bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased Production of Interleukin-8 in Primary Human Monocytes and in Human Epithelial and Endothelial Cell Lines after Dengue Virus Challenge
Authors: Bosch Irene , Xhaja Kris , Estevez Luis , Raines Gregory , Melichar Heather , Warke Rajas V. , Fournier Marcia V. , Ennis Francis A. , Rothman Alan L.
Published: July 2002

The more severe form of dengue virus infection, dengue hemorrhagic fever, is characterized by plasma leakage and derangements in hemostasis. As elevated interleukin-8 (IL-8) levels have been observed in sera from patients with more severe disease manifestations, a study was initiated to look at the effect of dengue virus infection in vitro on proinflammatory cytokine secretion and expression. A significant increase in IL-8 levels in the culture supernatant of primary human monocytes infected with dengue 2 virus (D2V) New Guinea C (NGC) was found by enzyme-linked immunosorbent assay. Additionally, by reverse transcriptase PCR, the mRNA was also augmented. Among the proinflammatory cytokines and their mRNAs measured (IL-6, IL-1β, IL-8, and tumor necrosis factor alpha), IL-8 showed the greatest change following D2V infection. Similarly, two cell lines, 293T (a human epithelial cell line) and ECV304 (an endothelial cell line), were permissive to D2V NGC and responded to the infection by increasing the synthesis of IL-8. Nuclear factor kappa B (NF-κB) and nuclear factor IL-6 (NFIL-6) are primary mediators of IL-8 expression. We studied the transcriptional regulation of IL-8 in the ECV304 and 293T cell lines and found that the induction of IL-8 gene expression involved the activation of NF-κB (P= 0.001) and, to a lesser extent, the activation of NFIL-6 in ECV304 cells only. We next observed by the chromatin immunoprecipitation procedure in vivo acetylation of core histones bound to the IL-8 promoter after D2V infection. IL-8 produced by infected monocytes and also IL-8 that may be produced by endothelial or other epithelial cells is associated with the hyperacetylation of histones bound to the IL-8 promoter in addition to the activation of transcription by NF-κB. We hypothesize that the overall increase in IL-8 synthesis observed in this in vitro study may play a role in the pathogenesis of the plasma leakage seen in dengue hemorrhagic fever and dengue shock syndrome.
U
S
3 Protein Kinase of Herpes Simplex Virus 1 Blocks Caspase 3 Activation Induced by the Products of U
S
1.5 and U
L
13 Genes and Modulates Expression of Transduced U
S
1.5 Open Reading Frame in a Cell Type-Specific Manner
Authors: Hagglund Ryan , Munger Joshua , Poon Alice P. W. , Roizman Bernard
Published: July 2002

The coding domain of the herpes simplex virus type 1 (HSV-1) α22 gene encodes two proteins, the 420-amino-acid infected-cell protein 22 (ICP22) and U
S
1.5, a protein colinear with the carboxyl-terminal domain of ICP22. In HSV-1-infected cells, ICP22 and U
S
1.5 are extensively modified by the U
L
13 and U
S
3 viral protein kinases. In this report, we show that in contrast to other viral proteins defined by their properties as α proteins, U
S
1.5 becomes detectable and accumulated only at late times after infection. Moreover, significantly more U
S
1.5 protein accumulated in cells infected with a mutant lacking the U
L
13 gene than in cells infected with wild-type virus. To define the role of viral protein kinases on the accumulation of U
S
1.5 protein, rabbit skin cells or Vero cells were exposed to recombinant baculoviruses that expressed U
S
1.5, U
L
13, or U
S
3 proteins under a human cytomegalovirus immediate-early promoter. The results were as follows. (i) Accumulation of the U
S
1.5 protein was reduced by concurrent expression of the U
L
13 protein kinase and augmented by concurrent expression of the U
S
3 protein kinase. The magnitude of the reduction or increase in the accumulation of the U
S
1.5 protein was cell type dependent. The effect of U
L
13 kinase appears to be specific inasmuch as it did not affect the accumulation of glycoprotein D in cells doubly infected by recombinant baculoviruses expressing these genes. (ii) The reduction in accumulation of the U
S
1.5 protein was partially due to proteasome-dependent degradation. (iii) Both U
S
1.5 and U
L
13 proteins activated caspase 3, indicative of programmed cell death. (iv) Concurrent expression of the U
S
3 protein kinase blocked activation of caspase 3. The results are concordant with those published elsewhere (J. Munger and B. Roizman, Proc. Natl. Acad. Sci. USA 98:10410–10415, 2001) that the U
S
3 protein kinase can block apoptosis by degradation or posttranslational modification of BAD.
The Herpes Simplex Virus Type 1 U
S
11 Protein Interacts with Protein Kinase R in Infected Cells and Requires a 30-Amino-Acid Sequence Adjacent to a Kinase Substrate Domain
Authors: Cassady Kevin A. , Gross Martin
Published: July 2002

The herpes simplex virus type 1 γ
1
34.5 gene product precludes the host-mediated protein shutoff response induced by activated protein kinase R (PKR). Earlier studies demonstrated that recombinant viruses lacking the γ
1
34.5 gene (Δγ
1
34.5) developed secondary mutations that allowed earlier U
S
11 expression and enabled continued protein synthesis. Further, in vitro studies demonstrated that a recombinant expressed U
S
11 protein binds PKR, blocks the phosphorylation of the α subunit of eukaryotic initiation factor 2 (eIF-2α) by activated PKR, and, if provided prior to PKR activation, precluded PKR autophosphorylation. The present study furthers the hypothesis that early U
S
11 production precludes PKR-mediated host protein shutoff by demonstrating that (i) U
S
11 and PKR interact in the context of viral infection, (ii) this interaction is RNA dependent and requires a 30-amino-acid domain (amino acids 91 to 121) in the carboxyl domain of the U
S
11 protein, (iii) the proteins biochemically colocalize in the S100 ribosomal fraction, and (iv) there is a PKR substrate domain immediately adjacent to the binding domain. The results suggest that the U
S
11 interaction with PKR at the ribosome is RNA dependent and that the U
S
11 protein contains a substrate domain with homology to eIF-2α in close proximity to an essential binding domain.
Pathogenesis of Herpes Simplex Virus Type 2 Virion Host Shutoff (vhs) Mutants
Authors: Smith Tracy J. , Morrison Lynda A. , Leib David A.
Published: July 2002

