bluuebunny/crossref_metadata_2025 huggingface dataset:
High fat diet-induced hyperglycemia: prevention by low level expression of a glucose transporter (GLUT4) minigene in transgenic mice.
Authors: Ikemoto S , Thompson K S , Takahashi M , Itakura H , Lane M D , Ezaki O
Published: May 2006

High-fat intake leading to obesity contributes to the development of non-insulin-dependent diabetes mellitus (NIDDM, type 2). Similarly, mice fed a high-fat (safflower oil) diet develop defective glycemic control, hyperglycemia, and obesity. To assess the effect of a modest increase in the expression of GLUT4 (the insulin-responsive glucose transporter) on impaired glycemic control caused by fat feeding, transgenic mice harboring a GLUT4 minigene were fed a high-fat diet. Low-level tissue-specific (heart, skeletal muscle, and adipose tissue) expression of the GLUT4 minigene in transgenic mice prevented the impairment of glycemic control and accompanying hyperglycemia, but not obesity, caused by fat feeding. Thus, a small increase (< or = 2-fold) in the tissue level of GLUT4 prevents a primary symptom of the diabetic state in a mouse model, suggesting a possible target for intervention in the treatment of NIDDM.
Chicken interferon consensus sequence-binding protein (ICSBP) and interferon regulatory factor (IRF) 1 genes reveal evolutionary conservation in the IRF gene family.
Authors: Jungwirth C , Rebbert M , Ozato K , Degen H J , Schultz U , Dawid I B
Published: May 2006

Members of the IRF family mediate transcriptional responses to interferons (IFNs) and to virus infection. So far, proteins of this family have been studied only among mammalian species. Here we report the isolation of cDNA clones encoding two members of this family from chicken, interferon consensus sequence-binding protein (ICSBP) and IRF-1. The predicted chicken ICSBP and IRF-1 proteins show high levels of sequence similarity to their corresponding human and mouse counterparts. Sequence identities in the putative DNA-binding domains of chicken and human ICSBP and IRF-1 were 97% and 89%, respectively, whereas the C-terminal regions showed identities of 64% and 51%; sequence relationships with mouse ICSBP and IRF-1 are very similar. Chicken ICSBP was found to be expressed in several embryonic tissues, and both chicken IRF-1 and ICSBP were strongly induced in chicken fibroblasts by IFN treatment, supporting the involvement of these factors in IFN-regulated gene expression. The presence of proteins homologous to mammalian IRF family members, together with earlier observations on the occurrence of functionally homologous IFN-responsive elements in chicken and mammalian genes, highlights the conservation of transcriptional mechanisms in the IFN system, a finding that contrasts with the extensive sequence and functional divergence of the IFNs.
Switch from a type 2 to a type 1 T helper cell response and cure of established Leishmania major infection in mice is induced by combined therapy with interleukin 12 and Pentostam.
Authors: Nabors G S , Afonso L C , Farrell J P , Scott P
Published: May 2006

Successful treatment in allergic, autoimmune, and infectious diseases often requires altering the nature of a detrimental immune response mediated by a particular CD4+ T helper (Th) cell subset. While several factors contribute to the development of CD4+ Th1 and Th2 cells, the requirements for switching an established response are not understood. Here we use infection with Leishmania major as a model to investigate those requirements. We report that treatment with interleukin 12 (IL-12), in combination with the antimony-based leishmanicidal drug Pentostam, induces healing in L. major-infected mice and that healing is associated with a switch from a Th2 to a Th1 response. The data suggest that decreasing antigen levels may be required for IL-12 to inhibit a Th2 response and enhance a Th1 response. These observations are important for treatment of nonhealing forms of human leishmaniasis and also demonstrate that in a chronic infectious disease an inappropriate Th2 response can be switched to an effective Th1 response.
Nitric oxide mediates the increase in local cerebral blood flow during focal seizures.
Authors: Pereira de Vasconcelos A , Baldwin R A , Wasterlain C G
Published: May 2006

The role of nitric oxide (NO) in the increase in local cerebral blood flow (LCBF) elicited by focal cortical epileptic seizures was investigated in anesthetized adult rats. Seizures were induced by topical bicuculline methiodide applied through two cranial windows drilled over homotopic sites of the frontal cortex, and LCBF was measured by quantitative autoradiography by using 4-iodo[N-methyl-14C]antipyrine. Superfusion of an inhibitor of NO synthase, N omega-nitro-L-arginine (NA; 1 mM), for 45 min abolished the increase of LCBF induced by topical bicuculline methiodide (10 mM) [164 +/- 18 ml/100 g per min in the artificial cerebrospinal fluid (aCSF)-superfused side and 104 +/- 12 ml/100 g per ml in the NA-superfused side; P < 0.005]. This effect was reversed by coapplication of an excess of L-arginine substrate (10 mM) (218 +/- 22 ml/100 g per min in the aCSF-superfused side and 183 +/- 31 ml/100 g per min in the NA + L-Arg-superfused side) but not by 10 mM D-arginine, a stereoisomer with poor affinity for NO synthase (193 +/- 17 ml/100 g per min in the aCSF-superfused side and 139 +/- 21 ml/100 g per min in the NA + D-Arg-superfused side; P < 0.005). Superfusion of the guanylyl cyclase inhibitor methylene blue attenuated the LCBF increase elicited by topical bicuculline methiodide by 25% +/- 16% (P < 0.05). The present findings suggest that NO is the mediator of the vasodilation in response to focal epileptic seizures.
Development of a K(+)-channel probe and its use for identification of an intracellular plant membrane K+ channel.
Authors: Mi F , Berkowitz G A
Published: May 2006

