bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of Local Immunoglobulin E Production in the Pathophysiology of Noninvasive Fungal Sinusitis
Authors: Collins Melanie , Nair Salil , Smith William , Kette Frank , Gillis David , Wormald Peter John 
Published: June 2004

AbstractObjectives/Hypothesis: Immunoglobulin (Ig)E‐mediated hypersensitivity to fungi has been postulated to explain allergic fungal sinusitis (AFS). Not all patients suspected to have AFS demonstrate systemic evidence of allergy. Locally produced IgE might explain those patients with no systemic evidence of allergy but clinical features of AFS. The aim was to determine whether fungal‐specific IgE could be demonstrated in sinus mucin in patients with eosinophilic mucin rhino‐sinusitis.Study Design: A prospective study was undertaken in a tertiary rhinology practice in Adelaide, South Australia.Methods: Eighty‐six consecutive patients with nasal polyposis and thick, colored macroscopically “fungal‐like” sinus mucin at time of surgery for chronic sinusitis were entered in the study. The sinus mucin was liquefied and underwent testing for fungal‐specific IgE (Pharmacia UniCAP) and fungal culture. Serum fungal‐specific and total IgE, eosinophil count, C‐reactive protein (CRP), and eosinophilic cationic protein (ECP) were measured.Results: Fifty‐six (65%) patients were fungal culture positive, and 37% had a detectable fungal‐specific IgE in sinus mucin. Data were available to classify 81 patients: AFS = 24 (30%), AFS‐like = 6 (7%), nonallergic eosinophilic fungal sinusitis = 32 (40%), nonallergic, nonfungal eosinophilic sinusitis = 19 (23%). Patients with AFS were significantly more likely to have fungal‐specific IgE in sinus mucin (17/24, 71%, P = .02). In all fungal culture‐positive patients, positive mucin fungal‐specific IgE was significantly associated with systemic fungal allergy (P = .005), but a raised total serum IgE was not. Six (19%) of the 32 patients with positive fungal cultures but negative serum fungal‐specific IgE had a positive mucin fungal‐specific IgE, suggesting that they may be reclassified as AFS. The mean ECP and total IgE were raised most significantly in the AFS subgroup.Conclusions: This is the first study to show that fungal‐specific IgE may be demonstrated in sinus mucin. It was significantly associated with systemic fungal allergy and may play a role in a minority of fungal sinusitis patients in the absence of systemic fungal allergy.
Structural alignment of proteins by a novel TOPOFIT method, as a superimposition of common volumes at a topomax point
Authors: Ilyin Valentin A. , Abyzov Alexej , Leslin Chesley M. 
Published: June 2004

AbstractSimilarity of protein structures has been analyzed using three‐dimensional Delaunay triangulation patterns derived from the backbone representation. It has been found that structurally related proteins have a common spatial invariant part, a set of tetrahedrons, mathematically described as a common spatial subgraph volume of the three‐dimensional contact graph derived from Delaunay tessellation (DT). Based on this property of protein structures, we present a novel common volume superimposition (TOPOFIT) method to produce structural alignments. Structural alignments usually evaluated by a number of equivalent (aligned) positions (Ne) with corresponding root mean square deviation (RMSD). The superimposition of the DT patterns allows one to uniquely identify a maximal common number of equivalent residues in the structural alignment. In other words, TOPOFIT identifies a feature point on the RMSD Ne curve, a topomax point, until which the topologies of two structures correspond to each other, including backbone and interresidue contacts, whereas the growing number of mismatches between the DT patterns occurs at larger RMSD (Ne) after the topomax point. It has been found that the topomax point is present in all alignments from different protein structural classes; therefore, the TOPOFIT method identifies common, invariant structural parts between proteins. The alignments produced by the TOPOFIT method have a good correlation with alignments produced by other current methods. This novel method opens new opportunities for the comparative analysis of protein structures and for more detailed studies on understanding the molecular principles of tertiary structure organization and functionality. The TOPOFIT method also helps to detect conformational changes, topological differences in variable parts, which are particularly important for studies of variations in active/ binding sites and protein classification.
Solubilization and delivery by GroEL of megadalton complexes of the λ holin
Authors: Deaton John , Savva Christos G. , Sun Jingchuan , Holzenburg Andreas , Berry Joel , Young Ry 
Published: June 2004

