bluuebunny/crossref_metadata_2025 huggingface dataset:
Dehydration‐induced proliferation of identified pituicytes in fully adult rats
Authors: Murugaiyan P. , Salm A. K.
Published: May 2005

The mitotic activity astrocytes in the adult central nervous system (CNS) is of interest due to their roles in gliosis and tumorigenesis, and their potential in aiding recovery of function following injury or disease. The posterior pituitary offers a potentially powerful model to study proliferation in vivo, since its resident astrocytes, called pituicytes, have been reported to divide concurrently with hormone release from the neurosecretory terminals there. Our aim in this study was to confirm and characterize this proliferative response during dehydration and rehydration in fully adult animals, using contemporary techniques. Adult male rats were given 2% saline in substitution for water for 0–9 days. Proliferation of pituicytes was quantified in tissue sections triple‐labeled with the proliferation marker, 5‐bromodeoxyuridine (BrdU), the astrocyte marker glial fibrillary acidic protein (GFAP), and the DNA marker 4,6, diamidino‐2‐phenylindole, HC1 (DAPI). A robust proliferative response began within three days of dehydration and continued at a constant rate thereafter. In animals allowed to rehydrate, this response continued. After 9 days of dehydration, approximately 35% of pituicytes had participated in mitosis. While cell density remained constant across conditions, a reversible increase in posterior pituitary area was seen, suggesting that some cell death also occurs simultaneously. A significant proportion of non‐pituicytes also underwent similar changes. These results indicate that pituicytes in the adult posterior pituitary retain characteristics necessary for reentering the cell cycle in response to local factors present during neurosecretory activity. We hypothesize that this proliferative response is directly related to the morphological changes previously reported for these cells under activating conditions. © 1995 Wiley‐Liss, Inc.
Changes in ion channel expression during in vitro differentiation of trout oligodendrocyte precursor cells
Authors: Glassmeier G. , Jeserich G.
Published: May 2005

Voltage‐gated ionic currents were studied in cultured trout oligodendrocyte precursor cells derived from larval trout brain with the whole‐cell mode of the patch‐clamp technique. These bipolar cells which carry the ganglioside epitope A2B5 on their surface differentiated in vitro into immature multipolar oligodendrocytes expressing the myelin glycoprotein IP2, which signifies the initial step of oligodendroglial development in fish CNS. Depolarization above ‐40 mV activated a fast transient sodium inward current that was eliminated by substituting Na+ for choline and blocked in the presence of 1 μM TTX. The kinetics and the voltage‐dependence of inactivation (half‐maximal inactivation at ‐68 mV) resembled those of sodium currents described in mammalian oligodendrocyte precursor cells and CNS neurons. The expression of Na+ channels was developmentally regulated, since high amplitudes were measured only in A2B5+ cells with a characteristic bipolar morphology of glial progenitors. Depolarizing voltage steps, additionally elicited outward potassium currents that were sensitive to external 4‐AP. In a subpopulation of cells this outward current consisted of a sustained and a transient component. The amplitude of both components were dependent on the prepulse potential. © 1995 Wiley‐Liss, Inc.
O‐2A progenitors of the mouse optic nerve exhibit a developmental pattern of antigen expression different from the rat
Authors: Fanarraga Monica L. , Sommer Ilse , Griffiths Ian R.
Published: May 2005

In a previous study we demonstrated that differentiation and development of mouse oligodendrocytes is similar to that of the rat after the stage at which O4 is acquired. In this present study we compare directly the early differentiation of oligodendrocytes in the mouse and rat post natal optic nerve and show that the two species differ at the O‐2A progenitor and proligodendroblast stages. Mouse progenitors show a variety of morphologies compared to the typical bipolar appearance in the rat. Many murine cells fail to immunolabel with A2B5, GD3, O4, and RmAb, classical markers for rat progenitors, proligodendroblasts, and immature oligodendrocytes. We find that these “unlabeled” cells stain for GAP‐43 and that expression of GAP‐43 overlaps A2B5 and GD3 in the earlier progenitors and 04, RmAb, and 01 in the later proligodendroblasts and immature oligodendrocytes.

Our data suggest that in the development of the mouse O‐2A progenitor cells there is a developmental discontinuity between the earlier markers such as A2B5 and GD3 and the later marker O4, which can be filled by GAP‐43. We therefore consider that GAP‐43 could be used in the mouse, in addition to the classical O‐2A markers, for the study of the early oligodendrocyte lineage as it labels an otherwise undetectable O‐2A population. © 1995 Wiley‐Liss, Inc.
Glial reactivity in the retina of adult rats
Authors: Huxlin Krystel R. , Dreher Zofia , Schulz Mark , Dreher Bogdan
Published: May 2005

The present study aimed to characterize the reaction of mammalian (rat) retinal macroglia (Müller cells and astrocytes) to disturbances of their environment in the form of intraorbital section of the optic nerve, intraocular insertion of a thin glass capillary (without damage to the retina) or a combination of both. Glial reactivity was assessed through the use of a battery of antibodies which recognise four different proteins—glial fibrillary protein (GFAP) and three other proteins designated repectively MA1, 4D6 and 4H11. Retinal astrocytes did not exhibit any changes in normally expressed GFAP or MA1. By contrast, the expression of GFAP and MA1 in Müller cells increased 14 days following section of the optic nerve and/or intravitreal insertions of a glass capillary. Three days postoperatively, the expression of GFAP, but not MA1, had already increased significantly in Müller cells. 4D6 and 4H11 proteins were not expressed in astrocytes. In Müller cells, the levels of these proteins increased significantly following combined optic nerve section and intraocular insertion of a glass capillary. Thus, a mechanical disturbance of the intraocular environment constitutes a more effective stimulus in increasing the expression of some Müllerian proteins than damage to the axons of retinal ganglion cells. Such changes have important implications for various ocular treatments that involve intraocular administration of drugs, as well as for the survival/regeneration potential of retinal ganglion cells undergoing Wallerian degeneration. © 1995 Wiley‐Liss, Inc.
The role of intracellular calcium and protein kinase C in endothelin‐stimulated proliferation of rat type I astrocytes
Authors: Stanimirovic Danica B. , Ball Rita , Mealing Geoff , Morley Paul , Durkin Jon P.
Published: May 2005

