bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional, comparative and cell biological analysis of Saccharomyces cerevisiae Kre5p
Authors: Levinson Joshua N. , Shahinian Serge , Sdicu Anne‐Marie , Tessier Daniel C. , Bussey Howard 
Published: October 2002

AbstractSaccharomyces cerevisiae kre5Δ mutants lack β‐1,6‐glucan, a polymer required for proper cell wall assembly and architecture. A functional and cell biological analysis of Kre5p was conducted to further elucidate the role of this diverged protein glucosyltransferase‐like protein in β‐1,6‐glucan synthesis. Kre5p was found to be a primarily soluble N‐glycoprotein of ∼200 kDa, that localizes to the endoplasmic reticulum. The terminal phenotype of Kre5p‐deficient cells was observed, and revealed a severe cell wall morphological defect. KRE6, encoding a glucanase‐like protein, was identified as a multicopy suppressor of a temperature‐sensitive kre5 allele, suggesting that these proteins may participate in a common β‐1,6‐biosynthetic pathway. An analysis of truncated versions of Kre5p indicated that all major regions of the protein are required for viability. Finally, Candida albicans KRE5 was shown to partially restore growth to S. cerevisiae kre5Δ cells, suggesting that these proteins are functionally related. Copyright © 2002 John Wiley & Sons, Ltd.
Functional analysis of yeast gene families involved in metabolism of vitamins B1 and B6
Authors: Rodríguez‐Navarro Susana , Llorente Bertrand , Rodríguez‐Manzaneque María Teresa , Ramne Anna , Uber Genoveva , Marchesan Denis , Dujon Bernard , Herrero Enrique , Sunnerhagen Per , Pérez‐Ortín José E. 
Published: October 2002

AbstractIn order to clarify their physiological functions, we have undertaken a characterization of the three‐membered gene families SNZ1–3 and SNO1–3. In media lacking vitamin B6, SNZ1 and SNO1 were both required for growth in certain conditions, but neither SNZ2, SNZ3, SNO2 nor SNO3 were required. Copies 2 and 3 of the gene products have, in spite of their extremely close sequence similarity, slightly different functions in the cell. We have also found that copies 2 and 3 are activated by the lack of thiamine and that the Snz proteins physically interact with the thiamine biosynthesis Thi5 protein family. Whereas copy 1 is required for conditions in which B6 is essential for growth, copies 2 and 3 seem more related with B1 biosynthesis during the exponential phase. Copyright © 2002 John Wiley & Sons, Ltd.
Pyruvate dehydrogenase specific T cells in primary biliary cirrhosis show restricted antigen recognition sites
Authors: Pingel Sabine , Arenz Monika , Meyer zum Büschenfelde Karl‐Hermann , Löhr Hanns F. 
Published: October 2002

Abstract:  Background/Aims: The aim was to characterise the antigen recognition sites of the variable T cell receptor α‐chain (TCRAV) and β‐chain (TCRBV) of T cells specific to the pyruvate dehydrogenase (PDC) in primary biliary cirrhosis.Methods: In 21 PDC‐specific T cell clones isolated from five patients we analysed TCRAV and TCRBV usage by RT‐PCR and sequenced the CDR3 regions.Results: Preferential expression of the TCR elements BV6 (6 clones), BV12 (4 clones) and BV1 (3 clones), and frequent usage of the joining elements JB2.3 and JB2.1 were seen. Analysis of the α chain revealed rearrangement of AV2 in 7 clones (35%) and AV7 in 3 clones, however, distribution of the joining elements was heterogenous and no common sequence motifs were detected. Evaluation of the physicochemical properties of the β‐chain demonstrated a positive charge at position P4 in several clones of two patients and a hydrophobic residue at position P5 in two different patients. Further, a conserved glycine at position P7 and neutral residues at positions P6 and P8 were frequently detected.Conclusions: Our data define TCR variable region restriction and preferred CDR3 features of PDC‐specific T cells and support the notion that few relevant epitopes on the PDC complex are recognised by selected T cells.
Collagen sandwich culture affects intracellular polyamine levels of human hepatocytes
Authors: Weiss T. S. , Jahn B. , Cetto M. , Jauch K.‐W. , Thasler W. E. 
Published: October 2002