AbstractGroEL can solubilize membrane proteins by binding them in its hydrophobic cavity when detergent is removed by dialysis. The best‐studied example is bacteriorhodopsin, which can bind in the GroEL chaperonin at two molecules per tetradecamer. Applying this approach to the holin and antiholin proteins of phage λ, we find that both proteins are solubilized by GroEL, in an ATP‐sensitive mode, but to vastly different extents. The antiholin product, S107, saturates the chaperonin at six molecules per tetradecameric complex, whereas the holin, S105, which is missing the two N‐terminal residues of S107, forms a hyper‐solubilization complex with up to 350 holin molecules per GroEL, or approximately 4 MDa of protein per 0.8 MDa tetradecamer. Gel filtration chromatography and immunoprecipitation experiments confirmed the existence of complexes of the predicted masses for both S105 and S107 solubilization. For S105, negatively stained electron microscopic images show structures consistent with protein shells of the holin assembled around the chaperonin tetradecamer. Importantly, S105 can be delivered rapidly and efficiently to artificial liposomes from these complexes. In these delivery experiments, the holin exhibits efficient membrane‐permeabilizing activity. The S107 antiholin can block formation of the hypersolubilization complexes, suggesting that their formation is related to an oligomerization step intrinsic to holin function.
Behind the Numbers: Talking Politics with Foreign‐born Chinese Americans
Authors: Lien Pei‐te 
Published: June 2004

AbstractThis paper discusses results of in‐depth follow‐up interviews conducted with selected individuals of Chinese descent residing in Los Angeles and San Francisco who were previously chosen at random to participate in the 2000 and 2001 Pilot National Asian American Political Survey. A total of 15 male and female informants who had migrated from Taiwan, mainland China, and Hong Kong were interviewed in Mandarin Chinese. They were asked to compare the performance of the US Government with that of the government in their respective ethnic homeland. They were also asked to explain their reasons for supporting a certain US political party, ideology, and type of candidate. In addition, they commented on the state of political participation or the lack of it among Chinese Americans. Finally, they explained the complexity of their ethnic self‐identification and experiences of racial discrimination. Their responses were interpreted within the context of the historical formation of the Chinese American community as well as the summary results of the mass opinion survey. The results help dispel myths about Chinese Americans being politically indifferent and irrational. They help illuminate the possible relationships among ethnic identity, homeland politics, and political participation in the host land. They also provide exciting insights into improving the survey instrument for a majority immigrant and non‐Anglophone population.
Phylogeny of Australasian venomous snakes (Colubroidea, Elapidae, Hydrophiinae) based on phenotypic and molecular evidence
Authors: Scanlon John D. , Lee Michael S. Y. 
Published: June 2004

Scanlon, John D. & Lee, Michael S. Y. (2004). Phylogeny of Australasian venomous snakes (Colubroidea, Elapidae, Hydrophiinae) based on phenotypic and molecular evidence. — Zoologica Scripta, 33, 335–366.Phylogenetic relationships among Hydrophiinae (Australasian and marine elapid snakes) are inferred using 87 characters from external, skeletal, hemipenial and internal anatomy, ecology, and chromosomes as well as available sequences of two mitochondrial genes (cytochrome b and 16S rRNA). Parsimony analysis of the combined data retrieves many widely accepted clades; while observed bootstrap or branch (Bremer) support for these is often weak, most have never been corroborated previously by a rigorous numerical analysis. Sea kraits (Laticauda) and Solomon Islands elapids are basal to the remaining hydrophiines (Australian terrestrial forms and hydrophiin sea snakes). The latter clade includes three main lineages: a large‐bodied oviparous lineage, a small‐bodied oviparous lineage, and a viviparous lineage (which also includes the hydrophiin sea snakes, strongly reaffirmed as monophyletic). While the Solomons retain a relictual fauna, New Guinea has less endemism and has been invaded multiple times by Australian lineages, so there is no clear ‘stepping stone’ pattern supporting a northern (Asian, rather than Gondwanan) biogeographical origin.
Phylogeny of Recent Canidae (Mammalia, Carnivora): relative reliability and utility of morphological and molecular datasets
Authors: Zrzavý Jan , ŘIčánková Věra 
Published: June 2004

