bluuebunny/crossref_metadata_2025 huggingface dataset:
DNA Variability and Divergence at the Notch Locus in Drosophila melanogaster and D. simulans: A Case of Accelerated Synonymous Site Divergence
Authors: DuMont Vanessa Bauer , Fay Justin C , Calabrese Peter P , Aquadro Charles F
Published: August 2004

DNA diversity in two segments of the Notch locus was surveyed in four populations of Drosophila melanogaster and two of D. simulans. In both species we observed evidence of non-steady-state evolution. In D. simulans we observed a significant excess of intermediate frequency variants in a non-African population. In D. melanogaster we observed a disparity between levels of sequence polymorphism and divergence between one of the Notch regions sequenced and other neutral X chromosome loci. The striking feature of the data is the high level of synonymous site divergence at Notch, which is the highest reported to date. To more thoroughly investigate the pattern of synonymous site evolution between these species, we developed a method for calibrating preferred, unpreferred, and equal synonymous substitutions by the effective (potential) number of such changes. In D. simulans, we find that preferred changes per “site” are evolving significantly faster than unpreferred changes at Notch. In contrast we observe a significantly faster per site substitution rate of unpreferred changes in D. melanogaster at this locus. These results suggest that positive selection, and not simply relaxation of constraint on codon bias, has contributed to the higher levels of unpreferred divergence along the D. melanogaster lineage at Notch.
The Zuker Collection: A Resource for the Analysis of Autosomal Gene Function in Drosophila melanogaster
Authors: Koundakjian Edmund J , Cowan David M , Hardy Robert W , Becker Ann H
Published: August 2004

The majority of genes of multicellular organisms encode proteins with functions that are not required for viability but contribute to important physiological functions such as behavior and reproduction. It is estimated that 75% of the genes of Drosophila melanogaster are nonessential. Here we report on a strategy used to establish a large collection of stocks that is suitable for the recovery of mutations in such genes. From ∼72,000 F3 cultures segregating for autosomes heavily treated with ethyl methanesulfonate (EMS), ∼12,000 lines in which the treated second or third chromosome survived in homozygous condition were selected. The dose of EMS induced an estimated rate of 1.2–1.5 × 10–3 mutations/gene and predicts five to six nonessential gene mutations per chromosome and seven to nine alleles per locus in the samples of 6000 second chromosomes and 6000 third chromosomes. Due to mosaic mutations induced in the initial exposure to the mutagen, many of the lines are segregating or are now fixed for lethal mutations on the mutagenized chromosome. The features of this collection, known as the Zuker collection, make it a valuable resource for forward and reverse genetic screens for mutations affecting a wide array of biological functions.
An Essential Role for the Saccharomyces cerevisiae DEAD-Box Helicase DHH1 in G1/S DNA-Damage Checkpoint Recovery
Authors: Bergkessel Megan , Reese Joseph C
Published: August 2004

The eukaryotic cell cycle displays a degree of plasticity in its regulation; cell cycle progression can be transiently arrested in response to environmental stresses. While the signaling pathways leading to cell cycle arrest are beginning to be well understood, the regulation of the release from arrest has not been well characterized. Here we show that DHH1, encoding a DEAD-box RNA helicase orthologous to the human putative proto-oncogene p54/RCK, is important in release from DNA-damage-induced cell cycle arrest at the G1/S checkpoint. DHH1 mutants are not defective for DNA repair and recover normally from the G2/M and replication checkpoints, suggesting a specific function for Dhh1p in recovery from G1/S checkpoint arrest. Dhh1p has been suggested to play a role in partitioning mRNAs between translatable and nontranslatable pools, and our results implicate this modulation of mRNA metabolism in the recovery from G1/S cell cycle arrest following DNA damage. Furthermore, the high degree of conservation between DHH1 and its human ortholog suggests that this mechanism is conserved among all eukaryotes and potentially important in human disease.
The Genetics of Inviability and Male Sterility in Hybrids Between Anopheles gambiae and An. arabiensis
Authors: Slotman M , Torre A della , Powell J R
Published: August 2004

Male hybrids between Anopheles gambiae and An. arabiensis suffer from hybrid sterility, and inviability effects are sometimes present as well. We examined the genetic basis of these reproductive barriers between the two species, using 21 microsatellite markers. Generally, recessive inviability effects were found on the X chromosome of gambiae that are incompatible with at least one factor on each arabiensis autosome. Inviability is complete when the gambiae and arabiensis inviability factors are hemi- or homozygous. Using a QTL mapping approach, regions that contribute to male hybrid sterility were also identified. The X chromosome has a disproportionately large effect on male hybrid sterility. Additionally, several moderate-to-large autosomal QTL were found in both species. The effect of these autosomal QTL is contingent upon the presence of an X chromosome from the other species. Substantial regions of the autosomes do not contribute markedly to male hybrid sterility. Finally, no evidence for epistatic interactions between conspecific sterility loci was found.
Sequences Upstream of the Homologous cis-elements of the Adh Adult Enhancer of Drosophila Are Required for Maximal Levels of Adh Gene Transcription in Adults of Scaptodrosophila lebanonensis
Authors: Papaceit Montserrat , Orengo Dorcas , Juan Elvira
Published: August 2004

