bluuebunny/crossref_metadata_2025_split huggingface dataset:
MEP latency shift after implantation of deep brain stimulation systems in the subthalamic nucleus in patients with advanced Parkinson's disease
Authors: Hidding Ute , Bäumer Tobias , Siebner Hartwig Roman , Demiralay Cüneyt , Buhmann Carsten , Weyh Thomas , Moll Christian , Hamel Wolfgang , Münchau Alexander 
Published: May 2006

AbstractDeep brain stimulation (DBS) into the subthalamic nucleus (STN) is a highly effective treatment for advanced Parkinson's disease (PD). The consequences of STN stimulation on intracortical and corticospinal excitability have been addressed in a few studies using transcranial magnetic stimulation (TMS). Although excitability measurements were compared between the STN stimulation OFF and ON condition, in these experiments, there are no longitudinal studies examining the impact of electrode implantation per se on motor excitability. Here, we explored the effects of STN electrode implantation on resting motor thresholds (RMT), motor evoked potential (MEP) recruitment curves, and MEP onset latencies on 2 consecutive days before and shortly after STN surgery with the stimulator switched off, thus avoiding the effects of chronic DBS on the motor system, in 8 PD patients not taking any dopaminergic medication. After surgery, RMT and MEP recruitment curves were unchanged. In contrast, MEP onset latencies were significantly shorter when examined in relaxed muscles but were unchanged under preactivation. We hypothesize that postoperatively TMS pulses induced small currents in scalp leads underneath the TMS coil connecting the external stimulator with STN electrodes leading to inadvertent stimulation of fast‐conducting descending neural elements in the vicinity of the STN, thereby producing submotor threshold descending volleys. These “conditioning” volleys probably preactivated spinal motor neurons leading to earlier suprathreshold activation by the multiple corticospinal volleys produced by TMS of the motor cortex. These TMS effects need to be considered when interpreting results of excitability measurements in PD patients after implantation of STN electrodes. © 2006 Movement Disorder Society
Expression of the spermatogenic cell‐specific glyceraldehyde 3‐phosphate dehydrogenase (GAPDS) in rat testis
Authors: Welch Jeffrey E. , Barbee Randy R. , Magyar Patricia L. , Bunch Donna O. , O'Brien Deborah A. 
Published: May 2006

AbstractThe spermatogenic cell‐specific variant of glyceraldehyde 3‐phosphate dehydrogenase (GAPDS) has been cloned from a rat testis cDNA library and its pattern of expression determined. A 1,417 nucleotide cDNA has been found to encode an enzyme with substantial homology to mouse GAPDS (94% identity) and human GAPD2 (83% identity) isozymes. Northern blotting of rat tissue RNAs detected the 1.5 kb Gapds transcript in the testis and not in RNA from liver, spleen, epididymis, heart, skeletal muscle, brain, seminal vesicle, and kidney. The rat Gapds mRNA was first detected at day 29 of postnatal testis development, an age which coincides with the initial post‐meiotic differentiation of round spermatids. When isolated rat spermatogenic cell RNA was probed for Gapds expression, transcripts were detected only in round spermatids and condensing spermatids, but not in pachytene spermatocytes, demonstrating haploid expression of the Gapds gene. However, immunohistochemical staining of rat testis sections with anti‐GAPDS antisera did not detect GAPDS in round spermatids, but localized the protein only to stage XIII and later condensing spermatids as well as testicular spermatozoa, indicating that Gapds expression is translationally regulated. The current results are similar to those previously obtained for mouse GAPDS and human GAPD2, suggesting that reliable comparisons can be made between these species in toxicant screening and contraceptive development. Mol. Reprod. Dev. 1052–1060, 2006. Published 2006 Wiley‐Liss, Inc.
Characterization of the mRNA expression of StAR and steroidogenic enzymes in zebrafish ovarian follicles
Authors: Ings Jennifer S. , Van Der Kraak Glen J. 
Published: May 2006

