bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Role of CD8+T Cells and Major Histocompatibility Complex Class I Genes in the Generation of Protective CD4+Th1 Responses during Retrovirus Infection in Mice
Authors: Peterson Karin E. , Stromnes Ingunn , Messer Ron , Hasenkrug Kim , Chesebro Bruce
Published: July 2002

CD4+Th1 responses to virus infections are often necessary for the development and maintenance of virus-specific CD8+T-cell responses. However, in the present study with Friend murine retrovirus (FV), the reverse was also found to be true. In the absence of a responderH-2ballele at major histocompatibility complex (MHC) class II loci, a singleH-2DbMHC class I allele was sufficient for the development of a CD4+Th1 response to FV. This effect ofH-2Dbon CD4+T-cell responses was dependent on CD8+T cells, as demonstrated by depletion studies. A direct effect of CD8+T-cell help in the development of CD4+Th1 responses to FV was also shown in vaccine studies. Vaccination of nonresponderH-2a/amice induced FV-specific responses ofH-2Dd-restricted CD8+cytotoxic T lymphocytes (CTL). Adoptive transfer of vaccine-primed CD8+T cells to naiveH-2a/amice prior to infection resulted in the generation of FV-specific CD4+Th1 responses. This novel helper effect of CD8+T cells could be an important mechanism in the development of CD4+Th1 responses following vaccinations that induce CD8+CTL responses. The ability of MHC class I genes to facilitate CD4+Th1 development could also be considerable evolutionary advantage by allowing a wider variety of MHC genotypes to generate protective immune responses against intracellular pathogens.
Proteolytic Processing of a Serotype 8 Human Astrovirus ORF2 Polyprotein
Authors: Méndez Ernesto , Fernández-Luna Teresa , López Susana , Méndez-Toss Martha , Arias Carlos F.
Published: July 2002

Astroviruses require the proteolytic cleavage of the capsid protein to infect the host cell. Here we describe the processing pathway of the primary translation product of the structural polyprotein (ORF2) encoded by a human astrovirus serotype 8 (strain Yuc8). The primary translation product of ORF2 is of approximately 90 kDa, which is subsequently cleaved to yield a 70-kDa protein (VP70) which is assembled into the viral particles. Limited trypsin treatment of purified particles containing VP70 results in the generation of polypeptides VP41 and VP28, which are then further processed to proteins of 38.5, 35, and 34 kDa and 27, 26, and 25 kDa, respectively. VP34, VP27 and VP25 are the predominant proteins in fully cleaved virions, which correlate with the highest level of infectivity. Processing of the VP41 protein to yield VP38.5 to VP34 polypeptides occurred at its carboxy terminus, as suggested by immunoblot analysis using hyperimmune sera to different regions of the ORF2, while processing of VP28 to generate VP27 and VP25 occurred at its carboxy and amino terminus, respectively, as determined by immunoblot, as well as by N-terminal sequencing of those products. Based on these data, the processing pathway for the 90-kDa primary product of astrovirus Yuc8 ORF2 is presented.
RelA-Associated Inhibitor Blocks Transcription of Human Immunodeficiency Virus Type 1 by Inhibiting NF-κB and Sp1 Actions
Authors: Takada Norio , Sanda Takaomi , Okamoto Hiroshi , Yang Jian-Ping , Asamitsu Kaori , Sarol Lilen , Kimura Genjiro , Uranishi Hiroaki , Tetsuka Toshifumi , Okamoto Takashi
Published: July 2002

RelA-associated inhibitor (RAI) is an inhibitor of nuclear factor κB (NF-κB) newly identified by yeast two-hybrid screen as an interacting protein of the p65 (RelA) subunit. In this study, we attempted to examine the effect of RAI on transcription and replication of human immunodeficiency virus type 1 (HIV-1). We found that RAI inhibited gene expression from the HIV-1 long terminal repeat (LTR) even at the basal level. Upon in vitro DNA-binding reactions, RAI could directly block the DNA-binding of p65 subunit of NF-κB but not that of the p50 subunit or AP1. We found that RAI could also inhibit the DNA-binding of Sp1 and thus inhibit the basal HIV-1 promoter activity. We further examined the effects of RAI on Sp1 and found that RAI colocalizes with Sp1 in the nucleus and interacts with Sp1 in vitro and in vivo. Moreover, we found that RAI efficiently blocked the HIV-1 replication when cotransfected with a full-length HIV-1 clone. These findings indicate that RAI acts as an efficient inhibitor of HIV-1 gene expression in which both NF-κB and Sp1 play major roles.
Bacteriophage PM2 Has a Protein Capsid Surrounding a Spherical Proteinaceous Lipid Core
Authors: Kivelä Hanna M. , Kalkkinen Nisse , Bamford Dennis H.
Published: July 2002

The marine double-stranded DNA (dsDNA) bacteriophage PM2, studied since 1968, is the type organism of the family
Corticoviridae
, infecting two gram-negative
Pseudoalteromonas
species. The virion contains a membrane underneath an icosahedral protein capsid composed of two structural proteins. The purified major capsid protein, P2, appears as a trimer, and the receptor binding protein, P1, appears as a monomer. The C-terminal part of P1 is distal and is responsible for receptor binding activity. The rest of the structural proteins are associated with the internal phospholipid membrane enclosing the viral genome. This internal particle is designated the lipid core. The overall structural organization of phage PM2 resembles that of dsDNA bacteriophage PRD1, the type organism of the family
Tectiviridae
.
Characterization of a Polytropic Murine Leukemia Virus Proviral Sequence Associated with the Virus Resistance GeneRmcfof DBA/2 Mice
Authors: Jung Yong Tae , Lyu Myung Soo , Buckler-White Alicia , Kozak Christine A.
Published: July 2002