Polyclonal antibodies were generated against a 9-amino acid, synthetic peptide corresponding to the selectivity filter in the pore region of K(+)-channel proteins. The sequence of amino acids in the ion-conducting pore region of K+ channels is the only highly conserved region of members of this protein family. The objectives of the present work were (i) to determine whether the anti-channel pore peptide antibody was immunoreactive with known K(+)-channel proteins and (ii) to demonstrate the usefulness of the antibody by employing it to identify a newly discovered K(+)-channel protein. Anti-channel pore peptide was immunoreactive with various K(+)-channel subtypes native to a number of different species. Immunoblot analysis demonstrated affinity of the antibody for the drk1, maxi-K, and KAT1 K(+)-channel proteins. Studies also suggested that the anti-channel pore peptide antibody did not immunoreact with membrane proteins other than K+ channels. The anti-channel pore peptide antibody was used to establish the identity of a 62-kDa chloroplast inner envelope polypeptide as a putative component of a K(+)-channel protein. It was concluded that an antibody generated against the conserved pore region/selectivity filter of K+ channels has broad but selective affinity for this class of proteins. This K(+)-channel probe may be a useful tool for identification of K(+)-channel proteins in native membranes.
Heterogeneity in molecular recognition by restriction endonucleases: osmotic and hydrostatic pressure effects on BamHI, Pvu II, and EcoRV specificity.
Authors: Robinson C R , Sligar S G
Published: May 2006

The cleavage specificity of the Pvu II and BamHI restriction endonucleases is found to be dramatically reduced at elevated osmotic pressure. Relaxation in specificity of these otherwise highly accurate and specific enzymes, previously termed "star activity," is uniquely correlated with osmotic pressure between 0 and 100 atmospheres. No other colligative solvent property exhibits a uniform correlation with star activity for all of the compounds tested. Application of hydrostatic pressure counteracts the effects of osmotic pressure and restores the natural selectivity of the enzymes for their canonical recognition sequences. These results indicate that water solvation plays an important role in the site-specific recognition of DNA by many restriction enzymes. Osmotic pressure did not induce an analogous effect on the specificity of the EcoRV endonuclease, implying that selective hydration effects do not participate in DNA recognition in this system. Hydrostatic pressure was found to have little effect on the star activity induced by changes in ionic strength, pH, or divalent cation, suggesting that distinct mechanisms may exist for these observed alterations in specificity. Recent evidence has indicated that BamHI and EcoRI share similar structural motifs, while Pvu II and EcoRV belong to a different structural family. Evidently, the use of hydration water to assist in site-specific recognition is a motif neither limited to nor defined by structural families.
Two auxin-responsive domains interact positively to induce expression of the early indoleacetic acid-inducible gene PS-IAA4/5.
Authors: Ballas N , Wong L M , Ke M , Theologis A
Published: May 2006

The plant growth hormone indole-3-acetic acid (IAA) transcriptionally activates expression of several genes in plants. We have previously identified a 164-bp promoter region (-318 to -154) in the PS-IAA4/5 gene that confers IAA inducibility. Linker-scanning mutagenesis across the region has identified two positive domains: domain A (48 bp; -203 to -156) and domain B (44 bp; -299 to -256), responsible for transcriptional activation of PS-IAA4/5 by IAA. Domain A contains the highly conserved sequence 5'-TGTCCCAT-3' found among various IAA-inducible genes and behaves as the major auxin-responsive element. Domain B functions as an enhancer element which may also contain a less efficient auxin-responsive element. The two domains act cooperatively to stimulate transcription; however, tetramerization of domain A or B compensates for the loss of A or B function. The two domains can also mediate IAA-induced transcription from the heterologous cauliflower mosaic virus 35S promoter (-73 to +1). In vivo competition experiments with icosamers of domain A or B show that the domains interact specifically and with different affinities to low abundance, positive transcription factor(s). A model for transcriptional activation of PS-IAA4/5 by IAA is discussed.
Isolation of a differentially regulated splicing isoform of human NF-E2.
Authors: Pischedda C , Cocco S , Melis A , Marini M G , Kan Y W , Cao A , Moi P
Published: May 2006

The transcription factor NF-E2 (nuclear factor erythroid 2), interacting via DNA motifs within regulatory regions of several hematopoietic genes, is thought to mediate the enhancer activity of the globin locus control regions. By screening a human fetal liver cDNA library with probes derived from mouse NF-E2, we have isolated a splicing variant of the NF-E2 gene (fNF-E2) that differs in the 5' untranslated region from the previously reported cDNA (aNF-E2). The fNF-E2 isoform is transcribed from an alternative promoter located in the 3' end of the first intron and joined by alternative splicing to the second and third exons, which are shared by both RNA isoforms. Although the two forms produce the same protein, they are expressed in different ratios during development. fNF-E2 is more abundant in the fetal liver and less abundant in the adult bone marrow compared to the previously described form. Their distribution apparently follows the differential expression of fetal and adult hemoglobins.
Conditional transformation of a pancreatic beta-cell line derived from transgenic mice expressing a tetracycline-regulated oncogene.
Authors: Efrat S , Fusco-DeMane D , Lemberg H , al Emran O , Wang X
Published: May 2006

