bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increased neurogenesis after experimental Streptococcus pneumoniae meningitis
Authors: Gerber Joachim , Böttcher Tobias , Bering Judith , Bunkowski Stephanie , Brück Wolfgang , Kuhnt Ulrich , Nau Roland 
Published: July 2003

AbstractNeuronal damage in the hippocampal formation is a common feature in animal models of bacterial meningitis and human disease. In mouse and rabbit models of Streptococcus pneumoniae meningitis, proliferation of neural progenitor cells quantified by bromodeoxyuridine (BrdU) incorporation was enhanced in the subgranular layer of the dentate gyrus. In mice, the density of BrdU‐labeled cells was maximal on Day 2 after infection. Approximately 60% of the cells labeled by BrdU between Days 7 and 10 after infection that remained present 28 days later had migrated into deeper layers of the dentate gyrus and differentiated into neurons, as evidenced by immunohistochemical staining for TUC‐4, MAP‐2 and beta‐tubulin. This suggests that endogenous repair mechanisms may limit consequences of neuronal destruction after meningitis. © 2003 Wiley‐Liss, Inc.
Unusual topographical pattern of proximal astrogliosis around a cortical devascularizing lesion
Authors: Wang Kai , Walz Wolfgang 
Published: July 2003

AbstractClass II vessels were disrupted on the cortical surface of adult rats within a circular 5‐mm‐diameter area. This consistently resulted in the formation of a conical lesion by day 1, with a cystic cavity forming by day 21. Four markers were used to identify the glial response surrounding the lesion. The antibody used against S100β marked the largest astrocytic pool in the gray matter of the cerebral cortex; only ∼5% of astrocytes were glial fibrillary acidic protein (GFAP)+ in control animals. GFAP served as a marker for distal reactive gliosis and vimentin (VIM) for proximal gliosis. Isolectin B4 was used as an additional marker to distinguish VIM+ microglia from astrocytes inside the lesion area. Three immunohistochemically distinct areas of reactive astrocytes surrounding the lesion were found within 24 hr of injury and lasted through day 6. The first area, in contrast to focal traumatic injuries, consisted of a 196‐μm‐thick boundary layer of S100β+ cells immediately surrounding the lesion that never expressed GFAP or VIM by day 6. This boundary layer turns into a GFAP+ glial limitans encasing the cystic cavity by day 21. A second unusual extended area around the base of the lesion reaching partly into the corpus callosum consisted of S100β+/GFAP+/VIM+ cells. This region appears to be compatible with the local or proximal gliotic response usually found completely surrounding other focal‐type injuries. The proximal response at the base of the lesion developed over the first 3 days in the following sequence: S100β+/GFAP−/VIM− to S100β+/GFAP+/VIM− to S100β+/GFAP+/VIM+. Ninety percent of the astrocytes in this area express VIM. This is very high compared with findings in stab‐wound preparations, where only 10% of astrocytes (surrounding entire lesion) are found to be VIM+. A third region, consistent with a remote or distal reactive gliotic response, demonstrated staining for S100β and had increased GFAP contents throughout the neocortical hemisphere. Cells in this region were never found to be VIM+. Among S100β+ cells close to the boundary region, more than 80% expressed detectable GFAP by 2 days after lesioning. S100β+ cells 1 mm more laterally (distal to lesion) did not express GFAP to the same level until day 6. Thus, we find three immunohistochemically distinct populations of reactive astrocytes surrounding the focal ischemic lesion. In contrast to the case for stab‐wound traumatic injury, the response closest to and surrounding the lesion did not up‐regulate GFAP or VIM by day 6. The proximal response was, instead, more remote and only at the base of the lesion, extending partly into the corpus callosum. © 2003 Wiley‐Liss, Inc.
Glucose uptake in PC12 cells: GLUT3 vesicle trafficking and fusion as revealed with a novel GLUT3‐GFP fusion protein
Authors: Heather West Greenlee M. , Uemura Etsuro , Carpenter Susan L. , Doyle Robert T. , Buss Janice E. 
Published: July 2003

