bluuebunny/crossref_metadata_2025_split huggingface dataset:
Progenitor cells from the CA3 region of the embryonic day 19 rat hippocampus generate region‐specific neuronal phenotypes in vitro
Authors: Shetty Ashok K. 
Published: April 2004

AbstractProgenitor cells that endure in different regions of the CNS after the initial neurogenesis can be expanded in culture and used as a source of donor tissue for grafting in neurodegenerative diseases. However, the proliferation and differentiation characteristics of residual neural progenitor cells from distinct regions of the CNS are mostly unknown. This study elucidated the characteristics of progenitor cells that endure in the CA3 region of the hippocampus after neurogenesis, by in vitro analyses of cells that are responsive to epidermal growth factor (EGF) or fibroblast growth factor‐2 (FGF‐2) in the embryonic day 19 (E19) rat hippocampus. Isolated cells from the E19 CA3 region formed neurospheres in the presence of either EGF or FGF‐2, but the yield of neurospheres was greater with FGF‐2 exposure. Differentiation cultures revealed a greater yield of neurons from FGF‐2 neurospheres (60%) than from EGF neurospheres (35%). Exposure to brain‐derived neurotrophic factor (BDNF) enhanced the yield of neurons from EGF neurospheres but had no consequence on FGF‐2 neurospheres. A large number of neurons from EGF/FGF‐2 neurospheres demonstrated clearly palpable morphological features of CA3 pyramidal neurons and lacked γ‐aminobutyric acid (GABA) expression. However, a fraction of neurons (17–20%) from EGF/FGF‐2 neurospheres expressed GABA, and exposure to BDNF increased the number of GABAergic neurons (30%) from EGF neurospheres. Neurons from EGF/FGF‐2 neurospheres also contained smaller populations of calbindin‐ and calretinin‐positive interneuron‐like cells. Thus, progenitor cells responsive to FGF‐2 are prevalent in the CA3 region of the E19 rat hippocampus and give rise to a greater number of neurons than progenitor cells responsive to EGF. However, both FGF‐2‐ and EGF‐responsive progenitor cells from E19 CA3 region are capable of giving rise to CA3 field‐specific phenotypic neurons. These results imply that progenitor cells that persist in the hippocampus after neurogenesis remain regionally restricted and hence retain their ability to give rise to region‐specific phenotypic neurons even after isolation and expansion in vitro. © 2004 Wiley‐Liss, Inc.
Neuronal number, volume, and apoptosis of the left dentate gyrus of chronically stressed pigs correlate negatively with basal saliva cortisol levels
Authors: van der Beek Eline M. , Wiegant Victor M. , Schouten Willem G.P. , van Eerdenburg Frank J.C.M. , Loijens Leanne W.S. , van der Plas Carianne , Benning Marjan A. , de Vries Hester , de Kloet E. Ron , Lucassen Paul J. 
Published: April 2004

AbstractAlthough the consequences of stress and hypercortisolemia for the rodent hippocampal dentate gyrus (DG) are well known, little is known about other species. For pigs, tethered housing represents a well‐established chronic stressor that shares many similarities with restraint paradigms, as evidenced by profound changes in behavior and autonomic and endocrine dysfunction, including flattened cortisol rhythms and hypercortisolemia—all conditions that may threaten hippocampal viability in rat. Here, we studied structural parameters of the porcine DG after 5 months of tethered housing in relation to basal saliva cortisol measured antemortem. We further investigated whether any neuropathology or alterations in apoptosis had occurred in the left hippocampal hemisphere. Stereological analysis revealed high correlations between DG volume and neuron number in individual animals in both hemispheres. Within individual animals, neuron numbers of the left and right lobes were not correlated. Notably, basal cortisol was negatively correlated with volume and neuron number of the left, but not the right DG. Although obvious neuropathology was absent, apoptosis was present in DG and alveus and less so in CA areas. Despite the short window of time during which apoptosis is detectable, their stereologically estimated numbers in the DG, but not in other regions, were negatively correlated with cortisol. In conclusion, our data indicate for the first time a profound lateralization in the relationship between DG structure, apoptosis, and basal cortisol after stress in pigs. Five months of chronic stress failed to induce lasting neuropathology. Although accumulating changes in apoptosis could have contributed to the structural DG alterations, further studies should reveal whether stress has been instrumental, or whether the differences between animals were present from birth onward. The present lateralization after stress is, however, consistent with lateralized hippocampal volume changes in stress‐related human disorders and suggests that these effects are not limited to this species alone. © 2004 Wiley‐Liss, Inc.
Intrahippocampal administration of BDNF in adult rats affects short‐term behavioral plasticity in the Morris water maze and performance in the elevated plus‐maze
Authors: Cirulli Francesca , Berry Alessandra , Chiarotti Flavia , Alleva Enrico 
Published: April 2004