Conditional oncogene expression in transgenic mice is of interest for studying the oncoprotein requirements during tumorigenesis and for deriving cell lines that can be induced to undergo growth arrest and enhance their differentiated functions. We utilized the bacterial tetracycline (Tet)-resistance operon regulatory system (tet) from Tn10 of Escherichia coli to control simian virus 40 (SV40) large tumor (T) antigen (TAg) gene expression and to generate conditionally transformed pancreatic beta cells in transgenic mice. A fusion protein containing the tet repressor (tetR) and the activating domain of the herpes simplex virus protein VP16, which converts the repressor into a transcription activator, was produced in beta cells of transgenic mice under control of the insulin promoter. In a separate lineage of transgenic mice, the TAg gene was introduced under control of a tandem array of tet operator sequences and a minimal promoter, which by itself is not sufficient for gene expression. Mice from the two lineages were then crossed to generate double-transgenic mice. Expression of the tetR fusion protein in beta cells activated TAg transcription, resulting in the development of beta-cell tumors. Tumors arising in the absence of Tet were cultured to derive a stable beta-cell line. Cell incubation in the presence of Tet led to inhibition of proliferation, as shown by decreased BrdUrd and [3H]thymidine incorporation. The Tet derivative anhydrotetracycline showed a 100-fold stronger inhibition compared with Tet. When administered in vivo, Tet efficiently inhibited beta-cell proliferation. These findings indicate that transformed beta cells selected for growth during a tumorigenesis process in vivo maintain a dependence on the continuous presence of the TAg oncoprotein for their proliferation. This system provides an approach for generation of beta-cell lines for cell therapy of diabetes as well as conditionally transformed cell lines from other cell types of interest.
Codominance and toxins: a path to drugs of nearly unlimited selectivity.
Authors: Varshavsky A
Published: May 2006

The effectiveness of drugs is often limited by their insufficient selectivity. I propose designs of therapeutic agents that address this problem. The key feature of these reagents, termed comtoxins (codominance-mediated toxins), is their ability to utilize codominance, a property characteristic of many signals in proteins, including degradation signals (degrons) and nuclear localization signals. A comtoxin designed to kill cells that express intracellular proteins P1 and P2 but to spare cells that lack P1 and/or P2 is a multidomain fusion containing a cytotoxic domain and two degrons placed within or near two domains P1* and P2* that bind, respectively, to P1 and P2. In a cell containing both P1 and P2, these proteins would bind to the P1* and P2* domains of the comtoxin and sterically mask the nearby (appropriately positioned) degrons, resulting in a long-lived and therefore toxic drug. By contrast, in a cell lacking P1 and/or P2, at least one of the comtoxin's degrons would be active (unobstructed), yielding a short-lived and therefore nontoxic drug. A comtoxin containing both a degron and a nuclear localization signal can be designed to kill exclusively cells that contain P1 but lack P2. Analogous strategies yield comtoxins sensitive to the presence (or absence) of more than two proteins in a cell. Also considered is a class of comtoxins in which a toxic domain is split by a flexible insert containing binding sites for the target proteins. The potentially unlimited, combinatorial selectivity of comtoxins may help solve the problem of side effects that bedevils present-day therapies, for even nonselective delivery of a comtoxin would not affect cells whose protein "signatures" differ from the targeted one.
Use of binding energy by an RNA enzyme for catalysis by positioning and substrate destabilization.
Authors: Narlikar G J , Gopalakrishnan V , McConnell T S , Usman N , Herschlag D
Published: May 2006

A fundamental catalytic principle for protein enzymes in the use of binding interactions away from the site of chemical transformation for catalysis. We have compared the binding and reactivity of a series of oligonucleotide substrates and products of the Tetrahymena ribozyme, which catalyzes a site-specific phosphodiester cleavage reaction: CCCUCUpA+G<-->CCCUCU-OH+GpA. The results suggest that this RNA enzyme, like protein enzymes, can utilize binding interactions to achieve substantial catalysis via entropic fixation and substrate destabilization. The stronger binding of the all-ribose oligonucleotide product compared to an analog with a terminal 3' deoxyribose residue gives an effective concentration of 2200 M for the 3' hydroxyl group, a value approaching those obtained with protein enzymes and suggesting the presence of a structurally well defined active site capable of precise positioning. The stabilization from tertiary binding interactions is 40-fold less for the oligonucleotide substrate than the oligonucleotide product, despite the presence of the reactive phosphoryl group in the substrate. This destabilization is accounted for by a model in which tertiary interactions away from the site of bond cleavage position the electron-deficient 3' bridging phosphoryl oxygen of the oligonucleotide substrate next to an electropositive Mg ion. As the phosphodiester bond breaks and this 3' oxygen atom develops a negative charge in the transition state, the weak interaction of the substrate with Mg2+ becomes strong. These strategies of "substrate destabilization" and "transition state stabilization" provide estimated rate enhancements of approximately 280- and approximately 60-fold, respectively. Analogous substrate destabilization by a metal ion or hydrogen bond donor may be used more generally by RNA and protein enzymes catalyzing reactions of phosphate esters.
Analysis of the mouse Splotch-delayed mutation indicates that the Pax-3 paired domain can influence homeodomain DNA-binding activity.
Authors: Underhill D A , Vogan K J , Gros P
Published: May 2006

