bluuebunny/crossref_metadata_2025 huggingface dataset:
INDUCIBLE MECHANISMS FOR HCO3– UTILIZATION AND REPRESSION OF PHOTORESPIRATION IN PROTOPLASTS AND THALLI OF THREE SPECIES OF ULVA (CHLOROPHYTA)1
Authors: Björk Mats , Haglund Kurt , Ramazanov Ziyadin , Pedersén Marianne
Published: October 2004

Thalli of Ulva reticulata Forskaal, Ulva rigida C. Ag., and Ulva pulchra Jaasund were incubated at different concentrations of dissolved CO2. Incubation at a high CO2 concentration resulted in decreased oxygen evolution rate and lower affinity for inorganic carbon at high pH conditions, i.e. the ability to use HCO3– as a carbon source was reduced. This effect was reversible, and plants regained this HCO3– uptake capacity when transferred to air concentrations of CO2. The phytosynthetic oxygen evolution rate of plants grown at high CO2 concentration was reduced by high O2 concentrations, whereas thalli and protoplasts from cultures grown at air concentration were not affected. This is interpreted as a deactivation of the carbon‐concentrating mechanism during conditions of high CO2 resulting in high photorespiration when plants are exposed to high O2 concentrations. Protoplasts were not affected by high O2 to the same extent and were not able to utilize HCO3– from the medium. The algae were able to grow at very low CO2 concentrations, but growth was suppressed when an inhibitor of external carbonic anhydrase was present. Assay of carbonic anhydrase activities showed that external and internal CA activities were lower in plants grown at a high CO2 concentration compared to plants grown at a low concentration of CO2. Possible mechanisms for HCO3– utilization in these Ulva species are discussed.
THE BASAL APPARATUS OF THE QUADRIFLAGELLATESPERMATOZOPSIS EXSULTANS(CHLOROPHYCEAE):NUMBERING OF BASAL BODY TRIPLETS REVEALS TRIPLET INDIVIDUALITY AND DEVELOPMENTAL MODIFICATIONS1
Authors: Beech Peter L. , Melkonian Michael
Published: October 2004

Though there are no detectable structural differences between each of the axonemal doublets ofSpermatozopsis exsultansKorshikov, basal body triplets do show structural peculiarities: one triplet consistently has an electron‐dense patch appressed to its proximal part. This triplet is labeled No. 1, and all triplets are numbered in accordance to the numbering system used for other flagellate green algae. We present a detailed analysis of the basal apparatus (basal bodies and attached cytoskeletal elements) ofS. exsultansand describe how basal apparatus elements are attached, very specifically, to particular basal body triplets. The analysis includes immunogold detection of centrin‐containing structures and characterization of their sites of attachment to basal bodies. The sequence of basal body development inS. exsultansis deduced from what we know of other green algae. With this, we describe how the cytoskeletal structures associated with the separate basal bodies, particularly those attached to the right side of a basal body, undergo apparent morphological modifications from cell generation to generation. The data indicate that basal body triplets are truly different from one another and that this subsequent basal body asymmetry, combined with the developmental differences between basal bodies themselves, presumably accounts for the heterogeneity in the basal apparatus and any asymmetry in the cell as a whole.
PROTEIN BIOSYNTHESIS IN SALT‐SHOCKED CELLS OF STICHOCOCCUS BACILLARIS (CHLOROPHYCEAE)1
Authors: Ahmad Iftikhar , Hellebust Johan A.
Published: October 2004