The DBA/2 mouseRmcfgene is responsible for in vivo and in vitro resistance to infection by the polytropic mink cell focus-forming (MCF) virus subgroup of murine leukemia viruses (MLVs). Previous studies suggested thatRmcfresistance is mediated by expression of an interfering MCF MLV envelope (Env) gene. To characterize thisenvgene, we examined resistance in crosses betweenRmcfrDBA/2 mice andMus castaneus, a species that lacks endogenous MCFenvsequences. In backcross progeny, inheritance ofRmcfresistance correlated with inheritance of a specific endogenous MCF virusenv-containing 4.6-kbEcoRI fragment. This fragment was present in the DBA/2N substrain withRmcf-mediated resistance but not in virus-susceptible DBA/2J substrain mice. This fragment contains a provirus with a 5′ long terminal repeat and the 5′ half ofenv; thegagandpolgenes have been partially deleted. The Env sequence is identical to that of a highly immunogenic viral glycoprotein expressed in the DBA/2 cell line L5178Y and closely resembles theenvgenes of modified polytropic proviruses. The coding sequence for the full-lengthRmcfEnv surface subunit was amplified from DNAs from virus-resistant backcross mice and was cloned into an expression vector. NIH 3T3 and BALB 3T3 cells stably transfected with this construct showed significant resistance to infection by MCF MLV but not by amphotropic MLV. This study identifies anRmcf-linked MCF provirus and indicates that, like the ecotropic virus resistance geneFv4,Rmcfmay mediate resistance through an interference mechanism.
Binding of Human Cytomegalovirus US2 to Major Histocompatibility Complex Class I and II Proteins Is Not Sufficient for Their Degradation
Authors: Chevalier Mathieu S. , Daniels Gwynn M. , Johnson David C.
Published: July 2002

Human cytomegalovirus (HCMV) glycoprotein US2 causes degradation of major histocompatibility complex (MHC) class I heavy-chain (HC), class II DR-α and DM-α proteins, and HFE, a nonclassical MHC protein. In US2-expressing cells, MHC proteins present in the endoplasmic reticulum (ER) are degraded by cytosolic proteasomes. It appears that US2 binding triggers a normal cellular pathway by which misfolded or aberrant proteins are translocated from the ER to cytoplasmic proteasomes. To better understand how US2 binds MHC proteins and causes their degradation, we constructed a panel of US2 mutants. Mutants truncated from the N terminus as far as residue 40 or from the C terminus to amino acid 140 could bind to class I and class II proteins. Nevertheless, mutants lacking just the cytosolic tail (residues 187 to 199) were unable to cause degradation of both class I and II proteins. Chimeric proteins were constructed in which US2 sequences were replaced with homologous sequences from US3, an HCMV glycoprotein that can also bind to class I and II proteins. One of these US2/US3 chimeras bound to class II but not to class I, and a second bound class I HC better than wild-type US2. Therefore, US2 residues involved in the binding to MHC class I differ subtly from those involved in binding to class II proteins. Moreover, our results demonstrate that the binding of US2 to class I and II proteins is not sufficient to cause degradation of MHC proteins. The cytosolic tail of US2 and certain US2 lumenal sequences, which are not involved in binding to MHC proteins, are required for degradation. Our results are consistent with the hypothesis that US2 couples MHC proteins to components of the ER degradation pathway, enormously increasing the rate of degradation of MHC proteins.
Favorable and Unfavorable HLA Class I Alleles and Haplotypes in Zambians Predominantly Infected with Clade C Human Immunodeficiency Virus Type 1
Authors: Tang Jianming , Tang Shenghui , Lobashevsky Elena , Myracle Angela D. , Fideli Ulgen , Aldrovandi Grace , Allen Susan , Musonda Rosemary , Kaslow Richard A. ,   the Zambia-UAB HIV Research Project
Published: July 2002

The setpoint of viral RNA concentration (viral load [VL]) during chronic human immunodeficiency virus type 1 (HIV-1) infection reflects a virus-host equilibration closely related to CD8+cytotoxic T-lymphocyte (CTL) responses, which rely heavily on antigen presentation by the human major histocompatibility complex (MHC) (i.e., HLA) class I molecules. Differences in HIV-1 VL among 259 mostly clade C virus-infected individuals (137 females and 122 males) in the Zambia-UAB HIV Research Project (ZUHRP) were associated with several HLA class I alleles and haplotypes. In particular, general linear model analyses revealed lower log10VL among those with HLA allele B*57 (P= 0.002 [without correction]) previously implicated in favorable response and in those with HLA B*39 and A*30-Cw*03 (P= 0.002 to 0.016); the same analyses also demonstrated higher log10VL among individuals with A*02-Cw*16, A*23-B*14, and A*23-Cw*07 (P= 0.010 to 0.033). These HLA effects remained strong (P= 0.0002 to 0.075) after adjustment for age, gender, and duration of infection and persisted across three orders of VL categories (P= 0.001 to 0.084). In contrast, neither B*35 (n= 15) nor B*53 (n= 53) showed a clear disadvantage such as that reported elsewhere for these closely related alleles. Other HLA associations with unusually high (A*68, B*41, B*45, and Cw*16) or low (B*13, Cw*12, and Cw*18) VL were either unstable or reflected their tight linkage respecting disequilibria with other class I variants. The three consistently favorable HLA class I variants retained in multivariable models and in alternative analyses were present in 30.9% of subjects with the lowest (<10,000 copies per ml) and 3.1% of those with the highest (>100,000) VL. Clear differential distribution of HLA profiles according to level of viremia suggests important host genetic contribution to the pattern of immune control and escape during HIV-1 infection.
Characterization of a Novel Simian Immunodeficiency Virus with a
vpu
Gene from Greater Spot-Nosed Monkeys (
Cercopithecus nictitans
) Provides New Insights into Simian/Human Immunodeficiency Virus Phylogeny
Authors: Courgnaud Valérie , Salemi Marco , Pourrut Xavier , Mpoudi-Ngole Eitel , Abela Bernadette , Auzel Philippe , Bibollet-Ruche Frédéric , Hahn Beatrice , Vandamme Anne-Mieke , Delaporte Eric , Peeters Martine
Published: July 2002