The murine Pax-3 protein contains two DNA-binding domains, a paired domain and a homeodomain, and alterations in the Pax-3 gene are responsible for the neural tube defects observed in the Splotch (Sp) mouse mutant. Of five Sp alleles, Splotch-delayed (Spd) is the only one that encodes a full-length Pax-3 protein, containing a single glycine-to-arginine substitution within the paired domain. To better understand the consequence of this mutation on Pax-3 function, we have analyzed the DNA-binding properties of wild-type and Spd Pax-3, using oligonucleotides that bind primarily to the paired domain (e5) or exclusively to the homeodomain (P2). Wild-type Pax-3 was found to bind e5 in a specific manner. In contrast, the Spd mutation reduced binding of Pax-3 to e5 17-fold, revealing a defect in DNA binding by the paired domain. Surprisingly, the Spd mutation also drastically reduced the homeodomain-specific binding to P2 by 21-fold when compared with the wild-type protein. Interestingly, a deletion which removes the Spd mutation was found to restore P2-binding activity, suggesting that within the full-length Pax-3 protein, the paired domain and homeodomain may interact. We conclude, therefore, that the Spd mutation is phenotyically expressed in vitro by a defect in the DNA-binding properties of Pax-3. Furthermore, it is apparent that the paired domain and homeodomain of Pax-3 do not function as independent domains, since a mutation in the former impairs the DNA-binding activity of the latter.
Expressed cadherin pseudogenes are localized to the critical region of the spinal muscular atrophy gene.
Authors: Selig S , Bruno S , Scharf J M , Wang C H , Vitale E , Gilliam T C , Kunkel L M
Published: May 2006

Low-copy repeats have been associated with genomic rearrangements and have been implicated in the generation of mutations in several diseases. Here we characterize a subset of low-copy repeats in the spinal muscular atrophy (SMA) region in human chromosome 5q13. We show that this repeated sequence, named c41-cad, is a highly expressed pseudogene derived from an intact neuronal cadherin gene, Br-cadherin, situated on 5p13-14. Br-cadherin is expressed specifically in the brain, whereas the c41-cad transcripts are 10-15 times more abundant and are present in all tissues examined. We speculate that the c41-cad repeats, separately or in concert with other repeats in the SMA region, are involved in the pathogenesis of SMA by promoting rearrangements and deletions.
Neurotoxicity of advanced glycation endproducts during focal stroke and neuroprotective effects of aminoguanidine.
Authors: Zimmerman G A , Meistrell M , Bloom O , Cockroft K M , Bianchi M , Risucci D , Broome J , Farmer P , Cerami A , Vlassara H
Published: May 2006

Cerebral infarction (stroke) is a potentially disastrous complication of diabetes mellitus, principally because the extent of cortical loss is greater in diabetic patients than in nondiabetic patients. The etiology of this enhanced neurotoxicity is poorly understood. We hypothesized that advanced glycation endproducts (AGEs), which have previously been implicated in the development of other diabetic complications, might contribute to neurotoxicity and brain damage during ischemic stroke. Using a rat model of focal cerebral ischemia, we show that systemically administered AGE-modified bovine serum albumin (AGE-BSA) significantly increased cerebral infarct size. The neurotoxic effects of AGE-BSA administration were dose- and time-related and associated with a paradoxical increase in cerebral blood flow. Aminoguanidine, an inhibitor of AGE cross-linking, attenuated infarct volume in AGE-treated animals. We conclude that AGEs may contribute to the increased severity of stroke associated with diabetes and other conditions characterized by AGE accumulation.
Mutagenesis of the putative alpha-helical domain of the Vpr protein of human immunodeficiency virus type 1: effect on stability and virion incorporation.
Authors: Mahalingam S , Khan S A , Murali R , Jabbar M A , Monken C E , Collman R G , Srinivasan A
Published: May 2006

vpr is one of the auxiliary genes of human immunodeficiency virus type 1 (HIV-1) and is conserved in the related HIV-2/simian immunodeficiency virus lentiviruses. The unique feature of Vpr is that it is the only nonstructural protein incorporated into the virus particle. Secondary structural analysis predicted an amphipathic alpha-helical domain in the amino terminus of Vpr (residues 17-34) which contains five acidic and four leucine residues. To evaluate the role of specific residues of the helical domain for virion incorporation, mutagenesis of this domain was carried out. Substitution of proline for any of the individual acidic residues (Asp-17 and Glu-21, -24, -25, and -29) eliminated the virion incorporation of Vpr and also altered the stability of Vpr in cells. Conservative replacement of glutamic residues of the helical domain with aspartic residues resulted in Vpr characteristic of wild type both in stability and virion incorporation, as did substitution of glutamine for the acidic residues. In contrast, replacement of leucine residues of the helical domain (residues 20, 22, 23, and 26) by alanine eliminated virion incorporation function of Vpr. These data indicate that acidic and hydrophobic residues and the helical structure in this region are critical for the stability of Vpr and its efficient incorporation into virus-like particles.
Degradation of the cleaved leader peptide of thiolase by a peroxisomal proteinase.
Authors: Authier F , Bergeron J J , Ou W J , Rachubinski R A , Posner B I , Walton P A
Published: May 2006