AbstractThe distribution of glucose transporters at the cell surface has a major impact on cellular glucose uptake. In muscle cells and adipocytes, this distribution is under the control of insulin; however, neuronal glucose uptake is not acutely regulated by insulin. Factors that affect the translocation of the neuronal glucose transporter isoform GLUT3 vesicles to and their fusion with the plasma membrane are not well understood. We report that GLUT3 in PC12 cells colocalizes with SNARE complex proteins SNAP‐25 and syntaxin 1, suggesting that fusion of GLUT3‐containing vesicles with the plasma membrane is mediated by these proteins. In addition, it seems that GLUT3 vesicle fusion is regulated, as depolarization increases GLUT3 insertion into the plasma membrane. To study the dynamics of GLUT3 vesicle trafficking, we have created a GLUT3‐GFP fusion protein that is easily expressed in PC12 cells. Trafficking of GLUT3‐GFP seems normal, as 1) its distribution is similar to endogenous GLUT3, 2) GLUT3‐GFP containing vesicles fuse with the plasma membrane evidenced by labeling of the fusion protein with an antibody directed against the exofacial epitope of GLUT3, and 3) glucose uptake is similar to PC12 cells not transfected with GLUT3 fusion protein. These studies are the first to examine GLUT3 trafficking and fusion in PC12 cells, and establish a model system to study regulation of the neuronal glucose transporter. © 2003 Wiley‐Liss, Inc.
Acquisition of an appetitive behavior prevents development of stress‐induced neurochemical modifications in rat nucleus accumbens
Authors: Nanni Giulio , Scheggi Simona , Leggio Benedetta , Grappi Silvia , Masi Flavio , Rauggi Riccardo , De Montis Maria Graziella 
Published: July 2003

AbstractIn rats, exposure to chronic unavoidable stress produces a decrease in dopamine output in the nucleus accumbens shell that is accompanied by a decreased density of the dopamine transporter and an increased activity of the dopamine‐D1 receptor complex. These modifications have been hypothesized to be adaptive to decreased dopamine output in stressed rats. We investigated whether the learning of an appetitive behavior sustained by palatable food, which is associated with increased dopamine output in the nucleus accumbens shell as measured by microdialysis experiments, would affect the modifications induced by chronic stress exposure on dopamine transporter density and dopamine‐D1 receptor complex activity in the nucleus accumbens. Rats exposed to chronic unavoidable stress after acquisition of the appetitive behavior showed a higher dopamine extraneuronal release in the nucleus accumbens shell than that of stressed animals, and similar to that of control rats. Moreover, previous acquisition of the appetitive behavior prevented development of a stress‐induced decrease in dopamine transporter density, measured by [3H]‐WIN 35428 binding, a stress‐induced increase in dopamine‐D1 receptor density, measured by binding of [3H]‐SCH 23390, and SKF 38393‐stimulated adenylyl cyclase activity in the nucleus accumbens. These results support the hypothesis that changes induced in pre‐ and postsynaptic dopaminergic transmission by chronic stress exposure are related to decreased dopamine output. © 2003 Wiley‐Liss, Inc.
α‐tocopherol, an exogenous factor of adult hippocampal neurogenesis regulation
Authors: Cecchini Tiziana , Ciaroni Sandra , Ferri Paola , Ambrogini Patrizia , Cuppini Riccardo , Santi Spartaco , Del Grande Paolo 
Published: July 2003

AbstractIn previous work, we found that adult hippocampal neurogenesis in rat is affected by vitamin E deficiency. Because vitamin E deficiency is a complex condition involving numerous biological systems, it is possible that its effect on postnatal new neuron production could be mediated by unknown changes in different factors that in turn play a role in this process. To clarify if vitamin E plays a direct role in regulating hippocampal neurogenesis, we studied the neurogenesis in adult control rats and in adult rats under supplementation with α‐tocopherol, the most important compound of vitamin E. The α‐tocopherol level in control and supplemented rats was monitored. Qualitative and quantitative analysis of cell proliferation and death was carried out and expression of immature neuron markers PSA‐NCAM, TUC 4, and DCX was investigated in hippocampus dentate gyrus. α‐Tocopherol levels increased significantly in both plasma and brain after supplementation. Cell proliferation was inhibited in α‐tocopherol‐supplemented rats, the number of dying cells was reduced, and the number of cells expressing the immature neuron markers was increased. The results obtained confirm and extend the idea that vitamin E is an exogenous factor playing a direct role in regulation of different steps of adult hippocampal neurogenesis. Some hypotheses about the possible mechanisms underlying the complex action of α‐tocopherol, related to its antioxidant and molecule‐specific non‐antioxidant properties, are proposed and discussed. © 2003 Wiley‐Liss, Inc.
Phase Separations in Water–Salt Solutions of Polyelectrolyte Complexes Formed by RNA and Polycations: Comparison with DNA Complexes
Authors: Wahlund Per‐Olof , Izumrudov Vladimir A. , Gustavsson Per‐Erik , Larsson Per‐Olof , Galaev Igor Yu. 
Published: July 2003

