bluuebunny/crossref_metadata_2025 huggingface dataset:
Ability of Lysozyme and 2-Deoxyglucose To Differentiate Human and Bovine
Streptococcus bovis
Strains
Authors: Kurtovic Amina , Jarvis Graeme N. , Mantovani Hilário C. , Russell James B.
Published: August 2003

Human and bovine
Streptococcus bovis
strains had the same 16S ribosomal DNA restriction fragment length polymorphism and often had the same patterns of starch, mannitol, lactose, and raffinose utilization. PCRs of BOX sequences differed, but numerical analyses indicated that some human strains clustered with bovine strains. However, human and bovine strains had distinctly different sensitivities to lysozyme and 2-deoxyglucose.
Commercial Broth Microdilution Panel Validation and Reproducibility Trials for Garenoxacin (BMS-284756), a Novel Desfluoroquinolone
Authors: Gordon Kelley A. , Rhomberg Paul R. , Jones Ronald N.
Published: August 2003

Results from garenoxacin dry-form broth microdilution MIC panels prepared commercially (Sensititre, TREK Diagnostics) were compared to reference frozen-form MICs to ensure the validity of the longer-shelf-life product. A total of 1,078 organisms from seven major organism groups were used in this trial. All commercial MIC results were within ± one log
2
dilution of reference garenoxacin values, and reproducibility trials produced identical MIC results for 90.5 to 92.1% of garenoxacin MIC comparisons. Control quinolones (ciprofloxacin and gatifloxacin) also performed at a similarly high level of accuracy.
Acute Cytomegalovirus Infection and Transient Carotid Intimal-Medial Thickening in a Young, Otherwise Healthy Woman
Authors: Hirabayashi Yasuhiko , Ishii Tomonori , Kodera Takao , Fujii Hiroshi , Munakata Yasuhiko , Sasaki Takeshi
Published: August 2003

Carotid intimal-medial thickening was observed in a 23-year-old woman with acute cytomegalovirus (CMV) infection. The thickening disappeared after her recovery from the infection. As endothelial cells are common targets of CMV, this thickening suggests that CMV infection causes vascular lesions, even in otherwise healthy individuals.
Genetic diversity of different apricot geographical groups determined by SSR markers
Authors: Romero Carlos , Pedryc Andrzej , Muñoz Verónica , Llácer Gerardo , Badenes María Luisa
Published: August 2003

Forty apricot cultivars with different geographic origins belonging to the germplasm collections of St. Istvan University (Budapest, Hungary) and the Instituto Valenciano de Investigaciones Agrarias (IVIA) (Valencia, Spain) were studied by means of SSR markers. The aim of the study was to determine the genetic relationships among genotypes from different eco-geographical groups. Sixteen primer pairs flanking microsatellite sequences in the peach genome were assayed. Eleven of them were polymorphic in the set of cultivars studied and allowed every genotype to be unambiguously distinguished. Genetic diversity in the population studied was analyzed using several variability parameters. A total of 34 alleles were detected with a mean value of 3.1 alleles/locus. The expected heterozygosity mean was 0.46 and the observed heterozygosity was 32% on an average leading to a high value of the Wright's fixation index (0.32). Additionally, UPGMA cluster analysis based on Nei's genetic distance grouped genotypes according to their geographic origins and pedigrees. SSR markers have proved to be an efficient tool for fingerprinting cultivars and conducting genetic-diversity studies in apricot.Key words: Prunus armeniaca, molecular markers, microsatellites, diversity.
Development and characterization of EST-derived simple sequence repeat (SSR) markers for pasture grass endophytes
Authors: van Zijll de Jong Eline , Guthridge Kathryn M , Spangenberg German C , Forster John W
Published: August 2003

Fungal endophytes of the genus Neotyphodium are common in temperate pasture grass species and confer both beneficial and deleterious agronomic characteristics to their hosts. The aim of this study was to develop molecular markers based on simple sequence repeat (SSR) loci for the identification and assessment of genetic diversity among Neotyphodium endophytes in grasses. Expressed sequence tags (ESTs) from both Neptyphodium coenophialum and Neotyphodium lolii were examined, and unique SSR loci were identified in 9.7% of the N. coenophialum sequences and 6.3% of the N. lolii sequences. A variety of SSRs were present, although perfect trinucleotide repeat arrays were the most common. Primers were designed to 50 SSR loci from N. coenophialum and 57 SSR loci from N. lolii and were evaluated using 20 Neotyphodium and Epichloë isolates. A high proportion of the N. coenophialum and N. lolii primers produced amplification products from the majority of isolates and most of these primers detected genetic variation. SSR markers from both N. coenophialum and N. lolii detected high levels of polymorphism between Neotyphodium and Epichloë species, and low levels of polymorphism within N. coenophialum and N. lolii. SSR markers may be used in appropriate combinations to discriminate between species. Comparison with amplified fragment length polymorphism (AFLP) data demonstrated that the SSR markers were informative for the assessment of genetic variation within and between endophyte species. These markers may be used to identify endophyte taxa and to evaluate intraspecific population diversity, which may be correlated with variation for endophyte-derived agronomic traits.Key words: Neotyphodium, simple sequence repeats, expressed sequence tags, amplified fragment length polymorphism, genetic diversity.
Effect of prolonged vegetative reproduction of olive tree cultivars (Olea europaea L.) in mitochondrial homoplasmy and heteroplasmy
Authors: García-Díaz Angel , Oya Ricardo , Sánchez Antonio , Luque Francisco
Published: August 2003

