bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetics of Tethering Quaternary Ammonium Compounds to K+ Channels
Authors: Blaustein Robert O.
Published: September 2002

Polymeric maleimido–quaternary ammonium (QA) compounds have been shown to function as molecular tape measures when covalently tethered to external cysteine residues of a Shaker K+ channel (Blaustein R.O., P.A. Cole, C. Williams, and C. Miller. 2000. Nat. Struct. Biol. 7:309–311). For sufficiently long compounds, the cysteine–maleimide tethering reaction creates a high concentration, at the channel's pore, of a TEA-like moiety that irreversibly blocks current. This paper investigates a striking feature of the maleimide–cysteine tethering kinetics. Strong blockers—those that induce substantial levels (>80%) of irreversible inhibition of current—react with channel cysteines much more rapidly than weak blockers and, when delivered to channels with four cysteine targets, react with multiexponential kinetics. This behavior is shown to arise from the ability of a strong blocker to concentrate its maleimide end near a channel's cysteine target by exploiting the reversible pore-blocking affinity of its QA headgroup.
Knowledge and information management in e‐learning environments; the user agent architecture
Authors: Metaxiotis Kostas , Psarras John , Papastefanatos Stefanos
Published: September 2002

Knowledge management has recently received considerable attention in the computer information systems community and is continuously gaining interest from industry, enterprises and government. As we move towards building knowledge organizations, knowledge management in combination with information management will play a fundamental role towards the success of transforming individual knowledge into organizational knowledge. In this framework, this paper discusses the key concepts of human‐computer interaction in knowledge management, identifies new challenges of knowledge management for Web‐based business and proposes a “user agent architecture” for knowledge management in e‐learning environments. User agents use artificial neural network technology and can be used in various e‐learning or e‐training environments, in order to provide them with means of managing information stored, filtering content and enabling better knowledge adoption on behalf of their users.
A Secondary Structure That Contains the 5′ and 3′ Splice Sites Suppresses Splicing of Duck Hepatitis B Virus Pregenomic RNA
Authors: Loeb Daniel D. , Mack Amanda A. , Tian Ru
Published: September 2002

Pregenomic RNA (pgRNA) plays two major roles in the hepadnavirus life cycle. It is the mRNA for two proteins required for DNA replication, C and P, and it is the template for reverse transcription. pgRNA is a terminally redundant transcript whose synthesis does not involve RNA splicing. For duck hepatitis B virus (DHBV), a spliced RNA is derived from pgRNA by removal of a single intron. The mechanism for the simultaneous cytoplasmic accumulation of unspliced (pgRNA) and spliced RNA was not known. We found that mutations within two regions of the DHBV genome reduced the level of pgRNA while increasing the level of spliced RNA. One region is near the 5′ end of pgRNA (region A), while the second is near the middle of pgRNA (region B). Inspection of the DHBV nucleotide sequence indicated that region A could base pair with region B. The 5′ and 3′ splice sites of the intron of the spliced RNA are within regions A and B, respectively. Substitutions that disrupted the predicted base pairing reduced the accumulation of pgRNA and increased the accumulation of spliced RNA. Restoration of base pairing, albeit mutant in sequence, resulted in restoration of pgRNA accumulation with a decrease in the level of spliced RNA. Our data are consistent with a model in which splicing of the pgRNA is suppressed by a secondary structure between regions A and B that occludes the splicing machinery from modifying pgRNA.
Characterization of the Putative Replisome Organizer of the Lactococcal Bacteriophage r1t
Authors: Zúñiga Manuel , Franke-Fayard Blandine , Venema Gerard , Kok Jan , Nauta Arjen
Published: September 2002

Analysis of the nucleotide sequence of the genome of the lactococcal bacteriophage r1t showed that it may encode at least two proteins involved in DNA replication. On the basis of its similarity with the G38P protein encoded by the
Bacillus subtilis
phage SPP1, the product of
orf11
(Pro11) is thought to be involved in the initiation of phage DNA replication. This protein was overexpressed in
Lactococcus lactis
and partially purified. Gel retardation analysis using various r1t DNA fragments indicates that Pro11 specifically binds to a sequence located within its cognate gene. DNase I footprinting showed that Pro11 protects a stretch of DNA of 47 bp. This region spans four 6-bp short direct repeats, which suggests that the region contains four binding sites for Pro11. 1,10-Phenanthroline-copper footprinting confirmed the protection of the hexamers. An asymmetric protection pattern of each strand was observed, suggesting that Pro11 contacts each DNA strand separately at contiguous hexamers. We propose a model for the binding of Pro11 to its target sites that may account for the torsion strain required for strand opening at the origin of replication.
Mice Deficient in Perforin, CD4+T Cells, or CD28-Mediated Signaling Maintain the Typical Immunodominance Hierarchies of CD8+T-Cell Responses to Influenza Virus
Authors: Chen Weisan , Bennink Jack R. , Morton Phillip A. , Yewdell Jonathan W.
Published: September 2002

CD8 T-cell (TCD8+) responses elicited by viral infection demonstrate the phenomenon of immunodominance: the numbers of TCD8+responding to different viral peptides vary over a wide range in a reproducible manner for individuals with the same major histocompatibility complex class I alleles. To better understand immunodominance, we examined TCD8+responses to multiple defined viral peptides following infection of mice with influenza virus. The immunodominance hierarchy of influenza virus-specific TCD8+was not greatly perturbed by the absence of either perforin or T-helper cells or by interference with B7 (CD80)-mediated signaling. These findings indicate that costimulation by antigen-presenting cells (APCs) or killing of APCs by TCD8+plays only a minor role in establishing the immunodominance hierarchy of antiviral TCD8+in this system. This points to intrinsic features of the TCD8+repertoire as major contributors to immunodominance.
Rev Inhibition Strongly Affects Intracellular Distribution of Human Immunodeficiency Virus Type 1 RNAs
Authors: Cmarko Dusan , Bøe Stig-Ove , Scassellati Catia , Szilvay Anne Marie , Davanger Svend , Fu Xiang-Dong , Haukenes Gunnar , Kalland Karl-Henning , Fakan Stanislav
Published: September 2002