AbstractThe objective of this study was to investigate the levels of expression of steroid biosynthetic enzymes and steroidogenic acute regulatory protein (StAR) at different stages of ovarian follicular development in zebrafish (Danio rerio), and to investigate the sites within the steroid biosynthetic pathway that may be regulated by gonadotropins. Ovarian follicles of sexually mature fish were separated into primary, previtellogenic, vitellogenic, and mature stages and the expression of StAR, P450 side chain cleavage (P450scc), 3β‐hydroxysteroid dehydrogenase (3β‐HSD), P450 hydroxylase/lyase (P450c17), 17β‐hydroxysteroid dehydrogenase type 1 (17β‐HSD1), 17β‐hydroxysteroid dehydrogenase type 3 (17β‐HSD3), and P450 aromatase (P450aromA) was determined by Real time RT‐PCR. The expression of all genes changed significantly as follicles grew, with a decrease in the expression of StAR, P450scc, 3β‐HSD and P450c17 with maturation, and an increase in the expression of 17β‐HSD3 during vitellogenesis and 17β‐HSD1 and P450aromA during previtellogenesis. In vitro incubation of vitellogenic follicles demonstrated that the expression of StAR, 17β‐HSD3, and P450aromA increased in response to hCG, and decreased in the absence of hCG. In contrast, the expression of P450scc, 3β‐HSD, P450c17, and 17β‐HSD1 remained constant between treatments and over time. Testosterone and estradiol production in the culture medium was stimulated by human chorionic gonadotropin (hCG). These experiments aid in the characterization of the roles and regulation of steroids throughout ovarian development, and suggest that gonadotropins play a key role in the regulation of StAR, 17β‐HSD3, and P450aromA in zebrafish. Mol. Reprod. Dev. 943–954, 2006. © 2006 Wiley‐Liss, Inc.
Antioxidant status of the lower oviduct in the chicken varies with age and dietary vitamin E supplementation
Authors: Breque Christelle , Surai Peter , Brillard Jean‐Pierre 
Published: May 2006

AbstractProtection of sperm membranes against lipid peroxidation is a pre‐requisite to prolonged sperm storage, both in vivo and in vitro. As females from avian species can store spermatozoa in the utero‐vaginal junction (UVJ) for prolonged periods, we investigated the mechanisms involved in antioxidative protection of the plasma membrane of chicken sperm in this region. Comparisons of concentrations in nonenzymatic (α‐tocopherol, ascorbic acid, and GSH) and enzymatic (GSH‐Px, SOD) antioxidants among the vagina, UVJ and uterus of sexually mature chicken hens revealed tissue‐specific profiles, with higher ascorbic acid content and increased GSH‐Px and SOD activity in the UVJ compared to other regions of the lower oviduct (vagina, uterus). Deterioration of the antioxidant profile in the UVJ was observed in aging hens, but it was partially compensated by dietary supplementation with vitamin E (130 ppm). It is concluded that the chicken UVJ provides a complex defense barrier against lipid peroxidation of the sperm membrane during in vivo storage, which can be partially improved by dietary supplementation with vitamin E. The protective effects of this barrier decline over time during the reproductive season. Mol. Reprod. Dev. 1045–1051, 2006. © 2006 Wiley‐Liss, Inc.
Sexually dimorphic expression of secreted frizzled‐related (SFRP) genes in the developing mouse Müllerian duct
Authors: Cox Sam , Smith Lee , Bogani Debora , Cheeseman Michael , Siggers Pam , Greenfield Andy 
Published: May 2006

AbstractIn developing male embryos, the female reproductive tract primordia (Müllerian ducts) regress due to the production of testicular anti‐Müllerian hormone (AMH). Because of the association between secreted frizzled‐related proteins (SFRPs) and apoptosis, their reported developmental expression patterns and the role of WNT signaling in female reproductive tract development, we examined expression of Sfrp2 and Sfrp5 during development of the Müllerian duct in male (XY) and female (XX) mouse embryos. We show that expression of both Sfrp2 and Sfrp5 is dynamic and sexually dimorphic. In addition, the male‐specific expression observed for both genes prior to the onset of regression is absent in mutant male embryos that fail to undergo Müllerian duct regression. We identified ENU‐induced point mutations in Sfrp5 and Sfrp2 that are predicted to severely disrupt the function of these genes. Male embryos and adults homozygous for these mutations, both individually and in combination, are viable and apparently fertile with no overt abnormalities of reproductive tract development. Mol. Reprod. Dev. 1008–1016, 2006. © 2006 Wiley‐Liss, Inc.
Spermatocyte responses in vitro to induced DNA damage
Authors: Matulis Shannon , Handel Mary Ann 
Published: May 2006