AbstractThe present study evaluated the effects of a single intrahippocampal administration of brain‐derived neurotrophic factor (BDNF) on memory retention in a water maze. Adult rats were trained in a water maze (acquisition phase, day 1). Immediately after the last training trial subjects were injected in the right hippocampus with either BDNF (24 μg) or phosphate‐buffered saline (1 μl). On day 2, all subjects were tested for memory retention in a probe trial and were subsequently tested for reversal learning. While no differences emerged in the probe trial, BDNF‐treated subjects showed a shorter latency and a shorter path length to reach the platform during the reversal phase. A significant difference in their “turn angle” and in their swim paths suggests that they might have used a different search strategy compared with controls. Moreover, all subjects also underwent an elevated‐plus maze test. BDNF‐treated‐animals showed a clear tendency to spend a greater amount of time in the open arms and a significantly higher frequency of grooming behavior and of the stretched‐attend posture in this maze area, but no differences in locomotion. Overall, these results indicate that administration of BDNF improves performance in a spatial memory task and has enduring effects on emotional behavior. © 2004 Wiley‐Liss, Inc.
Distribution of metabotropic GABA receptor subunits GABAB1a/b and GABAB2 in the rat hippocampus during prenatal and postnatal development
Authors: López‐Bendito Guillermina , Shigemoto Ryuichi , Kulik Akos , Vida Imre , Fairén Alfonso , Luján Rafael 
Published: April 2004

AbstractMetabotropic γ‐aminobutyric acid receptors (GABAB) play modulatory roles in central synaptic transmission and are involved in controlling neuronal migration during development. We used immunohistochemical methods to elucidate the expression pattern as well as the cellular and the precise subcellular localization of the GABAB1a/b and GABAB2 subunits in the rat hippocampus during prenatal and postnatal development. At the light microscopic level, both GABAB1a/b and GABAB2 were expressed in the hippocampal primordium from embryonic day E14. During postnatal development, immunoreactivity for GABAB1a/b and GABAB2 was distributed mainly in pyramidal cells, with discrete GABAB1a/b‐immunopositive cell bodies of interneurons present throughout the hippocampus. Using double immunofluorescence, we demonstrated that during the second week of postnatal development, GABAB1a/b but not GABAB2 was expressed in glial cells throughout the hippocampal formation. At the electron microscopic level, GABAB1a/b and GABAB2 showed a similar distribution pattern during postnatal development. Thus, at all ages the two receptor subunits were located postsynaptically in dendritic spines and shafts at extrasynaptic and perisynaptic sites in both pyramidal and nonpyramidal cells. We further demonstrated that the two subunits were localized presynaptically along the extrasynaptic plasma membrane of axon terminals and along the presynaptic active zone in both asymmetrical and, to a lesser extent, symmetrical synapses. These results suggest that GABAB receptors are widely expressed in the hippocampus throughout development and that GABAB1a/b and GABAB2 form both pre‐ and postsynaptic receptors. © 2004 Wiley‐Liss, Inc.
Vascular adventitia generates neuronal progenitors in the monkey hippocampus after ischemia
Authors: Yamashima Tetsumori , Tonchev Anton B. , Vachkov Ivan H. , Popivanova Boryana K. , Seki Tatsunori , Sawamoto Kazunobu , Okano Hideyuki 
Published: April 2004