The increased expression of immunoreactive endothelin‐1 (ET‐1) in reactive astrocytes and its mitogenic effects on astrocytes and glioma cell lines, have implicated endothelins in the development of reactive gliosis. In this study, an increase in DNA synthesis in rat type I astrocytes was observed after cultures were transiently exposed to ET‐1 for 15 min, suggesting that early signal transduction events are essential and sufficient for the propagation of the ET‐1‐induced mitogenic signal. Prompt increases in inositol triphosphate (IP3) formation and [Ca2+]i were observed upon the addition of ET‐1 to these cells. The ET‐1‐evoked increase in [Ca2+]i consisted of an initial peak which was preserved in Ca2+‐free medium, and a sustained phase which was abolished in Ca2+‐free medium and partly attenuated by nifedipine. ET‐1 also increased the activity of membrane‐associated protein kinase C (PKC) and induced the in vivo phosphorylation of the 85 kD MARCKS protein, an endogenous PKC‐specific substrate. The ET‐1‐evoked increases in DNA synthesis, IP3, [Ca2+]i, membrane PKC, and 85 kD MARCKS protein phosphorylation in rat cortical astrocytes were prevented by either the selective endothelin ETA receptor antagonist, BQ‐123, or the phospholipase C (PLC)‐specific inhibitor, U‐73122. However, the inhibition of PKC activity did not affect ET‐1‐induced DNA synthesis in rat cortical astrocytes. These results suggest that ET‐1‐induced IP3 and/or [CA2+]i responses, but not the activation of PKC, are essential for the growth‐factor like actions of ET‐1 in rat cortical astrocytes. © 1995 Wiley‐Liss, Inc.
Amyloid precursor protein (APP) expression in multiple sclerosis lesions
Authors: Gehrmann Jochen , Banati Richard B. , Cuzner M. Louise , Kreutzberg Georg W. , Newcombe Jia
Published: May 2005

The amyloid precursor protein (APP) is rapidly induced in reactive glial cells in response to several pathological stimuli including inflammation. In the present study, observations previously made in animal models of autoimmune central nervous system inflammation have been extended to the analysis of multiple sclerosis (MS) lesions. A total of thirty fresh‐frozen tissue blocks from six histopathologically normal control and six MS cases have been examined immunocytochemically with monoclonal antibodies directed against either C‐ or N‐terminal epitopes of APP. Histopathological evaluation of disease progression was based on hematoxylin‐eosin and oil red O staining and immunocytochemistry for T cells, macrophages/microglia, astrocytes, and oligodendrocytes. In control cases, APP immunoreactivity was generally low and confined to blood vessel walls, oligodendrocytes in white, and neurons in grey matter. In actively demyelinating plaques, however, levels of APP immunoreactivity were high, localised on T lymphocytes, foamy macrophages, activated microglia, and reactive astrocytes including astrocytic processes. In more chronic lesions, levels of APP immunoreactivity were generally lower than in acute lesions, mainly found on reactive astrocytes, their processes and a few macrophages/microglia depending on the stage of plaque development. In addition, a few 14E‐positive oligodendrocytes and, moreover, numerous axons exhibited APP immunoreactivity, which was particularly pronounced with anti‐C‐terminal antibodies. These results demonstrate that APP is induced on reactive glial cells but also on T lymphocytes during demyelination. The extent of APP expression appears to be correlated to histopathological lesion development and thus suggests that APP detection serves as a sensitive marker for disease progression in MS. © 1995 Wiley‐Liss, Inc.
Developmental pattern of GFAP and vimentin gene expression in rat brain and in radial glial cultures
Authors: Sancho‐Tello María , Vallés Soraya , Montoliu Carmina , Renau‐Piqueras Jaime , Guerri Consuelo
Published: May 2005

In the present study we analyze the events which occur during the early stages of astrogliogenesis by examining the pattern of both GFAP and vimentin gene expression and their corresponding immunoreactive proteins during rat brain development. This study was carried out “in vivo” (whole brain) and “in vitro” (primary culture of radial glia) using immunofluorescence, immunoblotting, and Northern blot analysis. Our results demonstrate that although GFAP immunostaining appeared late in gestation and at day 5 in radial glia cultures, GFAP mRNA expression was first detected, at very low levels, on fetal (F) day 15 and increased to F21. During postnatal development a striking increase in GFAP and its encoding messenger occurs. In contrast, the levels of vimentin and its mRNA expression were very high during the fetal stage (F15 to F21). Thereafter vimentin expression declined during postnatal (P) development until P21 and then remained constant at adult levels. In contrast, an increase in vimentin expression was observed in glial cells throughout the entire culture period. The biological significance of the developmental patterns of GFAP and vimentin expression in astroglial cells during brain development is discussed. © 1995 Wiley‐Liss, Inc.
Evidence for cyclooxygenase activation by nitric oxide in astrocytes
Authors: Molina‐Holgado Francisco , Lledó Alberto , Guaza Carmen
Published: May 2005

