bluuebunny/crossref_metadata_2025 huggingface dataset:
Pim kinases phosphorylate multiple sites on Bad and promote 14-3-3 binding and dissociation from Bcl-XL
Authors: Macdonald Andrew , Campbell David G , Toth Rachel , McLauchlan Hilary , Hastie C James , Arthur J Simon C
Published: January 2006

Background

Pim-1, 2 and 3 are a group of enzymes related to the calcium calmodulin family of protein kinases. Over-expression of Pim-1 and Pim-2 in mice promotes the development of lymphomas, and up-regulation of Pim expression has been observed in several human cancers.

Results

Here we show that the pim kinases are constitutively active when expressed in HEK-293 cells and are able to phosphorylate the Bcl-2 family member Bad on three residues, Ser112, Ser136 and Ser155 in vitro and in cells. In vitro mapping showed that Pim-2 predominantly phosphorylated Ser112, while Pim-1 phosphorylated Ser112, but also Ser136 and Ser155 at a reduced rate compared to Ser112. Pim-3 was found to be the least specific for Ser112, and the most effective at phosphorylating Ser136 and Ser155. Pim-3 was also able to phosphorylate other sites in Bad in vitro, including Ser170, another potential in vivo site. Mutation of Ser136 to alanine prevented the phosphorylation of Ser112 and Ser155 by Pim kinases in HEK-293 cells, suggesting that this site must be phosphorylated first in order to make the other sites accessible. Pim phosphorylation of Bad was also found to promote the 14-3-3 binding of Bad and block its association with Bcl-XL.

Conclusion

All three Pim kinase family members predominantly phosphorylate Bad on Ser112 and in addition are capable of phosphorylating Bad on multiple sites associated with the inhibition of the pro-apoptotic function of Bad in HEK-293 cells. This would be consistent with the proposed function of Pim kinases in promoting cell proliferation and preventing cell death.
Wnt signaling induces epithelial differentiation during cutaneous wound healing
Authors: Fathke Carrie , Wilson Lynne , Shah Kavita , Kim Brian , Hocking Anne , Moon Randall , Isik Frank
Published: January 2006

Background

Cutaneous wound repair in adult mammals does not regenerate the original epithelial architecture and results in altered skin function. We propose that lack of regeneration may be due to the absence of appropriate molecular signals to promote regeneration. In this study, we investigated the regulation of Wnt signaling during cutaneous wound healing and the consequence of activating either the beta-catenin-dependent or beta-catenin-independent Wnt signaling on epidermal architecture during wound repair.

Results

We determined that the expression of Wnt ligands that typically signal via the beta-catenin-independent pathway is up-regulated in the wound while the beta-catenin-dependent Wnt signaling is activated in the hair follicles adjacent to the wound edge. Ectopic activation of beta-catenin-dependent Wnt signaling with lithium chloride in the wound resulted in epithelial cysts and occasional rudimentary hair follicle structures within the epidermis. In contrast, forced expression of Wnt-5a in the deeper wound induced changes in the interfollicular epithelium mimicking regeneration, including formation of epithelia-lined cysts in the wound dermis, rudimentary hair follicles and sebaceous glands, without formation of tumors.

Conclusion

These findings suggest that adult interfollicular epithelium is capable of responding to Wnt morphogenic signals necessary for restoring epithelial tissue patterning in the skin during wound repair.
Proteomics of early zebrafish embryos
Authors: Link Vinzenz , Shevchenko Andrej , Heisenberg Carl-Philipp
Published: January 2006

Background

Zebrafish (D. rerio) has become a powerful and widely used model system for the analysis of vertebrate embryogenesis and organ development. While genetic methods are readily available in zebrafish, protocols for two dimensional (2D) gel electrophoresis and proteomics have yet to be developed.

Results

As a prerequisite to carry out proteomic experiments with early zebrafish embryos, we developed a method to efficiently remove the yolk from large batches of embryos. This method enabled high resolution 2D gel electrophoresis and improved Western blotting considerably. Here, we provide detailed protocols for proteomics in zebrafish from sample preparation to mass spectrometry (MS), including a comparison of databases for MS identification of zebrafish proteins.

Conclusion

The provided protocols for proteomic analysis of early embryos enable research to be taken in novel directions in embryogenesis.
Recovery and evolutionary analysis of complete integron gene cassette arrays from Vibrio
Authors: Boucher Yan , Nesbø Camilla L , Joss Michael J , Robinson Andrew , Mabbutt Bridget C , Gillings Michael R , Doolittle W Ford , Stokes HW
Published: January 2006

Background

Integrons are genetic elements capable of the acquisition, rearrangement and expression of genes contained in gene cassettes. Gene cassettes generally consist of a promoterless gene associated with a recombination site known as a 59-base element (59-be). Multiple insertion events can lead to the assembly of large integron-associated cassette arrays. The most striking examples are found in Vibrio, where such cassette arrays are widespread and can range from 30 kb to 150 kb. Besides those found in completely sequenced genomes, no such array has yet been recovered in its entirety. We describe an approach to systematically isolate, sequence and annotate large integron gene cassette arrays from bacterial strains.

Results

The complete Vibrio sp. DAT722 integron cassette array was determined through the streamlined approach described here. To place it in an evolutionary context, we compare the DAT722 array to known vibrio arrays and performed phylogenetic analyses for all of its components (integrase, 59-be sites, gene cassette encoded genes). It differs extensively in terms of genomic context as well as gene cassette content and organization. The phylogenetic tree of the 59-be sites collectively found in the Vibrio gene cassette pool suggests frequent transfer of cassettes within and between Vibrio species, with slower transfer rates between more phylogenetically distant relatives. We also identify multiple cases where non-integron chromosomal genes seem to have been assembled into gene cassettes and others where cassettes have been inserted into chromosomal locations outside integrons.