The evolution of cis-regulatory elements is of particular interest for our understanding of the evolution of gene regulation. The Adh gene of Drosophilidae shows interspecific differences in tissue-specific expression and transcript levels during development. In Scaptodrosophila lebanonensis adults, the level of distal transcripts is maximal between the fourth and eighth day after eclosion and is around five times higher than that in D. melanogaster AdhS. To examine whether these quantitative differences are regulated by sequences lying upstream of the distal promoter, we performed in vitro deletion mutagenesis of the Adh gene of S. lebanonensis, followed by P-element-mediated germ-line transformation. All constructs included, as a cotransgene, a modified Adh gene of D. melanogaster (dAdh) in a fixed position and orientation that acted as a chromosomal position control. Using this approach, we have identified a fragment of 1.5 kb in the 5′ region, 830 bp upstream of the distal start site, which is required to achieve maximal levels of distal transcript in S. lebanonensis. The presence of this fragment produces a 3.5-fold higher level of distal mRNA (as determined by real time quantitative PCR) compared with the D. melanogaster dAdh cotransgene. This region contains the degenerated end of a minisatellite sequence expanding farther upstream and does not correspond to the Adh adult enhancer (AAE) of D. melanogaster. Indeed, the cis-regulatory elements of the AAE have been identified by phylogenetic footprinting within the region 830 bp upstream of the distal start site of S. lebanonensis. Furthermore, the deletions Δ-830 and Δ-2358 yield the same pattern of tissue-specific expression, indicating that all tissue-specific elements are contained within the region 830 bp upstream of the distal start site.
Hemolymph Sugar Homeostasis and Starvation-Induced Hyperactivity Affected by Genetic Manipulations of the Adipokinetic Hormone-Encoding Gene in Drosophila melanogaster
Authors: Lee Gyunghee , Park Jae H
Published: August 2004

Adipokinetic hormones (AKHs) are metabolic neuropeptides, mediating mobilization of energy substrates from the fat body in many insects. In delving into the roles of the Drosophila Akh (dAkh) gene, its developmental expression patterns were examined and the physiological functions of the AKH-producing neurons were investigated using animals devoid of AKH neurons and ones with ectopically expressing dAkh. The dAkh gene is expressed exclusively in the corpora cardiaca from late embryos to adult stages. Projections emanating from the AKH neurons indicated that AKH has multiple target tissues as follows: the prothoracic gland and aorta in the larva and the crop and brain in the adult. Studies using transgenic manipulations of the dAkh gene demonstrated that AKH induced both hypertrehalosemia and hyperlipemia. Starved wild-type flies displayed prolonged hyperactivity prior to death; this novel behavioral pattern could be associated with food-searching activities in response to starvation. In contrast, flies devoid of AKH neurons not only lacked this type of hyperactivity, but also displayed strong resistance to starvation-induced death. From these findings, we propose another role for AKH in the regulation of starvation-induced foraging behavior.
Analysis of β-1,3-Glucan Assembly in Saccharomyces cerevisiae Using a Synthetic Interaction Network and Altered Sensitivity to Caspofungin
Authors: Lesage Guillaume , Sdicu Anne-Marie , Ménard Patrice , Shapiro Jesse , Hussein Shamiza , Bussey Howard
Published: August 2004

Large-scale screening of genetic and chemical-genetic interactions was used to examine the assembly and regulation of β-1,3-glucan in Saccharomyces cerevisiae. Using the set of deletion mutants in ∼4600 nonessential genes, we scored synthetic interactions with genes encoding subunits of the β-1,3-glucan synthase (FKS1, FKS2), the glucan synthesis regulator (SMI1/KNR4), and a β-1,3-glucanosyltransferase (GAS1). In the resulting network, FKS1, FKS2, GAS1, and SMI1 are connected to 135 genes in 195 interactions, with 26 of these genes also interacting with CHS3 encoding chitin synthase III. A network core of 51 genes is multiply connected with 112 interactions. Thirty-two of these core genes are known to be involved in cell wall assembly and polarized growth, and 8 genes of unknown function are candidates for involvement in these processes. In parallel, we screened the yeast deletion mutant collection for altered sensitivity to the glucan synthase inhibitor, caspofungin. Deletions in 52 genes led to caspofungin hypersensitivity and those in 39 genes to resistance. Integration of the glucan interaction network with the caspofungin data indicates an overlapping set of genes involved in FKS2 regulation, compensatory chitin synthesis, protein mannosylation, and the PKC1-dependent cell integrity pathway.
An Invertebrate Histocompatibility Complex
Authors: Cadavid Luis F , Powell Anahid E , Nicotra Matthew L , Moreno Maria , Buss Leo W
Published: August 2004

We have developed defined genetic lines of the hydroid Hydractinia symbiolongicarpus and confirmed earlier results showing that allorecognition is controlled by a single chromosomal region within these lines. In a large backcross population, we detected recombinants that display a fusibility phenotype distinct from typical fusion and rejection. We show that this transitory fusion phenotype segregates in a fashion expected of a single Mendelian trait, establishing that the chromosomal interval contains at least two genes that interact to determine fusibility. Using bulked segregant analysis, we have identified amplified fragment length polymorphisms (AFLP) cosegregating with fusibility, used these markers to independently confirm linkage of the two loci, and constructed a 3.4-cM map of an invertebrate histocompatibility complex.
Evolutionary Strata on the Chicken Z Chromosome: Implications for Sex Chromosome Evolution
Authors: Handley Lori-Jayne Lawson , Ceplitis Helene , Ellegren Hans
Published: August 2004