During lytic infection, the virion host shutoff (vhs) protein mediates the rapid degradation of mRNA and the shutoff of host protein synthesis. In vivo, herpes simplex virus type 1 (HSV-1) mutants lackingvhsactivity are profoundly attenuated. Homologs ofvhsexist in all of the neurotropic herpesviruses, and the goal of this study was to determine the virulence of HSV-2 mutants lacking vhs. Two HSV-2 recombinants were used in this study: 333-vhsB, which has alacZcassette inserted into the N terminus ofvhs, and 333d41, which has a 939-bp deletion invhs. As expected, both 333-vhsB and 333d41 failed to induce the cellular RNA degradation characteristic of HSV. Corneal, vaginal, and intracerebral routes of infection were used to study pathogenesis. Both viruses grew to significantly lower titers in the corneas, trigeminal ganglia, vaginas, dorsal root ganglia, spinal cords, and brains of mice than wild-type and rescue viruses, with a correspondingly reduced induction of disease. Both viruses, however, reactivated efficiently from explanted trigeminal ganglia, showing thatvhsis dispensable for reactivation. The lethality of 333d41 following peripheral infection of mice, however, was significantly higher than that of 333-vhsB, suggesting that some of the attenuation of 333-vhsB may be due to the presence of alacZcassette in thevhslocus. Taken together, these data show thatvhsrepresents an important determinant of HSV-2 pathogenesis and have implications for the design of HSV-2 recombinants and vaccines.
Identification of Human Herpesvirus 6 Latency-Associated Transcripts
Authors: Kondo Kazuhiro , Shimada Kazuya , Sashihara Junji , Tanaka-Taya Keiko , Yamanishi Koichi
Published: July 2002

Four kinds of latency-associated transcripts of human herpesvirus 6 were identified which were detected only in latently infected cells. Although they were oriented in the same direction as the immediate-early 1 and 2 (IE1/IE2) genes and shared their protein-coding region with IE1/IE2, their transcription start sites and exon(s) were latency associated.
The Effect of the Molecular Structure of Cyanine Dye on the Corrosion of Low-Carbon Steel in Hydrochloric Acid Solution
Authors: Makhlouf Mohamed Th.
Published: July 2002

The effect of two different cyanine dyes 2-(2-hydroxystyryl)quinolinium-1-ethyl iodide (I) and 4-(2-hydroxystyryl)quinolinium-1-ethyl iodide (II) on the electrochemical corrosion behaviour of low-carbon steel (0.05% C, 0.04% Si, 0.023% S, 0.004% Cu) in HCl solution has been studied. Weight loss measurements, galvanostatic polarization curves, open-circuit potential variation of steel electrode with time and the cathodic protective current values show that the investigated cyanine dyes have an anticorrosive character. The inhibition effect depends mainly on the structure of the studied dye molecules, and is more pronounced in case of pretreated carbon steel with the dye solution before immersion in the corrosion medium than that obtained by addition of the dye to the corrosive medium.
Preparation, 1H and 13C NMR Spectra of Substituted 2-Benzoylaminocarboxamides
Authors: Sedlák Miloš , Halama Aleš , Kaválek Jaromír , Macháček Vladimír , Štěrba Vojeslav
Published: July 2002

A new type of herbicides based on imidazolinones has been introduced into agriculture under commercial names of Arsenal, Pursuit, Scepter, Assert etc. by American Cyanamid Company since 1983. These compounds destroy diocotyledonous weeds and are almost nontoxic for mammals and fish (LD50 rat - 500 mg/kg, LD50 trout - 300 mg/kg) and nonmutagenic according to the AMES test. The aim of the present work is to synthesize substituted 2-benzoylaminocarboxamides as starting materials for preparation of imidazolinones and potential biologically active substances (Formulae I - III).
Studies of a Mixed Adsorption Layer of n-Butanol and m- and p-Toluidine on Mercury Electrode
Authors: Saba Jadwiga
Published: July 2002

The mixed adsorption layers of n-butanol-m-toluidine and n-butanol-p-toluidine were studied and the surface excess of pure components and their mixtures was determined. The occurrence of synergetic coadsorption was observed. The rate constants of Zn(II) ion reduction were determined in 1 mol l-1 NaClO4 in presence of n-butanol as an inhibitor, m- and p-toluidine as accelerating substances and in their mixtures. It was found that the inhibiting or accelerating effect depends on the concentration of n-butanol and m- or p-toluidine. Compensation of these effects achieved at the concentration ratio of CBU : CpT ~ 35 and CBU : CmT ~ 85 in a wide concentration range is an evidence of toluidine predominance in the formation of a mixed adsorption layer.
Association of Graft Copolymers of Alkyl Methacrylates with α-Methyl-ω-hydroxy-poly(oxyethylene) ethacrylates
Authors: Koňák Čestmír , Tuzar Zdeněk , Kopečková Pavla , Andrade Joseph D. , Kopeček Jindřich
Published: July 2002

