bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variations in astrocyte and fibroblast response due to biomaterial particulates in vitro
Authors: de Guzman Roche C. , VandeVord Pamela J. 
Published: August 2007

AbstractThe possible involvement of orthopedic biomaterial particles such as cobalt–chrome alloy (Co–Cr), ultrahigh molecular weight polyethylene (UHMWPE), titanium alloy (Ti‐6Al‐4V), and polymethyl methacrylate (PMMA) in the formation of glial and meningeal scars was investigated using an in vitro system. Cell lines were used as models for astrocytes and meningeal fibroblasts. They were incubated with varying concentrations of particle suspensions, after which proliferative and cytotoxic responses were quantified using MTT assay and Live/Dead microscopy. It was determined that relative particulate toxicity (arranged in decreasing order) to astrocytes is Co–Cr > Ti‐6Al‐4V > PMMA > UHMWPE, and toxicity to fibroblasts is PMMA > Co–Cr > Ti‐6Al‐4V > UHMWPE. Cell death caused by PMMA was mainly due to necrosis, while the rest of the particles induced apoptosis. Low quantities of Co–Cr and Ti‐6Al‐4V stimulate increased astrocyte proliferation rate. However, only the cells treated with titanium alloy caused upregulated transcription of reactive astrocyte markers such as glial fibrillary acidic protein, vimentin, nestin, and type IV collagen, suggesting the potential of titanium alloy alone to trigger glial scarring. None of the biomaterials tested promoted proliferation in fibroblasts implying that biomaterial particles are not directly involved in meningeal scar development. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Prey envenomation does not improve digestive performance in western diamondback rattlesnakes (Crotalus atrox)
Authors: McCue Marshall D. 
Published: August 2007

AbstractAlthough the toxic properties of snake venoms have been recognized throughout history, very little is known about the adaptive significance of these powerful mixtures. This study examined the popular hypothesis that prey envenomation enhances digestion by influencing the energetic costs of digestion and assimilation, gut passage time, and apparent assimilation efficiency (ASSIM) in western diamondback rattlesnakes (Crotalus atrox), a species whose venom is recognized for its comparatively high proteolytic activities. A complete randomized block design allowed repeated measures of specific dynamic action and gut passage time to be measured in eight snakes ingesting four feeding treatments (i.e., artificially envenomated live mice, artificially envenomated prekilled mice, saline injected live mice, and saline injected prekilled mice). A second experiment measured ASSIM in eight snakes ingesting a series of six artificially envenomated or six saline injected mice meals over an 8‐week period. Contrary to expectations, the results of both these experiments revealed that envenomation had no significant influence on any of the measured digestive performance variables. Gut passage time averaged 6 days and ASSIM averaged 79.1%. Twenty‐one hours following ingestion, postprandial metabolic rates exhibited factorial increases that averaged 3.9‐fold greater than resting metabolic rate. Specific dynamic action lasted on average 88 hr and accounted for 26% of the total ingested energy. The results of this study reinforce the need to systematically examine the potential adaptive advantages that venoms confer on the snakes that produce them. J. Exp. Zool. 307A:568–577, 2007. © 2007 Wiley‐Liss, Inc.
Gene transfer to the spinal cord neural scar with lentiviral vectors: predominant transgene expression in astrocytes but not in meningeal cells
Authors: Hendriks W. T. J. , Eggers R. , Verhaagen J. , Boer G. J. 
Published: August 2007