The human X chromosome exhibits four “evolutionary strata,” interpreted to represent distinct steps in the process whereby recombination became arrested between the proto X and proto Y. To test if this is a general feature of sex chromosome evolution, we studied the Z-W sex chromosomes of birds, which have female rather than male heterogamety and evolved from a different autosome pair than the mammalian X and Y. Here we analyze all five known gametologous Z-W gene pairs to investigate the “strata” hypothesis in birds. Comparisons of the rates of synonymous substitution and intronic divergence between Z and W gametologs reveal the presence of at least two evolutionary strata spread over the p and q arms of the chicken Z chromosome. A phylogenetic analysis of intronic sequence data from different avian lineages indicates that Z-W recombination ceased in the oldest stratum (on Zq; CHD1Z, HINTZ, and SPINZ) 102–170 million years ago (MYA), before the split of the Neoaves and Eoaves. However, recombination continued in the second stratum (on Zp; UBAP2Z and ATP5A1Z) until after the divergence of extant avian orders, with Z and W diverging 58–85 MYA. Our data suggest that progressive and stepwise cessation of recombination is a general feature behind sex chromosome evolution.
The Epigenetic Stability of the Locus Control Region-Deficient IgH Locus in Mouse Hybridoma Cells Is a Clonally Varying, Heritable Feature
Authors: Ronai Diana , Berru Maribel , Shulman Marc J
Published: August 2004

Cis-acting elements such as enhancers and locus control regions (LCRs) prevent silencing of gene expression. We have shown previously that targeted deletion of an LCR in the immunoglobulin heavy-chain (IgH) locus creates conditions in which the immunoglobulin μ heavy chain gene can exist in either of two epigenetically inherited states, one in which μ expression is positive and one in which μ expression is negative, and that the positive and negative states are maintained by a cis-acting mechanism. As described here, the stability of these states, i.e., the propensity of a cell to switch from one state to the other, varied among subclones and was an inherited, clonal feature. A similar variation in stability was seen for IgH loci that both lacked and retained the matrix attachment regions associated with the LCR. Our analysis of cell hybrids formed by fusing cells in which the μ expression had different stabilities indicated that stability was also determined by a cis-acting feature of the IgH locus. Our results thus show that a single-copy gene in the same chromosomal location and in the presence of the same transcription factors can exist in many different states of expression.
Quantitative Trait Locus Mapping Based on Resampling in a Vast Maize Testcross Experiment and Its Relevance to Quantitative Genetics for Complex Traits
Authors: Schön Chris C , Utz H Friedrich , Groh Susanne , Truberg Bernd , Openshaw Steve , Melchinger Albrecht E
Published: August 2004

From simulation studies it is known that the allocation of experimental resources has a crucial effect on power of QTL detection as well as on accuracy and precision of QTL estimates. In this study, we used a very large experimental data set composed of 976 F5 maize testcross progenies evaluated in 19 environments and cross-validation to assess the effect of sample size (N), number of test environments (E), and significance threshold on the number of detected QTL, the proportion of the genotypic variance explained by them, and the corresponding bias of estimates for grain yield, grain moisture, and plant height. In addition, we used computer simulations to compare the usefulness of two cross-validation schemes for obtaining unbiased estimates of QTL effects. The maximum, validated genotypic variance explained by QTL in this study was 52.3% for grain moisture despite the large number of detected QTL, thus confirming the infinitesimal model of quantitative genetics. In both simulated and experimental data, the effect of sample size on power of QTL detection as well as on accuracy and precision of QTL estimates was large. The number of detected QTL and the proportion of genotypic variance explained by QTL generally increased more with increasing N than with increasing E. The average bias of QTL estimates and its range were reduced by increasing N and E. Cross-validation performed well with respect to yielding asymptotically unbiased estimates of the genotypic variance explained by QTL. On the basis of our findings, recommendations for planning of QTL mapping experiments and allocation of experimental resources are given.
Statistical Framework for Phylogenomic Analysis of Gene Family Expression Profiles
Authors: Gu Xun
Published: August 2004

Microarray technology has produced massive expression data that are invaluable for investigating the genomewide evolutionary pattern of gene expression. To this end, phylogenetic expression analysis is highly desirable. On the basis of the Brownian process, we developed a statistical framework (called the E0 model), assuming the independent expression of evolution between lineages. Several evolutionary mechanisms are integrated to characterize the pattern of expression diversity after gene duplications, including gradual drift and dramatic shift (punctuated equilibrium). When the phylogeny of a gene family is given, we show that the likelihood function follows a multivariate normal distribution; the variance-covariance matrix is determined by the phylogenetic topology and evolutionary parameters. Maximum-likelihood methods for multiple microarray experiments are developed, and likelihood-ratio tests are designed for testing the evolutionary pattern of gene expression. To reconstruct the evolutionary trace of expression diversity after gene (or genome) duplications, we developed a Bayesian-based method and use the posterior mean as predictors. Potential applications in evolutionary genomics are discussed.
A Novel Gene, msa1, Inhibits Sexual Differentiation in Schizosaccharomyces pombe
Authors: Jeong Hee Tae , Ozoe Fumiyo , Tanaka Katsunori , Nakagawa Tsuyoshi , Matsuda Hideyuki , Kawamukai Makoto
Published: August 2004