AbstractIn the adult hippocampus, neurogenesis proceeds in the subgranular zone (SGZ) of the dentate gyrus (DG), but not in the cornu Ammonis (CA). Recently, we demonstrated in monkeys that transient brain ischemia induces an increase of the neuronal progenitor cells in the SGZ, but not in CA1, in the second week after the insult. To identify the origin of primary neuronal progenitors in vivo, we compared the postischemic monkey DG and CA1, using light and electron microscopy, focusing on specific phenotype markers, as well as the expression of neurotrophic factors. Laser confocal microscopy showed that 1–3% of 5‐bromo‐2′‐deoxyuridine (BrdU)‐positive cells in the SGZ after 2–96 h labeling were also positive for neuronal markers such as TUC4, βIII tubulin, and NeuN on days 9 and 15. In contrast, despite the presence of numerous BrdU‐positive cells, CA1 showed no neurogenesis at any time points, and all the progenitors were positive for glial markers: Iba1 or S‐100β on days 4, 9, and 15. Highly polysialylated neural cell adhesion molecule (PSA‐NCAM)‐positive cells were abundant in the SGZ, but were absent in CA1. On day 9, most of the immature neurons positive for βIII‐tubulin in SGZ showed an increase in PSA‐NCAM immunoreactivity. The immunoreactivity of brain‐derived neurotrophic factor (BDNF) was abundant at the vascular adventitia of the SGZ, but was absent at the adventitia of CA1. BrdU‐positive progenitor cells were frequently seen in the vicinity of proliferating blood vessels. Ultrastructural analysis indicated that most of the neuronal progenitor cells and microglia originated from the pericytes of capillaries and/or adventitial cells of arterioles (called vascular adventitia). The detaching adventitial cells showed mitotic figures in the perivascular space, and the resultant neuronal progenitor cells made contact with dendritic spines associated with synaptic vesicles or boutons. These data implicate the vascular adventitia as a novel potential source of neuronal progenitor cells in the postischemic primate SGZ. © 2004 Wiley‐Liss, Inc.
Fos induction and persistence, neurodegeneration, and interneuron activation in the hippocampus of epilepsy‐resistant versus epilepsy‐prone rats after pilocarpine‐induced seizures
Authors: Fabene Paolo F. , Andrioli Anna , Priel Margareth R. , Cavalheiro Esper A. , Bentivoglio Marina 
Published: April 2004

AbstractPrevious studies demonstrated that the spiny rat Proechimys guyannensis exhibits resistance to experimental epilepsy. Neural activation was studied in the Proechimys hippocampus, using Fos induction, within 24 h after pilocarpine‐induced seizures; neurodegenerative events were investigated in parallel, using FluoroJade B histochemistry. These parameters were selected since pilocarpine‐induced limbic epilepsy is known to elicit immediate early gene expression and cell loss in the hippocampus of seizure‐prone laboratory rodents. At variance with matched experiments in Wistar rats, pilocarpine injection resulted in Proechimys in seizure episodes that, as previously reported, did not develop into status epilepticus. At 3 h and 8 h after seizure onset, Fos immunoreactivity filled the dentate gyrus of both rat species, and was quite marked in pyramidal cells of the Proechimys Ammon's horn. At 24 h, Fos immunoreactivity dropped in the Wistar hippocampus and persisted in Proechimys. At 8 h and 24 h, FluoroJade‐stained neurons were very few in the Proechimys hippocampus, whereas they were abundant in that of Wistar rats. Double immunohistochemistry for Fos and parvalbumin, the protein expressed by fast‐spiking hippocampal interneurons, indicated that Fos was induced up to 24 h in the vast majority of parvalbumin‐containing cells of the Proechimys hippocampus, and in a minority of these cells in the Wistar hippocampus. The findings demonstrate that early postepileptic neurodegeneration is very limited in the Proechimys hippocampus, in which sustained Fos induction persists for several hours. The findings also indicate that Fos induction and persistence may not correlate with seizure intensity and may not be associated with neuronal death. Finally, the data implicate differential mechanisms of interneuron activity in anti‐convulsant and pro‐convulsant phenomena. © 2004 Wiley‐Liss, Inc.
Epidemiology Of Hodgkin's disease: a review
Authors: Cartwright R. A. , Watkins Gillian 
Published: April 2004

AbstractThe descriptive and aetiological epidemiology of Hodgkin's Disease (HD) are reviewed. Key issues which are highlighted include the evidence suggesting that HD is a complex of related conditions that are part mediated by infectious diseases, immune deficits and genetic susceptibilities. There is little convincing evidence to suggest any other environmental factors are involved in the aetiology. The apparent changing pattern of disease by time and from country to country, needs careful future study. Copyright © 2004 John Wiley & Sons, Ltd.
Repair of calvarial defects in rats by prefabricated hydroxyapatite cement implants
Authors: Schliephake H. , Gruber R. , Dard M. , Wenz R. , Scholz S. 
Published: April 2004