Conclusion

Our systematic approach greatly facilitates the isolation and annotation of large integrons gene cassette arrays. Comparative analysis of the Vibrio sp. DAT722 integron obtained through this approach to those found in other vibrios confirms the role of this genetic element in promoting lateral gene transfer and suggests a high rate of gene gain/loss relative to most other loci on vibrio chromosomes. We identify a relationship between the phylogenetic distance separating two species and the rate at which they exchange gene cassettes, interactions between the non-mobile portion of bacterial genomes and the vibrio gene cassette pool as well as intragenomic translocation events of integrons in vibrios.
Surrogate phenotype definition for alcohol use disorders: a genome-wide search for linkage and association
Authors: Rosenberger Albert , Janicke Nico , Köhler Karola , Korb Katrin , Kulle Bettina , Bickeböller Heike
Published: January 2006

For the identification of susceptibility loci in complex diseases the choice of the target phenotype is very important. We compared results of genome-wide searches for linkage or for association related to three phenotypes for alcohol use disorder. These are a behavioral score BQ, based on a 12-item questionnaire about drinking behavior and the subject's report of drinking-related health problems, and ERP pattern and ERP magnitude, both derived from the eyes closed resting ERP measures to quantify brain activity. Overall, we were able to identify 11 candidate regions for linkage. Only two regions were found to be related to both BQ and one of the ERP phenotypes. The genome-wide search for association using single-nucleotide polymorphisms did not yield interesting leads.
The effect of linkage disequilibrium on linkage analysis of incomplete pedigrees
Authors: Levinson Douglas F , Holmans Peter
Published: January 2006

Dense SNP maps can be highly informative for linkage studies. But when parental genotypes are missing, multipoint linkage scores can be inflated in regions with substantial marker-marker linkage disequilibrium (LD). Such regions were observed in the Affymetrix SNP genotypes for the Genetic Analysis Workshop 14 (GAW14) Collaborative Study on the Genetics of Alcoholism (COGA) dataset, providing an opportunity to test a novel simulation strategy for studying this problem. First, an inheritance vector (with or without linkage present) is simulated for each replicate, i.e., locations of recombinations and transmission of parental chromosomes are determined for each meiosis. Then, two sets of founder haplotypes are superimposed onto the inheritance vector: one set that is inferred from the actual data and which contains the pattern of LD; and one set created by randomly selecting parental alleles based on the known allele frequencies, with no correlation (LD) between markers. Applying this strategy to a map of 176 SNPs (66 Mb of chromosome 7) for 100 replicates of 116 sibling pairs, significant inflation of multipoint linkage scores was observed in regions of high LD when parental genotypes were set to missing, with no linkage present. Similar inflation was observed in analyses of the COGA data for these affected sib pairs with parental genotypes set to missing, but not after reducing the marker map until r
2 between any pair of markers was ≤ 0.05. Additional simulation studies of affected sib pairs assuming uniform LD throughout a marker map demonstrated inflation of significance levels at r
2 values greater than 0.05. When genotypes are available only from two affected siblings in many families in a sample, trimming SNP maps to limit r
2 to 0–0.05 for all marker pairs will prevent inflation of linkage scores without sacrificing substantial linkage information. Simulation studies on the observed pedigree structures and map can also be used to determine the effect of LD on a particular study.
Comparison of family-based association tests in chromosome regions selected by linkage-based confidence intervals
Authors: Lewinger Juan Pablo , Lee Sophia SF , Biernacka Joanna , Wu Long Yang , Shi Haijiang Steven , Bull Shelley B
Published: January 2006

We use the Genetic Analysis Workshop 14 simulated data to explore the effectiveness of a two-stage strategy for mapping complex disease loci consisting of an initial genome scan with confidence interval construction for gene location, followed by fine mapping with family-based tests of association on a dense set of single-nucleotide polymorphisms. We considered four types of intervals: the 1-LOD interval, a basic percentile bootstrap confidence interval based on the position of the maximum Zlr score, and asymptotic and bootstrap confidence intervals based on a generalized estimating equations method. For fine mapping we considered two family-based tests of association: a test based on a likelihood ratio statistic and a transmission-disequilibrium-type test implemented in the software FBAT. In two of the simulation replicates, we found that the bootstrap confidence intervals based on the peak Zlr and the 1-LOD support interval always contained the true disease loci and that the likelihood ratio test provided further strong confirmatory evidence of the presence of disease loci in these regions.
Potts model for haplotype associations
Authors: Moltchanova Elena V , Pitkäniemi Janne , Haapala Laura
Published: January 2006

Bayesian spatial modeling has become important in disease mapping and has also been suggested as a useful tool in genetic fine mapping. We have implemented the Potts model and applied it to the Genetic Analysis Workshop 14 (GAW14) simulated data. Because the "answers" were known we have analyzed latent phenotype P 1-related observed phenotypes affection status (genetically determined) and i (random) in the Danacaa population replicate 2. Analysis of the microsatellite/single-nucleotide polymorphism-based haplotypes at chromosomes 1 and 3 failed to identify multiple clusters of haplotype effects. However, the analysis of separately simulated data with postulated differences in the effects of the two clusters has yielded clear estimated division into the two clusters, demonstrating the correctness of the algorithm. Although we could not clearly identify the disease-related and the non-associated groups of haplotypes, results of both GAW14 and our own simulation encourage us to improve the efficiency and sensitivity of the estimation algorithm and to further compare the proposed method with more traditional methods.
Robust testing of haplotype/disease association
Authors: Allen Andrew S , Satten Glen A
Published: January 2006