We have evaluated the role of nitric oxide (NO) on the cyclooxygenase pathway in mouse glial cells. Exposure of primary cultures of neonatal mouse cortical astrocytes to bacterial lipopolysaccharide (LPS; 1 μg/ml, 18 h) caused an increase in the release of both nitrite (NO−2) and prostaglandin E2 (PGE22), products of NO synthase (NOS) and cyclooxygenase, respectively. Production of both, NO−2 and PGE2 by astrocytes, was inhibited by the exposure of the NOS inhibitor Nw‐nitro‐L‐arginine methyl ester (L‐NAME: 1, 10, and 100 μM) in a dose related manner. Besides, other NOS inhibitors such as Nitro L‐arginine (NNA: 10−3 M) prevented the increase in PGE2 release from LPS‐stimulated astrocytes. Sodium nitroprusside (SNP; 100–200 μM) used as a NO donor caused a dose‐related enhancement in the accumulation of PGE2 induced by LPS and the presence of hemoglobin blocked the SNP effects. The exposure to SNP counteracted the decrease of PGE2 production in LPS‐treated astrocytes in which NO synthesis was blocked by L‐NAME. In addition, SNP also enhanced the synthesis of PGE2 following exogenous arachidonic acid astrocytes exposure. Interestingly, this effect was blocked by indomethacin. Treatment of astrocytes cultures with dexamethasone (0.1, 1 μM) blocked dose‐relatedly the LPS‐induced release of both NO−2 and PGE2. As expected, the presence of indomethacin (1, 10, and 20 μM) prevented in a dose related fashion, PGE2 production by astrocytes following exposure to LPS. These results strongly indicate that in astroglial cells, NO is able to activate the cyclooxygenase pathway. © 1995 Wiley‐Liss, Inc.
Iron‐mediated bioactivation of 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) in glial cultures
Authors: Di Monte Donato A. , Schipper Hyman M. , Hetts Steven , Langston J. William
Published: May 2005

Primary cultures of mouse astrocytes were treated with both the monoamine oxidase (MAO) A inhibitor, clorgyline, and the MA0 B inhibitor, deprenyl, prior to the addition of the neurotoxicant 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP). Production of the 1‐methyl‐4‐phenylpyridinium (MPP+) toxic metabolite was reduced to 11%, but not completely blocked, by MA0 inhibition. This residual MPP+ production appeared to be iron‐dependent since it was decreased (30 to 50%) by iron chelators, i.e., deferoxamine or phenanthroline, and was enhanced (by approximately 40%) in the presence of ADP‐Fe3+. ADP‐Fe3+ also enhanced the oxidation of MPTP to MPP+ which occurs in medium without cells. MPP+ formation, however, was significantly slower in plain culture medium than in astrocyte incubations pretreated with MAO inhibitors, suggesting the involvement of cells in these iron‐mediated reactions. The data indicate that oxidation via MA0 is the primary but not the only pathway of MPTP bioactivation and that transition metals may contribute to the generation of the toxic MPP+ metabolite in biological systems. © 1995 Wiley‐Liss, Inc.
Histopathology, classification, and grading of gliomas
Authors: Kleihues Paul , Soylemezoglu Figen , Schäuble Barbara , Scheithauer Bernd W. , Burger Peter C.
Published: May 2005

Neoplastic transformation occurs in all glial cell types of the human nervous system, producing a wide variety of clinico‐pathological entities and morphological variants. Astrocytomas are most common and span an unusually wide spectrum, ranging from the slowly growing juvenile pilocytic astrocytoma to the highly malignant glioblastoma multiforme. Diffusely infiltrating astrocytomas of the cerebral hemispheres show an inherent tendency for progression towards a more malignant phenotype. This change is morphologically categorized in histologic grading schemes (e.g., WHO Grade II to IV) and is associated with the sequential acquisition of genetic alteration, including mutation in the p53 and homozygous deletion of the p16 tumor suppressor genes. Loss of heterozygosity on chromosomes 10 and 19q as well as amplification of the EGF receptor are largely restricted to malignant gliomas and thus considered late events in astrocytoma progression. Gliomas often show phenotypic expresson of different glial cell lineages (e.g., oligoastrocytoma). Recent studies sugeest that the occurrence of mixed glomas is not indicative of a polyclonal orgin but rather reflects altered gene exprssion leading to a charge in the balance of growth factors influencing glioma defferentiation. © 1995 Wiley‐Liss, Inc.
Platelet‐derived growth factor in human glioma
Authors: Westermark Bengt , Heldin Carl‐Henrik , Nistér Monica
Published: May 2005

Platelet‐derived growth factor (PDGF) is a 30 kDa protein consisting of disulfide‐bonded dimers of A‐ and B‐chains. PDGF receptors are of two types, α‐ and β‐receptors, which are members of the protein‐tyrosine kinase family of receptors. The receptors are activated by ligand‐induced dimerization, whereby the receptors become phosphorylated on tyrosine residues. These form attachment sites for signalling molecules, which inter alia activate the Ras · Raf pathway. PDGF has important functions in development and is required for a proper timing of oligodendrocyte differentiation. The v‐sis oncogene of simian sarcoma virus (SSV) is a retroviral homolog of the B‐chain gene, and induces transformation by an autocrine activation of PDGF receptors at the cell surface. SSV induces malignant glioma in experimental animals, suggesting a role for autocrine PDGF in glioma development. PDGF and PDGF receptors are frequently coexpressed in human glioma cell lines. Specific and nonspecific PDGF antagonists block the growth of some glioma cell lines in vitro and in vivo, suggesting that autocrine PDGF is involved in transformation and tumorigenesis. In situ studies of human gliomas show overexpression of α‐receptors in glioma cells of high‐grade tumors. In a few cases, overexpression is caused by receptor amplification. Since high‐grade glioma cells also express the PDGF A‐chain, an autocrine activation of the α‐receptor may drive the proliferation of glioma cells in vivo. © 1995 Wiley‐Liss, Inc.
Cytokines and tumors of the central nervous system
Authors: Van Meir Erwin G.
Published: May 2005