AbstractSpermatocytes normally sustain many meiotically induced double‐strand DNA breaks (DSBs) early in meiotic prophase; in autosomal chromatin, these are repaired by initiation of meiotic homologous‐recombination processes. Little is known about how spermatocytes respond to environmentally induced DNA damage after recombination‐related DSBs have been repaired. The experiments described here tested the hypothesis that, even though actively completing meiotic recombination, pachytene spermatocytes cultured in the absence of testicular somatic cells initiate appropriate chromatin remodeling and cell‐cycle responses to environmentally induced DNA damage. Two DNA‐damaging agents were employed for in vitro treatment of pachytene spermatocytes: γ‐irradiation and etoposide, a topoisomerase II (TOP2) inhibitor that results in persistent unligated DSBs. Chromatin modifications associated with DSBs were monitored after exposure by labeling surface‐spread chromatin with antibodies against RAD51 (which recognizes DSBs) and the phosphorylated variant of histone H2AFX (herein designated by its commonly used symbol, H2AX), γH2AX (which modifies chromatin associated with DSBs). Both γH2AX and RAD51 were rapidly recruited to irradiation‐ or etoposide‐damaged chromatin. These chromatin modifications imply that spermatocytes recruit active DNA damage responses, even after recombination is substantially completed. Furthermore, irradiation‐induced DNA damage inhibited okadaic acid‐induced progression of spermatocytes from meiotic prophase to metaphase I (MI), implying efficacy of DNA damage checkpoint mechanisms. Apoptotic responses of spermatocytes with DNA damage differed, with an increase in frequency of early apoptotic spermatocytes after etoposide treatment, but not following irradiation. Taken together, these results demonstrate modification of pachytene spermatocyte chromatin and inhibition of meiotic progress after DNA damage by mechanisms that may ensure gametic genetic integrity. Mol. Reprod. Dev. 1061–1072, 2006. © 2006 Wiley‐Liss, Inc.
Steroid hormones acutely regulate expression of a nudix protein‐encoding gene in the endometrial epithelium of sheep
Authors: Ing Nancy H. , Wolfskill Rebecca L. , Clark Shauna , deGraauw Jennifer A. , Gill Clare A. 
Published: May 2006

AbstractSteroid hormones regulate endometrial gene expression to meet the needs of developing embryos. Our hypothesis is that steroid hormones transiently induce expression of genes in the endometrial epithelium to make the uterine environment different between the earliest days of pregnancy. We identified one such gene product using differential display‐polymerase chain reactions. The gene product that was strongly induced in ewes between day 3 and 6 of the estrous cycle was cloned and sequenced to identify it as encoding a member of the Nudix family of hydrolase enzymes. Northern blot analyses indicated that NUDT16 mRNA concentrations were elevated 10‐fold in the endometrium of sheep from day 5 to 9 of the estrous cycle and returned to basal levels by day 11. In assays of RNA samples from 15 different tissues from an adult ewe, the concentrations of NUDT16 mRNA were greatest in endometrium. In situ hybridization localized NUDT16 mRNA exclusively to the endometrial epithelial cells of the glands and uterine lumen. In ovariectomized ewes, NUDT16 mRNA was induced by a regimen of alternating estrogen and progesterone therapy designed to mimic the hormonal experiences of a ewe at day 6 of the estrous cycle. The final estrogen treatment in the regimen was critical to the expression of NUDT16 as well as progesterone receptor and estrogen receptor‐β genes. Characterization of the NUDT16 gene identified putative steroid hormone response elements, which can now be investigated to understand its unique pattern of regulation in the earliest days of pregnancy. Mol. Reprod. Dev. 967–976, 2006. © 2006 Wiley‐Liss, Inc.
Culturing in vitro produced blastocysts in sequential media promotes ES cell derivation
Authors: Liu J. , Schoonjans L. , Tielens S. , Speleman F. , Cornelissen M. , De Sutter P. , Dhont M. , Van der Elst J. 
Published: May 2006