Sexual differentiation in the fission yeast Schizosaccharomyces pombe is triggered by nutrient starvation or by the presence of mating pheromones. We identified a novel gene, msa1, which encodes a 533-aa putative RNA-binding protein that inhibits sexual differentiation. Disruption of the msa1 gene caused cells to hypersporulate. Intracellular levels of msa1 RNA and Msa1 protein diminished after several hours of nitrogen starvation. Genetic analysis suggested that the function of msa1 is independent of the cAMP pathway and stress-responsive pathway. Deletion of the ras1 gene in diploid cells inhibited sporulation and in haploid cells decreased expression of mating-pheromone-induced genes such as mei2, mam2, ste11, and rep1; simultaneous deletion of msa1 reversed both phenotypes. Overexpression of msa1 decreased activated Ras1Val17-induced expression of mam2. Phenotypic hypersporulation was similar between cells with deletion of only rad24 and both msa1 and rad24, but simultaneous deletion of msa1 and msa2/nrd1 additively increased hypersporulation. Therefore, we suggest that the primary function of Msa1 is to negatively regulate sexual differentiation by controlling the expression of Ste11-regulated genes, possibly through the pheromone-signaling pathway.
Nonmenstrual bleeding in women under 40 years of age
Authors: Connolly Anne , Jones Siân Esther
Published: August 2004

The complaint of nonmenstrual bleeding, either intermenstrual or postcoital, is a common symptom among women. This complaint is often the result of minor alterations of physiological events caused by the influence of endogenous or exogenous hormones. It is often also associated with a high degree of anxiety. This review briefly outlines the causes of this symptom in this younger age group of women and recommends an evidence‐based approach to their investigation and subsequent management. It is important to ensure that the investigations are rational, relevant and streamlined in order to give reassurance or to begin appropriate treatment without undue delay. Premature ovarian failure is not included in this review. Women in this group who present with bleeding should be investigated as for postmenopausal bleeding.
Implications of informed consent for obstetric research
Authors: Spencer Stephen Andrew , Dawson Angus
Published: August 2004

The new Research Governance Framework places emphasis upon gaining fully informed consent from all potential research participants. In obstetric practice, research projects often involve emergency procedures or treatments at a time when women are distressed. There is a growing tendency not to involve such women in research because of the difficulty in obtaining consent. This could result in failure to develop improved treatments for mothers and babies. This review discusses some of these problems and suggests a number of ways to improve knowledge of research at an early stage of pregnancy as a way of addressing them.
Fractionation, Blood, Plasma Fractionation
Authors: Foster Peter R.
Published: August 2004

Blood plasma fractionation is a biopharmaceutical manufacturing operation in which high quality, proteinaceous products are prepared for clinical use from human plasma. Products prepared in this manner include albumin, eg, human serum albumin, and plasma protein fraction, for volume and protein replacement in surgery and for the treatment of injury and disease; coagulation factors, eg, Factor VIII and Factor IX Complex, for the prevention and treatment of bleeding disorders; and immunoglobulins, eg, immune serum globulin and immune globulin intravenous, for the prevention and treatment of infectious diseases and immune disorders.

A number of highly integrated bioseparation processes are employed to fractionate human plasma into its different constituents. These range from established cold‐ethanol precipitation technology, devised in the 1940s, to more recently developed solid‐phase adsorption/desorption techniques.

The principal developments since 1980 have been immunoglobulin products for intravenous use, and highly effective technologies for the inactivation of viral contaminants, such as hepatitis viruses and Human Immunodeficiency Virus (HIV), which were associated with earlier coagulation factor preparations.
Process Optimization in Copper Electrorefining
Authors: Stelter M. , Bombach H.
Published: August 2004

Copper is one of the major metallic materials together with steel and aluminum. At present, approx. 11 Mt of copper are produced all over the world by electrorefining in sulfuric acid electrolytes. In the last years the current density could be increased to 320–340 A/m2 by simultaneous improvement of the cathode quality, although the parameters “electrolyte” and “anode quality” did not change essentially. This was possible substantially by modifying the cell design, the starter sheets and the optimization of inhibitors and flow control at the electrodes. Further possibilities to optimize this process are described in this paper.
Determination of Ductile Material Properties by Means of the Small Punch Test and Neural Networks
Authors: Abendroth M. , Kuna M.
Published: August 2004

This paper compares two different methods for the identification of ductile properties of materials using the small punch test to measure the material response under loading. The finite element method is used to calculate the load displacement curve of the punch depending on the parameters of a hardening law. Via systematical variation of the material parameters a data base is built up, which is used to train neural networks. The second method allows the indentification of material parameters by using a conjugate directions algorithm, which minimizes the error between an experimental load displacement curve and one calculated by the network function.
Integrated Magnesium Technology
Authors: Eigenfeld K. , Tilch W. , Erchov S. , Podobed O.
Published: August 2004

Recent developments in the field of green sand moulding, together with low cost of moulding materials (green sand), high degree of recyclability of moulding materials and high flexibility of green sand moulding process were the key factors, fostering Foundry Institute of Technical University of Freiberg to start an extensive study on sand casting of magnesium alloys. This study focused on two aspects: technology of green sand moulding for magnesium and mechanical properties of magnesium sand cast parts. Since aluminium‐containing alloys is the most widely used group of magnesium casting alloys, we concentrated on “classic” alloy AZ91HP. Key results of this study are presented in this paper.
Topography of Defect Parameters on Si and GaAs Wafers
Authors: Dornich K. , Gründig‐Wendrock B. , Hahn T. , Niklas J.R.
Published: August 2004