To define the human immunodeficiency virus type 1 (HIV-1) RNA maturation pathways, we analyzed the intracellular distribution of HIV-1 RNA and the viral regulatory proteins Rev and Tat in transfected COS cells and HIV-1-infected lymphoid C8166 cells by means of ultrastructural in situ hybridization using antisense RNA probes and immunoelectron microscopy. The intranuclear viral RNA occurs in ribonucleoprotein fibrils in the perichromatin and interchromatin regions. The simultaneous demonstration of Rev, Tat, Br-labeled RNA, and cellular proteins SC35 and CRM1 in such fibrils reveals the potential of Rev to associate with nascent HIV pre-mRNA and its splicing complex and transport machinery. In a
rev
-minus system, the
env
intron-containing, incompletely spliced viral RNAs are revealed only in the nucleus, indicating that Rev is required to initiate the transport to the cytoplasm. Moreover,
env
intron sequences frequently occur in the periphery of interchromatin granule clusters, while the probe containing the
rev
exon sequence does not associate with this nucleoplasmic domain. When cells were treated with the CRM1 inhibitor leptomycin B in the presence of Rev protein, the
env
intron containing HIV RNAs formed clusters throughout the nucleoplasm and accumulated at the nuclear pores. This suggests that Rev is necessary and probably also sufficient for the accumulation of incompletely spliced HIV RNAs at the nuclear pores while CRM1 is needed for translocation across the nuclear pore complex.
Elevated Chemokine Responses Are Maintained in Lungs after Clearance of Viral Infection
Authors: Weinberg Jason B. , Lutzke Mary L. , Efstathiou Stacey , Kunkel Steven L. , Rochford Rosemary
Published: September 2002

We observed two patterns of chemokine expression in the lungs of mice infected with murine gammaherpesvirus 68: peaks of chemokine expression correlated with or occurred after the peak of viral gene expression. Chemokine expression remained elevated through 29 days postinfection.
Human Herpesvirus 8 Gene Encodes a Functional Thymidylate Synthase
Authors: Gáspár Gábor , De Clercq Erik , Neyts Johan
Published: September 2002

We demonstrate that human herpesvirus 8, obtained from the lymphoma cell line BC-3 as well as from Kaposi's sarcoma lesions, carries a gene that encodes a functional thymidylate synthase (TS). The particular characteristics of this enzyme are studied and compared to the characteristics of TSs encoded by other organisms.
C*-ALGEBRAS OF TRIVIAL K-THEORY AND SEMILATTICES
Authors: LIN HUAXIN
Published: September 2002

We give a class of nuclear C*-algebras which contains [Formula: see text] and is closed under stable isomorphism, ideals, quotients, hereditary subalgebras, tensor products, direct sums, direct limits as well as extensions. We show that this class of C*-algebras is classified by their equivalence classes of projections and there is a one to one correspondence between (unital) C*-algebras in the class and countable distributive semilattices (with largest elements). One of the main results is that essential extensions of a C*-algebras which is a direct limit of finite direct sums of corners of [Formula: see text] by the same type of C*-algebras are still direct limits of finite direct sums of corners of [Formula: see text].
THE BETA FUNCTION OF A KNOT
Authors: BRYLINSKI JEAN-LUC
Published: September 2002

We introduce the beta function of a knot in Euclidean three-space. This is a meromorphic function of a complex variable which we prove admits a Bernstein type functional equation. We determine the first residues.
ON THE RATIONALITY OF ALMOST SIMPLE ALGEBRAIC GROUPS
Authors: THǍŃG NGUYÊÑ QUÔĆ
Published: September 2002

We prove the stable rationality of almost simple adjoint algebraic groups, the connected components of the Dynkin diagram of anisotropic kernel of which contain at most two vertices. The (stable) rationality of many isotropic almost simple groups with small anisotropic kernel and some related results in weak approximation over arbitrary fields are discussed.
INDUCTION OF SEMIGROUPS OF ENDOMORPHISMS OF ${\mathfrak B} ({\mathfrak h})$ FROM COMPLETELY POSITIVE SEMIGROUPS OF (n × n) MATRIX ALGEBRAS
Authors: POWERS ROBERT T.
Published: September 2002

The paper concerns Eo-semigroup of [Formula: see text] induced from unit preserving completely positive semigroups of mapping of an (n × n) matrix algebra into itself. It is shown that Eo-semigroups one obtains are completely spatial and the index of the induced semigroup can be easily computed.
ON THE INDEX AND DILATIONS OF COMPLETELY POSITIVE SEMIGROUPS
Authors: ARVESON WILLIAM
Published: September 2002

It is known that every semigroup of normal completely positive maps P = {Pt:t≥ 0} of ℬ(H), satisfying Pt(1) = 1 for every t ≥ 0, has a minimal dilation to an E0 acting on ℬ(K) for some Hilbert space K⊇H. The minimal dilation of P is unique up to conjugacy. In a previous paper a numerical index was introduced for semigroups of completely positive maps and it was shown that the index of P agrees with the index of its minimal dilation to an E0-semigroup. However, no examples were discussed, and no computations were made.