AbstractThe aim of the present study was to test the hypothesis that calvarial defects can be repaired by using preformed implants of calcium phosphate bone cement (CPBC) in rats. Sixty adult female Sprague–Dawley rats received full‐thickness calvarial nonhealing defects with a diameter of 8 mm. Three different CPBCs were used: group 1: tetracalcium phosphate‐based powder; group 2: a blend of amorphous and crystalline calcium phosphate precursors; and group 3: an alpha‐tricalcium phosphate (α‐TCP)‐based powder. Implants were left to cure for 25–40 min at room temperature in a silicon mold of 7.9 mm and inserted press fit into the defects. Fifteen animals served as unfilled controls. After 13, 26, and 52 weeks, the material was analyzed qualitatively by using surface‐stained undecalcified thick‐section specimens and quantitatively by using semiautomated histometry. Kruskal–Wallis tests were applied to compare mean values of periimplant bone formation at a significance level of p < 0.05. Three implants of group 1 fractured during insertion. Resorption of CPBC without complementary bone formation was noticed in these implants. Unfractured implants were resorbed with simultaneous apposition of bone on the implant surface. After 52 weeks, the resorption rate varied between 23.1 and 39.3%. Periimplant bone formation increased continuously on average around all implant types, but it reached statistical significance only in group 2. The results showed that repair of calvarial defects can be achieved by preformed CPBC implants. The rate of resorption of preformed implants is, however, much lower than that reported for in vivo cured CPBC. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 69A: 382–390, 2004
Protein‐coated poly(L‐lactic acid) fibers provide a substrate for differentiation of human skeletal muscle cells
Authors: Cronin Elizabeth M. , Thurmond Frederick A. , Bassel‐Duby Rhonda , Williams R. Sanders , Wright Woodring E. , Nelson Kevin D. , Garner Harold R. 
Published: April 2004

AbstractTissue engineering represents a potential method for repairing damaged skeletal muscle tissue. Extracellular matrix (ECM) proteins were evaluated for their ability to aid in cell attachment, whereas a poly(L‐lactic acid) (PLLA) fiber scaffold was tested as a substrate for the differentiation of human skeletal muscle cells. In comparison to uncoated or gelatin‐coated PLLA films, cell attachment increased significantly (p < 0.001) on PLLA films coated with ECM gel, fibronectin, or laminin. Myoblasts differentiated into multinucleated myofibers on ECM gel‐coated PLLA fibers, and expressed muscle markers such as myosin and α‐actinin. Oligonucleotide microarray analysis showed similar gene expression profiles for human skeletal muscle cells on ECM gel‐coated PLLA fibers as to that observed for myofibers on tissue culture plates. Therefore, PLLA fibers coated with ECM proteins provide a scaffold for the development of skeletal muscle tissue for tissue engineering and cell transplantation applications. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 69A: 373–381, 2004
Quantifying the effect of resin type and sterilization method on the degradation of ultrahigh molecular weight polyethylene after 4 years of real‐time shelf aging
Authors: Willie Bettina M. , Ashrafi Shadi , Alajbegovic Sanjin , Burnett Trever , Bloebaum Roy D. 
Published: April 2004

AbstractAlternative sterilization methods including ethylene oxide, gas plasma, and gamma‐radiation in an inert environment were implemented in the late 1990s, to limit oxidative degradation of ultrahigh molecular weight polyethylene (PE). There was also a simultaneous transition to PE resins that did not contain calcium stearate. Shelf storage duration of PE inserts following gamma‐irradiation in air has been correlated to poor clinical performance and increased wear. This study aimed to determine how sterilization method and resin type influenced degradation of PE after 4 years of real‐time shelf aging. It was hypothesized that gamma‐irradiation and stearate containing resins would incur significantly more degradation than nonradiated, stearate‐free resins. Gamma‐irradiated PE samples in air and nitrogen had a significantly increased density and oxidation index, compared to nonirradiated PE after 4 years of shelf aging. Alternative sterilization methods such as ethylene oxide and gas plasma appeared to have significantly less oxidation regardless of PE resin type. A partial correlation demonstrated that density and oxidation index were not correlated (r2 = 0.079) when examining the influence of sterilization method. The data supported that after 4 years of real‐time shelf aging, the type of sterilization method had a larger influence on PE degradation than resin type. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 69A: 477–489, 2004
Molecular release from a polymeric microreservoir device: Influence of chemistry, polymer swelling, and loading on device performance
Authors: Grayson Amy C. Richards , Cima Michael J. , Langer Robert 
Published: April 2004