We have developed an in vivo14C‐amino acid labelling procedure for monitoring protein synthesis in salt‐shocked cells of Stichococcus bacillaris Naeg. This alga possesses an efficient transport system for the uptake of leucine, methionine, and phenylalanine and rapidly incorporates these amino acids into proteins. Of the three amino acids tested, 14C‐phenylalanine is ideally suited for labelling proteins in S. bacillaris, as it establishes an early equilibrium between uptake and incorporation of the amino acid into proteins. The uptake of phenylalanine shows little inhibition following transfer of cells to higher salinities and is also not affected in short‐term experiments by the presence of the protein inhibitors cycloheximide and chloramphenicol. While Stichococcus bacillaris grows slowly at salinities equal to, or higher than, 150% artificial seawater (ASW), it shows surprising rates of recovery of major physiological functions following considerable salt shocks. Cells transferred from 33 to 150% ASW show complete recovery of photosynthetic activity and protein synthesis within 10–15 min, and cell transferred from 33 to 300% ASW recover 50% of their capacity to synthesize proteins within. 1 h. Cytoplasmic and organellar protein synthesis appears to be equally sensitive to the effects of salt shocks according to studies with protein synthesis inhibitors.
HAPLOID PARTHENOGENETIC SPOROPHYTES OF LAMINARIA JAPONICA (PHAEOPHYCEAE)1
Authors: Lewis Raymond J. , Jiang B. Y. , Neushul Michael , Fei X. G.
Published: October 2004

Parthenogenetic sporophytes were obtained from three strains of Laminaria japonica Areschoug. These sporophytes grew to maturity in the sea, producine spores that all grew into female gametophytes. These female gametophytes gave rise to another generation of parthenogenetic sporophytes during the next year, so that by the year 1990 parthenogenetic sporophytes had been cultivated for 12, 9, and 7 generations, respectively, for the three strains. When female gametophytes from parthenogenetic sporophytes were combined with normal male gametophytes, normal sporophytes that reproduced and gave rise to both female and male gametophytes were obtained. The parthenogenetic sporophytes were shorter and narrower than the normal sporophytes of the same strain.

Chromosome counts on mature sporophytes showed that normal sporophytes (from fertilized eggs) were diploid (2n = approximately 40) and that the spores they produced were haploid (n = approximately 20), while nuclei from both somatic and sporangial cells in parthenogenetic sporophytes were haploid. All gametophytes were haploid. Young sporophytes derived from cultures with both female and male gametophytes were diploid, while young, sporophytes obtained from female gametophytes from parthenogenetic sporophytes had haploid, diploid, or polyploidy chromosome numbers. Polyploidy was associated with abnormal cell shapes.

The presence of haploid parthenogenetic sporophytes should be use in breeding kelp strains with useful characteristics, since the sporophyte phenotype is expressed from a haploid genotype which can be more readily selected.
RESPONSE OF THE PHOTOSYNTHETIC APPARATUS OF PHAEODACTYLUM TRICORNUTUM (BACILLARIOPHYCEAE) TO NITRATE, PHOSPHATE, OR IRON STARVATION1
Authors: Geider Richard J. , La Roche Julie , Greene Richard M. , Olaizola Miguel
Published: October 2004

The effects of nitrate, phosphate, and iron starvation and resupply on photosynthetic pigments, selected photosynthetic proteins, and photosystem II (PSII) photochemistry were examined in the diatom Phaeodactylum tricornutum Bohlin (CCMP 1327). Although cell chlorophyll a (chl a) content decreased in nutrient‐starved cells, the ratios of light‐harvesting accessory pigments (chl c and fucoxanthin) to chl a were unaffected by nutrient starvation. The chl a‐specific light absorpition coefficient (a*) and the functional absorption cross‐section of PSII (σ) increased during nutrient starvation, consistent with reduction of intracellular self‐shading (i.e. a reduction of the “package effect”) as cells became chlorotic. The light‐harvesting complex proteins remained a constant proportion of total cell protein during nutrient starvation, indicating that chlorosis mirrored a general reduction in cell protein content. The ratio of the xanthophylls cycle pigments diatoxanthin and diadinoxanthin to chl a increased during nutrient starvation. These pigments are thought to play a photo‐protective role by increasing dissipation of excitation energy in the pigment bed upstream from the reaction centers. Despite the increase in diatoxanthin and diadinoxanthin, the efficiency of PSII photochemistry, as measured by the ration of variable to maximum fluorescence (Fv/Fm) of dark‐adapted cells, declined markedly under nitrate and iron starvation and moderately under phosphate starvation. Parallel to changes in Fv/Fm were decreases in abundance of the reaction center protein D1 consistent with damage of PSII reaction centers in nutrient‐starved cells. The relative abundance of the carboxylating enzyme, ribulose bisphosphate carboxylase/oxygenase (RUBISCO), decreased in response to nitrate and iron starvation but not phosphate starvation. Most marked was the decline in the abundance of the small subunit of RUBISCO in nitrate‐starved cells. The changes in pigment content and fluorescence characteristics were typically reversed within 24 h of resupply of the limiting nutrient.
PURIFICATION AND CHARACTERIZATION OF TWO FORMS OF PHOSPHOGLYCERATE KINASE FROM THE GREEN ALGA SELENASTRUM MINUTUM1
Authors: Lin Min , Turpin David H.
Published: October 2004