The inheritance of mitochondrial and chloroplast genomes does not follow Mendelian laws, but proceeds by vegetative segregation. Most organisms show organelle homoplasmy, which is probably produced and maintained during sexual reproduction. We have tested the effect of prolonged vegetative multiplication in the maintenance of mitochondrial homoplasmy and the generation of heteroplasmy in cultivated olive trees, Olea europaea L. Seven trees, each representing a different variety of olive, were analysed by the study of an intergenic spacer region of the mitochondrial genome. A very high level of heteroplasmy was detected in all cases. We found multiple genome variants of the sequence analysed. The frequency of genomes with no changes in the spacer region was 11.5%. This means that 88.5% of genomes contain at least one change. The same spacer mitochondrial region was sequenced in several clones from four olive trees of a second generation of sexually reproduced trees. In these trees, many clones were identical and had no changes, which represents a clear reduction of the heteroplasmy (p < 0.001). Therefore, this work supports the relevance of the role of sexual reproduction in the maintenance of mitochondrial homoplasmy and also shows that mutations accumulate in a non-coding sequence of the mitochondrial genome when vegetative propagation is maintained for a long period of time.Key words: mitochondrial genome, homoplasmy, heteroplasmy, olive trees, vegetative reproduction, sexual reproduction.
Evaluation of maize microsatellite markers for genetic diversity analysis and fingerprinting in sugarcane
Authors: Selvi A , Nair N V , Balasundaram N , Mohapatra T
Published: August 2003

The use of maize microsatellite markers as a potential cost-effective method for molecular analysis of sugarcane was evaluated. Of the 34 primer pairs obtained from maize genomic libraries, 14 showed repeatable amplifications in Saccharum species clones, commercial hybrids, and the related genera Erianthus, accounting for 41.17% cross transferability. Complex banding patterns were encountered in sugarcane with the number of amplified fragments ranging from 7 to 14 with an average of 10 per primer, indicating the high polyploidy and heterozygosity existing in sugarcane. Phenetic analysis of the SSR polymorphisms produced by nine primers could clearly differentiate the different species of Saccharum and Erianthus and revealed the relationships that existed between them. Genetic similarity co-efficient indicated low diversity existing among the S. officinarum clones (82%) and a relatively higher level of diversity in the S. spontaneum clones (69.7%). Higher level of divergence of Erianthus from Saccharum was also clearly estabilished. Five primers produced genus- and species-specific fragments for Erianthus, S. spontaneum, S. officinarum, and S. barberi. The polymorphic primers, when tested on a panel of 30 commercial sugarcane cultivars, revealed a broad range (32.483.3%) of pair-wise similarity values, indicating their ability to detect high levels of polymorphism. A combination of two primers could differentiate all the varieties, further emphasizing their potential in fingerprinting and varietal identification.Key words: maize microsatellites, Saccharum, Erianthus, diversity analysis, fingerprinting.
Characterization of the red knot (Calidris canutus) mitochondrial control region
Authors: Buehler Deborah M , Baker Allan J
Published: August 2003

We sequenced the complete mitochondrial control regions of 11 red knots (Calidris canutus). The control region is 1168 bp in length and is flanked by tRNA glutamate (glu) and the gene ND6 at its 5' end and tRNA phenylalanine (phe) and the gene 12S on its 3' end. The sequence possesses conserved sequence blocks F, E, D, C, CSB-1, and the bird similarity box (BSB), as expected for a mitochondrial copy. Flanking tRNA regions show correct secondary structure, and a relative rate test indicated no significant difference between substitution rates in the sequence we obtained versus the known mitochondrial sequence of turnstones (Charadriiformes: Scolopacidae). These characteristics indicate that the sequence is mitochondrial in origin. To confirm this, we sequenced the control region of a single individual using both purified mitochondrial DNA and genomic DNA. The sequences were identical using both methods. The sequence and methods presented in this paper may now serve as a reference for future studies using knot and other avian control regions. Furthermore, the discovery of five variable sites in 11 knots towards the 3' end of the control region, and the variability of this region in contrast to the more conserved central domain in the alignment between knots and other Charadriiformes, highlights the importance of this area as a source of variation for future studies in knots and other birds.Key words: D-loop, Calidris canutus, Charadriiformes, Aves, evolution.
Expected Value Operator of Random Fuzzy Variable and Random Fuzzy Expected Value Models
Authors: Liu Yian-Kui , Liu Baoding
Published: August 2003

Random fuzzy variable is mapping from a possibility space to a collection of random variables. This paper first presents a new definition of the expected value operator of a random fuzzy variable, and proves the linearity of the operator. Then, a random fuzzy simulation approach, which combines fuzzy simulation and random simulation, is designed to estimate the expected value of a random fuzzy variable. Based on the new expected value operator, three types of random fuzzy expected value models are presented to model decision systems where fuzziness and randomness appear simultaneously. In addition, random fuzzy simulation, neural networks and genetic algorithm are integrated to produce a hybrid intelligent algorithm for solving those random fuzzy expected valued models. Finally, three numerical examples are provided to illustrate the feasibility and the effectiveness of the proposed algorithm.
Stereotactic Target Localization Accuracy in Interventional Magnetic Resonance Imaging
Authors: Samset Eigil , Hirschberg Henry
Published: August 2003