In the present study, we describe a new simian immunodeficiency virus (SIV), designated SIVgsn, naturally infecting greater spot-nosed monkeys (
Cercopithecus nictitans
) in Cameroon. Together with SIVsyk, SIVgsn represents the second virus isolated from a monkey belonging to the
Cercopithecus mitis
group of the
Cercopithecus
genus. Full-length genome sequence analysis of two SIVgsn strains, SIVgsn-99CM71 and SIVgsn-99CM166, revealed that despite the close phylogenetic relationship of their hosts, SIVgsn was highly divergent from SIVsyk. First of all, they differ in their genomic organization. SIVgsn codes for a
vpu
homologue, so far a unique feature of the members of the SIVcpz/human immunodeficiency virus type 1 (HIV-1) lineage, and detailed phylogenetic analyses of various regions of the viral genome indicated that SIVgsn might be a mosaic of sequences with different evolutionary histories. SIVgsn was related to SIVsyk in Gag and part of Pol and related to SIVcpz in Env, and the middle part of the genome did not cluster significantly with any of the known SIV lineages. When comparing the two SIVgsn Env sequences with that of SIVcpz, a remarkable conservation was seen in the V3 loop, indicating a possible common origin for the envelopes of these two viruses. The habitats of the two subspecies of chimpanzees infected by SIVcpz overlap the geographic ranges of greater spot-nosed monkeys and other monkey species, allowing cross-species transmission and recombination between coinfecting viruses. The complex genomic structure of SIVgsn, the presence of a
vpu
gene, and its relatedness to SIVcpz in the envelope suggest a link between SIVgsn and SIVcpz and provide new insights about the origin of SIVcpz in chimpanzees.
Critical Role for Protein Tyrosine Phosphatase SHP-1 in Controlling Infection of Central Nervous System Glia and Demyelination by Theiler's Murine Encephalomyelitis Virus
Authors: Massa Paul T. , Ropka Stacie L. , Saha Sucharita , Fecenko Karen L. , Beuler Kathryn L.
Published: July 2002

We previously characterized the expression and function of the protein tyrosine phosphatase SHP-1 in the glia of the central nervous system (CNS). In the present study, we describe the role of SHP-1 in virus infection of glia and virus-induced demyelination in the CNS. For in vivo studies, SHP-1-deficient mice and their normal littermates received an intracerebral inoculation of an attenuated strain of Theiler's murine encephalomyelitis virus (TMEV). At various times after infection, virus replication, TMEV antigen expression, and demyelination were monitored. It was found that the CNS of SHP-1-deficient mice uniquely displayed demyelination and contained substantially higher levels of virus than did that of normal littermate mice. Many infected astrocytes and oligodendrocytes were detected in both brains and spinal cords of SHP-1-deficient but not normal littermate mice, showing that the virus replicated and spread at a much higher rate in the glia of SHP-1-deficient animals. To ascertain whether the lack of SHP-1 in the glia was primarily responsible for these differences, glial samples from these mice were cultured in vitro and infected with TMEV. As in vivo, infected astrocytes and oligodendrocytes of SHP-1-deficient mice were much more numerous and produced more virus than did those of normal littermate mice. These findings indicate that SHP-1 is a critical factor in controlling virus replication in the CNS glia and virus-induced demyelination.
Kaposi's Sarcoma-Associated Herpesvirus-Induced Upregulation of the c-kitProto-Oncogene, as Identified by Gene Expression Profiling, Is Essential for the Transformation of Endothelial Cells
Authors: Moses Ashlee V. , Jarvis Michael A. , Raggo Camilo , Bell Yolanda C. , Ruhl Rebecca , Luukkonen B. G. Mattias , Griffith Diana J. , Wait Cecily L. , Druker Brian J. , Heinrich Michael C. , Nelson Jay A. , Früh Klaus
Published: July 2002

Kaposi's sarcoma (KS), the most frequent malignancy afflicting AIDS patients, is characterized by spindle cell formation and vascularization. Infection with KS-associated herpesvirus (KSHV) is consistently observed in all forms of KS. Spindle cell formation can be replicated in vitro by infection of dermal microvascular endothelial cells (DMVEC) with KSHV. To study the molecular mechanism of this transformation, we compared RNA expression profiles of KSHV-infected and mock-infected DMVEC. Induction of several proto-oncogenes was observed, particularly the receptor tyrosine kinase c-kit. Consistent with increased c-Kit expression, KHSV-infected DMVEC displayed enhanced proliferation in response to the c-Kit ligand, stem cell factor (SCF). Inhibition of c-Kit activity with either a pharmacological inhibitor of c-Kit (STI 571) or a dominant-negative c-Kit protein reversed SCF-dependent proliferation. Importantly, inhibition of c-Kit signal transduction reversed the KSHV-induced morphological transformation of DMVEC. Furthermore, overexpression studies showed that c-Kit was sufficient to induce spindle cell formation. Together, these data demonstrate an essential role for c-Kit in KS tumorigenesis and reveal a target for pharmacological intervention.
Simian Virus 40 Large T Antigen and Two Independent T-Antigen Segments Sensitize Cells to Apoptosis following Genotoxic Damage
Authors: Cole Sara L. , Tevethia M. J.
Published: July 2002