Haplotypes, the combination of closely linked alleles that fall on the same chromosome, show great promise for studying the genetic components of complex diseases. However, when only multilocus genotype data are available, statistical approaches need to be employed to resolve haplotype phase ambiguity. Recently, we have proposed an approach to testing and estimating haplotype/disease association that is invariant to any existing genetic structure in the population. Here we evaluate this approach by applying it to the Genetic Analysis Workshop 14 simulated data.
Identification of tag single-nucleotide polymorphisms in regions with varying linkage disequilibrium
Authors: Duggal Priya , Gillanders Elizabeth M , Mathias Rasika A , Ibay Grace P , Klein Alison P , Baffoe-Bonnie Agnes B , Ou Liang , Dusenberry Ian P , Tsai Ya-Yu , Chines Peter S , Doan Betty Q , Bailey-Wilson Joan E
Published: January 2006

We compared seven different tagging single-nucleotide polymorphism (SNP) programs in 10 regions with varied amounts of linkage disequilibrium (LD) and physical distance. We used the Collaborative Studies on the Genetics of Alcoholism dataset, part of the Genetic Analysis Workshop 14. We show that in regions with moderate to strong LD these programs are relatively consistent, despite different parameters and methods. In addition, we compared the selected SNPs in a multipoint linkage analysis for one region with strong LD. As the number of selected SNPs increased, the LOD score, mean information content, and type I error also increased.
Comparisons of methods for linkage analysis and haplotype reconstruction using extended pedigree data
Authors: Lin Shili , Ding Jie , Dong Crystal , Liu Zhenqiu , Ma Zhenxu J , Wan Shuyan , Xu Yan
Published: January 2006

We compare and contrast the performance of SIMPLE, a Monte Carlo based software, with that of several other methods for linkage and haplotype analyses, focusing on the simulated data from the New York City population. First, a whole-genome scan study based on the microsatellite markers was performed using GENEHUNTER. Because GENEHUNTER had to drop individuals for many of the pedigrees, we performed a follow-up study focusing on several regions of interest using SIMPLE, which can handle all pedigrees in their entirety. Second, 3 haplotyping programs, including that in SIMPLE, were used to reconstruct haplotypic configurations in pedigrees. SIMPLE emerges clearly as a preferred tool, as it can handle large pedigrees and produces haplotypic configurations without double recombinant haplotypes. For this study, we had knowledge of the simulating models at the time we performed the analysis.
Modeling the effect of a genetic factor for a complex trait in a simulated population
Authors: Bourgey Mathieu , Leutenegger Anne-Louise , Cousin Emmanuelle , Bourgain Catherine , Babron Marie-Claude , Clerget-Darpoux Françoise
Published: January 2006

Genetic Analysis Workshop 14 simulated data have been analyzed with MASC(marker association segregation chi-squares) in which we implemented a bootstrap procedure to provide the variation intervals of parameter estimates. We model here the effect of a genetic factor, S, for Kofendrerd Personality Disorder in the region of the marker C03R0281 for the Aipotu population. The goodness of fit of several genetic models with two alleles for one locus has been tested. The data are not compatible with a direct effect of a single-nucleotide polymorphism (SNP) (SNP 16, 17, 18, 19 of pack 153) in the region. Therefore, we can conclude that the functional polymorphism has not been typed and is in linkage disequilibrium with the four studied SNPs. We obtained very large variation intervals both of the disease allele frequency and the degree of dominance. The uncertainty of the model parameters can be explained first, by the method used, which models marginal effects when the disease is due to complex interactions, second, by the presence of different sub-criteria used for the diagnosis that are not determined by S in the same way, and third, by the fact that the segregation of the disease in the families was not taken into account. However, we could not find any model that could explain the familial segregation of the trait, namely the higher proportion of affected parents than affected sibs.
Alpha-gliadin genes from the A, B, and D genomes of wheat contain different sets of celiac disease epitopes
Authors: van Herpen Teun WJM , Goryunova Svetlana V , van der Schoot Johanna , Mitreva Makedonka , Salentijn Elma , Vorst Oscar , Schenk Martijn F , van Veelen Peter A , Koning Frits , van Soest Loek JM , Vosman Ben , Bosch Dirk , Hamer Rob J , Gilissen Luud JWJ , Smulders Marinus JM
Published: January 2006

Background

Bread wheat (Triticum aestivum) is an important staple food. However, wheat gluten proteins cause celiac disease (CD) in 0.5 to 1% of the general population. Among these proteins, the α-gliadins contain several peptides that are associated to the disease.

Results

We obtained 230 distinct α-gliadin gene sequences from severaldiploid wheat species representing the ancestral A, B, and D genomes of the hexaploid bread wheat. The large majority of these sequences (87%) contained an internal stop codon. All α-gliadin sequences could be distinguished according to the genome of origin on the basis of sequence similarity, of the average length of the polyglutamine repeats, and of the differences in the presence of four peptides that have been identified as T cell stimulatory epitopes in CD patients through binding to HLA-DQ2/8. By sequence similarity, α-gliadins from the public database of hexaploid T. aestivum could be assigned directly to chromosome 6A, 6B, or 6D. T. monococcum (A genome) sequences, as well as those from chromosome 6A of bread wheat, almost invariably contained epitope glia-α9 and glia-α20, but never the intact epitopes glia-α and glia-α2. A number of sequences from T. speltoides, as well as a number of sequences fromchromosome 6B of bread wheat, did not contain any of the four T cell epitopes screened for. The sequences from T. tauschii (D genome), as well as those from chromosome 6D of bread wheat, were found to contain all of these T cell epitopes in variable combinations per gene. The differences in epitope composition resulted mainly from point mutations. These substitutions appeared to be genome specific.