A peroxisomal location for insulin-degrading enzyme (IDE) has been defined by confocal immunofluorescence microscopy of stably transfected CHO cells overexpressing IDE and digitonin-permeabilization studies in normal nontransfected fibroblasts. The functional significance of IDE in degrading cleaved leader peptides of peroxisomal proteins targeted by the type II motif was evaluated with a synthetic peptide corresponding to the type II leader peptide of prethiolase. The peptide effectively competed for degradation and cross-linking of the high-affinity substrate 125I-labeled insulin to IDE. Direct proteolysis of the leader peptide of prethiolase was confirmed by HPLC; degradation was inhibited by immunodepletion with an antibody to IDE. Phylogenetic analysis of proteinases related to IDE revealed sequence similarity to mitochondrial processing peptidases.
Disease specificity of kinase domains: the src-encoded catalytic domain converts erbB into a sarcoma oncogene.
Authors: Chang C M , Shu H K , Kung H J
Published: May 2006

src and erbB are two tyrosine kinase-encoding oncogenes carried by retroviruses, which have distinct disease specificities. The former induces predominantly sarcomas, and the latter, leukemias. Src and ErbB have similar catalytic domains but have very different regulatory domains. A wealth of information exists concerning how different regulatory domains [Src homology 2 (SH2) and SH3 domains and autophosphorylation sites] control substrate and disease specificities. Whether the catalytic domain helps determine these specificities remains to be explored. Here we show that the Src catalytic domain is enzymatically active when substituted into the ErbB backbone and interacts with the ErbB regulatory domain. This ErbB/Src chimera displays autophosphorylation and substrate phosphorylation patterns different from those of both Src and ErbB. Neither SH2 and SH3 nor autophosphorylation sites are required for the Src catalytic domain to exert its fibroblast transforming ability. Most significantly, the catalytic domain can convert erbB from a leukemogenic oncogene into a sarcomagenic oncogene, suggesting that the leukemogenic determinants in part reside within the ErbB catalytic domain.
Membrane Stretch Slows the Concerted Step prior to Opening in a Kv Channel
Authors: Laitko Ulrike , Juranka Peter F. , Morris Catherine E.
Published: May 2006

In the simplest model of channel mechanosensitivity, expanded states are favored by stretch. We showed previously that stretch accelerates voltage-dependent activation and slow inactivation in a Kv channel, but whether these transitions involve expansions is unknown. Thus, while voltage-gated channels are mechanosensitive, it is not clear whether the simplest model applies. For Kv pore opening steps, however, there is excellent evidence for concerted expansion motions. To ask how these motions respond to stretch, therefore, we have used a Kv1 mutant, Shaker ILT, in which the step immediately prior to opening is rate limiting for voltage-dependent current.

Macroscopic currents were measured in oocyte patches before, during, and after stretch. Invariably, and directly counter to prediction for expansion-derived free energy, ILT current activation (which is limited by the concerted step prior to pore opening) slowed with stretch and the g(V) curve reversibly right shifted. In WTIR (wild type, inactivation removed), the g(V) (which reflects independent voltage sensor motions) is left shifted. Stretch-induced slowing of ILT activation was fully accounted for by a decreased basic forward rate, with no change of gating charge. We suggest that for the highly cooperative motions of ILT activation, stretch-induced disordering of the lipid channel interface may yield an entropy increase that dominates over any stretch facilitation of expanded states. Since tail current τ(V) reports on the opposite (closing) motions, ILT and WTIR τ(V)tail were determined, but the stretch responses were too complex to shed much light.

Shaw is the Kv3 whose voltage sensor, introduced into Shaker, forms the chimera that ILT mimics. Since Shaw2 F335A activation was reportedly a first-order concerted transition, we thought its activation might, like ILT's, slow with stretch. However, Shaw2 F335A activation proved to be sigmoid shaped, so its rate-limiting transition was not a concerted pore-opening transition. Moreover, stretch, via an unidentified non–rate-limiting transition, augmented steady-state current in Shaw2 F335A.

Since putative area expansion and compaction during ILT pore opening and closing were not the energetically consequential determinants of stretch modulation, models incorporating fine details of bilayer structural forces will probably be needed to explain how, for Kv channels, bilayer stretch slows some transitions while accelerating others.
Statistical Limits to the Identification of Ion Channel Domains by Sequence Similarity
Authors: Fodor Anthony A. , Aldrich Richard W.
Published: May 2006

The study of ion channel function is constrained by the availability of structures for only a small number of channels. A commonly used bioinformatics technique is to assert, based on sequence similarity, that a domain within a channel of interest has the same structure as a reference domain for which the structure is known. This technique, while useful, is often employed when there is only a slight similarity between the channel of interest and the domain of known structure. In this study, we exploit recent advances in structural genomics to calculate the sequence-based probability of the presence of putative domains in a number of ion channels. We find strong support for the presence of many domains that have been proposed in the literature. For example, eukaryotic and prokaryotic CLC proteins almost certainly share a common structure. A number of proposed domains, however, are not as well supported. In particular, for the COOH terminus of the BK channel we find a number of literature proposed domains for which the assertion of common structure based on common sequence has a nontrivial probability of error.
Staphylococcus aureus adheres to human intestinal mucus but can be displaced by certain lactic acid bacteria
Authors: Vesterlund Satu , Karp Matti , Salminen Seppo , Ouwehand Arthur C.
Published: May 2006