The simian virus 40 (SV40) large tumor (T) antigen is sufficient to transform cells in cultures and induce tumors in experimental animals. Transformation of primary cells in cultures requires both overcoming growth arrest by stimulating the cell cycle and blocking cell death activities presumably activated by oncogene-mediated hyperproliferation signals. The study presented here examined the ability of specific regions and activities of T antigen to modulate apoptosis in cells treated with the genotoxic agent 5-fluorouracil (5-FU). The results showed that the expression of full-length T antigen rendered rat embryo fibroblasts (REF) sensitive to 5-FU-induced apoptosis. Thus, neither the p53-binding region nor the Bcl-2 homology region of T antigen was sufficient to prevent cell death induced by the DNA-damaging agent. T-antigen-mediated sensitization occurred independently of retinoblastoma protein or p53 and p300 binding. An N-terminal segment containing the first 127 T-antigen amino acids (T1-127) was sufficient to sensitize cells. A C-terminal segment consisting of T-antigen amino acids 251 to 708 (T251-708) also sensitized cells to 5-FU-induced apoptosis. This sensitization did not occur when T251-708 was targeted to the nucleus by inclusion of the SV40 nuclear localization signal. The introduction of mutations into the T-antigen J domain resulted in mutation-specific and variable inhibition of apoptosis. This result suggested that either the structural or the functional integrity of the J domain is required to sensitize cells to apoptosis. Treatment of REF or REF expressing full-length T antigen, an N-terminal segment, or T251-708 resulted in increased expression of the p53-responsive MDM2 gene; apoptosis occurred through a p53-dependent pathway, as p53-null cells expressing these T antigens were resistant to 5-FU-induced apoptosis. Possible mechanisms involved in sensitizing cells to a p53-dependent apoptosis pathway in spite of the ability of T antigen to bind and inactivate the transcriptional transactivating activity of p53 are discussed.
Characterization of the Nuclear Localization Signal of the Borna Disease Virus Polymerase
Authors: Walker Michelle Portlance , Lipkin W. Ian
Published: July 2002

Borna disease virus (BDV) is a nonsegmented negative-strand RNA virus that replicates and transcribes its genome in the nucleus of infected cells. BDV proteins involved in replication and transcription must pass through the nuclear envelope to associate with the genomic viral RNA. The RNA-dependent RNA polymerase (L) of BDV is postulated to be the catalytic enzyme of replication and transcription. We demonstrated previously that BDV L localizes to the nucleus of BDV-infected cells and L-transfected cells. Nuclear localization of the protein presupposes the presence of a nuclear localization signal (NLS) within its primary amino acid sequence or cotransport to the nucleus with another karyophilic protein. Because L localized to the nucleus in the absence of other viral proteins, we investigated the possibility that L contains an NLS. The minimal sequence required for nuclear localization of L was identified by analyzing the subcellular distribution of deletion mutants of L fused to a flag epitope tag or β
-
galactosidase. Although the majority of the L fusion proteins localized to the cytoplasm of transfected BSR-T7 cells, a strong NLS (844RVVKLRIAP852) with basic and proline residues was identified. Mutation of this sequence resulted in cytoplasmic distribution of L, confirming that this sequence was necessary and sufficient to drive the nuclear localization of L.
Hydrophobically Modified Amphiphilic Block Copolymer Micelles in Non-Aqueous Polar Solvents. Fluorometric, Light Scattering and Computer-Based Monte Carlo Study
Authors: Matějíček Pavel , Uhlík Filip , Limpouchová Zuzana , Procházka Karel , Tuzar Zdeněk , Webber Stephen E.
Published: July 2002

The micellization behavior of a hydrophobically modified polystyrene-block-poly(methacrylic acid) diblock copolymer, PS-N-PMA-A, tagged with naphthalene between blocks and with anthracene at the end of the PMA block, was studied in 1,4-dioxane-methanol mixtures by light scattering and fluorescence techniques. The behavior of a single-tagged sample, PS-N-PMA, and low-molar-mass analogues was studied for comparison. Methanol-rich mixtures with 1,4-dioxane are strong selective precipitants for PS. Multimolecular micelles with compact PS cores and PMA shells may be prepared indirectly by dialysis from 1,4-dioxane-rich mixtures, or by a slow titration of copolymer solutions in 1,4-dioxane-rich solvents with methanol under vigorous stirring. In tagged micelles, the naphthalene tag is trapped in nonpolar and fairly viscous core/shell interfacial region. In hydrophobically modified PS-N-PMA-A micelles, the hydrophobic anthracene at the ends of PMA blocks tends to avoid the bulk polar solvent and buries in the shell. The distribution of anthracene tags in the shell is a result of the enthalpy-to-entropy interplay. The measurements of direct nonradiative excitation energy transfer were performed to estimate the distribution of anthracene-tagged PMA ends in the shell. The experimental fluorometric data show that anthracene tags penetrate into the inner shell in methanol-rich solvents. Monte Carlo simulations were performed on model systems to get reference data for analysis of time-resolved fluorescence decay curves. A comparison of experimental and simulated decays indicates that hydrophobic traps return significantly deep into the shell (although not as deep as in aqueous media). The combined light scattering, fluorometric and computer simulation study shows that the conformational behavior of shell-forming PMA blocks in non-aqueous media is less affected by the presence of nonpolar traps than that in aqueous media.
Regio- and Stereoselectivity in Preparation of Benzene Bridged Bis- and Tris-Tröger's Bases
Authors: Valík Martin , Dolensky Bohumil , Petříčková Hana , Král Vladimír
Published: July 2002