Zrzavý, J. & Řičánková, V. (2004). Phylogeny of Recent Canidae (Mammalia, Carnivora): relative reliability and utility of morphological and molecular datasets. — Zoologica Scripta, 33, 311–333.Phylogenetic relationships within the Canidae are examined, based on three genes (cytb, COI, COII) and 188 morphological, developmental, behavioural and cytogenetic characters. Both separate and combined phylogenetic analyses were performed. To inspect the phylogenetic ‘behaviour’ of individual taxa, basic phylogenetic analysis was followed by experimental cladistic analyses based on different data‐partition combinations and taxon‐removal analyses. The following phylogeny of the Recent Canidae is preferred: (1) Urocyon is the most basal canid; (2) Vulpes is a monophyletic genus (including Fennecus and Alopex); (3) the doglike canids (DC) form a clade (=Dusicyon + Pseudalopex + Lycalopex + Cerdocyon + Atelocynus + Chrysocyon + Speothos + Lycaon + Cuon + Canis), split into two subclades, South American and Afro‐Holarctic, with uncertain position of the Chrysocyon + Speothos subclade; (4) Canis is paraphyletic due to the position of Lycaon and Cuon. Otocyon and Nyctereutes are the most problematic canid genera, causing an unresolved branching pattern of Otocyon, Vulpes, Nyctereutes and DC clades. Reclassification of the two basal species of ‘Canis’ into separate genera is proposed (Schaeffia for ‘C.’ adustus, Lupulella for ‘C.’ mesomelas). Although the morphological dataset ranked poorly in both separate and simultaneous analyses (measured by number of minimum‐length topologies, relative number of resolved nodes in the strict consensus of all minimum‐length topologies, consistency and retention indices, nodal dataset influence, and number of extra steps required by the data partition to reach the topology of the combined tree), the morphological synapomorphies represent nearly one quarter of all synapomorphies in the combined tree. Among the hidden morphological support of the combined tree the developmental and behavioural characters are conspicuously abundant.
A case of fatal systemic toxoplasmosis in a cat being treated with cyclosporin A for feline atopy
Authors: LAST ROBERT D. , SUZUKI YASUHIRO , MANNING THOMAS , LINDSAY DAVID , GALIPEAU LAURA , WHITBREAD TREVOR J. 
Published: June 2004

Abstract Acute systemic toxoplasmosis was diagnosed in a 4–5‐year‐old, male, Domestic Short Hair cat, which had been on cyclosporine A immunomodulatory therapy for feline atopy, over an 8‐month period. Cyclosporin A (CsA) has shown promising results as a immunosuppresive agent in the cat for the treatment of eosinophilic plaque and granulomas, allergic cervico‐facial pruritus, feline atopy and other immune‐mediated dermatoses. However, inhibition of T‐lymphocyte function by CsA is believed to have predisposed this cat to the development of a newly acquired, acuteToxoplasma gondiiinfection, as characterized by severe hepatic and pancreatic pathology in conjunction with the heavy parasite load demonstrated on immunohistochemical (IHC) stains forT. gondii. Cats on CsA therapy appear to be at risk of developing fatal systemic toxoplasmosis.
The Fidelity of Misinsertion and Mispair Extension Throughout DNA Synthesis Exhibited by Mutants of the Reverse Transcriptase of Human Immunodeficiency Virus Type 2 Resistant to Nucleoside Analogs
Authors: Taube Ran , Avidan Orna , Hizi Amnon 
Published: June 2004

The AIDS‐causing retroviruses, human immunodeficiency virus types 1 and type 2 (HIV‐1 and HIV‐2, respectively) undergo extensive genetic variations, which effect their pathogenesis and resistance to drug therapy. It was postulated that this genetic hypervariability results from high rates of viral replication in conjugation with a relatively low fidelity of DNA synthesis [typical to the reverse transcriptases (RT) of these retroviruses]. As part of studying structure/function relationship in HIV RT, mutational analyses were conducted to identify amino acid residues which are involved in affecting the fidelity of DNA synthesis. The formation of 3′‐mispaired DNA due to nucleotide misinsertions, and the subsequent elongation of this mismatched DNA were shown to be major determinants in affecting those substitutions during DNA synthesis (exhibited in vitro by HIV RT). It was interesting to find a correlation between sensitivity to nucleoside analogs (due to the ability to incorporate or reject an incoming analog) and the fidelity of DNA synthesis (which depends on the capacity to incorporate and extend a wrong nucleotide). Such a connection has already been found for several drug‐resistant mutants of HIV‐1 RT, with an increased fidelity of DNA synthesis relative to the wild‐type RT.In the present study we have examined the fidelity of DNA synthesis using the same parameters of misinsertion and mispair extension for five novel drug‐resistant mutants of HIV‐2 RT; i.e. the single mutants [Val74]RT, [Gly89]RT and [Tyr215]RT and the double mutants [Val74, Tyr215]RT and [Gly89, Tyr215]RT. This comparative study suggests that unlike the Val74 mutant of HIV‐1 RT, which was shown earlier to display a substantially enhanced fidelity, the comparable mutant of HIV‐2 RT has fidelity similar to that of the wild‐type RT. Depending on the assay employed and the DNA sequences extended, most other mutants of HIV‐2 RT display moderate effects on the enzyme, leading to mild increases in fidelity of DNA synthesis. This implies a more complex and less distinctive correlation between drug‐resistance, misinsertion and mispair extension in HIV‐2 RT in contrast to HIV‐1 RT, providing evidence for potential biochemical differences between these two related RT.
Different Consequences of Incorporating Chloroplast Ribosomal Proteins L12 and S18 into the Bacterial Ribosomes of Escherichia Coli
Authors: Weglöhner Wolfgang , Jünemann Ralf , Von Knoblauch Klaus , Subramanian Alap R. 
Published: June 2004