AbstractViral vector–mediated overexpression of neurotrophins in cells constituting the neural scar may represent a powerful approach to rendering scar tissue of a central nervous system (CNS) lesion permissive for neuronal regrowth. In this study a lentiviral vector encoding green fluorescent protein (LV‐GFP) was injected in and around the neural scar 2 weeks after a dorsal column lesion in the rat spinal cord in order to analyze transduction characteristics of the neural scar after 4, 7, and 14 days. GFP expression was found at all points after injection and increased from 4 to 7 days, with no apparent difference observed between 7 and 14 days. The core of the lesion was virtually devoid of GFP signal despite direct vector injections in this area. The colocalization of GFP with specific cell markers (GFAP, vimentin, Raldh2, NeuN, OX‐42, ED‐1, and NG‐2) indicated that the predominant cells transduced in the rim of the lesion were astrocytes, with neurons, microglia, oligodendrocyte precursors, and macrophages transduced to a lesser extent. None of the Raldh2‐positive meningeal cells, present in the core of the scar, expressed GFP. In vitro meningeal cells were readily transduced, indicating that in vivo the formation of an extracellular matrix might prevent LV particles from transducing cells in the core of the scar. Because astrocytes are important cellular constituents of the glial scar after CNS injury, transduction of astrocytes with LV vectors encoding neurotrophic factors like BDNF or NT‐3 may be used to enhance regeneration of severed axonal tracts through or along boundaries of a CNS lesion. © 2007 Wiley‐Liss, Inc.
Melatonin prevents brain oxidative stress induced by obstructive jaundice in rats
Authors: Cruz Adolfo , Túnez Isaac , Martínez Rubén , Muñoz‐Castañeda Juan Rafael , Ramírez Luz María , Recio Marta , Ochoa Luís , Arjona Alvaro , Montilla Pedro , Muntané Jordi , Padillo Francisco J. 
Published: August 2007

AbstractThe aim of the study was to analyze the impact of melatonin on brain oxidative stress in experimental biliary obstruction. Cholestasis was done by a double ligature and section of the extrahepatic biliary duct. Melatonin was injected intraperitoneally (500 μg/kg/day). Malondialdehyde (MDA), reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) contents were determined in the brain tissue. Biliary obstruction raised MDA and reduced GSH contents in the cortex, cerebellum, and hypothalamus areas. Moreover, the scavenger enzyme activity significantly dropped in all areas of the brain. Melatonin drastically reduced MDA concentration and enhanced GSH concentration, as well as all antioxidant enzyme activity in all brain areas obtained from the bile duct–ligated animals. In conclusion, the treatment with melatonin decreased lipid peroxidation and recovered the antioxidant status in the brain from cholestatic animals. © 2007 Wiley‐Liss, Inc.
Intrinsic membrane properties and morphological characteristics of interneurons in the rat supratrigeminal region
Authors: Hsiao Chie‐Fang , Gougar Kelly , Asai J. , Chandler Scott H. 
Published: August 2007

AbstractThe membrane properties and morphological features of interneurons in the supratrigeminal area (SupV) were studied in rat brain slices using whole‐cell patch clamp recording techniques. We classified three morphological types of neurons as fusiform, pyramidal, and multipolar and four physiological types of neurons according to their discharge pattern in response to a 1‐sec depolarizing current pulse from −80 mV. Single‐spike neurons responded with a single spike, phasic neurons showed an initial burst of spikes and were silent during the remainder of the stimulus, delayed‐firing (DF) neurons exhibited a slow depolarization and delay to initial spike onset, and tonic (T) neurons showed maintained a discharge throughout the stimulus pulse. In a subpopulation of neurons (10%), membrane depolarization to around −44 mV produced a rhythmic burst discharge (RB) that was associated with voltage‐dependent subthreshold membrane oscillations. Both these phenomena were blocked by the sodium channel blocker riluzole at a concentration that did not affect the fast transient spike. Low doses of 4‐AP, which blocks low‐threshold K+ currents, transformed bursting into low‐frequency tonic discharge. In contrast, bursting occurred with exposure to cadium, a calcium‐channel blocker. This suggests that persistent sodium currents and low‐threshold K+ currents have a role in intrinsic burst generation. Importantly, RB cells were most often associated with multipolar neurons that exhibited either a DF or a T discharge. Thus, the SupV contains a variety of physiological cell types with unique morphologies and discharge characteristics. Intrinsic bursting neurons form a unique group in this region. © 2007 Wiley‐Liss, Inc.
Mechanisms of neurodegenerative diseases: Insights from live cell imaging
Authors: Weissmann Carina , Brandt Roland 
Published: August 2007