Synthetic strategy for novel multiple Tröger's base derivatives is presented. Compounds were prepared in three steps: o-nitrobenzoylation of benzene-1,2- and -1,3-diamines 3 followed by reduction of nitro and amide groups to amino functions and treatment of the obtained tetraamine compounds 6 with formaldehyde lead to simultaneous formation of bis-Tröger's base (bisTB) derivatives 7a, 7b. Only products of 1,2,3,4-substituted regioisomers with anti conformation were separated from reaction mixtures. The same synthetic procedure was used for preparation of tris-Tröger's base (trisTB) derivative 12b starting from benzene-1,3,5-triamine (8).
Pulmonary epithelial response in the rat lung to instilled Montserrat respirable dusts and their major mineral components
Authors: Housley D G , Bérubé K A , Jones T P , Anderson S , Pooley F D , Richards R J
Published: July 2002

Background:The Soufriere Hills, a stratovolcano on Montserrat, started erupting in July 1995, producing volcanic ash, both from dome collapse pyroclastic flows and phreatic explosions. The eruptions/ash resuspension result in high concentrations of suspended particulate matter in the atmosphere, which includes cristobalite, a mineral implicated in respiratory disorders.

Aims:To conduct toxicological studies on characterised samples of ash, together with major components of the dust mixture (anorthite, cristobalite), and a bioreactive mineral control (DQ12 quartz).

Methods:Rats were challenged with a single mass (1 mg) dose of particles via intratracheal instillation and groups sacrificed at one, three, and nine weeks. Acute bioreactivity of the particles was assessed by increases in lung permeability and inflammation, changes in epithelial cell markers, and increase in the size of bronchothoracic lymph nodes.

Results:Data indicated that respirable ash derived from pyroclastic flows (20.1% cristobalite) or phreatic explosion (8.6% cristobalite) had minimal bioreactivity in the lung. Anorthite showed low bioreactivity, in contrast to pure cristobalite, which showed progressive increases in lung damage.

Conclusion:Results suggests that either the percentage mass of cristobalite particles present in Montserrat ash was not sufficient as a catalyst in the lung environment, or its surface reactivity was masked by the non-reactive volcanic glass components during the process of ash formation.
Proposed use of adrenaline (epinephrine) in anaphylaxis and related conditions: a study of senior house officers starting accident and emergency posts
Authors: Gompels L L , Bethune C , Johnston S L , Gompels M M
Published: July 2002

Senior house officers (SHOs) (n=78) at the start of their accident and emergency (A&E) post were given an anonymous five case history questionnaire, containing one case of true anaphylaxis, and asked to complete the medication they would prescribe. In the case of anaphylaxis, 100% would administer adrenaline (epinephrine) but 55% would do so by the incorrect route. In the remaining cases, 10%–56% would be prepared to administer adrenaline inappropriately. Only 5% were able to indicate the correct route and dose of adrenaline according to Resuscitation Council guidelines (UK). This has implications for training as the survey took place before the start of the A&E posting. Anaphylaxis is over-diagnosed and poorly treated despite Resuscitation Council guidelines.
Mammary tuberculosis: report on 52 cases
Authors: Khanna R , Prasanna G V , Gupta P , Kumar M , Khanna S , Khanna A K
Published: July 2002

Fifty two cases of tuberculosis of the breast encountered over a 15 year period and accounting for 3% of all breast lesions are reported. The classic presentation was a breast lump with associated sinus in 39%, isolated breast lump in 23%, sinus without lump in 12%, and tender nodularity in 23% of the patients. Associated axillary lymphadenopathy was found in 41%. Diagnosis was confirmed by fine needle aspiration cytology or histology in all the cases and antitubercular therapy formed the mainstay of treatment.
Seed germination in the Great Basin halophyte Salsola iberica
Authors: Khan M Ajmal , Gul Bilquees , Weber Darrell J
Published: July 2002

Salsola iberica Sennen & Pau, a halophytic forb in the family Chenopodiaceae, is widely distributed in inland salt deserts of Utah and widespread in North America. Experiments were conducted to determine the effects of NaCl and temperature on seed germination and their recovery of germination from saline conditions after being transferred to distilled water. Seeds of S. iberica were germinated at various temperatures and at various salinities in a 12 h light : 12 h dark photoperiod to determine their germinability under these conditions. Increases in NaCl concentration progressively inhibited seed germination. Few seeds germinated at 1000 mM NaCl. Cooler temperatures significantly inhibited germination, while high night (25°C) and high day (35°C) temperature regimes showed higher germination. Rate of germination decreased with an increase in salinity. Germination rate was higher at 2535°C and lower at 515°C temperatures. Seeds were transferred from salt solutions to distilled water after 20 days, and those from low salinities recovered quickly at cooler temperature regimes. Recovery germination percentages substantially decreased with an increase in salinity and temperature.Key words: halophyte, recovery of seed germination, Salsola iberica, salt desert, thermoperiod, Utah.
Annual rings in native and introduced forbs of lower Michigan, U.S.A.
Authors: Dietz Hansjörg , Schweingruber Fritz Hans
Published: July 2002