Solution properties of the statistical copolymers of alkyl methacrylates (AMA) with α-methyl-ω-hydroxy-poly(oxyethylene) methacrylates (MPOEMA) (nonionic polysoaps) were studied using static and dynamic ligh scattering as a function of monomer composition and concentration in aqueous and methyl cellosolve solutions. The solubility of the copolymers in water was found to be dependent on molar contant of AMA. While copolymers with low content of hexyl methacrylate (HMA) (0 and 20 mole %) were directly soluble in water, forming true solutions with a low content of large swollen aggregates, copolymers with a higher content of HMA or lauryl methacrylate (LMA) were not directly dispersable in water. A special procedure, the stepwise dialysis from methyl cellosolve solutions against water, had to be used to prepare them in the pseudomicellar form. The copolymers were directly soluble in methyl cellosolve and its water solution containing up to 60 vol.% of water. Nevertheless, the light scattering experiments were dominated by light scattering of swollen particles of aggregated copolymer molecules. The copolymers were not soluble in the mixtures containing 70-100 vol.% of water. Paramaters of aggregates in the mixture with 60 vol.% of water and in pure water were found to be very similar.
Dissociation of Amides in Strongly Basic Medium of Sodium Methoxide in Dimethyl Sulfoxide-Methanol Mixtures
Authors: Mitaš Petr , Kaválek Jaromír , Pytela Oldřich
Published: July 2002

The dissociation constants of eleven amides have been measured in methanol and its mixtures with dimethyl sulfoxide (10 to 80% v/v) using sodium methoxide as the base. The experimental dissociation constants have been used to construct the H- acidity function as a function of methoxide concentration and composition of the DMSO-MeOH mixture as well as function of methoxide concentration in methanol. Moreover, with the help of construction of acidity function, the functions have been devised for constant sodium methoxide concentrations (0.025, 0.1, and 0.2 mol l-1) and changing composition of the DMSO-MeOH mixture.
Electroreductive Additions of Aromatic Dichalcogenides to Fluorinated Ethenes
Authors: Dvořák David , Neugebauerová Eva , Liška František , Ludvík Jiří
Published: July 2002

Intermediates and products formed during the electrochemical reduction of diphenyl disulfide (1) add to chlorotrifluoroethene (3) under the formation of 2-chloro-1,1,2-trifluoroethyl phenyl sulfide (5) and the E/Z isomers of 2-chloro-1,2-difluoroethenyl phenyl sulfide (6). The analogous reaction with 1,2-dichlorodifluoroethene (4) led to a mixture of E/Z isomers of 6. Electrochemically reduced diphenyl diselenide (2) reacted with 3 giving rise to 2-chloro-1,1,2-trifluoroethyl phenyl selenide (7) whereas the reaction with 4 does not proceed. Addition of disulfide 1 to 4 gives evidence of the participation of the radical PhS.. With diselenide 2, an analogous radical addition reaction was not observed. This is consistent with other experiments suggesting different mechanisms of reductive cleavage of the S-S and Se-Se bonds and the absence of radicals PhSe. in the latter.
15N, 13C, and 1H NMR Spectra of Azo and Hydrazo Compounds Derived from 1,3,3-Trimethyl-2-methylidene-2,3-dihydroindole (Fischer Base)
Authors: Lyčka Antonín , Jirman Josef , Koloničný Alois
Published: July 2002

The 15N, 13C, and 1H NMR spectra were measured for azo and hydrazo compounds derived from 1,3,3-trimethyl-2-methylidene-2,3-dihydroindole (Fischer base), which is a passive component with a terminal methylidene group. Products prepared by coupling in hydrochloric acid exist in the corresponding hydrazone form as the E-isomers. Neutralization gives a mixture of two isomeric azo compounds which differ in the arrangement at the C(2)=C(10) double bond. This mixture was alkylated with methyl iodide to obtain the =N-N(CH3)- hydrazone derivatives. The geometric isomers were resolved based on the NOESY approach and the stereospecific behaviour of the 2J(15N,13C) coupling constants was studied for the 15N-labelled compounds.
Studies on the Mechanism of Antiglucocorticoid Action of 7α-Hydroxydehydroepiandrosterone
Authors: Stárka Luboslav , Hill Martin , Hampl Richard , Malewiak Marie-Irène , Benalycherif Aïda , Morfin Robert , Kolena Jaroslav , Scsuková Sona
Published: July 2002

The literature reports that 7α-hydroxydehydroepiandrosterone (7α-OH-DHEA), a metabolite of dehydroepiandrosterone (DHEA), displays numerous anti-aging properties (such as immunostimulation and anti-apoptotic effects) which may result from an apparent antiglucocorticoid activity. However, the molecular mechanism(s) of this effect remain to be elucidated. In the present work, we attempted to unravel some aspects of this mechanism in vitro, in adrenalectomized rats. No specific binding of [3H]-7α-OH-DHEA occurred with the hepatic cytosolic fraction, and the binding of [3H]-dexamethasone ([3H]-DEX) to the cytosolic glucocorticoid receptor complex (GCRC) was unaffected by increasing concentrations of either DHEA or 7α-OH-DHEA. In marked contrast, in isolated hepatic nuclei, the retention of partially purified [3H]-DEX-labelled cytosolic GCRC was significantly decreased after nuclei preincubation with 7α-OH-DHEA, DHEA or 7α-hydroxypregnenolone. However, further experiments using isolated cytosolic fraction preactivated with [3H]-DEX and then filtered on DNA-cellulose columns in the presence or in the absence of 7α-hydroxy steroids unequivocally demonstrated that 7α-OH-DHEA neither competed with the activation of the GCRC, nor inhibited the binding of this complex to DNA-cellulose in the cell-free system. The effect of 7α-OH-DHEA on membrane fluidity of brain cell membranes was observed only at concentrations higher that that of the parent substance DHEA. Thus, the effect of 7α-OH-DHEA does not seem to be mediated by the influence of the accessibility of the hormone to intracellular receptors. While the GCRC binding to DNA is apparently unaffected by 7α-OH-DHEA, and cannot therefore explain the lesser retention of DEX-activated GCRC in isolated nuclei, other mechanisms, possibly extranuclear, such as modification of the conformation of GCRC may be involved. The GCRC in the presence of 7α-OH-DHEA, may account for the antiglucocorticoid properties of this steroid which are currently under investigation.
Crystal Structures of Cyclosporin Derivatives: O-Acetyl-(4R)-4-(E-2-butyl)-4,N-dimethyl-L-threonyl-cyclosporin A and O-Acetyl-(4R)-4-[E-2-(4-bromobutyl)]-4,N-dimethyl-L-threonyl-cyclosporin A
Authors: Kratochvíl Bohumil , Jegorov Alexandr , Pakhomova Svetlana , Hušák Michal , Bulej Petr , Cvak Ladislav , Sedmera Petr , Havlíček Vladimír
Published: July 2002