AbstractPathologic alterations in protein dynamics such as changes in protein degradation, accumulation of misfolded proteins, and deficits in cellular transport mechanisms are a common feature of most if not all neurodegenerative diseases. Live cell imaging studies promise to contribute to a better understanding of the molecular mechanisms underlying these diseases by visualizing the turnover, accumulation, and transport of proteins in a living cellular context in real time. In this review, we discuss recent work in which different live cell imaging approaches are applied in cellular models of amyotrophic lateral sclerosis, polyQ diseases, and tauopathies as paradigmatic examples of diseases with different types of alterations in protein dynamics. It becomes evident that live cell imaging studies provide new insights into different aspects of protein dynamics, such as the understanding that aggregates are not as static as concluded from previous studies but exhibit a remarkable molecular exchange and that the dynamicity state of the neuronal cytoskeleton might have a critical role in neuronal degeneration. It can be anticipated that live cell imaging studies will lead to a more dynamic view of protein turnover and aggregation, which may aid in identifying drugs that specifically interfere with disease‐related changes. © 2007 Wiley‐Liss, Inc.
Antidepressant drugs reverse the loss of adult neural stem cells following chronic stress
Authors: Hitoshi Seiji , Maruta Noriko , Higashi Mikito , Kumar Akhilesh , Kato Nobumasa , Ikenaka Kazuhiro 
Published: August 2007

AbstractIn rodents, adult neurogenesis occurs in the olfactory bulb and the dentate gyrus of the hippocampus. It has been shown that exposure to psychosocial stress reduces cell proliferation in the dentate gyrus. However, little is known about how stress affects the proliferation kinetics of neural stem cells (NSCs) in the subventricular zone (SVZ), which provide new neurons to the olfactory bulb. We utilized a forced‐swim model of stress in the mouse and found that chronic stress decreased the number of NSCs in the SVZ. The reduction of NSC number persisted for weeks after the cessation of stress but was reversed by treatment with the antidepressant drugs fluoxetine and imipramine. We demonstrated by in vitro colony‐forming neurosphere assay that corticosterone attenuated neurosphere formation by adult NSCs and, in contrast, that serotonin increased the survival of NSCs. In addition, serotonin expanded the size of the NSC pool in the SVZ when it was infused into the lateral ventricle in vivo. These results suggest that, under chronic stress conditions, the number of NSCs is regulated by the actions of glucocorticoids and serotonin. These data provide insights into the molecular mechanisms underlying the pharmacological actions of antidepressant drugs. © 2007 Wiley‐Liss, Inc.
Trends in ship wind speeds adjusted for observation method and height
Authors: Thomas Bridget R. , Kent Elizabeth C. , Swail Val R. , Berry David I. 
Published: August 2007

AbstractGlobally averaged wind speeds from archived ship reports show an increasing trend since the 1940s, which previous studies attributed to the gradual shift from visually estimated to anemometer‐measured winds, and an increase in mean anemometer height. To test this hypothesis, adjustments to account for these changes were applied to individual ship wind observations in the International Comprehensive Ocean–Atmosphere Data Set (ICOADS). Annual means calculated from adjusted reports were compared to reanalysis near‐surface winds in consistently well‐sampled regions for the period 1958–2002.The adjustments to individual ship wind reports for known biases improve the homogeneity over the entire period and remove trends, prior to the early 1980s. However, for the 21‐year period 1982–2002, trends remain in the annual mean spatially averaged adjusted winds, of 0.4 ms−1 decade−1 (6% decade−1) for estimated speeds, and of 0.2 ms−1 decade−1 (3% decade−1) for measured speeds. In contrast, co‐located reanalysis near‐surface wind speeds show little change, 1% decade−1 or less. Anemometers were installed on increasing numbers of ships during the period of study, even as many of these ships continued to report estimated winds. Part of the trend in estimated wind speeds is probably spurious, most likely a result of observers being increasingly influenced by readings from anemometers located well above 10‐m. This influence is indicated by the gradual reduction in the tendency to underestimate nighttime marine winds. Results confirm earlier findings that reanalysis near‐surface winds were biased low. The paper summarizes methods that could be employed to account for remaining inhomogeneities and thereby improve the quality of the marine wind climate record. Copyright © 2007 Crown in the right of Canada. Published by John Wiley & Sons, Ltd
Changes in temperature extremes over Italy in the last 44 years
Authors: Toreti Andrea , Desiato Franco 
Published: August 2007