Almost nothing is known about the presence of annual growth rings in North American perennial herbs and, correspondingly, the age of forbs is also largely unknown. In this study we sampled established individuals of dicotyledonous perennial herbs (60 species) in different habitats in lower Michigan (U.S.A.) and analyzed the main roots for the presence of growth rings in the secondary xylem. Two thirds of the species showed clearly or relatively clearly demarcated growth rings in the root xylem that are most likely annual rings. The anatomical patterns contributing to the delineation of growth rings in the root xylem differed widely, particularly among plant families. These included variations in vessel diameter and vessel density and differences in the presence and extent of tangential bands of fibres or lignified parenchyma, respectively. Among introduced species and in disturbed habitats (meadows, ruderal sites), clearly demarcated growth rings were found more frequently than among native species and in semi-natural and natural habitats (old fields, prairie remnants, open sandy vegetation). While most of the sampled plants were young (2 to 3 years old), the age distribution in the whole sample was relatively wide (2- to 16-year-old plants). Older individuals ([Formula: see text]6 years old) were mainly found in semi-natural and natural habitats. Results indicate that the analysis of annual rings in the root xylem of perennial herbs (herb-chronology) may be widely used as a reconstructive method in plant ecology over extensive geographic areas with seasonal temperate climate. Research into plant invasions may particularly profit from a high proportion of forb species in disturbed habitats that show clearly demarcated annual rings.Key words: age determination, anatomical patterns, annual rings, perennial herbs, population ecology, secondary root xylem.
Amphibole and mica 40Ar/39Ar ages from the Kaipokok and Aillik domains, Makkovik Province, Labrador: towards a characterization of back-arc processes in the Paleoproterozoic
Authors: Culshaw Nicholas , Reynolds Peter , Sinclair Gavin , Barr Sandra
Published: July 2002

We report amphibole and mica 40Ar/39Ar ages from the Makkovik Province. Amphibole ages from metamorphic rocks decrease towards the interior of the province, indicating a first-order pattern of monotonic cooling with progressive migration of the province into a more distal back-arc location. The amphibole data, in combination with muscovite ages, reveal a second-order pattern consisting of four stages corresponding to changing spatial and temporal configurations of plutonism and deformation. (1) The western Kaipokok domain cooled through muscovite closure by 1810 Ma, long after the cessation of arc magmatism. (2) The Kaipokok Bay shear zone, bounding the Kaipokok and Aillik domains, cooled through amphibole closure during 18051780 Ma, synchronous with emplacement of syn-tectonic granitoid plutons. (3) Between 1740 and 1700 Ma, greenschist-facies shearing occurred along the boundary between the Kaipokok domain and Nain Province synchronous with A-type plutonism and localized shearing in the western Kaipokok domain, cooling to muscovite closure temperatures in the Kaipokok Bay shear zone, and A-type plutonism and amphibole closure or resetting in the Aillik domain. (4) In the period 16501640 Ma, muscovite ages, an amphibole age from a shear zone, and resetting of plutonic amphibole indicate a thermal effect coinciding in part with Labradorian plutonism in the Aillik domain. Amphibole ages from dioritic sheets in the juvenile Aillik domain suggest emplacement between 1715 and 1685 Ma. Amphibole ages constrain crystallization of small mafic plutons in the Kaipokok domain (reworked Archean foreland) to be no younger than 16701660 Ma. These ages are the oldest yet obtained for Labradorian plutonism in the Makkovik Province.
"Sudbury Breccia" at Whitefish Falls, Ontario: evidence for an impact origin
Authors: Parmenter Andrew C , Lee Christopher B , Coniglio Mario
Published: July 2002

Sudbury breccias are unusual clastmatrix rock bodies formed in abundance around the Sudbury Igneous Complex, the most obvious manifestation of a major impact event at Sudbury. At Whitefish Falls, ~70 km southwest of Sudbury, similar breccias consisting of clasts of argillite and amphibolite dyke enclosed in a fine-grained matrix of host rock are developed in metamorphosed argillites of the Huronian Supergroup. Pre-brecciation brittle textures in the host argillite and breccia clasts, such as layer-parallel foliation offset by cataclastic fractures, suggest that the host rock was entirely competent prior to brecciation. One composite penetrative foliation and its associated ductile folding were also formed in the argillite host prior to brecciation. Post-brecciation ductile deformation produced a regionally dominant eastwest-trending foliation, and two late-stage folding events, and indicate a syn-Penokean age of brecciation. The breccias at Whitefish Falls are enriched in ferromagnesian minerals compared to adjacent, embayed and partially digested, host rock. Flow-foliated breccia matrices surround a highly rounded clast phase. These features are characteristic of impact-related pseudotachylyte, formed during extreme cataclasis and friction melting of the impacted host rock. We propose that these breccias formed by injection of a high-strain, pseudotachylytic melt, triggered by the Sudbury impact event, and focused along a blind superfault, coincident with a post-Penokean high-strain zone.
Mesozoic thermal history and timing of structural events for the Yukon-Tanana Upland, east-central Alaska: 40Ar/39Ar data from metamorphic and plutonic rocks
Authors: Dusel-Bacon Cynthia , Lanphere Marvin A , Sharp Warren D , Layer Paul W , Hansen Vicki L
Published: July 2002

We present new 40Ar/39Ar ages for hornblende, muscovite, and biotite from metamorphic and plutonic rocks from the YukonTanana Upland, Alaska. Integration of our data with published 40Ar/39Ar, kinematic, and metamorphic pressure (P) and temperature (T) data confirms and refines the complex interaction of metamorphism and tectonism proposed for the region. The oldest metamorphic episode(s) postdates Middle Permian magmatism and predates the intrusion of Late Triassic (215212 Ma) granitoids into the Fortymile River assemblage (Taylor Mountain assemblage of previous papers). In the eastern Eagle quadrangle, rapid and widespread Early Jurassic cooling is indicated by ~188186 Ma 40Ar/39Ar plateau ages for hornblende from plutons that intrude the Fortymile River assemblage, and for metamorphic minerals from the Fortymile River assemblage and the structurally underlying Nasina assemblage. We interpret these Early Jurassic ages to represent cooling resulting from northwest-directed contraction that emplaced the Fortymile River assemblage onto the Nasina assemblage to the north as well as the Lake George assemblage to the south. This cooling was the final stage of a continuum of subduction-related contraction that produced crustal thickening, intermediate- to high-P metamorphism within both the Fortymile River assemblage and the structurally underlying Lake George assemblage, and Late Triassic and Early Jurassic plutonism in the Fortymile River and Nasina assemblages. Although a few metamorphic samples from the Lake George assemblage yield Jurassic 40Ar/39Ar cooling ages, most yield Early Cretaceous 40Ar/39Ar ages: hornblende ~135115 Ma, and muscovite and biotite ~110108 Ma. We interpret the Early Cretaceous metamorphic cooling, in most areas, to have resulted from regional extension and exhumation of the lower plate, previously tectonically thickened during Early Jurassic and older convergence.
Review of crustal architecture and evolution in the Ungava Peninsula — Baffin Island area: connection to the Lithoprobe ECSOOT transect
Authors: St-Onge M R , Scott D J , Wodicka N
Published: July 2002