Conclusion

Our analysis shows that α-gliadin sequences from the three genomes of bread wheat form distinct groups. The four known T cell stimulatory epitopes are distributed non-randomly across the sequences, indicating that the three genomes contribute differently to epitope content. A systematic analysis of all known epitopes in gliadins and glutenins will lead to better understanding of the differences in toxicity among wheat varieties. On the basis of such insight, breeding strategies can be designed to generate less toxic varieties of wheat which may be tolerated by at least part of the CD patient population.
Multilocus analysis of SNP and metabolic data within a given pathway
Authors: Kristensen Vessela N , Tsalenko Anya , Geisler Jurgen , Faldaas Anne , Grenaker Grethe Irene , Lingjærde Ole Christian , Fjeldstad Ståle , Yakhini Zohar , Lønning Per Eystein , Børresen-Dale Anne-Lise
Published: January 2006

Background

Complex traits, which are under the influence of multiple and possibly interacting genes, have become a subject of new statistical methodological research. One of the greatest challenges facing human geneticists is the identification and characterization of susceptibility genes for common multifactorial diseases and their association to different quantitative phenotypic traits.

Results

Two types of data from the same metabolic pathway were used in the analysis: categorical measurements of 18 SNPs; and quantitative measurements of plasma levels of several steroids and their precursors. Using the combinatorial partitioning method we tested various thresholds for each metabolic trait and each individual SNP locus. One SNP in CYP19, 3UTR, two SNPs in CYP1B1 (R48G and A119S) and one in CYP1A1 (T461N) were significantly differently distributed between the high and low level metabolic groups. The leave one out cross validation method showed that 6 SNPs in concert make 65% correct prediction of phenotype. Further we used pattern recognition, computing the p-value by Monte Carlo simulation to identify sets of SNPs and physiological characteristics such as age and weight that contribute to a given metabolic level. Since the SNPs detected by both methods reside either in the same gene (CYP1B1) or in 3 different genes in immediate vicinity on chromosome 15 (CYP19, CYP11 and CYP1A1) we investigated the possibility that they form intragenic and intergenic haplotypes, which may jointly account for a higher activity in the pathway. We identified such haplotypes associated with metabolic levels.

Conclusion

The methods reported here may enable to study multiple low-penetrance genetic factors that together determine various quantitative phenotypic traits. Our preliminary data suggest that several genes coding for proteins involved in a common pathway, that happen to be located on common chromosomal areas and may form intragenic haplotypes, together account for a higher activity of the whole pathway.
Competition between the DNA unwinding and strand pairing activities of the Werner and Bloom syndrome proteins
Authors: Machwe Amrita , Lozada Enerlyn M , Xiao Liren , Orren David K
Published: January 2006

Background

The premature aging and cancer-prone Werner and Bloom syndromes are caused by defects in the RecQ helicase enzymes WRN and BLM, respectively. Recently, both WRN and BLM (as well as several other RecQ members) have been shown to possess a strand annealing activity in addition to the requisite DNA unwinding activity. Since an annealing function would appear to directly oppose the action of a helicase, we have examined in this study the dynamic equilibrium between unwinding and annealing mediated by either WRN or BLM.

Results

Our investigation into the competition between annealing and unwinding demonstrates that, under standard reaction conditions, WRN- or BLM-mediated annealing can partially or completely mask unwinding as measured in standard helicase assays. Several strategies were employed to suppress the annealing activity so that the actual strength of WRN- or BLM-dependent unwinding could be more accurately assessed. Interestingly, if a DNA oligomer complementary to one strand of the DNA substrate to be unwound is added during the helicase reaction, both WRN and BLM unwinding is enhanced, presumably by preventing protein-mediated re-annealing. This strategy allowed measurement of WRN-catalyzed unwinding of long (80 base pair) duplex regions and fully complementary, blunt-ended duplexes, both of which were otherwise quite refractory to the helicase activity of WRN. Similarly, the addition of trap strand stimulated the ability of BLM to unwind long and blunt-ended duplexes. The stimulatory effect of the human replication protein A (hRPA, the eukaryotic single-stranded DNA binding protein) on both WRN- and BLM-dependent unwinding was also re-examined in light of its possible role in preventing re-annealing. Our results show that hRPA influences the outcome of WRN and BLM helicase assays by both inhibiting re-annealing and directly promoting unwinding, with the larger contribution from the latter mechanism.