In this paper we calculate the index of a unital completely positive semigroup whose generator is a bounded operator [Formula: see text] in terms of natural structures associated with the generator. This includes all unital CP semigroups acting on matrix algebras. We also show that the minimal dilation of the semigroup P={ exp tL:t≥ 0} to an E0-semigroup is is cocycle conjugate to a CAR/CCR flow.
DIFFUSION AT CONSTANT SPEED IN A MODEL PHASE SPACE
Authors: RAMAKRISHNA S. ANANTHA , KUMAR N.
Published: September 2002

We reconsider the problem of diffusion of particles at constant speed and present a generalization of the Telegrapher process to higher-dimensional stochastic media (d > 1) where the particle can move along 2d directions. We derive the equations for probability density function using the "formulae of differentiation" of Shapiro and Loginov. The model is an advancement over similiar models of photon migration in multiply scattering media for it results in a true diffusion at constant speed in the limit of large dimensions.
THERMODYNAMIC PROPERTIES OF A BCS SUPERCONDUCTOR NEAR ZERO TEMPERATURE
Authors: KRUNAVAKARN B. , YINGPRATANPORN P. , KASKAMALAS S. , YOKSAN S.
Published: September 2002

We theoretically study the thermodynamic properties of a BCS superconductor near zero temperature. Derivations of the temperature dependence of the order parameter and an exact formula for the free-energy difference between the superconducting and normal states are presented as functions of temperature and material parameters of the superconductor. Under the condition that the cut-off energy is much greater than the temperature, formulas for the critical field and specific heat in the superconducting state are presented. Our expressions for these thermodynamic quantities show new corrections to the BCS's results.
TOWARDS AN AUTOMATIC APPROACH FOR VIEW-DEPENDENT GEOMETRY
Authors: KATE ROHIT JAIVANT , KALRA PREM , BANERJEE SUBHASHIS
Published: September 2002

View specific distortions of a 3D model according to its reference drawings are required for cartoon animations. Rademacher introduced a technique called View-Dependent Geometry wherein a 3D view-dependent model changes shape based on the viewing direction. The main problem in constructing a view-dependent model is of deforming the 3D base model according to its reference drawings. In this paper, we propose an automatic method for solving this problem based on a projective camera model. We present results demonstrating our approach.
Role for granulocyte colony–stimulating factor in the generation of human T regulatory type 1 cells
Authors: Rutella Sergio , Pierelli Luca , Bonanno Giuseppina , Sica Simona , Ameglio Franco , Capoluongo Ettore , Mariotti Andrea , Scambia Giovanni , d'Onofrio Giuseppe , Leone Giuseppe
Published: September 2002

Granulocyte colony–stimulating factor (G-CSF) may affect T-cell homeostasis by multiple mechanisms, inducing polarization of cytokine secretion, inhibition of T-cell proliferation, and enhancement of T-cell apoptosis. We analyzed the production of interleukin-10 (IL-10) and transforming growth factor-β1 (TGF-β1) by T cells from healthy volunteer donors treated with recombinant human G-CSF. Highly purified CD4+ T cells obtained before and after G-CSF administration (pre-G and post-G, respectively) were activated using the allogeneic mixed leukocyte reaction. Post-G CD4+T cells produced high levels of IL-10 but undetectable levels of IL-2 and IL-4, whereas the level of TGF-β1 release was comparable to that of pre-G CD4+ T cells. Notably, post-G CD4+ T cells proliferated poorly in response to alloantigens and to recall antigens and suppressed the proliferation of autologous CD4+ T cells in a cell contact–independent and an antigen-nonspecific manner. TGF-β1 and IL-10 were not dispensable for post-G CD4+ T cells to mediate suppression, as shown by neutralization studies. Compared with pre-G CD4+ T cells, alloantigen-activated post-G CD4+ T cells preferentially expressed markers associated with memory T cells, in conjunction with reduced levels of CD28 and CD62L. Collectively, these data demonstrate that CD4+ T cells exposed to G-CSF in vivo acquire the properties of T regulatory (Tr) cells once triggered in vitro through the T-cell receptor, including a peculiar cytokine production profile (IL-10++TGF-β1+IL-2low/−IL-4low/−), an intrinsic low proliferative capacity, and a contact-independent suppression of antigen-driven proliferation. Tr cells generated ex vivo after exposure to G-CSF might be clinically relevant for transplantation medicine and for the treatment of human immune-mediated diseases.
Cytokine and chemokine profiles in autologous graft-versus-host disease (GVHD): interleukin 10 and interferon γ may be critical mediators for the development of autologous GVHD
Authors: Miura Yuji , Thoburn Christopher J. , Bright Emilie C. , Chen Weiran , Nakao Shinji , Hess Allan D.
Published: September 2002