We have incorporated chloroplast ribosomal proteins (R‐proteins) L12 and S18 into Escherichia coli ribosomes and examined the hybrid ribosomes for their ability to form polysomes in vivo and perform poly(U)‐dependent poly(Phe) synthesis in vitro. The rye chloroplast S18 used for the experiment is a highly divergent protein (170 amino acid residues; E. coli S18, 74 residues), containing a repeating, chloroplast‐specific, heptapeptide motif, and has amino acid sequence identity of only 35% to E. coli S18. When expressed in E. coli, chloroplast S18 was assembled in E. coli ribosomes. The latter formed polysomes in vivo at about the same rate as the host ribosomes, indicating that the replacement of E. coli S18 with its chloroplast homologue has only a minor, if any, effect on function. The L12 protein is much more conserved in sequence and chain length, and is known to have a very important function. The Arabidopsis chloroplast L12 used in the experiment was incorporated into E. coli 50S subunits that associated with the 308 subunits to form ribosomes, but the latter were unable to form polysomes. This result indicates functional inactivation of E. coli ribosomes by a chloroplast R‐protein. To further confirm this result, we overproduced chloroplast L12 through the use of a secretion vector and purified the protein to homogeneity. Chloroplast L12 could be efficiently incorporated in vitro into L7/12‐lacking E. coli ribosomes, but the hybrid ribosomes were totally inactive in poly(U)‐dependent poly(Phe) synthesis. Computer modeling of the spatial structure of all known chloroplast L12 proteins (using E. coli L12 coordinates) indicated a ‘chloroplast loop’ present only in chloroplast L12. The presence of this loop might have a role in the observed inactivation. Taken together with previously reported results (summarized in this paper), it would appear that the features of chloroplast R‐proteins concerned with specific functions are more divergent than their assembly properties.We have previously described methods suitable for overproduction and purification of chloroplast R‐proteins that are encoded in organellar DNA (≈20), but that gave poor yield for those encoded in the nuclear DNA (≈45). Here we describe a method that overcomes this problem and allows the purification of nucleus‐encoded chloroplast R‐proteins in milligram quantities.
Topological Photoaffinity Labeling of the Rabbit Ileal Na+/Bile‐Salt‐Cotransport System
Authors: Kramer Werner , Wess Günther , Bewersdorf Ulrike , Corsiero Daniel , Girbig Frank , Weyland Claudia , Stengelin Siegfried , Enhsen Alfons , Bock Klaus , Kleine Horst , Le Dreau Marie‐Anne , Schäfer Hans‐Ludwig 
Published: June 2004

For the investigation of the topology of the rabbit ileal Na+/bile‐salt‐cotransport system, composed of a 93‐kDa integral membrane protein and a peripheral 14‐kDa bile‐acid‐binding protein (ILBP), we have synthesized photolabile dimeric bile‐salt‐transport inhibitors (photoblockers), G1‐X‐G2, where two bile acid moieties (G1 and G2) are tethered together via a spacer, X. and where one of the two bile acid moieties carries a photoactivatable group. These photoblockers specifically interact with the ileal Na+/bile‐saltcotransport system as demonstrated by a concentration‐dependent inhibition of [3H]cholyltaurine uptake by rabbit ileal brush‐border membrane vesicles and by inhibition of photolabeling of the 93‐kDa and 14‐kDa bile‐salt‐binding proteins by 7,7‐azo and 3,3‐azo derivatives of cholyltaurine. Ileal bile‐salt uptake was specifically inhibited by the photoblockers, which were not taken up themselves by the small intestine as demonstrated by in vivo ileal perfusion.Dependent on the photoblocker used several polypeptides in the molecular‐mass range of 14–130 kDa were labeled. The cytoplasmically attached 14‐kDa ILBP was significantly labeled only by inhibitors that are photoactivatable in bile acid moiety G1, suggesting that during binding and translocation of a bile‐salt molecule by the ileal bile‐salt‐transport system the steroid nucleus gets access to the cytoplasmic site of the ileal brush‐border membrane first. Photoaffinity labeling in the frozen state with the transportable 3,3‐azo and 7,7‐azo derivatives of cholyltaurine revealed a time‐dependent increase in the extent of labeling of the 14‐kDa and 93‐kDa proteins, suggesting a labeling of these proteins from the cytoplasmic site of the ileal brush‐border membrane. By photoaffinity labeling in the frozen state with the various photoblockers time‐dependent changes in the extent of photoaffinity labeling of bile‐salt‐binding proteins were observed, demonstrating the possibility of topological analysis of the rabbit ileal Na+/bile‐saltcotransport system.
Structural and Functional Properties of the 154–171 Wild‐type and Variant Peptides of Human Lecithin‐cholesterol Acyltransferase
Authors: Peelman Frank , Goethals Marc , Vanloo Berlinda , Labeur Christine , Brasseur Robert , Vandekerckhove Joel , Rosseneu Maryvonne 
Published: June 2004