Conclusion

These findings indicate that measurements of unwinding by WRN, BLM, and probably other RecQ helicases are complicated by their annealing properties. Thus, WRN- and BLM-dependent unwinding activities are significantly stronger than previously believed. Since this broadens the range of potential physiological substrates for WRN and BLM, our findings have relevance for understanding their functions in vitro and in vivo.
Reciprocal regulation of nuclear factor kappa B and its inhibitor ZAS3 after peripheral nerve injury
Authors: Wu Lai-Chu , Goettl Virginia M , Madiai Francesca , Hackshaw Kevin V , Hussain Syed-Rehan A
Published: January 2006

Background

NF-κB binds to the κB motif to regulate transcription of genes involved in growth, immunity and inflammation, and plays a pivotal role in the production of pro-inflammatory cytokines after nerve injuries. The zinc finger protein ZAS3 also binds to the κB or similar motif. In addition to competition for common DNA sites, in vitro experiments have shown that ZAS3 can inhibit NF-κB via the association with TRAF2 to inhibit the nuclear translocation of NF-κB. However, the physiological significance of the ZAS3-mediated inhibition of NF-κB has not been demonstrated. The purpose of this study is to characterize ZAS3 proteins in nervous tissues and to use spinal nerve ligation, a neuropathic pain model, to demonstrate a functional relationship between ZAS3 and NF-κB.

Results

Immunohistochemical experiments show that ZAS3 is expressed in specific regions of the central and peripheral nervous system. Abundant ZAS3 expression is found in the trigeminal ganglion, hippocampal formation, dorsal root ganglia, and motoneurons. Low levels of ZAS3 expressions are also found in the cerebral cortex and in the grey matter of the spinal cord. In those nervous tissues, ZAS3 is expressed mainly in the cell bodies of neurons and astrocytes. Together with results of Western blot analyses, the data suggest that ZAS3 protein isoforms with differential cellular distribution are produced in a cell-specific manner. Further, neuropathic pain confirmed by persistent mechanical allodynia was manifested in rats seven days after L5 and L6 lumbar spinal nerve ligation. Changes in gene expression, including a decrease in ZAS3 and an increase in the p65 subunit of NF-κB were observed in dorsal root ganglion ipsilateral to the ligation when compared to the contralateral side.

Conclusion

ZAS3 is expressed in nervous tissues involved in cognitive function and pain modulation. The down-regulation of ZAS3 after peripheral nerve injury may lead to activation of NF-κB, allowing Wallerian regeneration and induction of NF-κB-dependent gene expression, including pro-inflammatory cytokines. We propose that reciprocal changes in the expression of ZAS3 and NF-κB might generate neuropathic pain after peripheral nerve injury.
Isoflurane depresses hippocampal CA1 glutamate nerve terminals without inhibiting fiber volleys
Authors: Winegar Bruce D , MacIver M Bruce
Published: January 2006

Background

Anesthetic-induced CNS depression is thought to involve reduction of glutamate release from nerve terminals. Recent studies suggest that isoflurane reduces glutamate release by block of Na channels. To further investigate this question we examined the actions of isoflurane, TTX, extracellular Ca2+, CNQX and stimulus voltage (stim) on glutamate-mediated transmission at hippocampal excitatory synapses. EPSPs were recorded from CA1 neurons in rat hippocampal brain slices in response to Schaffer-collateral fiber stimulation.

Results

Isoflurane (350 μM; 1 MAC) reversibly depressed EPSP amplitudes by ~60% while facilitation increased ~20%. Consistent with previous studies, these results indicate a presynaptic site of action that involves reduced excitation-release coupling. EPSPs were depressed to comparable levels by TTX (60 nM) or lowered stim, but facilitation was not changed, indicating a simple failure of axonal conduction. Similarly, partial antagonism of postsynaptic glutamate receptors with CNQX (10 μM) depressed EPSP amplitudes with no change in facilitation. However, EPSP depression by low external Ca2+(0.8 mM) was accompanied by an increase in facilitation comparable to isoflurane. Isoflurane depression of EPSP amplitudes could also be partly reversed by high external Ca2+(4 mM) that also decreased facilitation. Isoflurane or low Ca2+markedly reduced the slopes of fiber volley (FV)-EPSP input-output curves, consistent with little or no effect on FVs. By contrast, TTX didn't alter the FV-EPSP curve slope, indicating that EPSP depression resulted from FV depression. FVs were remarkably resistant to isoflurane. Somatic spike currents were unaffected by 350 μM (1 MAC) isoflurane as well. The EC50for isoflurane depression of FVs was ~2.8 mM (12 vol. %; 8 MAC).

Conclusion

Isoflurane appears to depress CA1 synapses at presynaptic sites downstream from Na channels, as evident by the increased facilitation that accompanies EPSP depression. Fiber volleys did not exhibit depression by isoflurane, as has been reported for other brain regions.
Impact of ε and θ subunits on pharmacological properties of α3β1 GABAA receptors expressed in Xenopus oocytes
Authors: Ranna Martin , Sinkkonen Saku T , Möykkynen Tommi , Uusi-Oukari Mikko , Korpi Esa R
Published: January 2006

Background

γ-Aminobutyric acid type A (GABAA) receptors provide the main inhibitory control in the brain. Their heterogeneity may make it possible to precisely target drug effects to selected neuronal populations.In situhybridization using rat brain sections has revealed a unique expression of GABAAreceptor ε and θ subunit transcripts in the locus coeruleus, where they are accompanied at least by α3, α2, β1 and β3 subunits. Here, we studied the pharmacology of the human α3β1, α3β1ε, α3β1θ and α3β1εθ receptor subtypes expressed inXenopusoocytes and compared them with the γ2 subunit-containing receptors.