There is increasing evidence thatStaphylococcus aureusmay colonize the intestinal tract, especially among hospitalized patients. AsStaph. aureushas been found to be associated with certain gastrointestinal diseases, it has become important to study whether this bacterium can colonize the intestinal tract and if so, whether it is possible to prevent colonization. Adhesion is the first step in colonization; this study shows thatStaph. aureusadheres to mucus from resected human intestinal tissue. Certain lactic acid bacteria (LAB), mainly commercial probiotics, were able to reduce adhesion and viability of adherentStaph. aureus. In displacement assays the amount of adherentStaph. aureusin human intestinal mucus was reduced 39–44 % byLactobacillus rhamnosusGG,Lactococcus lactissubsp.lactisandPropionibacterium freudenreichiisubsp.shermanii. Moreover, adherentLactobacillus reuteri,Lc. lactisandP. freudenreichiireduced viability of adherentStaph. aureusby 27–36 %, depending on the strain, after 2 h incubation. This was probably due to the production of organic acids and hydrogen peroxide and possibly in the case ofL. reuterito the production of reuterin. This study shows for the first time thatStaph. aureuscan adhere to human intestinal mucus and adherent bacteria can be displaced and killed by certain LAB strains viain situproduction of antimicrobial substances.
The HA2 haemagglutinin domain of the lysine-specific gingipain (Kgp) of Porphyromonas gingivalis promotes μ-oxo bishaem formation from monomeric iron(III) protoporphyrin IX
Authors: Smalley J. W. , Birss A. J. , Szmigielski B. , Potempa J.
Published: May 2006

The lysine- and arginine-specific gingipains (Kgp, and RgpA and RgpB) are the major proteinases produced by the black-pigmented periodontopathogenPorphyromonas gingivalis. They play a role in degrading host proteins, including haemoglobin, from which is formed the μ-oxo bishaem complex of iron(III) protoporphyrin IX, [Fe(III)PPIX]2O, the major haem component of the black pigment. Kgp and RgpA bind haem and haemoglobin via the haemagglutinin-adhesin 2 (HA2) domain, but the role of this domain in the formation of μ-oxo bishaem-containing pigment is not known. UV-visible spectroscopy was used to examine the interaction of iron(III) protoporphyrin IX monomers [Fe(III)PPIX.OH] with recombinant HA2 and purified HRgpA, Kgp and RgpB gingipains. The HA2 domain reacted with Fe(III)PPIX.OH to form μ-oxo bishaem, the presence of which was confirmed by Fourier transform infrared spectroscopy. Both HRgpA and Kgp, but not RgpB, also mediated μ-oxo bishaem formation and aggregation. It is concluded that the Arg- and Lys-gingipains with HA2 haemagglutinin domains may play a crucial role in haem-pigment formation by converting Fe(III)PPIX.OH monomers into [Fe(III)PPIX]2O and promoting their aggregation.
The relationship between gross motor function and participation restriction in children with cerebral palsy: an exploratory analysis
Authors: Kerr C. , McDowell B. , McDonough S.
Published: May 2006

Background  Children with cerebral palsy (CP) experience a variety of functional limitations depending on the severity of their condition that impact on their participation in day‐to‐day activities.

Methods  The gross motor function and participation restrictions experienced by 60 ambulant children with CP (mean age 11.04 years) were assessed using the Gross Motor Function Measure (GMFM‐88) and the Lifestyle Assessment Questionnaire – Cerebral Palsy (LAQ‐CP).

Results  A significant negative correlation existed between the GMFM‐88 and the LAQ‐CP (r = −0.52, P < 0.001). Significant relationships were also identified between the GMFM‐88 and the physical independence, mobility, economic burden and social integration domains of the LAQ‐CP.

Conclusion  In ambulatory children with CP, better physical function is associated with a lesser impact of disability; however, the relationship between function and participation is complex. Measures of participation restriction may assist with goal setting appropriate to the specific needs of the child and family.
A matched case–control study: investigating the relationship between youth assets and sexual intercourse among 13‐ to 14‐year‐olds
Authors: Doss J. R. , Vesely S. K. , Oman R. F. , Aspy C. B. , Tolma E. , Rodine S. , Marshall L.
Published: May 2006

Background  The number of teenagers engaging in sexual intercourse has consistently changed over the past several years. This can become a major challenge when trying to determine why teens continue to have sex. The purpose of this paper was to investigate the relationship between youth assets and sexual intercourse among 13‐ to 14‐year‐olds.

Methods  Cross‐sectional data were collected using in‐person at‐home interviews from a random sample of inner‐city neighbourhood 13‐ to 14‐year‐old teenagers (n = 64 matched pairs; 36% 13‐year‐olds, 53% female, 45% white, 28% African‐American, 16% Hispanic and 11% Native American). Nine individual youth assets were analysed using conditional logistic regression (matching for several demographic variables) to assess the association between assets and abstinence in younger teens.

Results  Conditional logistic regression analyses showed that two assets, positive Peer Role Models [odds ratios (OR) = 4.67, 95% confidence intervals (CI) = 1.93, 11.27] and Use of Time (Religion) (OR = 2.20, 95% CI = 1.04, 4.65), were significantly related (P < 0.05) to younger teens never having engaged in sexual activity.