AbstractA polymeric microreservoir device for controlled‐release drug delivery relies on the degradation of thin poly(lactic‐co‐glycolic acid) membranes that seal each reservoir to achieve pulsatile drug delivery. In vitro release studies in which the swelling of the reservoir membranes was measured indicate a correlation between the release times of various radiolabeled molecules from the devices and the time at which the maximum membrane swelling was observed. Varying the chemistry (lipophilicity/hydrophilicity) or molecular weight of the molecules loaded into the devices did not appear to affect the degree of membrane swelling that was observed, or the time at which the molecules were released from the devices. The amount of drug that was loaded into the reservoirs also did not appear to affect the observed release time of the drug from the device, a significant departure from the behavior of many matrix‐type polymeric drug delivery systems. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 69A: 502–512, 2004
Selective protein adsorption and blood compatibility of hydroxy‐carbonate apatites
Authors: Takemoto Shinji , Kusudo Yuko , Tsuru Kanji , Hayakawa Satoshi , Osaka Akiyoshi , Takashima Seisuke 
Published: April 2004

AbstractWe examined the blood compatibility and protein adsorption on hydroxyapatite and hydroxy‐carbonate apatite. Those apatites were synthesized under a 0, 5, or 15% CO2‐containing N2 atmosphere by a wet‐chemical method with a strong ammonia alkali solution of calcium nitrate and diammonium hydrogen phosphate (5:3 in molar ratio) and subsequent calcination in the range of 105–700°C. From infrared (IR) analysis, the carbonate ions substituted both phosphate ions and hydroxyl ions in the hydroxyapatite lattice; the intensities of IR bands assignable to phosphate ions and hydroxyl ions were reduced on calcinations. The specific surface areas of synthesized apatites decreased with increasing calcination temperature. Blood‐clotting properties were evaluated in terms of active partial thromboplastin time, prothrombin time, and the amount of fibrinogen for the plasma in contact with the apatites, indicating that all the apatites barely influenced the blood clotting system. The apatites were in contact with a solution containing both bovine serum albumin (BSA) and β2‐microglobulin (β2‐MG), and the amounts of those proteins adsorbed on them were examined: the amount of absorbed BSA and β2‐MG gradually increased with the calcination temperature below 500°C, while it showed a sudden increase when more than 600°C. Hydroxy‐carbonate apatite synthesized under a 15% CO2‐containing N2 atmosphere and calcined below 400°C had the greatest selectivity in adsorbing β2‐MG. Thus, a higher selectivity for β2‐MG adsorption was empirically correlated to carbonate ions incorporated in the hydroxyapatite lattice. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 69A: 544–551, 2004
Effect of SACCHACHITIN on keratinocyte proliferation and the expressions of type I collagen and tissue‐transglutaminase during skin wound healing
Authors: Hung Wei‐Sheng , Lai Wen‐Fu T. , Leu Bowen , Su Ching‐Hua , Fang Chia‐Lang , Tsai Yu‐Hui 
Published: April 2004

AbstractSACCHACHITIN is a skin wound‐healing membrane made of residual fruiting body of Ganoderma tsugae. Its effect on proliferating cell nuclear antigen (PCNA) expression in actively proliferating cells, type I collagen expression and tissue remodeling in the healing tissue, and the association of tissue‐transglutaminase (t‐TGase) with wound healing were investigated by immunohistochemical staining. The results demonstrated that PCNA expressed in keratinocytes since day 1 in the SACCHACHITIN group and persisted during entire healing process. In contrast, it was barely detectable on day 3 in the control group. At keratinocyte layer, the SACCHACHITIN group exhibited more type I collagen than did the control group since day 1. At scar tissue, type I collagen was positively stained in the SACCHACHITIN group since day 7 but not in the control group till day 12. Furthermore, t‐TGase was strongly expressed on the inner wall of angiogenic vessels on day 5 of the control group but not on that of the SACCHACHITIN group until day 10. The earlier expressions of PCNA and type I collagen in the keratinocyte layer may lead to accelerated skin wound healing. In addition, the later expression of t‐TGase, an indicator of apoptosis, on the inner wall of angiogenic capillaries in the SACCHACHITIN group may indicate a longer period of blood supply to the wound area, thus facilitating wound healing. These observed phenomena might underline the beneficial effects of SACCHACHITIN membrane on rapid wound healing. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 70B: 122–129, 2004