AbstractEmbryonic stem (ES) cell lines are routinely derived from in vivo produced blastocysts. We investigated the efficiency of ES cells derivation from in vitro produced blastocysts either in monoculture or sequential culture. Zygotes from hybrid F1 B6D2 mice were cultured in vitro to the blastocyst stage in Potassium (K+) simplex optimised medium (KSOM) throughout or in KSOM and switched to COOK blastocyst medium on day 3 (KSOM–CBM). Blastocysts were explanted on a feeder layer of mitomycin C‐inactivated murine embryonic fibroblasts (MEF) in TX‐WES medium for ES cell derivation. Sequential KSOM–CBM resulted in improved blastocyst formation compared to KSOM monoculture. ES cells were obtained from 32.1% of explanted blastocsyts cultured in KSOM–CBM versus18.4% in KSOM alone. ES cell lines were characterized by morphology, expression of SSEA‐1, Oct‐4 and alkaline phosphatase activity, and normal karyotype. These results indicate that in vitro culture systems to produce blastocysts can influence the efficiency of ES cell line derivation. Mol. Reprod. Dev. 1017–1021, 2006. © 2006 Wiley‐Liss, Inc.
Addition of glutathione or thioredoxin to culture medium reduces intracellular redox status of porcine IVM/IVF embryos, resulting in improved development to the blastocyst stage
Authors: Ozawa Manabu , Nagai Takashi , Fahrudin Mokhamad , Karja Ni Wayan Kurniani , Kaneko Hiroyuki , Noguchi Junko , Ohnuma Katsuhiko , Kikuchi Kazuhiro 
Published: May 2006

AbstractThe present series of experiments investigated the effect of a reducing environment created by addition of reduced glutathione (GSH) or thioredoxin (TRX) to in vitro culture medium on the developmental competence of in vitro produced porcine embryos, and their intracellular redox status. Porcine cumulus–oocyte complexes were collected from ovaries matured and fertilized in vitro. The putative zygotes were then cultured for 6 days in modified NCSU‐37 medium with or without (control) GSH or TRX, and their developmental competence was evaluated. In addition, the intracellular redox status of the cultured embryos was compared quantitatively using an index based on the ratio of the intracellular GSH content relative to the intracellular H2O2 level. The proportion of embryos that developed to the blastocyst stage was significantly increased when 0.5 or 1.0 µM GSH (29.6% or 30.4%, P < 0.05 or 0.01, respectively) or 1.0 mg/ml TRX (30.6%, P < 0.01) was added to the medium compared to that without any supplementation (control; 20.1%). The intracellular redox status of embryos at the 8‐ to 12‐cell stage or the blastocyst stage in the group cultured in the presence of GSH or TRX was significantly reduced in comparison with the control (P < 0.05 to 0.001). Furthermore, administration of GSH or TRX enhanced the total cell number (from 48.3 to 49.2) and lowered the proportion of apoptotic cells (from 6.2% to 7.0%) in blastocysts compared with the control (cell number 39.3; apoptosis rate 11.1%, P < 0.05). These results suggest that GSH or TRX can improve the in vitro development of porcine embryos, while maintaining an intracellular reductive status. Mol. Reprod. Dev. 998–1007, 2006. © 2006 Wiley‐Liss, Inc.
A difference scheme for a parabolic system modelling the thermoelastic contacts of two rods
Authors: Sun Zhi‐zhong , Zhao Lei , Li Fu‐Le 
Published: May 2006

AbstractIn this article, we study a sequence of finite difference approximate solutions to a parabolic system, which models two dissimilar rods that each rod is fixed at one end and is free to expand or contact at the other end. A finite difference scheme is derived by the method of reduction of order on nonuniform mesh. The unique solvability, unconditional stability, and convergence of the difference scheme are proved. The convergence order is of order two in both time and space. The convergence of iterative algorithm for the difference scheme are also discussed. A numerical example is presented to demonstrate the theoretical results. © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2007
Cribra orbitalia and porotic hyperostosis in a Greek colonial population (5th to 3rd centuries BC) from the Black Sea
Authors: Keenleyside A. , Panayotova K. 
Published: May 2006

AbstractCribra orbitalia and porotic hyperostosis in Greek skeletal remains have typically been attributed to a genetic anaemia, most notably thalassemia due to the presence of endemic malaria in the Mediterranean region. This paper reports the results of an analysis of cribra orbitalia and porotic hyperostosis in a Greek colonial population (5th to 3rd centuries BC) from the Black Sea. Archaeological evidence, stable isotopic data, and other skeletal indicators of physiological stress are examined to determine the most likely cause(s) of these lesions. While the possibility that some of the colonists of Apollonia suffered from thalassemia cannot be entirely discounted, the skeletal evidence examined in this study is not consistent with a diagnosis of thalassemia. We must therefore be cautious in assuming that cribra orbitalia and porotic hyperostosis in Greek skeletal remains, and indeed skeletal remains from any region where malaria was endemic in the past, is always indicative of this condition. Nutritional deficiencies and exposure to infectious diseases probably played an equally, if not more, important role in the development of these lesions. Copyright © 2006 John Wiley & Sons, Ltd.
Online learning: The potential for occupational therapy education
Authors: Hollis Vivien , Madill Helen 
Published: May 2006