Within the Trans-Hudson Orogen in northern Quebec and southern Baffin Island, parautochthonous Archean basement and Paleoproterozoic cover, as well as allochthonous (accreted) Paleoproterozoic units, are exposed in a series of antiformal culminations and complementary synclinoria. The parautochthonous rocks of the Superior Province margin and two assemblages of accreted Paleoproterozoic units (Ungava and Meta Incognita crustal terranes) define a basic tripartite crustal architecture which is characterized by polyphase deformation and metamorphic histories. Early structures and mineral assemblages are recognized in all three crustal components and shown to be temporally distinct. The earlier structures and assemblages are overprinted by younger elements and mineral assemblages that are related to at least three regional contraction episodes and one thermal event that are common to all crustal components of the orogen. Close correlation of regional aeromagnetic data in northern Quebec and southern Baffin Island with the three crustal components offers a first-order approximation of the distribution of basement lithological units across Hudson Strait. Continuation of the aeromagnetic domains beneath Ungava Bay to northeastern Quebec and northern Labrador allows for the southward extrapolation of the tripartite Trans-Hudson Orogen crustal architecture into the Lithoprobe Eastern Canadian Shield OnshoreOffshore Transect area.
Predation on marine-phase Atlantic salmon (Salmo salar) by gannets (Morus bassanus) in the Northwest Atlantic
Authors: Montevecchi W A , Cairns D K , Myers R A
Published: July 2002

Predation on Atlantic salmon (Salmo salar) has been recorded in rivers and estuaries, but there is little documentation of predation at sea. Prey landed by gannets (Morus bassanus) over 24 years in a large colony off northeast Newfoundland included small proportions of post-smolt Atlantic salmon. Before 1990, when shifts in oceanographic conditions and pelagic food webs occurred in the Labrador Sea, post-smolts, on average, made up 0.29% of estimated intake by gannets during August 19771989. In contrast, during the 1990s, this estimate increased to 2.53%, peaking at 6.37% in 1993. Model estimates with wide error margins projected that gannets consumed a mean of 1.6 t and 19.2 t of post-smolts during August 19771989 and 19902000, respectively, making up 0.22% and 2.70% of estimated North American post-smolt biomass during these periods. The migratory routes of post-smolt Atlantic salmon pass through the foraging ranges of gannet colonies, but limited sampling at colonies other than Funk has not revealed salmon in gannet diets. Sampling seabird diets is an economic, biological means of investigating the ecology and natural mortality of Atlantic salmon. Spatial and temporal expansion of this sampling would enhance its oceanographic context and reduce uncertainty associated with estimates of predation by seabirds.
Temporal and spatial variability in elemental composition of otoliths: implications for determining stock identity and connectivity of populations
Authors: Gillanders Bronwyn M
Published: July 2002

Interannual variability in elemental composition of otoliths may confound spatial interpretations. The elemental fingerprints of otoliths of juvenile fish were determined for fish collected from 12 to 15 estuaries in each of three consecutive recruitment years to determine temporal variation in otolith chemistry for each estuary. It was also examined whether there is overlap in elemental fingerprints of fish collected in different years and from different estuaries that may confound subsequent spatial comparisons. Significant differences in otolith chemistry were found among years for individual elements (lithium, manganese, strontium, and barium) and for multi-element fingerprints. Some estuaries showed large variation in multi-element fingerprints among years, whereas others showed little variation among years. There was some overlap of elemental fingerprints of different estuaries, but these were not always for fish collected in the same year. The significant spatial and temporal variation in elemental fingerprints meant that it was possible to confound spatial differences with temporal differences. Therefore, if the natal estuary of the adults is to be determined, a library of elemental fingerprints needs to be built up over time for each estuary rather than a single year-class of juveniles being used as the elemental fingerprint for a number of year-classes of adults.
Dynamics of the Lake Michigan food web, 19702000
Authors: Madenjian Charles P , Fahnenstiel Gary L , Johengen Thomas H , Nalepa Thomas F , Vanderploeg Henry A , Fleischer Guy W , Schneeberger Philip J , Benjamin Darren M , Smith Emily B , Bence James R , Rutherford Edward S , Lavis Dennis S , Robertson Dale M , Jude David J , Ebener Mark P
Published: July 2002

Herein, we document changes in the Lake Michigan food web between 1970 and 2000 and identify the factors responsible for these changes. Control of sea lamprey (Petromyzon marinus) and alewife (Alosa pseudoharengus) populations in Lake Michigan, beginning in the 1950s and 1960s, had profound effects on the food web. Recoveries of lake whitefish (Coregonus clupeaformis) and burbot (Lota lota) populations, as well as the buildup of salmonine populations, were attributable, at least in part, to sea lamprey control. Based on our analyses, predation by salmonines was primarily responsible for the reduction in alewife abundance during the 1970s and early 1980s. In turn, the decrease in alewife abundance likely contributed to recoveries of deepwater sculpin (Myoxocephalus thompsoni), yellow perch (Perca flavescens), and burbot populations during the 1970s and 1980s. Decrease in the abundance of all three dominant benthic macroinvertebrate groups, including Diporeia, oligochaetes, and sphaeriids, during the 1980s in nearshore waters ([Formula: see text]50 m deep) of Lake Michigan, was attributable to a decrease in primary production linked to a decline in phosphorus loadings. Continued decrease in Diporeia abundance during the 1990s was associated with the zebra mussel (Dreissena polymorpha) invasion, but specific mechanisms for zebra mussels affecting Diporeia abundance remain unidentified.
Procedures for recovering mesospheric and stratospheric temperatures from OSIRIS scattered-sunlight measurements
Authors: Haley C S , McDade I C
Published: July 2002