Conclusion  These findings suggest, when considering abstinence behaviour, involvement in religious activities and having positive peer role models appear to be protective factors related to delaying sexual intercourse among teens aged 13–14 years.
Bombyx moricell line as a model of immune‐system organs
Authors: Taniai K. , Lee J. H. , Lee I. H.
Published: May 2006

We tested 11Bombyx moricell lines for induction of cecropin B gene (CecB) expression. After the immune challenge,CecBexpression was induced in seven cell lines. A mixture of the cell‐free supernatant from the immune‐responsive cell lines and lipopolysaccharide activated a promoter ofCecBin the non‐immune‐responsive cell line, indicating that secreted factor(s) is involved inCecBactivation. The expressed sequence tags of one of the immune‐responsive cell lines, NISES‐BoMo‐Cam1, contained genes encoding proteins similar to Relish, Cactus, clip‐domain serine protease, serpin, lectin, peptidoglycan recognition protein, 6tox and gloverin, in addition to seven knownB. moriimmune‐inducible genes. These results show that NISES‐BoMo‐Cam1 cells can be used as anin vitromodel of the immune system organs ofB. mori.
A new Minos vector for eye‐specific expression of white+ marker in Ceratitis capitata and in distantly related dipteran species
Authors: Salvemini M. , Mauro U. , Velaeti S. , Polito C. , Saccone G.
Published: May 2006

The genetic transformation of insects by transposable elements is based on the use of selectable genetic markers required to identify transgenic individuals. Conserved regulatory sequences can be used to develop single constructs capable of adequate expression of a marker, across a range of different species. We present evidence that the Drosophila GBS regulatory element (Glass‐binding site), derived from the Rh1 rhodopsin gene, is able to drive in vivo eye‐specific expression of a Ccwhite+ transgene in the Mediterranean fruitfly Ceratitis capitata. The Ceratitis lineage diverged from that of Drosophila∼120 Myr ago. As the GBS regulatory sequence seems to be partially conserved in the more distantly related dipteran species Anopheles gambiae (250 Myr), we propose that the GBS may be widely useful for driving eye‐specific expression in a wide range of dipteran species.
Plasma Levels of Intact and Cleaved Urokinase Receptor Decrease in HIV‐1‐Infected Patients Initiating Highly Active Antiretroviral Therapy
Authors: Ostrowski S. R. , Katzenstein T. L. , Pedersen M. , Høyer‐Hansen G. , Gerstoft J. , Pedersen B. K. , Ullum H.
Published: May 2006

Elevated blood levels of soluble urokinase receptor (suPAR) measured by ELISA decrease in human immunodeficiency virus‐1 (HIV‐1)‐infected patients initiating highly active antiretroviral therapy (HAART). As the suPAR ELISA measures both three‐ and two‐domain suPAR [suPAR(I–III), suPAR(II–III)] and suPAR(I–III)–ligand complexes, the amount by which the individual suPAR forms (suPAR(I–III), suPAR(II–III) and one‐domain suPAR [suPAR(I)]) decrease in plasma in HIV‐1‐infected patients initiating HAART is unknown. Consequently, the objective of this study was to investigate HAART‐induced changes in the individual plasma suPAR forms in HIV‐1‐infected patients. Plasma suPAR was measured by three time‐resolved fluorescence immunoassays detecting suPAR(I–III), suPAR(I–III) + suPAR(II–III) and suPAR(I) in 29 treatment‐naïve HIV‐1‐infected patients followed annually for 5 years after initiation of HAART and in 20 age‐ and gender‐matched healthy individuals. In addition, plasma levels of the following inflammatory markers were also investigated: soluble tumour necrosis factor receptor (sTNFr)‐II, TNF‐α, interleukins (IL)‐10, IL‐6, IL‐4, IL‐2 and interferon (IFN)‐γ. In HIV‐1‐infected patients, plasma suPAR(I–III), suPAR(II–III) and suPAR(I) decreased within the first treatment year (all P < 0.05) and suPAR(I–III) and suPAR(II–III) remained above normal throughout follow‐up (both P < 0.05). Plasma sTNFrII, IL‐6, IFN‐γ and IL‐10 also decreased during HAART (all P < 0.05). In HIV‐1‐infected patients, sTNFrII correlated with all suPAR forms before (all P < 0.01) and after 5 years HAART (all P < 0.001), whereas sTNFrII and suPAR did not correlate in healthy individuals. Intact and cleaved plasma suPAR decreased in HIV‐1‐infected patients initiating HAART but remained above normal. The positive correlation with sTNFrII suggests that the individual plasma suPAR forms are linked to immune activation in HIV‐1 infection.
Successful removal of a slowly growing mediastinal cavernous haemangioma after vascular embolization
Authors: LEE Sung Yong , LEE Ju Han , HUR Gyu Young , KIM Je Hyeong , IN Kwang Ho , KANG Kyung Ho , YOO Se Hwa , SHIM Jae Jeong
Published: May 2006

Abstract:  Mediastinal haemangioma is a rare disease. We report a 23‐year‐old male patient with a posterior mediastinal cavernous haemangioma. The CXR revealed a progressively enlarging mediastinal mass which on chest CT and angiography appeared to be a well‐enhanced hypervascular tumour. Angiographic gel foam embolization of the feeding vessels was undertaken prior to the surgical removal of the mass. The mass lesion following surgical removal was shown to be a cavernous haemangioma on histological examination.
Congenital cystic adenomatoid malformation of the lung in adults: Clinical and CT evaluation of seven patients
Authors: OH Bum Jin , LEE Jin Sung , KIM Jung‐Sun , LIM Chae‐Man , KOH Younsuck
Published: May 2006