Results

The GABA sensitivites and effects of several positive modulators of GABAAreceptors were studied in the absence and the presence of EC25GABA using the two-electrode voltage-clamp method. We found 100-fold differences in GABA sensitivity between the receptors, α3β1ε subtype being the most sensitive and α3β1γ2 the least sensitive. Also gaboxadol dose-response curves followed the same sensitivity rank order, with EC50values being 72 and 411 μM for α3β1ε and α3β1γ2 subtypes, respectively. In the presence of EC25GABA, introduction of the ε subunit to the receptor complex resulted in diminished modulatory effects by etomidate, propofol, pregnanolone and flurazepam, but not by pentobarbital. Furthermore, the α3β1ε subtype displayed picrotoxin-sensitive spontaneous activity. The θ subunit-containing receptors were efficiently potentiated by the anesthetic etomidate, suggesting that θ subunit could bring the properties of β2 or β3 subunits to the receptor complex.

Conclusion

The ε and θ subunits bring additional features to α3β1 GABAAreceptors. These receptor subtypes may constitute as novel drug targets in selected brain regions, e.g., in the brainstem locus coeruleus nuclei.
Muscle fiber-type distribution predicts weight gain and unfavorable left ventricular geometry: a 19 year follow-up study
Authors: Karjalainen Jouko , Tikkanen Heikki , Hernelahti Miika , Kujala Urho M
Published: January 2006

Background

Skeletal muscle consists of type-I (slow-twitch) and type-II (fast-twitch) fibers, with proportions highly variable between individuals and mostly determined by genetic factors. Cross-sectional studies have associated low percentage of type-I fibers (type-I%) with many cardiovascular risk factors.

Methods

We investigated whether baseline type-I% predicts left ventricular (LV) structure and function at 19-year follow-up, and if so, which are the strongest mediating factors. At baseline in 1984 muscle fiber-type distribution (by actomyosin ATPase staining) was studied in 63 healthy men (aged 32–58 years). The follow-up in 2003 included echocardiography, measurement of obesity related variables, physical activity and blood pressure.

Results

In the 40 men not using cardiovascular drugs at follow-up, low type-I% predicted higher heart rate, blood pressure, and LV fractional shortening suggesting increased sympathetic tone. Low type-I% predicted smaller LV chamber diameters (P ≤ 0.009) and greater relative wall thickness (P = 0.034) without increase in LV mass (concentric remodeling). This was explained by the association of type-I% with obesity related variables. Type-I% was an independent predictor of follow-up body fat percentage, waist/hip ratio, weight gain in adulthood, and physical activity (in all P ≤ 0.001). After including these risk factors in the regression models, weight gain was the strongest predictor of LV geometry explaining 64% of the variation in LV end-diastolic diameter, 72% in end-systolic diameter, and 53% in relative wall thickness.

Conclusion

Low type-I% predicts obesity and weight gain especially in the mid-abdomen, and consequently unfavourable LV geometry indicating increased cardiovascular risk.
Left ventricular geometric patterns in newly presenting nigerian hypertensives: An echocardiographic study
Authors: Aje Akinyemi , Adebiyi Adewole A , Oladapo Olulola O , Dada Adekola , Ogah Okechukwu S , Ojji Dike B , Falase Ayodele O
Published: January 2006

Background

Hypertension is a global problem and it is prevalent in Nigeria. Left ventricular hypertrophy is a major complication of hypertension with risk of sudden death and arrhythmias among others. Abnormal left ventricular geometric patterns also increase the burden of morbidity and mortality. It is therefore important to know the different left ventricular geometric patterns in Nigerian hypertensives because of their prognostic significance.

Methods

One hundred (100) newly presenting hypertensives (53 males and 47 females) and 100 controls (53 males and 47 females) were recruited for the study. All were subjected to clinical evaluation and full echocardiographic examination was performed according to the ASE recommendation. The relative wall thickness and the presence or absence of echocardiographic left ventricular hypertrophy were used to determine the various geometric patterns

Results

The mean age of the hypertensive subjects was 56.06 (± 7.68) years while that of the control subjects was 56.10 (± 7.68) years. There was no significant difference in the mean ages of the two groups. In the hypertensive subjects 28% had normal geometry, 26% had concentric remodeling, 28% had concentric hypertrophy and 18% had eccentric hypertrophy. In the control group, 86% had normal geometry, 11% had concentric remodeling, 3% had eccentric hypertrophy and none had concentric hypertrophy. There was statistical significance when the geometric patterns of the hypertensive and controls were compared (χ2 = 74.30, p value < 0.0001).

Conclusion

The study showed that only 28% of the hypertensive subjects had normal LV geometric pattern while 86% of the normal subjects had normal geometry. There is need for longitudinal studies in order to prognosticate the various geometric patterns.
Management and outcome of bleeding pseudoaneurysm associated with chronic pancreatitis
Authors: Hsu Jun-Te , Yeh Chun-Nan , Hung Chien-Fu , Chen Han-Ming , Hwang Tsann-Long , Jan Yi-Yin , Chen Miin-Fu
Published: January 2006

Background

A bleeding pseudoaneurysm in patients with chronic pancreatitis is a rare and potentially lethal complication. Optimal treatment of bleeding peripancreatic pseudoaneurysm remains controversial. This study reports on experience at Chang Gung Memorial Hospital (CGMH) in managing of bleeding pseudoaneurysms associated with chronic pancreatitis.

Methods

The medical records of 9 patients (8 males and 1 female; age range, 28 – 71 years; median, 36 years) with bleeding pseudoaneurysms associated with chronic pancreatitis treated at CGMH between Aug. 1992 and Sep. 2004 were retrospectively reviewed. Alcohol abuse (n = 7;78%) was the predominant predisposing factor. Diagnoses of bleeding pseudoaneurysms were based on angiographic (7/7), computed tomographic (4/7), ultrasound (2/5), and surgical (2/2) findings. Whether surgery or angiographic embolization was performed was primarily based on patient clinical condition. Median follow-up was 38 months (range, 4 – 87 months).