Administration of the immunosuppressive drug cyclosporine A (CsA) following autologous stem cell transplantation paradoxically elicits a systemic autoimmune syndrome resembling graft-versus-host disease (GVHD). This syndrome, termed autologous GVHD, is associated with autoreactive CD8+ T cells that recognize major histocompatibility complex (MHC) class II determinants in association with a peptide from the invariant chain. To investigate the potential role of cytokines and chemokines in autologous GVHD, interleukin 2 (IL-2), IL-4, IL-10, interferon γ (IFN-γ), and macrophage inflammatory protein-1α (MIP-1α) gene expression in peripheral blood mononuclear cells (PBMCs) was determined in 36 patients treated with CsA following transplantation and correlated with the induction of cytolytic activity against autologous phytohemagglutinin-stimulated lymphocytes (PHA-blasts) and the breast cancer cell line (T47D). The determination of gene expression by real-time polymerase chain reaction (PCR) revealed that IL-10 mRNA levels by PBMCs in patients with autologous GVHD were 29-fold higher than in healthy individuals. IFN-γ (4-fold), IL-2 (3-fold), and MIP-1α (44-fold) mRNA levels were also increased in GVHD-induced patients compared with healthy individuals. The ability of PBMCs to lyse autologous PHA-blasts and T47D tumor cells exhibited an identical temporal relationship with expression of IL-10 and IFN-γ during autologous GVHD. Moreover, the susceptibility to autologous GVHD as assessed in 75 patients was significantly associated with the IL-10−1082 G/G polymorphic alleles, allelic variants in the promoter region that govern IL-10 production. These findings indicate that IL-10 may play an unexpected but critical role in autologous GVHD and could be utilized to enhance a graft-versus-tumor effect after transplantation. Interestingly, polymorphisms in the IL-10 promoter region may also explain differences in the susceptibility of patients to autologous GVHD induction.
S-phase–specific interaction of the Fanconi anemia protein, FANCD2, with BRCA1 and RAD51
Authors: Taniguchi Toshiyasu , Garcia-Higuera Irene , Andreassen Paul R. , Gregory Richard C. , Grompe Markus , D'Andrea Alan D.
Published: September 2002

Fanconi anemia (FA) is a human autosomal recessive cancer susceptibility disorder characterized by cellular sensitivity to mitomycin C and defective cell-cycle progression. Six FA genes (corresponding to subtypes A, C, D2, E, F, and G) have been cloned, and the encoded FA proteins interact in a common pathway. DNA damage activates this pathway, leading to monoubiquitination of the downstream FANCD2 protein and targeting to nuclear foci containing BRCA1. In the current study, we demonstrate that FANCD2 also undergoes monoubiquitination during S phase of the cell cycle. Monoubiquitinated FANCD2 colocalizes with BRCA1 and RAD51 in S-phase–specific nuclear foci. Monoubiquitination of FANCD2 is required for normal cell-cycle progression following cellular exposure to mitomycin C. Our data indicate that the monoubiquitination of FANCD2 is highly regulated, and they suggest that FANCD2/BRCA1 complexes and FANCD2/RAD51 complexes participate in an S-phase–specific cellular process, such as DNA repair by homologous recombination.
Long-term reversal of chronic anemia using a hypoxia-regulated erythropoietin gene therapy
Authors: Binley Katie , Askham Zoe , Iqball Sharifah , Spearman Hayley , Martin Leigh , de Alwis Mahesh , Thrasher Adrian J. , Ali Robin R. , Maxwell Patrick H. , Kingsman Susan , Naylor Stuart
Published: September 2002

Anemia is a common clinical problem, and there is much interest in its role in promoting left ventricular hypertrophy through increasing cardiac workload. Normally, red blood cell production is adjusted through the regulation of erythropoietin (Epo) production by the kidney. One important cause of anemia is relative deficiency of Epo, which occurs in most types of renal disease. Clinically, this can be corrected by supplementation with recombinant Epo. Here we describe an oxygen-regulated gene therapy approach to treating homozygous erythropoietin-SV40 T antigen (Epo-TAgh) mice with relative erythropoietin deficiency. We used vectors in which murine Epo expression was directed by an Oxford Biomedica hypoxia response element (OBHRE) or a constitutive cytomegalovirus (CMV) promoter. Both corrected anemia, but CMV-Epo–treated mice acquired fatal polycythemia. In contrast, OBHRE-Epo corrected the hematocrit level in anemic mice to a normal physiologic level that stabilized without resulting in polycythemia. Importantly, the OBHRE-Epo vector had no significant effect on the hematocrit of control mice. Homozygous Epo-TAgh mice display cardiac hypertrophy, a common adaptive response in patients with chronic anemia. In the OBHRE-Epo–treated Epo-TAgh mice, we observed a significant reversal of cardiac hypertrophy. We conclude that the OBHRE promoter gives rise to physiologically regulated Epo secretion such that the hematocrit level is corrected to healthy in anemic Epo-TAghmice. This establishes that a hypoxia regulatory mechanism similar to the natural mechanism can be achieved, and it makes EPOgene therapy more attractive and safer in clinical settings. We envisage that this control system will allow regulated delivery of therapeutic gene products in other ischemic settings.
Current trends in hematopoietic stem cell transplantation in Europe
Authors: Gratwohl Alois , Baldomero Helen , Horisberger Bruno , Schmid Caroline , Passweg Jakob , Urbano-Ispizua Alvaro
Published: September 2002

Major changes have occurred in the transplantation of hematopoietic stem cells (HSCs) during the last decade. This report reveals the changes, reflects current status, and provides medium-term projections of HSC transplantation (HSCT) development in Europe. Data on 132 963 patients, 44 165 with allogeneic HSC transplant (33%) and 88 798 with an autologous HSC transplant (67%), collected prospectively from 619 centers by the European Group for Blood and Marrow Transplantation (EBMT) in 35 European countries between 1990 (4234 HSCTs) and 2000 (19 136 HSCTs) illustrate utilization of HSCT. HSCT increased in all European countries and for all indications. There were major differences depending on disease indication and donor type. Transplantation rates (numbers of HSCTs per 10 million inhabitants) varied from less than 1 for some rare indications to 37.7 ± 4.1 for acute myeloid leukemia in allogeneic HSCT or 95.5 ± 13.5 for non-Hodgkin lymphoma in autologous HSCT. There were indications with a steady, continuing increase and others with initial increase but subsequent decrease. Projections on medium-term development for each disease based on a weighted sensitivity analysis predict an ongoing increase in allogeneic HSCT except for chronic myeloid leukemia. In autologous HSCT they predict an increase for lymphoproliferative disorders, acute myeloid leukemia, myelodysplastic syndromes, and some solid tumors but a decrease for most solid tumors, acute lymphoid leukemia, and chronic myeloid leukemia. Transplantation rates can be predicted with reasonable sensitivity for most disease indications. Despite marked changes in the rapidly developing field of HSCT, this information on current use, trends, and midterm predictions forms a rational basis for patient counseling and health care planning.
Evidence that α-synuclein functions as a negative regulator of Ca++-dependent α-granule release from human platelets
Authors: Park Sang Myun , Jung Han Young , Kim Hyun Ok , Rhim Hyangshuk , Paik Seung R. , Chung Kwang Chul , Park Jeon Han , Kim Jongsun
Published: September 2002