Objective: To compare stereotactic target determination, based on images obtained from interventional MRI (iMRI), conventional closed MR and CT. Methods: Stereotactic coordinates for 55 targets in an artificial scull were derived from iMRI scans and compared using CT as the standard. Stereotactic coordinates were also derived from iMRI scans in a series of patients and compared using iMRI fused with CT as the standard. Results: The mean difference between targets in the skull phantom determined from iMRI and CT images was 0.90 ± 0.28 mm, with a maximum difference of 1.57 mm. The mean difference between targets in the patients derived from iMRI alone and interventional MR fused with CT was 1.39 ± 0.54 mm, with a maximum difference of 2.47 mm. Discussion: The results indicate that iMRI can be used for stereotactic target localization.
Frameless Stereotaxy without Rigid Pin Fixation during Awake Craniotomies
Authors: Leuthardt Eric C. , Fox Douglas , Ojemann George A. , Dacey Ralph G. , Grubb Robert L. , Rich Keith M. , Ojemann Jeffrey G.
Published: August 2003

Objective: The accuracy and precision of resection with awake brain mapping is augmented when combined with frameless stereotaxy. Frameless stereotactic assisted surgery, however, typically involves immobilization in Mayfield pins. Rigid fixation, however, may be problematic for individuals undergoing awake craniotomy. We describe an alternate method of frameless stereotaxy without the use of pin fixation. Methods: The MRI fiducials are placed in proximity to the proposed incision and prepared and draped in the operative field. After craniotomy, the epidural skull clamp (standardly used to support the electrode holder during corticography) is attached. Using the Stealth Navigational System, a spinal reference arc is then clamped onto the skull clamp base. After the fiducials and arc are registered, the probe is used for frameless guidance. Results: In 14 of 15 cases (93%), this technique was successful. One case failed because of close proximity of the fiducials to the incision. The accuracy of the 14 successful cases was less than 4 mm. The error within the lesion itself was always less than 2 mm. Overall, these results are comparable to those achieved using a Mayfield head holder. In all tumor cases, postoperative imaging concurred with intraoperative assessment of a total versus subtotal resection. Conclusions: By affixing the spinal arc to the skull, the complications and discomfort associated with pin fixation are avoided completely. The patient is free to move without affecting the accuracy. The spine arc, in combination with the skull clamp, provides an efficient, well-tolerated, and accurate method of frameless navigation for the awake patient undergoing craniotomy.
Transcription Regulators Potentially Controlled by HPr Kinase/Phosphorylase in Gram-Negative Bacteria
Authors: Boël Grégory , Mijakovic Ivan , Mazé Alain , Poncet Sandrine , Taha Muhamed-Kheir , Larribe Mireille , Darbon Emmanuelle , Khemiri Arbia , Galinier Anne , Deutscher Josef
Published: August 2003

Phosphorylation and dephosphorylation at Ser-46 in HPr, a phosphocarrier protein of the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS) is controlled by the bifunctional HPr kinase/phosphorylase (HprK/P). In Gram-positive bacteria, P-Ser-HPr controls (1) sugar uptake via the PTS; (2) catabolite control protein A (CcpA)-mediated carbon catabolite repression, and (3) inducer exclusion. Genome sequencing revealed that HprK/P is absent from Gram-negative enteric bacteria, but present in many other proteobacteria. These organisms also possess (1) HPr, the substrate for HprK/P; (2) enzyme I, which phosphorylates HPr at His-15, and (3) one or several enzymes IIA, which receive the phosphoryl group from P∼His-HPr. The genes encoding the PTS proteins are often organized in an operon with hprK. However, most of these organisms miss CcpA and a functional PTS, as enzymes IIB and membrane-integrated enzymes IIC seem to be absent. HprK/P and the rudimentary PTS phosphorylation cascade in Gram-negative bacteria must therefore carry out functions different from those in Gram-positive organisms. The gene organization in many HprK/P-containing Gram-negative bacteria as well as some preliminary experiments suggest that HprK/P might control transcription regulators implicated in cell adhesion and virulence. In α-proteobacteria, hprK is located downstream of genes encoding a two-component system of the EnvZ/OmpR family. In several other proteobacteria, hprK is organized in an operon together with genes from the rpoN region of Escherichia coli (rpoN encodes a σ54). We propose that HprK/P might control the phosphorylation state of HPr and EIIAs, which in turn could control the transcription regulators.
Evaluation of Two-Dimensional Difference Gel Electrophoresis for Protein Profiling
Authors: Gade Dörte , Thiermann Jürgen , Markowsky Dieter , Rabus Ralf
Published: August 2003