A new measurement technique is presented which is able to analyse defects in semiconductor wafers with pieces of information like DLTS. However, in contrast to DLTS the technique is non‐destructive, contact‐ free and highly spatially resolving. Shallow and deep levels can be investigated in un‐doped or doped semiconductors. In addition, photoconductivity and carrier lifetime topograms of wafers are possible with extremely low injection levels.
Synthesis of Hierarchical Titanium Carbide from Titania‐Coated Cellulose Paper
Authors: Shin Y. , Li X. S. , Wang C. , Coleman J. R. , Exarhos G. J.
Published: August 2004

Cellulose paper and an aqueous‐based, inexpensive TiO2 precursor, Tyzor‐LA, have been used to prepare TiC via carbothermal reduction in an Ar flow. The hierarchical cellulose structures were completely maintained upon the agglomeration of 10–50 nm TiC nanoparticles. The lattice parameter of TiC increased with increasing reaction temperature, while the oxygen content in the sample decreased and showed minimal oxygen impurity at 1500 °C (0.24 wt.‐%).
Salt solubility and deposition in high temperature and pressure aqueous solutions
Authors: Hodes Marc , Griffith Peter , Smith Kenneth A. , Hurst Wilbur S. , Bowers Walter J. , Sako Kentaro
Published: August 2004

Solubility and deposition rate experiments were performed in aqueous sodium sulfate and potassium sulfate solutions at elevated temperatures and pressures typical of the supercritical water oxidation (SCWO) process. The test cell was a six‐port chamber in the form of a modified 1.91 cm (3/4 in.) diameter Swagelok cross with an internally heated cylinder (hot finger) mounted in its center. Solubilities were acquired by maintaining the surface temperature of the hot finger about 10°C above the gradually increasing bulk temperature of the solution flowing by it until salt precipitated on the hot finger. Solubility temperatures for sodium sulfate and potassium sulfate in water were measured for salt concentrations of up to 10% mass fraction. In the deposition rate experiments, the solution flowing past the hot finger was preheated to a temperature close to the solubility temperature and the salt layer–solution interface formed on the hot finger was maintained slightly above the solubility temperature to drive deposition. Deposition rates from SCWO streams containing up to 8% mass fraction salt were obtained by measuring the mass of the salt deposited on the hot finger after each (6 to 12 min) run. Solubility data are compared to those from other studies and a simple deposition rate model is developed and compared with the deposition rate data. Natural convection dominated transport and the system pressure was 25 MPa at all conditions. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2038–2049, 2004
Candidate locus for Gilles de la Tourette syndrome/obsessive compulsive disorder/chronic tic disorder at 18q22
Authors: Cuker Adam , State Matthew W. , King Robert A. , Davis Nicole , Ward David C.
Published: August 2004

Gilles de la Tourette syndrome (GTS), obsessive compulsive disorder (OCD), and chronic tic disorder (CTD) are chronic, potentially debilitating neuropsychiatric disorders that often cluster in families. Comorbidity data and family and linkage studies support the hypothesis that these phenotypes, in some cases, share a common etiology. Studies of chromosomal abnormalities associated with this phenotypic spectrum further show that GTS, OCD, and CTD may represent alternate manifestations of a shared genetic condition. We report on a 14‐year‐old girl with severe OCD and a t(2;18)(p12;q22) translocation. The patient's chromosome 18 breakpoint localizes to the same chromosomal band as two previously reported rearrangements associated with GTS, OCD, and CTD, and fine maps to a genomic position approximately 5 Mb from these rearrangements. The clustering of these three breakpoints within a relatively small genetic interval suggests that 18q22 is a promising region for containing a gene or genes of etiologic importance in the development of the GTS/OCD/CTD phenotypic spectrum. © 2004 Wiley‐Liss, Inc.
Testicular histological examination of spermatogenetic activity in captive gorillas (Gorilla gorilla)
Authors: Enomoto Tomoo , Matsubayashi Kiyoaki , Nakano Mayumi , Fujii‐Hanamoto Hideko , Kusunoki Hiroshi
Published: August 2004

To clarify the reproductive state of male gorillas, we performed histological examinations on the testicles of 10 male gorillas (Gorilla gorilla). The testicular samples were obtained by autopsy, and ordinal histological preparations were made for light microscopy. The poor spermatogenesis of this species was characterized by the following findings: First, spermatogenesis was evident in only four samples. Meiosis progressed in two samples, but they lacked spermatogenesis. In the remaining four specimens, seminiferous tubules hyalinized without any sign of spermatogenesis. Second, seminiferous epithelia were thin even in the males in which spermatogenesis was observed. Third, degenerated seminiferous tubules were found in all specimens. Fourth, abnormally large syncytial cells were found in the tubules. Six stages in the epithelial cycle of the seminiferous tubules were identified. Testosterone staining made it clear that there were many Leydig cells with spherical or fusiform nuclei in an abundance of interstitial tissue. The relevance of the testicular architecture of gorillas to the mating system is discussed. Am. J. Primatol. 63:183–199, 2004. © 2004 Wiley‐Liss, Inc.
Observed case of infanticide committed by a resident male central American black howler monkey (Alouatta pigra)
Authors: Knopff Kyle H. , Knopff Aliah R.A. , Pavelka Mary S.M.
Published: August 2004