Abstract:  Congenital cystic adenomatoid malformation (CCAM) of the lung is a rare congenital developmental abnormality that usually presents in childhood. Some associated malignancies have been reported. This study aimed to describe the clinical and multidetector CT (MDCT) image characteristics of CCAM of the lung in adults. Adult patients with congenital cystic lung diseases in association with surgery for CCAM were evaluated over a five and a half year period. Seven (four women, age range 17–64 years) of 109 congenital cystic lung disease patients were histologically confirmed as having CCAM. The most frequent symptom was productive cough (n = 5) and one patient was admitted with haemoptysis. The diagnosis was based on clinical and radiological findings and one patient was not diagnosed until surgery. MDCT images consisted of having a multiple loculated unilobar cystic mass in six patients and a cavitary mass in one and/or normal systemic arteries. The lesion was present in the right lung in four and in the left lung in three patients. The involved lobe was the upper in three, lower in three and middle lobe in one. Six patients underwent lobectomy and there was no associated malignancy or mortality. The mean length of hospital stay was 17.5 ± 7.3 days. In adult patients who suffer from a recurrent productive cough and who have a multiloculated cystic mass in one lobe and normal vascular images in MDCT, CCAM, although rare, should be considered.
The role of Self‐Defined Race/Ethnicity in Population Structure Control
Authors: Liu X‐Q. , Paterson A. D. , John E. M. , Knight J. A.
Published: May 2006

Population‐based association studies are powerful tools for the genetic mapping of complex diseases. However, this method is sensitive to potential confounding by population structure. While statistical methods that use genetic markers to detect and control for population structure have been the focus of current literature, the utility of self‐defined race/ethnicity in controlling for population structure has been controversial. In this study of 1334 individuals, who self‐identified as either African American, European American or Hispanic, we demonstrated that when the true underlying genetic structure and the self‐defined racial/ethnic groups were roughly in agreement with each other, the self‐defined race/ethnicity information was useful in the control of population structure.
Decision Making Under Risk: A Comparison of Bayesian and Fuzzy Set Methods
Authors: Buckley James J.
Published: May 2006

A classical decision problem is considered where a decision maker is to choose one of a number of actions each offering different consequences. The outcome from a choice of action is uncertain because it depends on the existing state of Nature. Also, the outcome, once an action and state of Nature are specified, may be a vector or a random vector. The decision maker employs both Bayesian methods and fuzzy set techniques to handle the uncertainties. The decision maker is also allowed to use multiple, possibly conflicting, goals in order to determine his best strategy. The Bayesian method produces a set of undominated strategies to choose from, whereas the fuzzy set technique usually produces a unique optimal strategy.
Attempts to Establish a Risk by Analogy
Authors: Fiering Myron , Wilson Richard
Published: May 2006

In this paper, we argue that risk in a new situation can be calculated by comparison with the most closely analogous previous situation that we can find. In many cases, such as automobile accidents, we argue that this year is analogous to preceding years. With toxic chemicals the analogy is less direct—we compare with other toxic chemicals or with chemicals shown to be toxic in other species. Because the unreliability or uncertainty of the analogy can be high, it is necessary to use less sensitive, but more reliable, methods of estimating risk to prevent continued use of a hazardous material, and subsequent tragedy if the hazard should turn out to be unexpectedly large. This suggests more robust techniques to reduce the regret, or societal cost of being wrong, because increased sensitivity is sometimes attained at the expense of sampling error.
Specifying Risk Goals: Inherent Problems with Democratic Institutions
Authors: Lave Lester B. , Romer Thomas
Published: May 2006

Many risks have the property that large numbers of people are exposed and have little or no individual control over the risks they face. Dams, nuclear power plants, and recombinant DNA research have proven controversial not simply because there is vast uncertainty about the true level of risk associated with each, but because a fundamental issue is that in each case social risks can be lessened by spending more on safety: dams can be designed to withstand larger earthquakes, nuclear plants can have additional safety equipment, and DNA research could be done in yet more carefully isolated laboratories. Since each person will have preferences regarding the proper trade‐off between increased cost and increased safety, there is little possibility of consensus. More importantly, we show that a voting process for expressing individual preferences can be manipulated and is seriously flawed in the sense that it does not lead to an “efficient” outcome. In addition, we show that virtually all people are unhappy with the safety decision, in the sense that each would prefer either a safer or a cheaper outcome. Thus, making safety decisions that affect a large group of people who will not be able to control the outcome is even more difficult than has been appreciated. We suggest some ways of handling some of the difficulties.
The Economic Impact of Health Policy Interventions
Authors: Manton Kenneth G. , Stallard Eric , Tolley H. Dennis
Published: May 2006

The rapid aging of the U.S. population, increases in the absolute prevalence of chronic diseases, and the associated rise in the proportion of the GNP expended on medical care all indicate the need for methods to accurately forecast future health care expenditures for specific chronic diseases. Additionally, if these methods are biomedically realistic, they can be used to evaluate the economic implications of specific prevention strategies designed to reduce chronic disease incidence, prevalence, and mortality. Projection strategies that are not biomedically realistic, such as models that assume that risks for demographic subgroups do not change over time (e.g., “static component” models), though possibly accurate over the short run, are not suitable for assessing the long term effects of specific proposed health policy interventions which are designed to alter risks.

In this paper we present a strategy for forecasting health care costs which is based on a model that represents the natural history of a chronic disease in terms of a preclinical state, a clinical state, case fatality rates, cures, and the implications of exogenous medical factors. Using this model we project that the treatment costs associated with respiratory cancer in the white male population of the U.S. may undergo a two‐thirds increase in real dollars over the period 1977 to 2000. About one‐half of this increase is due to a demographic shift to an older population structure, with the remainder due to higher respiratory cancer incidence rates in younger cohorts. Alteration of certain parameters of the model to simulate various interventions suggests that about three‐quarters of the cost of this disease could be eliminated, though realization of any significant part of this savings would require a lengthy phase‐in period.