Two-dimensional gel electrophoresis (2DE) is a central tool of proteome research, since it allows separation of complex protein mixtures at highest resolution. Quantification of gene expression at the protein level requires sensitive visualization of protein spots over a wide linear range. Two-dimensional difference gel electrophoresis (2D DIGE) is a new fluorescent technique for protein labeling in 2DE gels. Proteins are labeled prior to electrophoresis with fluorescent CyDyes™ and differently labeled samples are then co-separated on the same 2DE gel. We evaluated 2D DIGE for detection and quantification of proteins specific for glucose or N-acetylglucosamine metabolism in the marine bacterium Pirellula sp. strain 1. The experiment was based on 10 parallel 2DE gels. Detection and comparison of the protein spots were performed with the DeCyder™ software that uses an internal standard to quantify differences in protein abundance with high statistical confidence; 24 proteins differing in abundance by a factor of at least 1.5 (t test value <10–9) were identified. For comparison, another experiment was carried out with four SYPRO®-Ruby-stained 2DE gels for each of the two growth conditions; image analysis was done with the ImageMaster™ 2D Elite software. Sensitivity of the CyDye fluors was evaluated by comparing Cy2, Cy3, Cy5, SYPRO Ruby, silver, and colloidal Coomassie staining. Three replicate gels, each loaded with 50 µg of protein, were run for each stain and the gels were analyzed with the ImageMaster software. Labeling with CyDyes allowed detection of almost as many protein spots as staining with silver or SYPRO Ruby.
Annual Incidence of First Silent Stroke in the United States: A Preliminary Estimate
Authors: Leary Megan C. , Saver Jeffrey L.
Published: August 2003

Background: Recent estimates of stroke incidence in the US range from 760,000 to 780,000 annually, however these estimates do not reflect the incidence of silent infarcts and hemorrhages. Since population-based studies indicate the prevalence of silent stroke is substantially higher than that of symptomatic stroke, estimates of stroke incidence based solely on symptomatic events may substantially underestimate the annual stroke burden. Methods: The prevalence of silent infarcts for different age strata were abstracted from two US population-based MRI studies, the Atherosclerosis Risk in Communities Study and the Cardiovascular Health Study. Similarly, first silent cerebral hemorrhage incidence rates were derived from population-based MRI prevalence observations in the Austrian Stroke Prevention Study. Prevalence observations in these studies and death rates from the US Census were inputted to calculate age-specific first silent MRI infarct and hemorrhage incidence. Age- specific incidence rates were projected onto 1998 US population age cohorts to calculate the annual burden of first silent MRI ischemic stroke and first silent MRI cerebral hemorrhage. Results: Estimated age-specific annual incidence rates (per 100,000) of persons experiencing first silent MRI infarct ranged from 1,600 in the age 30–39 stratum to 16,400 at ages 75–79. Estimated incidence rates of first silent MRI cerebral hemorrhage ranged from 180 in the ages 30–39 to 6,900 at age >85. Overall, the projected annual incidence in 1998 of US individuals experiencing first silent MRI infarct was 9,040,000, and first silent MRI hemorrhage 1,940,000. Conclusions: In 1998, more than 11 million persons experienced stroke in the US, in whom approximately 770,000 were symptomatic and 11 million were first-ever silent MRI infarcts or hemorrhages. These findings demonstrate the incidence of stroke is substantially higher than suggested by estimates based solely on clinically manifest events.
Epidemiological and Genetic Studies of Myotonic Dystrophy Type 1 in Taiwan
Authors: Hsiao K.M. , Chen S.S. , Li S.Y. , Chiang S.Y. , Lin H.M. , Pan H. , Huang C.C. , Kuo H.C. , Jou S.B. , Su C.C. , Ro L.S. , Liu C.S. , Lo M.C. , Chen C.M. , Lin C.C.
Published: August 2003

To investigate the prevalence and genetic characteristics of myotonic dystrophy type 1 (DM1) in Taiwan, DM-suspected patients and their families identified during the period of 1990–2001 had their clinical records reevaluated and the CTG repeat sizes at the DM1 locus examined. A total of 96 subjects belonging to 26 families were identified as DM1 patients, which gave a minimal disease prevalence of 0.46/100,000 inhabitants. Clinical anticipation was frequently observed in affected families, even in some parent-child pairs with transmission contraction of the CTG repeat size. The inverse correlation between age at onset and CTG repeat length was significant only in patients with small expansions. In addition, a DM1 carrier with a childhood-onset son was found to have CTG length heterogeneity in the range of 40–50, indicating that premutation alleles could be unstable during gametogenesis as well as in somatic tissues. Our data demonstrated that DM1 is a rare disease in Taiwan and showed that transmission contraction of repeat size is more likely to occur in alleles with large repeats.
X chromosome inactivation: theme and variations
Authors: Migeon B.R.
Published: August 2003

My contribution to this special issue on Vertebrate Sex Chromosomes deals with the theme of X chromosome inactivation and its variations. I will argue that the single active X – characteristic of mammalian X dosage compensation – is unique to mammals, and that the major underlying mechanism(s) must be the same for most of them. The variable features reflect modifications that do not interfere with the basic theme. These variations were acquired during mammalian evolution – to solve special needs for imprinting and locking in the inactive state. Some of the adaptations reinforce the basic theme, and were needed because of species differences in the timing of interacting developmental events. Elucidating the molecular basis for the single active X requires that we distinguish the mechanisms essential for the basic theme from those responsible for its variations.
Spontaneous reactivation of the inactive X chromosome in mouse embryonal carcinoma cells
Authors: Yoshida I.
Published: August 2003