The 154–171 segment of the human lecithin‐cholesterol acyltransferase (LCAT) enzyme was identified as the most stable amphipathic helix in the LCAT sequence. Its mean hydrophobicity, hydrophobic moment and its orientation at a lipid/water interface are similar to those of some of the helical repeats of apolipoprotein A‐IV and E. This domain was therefore proposed as a candidate peptide accounting for the association between LCAT and its lipid substrate. To investigate this hypothesis we synthesized the LCAT‐(154–171)‐peptide, two variants containing the natural Y156N and R158C mutations and a variant with increased hydrophobicity through Y156I, L160I, L163I and Y171W substitutions. The structural and lipid‐binding properties of these synthetic peptides were investigated by turbidity, fluorescence, electron microscopy and circular dichroism.The wild‐type peptide, the R158C variant in its dimeric form, as well as the more hydrophobic peptide, associated with phospholipids, whereas the Y156N and the R158C variant in its monomeric formdid not. However, only the complexes generated with the hydrophobic variant were stable enough to resist dissociation during gel filtration. The wild‐type peptide and hydrophobic variant formed discoidal complexes with dimyristoylglycerophosphocholine (Myr2GraPCho) as shown by negative staining electron microscopy. Comparison of the properties of the wild‐type and hydrophobic variant LCAT‐(154–171)‐peptide stresses the contribution of the hydrophobic face of the amphipathic helix to the formation and stabilization of the peptide/lipid complexes. This is further confirmed by the decreased affinity of the Y156N variant peptide for lipids, as this mutation decreased the mean hydrophobicity of the hydrophobic face of the amphipathic helix. These results support the hypothesis that the 154–171 segment of LCAT might be involved in the interaction of the enzyme with its lipid substrate and suggest that the decreased activity of the Y156N natural LCAT mutant might result from a decreased affinity of this mutant for lipids.
Effects of Dexamethasone Application in Growing Pigs on Hormones, N‐retention and Other Metabolic Parameters
Authors: Lopes S. O. , Claus R. , Lacorn M. , Wagner A. , Mosenthin R. 
Published: June 2004

SummaryMany single effects of glucocorticoids are known but complex metabolic reactions in pigs in response to a glucocorticoid challenge were not reported. Seven pigs (mean weight 69 kg) with indwelling catheters were kept in metabolic crates. After a 7‐day control period they were fed for 9 days with 0.4 mg dexamethasone (dex) per kg body weight daily, followed by another 9‐day post‐treatment period. Hormones and metabolic parameters were continuously determined in urine or blood plasma. Treatment significantly changed all parameters except non‐esterified fatty acids. Cortisol decreased from 84.5 to 4.9 nmol/l, insulin‐like growth factor I (IGF‐I) from 17.5 to 10.8 nmol/l and aldosterone from 0.36 to 0.13 nmol/l. The N‐retention decreased from 1.07 to 0.53 g/kg0.75 and hydroxyproline from 2.97 to 1.05 mmol/day. An increase was found for urine volume (5.2 versus 13.6 l/day), urea‐N (0.90 versus 1.43 g/kg0.75), allantoin (6.40 versus 8.75 mmol/day), glucose (3.9 versus 4.34 mmol/l) and insulin (6.21 versus 11.16 mU/l). In the post‐treatment period IGF‐I revealed a compensatory pattern (control period versus post‐treatment period: 17.5 versus 22.9 nmol/l) whereas the other parameters were not significantly elevated. Data suggest that dex increased N‐excretion both by inhibiting mitosis and resynthesis of proteins partly via a reduced collagen synthesis. Increased allantoin concentrations additionally pointed to increased apoptosis.