Results

Abdominal computed tomography revealed bleeding pseudoaneurysms in 4 of 7 patients (57%). Angiography determined correct diagnosis in 7 patients (7/7, 100%). The splenic artery was involved in 5 cases, the pancreaticoduodenal artery in 2, the gastroduodenal artery in 1, and the middle colic artery in 1. Initial treatment was emergency (n = 4) or elective (n = 3) surgery in 7 patients and arterial embolization in 2. Rebleeding was detected after initial treatment in 3 patients. Overall, 5 arterial embolizations and 9 surgical interventions were performed; the respective rates of success of these treatments were 20% (1/5) and 89% (8/9). Five patients developed pseudocysts before treatment (n = 3) or following intervention (n = 2). Pseudocyst formation was identified in 2 of the 3 rebleeding patients. Five patients underwent surgical treatment for associated pseudocysts and bleeding did not recur. One patient died from angiography-related complications. Overall mortality rate was 11% (1/9). Surgery-related mortality was 0%.

Conclusion

Angiography is valuable in localizing bleeding pseudoaneurysms. In this limited series, patients with bleeding pseudoaneurysms associated with chronic pancreatitis treated surgically seemingly obtained good outcomes.
Sexually transmitted infections in Saudi Arabia
Authors: Madani Tariq A
Published: January 2006

Background

Data on sexually transmitted infections (STIs) in Saudi Arabia (SA) and other Islamic countries are limited. This study describes the results of a five-year surveillance for STIs in SA.

Methods

This is a case series descriptive study of all confirmed STIs diagnosed in SA from January, 1995 through December, 1999.

Results

A total of 39049 STIs were reported to the Ministry of Health. Reported STIs included nongonococcal urethritis (14557 infections, 37.3%), trichomoniasis (10967 infections, 28.1%), gonococcal urethritis (5547 infections, 14.2%), syphilis (3385 infections, 8.7%), human immunodeficiency virus (2917 infections, 7.5%), genital warts (1382, 3.5%), genital herpes (216 infections, 0.6%), and chancroid (78 infections, 0.2%). The average annual incidence of STIs per 100,000 population for Saudis and non-Saudis, respectively, was as follows: 14.8 and 7.5 for nongonococcal urethritis, 9.4 and 10.4 for trichomoniasis, 5.2 and 4.2 for gonorrhea, 1.7 and 6.4 for syphilis, 0.6 and 8.0 for HIV, 1.4 and 0.7 for genital warts, 0.1 and 0.4 for genital herpes, and 0.1 and 0.1 for chancroid. The incidence of STIs was somewhat steady over the surveillance period except for nongonococcal urethritis which gradually increased.

Conclusion

Nongonococcal urethritis, trichomoniasis, and gonococcal urethritis were the most commonly reported STIs in SA. Even though the incidence of STIs in SA is limited, appropriate preventive strategies that conform to the Islamic rules and values are essential and should be of highest priority for policymakers because of the potential of such infections to spread particularly among the youth.
Comparative evidence for a link between Peyer's patch development and susceptibility to transmissible spongiform encephalopathies
Authors: St Rose Suzanne G , Hunter Nora , Matthews Louise , Foster James D , Chase-Topping Margo E , Kruuk Loeske EB , Shaw Darren J , Rhind Susan M , Will Robert G , Woolhouse Mark EJ
Published: January 2006

Background

Epidemiological analyses indicate that the age distribution of natural cases of transmissible spongiform encephalopathies (TSEs) reflect age-related risk of infection, however, the underlying mechanisms remain poorly understood. Using a comparative approach, we tested the hypothesis that, there is a significant correlation between risk of infection for scrapie, bovine spongiform encephalopathy (BSE) and variant CJD (vCJD), and the development of lymphoid tissue in the gut.

Methods

Using anatomical data and estimates of risk of infection in mathematical models (which included results from previously published studies) for sheep, cattle and humans, we calculated the Spearman's rank correlation coefficient, rs, between available measures of Peyer's patch (PP) development and the estimated risk of infection for an individual of the corresponding age.

Results

There was a significant correlation between the measures of PP development and the estimated risk of TSE infection; the two age-related distributions peaked in the same age groups. This result was obtained for each of the three host species: for sheep, surface area of ileal PP tissue vs risk of infection, rs = 0.913 (n = 19, P < 0.001), and lymphoid follicle density vs risk of infection, rs = 0.933 (n = 19, P < 0.001); for cattle, weight of PP tissue vs risk of infection, rs = 0.693 (n = 94, P < 0.001); and for humans, number of PPs vs risk of infection, rs = 0.384 (n = 46, P = 0.008). In addition, when changes in exposure associated with BSE-contaminated meat were accounted for, the two age-related patterns for humans remained concordant: rs = 0.360 (n = 46, P = 0.014).

Conclusion

Our findings suggest that, for sheep, cattle and humans alike there is an association between PP development (or a correlate of PP development) and susceptibility to natural TSE infection. This association may explain changes in susceptibility with host age, and differences in the age-susceptibility relationship between host species.
Clinical features and outcome of sporadic serogroup W135 disease Taiwan
Authors: Wang Jiun-Ling , Liu Ding-Ping , Yen Jer-Jea , Yu Chia-Jung , Liu Hsi-Chen , Lin Ching-Yuang , Chang Shan-Chwen
Published: January 2006

Background

Few published reports have evaluated the clinical features and outcome of serogroup W135 meningococcal disease. In Taiwan, W135 is the second most prevalent meningococcal disease serogroup.