Cytokines are a group of molecules with an extremely broad range of activities on a variety of target cells. This review summarizes the known cytokine and cytokine receptor expression in primary brain tumors and derived cell lines. These expression patterns are compared with those occurring in other CNS diseases, such as virus or bacterial infections, experimental allergic encephalitis, multiple sclerosis, and trauma. A variety of cytokines are expressed during CNS neoplasia; their potential involvement in tumor growth through a variety of mechanisms, such as autocrine or paracrine growth stimulation, angiogenesis, and immune surveillance evasion, are discussed. Finally, results of preliminary therapeutic approaches with cytokines are critically evaluated. © 1995 Wiley‐Liss, Inc.
Neurofibromatosis type 2 and von Hippel‐Lindau disease: From gene cloning to function
Authors: Kley Nikolai , Whaley Jean , Seizinger Bernd R.
Published: May 2005

Most of the genes for hereditary tumor syndromes cloned thus far have subsequently been shown to be mutated not only in the germlines and tumors from patients with the relatively rare inherited disease, but also in the much more common sporadic tumor counterparts in the general population. Thus, the isolation and functional characterization of genes associated with hereditary tumor syndromes have emerged as a major strategy to gain insights into some of the most fundamental mechanisms of tumorigenesis.

The search for the genes causing two hereditary tumor syndromes of the nervous system, neurofibromatosis type 2 (NF2) and von Hippel‐Lindau disease (VHL), has recently culminated in the cloning of both disease genes. This represents another successful application of the so‐called positional cloning approach, i.e., the isolation of a hereditary disease gene with unknown function, based on the determination of its chromosomal location in the human genome.

The gene for NF2, a syndrome typically associated with vestibular schwannomas and meningiomas, is homologous with a family of genes whose members appear to play an important role in bridging the cell membrane with the intracellular cytoskeleton, including moesin, ezrin, radixin, and protein 4.1. Recent mutation analyses have revealed that the NF2 tumor suppressor gene is frequently mutated not only in vestibular schwannomas and meningiomas from NF2 patients, but also in their sporadic counterparts, which represent approximately one‐third of all human brain tumors. Furthermore, malignant human tumors seemingly unrelated to the NF2 syndrome, such as neural crest‐derived malignant melanomas, as well as malignant mesotheliomas (a pleural mesoderm‐derived tumor), have also been found to be frequently mutated or deleted in the NF2 locus, suggesting a broader role for the NF2 gene in the initiation and progression of human neoplasms.

VHL is a rare tumor syndrome characterized by certain types of nervous system tumors (cerebellar and spinal hemangioblastomas as well as retinal angiomas), in conjunction with bilateral renal cell carcinomas and pheochromocytomas. Similar to NF2, recent genetic mutation studies have revealed that the VHL tumor suppressor gene is not only mutated in the hereditary tumors from VHL patients, but also in their sporadic counterparts. Importantly, the VHL gene represents the most frequently mutated cancer‐related gene thus far identified in sporadic renal cell carcinoma. In contrast to most other hereditary cancer syndromes, however, VHL mutations are surprisingly specific for tumors typically associated with the VHL syndrome, and have not been detected in any other tumor type unrelated to VHL.

The cloning and initial genetic characterization of the NF2 and VHL genes have now provided a rational basis for subsequent functional studies on the elucidation of the normal and tumor‐associated cellular signaling pathways of these tumor suppressor genes. © 1995 Wiley‐Liss, Inc.
Molecular pathways in the formation of gliomas
Authors: von Deimling Andreas , Louis David N. , Wiestler Otmar D.
Published: May 2005

The past few years have seen remarkable progress in understanding the molecular genetic basis of glioma formation. Affected oncogenes and tumor suppressor genes have been identified and putative tumor suppressor loci have been mapped. These studies have illustrated distinct molecular pathways for different glial neoplasms. We summarize the findings of an ongoing study initiated to characterize human gliomas on a molecular basis. The data are compiled from 150 astrocytic, oligodendroglial, and mixed gliomas that were assessed for genomic alterations characteristic of these neoplasms, i.e., loss of portions of chromosomes 1p, 9p, 10, 17p, 17q, and 19q, mutations of the p53 tumor suppressor gene, and amplification of the EGF receptor (EGFR) gene. Our findings support the hypothesis that distinct genetic pathways result in the formation of astrocytic and oligodendroglial neoplasms of different malignancy grades, and that glioblastoma multiforme may be subdivided into genetically distinct subsets. Such findings may not only lead to a better understanding of neoplastic transformation in glial cells, but may also have a major impact on clinical neuro‐oncology. © 1995 Wiley‐Liss, Inc.
Angiogenesis in malignant gliomas
Authors: Plate Karl H. , Risau Werner
Published: May 2005