Although infanticide has been witnessed in other species of howler monkey, and has been inferred forAlouatta pigra, an observed case of infanticide has not previously been recorded for this species. Here we describe the killing of a 2‐week‐old infant by the resident male of a small social group in southern Belize. The infanticide was witnessed as part of an intensive observational study that began in January 2003. The male was known to have resided in the group for at least 4 months, but it is not known whether he was the father of the infant. The literature proposes three main explanations for infanticide: two adaptive hypotheses (sexual selection and resource competition), and one nonadaptive hypothesis (social pathology). Individual cases of infanticide such as this one are important for comparative purposes, but when examined on their own they are difficult to interpret in relation to established theoretical frameworks. The data presented here show some consistency with the sexual‐selection and resource‐competition hypotheses, but the lack of critical information (i.e., as to paternity) makes it impossible to draw firm conclusions. Am. J. Primatol. 63:239–244, 2004. © 2004 Wiley‐Liss, Inc.
A narcolepsy susceptibility locus maps to a 5Mb region of chromosome 21q
Authors: Dauvilliers Yves , Blouin Jean‐Louis , Neidhart Elisabeth , Carlander Bertrand , Eliaou Jean‐François , Antonarakis Stylianos E. , Billiard Michel , Tafti Mehdi
Published: August 2004

The genetic basis of human narcolepsy remains poorly understood. Multiplex families with full‐blown narcolepsy‐cataplexy are rare, whereas families with both narcolepsy‐cataplexy and excessive daytime sleepiness without cataplexy are more common. We performed a genomewide linkage analysis in a large French family with four members affected with narcolepsy‐cataplexy and 10 others with isolated recurrent naps or lapses into sleep. Only three regions showed logarithm of odds (LOD) scores greater than 1 in two‐point linkage analysis (D6S1960, D11S2359, and D21S228). Genotyping additional markers provided support for linkage to 9 markers on chromosome 21 (maximum two‐point LOD score, 3.36 at D21S1245). The multipoint linkage analysis using SimWalk2 provided further evidence for linkage to the same region (maximum parametric LOD score, 4.00 at 21GT26K). A single haplotype was shared by all affected individuals and informative crossovers indicated that the elusive gene that confers susceptibility to narcolepsy is likely to be located between markers D21S267 and ABCG1, in a 5.15Mb region of 21q. Ann Neurol 2004
Titelbild: Molecular Lithography with DNA Nanostructures (Angew. Chem. 31/2004)
Authors: Deng Zhaoxiang , Mao Chengde
Published: August 2004

Gezielt entworfene DNA‐Nanostrukturen können durch eine molekulare und eine klassische lithographische Technik genau in Metallnanostrukturen repliziert werden. Das rationale Design und die Selbstorganisation der DNA‐Motive ermöglichen Masken mit komplexen Strukturen. Das Titelbild zeigt als Beispiel einen Goldfilm mit periodischen zweidimensionalen Mustern, der von einer selbstorganisierten tetragonalen DNA‐2D‐Anordnung (Wiederholungseinheit ca. 18 nm) repliziert wurde. Einzelheiten dazu finden Sie in der Zuschrift von C. Mao und Z. Deng auf S. 4160 ff.
Cover Picture: Molecular Lithography with DNA Nanostructures (Angew. Chem. Int. Ed. 31/2004)
Authors: Deng Zhaoxiang , Mao Chengde
Published: August 2004

Designed DNA nanostructures …︁ can be accurately replicated into metal nanostructures by a molecular and a classic lithographic approach. The rational design and self‐assembly of DNA motifs allows masks with sophisticated structures to be constructed. The cover picture shows one example, a gold film containing periodic, two‐dimensional features that is replicated from a self‐assembled, tetragonal DNA 2D array (repeating unit about 18 nm). More details can be found in the Communication by C. Mao and Z. Deng on page 4068 ff.
Preparation and properties of compatibilized PVC/SMA‐g‐PA6 blends
Authors: Dong Lijie , Xiong Chuanxi , Wang Tao , Liu Dan , Lu Shengjun , Wang Yinzhen
Published: August 2004

The morphology and mechanical properties of PVC/SMA‐g‐PA6 blends were investigated in this paper. Graft to polymer SMA‐g‐PA6 was prepared via a solution graft reaction between SMA and PA6. FTIR test evidences the occurrence of the graft reaction between SMA and PA6. DSC analysis shows that SMA‐g‐PA6 has a lower melting point of 187°C, which may result in a decrease in crystallinity of PA6 and thus enable efficient blending of SMA‐g‐PA6 and PVC. Compatibilization was evidenced by the dramatic increase in mechanical properties, the smaller particle size and finer dispersion of PA6 in PVC matrix, and, further, a cocontinuous morphology at 16 wt % SMA‐g‐PA6 content. SMA‐g‐PA6 from the solution graft reaction can toughen and reinforce PVC material. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 432–439, 2004
Melt processing of composites of PVDF and carbon black modified with conducting polymers
Authors: Zucolotto V. , Avlyanov J. , Gregorio R. , Mattoso L. H. C.
Published: August 2004