Abstract. Extracellular matrices, like collagen layers, play an important role in preventing dedifferentiation of hepatocytes in long‐term culture experiments. It has also been shown that polyamines are crucial for cell growth and liver differentiation – regeneration. Primary cultured hepatocytes with their low mitotic activity might be a valuable tool in studying the role of polyamines in differentiation. Here, our goal was to investigate whether an extracellular cell culture matrix can influence intracellular polyamine levels in human hepatocytes during long‐term culture. Primary human hepatocytes were isolated from surgical tissue resections and were maintained either in single collagen (SG) or double collagen gel (DG) layer (sandwich) culture systems. Cell viability and function were examined and intracellular polyamine levels were measured using a highly sensitive high performance liquid chromatography (HPLC) method. Hepatocytes showed high viability in both culture systems used, but albumin secretion was diminished in SG cultured hepatocytes after 14 days. In general, total intracellular polyamine levels of hepatocytes decreased markedly in both SG and DG within the first days of culture, but remained constant until day 21 with a SG/DG ratio of about 1.4. Individual polyamines levels were dependent on the culture time and system, where spermine decreased and putrescine increased in both SG and DG over time (day 14), but spermidine increased only in DG. Our results suggest that polyamine levels, in particular putrescine, might be important regulators of hepatocyte specific function in vitro and therefore serve as a marker of differentiation for cultivated human hepatocytes.
Total and allergen‐specific immunoglobulin A levels in saliva in relation to the development of allergy in infants up to 2 years of age
Authors: Böttcher M. F. , Häggström P. , Björkstén B. , Jenmalm M. C. 
Published: October 2002

SummaryBackground The association between salivary IgA levels and development of allergy is controversial and the employed methodology has been questioned.Objective The aim of the study was to relate the levels of total IgA, SIgA and allergen‐specific IgA antibodies in saliva to the development of allergy in infants during the first 2 years of life.Methods Saliva samples from 80 infants participating in a prospective study regarding the development of allergy were collected at 3 or 6, and 12 and 24 months of age. Total IgA, SIgA and Fel d 1 and β‐lactoglobulin specific IgA levels were analysed with ELISA.Results The levels of total IgA and SIgA increased with age. The number of samples with detectable IgA to Fel d 1 tended to increase with age, whereas the opposite was observed for IgA to β‐lactoglobulin. Infants who developed allergy tended to have higher levels of total IgA, and allergen‐specific IgA was more commonly detected than in non‐allergic children. In contrast, non‐allergic children tended to have higher levels of SIgA. Furthermore, the levels of SIgA were higher in sensitized infants with no allergic symptoms than in sensitized children with symptoms. Infants with allergic parents had lower SIgA levels than infants without. Direct exposure to cat and cow's milk did not influence the levels of allergen‐specific IgA levels, nor was there any association between breast‐feeding and IgA production.Conclusion The kinetics of food and inhalant allergen‐specific IgA in saliva during the first 2 years of life is similar to what has earlier been shown for IgG in serum. Development of allergy tended to be associated with high levels of total and allergen‐specific IgA antibodies, but low levels of SIgA. Furthermore, high levels of SIgA seemed to protect sensitized children from developing allergic symptoms during the first 2 years of life, supporting a possible protective role of SIgA against development of allergy.
Clinical and immunologic factors associated with the presence or absence of airways hyper‐responsiveness in childhood asthma
Authors: Visser M. J. , Brand P. L. P. , Boezen H. M. , Van Aalderen W. M. C. , Kauffman H. F. , Postma D. S. 
Published: October 2002