The structures of O-acetyl-(4R)-4-(E-2-butyl)-4,N-dimethyl-L-threonyl-cyclosporin A (1) and O-acetyl-(4R)-4-[E-2-(4-bromobutyl)]-4,N-dimethyl-L-threonyl-cyclosporin A (2) were determined by X-ray diffraction methods and compared with the structure of related cyclosporins. In contrast to expectation, neither the acetylation nor the subsequent bromination of 1 affects the conformation and packing of cyclosporins in the solid state. Both compounds are isomorphous and crystallize in the orthorhombic space group P212121 with a = 12.936(2) Å, b = 15.590(2) Å, c = 36.280(3) Å, and a = 12.916(3) Å, b = 15.675(4) Å, c = 36.715(7) Å, for 1 and 2, respectively.
Facile Synthesis of 6-Aryl-1,3-dimethyl-5H-pyrimido[4,5-b][1,4]diazepine-2,4(1H,3H)-diones
Authors: Taghavi-Moghadam Shahriyar , Stumpf Rüdiger , Fischer Helmut , Pfleiderer Wolfgang
Published: July 2002

A facile procedure for the preparation of 6-aryl-1,3-dimethyl-5H-pyrimido[4,5-b][1,4]diazepine2,4(1H,3H)-diones 8, 9 from 6-amino-5-arylideneamino-1,3-dimethyluracils 1, 2 and triethyl orthoacetate (3) in a two-step reaction via 6-aryl-8-ethoxy-6,7-dihydro-1,3-dimethyl-5H-pyrimido[4,5-b][1,4]diazepine-2,4(1H,3H)-diones 6, 7 is described. Condensation of 1 with diethoxymethyl acetate (10) resulted in the formation of (1,3-dimethyl-2,6-(1H,3H)-dioxopurin-7-yl)(phenyl)methyl acetate (11) and a small amount of 1,3-dimethyl-6-phenylpyrazino[2,3-d]pyrimidine-2,4(1H,3H)-dione (12). The structures of 6 and 11 were unambiguously confirmed by single-crystal X-ray diffraction analysis.
Kinetics of Base-Catalysed Hydrolysis and Cyclisation of Substituted Acetamide and Benzamide O-(Phenoxycarbonyl)oximes
Authors: Mindl Jaromír , Kaválek Jaromír , Straková Helena , Štěrba Vojeslav
Published: July 2002

The reaction kinetics of acetamide O-(4-nitrophenoxycarbonyl)oxime have been studied in aqueous buffers at pH 2-11. At pH > 9, the pH dependence of kobs is linear with slope 1, the cyclisation to 3-methyl-1,2,4-oxadiazol-5(4H)-one and 4-nitrophenol being the only reaction. At pH < 7.5, the only reaction is the hydrolysis giving 4-nitrophenol and acetamidoxime. The dependence of kobs on pH has been used to determine the rate equation and to propose the reaction mechanism. The cyclisation kinetics of substituted benzamide O-(phenoxycarbonyl)oximes have been studied in the pH range from 9.25 to 11. The reaction mechanism has been proposed based on the ρ constants found. In the first reaction step, the proton is split off from the NH2 group; the subsequent, rate-limiting step involves simultaneous N-C bond formation and C-O bond splitting.
Radical Intermediates in Electrochemical Polymer-Forming Reactions
Authors: Holze Rudolf
Published: July 2002

The role of organic radicals in the formation of functional polymers, in particular intrinsically conducting polymers, is reviewed. New results recently obtained within situspectroscopic methods illustrating the influence of the molecular structure of monomers (aniline and substituted anilines) in the behaviour of radical intermediates are presented. The stabilising influence of substituents at various positions of the aniline molecule is evaluated and compared based on conceivable structures of reaction intermediates.
Effect of the Purine Derivative Myoseverin and of Its Analogues on Cultured Hybridoma Cells
Authors: Franěk František , Siglerová Věra , Havlíček Libor , Strnad Miroslav , Eckschlager Tomáš , Weigl Evžen
Published: July 2002

Two 2,6,9-trisubstituted purine derivatives, 9-isopropyl-2,6-bis[(4-methoxybenzyl)amino]-9H-purine (myoseverin, PMYO, 1) and 9-isopropyl-2,6-bis[(2-methoxybenzyl)amino]-9H-purine (OMYO, 2), and two 6,9-disubstituted derivatives, 9-isopropyl-6-[(4-methoxybenzyl)amino]-9H-purine (3) and 9-isopropyl-6-[(2-methoxybenzyl)amino]-9H-purine (4), were synthesized with the aim to examine their cell proliferation inhibiting activity, and possible additional effects in cultures of hybridoma cells producing monoclonal antibody. The substances were tested over a concentration range from 0.003 to 30 μmol l-1. The most active compound 1 caused a total loss of cell viability at 1 μmol l-1, while its isomer 2 showed the same effect at 10 μmol l-1 concentration. In the presence of compound 1, but not of compound 2, the character of the cell cycle phases profile changed dramatically, most cells being arrested in the G2/M phase. At intermediate concentrations of compound 2 a substantially higher viable cell concentration was observed, relative to control. These differences demonstrated the principal significance of the position of the methoxy groups on the benzene rings for the biological effect. The 6,9-disubstituted derivatives 3 and 4 were without significant effect in the whole range of concentrations tested. The enhancement of monoclonal antibody production, observed in certain concentration intervals of added substances, was of marginal character.
Crystal Forms of Semisynthetic Ergot Alkaloid Terguride
Authors: Hušák Michal , Kratochvíl Bohumil , Císařová Ivana , Cvak Ladislav , Jegorov Alexandr , Böhm Stanislav
Published: July 2002