AbstractFormation of insoluble polyelectrolyte complexes (PECs) between RNA and polycations was followed by measuring the residual RNA absorbance in the solution after separation of the precipitate. The polycations studied were poly(N,N′‐dimethyldiallylammonium) chloride (pendant type) and 2,5‐ionene bromide (integral type) with quaternary amino groups in every monomer unit. The data obtained were compared with the results of analogous studies of DNA‐containing PECs. This study is a part of a project aimed at the specific separation of plasmid DNA from RNA, a major problem in the preparative isolation of plasmid DNA. We thus deliberately chose a heterogenous RNA sample as it represents the RNA present in a real cell extract. In contrast to the exhaustive precipitation of DNA observed at certain φ values, a significant part of RNA was nonprecipitated at any φ = [+]/[−], that is, at any ratio of positively charged quaternary amino groups and negatively charged phosphate groups. The addition of sodium chloride increased the nonprecipitated fraction of RNA. DNA, on the other hand, was completely precipitated by both polycations at φ > 0.7. The less effective precipitation of RNA was probably due to the presence of a considerable fraction of short‐chained molecules, incapable of forming a sufficient cooperative system of salt bonds with the polycation. This assumption was supported by a separate experiment, in which the precipitation behavior of RNA fractions of different molecular masses was investigated. The same tendency, while less pronounced, was also ascertained for PECs formed by polycations with DNA fractions of different molecular masses. The possibility of using the revealed differences between DNA and RNA behavior for effective precipitation procedure useful in bioseparation is discussed. The difference in the precipitation behavior of nucleic acids of different molecular masses means there is a possibility for developing an enzymatic assay for DNAase and RNAase activity.The relative residual absorbance of RNA (closed symbols) and DNA (open symbols) remaining in solution after precipitation with 2,5‐ionene bromide as a function of the charge ratio, [+]/[−], determined at different concentrations of sodium chloride (M).magnified imageThe relative residual absorbance of RNA (closed symbols) and DNA (open symbols) remaining in solution after precipitation with 2,5‐ionene bromide as a function of the charge ratio, [+]/[−], determined at different concentrations of sodium chloride (M).
Cationic Graft Copolymers as Carriers for Delivery of Antisense‐Oligonucleotides
Authors: Dautzenberg Herbert , Koňák Čestmír , Reschel Tomáš , Zintchenko Arkadi , Ulbrich Karel 
Published: July 2003

AbstractSelf‐assembling systems based on ionic complexes of DNA fragments (36 base pairs), bcl‐2 antisense oligonucleotides (octadecamer), oligophosphates (25 phosphate groups) or acrylic oligomers (18 groups of phosphonic acid) with poly(L‐lysine) (PLL) ($\overline M _{\rm w}$ = 130 000 and 88 000) grafted with short poly[N‐(2‐hydroxypropyl)methacrylamide] (PHPMA) chains ($\overline M _{\rm n}$ = 4 300 or 8 600) were studied by static and dynamic light scattering methods as systems suitable for gene therapy applications. The graft copolymers (GPLLs) with shorter PHPMA grafts ($\overline M _{\rm n}$ = 4 300) provide polyelectrolyte complexes (PECs) with smaller$\overline M _{\rm w}$andRHthan the corresponding GPLLs with longer grafts ($\overline M _{\rm n}$ = 8 600) and the same content of PLL. The lowest aggregation number of 2 was observed for PECs prepared from the GPLL with short grafts and 40 wt.‐% of PLL. The complexes of oligonucleotides and DNA fragments with GPLLs showed quite similar behavior to that with oligophosphates and acrylic oligomer. The complexes prepared from GPLLs containing 40 wt.‐% of PLL and at excess of oligophosphate were stable for at least 48 h under physiological conditions (0.15MNaCl) and in bovine serum albumin solutions (1 mg · mL−1). Additionally, polyanion exchange reactions of the PECs in contact with poly(styrenesulfonate) and DNA were studied in 0.15MNaCl solutions. The oligophosphates in complexes were at least partially substituted with high‐molecular‐weight polyanions. The structure of the initial PECs dominated the PEC structure after the exchange reaction.The dependence of the molecular weight$\overline M _{\rm w}$(a) and the hydrodynamic radiusRH(b) of complexes of the oligophosphate (OPP) and four graft copolymers (GPLLi,i = 0–3) on the mixing ratioX.magnified imageThe dependence of the molecular weight$\overline M _{\rm w}$(a) and the hydrodynamic radiusRH(b) of complexes of the oligophosphate (OPP) and four graft copolymers (GPLLi,i = 0–3) on the mixing ratioX.
Loss of CD59 expression in breast tumours correlates with poor survival
Authors: Madjd Z , Pinder SE , Paish C , Ellis IO , Carmichael J , Durrant LG 
Published: July 2003