One event that accompanies glioma progression is the upregulation of angiogenesis. Low‐grade gliomas are moderately vascularized tumors whereas high‐grade gliomas show prominent microvascular proliferations and areas of high vascular density. To analyze the molecular mechanisms underlying glioma angiogenesis, we studied the expression of vascular endothelial growth factor (VEGF) and its tyrosine kinase receptors VEGFR‐1 and VEGFR‐2 during normal brain development and glioma‐induced angiogenesis. Our results suggest a paracrine control of angiogenesis and endothelial cell proliferation that is tightly regulated and transient in the embryonic brain, switched off in the normal adult brain, and turned on in tumor cells (VEGF) and the host vasculature (VEGFR‐1 and −2) during tumor progression. It is unknown how VEGF and VEGF receptors are upregulated during glioma angiogenesis, but there is recent evidence that VEGF as well as endogenous inhibitors of angiogenesis could be under control of the tumor suppressor genes p53 and VHL. © 1995 Wiley‐Liss, Inc.
Transgenic and gene disruption techniques in the study of neurocarcinogenesis
Authors: Aguzzi Adriano , Brandner Sebastian , Isenmann Stefan , Steinbach Joachim P. , Sure Ulrich
Published: May 2005

Transgenic technologies have come of age, and the field of carcinogenesis has profited extensively from the availability of these methods. Both the inappropriate expression of dominant oncogenes in specific tissues and the ability to “knock out” tumor suppressor genes in mammalian organisms have enabled substantial advancements of our understanding of development and progression of the neoplastic phenotype. In the first part of this article, we review the most popular techniques for modification of the mammalian genome in vivo, i.e. microinjection of fertilized eggs, retrovirus‐mediated gene transfer, and targeted gene deletion through homologous recombination. Subsequently, we attempt a critical evaluation of the available models of neurocarcinogenesis, and discuss their impact and future potential for the study of cancer in the nervous system. © 1995 Wiley‐Liss, Inc.
Daily Cannabis Smoking as a Risk Factor for Progression of Fibrosis in Chronic Hepatitis C *
Authors: Hézode Christophe , Roudot-Thoraval Françoise , Nguyen Son , Grenard Pascale , Julien Boris , Zafrani Elie-Serge , Pawlostky Jean-Michel , Dhumeaux Daniel , Lotersztajn Sophie , Mallat Ariane
Published: May 2005

Cannabinoids present in

Cannabis sativa

(marijuana) exert biological effects via cannabinoid receptors CB1 and CB2. We recently demonstrated that CB1 and CB2 receptors regulate progression of experimental liver fibrosis. We therefore investigated the impact of cannabis smoking on fibrosis progression rate in patients with chronic hepatitis C (CHC). Two hundred seventy consecutive untreated patients with CHC of known duration undergoing liver biopsy were studied. Demographic, epidemiological, metabolic, and virological data were recorded, and detailed histories of cannabis, alcohol, and tobacco use over the span of hepatitis C virus infection were obtained. Fibrosis stage, steatosis, and activity grades were scored according to Metavir system. Patients were categorized as noncannabis users (52.2%), occasional users (14.8%), or daily users (33.0%), and the relationship between cannabis use and fibrosis progression rate (FPR) or fibrosis stage was assessed. On multivariate analysis, six factors were independently related to a FPR greater than 0.074 (median value of the cohort): daily cannabis use (OR = 3.4 [1.5-7.4]), Metavir activity grade A2 or higher (OR = 5.4 [2.9-10.3]), age at contamination of more than 40 years (OR = 10.5 [3.0-37.1]), genotype 3 (OR = 3.4 [1.5-7.7]), excessive alcohol intake (OR = 2.2 [1.1-4.5]), and steatosis (OR = 2.0 [1.0-4.1]). Daily cannabis use was also an independent predictor of a rapid FPR (>0.15) (OR = 3.6 [1.5-7.5]). Finally, severe fibrosis (≥F3) was also predicted by daily cannabis use (OR = 2.5 [1.1-5.6];

P

= .034), independently of Metavir activity grade, excessive alcohol intake, age at liver biopsy, steatosis, and tobacco smoking.
In conclusion
, daily cannabis smoking is significantly associated with fibrosis progression during CHC. Patients with ongoing CHC should be advised to refrain from regular cannabis use. (Hepatology 2005;.)
Osteoblast interactions with calcium phosphate ceramics modified by coating with type I collagen
Authors: Brodie J. C. , Goldie E. , Connel G. , Merry J. , Grant M. H.
Published: May 2005

Complications associated with the use of autogenous bone in the repair or replacement of tissue lost through injury or disease have driven the search for alternative sources of graft material. Bioceramics containing hydroxyapatite (HA), tricalcium phosphate (TCP), or composites that combine the best properties of both of these materials are among the principal candidates. In this study, we have investigated the in vitro proliferation, morphology, and viability of an immortalized rat osteoblast cell line cultured on HA, TCP, and composites of the two in the ratios 75:25 (H75), 50:50 (H50), and 25:75 (H25) for 28 days. The biocompatibility of each material was examined in the presence and absence of a collagen coating. With the exception of H50, cell proliferation, quantified by carboxyfluorescein fluorescence, was enhanced by collagen coating of all materials for the first 14 days, although at later time points cell numbers were unaffected. It is notable that the collagen coating was least stable on H50, the only material not to show enhancement of cell growth on coating. Confocal laser scanning microscopy confirmed that cell growth was more extensive on coated materials over the first 7–14 days in culture, and the development of cell extensions and bridges across the pores in the materials was observed. Results indicate that collagen coating of calcium phosphate ceramics may also increase their compatibility and osseointegration in vivo. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Bioactive hydroxyapatite coatings on polymer composites for orthopedic implants
Authors: Auclair‐Daigle C. , Bureau M. N. , Legoux J.‐G. , Yahia L'H.
Published: May 2005