Procedures for recovering mesospheric and stratospheric temperature profiles from scattered-sunlight limb radiance measurements made by the OSIRIS (optical spectrograph and infrared imager system) instrument on the Odin satellite are described. We assess various approaches to the problem and show that temperature recoveries based on an analysis of inferred volume-scattering rates are significantly more accurate than those based on direct analysis of the observed limb radiances. A forward model for the OSIRIS instrument is used to test temperature recovery algorithm performance in the presence of realistic instrument noise and to assess the expected accuracy of the OSIRIS temperature recoveries. It is shown that, for radiances measured in the near-infrared region, temperatures can be reliably recovered over the altitude range 40 km to 80 km with an accuracy of better than ±1 K.

PACS Nos.: 42.68Mj, 94.10Dy
An overview of the Odin atmospheric mission
Authors: Murtagh D , Frisk U , Merino F , Ridal M , Jonsson A , Stegman J , Witt G , Eriksson P , Jiménez C , Megie G , Noë J de la , Ricaud P , Baron P , Pardo J R , Hauchcorne A , Llewellyn E J , Degenstein D A , Gattinger R L , Lloyd N D , Evans W FJ , McDade I C , Haley C S , Sioris C , Savigny C von , Solheim B H , McConnell J C , Strong K , Richardson E H , Leppelmeier G W , Kyrölä E , Auvinen H , Oikarinen L
Published: July 2002

Odin is a 250 kg class satellite built in co-operation between Sweden, Canada, France, and Finland and launched in February 2001. It carries two instruments: a 4-band sub-millimetre radiometer used for both astronomy and atmospheric science and an optical spectrometer and infrared imaging system for purely atmospheric observations. As part of the joint mission Odin will observe the atmospheric limb for 50% of the observation time producing profiles of many species of interest in the middle atmosphere with a vertical resolution of 12 km. These species include, among others, ozone, nitrogen dioxide, chlorine monoxide, nitric acid, water vapour, and nitrous oxide. An overview of the mission and the planned measurements is given.

PACS Nos.: 42.68Mj, 94.10Dy, 95.55Fw
Chloroperoxidase-catalyzed oxidation of methionine derivatives
Authors: Holland Herbert L , Brown Frances M , Lozada Damian , Mayne Benjamin , Szerminski W Rick , van Vliet Aaron J
Published: July 2002

Treatment of N-methoxycarbonyl C-carboxylate ester derivatives of L- and D-methionine and L-ethionine by chloroperoxidasehydrogen peroxide resulted in oxidation at sulfur to produce the (RS) sulfoxide in moderate to high diastereomeric excess. The (RS) sulfoxide of methionine was also obtained in moderate to high diastereomeric excess from (±)SO-N-methoxycarbonyl-L-methionine methyl ester sulfoxide by ester hydrolysis using α-chymotrypsin, Aspergillus sp. protease or subtilisin Carlsberg. Key words: amino acid oxidation, biocatalysis, biotransformation, chloroperoxidase, enzyme catalysis, lipase, sulfoxidation.
Discriminating between dispersion and lyoprotection effects in biocatalysis in organic media
Authors: Secundo Francesco , Carrea Giacomo , Veronese Francesco Maria
Published: July 2002

The increment of activity and solubility in 1,4-dioxane of lipase B from Candida antarctica, lipase from Pseudomonas cepacia, and subtilisin, were investigated as a function of the methoxypoly(ethylene glycol)protein (PEGprotein) ratio employed during lyophilization. Both activity and solubility markedly increased as the PEGprotein ratio was increased. The increment of activity at low PEGprotein ratios, however, was much higher than that of solubility. These data suggest that the PEG-induced activation effect is due mainly to a lyoprotection effect rather than to relaxation of diffusional limitations.Key words: hydrolases, activity, dispersion, lyoprotection, circular dichroism.
Baeyer-Villiger oxidations catalyzed by engineered microorganisms: Enantioselective synthesis of δ-valerolactones with functionalized chains
Authors: Wang Shaozhao , Chen Gang , Kayser Margaret M , Iwaki Hiroaki , Lau Peter C.K , Hasegawa Yoshie
Published: July 2002

Cyclohexanone monooxygenase (CHMO) from Acinetobacter sp NCIMB 9871 expressed in baker's yeast and in E. coli and cyclopentanone monooxygenase (CPMO) from Comamonas (previously Pseudomonas) sp. NCIMB 9872 expressed in E. coli are new bioreagents for Baeyer-Villiger oxidations. These engineered microorganisms, requiring neither biochemical expertise nor equipment beyond that found in chemical laboratories, were evaluated as reagents for Baeyer-Villiger oxidations of cyclopentanones substituted at the 2-position with polar and nonpolar chains suitable for further modifications. Two such functionalized substrates that can be transformed into highly enantiopure lactones were identified. The performance and the potential of these bioreagents are discussed.Key words: enantioselective Baeyer-Villiger oxidations, biotransformations, cyclohexanone monooxygenase, cyclo pentanone monooxygenase, engineered baker's yeast, recombinant E. coli, optically pure 2-substituted cyclopentanones, optically pure lactones.