We report the first purification and characterization of a eukaryotic algal phosphoglycerate kinase (PGK), Two forms of PGK (PGK1 and PGK2) from the green alga Selenastrum minutum (Naeg.) Collins were purified to electrophoretic homogeneity with specific activities of 1100 and 1069 units · mg−1 protein, respectively. The portion of PGK1 and PGK2 (probably the cytosolic and chloroplastic forms, respectively) in this organism was estimated as 32 and 68%, respectively. PGK1 was more heat‐stable than PGK2. The Mr estimation for PGK1 and PGK2 by sodium dodecyl sulphate‐polyacrylamide gel electrophoresis and gel filtration indicated that they both were monomeric with a similar Mr of approximately 44 kDa. Antibodies raised against S. minutum PGK1 cross‐reacted with PGK2 as well as PGKs from prokaryotic and eukaryotic sources, suggesting that PGK1 was structurally and immunologically closely related to PGK2 and other PGKs, which was consistent with NH2‐terminal sequence analysis.

Comparative kinetic and regulatory properties of PGK1 and PGK2 from S. minutum were investigated, Both forms exhibited hyperbolic kinetics with respect to both 3‐phosphoglycerate (3‐PGA) and Mg‐adenosine triphosphate2‐ (MgATP2‐) under the conditions tested and had similar Km values for each substrate (PGK1; Km (MgATP2‐) = 0.37 mM, Km(3‐PGA) = 0.59 mM; PGK2; Km(MgATP2‐) = 0.32 mM, Km(3‐PGA) = 0.46 mM). PGK1 and PGK2, however, differed significantly in several other kinetic properties. PGK2 had a broad pH optimum between 7.3 and 7.8, as compared to PGK1, with a pH optimum of 7.3 Mg2+ was the most efficient cofactor for both forms; it inhibited PGK1 but not PGK2 at higher concentrations (>10 mM). Other divalent cations (Mn2+, Zn2+, Co2+, Cd2+, and Ca2+) only partially replaced Mg2+ and were more effective for PGK1 than for PGK2, A wide range of metabolites was examined for regulatory properties. Energy charge was the most important factor in regulating the two forms of S. minutum PGK. These results were interpreted in light of the regulation of this kinase in response to the cell energy requirement and the need for glycolytic carbon flow to provide carbon skeletons for amino acid biosynthesis.
MORPHOLOGY OF DNA CONTAINING STRUCTURES (NUCLEOIDS) AS A PROSPECTIVE CHARACTER IN CYANOPHYTE TAXONOMY1
Authors: Cepák Vladislav
Published: October 2004