Hydroxyapatite [HA, Ca10(PO4)6(OH)2] coatings on polymer composite substrates were investigated for their bioactivity and their physicochemical and mechanical characteristics. HA holds key characteristics for use in orthopedic applications, such as for coating of the femoral stem in a hip replacement device. The plasma‐spray technique was used to project HA onto a carbon fiber/polyamide 12 composite substrate. The resulting HA coatings exhibited mechanical adhesion as high as 23 MPa, depending on the surface treatment of the composite substrate. The purpose of this investigation was to evaluate the bioactivity of an HA‐coated composite substrate. HA‐ coated samples have been immerged in simulated body fluid (SBF) and maintained within a shaker bath for periods of 1, 7, 14, 21, and 28 days at 37°C. Scanning electron microscopy, energy dispersive X‐ray spectroscopy, and X‐ray diffraction techniques were performed on the samples before and after immersion into SBF. SBF was analyzed using inductively coupled plasma atomic emission spectrometry for element concentration and evaluation of the solution's purity. SBF conditioning led to the deposition of crystalline HA onto the surface of the coatings. The calcium‐to‐phosphorous ratios of initial HA coating and of newly deposited HA were respectively 1.72 and 1.65, close to the HA theoretical calcium/phosphorous value of 1.67. Results demonstrated that bioactive HA coatings were produced by plasma spraying, because SBF conditioning induced newly formed HA with high crystallinity. Mechanical adhesion of the HA coatings was not significantly affected upon SBF conditioning. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Autologous peripheral blood stem cell collections in children weighing less than 10 Kg with solid tumors: Experience of a single center
Authors: Cho Hyun‐Jung , Jung Hae‐Kyung , Sung Ki‐Woong , Ku Hong‐Hae , Lee Sue‐Hyun , Kim Dae‐Won
Published: May 2005

There have only been a few reports and limited performance of peripheral blood stem cell (PBSC) collection in very small children weighing less than 10 kg. In this study, we intended to evaluate the safety and yield of PBSC collection, with the efficacy of PBSC transplantation (PBSCT) in the smallest children with solid tumors. From January 1998 to February 2004, 173 children underwent PBSC collection in Samsung Medical Center, Korea. Of these, 15 (8.7%) children weighed less than 10 kg and their clinical diagnoses were neuroblastoma (10 cases), rhabdoid tumor (2 cases), rhabdomyosarcoma (2 cases), and Wilms tumor (1 case). PBSCs were collected following chemotherapy plus G‐CSF mobilization. The median age and weight at the time of apheresis were 15 months and 9 kg, respectively. The median number of PBSC collection procedures per case was 4 (range, 2–7). The median cell yield per apheresis product was 0.95 (range, 0.01–33.32) × 106/kg CD34+ cells and 1.96 (range, 0.12–23.39) × 108/kg mononuclear cells. No complications associated with citrate toxicity and other adverse effect were observed during the procedures. After high‐dose chemotherapy, 14 patients were reinfused with PBSCs alone and all showed successful hematopoietic recovery. We concluded that PBSC collection would be a safe and practical procedure, even when done in the smallest children, provided that adequate intravascular fluid volume and circulating red cell mass were maintained. Also, the use of PBSCs to support high‐dose chemotherapy was well tolerated and might enhance hematological recovery in the smallest children showing the excellent efficacy of PBSCT. J. Clin. Apheresis © 2005 Wiley‐Liss, Inc.
A case of non‐lethal pulmonary air embolism after leukapheresis catheter removal
Authors: Grífols Joan‐Ramon , Ferrà Christelle , Sancho Juan‐Manuel , Pujol Misericordia , Ribera Josep‐Maria
Published: May 2005

Mononuclear cell leukapheresis requires good‐quality venous access. Catheter placement and removal of the catheter may be associated with life‐threatening local or systemic complications. Thus, prompt recognition of these complications and appropriate therapy can be life‐saving. We report the case of a young man who presented with an air embolism following removal of a jugular venous catheter after peripheral blood stem cell collection. We have reviewed the signs and symptoms presented by the patient and the methodology used to remove the catheter. Catheter removal requires careful attention in order to avoid potentially serious complications. J. Clin. Apheresis © 2005 Wiley‐Liss, Inc.
Electrospray ionization mass and tandem mass spectra of a series of N‐pyrazolylmethyl and N‐triazolylmethyl N‐phenylpiperazines: new dopaminergic ligands with potential antipsychotic properties
Authors: Santos Leonardo S. , Padilha Monica Costa , de Aquino Neto Francisco Radler , Santos Pereira Alberto dos , Menegatti Ricardo , Manssour Fraga Carlos Alberto , Barreiro Eliezer J. , Eberlin Marcos N.
Published: May 2005

Recently, two analogous series of N‐pyrazolylmethyl and N‐triazolylmethyl N‐phenylpiperazines have been prepared and found to be potential antipsychotic drugs acting as new selective ligands of the dopamine D2 receptor. Herein we report a systematic study of their high‐resolution electrospray ionization mass and tandem mass spectra in which the main dissociation routes of their protonated molecules are determined and rationalized. The ESI‐MS/MS data is very characteristic for both series allowing straightforward isomeric differentiation. A single and dominant fragment ion for the pyrazole series and four major fragment ions for the triazole series are useful for selective reaction MS monitoring of these potential drugs in biological fluids. Copyright © 2005 John Wiley & Sons, Ltd.
Analysis of parasitic quantum effects in classical CMOS circuits
Authors: Felgenhauer F. , Begoin M. , Mathis W.
Published: May 2005

In the mesoscopic regime, the MOS device performance is affected by gate‐induced quantization effects leading to a loss of transconductance and threshold voltage shift and gate leakage tunnelling currents degrading the overall device performance. We discuss the expected impact of quantum effects in highly down scaled CMOS circuits. Based on 1‐d numerical simulations for transport in mesoscopic systems, we set up Spice circuit models. The Spice models rebuild the influence of quantum effects; and the functionality of classical circuit concepts can be ‘tested’ in their robustness against these effects. A few circuit examples will be given. Copyright © 2005 John Wiley & Sons, Ltd.
Lymph node metastasis in an animal model: Effect of piecemeal laser surgical resection
Authors: Sapundzhiev Nikolay R. , Dünne Anja A. , Ramaswamy Annette , Sitter Helmut , Davis R. Kim , Werner Jochen A.
Published: May 2005

Background and Objectives

Endoscopic laser surgical resection of advanced squamous cell carcinoma (SCC) often requires division of the tumor into several pieces. It is unknown if this approach influences the incidence of regional and distant metastases.