Method

A nationwide study was conducted to retrospectively analyze epidemiologic data from 115 patients with laboratory confirmed meningococcal disease that occurred from 2001 through 2003.

Results

Serogroup W135 accounted for 26% of all cases and most (76.7%) were older than 20 years. There were no cases of serogroup W135 meningococcal disease associated with Hajj pilgrims, and all cases were sporadic. In 88 patients with complete case records, we compared the presenting symptoms, signs, laboratory data, and outcomes between W135 and non-W135 patients. There were no differences in presenting symptoms except for the higher prevalence of pneumonia found in W135 patients (23.8% vs. 1.5%; OR: 20.6; 95%CI: 2.3–189.0; p = 0.003). The distribution of inflammatory cells in CSF in patients with meningitis was also different between W135 and non-W135 patients. W135 patients had a trend toward more intubations and shock but it did not achieve statistical significance. In multivariate analysis of factors associated with death, three independent factors were found: bacteremia without meningitis, altered mental status, and petechiae or purpura on admission.

Conclusion

Sporadic serogroup W135 meningococcal disease is an important component of the meningococcal disease burden in Taiwan, but it is not directly associated with Hajj pilgrims. Compared with patients infected by other serogroups of meningococci, patients with serogroup W135 were older and more likely to have extrameningeal involvement such as pneumonia.
Microsatellite instability analysis in hereditary non-polyposis colon cancer using the Bethesda consensus panel of microsatellite markers in the absence of proband normal tissue
Authors: Chialina Sergio G , Fornes Claudia , Landi Carolina , de La Vega Elena Carlos D , Nicolorich Maria V , Dourisboure Ricardo J , Solano Angela , Solis Edita A
Published: January 2006

Background

Hereditary non-polyposis colon cancer (HNPCC) is an autosomal dominant syndrome predisposing to the early development of various cancers including those of colon, rectum, endometrium, ovarium, small bowel, stomach and urinary tract. HNPCC is caused by germline mutations in the DNA mismatch repair genes, mostly hMSH2 or hMLH1.

In this study, we report the analysis for genetic counseling of three first-degree relatives (the mother and two sisters) of a male who died of colorectal adenocarcinoma at the age of 23. The family fulfilled strict Amsterdam-I criteria (AC-I) with the presence of extracolonic tumors in the extended pedigree. We overcame the difficulty of having a proband post-mortem non-tumor tissue sample for MSI testing by studying the alleles carried by his progenitors.

Methods

Tumor MSI testing is described as initial screening in both primary and metastasis tumor tissue blocks, using the reference panel of 5 microsatellite markers standardized by the National Cancer Institute (NCI) for the screening of HNPCC (BAT-25, BAT-26, D2S123, D5S346 and D17S250). Subsequent mutation analysis of the hMLH1 and hMSH2 genes was performed.

Results

Three of five microsatellite markers (BAT-25, BAT-26 and D5S346) presented different alleles in the proband's tumor as compared to those inherited from his parents. The tumor was classified as high frequency microsatellite instability (MSI-H). We identified in the HNPCC family a novel germline missense (c.1864C>A) mutation in exon 12 of hMSH2 gene, leading to a proline 622 to threonine (p.Pro622Thr) amino acid substitution.

Conclusion

This approach allowed us to establish the tumor MSI status using the NCI recommended panel in the absence of proband's non-tumor tissue and before sequencing the obligate carrier. According to the Human Gene Mutation Database (HGMD) and the International Society for Gastrointestinal Hereditary Tumors (InSiGHT) Database this is the first report of this mutation.
Cytokeratin 8/18 expression indicates a poor prognosis in squamous cell carcinomas of the oral cavity
Authors: Fillies Thomas , Werkmeister Richard , Packeisen Jens , Brandt Burkhard , Morin Philippe , Weingart Dieter , Joos Ulrich , Buerger Horst
Published: January 2006

Background

Intermediary filaments are involved in cell motility and cancer progression. In a variety of organs, the expression of distinct intermediary filaments are associated with patient prognosis. In this study, we seeked to define the prognostic potential of cytokeratin and vimentin expression patterns in squamous cell carcinomas (SCC's) of the oral cavity.

Methods

308 patients with histologically proven and surgically treated squamous cell carcinomas of the oral cavity were investigated for the immunohistochemical expression of a variety of intermediary filaments including high- and low-molecular weight cytokeratins (Ck's), such as Ck 5/6, Ck 8/18, Ck 1, CK 10, Ck 14, Ck 19 and vimentin, using the tissue microarray technique. Correlations between clinical features and the expression of Cytokeratins and vimentin were evaluated statistically by Kaplan-Meier curves and multivariate Cox regression analysis.

Results

The expression of Ck 8/18 and Ck 19 were overall significantly correlated with a poor clinical prognosis (Ck 8/18 p = 0.04; Ck19 p < 0.01). These findings could also be reproduced for Ck 8/18 in primary nodal-negative SCC's and held true in multivariate-analysis. No significant correlation with patient prognosis could be found for the expression of the other cytokeratins and for vimentin.

Conclusion

The expression of Ck 8/18 in SCC's of the oral cavity is an independent prognostic marker and indicates a decreased overall and progression free survival. These results provide an extended knowledge about the role of intermediary filament expression patterns in SCC's.