Two new structures of semisynthetic ergot alkaloid terguride created by unusual number of symmetry-independent molecules were determined by X-ray diffraction methods at 150 K. Form A (monoclinic, P212121, Z = 12) contains three symmetry-independent terguride molecules and two molecules of water in the asymmetric part of the unit cell. The form CA (monoclinic, P21, Z = 8) is an anhydrate remarkable by the presence of four symmetry-independent molecules in the crystal structure. Conformations of twelve symmetry-independent molecules that were found in four already described terguride structures are compared with torsion angles obtained by ab initio quantum-mechanical calculations for the simplified model of N-cyclohexyl-N'-diethylurea.
Autoantigens in primary biliary cirrhosis
Authors: Jones D E J
Published: July 2002

The automimmune liver disease primary biliary cirrhosis (PBC) is characterised by serum autoantibodies directed at mitochondrial and nuclear antigens (seen in most patients and a subset of patients, respectively). The antimitochondrial antibodies (AMA) characteristic of PBC are directed at members of the 2-oxoacid dehydrogenase components of multienzyme complexes; in particular, the E2 and E3 binding protein (E3BP) components of the pyruvate dehydrogenase complex (PDC). The presence of autoantibodies reactive with PDC-E2 and/or E3BP is strongly predictive of the presence of PBC. Therefore, the detection of these antibodies plays a very important role in the diagnosis of PBC. Originally demonstrated using immunofluorescence approaches, AMA can now be detected by the use of commercially available enzyme linked immunosorbent assays (ELISAs). Although the ELISA based approaches have advantages in terms of laboratory practicality, they are slightly less sensitive for the diagnosis of PBC than immunofluorescence (occasional patients with PBC show reactivity with PDC related antigens not present in the antigen preparations available for use with ELISA). Therefore, immunofluorescence should continue to be available as a complementary diagnostic test for use in occasional patients. In a subset of patients with PBC, autoantibodies are directed at increasingly well characterised nuclear antigens. Antinuclear antibody (ANA) positive patients are typically AMA negative. There are no significant differences in disease phenotype between AMA positive and AMA negative groups. At present, the clinical detection of ANA is mostly by Hep2 immunofluorescence, although ELISA kits for individual nuclear antigens are increasingly becoming available.
Self reported symptoms and inhibition of acetylcholinesterase activity among Kenyan agricultural workers
Authors: Ohayo-Mitoko Grace J A , Kromhout Hans , Simwa James M , Boleij Jan S M , Heederik Dick
Published: July 2002

OBJECTIVES

This study was part of the East African pesticides project. The general objective was to assess health hazards posed by handling, storage, and use of pesticides, on agricultural estates and small farms with a view to developing strategies for prevention and control of pesticide poisoning. The aim of this paper is to describe the prevalence of symptoms in this population, to relate levels of inhibition to reported symptoms and evaluate at which levels of inhibition symptoms become increased.

METHODS

Complete data were available for 256 exposed subjects and 152 controls from four regions in Kenya. A structured questionnaire on symptoms experienced at the time of interview was given to all subjects and controls. Information was also obtained on sex, age, main occupation, and level of education. Symptoms reported during the high exposure period, were initially clustered in broader symptom categories from reference literature on health effects of pesticides that inhibit cholinesterase (organophosphate and carbamate). Prevalence ratios were estimated for symptoms with changes in cholinesterase activity in serum.

RESULTS

Symptom prevalence in exposed subjects was higher during the high exposure period than the low exposure period, although these differences were not significant. Interestingly, a clear and significant change in symptoms prevalence was found in the controls with a higher prevalence in the low exposure period. Analysis of the relation between cholinesterase inhibition and symptoms showed that prevalence ratios were significantly >1 for respiratory, eye, and central nervous system symptoms for workers with >30% inhibition. Similar results were found for analyses with the actual level of acetylcholinesterase activity.

CONCLUSION

The results suggest the presence of a relation between exposure and acetylcholinesterase inhibition, acetylcholinesterase activity, and respiratory, eye, and central nervous system symptoms. Increased symptom prevalence was found at acetylcholinesterase activities generally considered to be non-adverse.
Serial perfusion brain tomographic scans detect reversible focal ischaemia in Rasmussen's encephalitis
Authors: Vinjamuri Sobhan , Leach J P , Hart I K
Published: July 2002

A 39-year-old man with advanced adult-onset Rasmussen's encephalitis was treated with prednisolone and long-term, high-dose, human intravenous immunoglobulin. A pretreatment, semiquantitative interictal brain perfusion single photon emission computed tomography (SPECT) scan using 99Tcm HMPAO (hexamethylene propylene amine oxime) showed hypoperfusion in the clinically affected right frontal, parietal and temporal lobes and contralateral perfusion defects. A second scan 8 months later revealed significant improvements (more than two standard deviations) in perfusion of the right frontal and temporal lobes despite serial magnetic resonance imaging evidence of permanent brain damage. This was associated with useful recovery of the patient's physical and cognitive function. We conclude that serial perfusion brain SPECT scanning is a useful method to demonstrate improvement in patients with Rasmussen's encephalitis in response to therapy.
Audit of the investigation of iron deficiency anaemia in a district general hospital, with sample guidelines for future practice
Authors: Willoughby J M T , Laitner S M
Published: July 2002