The mouse embryonal carcinoma cell line MC12 carries two X chromosomes, one of which replicates late in S phase and shares properties with the normal inactive X chromosome and, therefore, is considered to be inactivated. Since the hypoxanthine phosphoribosyl transferase (HPRT) gene on the active X chromosome is mutated (Hprt–), MC12 cells lack HPRT activity. After subjecting MC12 cells to selection in HAT medium, however, a number of HAT-resistant clones (HATR) appeared. The high frequency of HAT resistance (3.18 × 10–4) suggested reactivation of Hprt+ on the inactive X chromosome rather than reversion of Hprt–. Consistent with this view, cytological analyses showed that the reactivation occurred over the length of the inactive X chromosome in 11 of 20 HATR clones isolated. The remaining nine clones retained a normal heterochromatic inactive X chromosome. The spontaneous reactivation rate of the Hprt+ on the inactive X chromosome was relatively high (1.34 × 10–6) and comparable to that observed for Xist-deleted somatic cells (Csankovszki et al., 2001), suggesting that the inactivated state is poorly maintained in MC12 cells.
Integrated kinetics of X chromosome inactivation in differentiating embryonic stem cells
Authors: Chaumeil J. , Okamoto I. , Guggiari M. , Heard E.
Published: August 2003

Inactivation of the X chromosome during early female development and the subsequent maintenance of this transcriptionally inert state through countless cell divisions remain a paradigm for epigenetic regulation in mammals. Nevertheless, the exact mechanisms underlying this chromosome-wide silencing process remain unclear. Using differentiating female embryonic stem (ES) cells as a model system, we recently found that histone H3 tail modifications are among the earliest known chromatin changes in the X inactivation process, appearing as soon as Xist RNA accumulates on the X chromosome, but prior to transcriptional silencing of X-linked genes (Heard et al., 2001). In this report we present an integrated analysis of the sequence of early events and chromatin modifications underlying X inactivation in differentiating female ES cells. We have extended our previous analysis concerning changes in histone tail modification states. We find that the hypomethylation of Arg-17 and that of Lys-36 on histone H3 also characterize the inactive X chromosome, and that these profiles show a similarly early onset during the initiation of X inactivation. In addition, we have investigated the kinetics of the shift in replication timing of the X chromosome undergoing inactivation. This event occurs slightly later than Xist RNA coating and the chromatin modifications. Finally, from an early stage in the X inactivation process, characteristic histone modification patterns can be found on the X chromosome at mitosis, suggesting that they represent true epigenetic marks of the inactive state.
Ectopic XIST transcripts in human somatic cells show variable expression and localization
Authors: Chow J.C. , Hall L.L. , Lawrence J.B. , Brown C.J.
Published: August 2003

XIST encodes a functional RNA that is expressed exclusively from the inactive X in female mammals and is required for the silencing of most of the genes on the chromosome. XIST transcripts remain in the nucleus, and their specific localization to the inactive X is important for silencing; however, it is not known how these transcripts localize to the inactive X chromosome. Expression of mouse and human XIST from ectopic sites has suggested that localization to the chromosome from which the gene is expressed may be dependent upon either the copy number of the integrated constructs or the level of ectopic XIST expression. To further examine the behavior of XIST transgenes when expressed from ectopic sites, we introduced an XIST-containing PAC into the human male somatic cell line HT-1080. In five different transformant clones, the degree of localization and associated DNA condensation of the surrounding chromatin varied within nuclei of the same clone, as well as among different clones. Comparing the number of integrated transgenes and the levels of XIST expression revealed that neither factor was sufficient for a tight localization of the XIST signal. Therefore, the extent of expression and localization of XIST transcripts from ectopic transgenes is likely dependent upon many interacting factors, including the number of integrated transgenes, the level of XIST expression, and the site of integration.
Early origins of the X and Y chromosomes: Lessons from tilapia
Authors: Griffin D.K. , Harvey S.C. , Campos-Ramos R. , Ayling L.-J. , Bromage N.R. , Masabanda J.S. , Penman D.J.
Published: August 2003

Differentiated sex chromosome pairs in diverse species display certain common characteristics, normally comprising one largely heterochromatic genetically inactive chromosome and one euchromatic genetically active chromosome (e.g. the mammalian Y and X respectively). It is widely accepted that dimorphic sex chromosomes evolved from homologous pairs of autosomes. Although the exact mechanisms through which the pair diverged are not fully understood, an initial suppression of recombination in the sex-determining region is required by all of the major theories. Here we address the question of the mechanism by which this initial suppression of recombination occurs. Our model postulates that the stochastic, de novo accumulation of heterochromatin in the sex determining region can delay pairing of the sex chromosomes in meiosis, resulting in a decrease in recombination. Data to support this model is presented from the cichlid fish, Oreochromis niloticus. Although such a decrease would in most circumstances be evolutionarily disadvantageous, if the region concerned included the major sex determining gene and other gene(s) with sex-specific functions, then this would be selectively advantageous and could trigger the process(es) which, ultimately, lead to the differentiation of the sex chromosomes.
Cytogenetic studies of Hynobiidae (Urodela)
Authors: Kuro-o M. , Ikebe C. , Izumisawa Y. , Fujinuki Y. , Sasaki K. , Saso K. , Akaba K. , Kohno S.
Published: August 2003