Study Design/Materials and Methods

In 143 rabbits VX2 SCC was induced. Eight days later the tumor was resected by two different methods. In the first group en bloc cold steel resection was performed. In the second group piecemeal laser resection was performed. On the 51th day the animals were sacrificed and examined for lymph node and distant metastases.

Results

After piecemeal laser resection 47.7% of the animals had lymph node metastases compared to 24.6% after en bloc resection (P = 0.01). The incidence of distant metastases did not differ for the two groups.

Conclusions

In our model narrow margin piecemeal laser resection was associated with a higher incidence of metastases compared to wide en bloc surgical resection. The exact mechanism responsible for this increase is unclear. © 2005 Wiley‐Liss, Inc.
Microgel‐Based Engineered Nanostructures and Their Applicability with Template‐Directed Layer‐by‐Layer Polyelectrolyte Assembly in Protein Encapsulation
Authors: Shenoy Dinesh B. , Sukhorukov Gleb B.
Published: May 2005

Summary: A novel strategy for the fabrication of microcapsules is elaborated by employing biomacromolecules and a dissolvable template. Calcium carbonate (CaCO3) microparticles were used as sacrificial templates for the two‐step deposition of polyelectrolyte coatings by surface controlled precipitation (SCP) followed by the layer‐by‐layer (LbL) adsorption technique to form capsule shells. When sodium alginate was used for inner shell assembly, template decomposition with an acid resulted in simultaneous formation of microgel‐like structures due to calcium ion‐induced gelation. An extraction of the calcium after further LbL treatment resulted in microcapsules filled with the biopolymer. The hollow as well as the polymer‐filled polyelectrolyte capsules were characterized using confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), and scanning force microscopy (SFM). The results demonstrated multiple functionalities of the CaCO3 core – as supporting template, porous core for increased polymer accommodation/immobilization, and as a source of shell‐hardening material. The LbL treatment of the core‐inner shell assembly resulted in further surface stabilization of the capsule wall and supplementation of a nanostructured diffusion barrier for encapsulated material. The polymer forming the inner shell governs the chemistry of the capsule interior and could be engineered to obtain a matrix for protein/drug encapsulation or immobilization. The outer shell could be used to precisely tune the properties of the capsule wall and exterior.

Confocal laser scanning microscopy (CLSM) image of microcapsules (insert is after treating with rhodamine 6G to stain the capsule wall).

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Confocal laser scanning microscopy (CLSM) image of microcapsules (insert is after treating with rhodamine 6G to stain the capsule wall).
in vitro Evaluation of Biodegradable Poly(butylene succinate) as a Novel Biomaterial
Authors: Li Haiyan , Chang Jiang , Cao Amin , Wang Junying
Published: May 2005

Summary: Poly(butylene succinate) (PBSU) can be easily synthesized by condensation polymerization of the starting materials of succinic acid and butan‐1,4‐diol. It has good degradability and possesses excellent processability. Due to these advantages, PBSU was first evaluated in the present study for its potential application as a novel biomaterial. The in vitro biocompatibility of the PBSU was evaluated by monitoring proliferation and differentiation of osteoblasts cultured on the PBSU film substrates for different periods. The results showed that the PBSU was biocompatible as the osteoblasts could proliferate and differentiate on the PBSU plates. In addition, the hydrolytic degradation behavior of the PBSU films in the phosphate‐buffered saline (PBS) was also investigated and the results suggested that the PBSU degraded in the PBS solution with the same behavior as that of the degradable poly(α‐hydroxyesters). In addition to the biocompatibility and hydrolytic degradation, some physical properties, including hydrophilicity, and mechanical and thermal properties of the PBSU substrates, were also determined and the results revealed that the PBSU was hydrophilic and ductile with excellent processability. The biocompatibility of the PBSU, together with the advantages of hydrolytic degradability, hydrophilicity, and excellent processability, indicated that PBSU has the potential to be used as a biomaterial for tissue repair.

Alkaline phosphate activity of osteoblasts cultured on PBSU and TCPS substrates for different time periods.

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Alkaline phosphate activity of osteoblasts cultured on PBSU and TCPS substrates for different time periods.
Biomolecular Hybrid of a Conducting Polymer with DNA: Morphology, Structure, and Doping Behavior
Authors: Dawn Arnab , Nandi Arun K.
Published: May 2005