α-Synuclein has been implicated in the pathogenesis of Parkinson disease (PD) and related neurodegenerative disorders. More recently, it has been suggested to be an important regulatory component of vesicle transport in neuronal cells. α-Synuclein is also highly expressed in platelets and is loosely associated with the membrane of the secretory α-granules. However, the functional significance of these observations is unknown. In this study, the possible function of α-synuclein in vesicle transport, with particular regard to α-granule release from the platelets, was investigated. The results showed that ionomycin- or thrombin-induced α-granule secretion was inhibited by exogenous α-synuclein addition in a dose-dependent manner. However, [3H]5-HT release from the dense granules and hexosaminidase release from the lysosomal granules were not affected. Two point mutants (A30P and A53T) found in some familial types of PD, in addition to β-synuclein and α-synuclein112, effectively inhibited PF4 release from the α-granules. However, the deletion mutants, which completely lacked either the N-terminal region or the C-terminal tail, did not affect α-granule release. Interestingly, exogenously added α-synuclein appeared to enter the platelets but did not change the Ca++ level in the platelets at the resting state and the increase in the Ca++level on stimulation. Electron microscopy also supported that α-synuclein inhibits α-granule release. These results suggest that α-synuclein may function as a specific negative regulator of α-granule release in platelets.
Transgenic Mice Harboring Murine Luteinizing Hormone Receptor Promoter/β-Galactosidase Fusion Genes: Different Structural and Hormonal Requirements of Expression in the Testis, Ovary, and Adrenal Gland
Authors: Hämäläinen Tuula , Kero Jukka , Poutanen Matti , Huhtaniemi Ilpo
Published: September 2002

In vivo regulation of the LH receptor (LHR) promoter was studied using transgenic (TG) mice harboring fusion genes containing three different lengths of the LHR promoter (7.4 kb, 2.1 kb, and 173 bp), fused with coding sequence of the Escherichia coli β-galactosidase (β-GAL) reporter gene. The length of the LHR promoter significantly affected the pattern of β-GAL expression. In the testis the shortest promoter directed expression primarily of the full-length β-GAL mRNA, but mainly truncated messages were transcribed from the longer LHR promoter/β-GAL constructs. The case was reversed in the ovary and adrenal gland. Furthermore, we have recently detected strong LHR expression in the adrenal gland of female mice with chronically elevated serum LH. Therefore, the regulation of the adrenal LHR expression was addressed in the present study using the LHR/β-GAL TG mice. Elevated LH levels were achieved in the LHR/β-GAL mice either by gonadectomy or cross-breeding them with TG mice overexpressing a chimeric protein of bovine LH β-subunit and the C-terminal fragment of human chorionic gonadotropin-β. In both models, β-GAL mRNA was found in the adrenal cortex when the 7.4-kb LHR promoter was applied but not in mice carrying the 173-bp LHR promoter. The 7.4-kb construct was activated also in the ovaries in the double TG LHR(β-GAL)/bovine LH β-subunit/C-terminal fragment of human chorionic gonadotropin-βmice in some theca-interstitial cells surrounding the follicles. Hence, the LHR promoter elements essential for directing β-GAL expression to the adrenal gland and ovary (7.4 kb) are different from those recently shown to be essential for the testicular expression (173 bp). In conclusion, elevated serum LH concentrations were found seminal for the LHR promoter activation in the ovaries and adrenals, and different lengths of the promoter are responsible for reporter gene expression in the testis, ovary, and adrenal gland.
Ovarian Stanniocalcin Is Structurally Unique in Mammals and Its Production and Release Are Regulated through the Luteinizing Hormone Receptor
Authors: Paciga Mark , Watson Andrew J. , DiMattia Gabriel E. , Wagner Graham F.
Published: September 2002

Stanniocalcin (STC) is a recently discovered mammalian hormone that is widely distributed in many tissues. In rodents the STC gene is most highly expressed in ovary, specifically in androgen-producing thecal and interstitial cells. In addition, ovarian levels of expression rise 15-fold over pregnancy. The objective of this study was to develop a primary culture system for ovarian thecal-interstitial cells (TICs) to identify factors governing STC production and release. We used highly purified primary cultures of rat and bovine TICs, the purity of which was routinely assessed with antigenic and enzymatic markers. The functionality of cells was assured by their responsiveness to LH in the form of progesterone release. We found that forskolin significantly increased STC gene expression and secretion by both rat and bovine TICs, an effect that was only replicated by human (h) chorionic gonadotropin (CG). Coincubation of TICs with hCG and phosphodiesterase inhibitors further increased STC secretion, whereas coincubation of TICs with hCG and protein kinase A inhibitors attenuated hCG-stimulated release. Intriguingly, ovarian STC proved to be substantially larger than the 50-kDa homodimer produced in most other tissues. These results indicate that ovarian STC is physically distinct, a feature that could explain its presence in serum during pregnancy and lactation.
Porina Radicicola, A New Lichen from Western North America
Authors: McCarthy P. M. , Tønsberg T.
Published: September 2002