Iron deficiency anaemia commonly presents in patients who are asymptomatic. In the absence of published guidelines the search for a cause in such cases is frequently uncoordinated, and risks delay in the diagnosis of pathologies requiring urgent attention. This audit was undertaken to determine how thoroughly patients referred to the gastrointestinal unit in a district general hospital between 1990 and 1995 had been investigated, and to draw up guidelines for future practice on the basis of its results. From the case notes of 334 patients examined endoscopically for anaemia 126 were identified as having both proved iron deficiency and a lack of clinical pointers to its cause. The percentage and details of diagnoses made during initial study and a median follow up period of 28 months were ascertained, together with the certified diagnoses of patients who had died. A cause of iron deficiency was identified in 48 (38%) of patients, 22 with cancer. Ten others received a diagnosis during follow up, of whom three died from the condition to which their anaemia had been attributed. Death certificates supplied diagnoses of potential relevance in three further cases. The main gaps in endoscopic coverage consisted of omitting duodenal biopsy or colonoscopy after negative upper gastrointestinal endoscopy. Moreover, diagnosis of certain extraintestinal pathologies, including cancers, was sometimes delayed for lack of liaison between gastroenterologists and other specialists. These and other points have been addressed in the guidelines now proposed.
Pathophysiological and clinical aspects of breathing after stroke
Authors: Howard R S , Rudd A G , Wolfe C D , Williams A J
Published: July 2002

Stroke may disrupt breathing either by (A) causing a disturbance of central rhythm generation, (B) interrupting the descending respiratory pathways leading to a reduced respiratory drive, or (C) causing bulbar weakness leading to aspiration.
Peritoneal encapsulation: a preoperative diagnosis is possible
Authors: Naraynsingh V , Maharaj D , Singh M , Ramdass M J
Published: July 2002

Peritoneal encapsulation is an exceedingly rare developmental abnormality in which the small intestine is encased in an accessory peritoneal sac between the omentum and mesocolon. Two clinical signs associated with the dense fibrous layer encapsulating the intestine are described. The first is a fixed, asymmetrical distension of the abdomen, which does not vary with peristaltic activity due to the unvarying position of the fibrous capsule. The second is the difference in the consistency of the abdominal wall to palpation. The flat area is firm, due to the dense fibrous capsule and the distended area soft, due to the thin walled distended small intestine with no overlying fibrous layer.
Fruit structure of Hippophae rhamnoides cv. Indian Summer (sea buckthorn)
Authors: Harrison J E , Beveridge T
Published: July 2002

Sea buckthorn (Hippophae rhamnoides L.) (Elaeagnaceae) has become of interest as a crop because of the nutritive qualities of its fruit. In this study, structural features of the fruit of H. rhamnoides ssp. cv. Indian Summer were examined by light microscopy. Additional information was obtained for branches, racemes, pedicels, female flowers, and seeds. Each fruit contains an embryo encased in a seed coat that is surrounded by a thin seed sac or pericarp with a persistent style, all of which is enclosed in the hypanthium. The hypanthium, which forms the fleshy portion of the fruit, contains vascular bundles, storage tissues, an endodermis, and an epidermis. The epidermis contains many trichomes and is confluent with the exterior of the pedicel. The calyx of the fruit is slightly open, and trichomes are present in the calyx opening, in the seed cavity, and on the tail of the seed sac. Harvest by removing the pedicel from the fruit rips the epidermis, which exposes fruit flesh and results in loss of juice from the fruit. Information on fruit structure is relevant to methods of harvesting.Key words: Hippophae, Elaeagnaceae, rhamnoides, mongolica Rousi, seed, microscopy.
Historical changes in the distribution and functions of large wood in Puget Lowland rivers
Authors: Collins Brian D , Montgomery David R , Haas Andrew D
Published: July 2002

We examined changes in wood abundance and functions in Puget Lowland rivers from the last ~150 years of land use by comparing field data from an 11-km-long protected reach of the Nisqually River with field data from the Snohomish and Stillaguamish rivers and with archival data from several Puget Lowland rivers. Current wood abundance is one to two orders of magnitude less than before European settlement in the Snohomish and Stillaguamish basins. Most importantly, wood jams are now rare because of a lack of very large wood that can function as key pieces and low rates of wood recruitment. These changes in wood abundance and size appear to have fundamentally changed the morphology, dynamics, and habitat abundance and characteristics of lowland rivers across scales from channel unit to valley bottom. Based on our field studies, rivers had substantially more and deeper pools historically. Archival data and field studies indicate that wood jams were integral to creating and maintaining a dynamic, anastomosing river pattern with numerous floodplain channels and abundant edge habitat and routed floodwaters and sediment onto floodplains. Establishing the condition of the riverine landscape before European settlement sets a reference against which to evaluate contemporary conditions and develop restoration objectives.
Distribution of freshwater diatoms in 64 Labrador (Canada) lakes: speciesenvironment relationships along latitudinal gradients and reconstruction models for water colour and alkalinity
Authors: Fallu Marie-Andrée , Allaire Nancie , Pienitz Reinhard
Published: July 2002