AbstractCD59 (protectin), a phosphatidylinositol‐anchored glycoprotein, is a member of the cell membrane‐bound complement regulatory proteins that inhibits the formation of the terminal membrane attack complex (MAC) of complement. In this study, the expression of CD59 was evaluated in 520 breast carcinomas from patients with a mean follow‐up of 87 months. This expression was correlated with clinicopathological features and patient survival. Marked variation in the intensity of CD59 expression, which correlated with histological grade and Nottingham prognostic index (NPI), was found, with higher expression of CD59 found more often in well and moderately differentiated tumours and those of good prognosis (NPI ≤ 3.4). In contrast, high grade and poor prognosis (NPI > 5.4) carcinomas significantly demonstrated lack of CD59 expression (p < 0.001). Moreover, it was found that the percentage of CD59‐positive cells correlated significantly with patient survival, ie patients with a high percentage of positive cells (>50%) had a better overall survival (p = 0.006). A correlation was also found between the percentage of CD59‐positive cells and tumour type and also the development of distant metastases. No association was found between either the intensity or the percentage of cells expressing CD59 and vascular invasion, lymph node stage, tumour size, patient age or menopausal status. In multivariate analysis, CD59 percentage positivity was of independent prognostic significance with grade and lymph node stage. These findings indicate that loss of CD59 may offer a selective advantage for breast cancers, resulting in more aggressive tumours and conferring a poor prognosis for patients. Copyright © 2003 John Wiley & Sons, Ltd.
Quantitative analysis of colorectal tissue microarrays by immunofluorescence and in situ hybridization
Authors: Jubb AM , Landon TH , Burwick J , Pham TQ , Frantz GD , Cairns B , Quirke P , Peale FV , Hillan KJ 
Published: July 2003

AbstractThe accuracy and reliability of in situ studies may be compromised by qualitative interpretations. Quantitation imposes a greater degree of objectivity, is more reproducible, and facilitates the clarity of definitions. The aim of this study was to validate the utility of laser imaging systems for the in situ quantitative analysis of gene expression in tissue microarrays. Immunofluorescence was employed to quantify the expression of the tumour suppressor p53, a marker of proliferation (Ki67), an endothelial cell marker (CD31), and the mismatch repair proteins human Mut L homologue 1 and human Mut S homologue 2 in an arrayed series of colorectal tissues (n = 110). Quantitative data on this panel of antigens were compared objectively with qualitative scoring of immunohistochemical chromogen deposition. In addition, the expression of vascular endothelial growth factor (VEGF)‐A, placental growth factor, hepatocyte growth factor, and c‐Met mRNA was quantified by phosphor image analysis of in situ hybridization reactions. The quantified data on p53, Ki67, and CD31 expression were significantly associated with the pathologist's score (p ≤ 0.001). While hepatocyte growth factor and placental growth factor were not up‐regulated, c‐Met expression was increased up to 2.5‐fold and the median VEGF‐A expression was elevated 4‐fold (p = 0.003) in this series of colorectal tumours. Laser imaging systems are therefore feasible for high‐throughput, quantitative profiling of tissue microarrays. Copyright © 2003 John Wiley & Sons, Ltd.
Expression of p53, pRB, and p16 in lung tumours: a validation study on tissue microarrays
Authors: Leversha MA , Fielding P , Watson S , Gosney JR , Field JK 
Published: July 2003