Conductive composites from poly(vinylidene fluoride) (PVDF) and a novel thermally stable conductive additive made via in situ deposition of polyaniline or polypyrrole on carbon black particles were produced by a melting process. Electrical conductivity in the order of 10−2 S/cm could be achieved with low contents of the conductive filler. Thermogravimetric analysis (TGA) showed that there is no appreciable degradation of the composites at temperatures as high as 300°C. Moreover, the addition of the conducting polymer‐modified carbon black additive is advantageous to the melt processing of the composites, reducing the melt viscosity in comparison to the addition of pure carbon black. Composites containing the β‐phase of PVDF could be obtained via quenching from the melt, as indicated by X‐Ray diffraction analysis. The type and amount of the additive and the quenching rate influence the formation of β‐phase in the PVDF composites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 553–557, 2004
A multiple‐dose, safety, tolerability, pharmacokinetics and pharmacodynamic study of oral recombinant human interleukin‐11 (oprelvekin)
Authors: Cotreau Monette M. , Stonis Lucille , Strahs Andrew , Schwertschlag Ullrich S.
Published: August 2004

A study in healthy men and women was performed to assess the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of orally administered recombinant human interleukin‐11 (oprelvekin) (OAO). Four cohorts of 10 subjects each received 3, 5, 10 or 30 mg (8:2/OAO:placebo ratio), first as a single dose with a 7‐day washout period, then 7 consecutive daily doses. Safety was assessed by ongoing evaluation of adverse events (AEs) and laboratory values. PK samples were collected on the first and last day of dose administration. The established effects of subcutaneous oprelvekin on C‐reactive protein (CRP, ↑), platelet count (↑), fibrinogen (↑) and hemoglobin (↓), were evaluated. PK analysis showed that most subjects (27/34, 79%) had undetectable serum levels of IL‐11. PD measures showed no changes from baseline between any OAO group and the placebo group. Orally administered oprelvekin was safe and well tolerated at all doses. A total of five AEs (abdominal pain, diarrhea, headache, rhinitis, grade 3 alanine aminotransferase elevation) were reported across all groups. Evaluations of serum IL‐11 levels indicate that OAO is not systemically absorbed at levels above the lower limit of the bioanalytic assay. These data in addition to the lack of effect on PD measures suggest that there is a decreased potential of systemic adverse events with OAO. Copyright © 2004 John Wiley & Sons, Ltd.
Resistance to oxidative stress caused by ceftazidime and piperacillin in a bioﬁlm of Pseudomonas
Authors: Battán Paola C. , Barnes Ana I. , Albesa Inés
Published: August 2004

The capacity to form a bioﬁlm was evaluated in Pseudomonas aeruginosa isolated from patients with lung and urinary infections. Adherence, development of microcolonies and slime formation varied in the studied strains. P. aeruginosa P63 isolated from cystic ﬁbrosis (CF) exhibited important microcolony formation with the densest bioﬁlm, and was selected to study the oxidative stress produced with ceftazidime and piperacillin by means of chemiluminescence (CL) in cell suspensions and bioﬁlm. P. aeruginosa strain P63 was compared with P69; both were sensitive to ceftazidime and showed increase of reactive species of oxygen (ROS) in the presence of this antibiotic. P. aeruginosas P69 exhibited resistance to piperacillin and low ROS production, while piperacillin‐sensitive strain P63 showed high oxidative stress with this antibiotic. Piperacillin stimulated oxidative stress, increasing ROS production only in the sensitive strain. Higher antibiotic concentrations were necessary to augment ROS in bacteria bioﬁlm than in suspension. Incubation of P63 strain with ceftazidime or piperacillin in the presence of its own extracellular matrix (EM) or sodium alginate stimulated lesser oxidative stress and slower decrease of ROS than in the absence of these polysaccharides. A variant, V10, obtained from strain P63 showed more sensitivity to the antibiotics than the wild‐type, and concomitantly exhibited higher production of ROS in the presence of both the antibiotics studied. Copyright © 2004 John Wiley & Sons, Ltd.
Interobserver variability in the pathological assessment of malignant colorectal polyps
Authors: Komuta K , Batts K , Jessurun J , Snover D , Garcia-Aguilar J , Rothenberger D , Madoff R
Published: August 2004

Background

Treatment of patients with malignant large bowel polyps is highly dependent on pathological evaluation. The aim of this study was to evaluate interobserver variability in the pathological assessment of endoscopically removed polyps.

Methods

The records of 88 patients with colorectal cancer who underwent endoscopic removal of malignant polyps were reviewed. Study investigators reviewed the initial pathology report; three experienced gastrointestinal pathologists reviewed all slides in a blinded fashion. Interobserver variability of pathological assessment of malignant polyps was analysed by κ statistics.

Results

Seventy-six (86 per cent) of the 88 patients had malignant polyps and 12 (14 per cent) had carcinoma in situ. Agreement between experienced pathologists was substantial with regard to T stage (κ = 0·725), resection margin status (κ = 0·668) and Haggitt's classification (κ = 0·682), but comparison of initial and experienced pathologists' assessment demonstrated only moderate agreement in these areas (κ = 0·516, κ = 0·555 and κ = 0·578 respectively). Agreement between even experienced pathologists was poor with respect to histological grade of differentiated adenocarcinomas (κ = 0·163) and angiolymphatic vessel invasion (κ = − 0·017).