The distribution of modern diatom assemblages in surficial sediments of 64 Labrador (Canada) lakes across broad vegetational biomes was studied in order to explore speciesenvironment relationships and to develop transfer functions for paleoenvironmental reconstruction. The study sites were situated along a latitudinal gradient (51°27' to 57°37' N) and classified according to six catchment vegetation types: wetland (peatland) forest, spruce/fir forest, lichen woodland, foresttundra, coastal tundra, and tundra. Canonical correspondence analysis revealed that among 28 environmental variables determined for each site, water colour and alkalinity accounted for most of the variance in the diatom data. Using weighted-averaging partial least squares techniques, we developed transfer functions for inference of water colour (CLR) (r2jack= 0.85, root mean square error of prediction (RMSEP) = 0.18log(CLR + 1) or 1.51 Pt units) and alkalinity (ALK) (r2jack= 0.63, RMSEP = 0.25log(ALK + 1) or 1.78 µeq·L1) from the percent abundance of the 132 most abundant diatom taxa. By determining diatom distribution in relation to more detailed vegetation types within the boreal forest zone (wetland forest, spruce/fir forest, and lichen woodland), this calibration data set demonstrated the potential of these assemblages for revealing more subtle changes in lake catchment vegetation over time.
Development of STS and CAPS markers for identification of three tall larkspurs (Delphinium spp.)
Authors: Li Xiaomei , Gardner Dale R , Ralphs Michael H , Wang Richard R-C
Published: July 2002

One cleaved amplified polymorphic sequence (CAPS) and nine sequence tagged site (STS) markers were developed for identifying tall larkspur (Delphinium spp.) plants in three species based on the DNA sequence of known species-specific RAPD markers. Four STS markers were used for identification of Delphinium occidentale, three STS markers for Delphinium barbeyi, and one CAPS and two STS markers for Delphinium glaucum. One hundred sixty-six individual plants collected at 19 locations in the western U.S.A. were tested using the STS and CAPS markers. Over 95% of the D. occidentale plants contained all four D. occidentale specific STS markers, whereas the remaining plants contained three of the four STS markers. Approximately 97% of D. barbeyi plants contained all three D. barbeyi specific STS markers, and the rest had two of the three STS markers. A small percentage of D. barbeyi plants contained one D. occidentale specific STS marker. Hybrid populations were characterized as having more D. occidentale specific than D. barbeyi specific STS markers, suggesting that the three hybrid populations are composed not of F1 hybrid plants of the parental species but of segregating offspring of different generations from original hybrids. This set of STS and CAPS markers for larkspur species should be useful in classification of unknown plant materials and the identification of hybrid populations.Key words: poisonous plants, RAPD, molecular marker, PCR.
RAPD isolation of a Y chromosome specific ORF in a dioecious plant,Silenelatifolia
Authors: Nakao Shunsuke , Matsunaga Sachihiro , Sakai Atsushi , Kuroiwa Tsuneyoshi , Kawano Shigeyuki
Published: July 2002

Silene latifolia is a dioecious plant and has heteromorphic sex chromosomes: the X and Y chromosomes. The Y chromosome is the largest, and its genetic control seems to be most strict among dioecious plants. To identify the putative sex-determination elements on the Y chromosome, random amplified polymorphic DNA (RAPD) analysis was used to screen for Y chromosome specific DNA fragments, and 31 clones were successfully produced. Genomic Southern hybridization and FISH (fluorescence in situ hybridization) analyses revealed that one of the clones, #2-2, is a Y chromosome specific fragment that has a single copy on the Y chromosome. Sequence tagged site (STS)-PCR analysis also succeeded in amplifying one fragment in males and no fragments in females. Cloning and sequencing of the #2-2 flanking region using inverse PCR revealed an open reading frame (ORF) corresponding to 285 amino acids in length (ORF285), but no expression of the ORF285 gene was identified. ORF285 may be a clue to the origin of dioecy.Key words: Y chromosome, RAPD, STS, FISH, Melandrium album.
Tissue-specific expression of male-transmitted mitochondrial DNA and its implications for rates of molecular evolution inMytilusmussels (Bivalvia: Mytilidae)
Authors: Dalziel Anne C , Stewart Donald T
Published: July 2002

Mytilus and other bivalves exhibit an unusual system of mitochondrial DNA (mtDNA) transmission termed doubly uniparental inheritance (DUI). Specifically, males transmit the mtDNA they have received from their fathers to their sons. Females transmit their mother's mtDNA to both sons and daughters. Males are normally heteroplasmic and females are normally homoplasmic, but not exclusively. This system is associated with an unusual pattern of molecular evolution. Male-transmitted mtDNA (M type) evolves faster than female-transmitted (F type) mtDNA. Relatively relaxed selection on the M type has been proposed as an explanation for this phenomenon. To further evaluate the selective forces acting upon the M-type genome, we used RT-PCR to determine where it is expressed. M-type mtDNA expression was detected in all gonad samples and in 50% of somatic tissues of males, and in a single female tissue. F-type mtDNA expression was detected in all female tissues, all male somatic tissues, and all but one male gonad sample. We argue that the expression of M-type mtDNA in male somatic and male gonad tissues has implications for the strength of selection acting upon it.Key words: gender-associated mitochondrial DNA, doubly uniparental inheritance of mtDNA, Mytilus edulis, molecular evolution.
Concrete flexural members reinforced with fiber reinforced polymer: design for cracking and deformability
Authors: Newhook John , Ghali Amin , Tadros Gamil
Published: July 2002

Fiber reinforced polymer (FRP) bars have lower modulus of elasticity than steel bars. For this reason when FRP bars are used as flexural nonprestressed reinforcement in concrete sections, the stress in the FRP is limited to a relatively small fraction of its tensile strength. This limit, necessary to control width of cracks at service, governs design of the required cross-sectional area of the FRP. Parametric studies on rectangular and T-sections are presented to show that the design based on allowable strain in the FRP results in sections that exhibit large deformation before failure. The concept of deformability, given in the Canadian Highway Bridge Design Code, as a requirement in the design of sections is discussed and modifications suggested. Using the new definition, it is shown that when, in addition to the crack control requirement, an upper limit is imposed on the cross-sectional area of the FRP, no calculations will be necessary to check the deformability.Key words: fibre reinforced polymer, reinforcement, concrete, design, deformability.
Phosphorylation decreases trypsin activation and apolipoprotein AI binding to glycosylphosphatidylinositol-specific phospholipase D
Authors: Deeg Mark A , Bowen Rosario F
Published: July 2002

Glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD) is present in plasma as an apolipoprotein and as a cell-associated lipase. GPI-PLD mRNA levels are regulated, but it is unclear if posttranslational mechanisms also regulate GPI-PLD function. We examined the effect of protein kinase A phosphorylation on human serum GPI-PLD activity, trypsin activation, and apolipoprotein AI binding. Protein kinase A phosphorylation did not activate GPI-PLD activity in vitro, nor did phosphorylated GPI-PLD cleave a GPI-anchored protein from intact porcine erythrocytes. Trypsin cleaves the C-terminal β propeller of purified human serum GPI-PLD to generate three immunodetectable fragments (75, 28, and 18 kDa) in association with a 12-fold increase in enzyme activity. After phosphorylation, the amounts of 28- and 18-kDa fragments were markedly decreased with trypsin treatment, and activity was only increased five-fold. Phosphorylation also inhibits binding of GPI-PLD to apolipoprotein AI. These data are the first demonstrating that phosphorylation may regulate GPI-PLD interaction with other proteins.Key words: apolipoprotein AI, high-density lipoprotein, glycosylphosphatidylinositol, trypsin, phospholipase D.
Synthesis and reactivity of novel Schiff bases containing boronate esters
Authors: Norman David W , Edwards Janet P , Vogels Christopher M , Decken Andreas , Westcott Stephen A
Published: July 2002

Condensation of 2-aminophenol with boronate ester derivatives of benzaldehyde afforded the corresponding boron-containing Schiff bases, 2-HOC6H4N=C(H)C6H4R (1a: R = 2-Bpin; 1b: R = 3-Bpin; 1c: R = 4-Bpin; pin = 1,2-O2C2Me4). Crystals of 1b were triclinic, space group P[Formula: see text], a = 11.9420(6), b = 13.0871(7), and c = 13.2720(7) Å, α = 70.983(1), β = 67.793(1), and γ = 78.380(1)°, Z = 2. Reaction of 2-aminophenol with 2-HC(O)C6H4B(OH)2 in EtOH, however, gave a macrocyclic dimer 2 with a OBOBO structural unit. The molecular structure of this dimer has been confirmed by an X-ray diffraction study. Crystals of 2 were monoclinic, space group P21/c, a = 10.0447(8), b = 21.0894(15), and c = 12.6214(9) Å, β = 105.301(2)°, Z = 4. Further reaction of these Schiff bases with manganese triacetate in toluene afforded 2-arylbenzoxazoles 3ac via an oxidative cyclization pathway. The molecular structure of the 4-Bpin derivative (3c) was characterized by an X-ray diffraction study. Crystals of 3c were monoclinic, space group P21/n, a = 6.5392(3), b = 16.3330(8), and c = 16.1942(8) Å, β = 97.9620(10)°, Z = 4.Key words: boron heterocycles, Schiff bases, arylbenzoxazoles.
The redox properties of ferrocenyl-substituted aryl azines
Authors: Sauro Vittorio A , Workentin Mark S
Published: July 2002

A series of ferrocenyl substituted azines (1-Fc/Ar, where Ar = 4-NO2C6H4, 4-CNC6H4, 4-OCH3C6H4, C5H4N, ferrocene, anthracene, and pyrene) were investigated by electrochemical and photochemical techniques. All the 1-Fc/Ar exhibited oxidation waves within 60 mV of each other, consistent with the expected oxidation of the ferrocene moiety. The reduction properties of 1-Fc/Ar is governed by the nature of the Ar substituent. The standard reduction potentials suggest that ferrocene has comparable electron donating abilities as a 4-methoxyphenyl and 4-dimethyl aminophenyl group. The anthracenyl azines exhibit one-electron reversible reduction followed by dimerization of the radical anion resulting in dimerization rate constants (kd) between 5.1 × 104and 1.5 × 105M1s1. 1-Fc/Anth and related azines undergo photochemical E/Z isomerization of the C=N bonds to produce E/Z and Z/Z isomers from the thermodynamically most stable E/E form. Fluorescence at 77 K, was observed for these compounds only after long- wavelength irradiation to produce a mixture of E/E, E/Z, and Z/Z isomers. Fluorescence quantum yields of 0.042, 0.090, and 0.176 were determined for 2-Anth/H, 2-Anth/Anth, and 1-Fc/Anth, respectively. The electrochemical, photochemical, and X-ray data suggest that the azine unit is a conjugation "limiter" and may be a general characteristic of azine molecules.Key words: azines, electrochemistry, cyclic voltammetry, reduction, electron transfer.
Measuring and modeling surface area of ponderosa pine needles
Authors: Wykoff William R
Published: July 2002

Two methods for needle area estimation were compared for Pinus ponderosa Dougl. ex P. Laws. & C. Laws., and models were developed to predict total, projected, and abaxial areas. Areas of needles were determined by using video capture  image analysis procedures (VCIA) and by direct measurement of needle sections. VCIA area estimates were 4060% less than abaxial areas determined from direct measurements. Allometric models fit to VCIA area and mean needle width (Wv) explained 96% of the variation in measured sample areas; models omitting Wv explained 91% of the variation. Predictions for independently collected validation data were somewhat poorer and slightly biased but had similar residual patterns. Allometric models fit to midneedle width and total needle length explained 99% of the variation in directly measured needle areas, with root mean square error equal to 2% of the mean measured areas. Results were similar for the validation data. For both models, final parameters were estimated from the combined data. It is shown that fascicle areas estimated from predictions for the middle-sized needles are nearly as accurate as estimates based on measurements for entire fascicles. Direct measurement of needles is more portable than VCIA and provides more accurate needle area estimates with less measurement effort.