The karyotype of Hynobius tokyoensis (2n = 56) was analyzed using three kinds of banding methods to determine the morphological differentiation of the sex chromosomes of this species. Salamanders and egg sacs were collected from seven localities around Tokyo, Japan. Of 28 chromosome pairs, microchromosome No. 21 was identified as a ZZ/ZW-type sex chromosome. The Z chromosome was acrocentric, whereas the W chromosome was submetacentric, with a heterochromatic, elongated short arm. Interestingly, the W chromosome is of three distinct types, WA, WB, and WC, based on R-banding and Ag-NOR patterns. WA was detected in five populations from southern habitats, whereas WB and WC were detected in one population each from northern habitats. WA, WB, and WC were all found to carry Ag-NORs on their heterochromatic short arms. Considering the karyotypes of other species belonging to the same genus, we discuss the evolution of the sex chromosomes of H. tokyoensis.
Mammalian embryonic development – insights from studies on the X chromosome
Authors: Monk M.
Published: August 2003

This paper reviews our early studies on the cycle of changes of X chromosome activity in different lineages of the developing female mouse embryo. The emphasis is placed on the insights gained into key developmental processes such as the temporal and spatial aspects of developmental totipotency, the timing and cell numbers involved in the origin of the germ line, the molecular mechanisms of genetic deprogramming, reprogramming and X chromosome imprinting, and transgenerational epigenetic inheritance. When viewed in this way, it is quite remarkable to see how much was learned about mammalian development from early studies on the X chromosome. Indeed several paradigm shifts occurred as a result of these studies and these are highlighted in this review.
Z and W chromosomes of chickens: studies on their gene functions in sex determination and sex differentiation
Authors: Mizuno S. , Kunita R. , Nakabayashi O. , Kuroda Y. , Arai N. , Harata M. , Ogawa A. , Itoh Y. , Teranishi M. , Hori T.
Published: August 2003

Since the discovery of SRY/Sry as a testis-determining gene on the mammalian Y chromosome in 1990, extensive studies have been carried out on the immediate target of SRY/Sry and genes functioning in the course of testis development. Comparative studies in non-mammalian vertebrates including birds have failed to find a gene equivalent to SRY/Sry, whereas they have suggested that most of the downstream factors found in mammals including SOX9 are also involved in the process of gonadal differentiation. Although a gene whose function is to trigger the cascade of gene expression toward gonadal differentiation has not been identified yet on either W or Z chromosomes of birds, a few interesting genes have been found recently on the sex chromosomes of chickens and their possible roles in sex determination or sex differentiation are being investigated. It is the purpose of this review to summarize the present knowledge of these sex chromosome-linked genes in chickens and to give perspectives and point out questions concerning the mechanisms of avian sex determination.
The proportion of cells with functional X disomy is associated with the severity of mental retardation in mosaic ring X Turner syndrome females
Authors: Kubota T. , Wakui K. , Nakamura T. , Ohashi H. , Watanabe Y. , Yoshino M. , Kida T. , Okamoto N. , Matsumura M. , Muroya K. , Ogata T. , Goto Y. , Fukushima Y.
Published: August 2003

Turner syndrome females (45,X) do not have mental retardation (MR), whereas some mosaic ring X Turner syndrome females, with 45,X/46,X,r(X), have severe MR. The MR is believed to be caused by a failure of X chromosome inactivation (XCI) of the small ring X chromosome, which leads to functional X disomy (FXD), To explore this hypothesis, we examined the proportion of FXD cells in the peripheral blood of four ring X Turner syndrome females with various levels of MR, using two newly developed XCI assays based on DNA methylation of X-linked genes. As a result, the two patients with extremely severe MR showed complete FXD patterns, whereas the remaining two patients with relatively milder MR showed partial FXD patterns. These results indicate that the proportion of FXD cells may be associated with the severity of MR in mosaic ring X Turner syndrome females, although this association should be confirmed by examining brain cells during development. One of the cases with severe MR and a complete FXD pattern neither lacked the XIST gene nor had uniparental X isodisomy, and we discuss the mechanism of the failure of XCI in this case.
Linkage Analysis of Quantitative Trait Loci in the Presence of Heterogeneity
Authors: Ekstrøm Claus Thorn , Dalgaard Peter
Published: August 2003

Variance component modeling for linkage analysis of quantitative traits is a powerful tool for detecting and locating genes affecting a trait of interest, but the presence of genetic heterogeneity will decrease the power of a linkage study and may even give biased estimates of the location of the quantitative trait loci. Many complex diseases are believed to be influenced by multiple genes and therefore genetic heterogeneity is likely to be present for many real applications of linkage analysis. We consider a mixture of multivariate normals to model locus heterogeneity by allowing only a proportion of the sampled pedigrees to segregate trait-influencing allele(s) at a specific locus. However, for mixtures of normals the classical asymptotic distribution theory of the maximum likelihood estimates does not hold, so tests of linkage and/or heterogeneity are evaluated using resampling methods. It is shown that allowing for genetic heterogeneity leads to an increase in power to detect linkage. This increase is more prominent when the genetic effect of the locus is small or when the percentage of pedigrees not segregating trait-influencing allele(s) at the locus is high.
HSP70 Induced by Hyperosmotic Stress Partially Protects LLC-PK1 Cells against Nephrotoxic Drugs
Authors: Leitão Aurilucia A. , Leite Cleber A. , Santos Bento C. , Boim Mirian A.
Published: August 2003