Porina radicicola sp. nov. is described from Washington, U.S.A. and British Columbia, Canada.
Phylogeny of the Parmeliaceae–DNA Data Versus Morphological Data
Authors: Mattsson Jan-Eric , Wedin Mats
Published: September 2002

In order to identify monophyletic groups within the family Parmeliaceae, eleven taxa (Bryoria capillaris, Cetraria islandica, Evernia pruniastri, Hypogymnia physodes, Parmelia saxatilis, Platismatia glauca, Pleurosticta acetabulum, Usneaflorida, Vulpicida juniperina, V. pinastri, and Xanthoparmelia conspersa) were studied using newly produced nuclear rDNA sequence data from the ITS and 5·8S regions. The resulting evolutionary hypothesis was compared with results from previous phylogenetic analyses based on anatomy, morphology, and chemistry. The outcome of this comparison does not support the earlier proposed phylogenies but is not stable enough for identifying monophyletic groups, with one exception. The results indicate a close relationship between Cetraria and Vulpicida, which is contradictory to previous published analyses. The variation in ascus structures in the Parmeliaceae is discussed and it is questioned whether the earlier distinguished ‘ forms ’ of ascus types represent synapomorphies, if they are based on poorly supported analyses, or if they are exaggerations of relatively slight variation in shape. Further interpretations of the results are discussed and areas of future studies based on DNA-data are suggested.
Notes on Polysporina Vězda, with a Description of a New Species from Tasmania
Authors: Kantvilas Gintaras
Published: September 2002

The new species, Polysponna terricola Kantvilas from south-eastern Tasmania, is described and compared to other species in the genus. It is well characterized by a range of morphological, anatomical and ecological characters, especially by the presence of oil paraphyses and oil droplets in the hymenium, features unknown in other members of the genus. Species of Polysporina are best separated by the following characters: size and morphology of the apothecia, size of ascospores, thickness of paraphyses and height of the hymenium. The combinations P. ferniginea (Lettau) M. Steiner and P. pusilla (Anzi) M. Steiner are validated. A key to the taxa studied is provided.
Process and Pattern in Cladonia Subcervicornis
Authors: Hammer Samuel
Published: September 2002

Morphogenesis of podetia in Cladonia subcervicornis is a non-linear, repeating process based upon a pattern of meristem enlargement and division. Variability in mature podetia of C. subcervicornis, which may appear branched or scyphoid, is the result of variation early in ontogeny. The growth pattern of C. subcervicornis represents a continuum of developmental stages. It is impossible to predict the form of the mature thallus of C. subcervicornis because growth in this species is fluid. The morphology of the mature thallus of C. subcervicornis is difficult to circumscribe using conventional Cladonia terminology, because the processes that form the thallus are dynamic and heterogeneous. The meristem shapes that are produced during early ontogeny in C. subcervicornis are relatively simple, and the processes by which they are formed are uncomplicated. Yet podetial form in C.subcercicornis is difficult to interpret.
Natural Levels of Saline Elements in Lichens: Determination of Cellular Fractions and Their Importance as Saline Tracers
Authors: Figueira Rui , Sousa António J. , Brown Dennis H. , Catarino Fernando , Pacheco Adriano M. G.
Published: September 2002

Using a sequential elution procedure, the cellular location of Cl−, Na+, Mg2+, K+ and Ca2+ was determined in the lichen Ramalina canariensis from the southwest coast of Portugal. After a dry deposition period, a logarithmic decrease in the extracellular (surface and wall-bound) concentration of Cl−, Na+ and Mg2+ was observed with increasing distance from the coast. The importance of each cellular fraction as an indication of the airborne salts was identified using factorial analysis methods, as was the relationship between the extracellular and intracellular concentration of the saline elements. The factorial analysis showed that the most important elements for the biomonitoring of airborne salinity were Cl−, Na+ and Mg2+. However, for the cations, only the surface and wall-bound (for Na+) fractions seem to be related to sea-salt deposition on the lichens. The intracellular fractions of these elements are relatively independent of the surface and wall-bound concentrations, or reflect some non-linear processes induced by extreme extracellular concentrations. Although they may represent a significant proportion of the total element concentration, intracellular element concentrations are of little value in monitoring salt deposition, due to physiological control by the organism. The use of total analyses, without any fractional differentiation, can be a biased method for biomonitoring the accumulation of salt spray by lichens, because it includes the intracellular fraction, which may be independent of the deposition taking place. The use of the different cellular fractions provides a more informative indication of the deposition of atmospheric elements, while also giving information on any physiological alterations induced by the specific environmental chemical factors, including membrane damage.
Anisomeridium Musaesporoides, a new Foliicolous Lichen from Tropical America
Authors: Etayo Javier , Lücking Robert
Published: September 2002

A fourth foliicolous species of Anisomeridium is described. Anisomeridium musaesporoides has so far only been found in Guyana and Panama. It is characterized by applanate perithecia with a white marginal zone, large spores with a submedian septum and apical ostiole. A key to all known foliicolous Anisomeridium species is provided.
Caloplaca Cancarixiticola, A New Species from South-East Spain Growing on Ultrapotassic Rocks
Authors: Navarro-Rosinés P. , Egea J.M. , Llimona X.
Published: September 2002