SummaryBackground During the baseline period of a clinical trial comparing different dosage schedules of inhaled steroids, asthmatic children (aged 6–10 years) were expected to meet the inclusion criterion of airways hyper‐responsiveness (PD20 methacholine < 80 µg) after withdrawal of inhaled corticosteroids for 2–8 weeks. However, many children failed to do so.Objective It has been shown that young wheezing children may outgrow their symptoms. We investigated if differences between children with and without airways hyper‐responsiveness after withdrawal of inhaled corticosteroids were compatible with differences between transient and persistent wheezers found in other studies.Methods Seventy‐eight children entered the study, of which 41 developed airways hyper‐ responsiveness after withdrawal of inhaled corticosteroids, and 37 did not. These two groups of children were compared with respect to differences in demographic, clinical, and immunological features (IL‐4, IL‐5, IL‐10, and IFN‐γ produced by Con A stimulated peripheral mononuclear cells (PBMCs) and serum IL‐4, IL‐5 and soluble intercellular adhesion molecule‐1 (sICAM‐1)).Results Hyper‐responsive children had more atopic features (positive RAST, high IgE, eczema), lower levels of FEV1 and lower concentrations of sICAM‐1 than non‐hyper‐responsive children. Apart from a borderline significantly higher IL‐4 production in the hyper‐responsive group, other immunologic parameters were comparable. Multivariate logistic regression analysis showed that high serum IgE, low FEV1, and low sICAM‐1 levels were independently associated with the presence of airways hyper‐responsiveness after stopping inhaled corticosteroids. Atopy was associated with higher concentrations of IL‐4 in the hyper‐responsive group.Conclusion After withdrawal of inhaled corticosteroids many children previously diagnosed with asthma did not develop airways hyper‐responsiveness. We conclude that hyper‐responsive children share features with persistent wheezers as found in previous studies, whereas the non‐hyper‐ responsive children may represent transient wheezers.
Renal and vascular effects of S21402, a dual inhibitor of angiotensin‐converting enzyme and neutral endopeptidase, in healthy subjects with hypovolemia
Authors: Chodjania Yasmina , Tharaux Pierre‐Louis , Ragueneau Isabelle , Dussaule Jean‐Claude , Picker Jean‐Luc , Funck‐Brentano Christian , Jaillon Patrice 
Published: October 2002

ObjectiveTo examine the mechanism of action of dual inhibitors of angiotensin‐converting enzyme (ACE) and neutral endopeptidase, also called vasopeptidase inhibitors, we compared the effects of S21402 [(2S)‐2‐{(2S,3R)‐2‐thiomethyl‐3‐phenylbutanamido}propionic acid], which belongs to this pharmacologic class, with those of captopril, an ACE inhibitor, on blood pressure, endocrine parameters, and renal in healthy subjects with hypovolemia.MethodsTen subjects participated to this double‐blind, 2‐period, randomized, crossover study. Hypovolemia was induced in these subjects with a 7‐day treatment of hydrochlorothiazide. They received a single oral dose of 50 mg captopril or 250 mg S21402 on the last day of diuretic treatment. Blood pressure was measured, and urine and blood samples were collected before and during a 12‐hour period after drug administration.ResultsThe plasma angiotensin II/angiotensin I ratio and aldosterone concentration decreased to the same degree with both drugs, 3 hours after dosing. Compared with captopril, S21402 increased levels of plasma atrial natriuretic peptide (P < .05) and urinary cyclic guanosine monophosphate (P < .001); these increases were the result of inhibition of neutral endopeptidase activity (P < .001). The increase in plasma renin concentration related to ACE inhibition was less marked (P < .001) after S21402 than after captopril. S21402, but not captopril, increased urinary sodium excretion (P < .05), without modifying blood pressure and creatinine clearance, whereas blood pressure transiently fell after ceptopril administration (P < .05).ConclusionsIn healthy hypovolemic subjects, the vasopeptidase inhibitor S21402 exhibits a natriuretic effect and does not affect blood pressure or glomerular filtration rate. In these conditions, the acute endocrine, vascular, and renal effects of vasopeptidase inhibition differ from those of ACE inhibition.Clinical Pharmacology & Therapeutics (2002) 71, 468–478; doi: 10.1067/mcp.2002.124521
Angiotensin II attenuates the vasodilating effect of a nitric oxide donor, glyceryl trinitrate: Roles of superoxide and angiotensin II type 1 receptors
Authors: Wada Atsushi , Ueda Shinichiro , Masumori‐Maemoto Satoko , Kuji Naomitsu , Sugimoto Koh‐ichi , Umemura Satoshi 
Published: October 2002