Accumulation of HSP70 is related to the cytoprotection. It was evaluated whether hyperosmotic stress induces HSP70 accumulation in LLC-PK1 cells, and protects cells against toxicity provoked by cisplatin (Cis) and cyclosporine A (CyA). Cells were maintained in isosmotic (Iso) or hyperosmotic (H) culture medium for 24 h and then exposed to Cis or CyA for an additional period of 12 or 24 h (groups H+Cis and H+CyA). The H medium did not induce cell death and increased both HSP70 mRNA and protein levels, suggesting a role in cell adaptation to H condition. H medium produced partial cytoprotection against Cis and CyA compared with control cells. Despite the cytoprotection, there was a reduction in HSP70 mRNA and protein levels in H+Cis group. In contrast, the H+CyA group presented high levels of HSP70 mRNA and protein. The induction of HSP70 by H medium was associated with tolerance of LLC-PK1 cells against Cis and CyA cytotoxicity but this protection was induced by different mechanisms and depended on the characteristics of the drug used.
Media Exposure to September 11
Authors: Saylor Conway F. , Cowart Brian L. , Lipovsky Julie A. , Jackson Crystal , Finch A. J.
Published: August 2003

This study examined symptoms of Posttraumatic Stress Disorder (PTSD) in children indirectly exposed to September 11 via television, the Internet, and printed media. Approximately 1 month after the attacks, 179 students in Grades K-5 at four Southeastern elementary schools and their parents were surveyed about their experiences and reactions. The Pediatric Emotional Distress Scale (PEDS), the Parent Report of Post-Traumatic Symptoms (PROPS), and the Children's Report of Post-Traumatic Symptoms (CROPS) were used to assess for PTSD symptoms. More PTSD symptoms were reported in children who saw reports on the Internet (vs. television/printed media), saw images of death or injury, or feared that a loved one might have died in the attacks. There was no measurable benefit to seeing heroic or “positive” images. Older children and boys had greater media exposure and more trauma-specific PTSD symptoms. Implications for those striving to deliver appropriate amounts and types of information to children and families following disasters are discussed.
Political Choices and Economic Outcomes
Authors: Heo Uk , Tan Alexander C.
Published: August 2003

South Korea and Taiwan have gone through similar experience of political and economic development in the past several decades. Both countries have achieved miraculous economic developments under the government-led development paradigm and have gone through democratization process in the 1990s. Despite the similarity in developing history, the 1997 financial crisis experiences are quite different between the two countries. South Korea was hit hard by the crisis, whereas the crisis barely touched Taiwan. What caused the difference? The authors argue that the difference in the impacts of the crisis and the resulting outcomes on South Korea and Taiwan is a result of existing political and economic institutions and structures and the choices that were made within those institutions. They support this argument by using institutional explanation, such as growth strategy, market liberalization, and political development.
Reflecting on the Challenges of Preparing Suburban Teachers for Urban Schools
Authors: Chizhik Estella Williams
Published: August 2003

This article shares some of the challenges in preparing suburban preservice teachers at a private college for teaching careers in urban schools. The author describes her challenges as an African American instructor teaching mostly White and female preservice teachers about multicultural issues in urban schools. Many of her preservice teachers resisted some of the issues regarding multicultural education in urban settings. In this article, the author uses qualitative data to explore three possible reasons for preservice teachers' resistance: differing expectations—grappling with students' reactions to the curriculum; pedagogical matters—understanding how teaching practices affect students'resistance; and the culture of power—reflecting on the role the author's ethnicity played in students' reactions to the course. In addition to describing experiences with the multicultural education course, the author provides some possible considerations for administrators and instructors as they prepare suburban preservice teachers for urban teaching environments.
Epic and Tragic Tales
Authors: Brown Andrew D. , Humphreys Michael
Published: August 2003

This interpretive study of change in a U.K.-based college focuses on the divergent understandings of senior managers and two distinct cohorts of their subordinates in a postmerger situation. The authors found that the senior managers told a narrative of epic change, whereas the two subordinate groups both authored recognizably tragic narratives. The research contribution this article makes is threefold. First, they argue that groups' narrations of their working lives both are influenced by psychological processes (such as categorization, self-enhancement, and uncertainty reduction) and draw on broadly available cultural resources (for example, literary genres). Second, they contend that change in organizations is, at least in part, constituted by alterations in people's understandings, encoded in narratives, and shared in conversations. Third, they suggest that group narratives are not merely exercises in sense making but may be hegemonic and have psychic prison effects.
Outpatient Marijuana Treatment for Adolescents
Authors: French Michael T. , Roebuck M. Christopher , Dennis Michael L. , Godley Susan H. , Liddle Howard A. , Tims Frank M.
Published: August 2003