Caloplaca cancarixiticola Nav. -Ros., Egea & Llimona (Teloschistales, Lichenes) is described as new. It is characterized by a lobate thallus weakly attached to the substratum, and narrowly ellipsoid or ellipsoid-fusiform ascospores, (14.5–) 16–22(–25) × (4–)4–5–6um3 with a narrow equatorial wall-thickening, only (1–) 2.5–3.5(–4) um wide. This new species, related to the Caloplaca aurea-group of the subgenus Gasparrinia, was found on cancarixite, an ultrapotassic rock, in a volcanic region of Albacete (SE Spain).
Kantvilasia (Lecanorales, Ectolechiaceae), A New Foliicolous Lichen Genus From Tasmania
Authors: McCarthy P. M. , Elix J. A. , Sérusiaux E.
Published: September 2002

The new genus and species Kantvilasia hians (Lecanorales, Ectolechiaceae) is described from leaves of Atherosperma moschatum at the margin of cool-temperate rainforest in western Tasmania. Notes are provided on characterization, distribution, habitat, associated species, the opening mechanism of campylidia and likely dispersal processes of conidia.
On Rhizocarpon Obscuratum (ACH.) Massal., with notes on some Related Species in the British Isles
Authors: Fryday Alan
Published: September 2002

The specimens upon which Lecidea petraea var. obscurata Ach., the basionym of Rhizocarpon obscuratum (Ach.) Massal., is based are shown to be mostly referable to the species currently known as R. lavatum (Fr.) Hazslin. Rhizocarpon reductum Th. Fr. is resurrected to accommodate specimens with small ascospores previously referred there. The related species R. sublavatum is described from the Scottish Highlands and descriptions provided for R. anaperum (Vain.) Vain, and R. amphibium (Fr.) Th. Fr. These species are compared with R. reductum, R. lavatum and R. petraeum. Rhizocarpon rubescens Th. Fr. is shown to be a distinct species recorded from Europe and N. America.
Caloplaca Erecta, A New Subfruticose Species From New Zealand
Authors: Arup Ulf , Mayrhofer Helmut
Published: September 2002

Caloplaca erecta Arup & H. Mayrhofer is described here as new to science. It belongs to a group of dwarf-fruticose species, but cannot be accommodated within any of the known species of that group. It forms dense cushions of erect lobes on siliceous rocks, and is known only from Mt. Maungatua. This is the second dwarf-fruticose species of Caloplaca in the Australasian area, in addition to C. cribosa.
Amandinea Crassiuscula, a New Corticolous Species from the Iberian Peninsula
Authors: Giralt Mireia , Etayoj Javier , Góomez–Bolea Antonio
Published: September 2002

Amandinea crassiuscula Giralt & Etayo, a new corticolous lichen species is described from the Iberian Peninsula. It is characterized by a thickly crustose to subsquamulose thallus that lacks secondary lichen compounds, lecideine apothecia, Buellia–type ascospores with rugulate ornamentation and filiform spermatia. The new species is compared with other corticolous Amandinea and Buellia species, such as A. punctata and B. chloroleuca. Habit photographs of the new species and illustrations of its thallus, spermatia and ascospores are also provided.
Structural indicators of Richness and rarity of epiphytic lichens on Corylus avellana in two different forest types within a nature reserve in south-western Norway
Authors: Ihlen Per G. , Gjerde Ivar , Sætersdal Magne
Published: September 2002

Epiphytic lichens (and some non-lichenizedfungi) on 34 coppices (204 stems) of Corylus avellana were investigated in a 140 ha study area in south-western Norway. A total of 65 species were recorded on a total bark area of 63 m⊃2. Corylus in broad-leaved deciduous forest supported more species of macrolichens, and fewer species of microlichens, than Corylus in pine forest. The macrolichen flora of the deciduous forest differed from that of the pine forest by having a rich flora of species belonging to the Lobarion alliance. Old Corylus coppices with tall stems (>8 m), large girth (>8cm diameter at breast height) and a noticeable cover of macrolichens (>10% of bark area) supported the highest number of rare species, and overall, species of macrolichens. More than 50% cover of microlichens indicated richness and rarity of microlichens on Corylus. 11 2001 The British Lichen Society
Biatora Britannica sp. Nov. and the Occurrence of Biatora Efflorescens in the British Isles
Authors: Printzen Christian , Lumbsch H. Thorsten , Orange Alan
Published: September 2002

Biatora Britannica sp. nov is described from Wales. The species is the sorediate sister taxon of the Madeiran Biatora hertelii. The close relationship is supported by the presence of the hymenial pigment Hertelii-green, which is hitherto known only from these two species. Molecular data from the nuclear ITS-region of 14 Bratora¯ species renders further support for the close relationship of both species. Sterile, sorediate material from the British Isles earlier referred to B. efflorescens may in fact belong to B. britannica.
A new method to isolate lichen algae by using percoll® gradient centrifugation
Authors: Calatayud Angeles , Guera Alfredo , Fos Simón , Barreno Eva
Published: September 2002

A rapid method to isolate intact functional algae from the lichens Evemia prunastri and Ramalina farinacea has been developed. This method is based on the use of Percoll® gradients after mechanical disruption of lichen thalli. Results obtained show that the algal preparations were virtually free of contamination by fungal hyphae. The purified algal cells were photosynthetically active and without symptoms of photoinhibition, which indicates their functional integrity. This method may be used for the isolation of intact algae from a broad range of lichen species.
Lichenized Species of Omphalina (Tricholomataceae) in the Iberian Peninsula
Authors: Barrasa José María , Rico Víctor J.
Published: September 2002