Conclusion

Pathological assessment of malignant polyps varies between observers. Specialist pathologists appear to have a higher degree of consensus among themselves than with generalist pathologists with respect to T stage. The high interobserver variability with regard to histological grade of differentiated tumours is clinically irrelevant. However, variability in the assessment of angiolymphatic vessel invasion limits the value of this measurement for clinical decision making.
Assessment of outcomes after colorectal cancer resection in the elderly as a rationale for screening and early detection
Authors: Clark A J , Stockton D , Elder A , Wilson R G , Dunlop M G
Published: August 2004

Background

Clinical, social and survival outcomes in elderly patients undergoing bowel cancer surgery were studied to explore the justification for the current upper age limit in colorectal cancer screening programmes.

Methods

Scottish national data were analysed to determine age-specific population survival following a diagnosis of colorectal cancer. Detailed analysis of outcome variables was undertaken in a cohort of 180 patients aged over 80 years who underwent resection of colorectal cancer.

Results

Population analysis revealed that the absolute risk of developing colorectal cancer was highest in those aged over 80 years, but relative survival was disproportionately poor. Of 180 patients in this age group, 30·0 per cent required an emergency procedure and only 4·6 per cent had Dukes' stage A tumours. Determinants of all-cause mortality were tumour stage (P < 0·001) and degree of co-morbidity (P = 0·004). Some 88·0 per cent of elderly patients returned to the same category of accommodation as that before admission.

Conclusion

Colorectal cancer is increasingly common in people aged over 80 years and survival is disproportionately poor compared with that in other age groups. Elective management of early-stage cancer has a better outcome than emergency surgery. The majority of patients maintain social independence. These population and hospital data provide a rationale for early, and even presymptomatic, detection of colorectal cancer in the elderly.
Contrast-enhanced ultrasonography during liver surgery
Authors: Torzilli G , Del Fabbro D , Olivari N , Calliada F , Montorsi M , Makuuchi M
Published: August 2004

Worthy of wider evaluation
Child protection policy perspectives and reform of Australian legislation
Authors: Farrell Ann
Published: August 2004

Legislative responsibility for child protection has become a major theme in the international human rights arena and a major policy issue within early childhood education and care. This paper examines child protection policy and legislation in Australia and measures that are being employed to safeguard children and childhood within contexts that are seen as increasingly risky. Juxtaposing perspectives on child protection and child liberation, it examines the protective responsibilities speciﬁed in legislation in the context of predominantly adult agendas. Copyright © 2004 John Wiley & Sons, Ltd.
Kinship care in Australia
Authors: Spence Nigel
Published: August 2004

Kinship care is the fastest growing form of out‐of‐home care placement in Australia. It is now a more common form of placement than foster care in some Australian states and is the most common form of placement for Indigenous children nationally. This paper reviews national data and reports ﬁndings from a state (New South Wales) study of the experience of kinship carers, children and workers. Relative carers, children and child welfare caseworkers were found to identify psychological beneﬁts, family obligation and criticism of other forms of care as reasons for preferring kinship care. Legislation and policy, particularly the Aboriginal Child Placement Principle, are also identiﬁed as factors contributing to the rise in kinship care. Concern for the high levels of stress among carers and the low levels of monitoring of children's safety and well‐being are discussed and a stronger policy and practice response from government agencies is proposed. Indications of new policy and programme responses are demonstrated by several recent initiatives at state and national levels. Copyright © 2004 John Wiley & Sons, Ltd.
Multiple forms of violence and other criminal activities as an indicator of severe child maltreatment
Authors: Stanley Janet , Goddard Chris
Published: August 2004

Child protection practice still appears to view child maltreatment as an event largely isolated from other family violence and criminal activities. Research undertaken by the authors suggests that children who have been subjected to the more severe forms of abuse are likely to have come from families who engage in several forms of criminal activity, inside and outside the family, which is often severe in nature. The child who has been maltreated may also become a participant in these activities. The authors recommend that these factors should be investigated in families who have maltreated a child, as the presence or absence of several forms of concurrent violence and other criminal activity may provide an important clue about the welfare of the child. Copyright © 2004 John Wiley & Sons, Ltd.
A Stable Miniature Protein with Oxaloacetate Decarboxylase Activity
Authors: Weston Chris J. , Cureton Charly H. , Calvert Melanie J. , Smart Oliver S. , Allemann Rudolf K.
Published: August 2004

An 18‐residue miniature enzyme, Apoxaldie‐1, has been designed, based on the known structure of the neurotoxic peptide apamin. Three lysine residues were introduced on the solvent‐exposed face of the apamin α‐helix to serve as an active site for decarboxylation of oxaloacetate. The oxidised form of Apoxaldie‐1, in which two disulfide bonds stabilise the α‐helix, formed spontaneously. CD spectroscopy measurements revealed that, in its oxidised form, Apoxaldie‐1 adopted a stably folded structure, which was lost upon reduction of the disulfide bonds. Despite its small size and the absence of a designed binding pocket, Apoxaldie‐1 displayed saturation kinetics in its oxidised form and catalysed the decarboxylation of oxaloacetate at a rate that was almost four orders of magnitude faster than that observed with n‐butylamine. This rivals the performance of the best synthetic oxaloacetate decarboxylases reported to date. Unlike those, however, Apoxaldie‐1 displayed significant stability. It maintained its secondary structure at temperatures in excess of 75 °C, in the presence of high concentrations of guanidinium chloride and at pH values as low as 2.2. Apamin‐based catalysts have potential for the generation of miniature peptides that display activity under nonphysiological conditions.