AbstractChanges in temperature extremes over Italy from 1961 to 2004 were evaluated on the basis of minimum and maximum temperatures measured by 49 synoptic stations uniformly distributed over the country. A set of extreme temperature indices of the Commission for Climatology/Climate Variability and Predictability (CCl/CLIVAR) Working Group on Climate Change Detection was calculated and statistically analysed in order to detect the presence of trends and quantify the variations of the indices for different time periods. Most of the indices, averaged over all stations, show a cooling trend until the end of the 1970s followed by a more pronounced warming trend in the last 25 years. The net variation of the indices reflects an increase in the extremes of the temperature distribution. Among the most significant results, an average increase of 12.3 summer days and 12.4 tropical nights in the overall 44 years are estimated. No significant differences between northern, central and southern Italy are found for most indices, indicating that the trends originate from large‐scale climate features; however, the largest increase of tropical nights is observed at coastal stations. Copyright © 2007 Royal Meteorological Society
Trends in the boreal summer regional Hadley and Walker circulations as expressed in precipitation records from Asia and Africa during the latter half of the 20th century
Authors: Zhao Hongxu , Moore G. W. K. 
Published: August 2007

AbstractWest African summer rainfall, north China summer rainfall and a new climate proxy, snow accumulation from the Dasuopu ice core in the southern Himalaya, have all experienced decreasing trends during the latter half of the 20th century. In this paper, we investigate the existence of a common mechanism that explains these geographically dispersed trends during the boreal summer. In particular, we explore the hypothesis that these trends are related to changes in the regional Hadley and Walker circulations. We show that the divergent circulation in the NCEP reanalysis indicates the existence of trends in these circulations that are consistent with the observed changes in the precipitation records. In addition, the regressions of the divergent circulation in the NCEP reanalysis against these precipitation records indicate that a similar globally coherent signal is associated with the time series and their linear trends while the regressions against the de‐trended residuals do not contain statistically significant large‐scale signals. These similarities lead us to conclude that the decreasing trends in the three precipitation time series during the latter half of the 20th century are consistent with large‐scale changes in the global overturning circulation during the boreal summer. Copyright © 2007 Royal Meteorological Society
Suspended dust over southeastern Mediterranean and its relation to atmospheric circulations
Authors: Dayan Uri , Ziv Baruch , Shoob Tova , Enzel Yehouda 
Published: August 2007

AbstractThe Middle East deserts are often subjected to dust, which reduces horizontal visibility to 5 km, and sometimes even to < 1 km. The present study examines the annual and inter‐annual occurrences of dust events based on 37 years of visibility observations from Hazerim (near Beer Sheba) correlated with PM10 dust concentration. The visibility data was converted to PM10 dust concentration, using concurrent data for three years. We then analyse the linkage between dust and synoptic‐ to global‐scale weather systems.The monthly data indicate that the dust season starts in October and ends in May, with a maximum in March. More than 89% of the total annual dust is accumulated between December and May, the ‘high dust season’. The annual totals vary as much as an order of magnitude from year to year.The synoptic system that produces the majority of the dust over the northern Negev is the Cyprus Low, contributing 2/3 of both the total yearly dust yield and of the number of dust observations. This suggests that a positive relationship exists between the dust in the Negev and rainfall in north Israel, both of which are generated by Cyprus Lows. Indeed, a significant (at 0.05 level) correlation of + 0.30 was found between the two. Correlation maps evidence that in dust‐rich years the cyclonic activity over the Mediterranean is abnormally high and in poor‐dust years it is low. A highly significant negative correlation (−0.66) was found between the dust yield and the intensity of the North Atlantic oscillation (NAO), which modulates the cyclonic activity over Europe and the northern Mediterranean. This may also imply that periods in which more dust accumulated as loess in the northern Negev may indicate the existence of negative NAO phase, and concurrently, warmer conditions over the Sahara, colder conditions over Europe and enhanced rainfall over the Mediterranean Basin. Copyright © 2007 Royal Meteorological Society
Phenological data series of cherry tree flowering in Kyoto, Japan, and its application to reconstruction of springtime temperatures since the 9th century
Authors: Aono Yasuyuki , Kazui Keiko 
Published: August 2007

