MHC region was confirmed. Eleven non‐HLA regions demonstrated evidence of suggestive or nominal linkage, but none reached the genome‐wide threshold for significant linkage (P = 2.2 × 10−5). Results of previous genome screens have suggested that 6 of these regions may be involved in RA susceptibility.
Autoantibody to hLSm4 and the heptameric LSm complex in anti‐Sm sera
Authors: Eystathioy Theophany , Peebles Carol L. , Hamel John C. , Vaughn John H. , Chan Edward K. L.
Published: October 2002

Objective

To characterize the 15‐kd human SmD‐like autoantigen and its associated proteins previously shown to be recognized by IgM antibodies in patients with Epstein‐Barr virus (EBV)‐induced infectious mononucleosis.

Methods

The full‐length complementary DNA for the 15‐kd protein was expressed as recombinant protein and analyzed for reactivity using biochemical analysis and immunoprecipitation (IP).

Results

The 15‐kd protein was determined to be the human like‐Sm protein LSm4 (hLSm4). Rabbit antibody raised against the C‐terminal polypeptide immunoprecipitated a 68‐kd complex composed of LSm4 together with a group of smaller proteins ranging in size from 6.5 to 14 kd, consistent with the reported heptameric LSm complexes involved in U4/U6 duplex formation and messenger RNA (mRNA) decapping/degradation. About 80% of all anti‐Sm sera from patients with systemic lupus erythematosus (SLE) recognized the hLSm4 in vitro translated product, while 6.7% (29 of 434) immunoprecipitated from cell extracts hLSm4 together with the other members of the hLSm complex. Four sera (0.92%) showed apparently exclusive reactivity to the hLSm complex in the absence of reactivity to Sm core proteins in the IP assay.

Conclusion

These findings document that while IgM, but not IgG, autoantibodies to LSm4 were found in sera from patients with EBV infection, IgG autoantibodies to hLSm4 are detected in a large number of anti‐Sm‐positive sera from patients with SLE. Importantly, in a small number of anti‐Sm sera the LSm complex can be recognized independently of the Sm core protein antigens. Our data introduce the concept that “Sm” autoantigens include Sm as well as LSm complexes involved in the maturation and degradation of mRNA.