AbstractOnline learning continues to have a significant impact on higher education. Increasingly students seek a combination of online learning and face‐to‐face instruction at undergraduate and graduate levels and occupational therapists ask for online continuing professional development opportunities. However, occupational therapy educators have been slow to adopt web‐based instructional technology. This paper presents background information on the use of web‐based learning in the general sphere of higher education and outlines the current range of usage in occupational therapy education. Research findings are presented to stimulate discussion regarding online learning and occupational therapy professional socialisation, student satisfaction and outcomes. There is a fine line between full and partial online course delivery, so research on technology‐enhanced campus‐based delivery is also included in the review. Evidence suggests that blending combinations of technologies with computer mediated learning enhances interaction and could address the higher order learning needs of professional programmes such as occupational therapy. Copyright © 2006 John Wiley & Sons, Ltd.
Engagement in occupations among men and women with schizophrenia
Authors: Bejerholm Ulrika , Eklund Mona 
Published: May 2006

AbstractThis study describes engagement in daily occupations of 10 women and 10 men with schizophrenia. A 24‐hour diary of time use and interview were used and analysed by content analysis. Three levels of occupational engagement were identified; (1) mainly disengaged throughout the day, (2) disengaged during some part of the day, and (3) largely engaged in occupations during the day. Each level of occupational engagement was related to a daily rhythm and a sense of meaning. The results of the content analysis showed that levels of engagement ranged from performing mostly quiet activities, alone, with little sense of meaning, to engaging in meaningful occupations that involved social interactions. In general female participants preferred activities in their home environment while males preferred activities outside their home environment. Although this study was limited by geographic and cultural boundaries, as well by the sample size, the results showed that being diagnosed as having schizophrenia does not necessarily mean having an impoverished lifestyle. Thus, it is important for occupational therapists to identify these variations in engagement in order to have a realistic point of departure in the evaluation process and in forming a therapeutic alliance with the client. In future research, methods need to be developed that can gather extensive information on how occupational engagement is related to health and well‐being in individuals diagnosed with schizophrenia. Copyright © 2006 John Wiley & Sons, Ltd.
Screening in early pregnancy for pre‐eclampsia using down syndrome quadruple test markers
Authors: Wald Nicholas J. , Morris Joan K. , Ibison Judith , Wu Tiesheng , George Lynne M. 
Published: May 2006

AbstractObjectivesTo estimate the screening performance of early second‐trimester prenatal serum markers for Down syndrome, in screening for the development of pre‐eclampsia, and analyse the uncertainty over its screening performance.MethodsA nested case‐control study was carried out on 96 women with pre‐eclampsia and 5 controls for each case from among the women attending three hospitals in London for their prenatal care. Record linkage between computerized obstetric and screening databases identified women with pre‐eclampsia and unaffected control women. The stored frozen serum samples collected from these pregnancies between 15 and 22 weeks' gestation were retrieved and assayed for α‐fetoprotein (AFP), unconjugated estriol (uE3), total human chorionic gonadotrophin (hCG), free β‐hCG and inhibin‐A.ResultsPre‐eclampsia was identified from the computerized obstetric records and confirmed by examination of the medical notes. In the pregnancies that went on to develop pre‐eclampsia, early second trimester inhibin‐A and hCG values were significantly raised and uE3 values were significantly lowered, while AFP values were not significantly altered. Using the Quadruple test markers (AFP, uE3, hCG (total or free β) and inhibin‐A), an estimated 34% of pregnancies that developed pre‐eclampsia were detected at a 5% false‐positive rate. If all the women who had pre‐eclampsia in a previous pregnancy (assuming a pre‐eclampsia prevalence of 4%) are considered as screen positive and the serum test is applied to the remaining women, then around 42% of pre‐eclamptic pregnancies would be detected at a 6.5% false‐positive rate. Pre‐eclampsia screening performance using the Quadruple test markers was materially better than that using the Triple test markers.ConclusionAdding screening for pre‐eclampsia to an existing Down syndrome screening programme using the Quadruple test markers is simple and worthwhile. It will detect over 40% of pregnancies with pre‐eclampsia at an acceptable false‐positive rate (about 6%) and with minimal additional costs. Copyright © 2006 John Wiley & Sons, Ltd.