AbstractChanges in springtime temperature in Kyoto, Japan, since the 9th century were reconstructed, using the phenological data series for cherry tree (Prunus jamasakura), deduced from old diaries and chronicles. Phenological data for 732 years was made available by combining data from previous studies. The full‐flowering date of cherry trees fluctuates in accordance with temperature conditions during February and March. Full‐flowering dates were closely related to the March mean temperature by means of a temperature accumulation index, in which plant growth is considered to be an exponential function of temperature. Calibration enabled accurate estimation of temperatures in the instrumental period, after 1880; the root mean square error (RMSE) of temperature estimates was determined to be within 0.1 °C, after smoothing by local linear regression over time spans of 31 years. The results suggested the existence of four cold periods, 1330–1350, 1520–1550, 1670–1700, and 1825–1830, during which periods the estimated March mean temperature was 4–5 °C, about 3–4 °C lower than the present normal temperature. These cold periods coincided with the less extreme periods, known as the Wolf, Spoerer, Maunder, and Dalton minima, in the long‐term solar variation cycle, which has a periodicity of 150–250 years. The sunspot cycle length, a short‐term solar variation cycle, was also compared with the temperature estimates, with the result that a time lag of about 15 years was detected in the climatic temperature response to short‐term solar variation. Copyright © 2007 Royal Meteorological Society
Urgency assessment in the evaluation of overactive bladder (OAB)
Authors: Starkman Jonathan S. , Dmochowski Roger R. 
Published: August 2007

AbstractOveractive bladder (OAB) is a highly prevalent urinary condition with a profound affect on quality of life. Urinary urgency is the cornerstone symptom that defines OAB and drives all subsequent OAB symptoms. The clinical assessment and measurement of urgency has been limited by its definition, limited understanding of well‐defined pathophysiology, and psychometric measurement properties. This review outlines the important issues relevant to the clinical assessment and measurement scales commonly used to evaluate and measure urinary urgency. This will have important implications toward further understanding and advancing the field of overactive bladder. Neurourol. Urodynam. © 2007 Wiley‐Liss, Inc.
Reduced intensity and non‐myeloablative allogeneic stem cell transplantation in children and adolescents with malignant and non‐malignant diseases
Authors: Satwani Prakash , Morris Erin , Bradley M. Brigid , Bhatia Monica , van de Ven Carmella , Cairo Mitchell S. 
Published: August 2007

AbstractAllogeneic hematopoietic stem cell transplant (AlloSCT) from related or unrelated histocompatible donors has been well established as potentially curative therapy for children and adolescents with selected malignant and non‐malignant diseases. In the malignant setting non‐myeloablative (NMA)/reduced intensity (RI)‐AlloSCT eradicates malignant cells through a graft versus malignancy effect provided by alloreactive donor T‐lymphocytes and/or natural killer cells. In patients with non‐malignant diseases NMA/RI AlloSCT provides enough immunosuppression to promote engraftment and correct underlying genetic defects. In children, myeloablative AlloSCT is not only associated with acute short‐term toxicities but also long‐term late complications such as growth retardation, infertility, and secondary malignancies. NMA/RI‐AlloSCT in children may be associated with reduction in use of blood products, risk of infections, transplant‐related mortality, and length of hospitalization. Despite the success of RI‐AlloSCT in adults, large prospective and/or randomized multicenter studies are necessary in children and adolescent recipients to define the appropriate patient population, optimal conditioning regimens, cost‐benefits, survival and differences in short‐term and long‐term effects compared to conventional myeloablative conditioning. Pediatr Blood Cancer 2008;50:1–8. © 2007 Wiley‐Liss, Inc.