ObjectiveThe development of tolerance to organic nitrates limits their usefulness in the treatment of heart disease. Activation of the renin‐angiotensin system by heart failure itself and by nitrate therapy may be one possible mechanism underlying nitrate tolerance. We investigated the effect of subpressor doses of angiotensin II on the vasodilating effect of glyceryl trinitrate in human forearm resistance vessels of healthy male subjects by using venous occlusion strain‐gauge plethysmography.MethodsGlyceryl trinitrate was infused intra‐arterially with angiotensin II or vehicle. The effect of blockade of angiotensin II type 1 receptors by candesartan or an antioxidant, vitamin C, on the interaction between angiotensin II and glyceryl trinitrate was also investigated.ResultsAngiotensin II infused at 5 pmol/min significantly attenuated the vasodilating effect of glyceryl trinitrate (mean ± standard deviation [SD] of percentage change in forearm blood flow [FBF]: 28% ± 20%, 79% ± 59%, and 208% ± 72% at 100, 250, and 1000 ng/min of glyceryl trinitrate with placebo; 8% ± 18%, 47% ± 41%, and 173% ± 98% with angiotensin II at 1 pmol/min; and 2% ± 27%, 39% ± 40%, and 132% ± 74% with angiotension II at 5 pmo;/min; P = .0259). Either a single dose of candesartan or coinfusion with vitamin C abolished the angiotensin II‐induced attenuation of vasodilation of glyceryl trinitrate.ConclusionOur results suggest that angiotensin II may attenuate the arterial vasodilating effect of glyceryl trinitrate through angiotensin type 1 receptors and presumably through receptor‐mediated superoxide production, which may be relevant to the development of nitrate tolerance.Clinical Pharmacology & Therapeutics (2002) 71, 440–447; doi: 10.1067/mcp.2002.125293
Plastic energy dissipation during compressive deformation of individual polymer pellets and polymer particulate assemblies
Authors: Gogos Costas G. , Qian Bainian 
Published: October 2002

AbstractPlastic energy dissipation (PED) of individual polymer pellets as well as of densified polymer particulate assemblies may be the dominant heating/melting mechanisms in intermeshing corotating twin‐screw extruders (Co‐TSEs). In the present paper, the amount of PED is evaluated by conducting the uniaxial unconfined compression experiments on both molded cylindrical polymer samples and polymer particulate assemblies. The compression experiments were extended to a much higher deformation (strain) range. The results of this work clearly demonstrate the significant contribution to melting from even a single deformation of individual pellets. One severe deformation of PP pellets can provide almost one sixth of the energy required for their melting. For PS pellets, one severe deformation alone can provide sufficient energy to heat up the pellets to above their glass‐transition temperature. On the other hand, the mechanical energy input during the compressive deformation of particulate assemblies is much lower than that of solid polymer samples, depending, to a great extent, on the degree of the particulate densification/void ratio of the particulate system. There are two types of PED in the melting section of Co‐TSEs, localized PED of individual pellets in the partially filled kneading section and global PED of consolidated particulate assemblies in the fully filled section. The mandatory deformation of solid particulates, caused by the interaction of kneading paddle pairs, and the associated PED for both individual pellets and consolidated particulate assemblies, provides very efficient heating/melting of polymer feedstock in Co‐TSEs. © 2002 Wiley Periodicals, Inc. Adv Polym Techn 21: 287–298, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.10033
Pigmentary mosaicism of the hyperpigmented type in two half‐brothers
Authors: Horn Denise , Happle Rudolf , Neitzel Heidemarie , Kunze Jürgen 
Published: October 2002

AbstractPigmentary mosaicism is a heterogeneous cutaneous phenotype that is often associated with extracutaneous anomalies. It is widely accepted that these phenotypes arise de novo as a result of a postzygotic mutation, leading to a mosaic status of the embryo. In the vast majority of cases, the occurrence of pigmentary mosaicism is sporadic. We report two paternal half‐brothers affected with pigmentary mosaicism of the hyperpigmented type. The hyperpigmentation in both patients is distributed along the lines of Blaschko. In addition, mental retardation, facial asymmetry, short stature, scoliosis, and short fingers with clinodactyly of the 5th digit were noted in one of them. Chromosome analysis in this 15‐year‐old patient demonstrated a mosaic 46,XY,dup(3)(p21.3;pter)/46,XY with 12% aberrant cells in lymphocytes and 2% in skin fibroblasts derived from a hyperpigmented area. His nine‐year‐old half‐brother had similar systematized hyperpigmented skin lesions, macrocephaly, facial asymmetry, and clinodactyly of the 5th digit. Chromosome analysis of peripheral lymphocytes showed a normal karyotype 46,XY. A skin biopsy could not be obtained. So far, some familial cases of hypopigmentation along the lines of Blaschko have been reported, but familial occurrence of the hyperpigmented type of pigmentary mosaicism appears to be extremely unusual. It is difficult to establish a causal relationship with the chromosomal mosaicism as observed in patient 1. Paradominant transmission seems unlikely because this would likewise imply that the chromosomal mosaicism is an incidental finding. © 2002 Wiley‐Liss, Inc.
Progressive vertebral fusion of unknown etiology: A case report
Authors: Farrior Jennifer H. , Weaver David D. , Kling Thomas F. , Klatte Eugene 
Published: October 2002