Summary: A poly(o‐methoxyaniline) (POMA)/DNA [weight fraction of DNA (WDNA) = 0.45] hybrid was prepared by mixing their solutions in sterilized double distilled water. The solution turned green upon aging for a longer time, and the doping of POMA by DNA was complete after about 15 d of aging. The doping was confirmed from the UV‐vis spectra where the 599 nm peak of POMA(EB) disappeared and a new peak for a π to localized polaron band‐transition appeared. With increasing aging time the new peak gradually shifted from 674 nm at 3 h to 820 nm at 15 d of mixing and thereafter it remained constant. The absence of a free carrier tail in the UV‐vis spectra indicated a coiled structure of POMA in the complex. Circular dichroism spectra of the hybrid solution indicated that the DNA conformation (double helical structure) remained unchanged in the hybrid. The SEM micrograph of the freeze–dried hybrid showed a needle‐like morphology of the DNA dispersed in a polymer matrix and it was completely different from the fibrillar network morphology of pure DNA in the solid state. The TEM micrograph indicated a homogeneous dispersion of DNA fibrils in the POMA matrix. The melting temperature of the POMA–DNA hybrid showed an increase compared to that of pure DNA by 5 °C, probably caused by an electrostatic interaction between the DNA anion and the POMA radical cation generated in the doping process. WAXS investigations revealed that the DNA crystal structure remained unchanged in the hybrid whereas the POMA crystal structure might be lost. An FT‐IR study suggested that interaction occurred between the phosphoric acid group of DNA and a nitrogen atom of POMA through proton transfer from the OH group of the former. A schematic model of the POMA–DNA complex randomly anchoring POMA chains with the DNA molecule was proposed. The dc conductivity of the POMA–DNA complex was found to be ca. 10−7 S · cm−1. Hence, this work describes a procedure for making a DNA‐conducting polymer hybrid without changing the conformation and structure of DNA.

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pH Effects on the Complexation, Miscibility and Radiation‐Induced Crosslinking in Poly(acrylic acid)‐Poly(vinyl alcohol) Blends
Authors: Nurkeeva Zauresh S. , Mun Grigoriy A. , Dubolazov Artem V. , Khutoryanskiy Vitaliy V.
Published: May 2005

Summary: The effect of pH on the complexation of poly(acrylic acid) with poly(vinyl alcohol) in aqueous solution, the miscibility of these polymers in the solid state and the possibility for crosslinking the blends using gamma radiation has been studied. It is demonstrated that the complexation ability of poly(vinyl alcohol) with respect to poly(acrylic acid) is relatively low in comparison with some other synthetic non‐ionic polymers. The precipitation of interpolymer complexes was observed below the critical pH of complexation (pHcrit1), which characterizes the transition between a compact hydrophobic polycomplex and an extended hydrophilic interpolymer associate. Films prepared by casting from aqueous solutions at different pH values exhibited a transition from miscibility to immiscibility at a certain critical pH, pHcrit2, above which hydrogen bonding is prevented. It is shown here that gamma radiation crosslinking of solid blends is efficient and only results in the formation of hydrogel films for blends prepared between pHcrit1 and pHcrit2. The yield of the gel fraction and the swelling properties of the films depended on the absorbed radiation dose and the polymer ratio.

SEM image of an equimolar PAA‐PVA blend cast from a pH 4.6 solution.

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SEM image of an equimolar PAA‐PVA blend cast from a pH 4.6 solution.
Novel Alginate‐Poly(L‐histidine) Microcapsules as Drug Carriers: In Vitro Protein Release and Short Term Stability
Authors: Wang Shi‐Bin , Xu Fei‐Hai , He Hong‐Shan , Weng Lian‐Jin
Published: May 2005

Summary: Spherical, smooth‐surfaced and mechanically stable alginate‐poly(L‐histidine) (PLHis) microcapsules with narrow particle size distributions were prepared by incubating calcium alginate beads in aqueous solutions of PLHis. The in vitro release characteristics, drug loading and encapsulation efficiency of the microcapsules were investigated using bovine erythrocytes hemoglobin (Hb) as a model drug. The results showed that the concentration of Ca2+ ions had a considerable effect on the drug loading, encapsulation efficiency and in vitro release behavior of the microcapsules. When the concentration of CaCl2 in the PLHis solution was increased from 0 to 3.0% (w/v), the drug loading and encapsulation efficiency decreased significantly from 38.0 to 4.3% and from 92.9 to 8.0%, respectively, while the total cumulative release of Hb from microcapsules in phosphate buffered saline solution (PBS, pH 6.8) decreased from 96.2 to 72.8% in 24 h. No significant protein release was observed during 70 h of incubation in hydrochloric acid solution (pH 1.2). However, under neutral conditions (PBS, pH 6.8), the Hb was completely and stably released within 24–70 h. An explosion test showed that the stability of alginate‐PLHis microcapsules depended strongly on the concentration of PLHis and the calcium ions in solution.

Microscopy photo of Hb‐loaded alginate‐PLHis microcapsules.

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Microscopy photo of Hb‐loaded alginate‐PLHis microcapsules.
Bovine mater‐like NALP9 is an oocyte marker gene
Authors: Dalbiès‐Tran Rozenn , Papillier Pascal , Pennetier Sophie , Uzbekova Svetlana , Monget Philippe
Published: May 2005

We have cloned and sequenced the bovine NALP9 cDNA, which contains a 2991 bp long open reading frame with 76% homology to its human counterpart. The putative 996 amino acids protein presents the domain organization typical of the Nacht, Leucine rich repeat and Pyrin domain containing (NALP) family that includes the maternal effect factor MATER. By reverse transcription coupled to polymerase chain reaction, we have analyzed expression of NALP9 in a panel of somatic and gonadic tissues and during in vitro preimplantation development. The transcript was detected exclusively in testis and ovary, and at a remarkably high level in the oocyte from antral follicles. NALP9 mRNA remained present after in vitro maturation and fertilization, and was detected in embryos, but transcription was not reactivated at the maternal to embryo transition. Thus NALP9 is characterized as a novel oocyte marker gene in cattle. Mol. Reprod. Dev. © 2005 Wiley‐Liss, Inc.