AbstractTissue microarrays have been created from 326 lung tumours, including 173 squamous cell carcinomas (SCCs) and 132 adenocarcinomas (ADs). In order to evaluate the usefulness of this microarray series, the expression of p53, p16, and Rb proteins was compared by immunohistochemistry on both the tissue microarrays and the corresponding whole sections for all 326 tumours. The presence of replicate punches improved both the yield and the concordance of data relative to the whole section results, so that the consensus score from the replicates agreed with the whole section result in more than 90% of informative tumours. The large number of tumours in this series also allowed significant differences in protein expression patterns to be detected between SCC and AD, the major subtypes of non‐small cell lung carcinoma (NSCLC). SCC had higher levels of p53 staining (67% vs 52% in AD) and substantially increased p16 loss (SCC 75%, AD 53%) combined with greater retention of pRB expression (SCC 86% vs 67% in AD). The strong inverse correlation between p16 and pRB seen in SCC was essentially absent in AD. This study represents the largest single immunohistochemical survey of protein expression for p53, p16, and RB in NSCLCs. Copyright © 2003 John Wiley & Sons, Ltd.
Raman spectroscopy, a potential tool for the objective identification and classification of neoplasia in Barrett's oesophagus
Authors: Kendall Catherine , Stone Nicholas , Shepherd Neil , Geboes Karel , Warren Bryan , Bennett Robert , Barr Hugh 
Published: July 2003

AbstractHistopathology remains the gold standard technique for the diagnosis of intraepithelial neoplasia (dysplasia) in Barrett's oesophagus, but it is highly subjective and relies on blind biopsy targeting. The aim of this study was to evaluate Raman spectroscopy, a rapid, non‐invasive, molecular, specific analytical technique, for the objective identification and classification of Barrett's neoplasia in vitro. A secondary objective was to demonstrate the need for a rigorous gold standard in the development of new diagnostic techniques. Forty‐four patients with a mean age of 69 years (range 34–89 years) undergoing surveillance for Barrett's oesophagus were included in the study. Three consultant pathologists independently assessed snap‐frozen oesophageal biopsy specimens. Raman spectra were measured on 87 histopathologically homogeneous samples. Spectral classification models were developed using multivariate analysis for the prediction of pathology. Histopathology and Raman classification results were compared. Raman spectral prediction with a consensus pathology classification model gave sensitivities between 73% and 100% and specificities of 90–100%. A high level of agreement (κ = 0.89) was demonstrated between the three‐subset biopsy targeting model and consensus pathology opinion. This compares favourably with the agreement measured between an independent pathologist and the consensus pathology opinion for the same spectra (κ = 0.76). Raman spectroscopy appears to provide a highly sensitive and specific technique for the identification and classification of neoplasia in Barrett's oesophagus. Copyright © 2003 John Wiley & Sons, Ltd.
Expression of nitric oxide synthase isoforms in human liver cirrhosis
Authors: Mohammed Nasser A , Abd El‐Aleem Seham , Appleton Ian , Maklouf Madiha M , Said Mahmoud , McMahon Raymond FT 
Published: July 2003

AbstractSeveral mediators of systemic vasodilatation in liver cirrhosis have been reported. Among these is nitric oxide (NO), which has been proposed as one of the main mediators. In this study, sera and liver biopsies were analysed from 15 patients with clinically and pathologically diagnosed liver cirrhosis. In addition, sera from seven and liver biopsies from three healthy controls were used. Serum levels of nitrite (the end product of NO) were measured using the Griess reaction and the expression of the inducible nitric oxide synthase (iNOS) and constitutive nitric oxide synthase (ecNOS) proteins was investigated using immunohistochemistry. This study shows that serum nitrite levels (94 ± 9.8 µmol/l) in cirrhotic patients were significantly (p < 0.05) increased in comparison with the controls (36.6 ± 11.03 µmol/l). iNOS was completely absent from the control group but was highly expressed in the livers from the cirrhotic group. iNOS was seen mainly in the inflammatory cells infiltrating the portal tracts, blood monocyte‐like cells, hepatocytes, sinusoidal cells, and endothelial cells. However, expression of ecNOS was only seen in the vascular endothelial cells of both the control and the cirrhotic groups, but was much higher in the latter. It is therefore clear that NO is augmented in cirrhotic patients and it is mainly produced by induction of iNOS. Moreover, NO up‐regulation is dependent on the inflammatory stage of liver cirrhosis. ecNOS production could be a normal chronic adaptation mechanism of the endothelium to the chronically increased splanchnic blood flow secondary to portal hypertension. In the near future, the appropriate inhibition of NO activity by using NOS‐active agents may provide a novel strategy for the treatment of patients with liver cirrhosis. Copyright © 2003 John Wiley & Sons, Ltd.