AbstractWe report a 16‐year‐old male with progressive vertebral fusion of the cervical, thoracic, and lumbar vertebrae; irregular vertebral body surfaces; coronal clefting of the vertebral bodies of the thoracic and lumbar spine; absence of one cervical vertebra; and a few other minor, nonspinous abnormalities. All laboratory findings have been within normal limits. To our knowledge, the particular findings in this patient have not been reported previously. © 2002 Wiley‐Liss, Inc.
Prenatal growth deficiency with narrowness of the cervical spine, subglottic stenosis, hip dislocation, and severe delayed bone ossification: A new skeletal dysplasia
Authors: Mégarbané André , Ghanem Ismat , Rizk Tony , Jabbour Pascal 
Published: October 2002

AbstractA boy with a severe prenatal onset dysplasia, prominent occiput, hypertelorism, epicanthus inversus, low‐set ears, flat nasal bridge, small nares, cleft palate, subglottic stenosis, narrow cervical canal, undermodeled bones, cortical thinning of the diaphyses, hip dislocation, severely delayed bone ossification, and apparently normal intellectual development is described. Osseous histopathological studies were unremarkable. The boy's parents are first cousins, suggesting recessive inheritance. To the best of our knowledge, this association has not been reported before, and may be considered a novel syndrome. © 2002 Wiley‐Liss, Inc.
Polydactyly: How many disorders and how many genes?
Authors: Biesecker Leslie G. 
Published: October 2002

AbstractDisorders that include polydactyly as a manifestation are diverse and numerous. Cataloging these disorders by phenotype and genotype demonstrates numerous overlapping phenotypes, genetic heterogeneity of phenotypes, and distinct phenotypes generated from mutations in single genes. To assess these issues, a list of disorders with polydactyly has been compiled from several sources. Among 119 disorders, 39 disorders are associated with mutations in genes, and among these, genotypic and phenotypic overlap is demonstrated. These issues highlight the need for a diagnostic system that catalogs both genotype and phenotype. Published 2002 Wiley‐Liss, Inc.
Interictal high‐frequency oscillations (80–500Hz) in the human epileptic brain: Entorhinal cortex
Authors: Bragin Anatol , Wilson Charles L. , Staba Richard J. , Reddick Mark , Fried Itzhak , Engel Jerome 
Published: October 2002

AbstractUnique high‐frequency oscillations of 250 to 500Hz, termed fast ripples, have been identified in seizure‐generating limbic areas in rats made epileptic by intrahippocampal injection of kainic acid, and in patients with mesial temporal lobe epilepsy. In the rat, fast ripples clearly are generated by a different neuronal population than normally occurring endogenous ripple oscillations (100–200Hz), but this distinction has not been previously evaluated in humans. The characteristics of oscillations in the ripple and fast ripple frequency bands were compared in the entorhinal cortex of patients with mesial temporal lobe epilepsy using local field potential and unit recordings from chronically implanted bundles of eight microelectrodes with tips spaced 500μm apart. The results showed that ripple oscillations possessed different voltage versus depth profiles compared with fast ripple oscillations. Fast ripple oscillations usually demonstrated a reversal of polarity in the middle layers of entorhinal cortex, whereas ripple oscillations rarely showed reversals across entorhinal cortex layers. There was no significant difference in the amplitude distributions of ripple and fast ripple oscillations. Furthermore, multiunit synchronization was significantly increased during fast ripple oscillations compared with ripple oscillations (p < 0.001). These data recorded from the mesial temporal lobe of epileptic patients suggest that the cellular networks underlying fast ripple generation are more localized than those involved in the generation of normally occurring ripple oscillations. Results from this study are consistent with previous studies in the intrahippocampal kainic acid rat model of chronic epilepsy that provide evidence supporting the view that fast ripples in the human brain reflect localized pathological events related to epileptogenesis.