A taxonomic revision of the lichenized species of the genus Omphalina in the Iberian Peninsula is presented, based upon fungal and lichen herbarium material, as well as on fresh collections. Relevant morphological and ecological features are discussed and a diagnostic key is provided. Four lichenized species, O. ericetorum, O. hudsoniana, O. meridionalis and O. velutina are recognized. A squamulose vegetative thallus (Coriscium-type) is present only in O. hudsoniana, while the other three species form a thallus of hyphal globules (Botrydina-type). Anatomical features of the vegetative thallus cannot be used to distinguish between these last three species. Whilst O. hudsoniana is known only from the montane belt of the Eurosiberian Region and O. meridionalis seems to restricted to the Mediterranean Region, living in more or less humid sites of the Supramediterranean belt, the other two species, O. ericetorum and O. velutina, are widespread.
Early development of Hypogymnia physodes (L.) Nyl. in response to emissions from a copper smelter
Authors: Mikhailova Irina N. , Scheidegger Christoph
Published: September 2002

The early development of Hypogymnia physodes from soredia to the formation of stratified lobes has been studied experimentally in the vicinity of a copper-smelting plant in theMiddle Urals. SEM investigations combined with life table analyses of early developmental stages revealed decreases in soredial survival and developmental rate in polluted localities. Non-stricatified pre-thallus stages without an epicortex were tolerant to toxic impact and were able to survive even in the zone with the highest pollution (lichen desert zone). The sensitivity of developmental stagesancreased after stratified lobes had developed.
Paralethariicola aspiciliae (Ostropales, Odontotremataceae), a new genus and species of lichenicolous fungi
Authors: Calatayud V. , Etayo J. , Diederich P.
Published: September 2002

The generic name Paralethariicola gen. nov. is introduced for a lichenicolous fungus very similar to Lethariicola, but differing by the presence of excipular hairs, asci with a hemiamyloid apical ring and a more flattened apex, curved or slightly helicoid ascospores with ± pointed ends, and thicker paraphyses. The single species, Paralethariicola aspiciliae sp. nov., is lichenicolous on Aspicilia, and is known from continental Spain and Sardinia.
Measurement of Significant Marine Paleotemperature Variation Using Black Abalone Shells from Prehistoric Middens
Authors: Arnold Jeanne E. , Tissot Brian N.
Published: September 2002

The archaeological record from the last millennium in southern California indicates that a period of significant cultural change was associated with a reported marine paleoenvironmental disruption ca. 1150-1250 A.D. A lengthy warm-water anomaly may have in part precipitated more complex sociopolitical and economic responses. We develop independent verification of the perturbation (originally deduced from sediment core data) using archaeological data. Respiratory pore number allometry in the black abalone shell is known to vary clinally in modern populations in response to temperature-induced variation in rate of growth. We use developmental trajectories of abalone from dated, stratified archaeological deposits to reconstruct prehistoric seawater temperatures.
Vegetation Response to Upper Pliocene Glacial/Interglacial Cyclicity in the Central Mediterranean
Authors: Combourieu-Nebout Nathalie
Published: September 2002

New detailed pollen analysis of the lower part of the Upper Pliocene Semaforo section (Crotone, Italy) documents cyclic behavior of vegetation at the beginning of the Northern Hemisphere glaciations. The competition between four vegetation units (subtropical humid forest, deciduous temperate forest, altitudinal coniferous forest, and open xeric assemblage) probably reflects modifications of vegetation belts at this montane site. Several increases in herbaceous open vegetation regularly alternate with subtropical humid forest, which expresses rapid climatic oscillations. The complete temporal succession—deciduous forest (rich inQuercus), followed by subtropical humid forest (Taxodiaceae andCathaya), then altitudinal coniferous forest (Tsuga, Cedrus, Abies,andPicea), and finally herbaceous open vegetation (Graminae, Compositae, andArtemisia)—displays the climatic evolution from warm and humid interglaciation to cold and dry glaciation. It also suggests an independent variation of temperature and humidity, the two main climatic parameters. The vegetation history of southern Calabria recorded in the Semaforo section have been correlated with the ∂18O signal established in the Atlantic Ocean.
Late Quaternary Vegetation and Climate Changes in Central Texas Based on the Isotopic Composition of Organic Carbon
Authors: Nordt Lee C. , Boutton Thomas W. , Hallmark Charles T. , Waters Michael R.
Published: September 2002

Stable carbon isotope analysis of organic carbon in alluvial deposits and soils of three streams in central Texas reveals significant shifts in the ratio of C3 to C4 plant biomass production during the past 15,000 yr. These temporal changes in vegetation appear to be in response to changes in climate. During the late Pleistocene, C4 plants comprised only about 45 to 50% of the vegetative biomass in this area, suggesting that conditions were cooler and wetter than at any time during the past 15,000 yr. The time between 11,000 and 8000 yr B.P. is interpreted as transitional between late Pleistocene conditions and warmer and drier Holocene conditions based on a slight increase in the abundance of C4 plant biomass. During the middle Holocene, between approximately 6000 and 5000 yr B.P., mixed C3/C4 plant communities were replaced almost completely by C4-dominated communities, indicating prairie expansion and warmer and drier climatic conditions. By 4000 yr B.P., the abundance of C4 plant biomass decreased to levels similar to the early Holocene transitional period, suggesting a return to cooler and wetter climatic conditions. No significant shift in the ratio of C3 to C4 productivity has occurred during the last 4000 yr, except for a slight increase in the abundance of C4 plant biomass around 2000 yr B.P. The results of this investigation correlate well with other regional late Quaternary climatic interpretations for central and north Texas, the Southern Plains region, and with other portions of the Great Plains.