An economic evaluation of five outpatient adolescent treatment approaches (12 total site-by-conditions) was conducted. The economic cost of each of the 12 site-specific treatment conditions was determined by the Drug Abuse Treatment Cost Analysis Program (DATCAP). Economic benefits of treatment were estimated by first monetizing a series of treatment outcomes and then analyzing the magnitude of these monetized outcomes from baseline through the 12-month follow-up. The average economic costs ranged from $90 to $313 per week and from $839 to $3,279 per episode. Relative to the quarter before intake, the average quarterly cost to society for the next 12 months (including treatment costs) significantly declined in 4 of the 12 site-by-treatment conditions, remained unchanged in 6 conditions, and increased in 2 treatment conditions (both in the same site). These results suggest that some types of substance-abuse intervention for adolescents can reduce social costs immediately after treatment.
Sex Offending and Sexual Appetite: The Clinical and Theoretical Relevance of Hypersexual Desire
Authors: Kafka Martin P.
Published: August 2003

Disinhibited sexual desire, clinically manifested as hypersexual desire disorders, can be operationally defined by considering three behavioral domains associated with sexual motivation or appetitive behavior: (a) sexual preoccupation (time/day consumed by fantasies, urges, and activities), (b) the repetitive frequency of enacted sexual behavior (total sexual outlet/week), and (c) adverse consequences associated with repetitive sexual behavior. Data are presented suggesting that clinical samples of males with paraphilias, paraphilia-related disorders, and sexual coercion may be associated with disinhibited sexual appetite. These conditions need to be addressed by an integrated combination of psychotherapeutic and psychopharmacologic interventions that specifically target disinhibited sexual appetitive behaviors, their antecedents, and consequences. Although combination therapies (empirically based specific psychotherapies in conjunction with psychopharmacological treatments) have demonstrated superior efficacy in many Axis I psychiatric disorders, such combination therapies to reduce paraphilias, paraphilia-related disorders, and adult sexual coercion are currently underutilized in both North and South America and Europe.
Differential Pharmacological Treatment of Paraphilias and Sex Offenders
Authors: Hill Andreas , Briken Peer , Kraus Christian , Strohm Kerstin , Berner Wolfgang
Published: August 2003

This article gives an overview of current pharmacological treatment of paraphilias and sex offenders focusing on the situation in Germany. Information about selective serotonin reuptake inhibitors (SSRI) is followed by data about established antihormonal substances (cyproterone acetate/CPA, and medroxyprogesterone acetate/MPA), as well as a more detailed account on luteinizing hormone-releasing hormone agonists (LHRH agonists). The results of open, uncontrolled clinical studies with SSRIs (n = 16) and LHRH agonists (n = 11) in paraphilic outpatients confirm the positive effects of these substances. A survey about the use of CPA and LHRH agonists in forensic hospitals in Germany shows that half of the patients treated with any kind of (anti-) hormonal agents received an LHRH agonist. The authors present a protocol on side effects, contraindications, and monitoring of CPA and LHRH agonists and develop an algorithm for differential pharmacotherapy of paraphilias.
“Difference” in the Police Department
Authors: Garcia Venessa
Published: August 2003

In this article, the author reviews the concept of gender “difference” in relation to the criminal justice system. The author argues that the acceptance of women as different and the practice of doing gender, although initially allowing women entrance into the police organization, has continued to keep women police in subordinate positions and, thus, creates conflict. To illustrate, the author analyzes research on the history of the entrance of women into the police organization as well as their experiences and conflicts. The research reveals that without the acceptance of the doctrine that women are different and more humanistic than men, the police organization might not have accepted the issues of women and children (issues of social service) as police responsibility. However, the continual practice of women police as different has created conflict within the police organization and worked to keep women police within the lower ranks of the organization.
Mapping Dynamic Interaction Patterns in Work Groups
Authors: Wheelan Susan A. , Williams Todd
Published: August 2003

The purpose of this exploratory study is to visually map the dynamics of work groups using a method that emerged from chaos/complexity research. The verbal statements of members of 16 work groups were categorized using the Group Development Observation System. A Wavelet Transform Test was used to produce visual representations of the dynamic interaction patterns in each group's data string. Overall, the patterns that emerged in all 16 groups were similar in shape but different with regard to color, overall tone, and visual clarity. The groups were divided into three tiers based on these visual differences. Significant differences were noted among the tiers. The results support the concept that groups are complex adaptive systems and that the generated images provide a broader perspective of these systems, which may help researchers to explore human groups in more depth.
The Importance of Paternal Warmth
Authors: Veneziano Robert A.
Published: August 2003

Cross-cultural and intra-cultural comparative research into the relationship between paternal behaviors and offspring development has tended to overlook the influence of paternal warmth by assessing only the physical availability of the father or by focusing on parental versus paternal and maternal warmth. Consequently, this article uses comparative methodology to explore the relationship between warm and affectionate paternal behavior and offspring behavior in diverse sociocultural contexts. Results show that paternal physical availability is a much less significant construct for predicting paternal influences on offspring functioning than is paternal warmth and that codes for paternal physical availability are not profitable or beneficial proxies for paternal warmth and affection. Finally, the findings indicate that paternal warmth is often a more significant predictor of youths' functioning than is maternal warmth. These cross-cultural comparative findings are consistent with multivariate studies done in the United States during the last decade.