DNA containing structures (nucleoids) were visualized by 4′, 6‐diamidino‐2‐phenylindole (DAPI) fluorescent staining in two groups of cyanophytes (59 filamentous oscillatorialean species and 12 coccal Synechococcus‐like organisms) to test the possibility of using nucleoid morphology in cyanophyte taxonomy. The morphology of nucleoids (size, shape, and structure) in oscillatorialean species is specific for individual families. The morphology of the nucleoid in Synechococcus‐like species agrees from the proposed separation of the genus Cyanothece from Synechococcus. A much different nucleoid morphology in three species of Cyanothece suggests that these species should be separated into a new genus. On the basis of other characters, the species could be returned to the genus Cyanobacterium. My results indicate that the morphology of nucleoids is a valuable character in the classification of the cyanophytes examined; thus, it is a prospective feature that could be used in the taxonomy of other groups of cyanophytes. Additionally, DAPI staining is not a complicated procedure. The new character is easy to see in samples taken from nature, both living and preserved.
Local rh‐VEGF administration enhances skin flap survival more than other types of rh‐VEGF administration: a clinical, morphological and immunohistochemical study
Authors: Alessandro Scalise , Maria Giovanna Tucci , Guendalina Lucarini , Federica Giantomassi , Fiorenza Orlando , Marina Pierangeli , Armanda Pugnaloni , Aldo Bertani , Giuseppe Ricotti , Graziella Biagini
Published: October 2004

Abstract:  The aim of the present study was to evaluate experimentally whether administration of recombinant (rh) vascular endothelial growth factor (VEGF) can protect skin flaps from necrosis and to study the optimum mode of rh‐VEGF administration. We used rats to study the effects of local or systemic administration of rh‐VEGF on skin flap during surgery; we also tested preoperative systemic administration of rh‐VEGF to assess whether it may prepare the tissue to respond to the hypoxic injury better than previously tested methods. The animals were 30 male Sprague‐Dawley rats. Group I rats received multiple systemic injections of rh‐VEGF in the tail artery prior to flap dissection. Group II rats were injected with rh‐VEGF in the clamped left epigastric artery during flap dissection; in this group, the left flaps thus received rh‐VEGF locally (via incubation for 10 min during hypoxia) and the right flaps systemically, after blood flow restoration. Group III received saline solution instead of VEGF in the same way as group II. Skin samples from the distal portion of the flaps were collected on day 7 for morphological and immunohistochemical analysis. The flaps exhibiting the least necrosis were those treated with local rh‐VEGF, followed by those treated with systemic rh‐VEGF. The flaps that received rh‐VEGF locally showed a strong VEGF expression on keratinocytes and endothelial cells, the greatest amount of mature and newly formed vessels and strong survivin expression in endothelial cells. Local rh‐VEGF administration should thus be considered as an effective therapeutic option to enhance the survival of a tissue at risk for perfusion.
A Switzerland of the north? TheNationalistesand a bi‐national Canada*
Authors: Kennedy James
Published: October 2004

Abstract.Nationalism is frequently associated with the break‐up of states. This article seeks to demonstrate that nationalism, through the guise ofbi‐nationalism, can be compatible with the creation and maintenance of a multinational state. The political vision of theNationalistesof Québec provides the focus. In the early twentieth century these individuals believed that Canada could emulate states such as Switzerland and Belgium, which were marked by a degree of power‐sharing. They sought the adoption of practices which have since become associated with the doctrine of ‘consociationalism’. The research suggests that these nationalists were conscious that federalism, on its own, is not sufficient to accommodate a significant national minority.
Are there gender differences in smoking cessation, with and without bupropion? Pooled‐ and meta‐analyses of clinical trials of Bupropion SR
Authors: Scharf Deborah , Shiffman Saul
Published: October 2004

Aims In this study, we examine gender differences in smoking cessation with and without treatment with Bupropion SR. We test whether women and men have comparable success rates quitting smoking regardless of treatment, whether Bupropion SR is effective for women, and whether Bupropion SR efficacy differs for men and women.

Design A literature search was conducted to identify relevant trials. Data were analyzed with individual‐level (pooled) and study‐level (meta‐analytical) statistics.

Participants Data from 4421 participants in 12 randomized smoking cessation trials of Bupropion SR 300 mg versus placebo were analyzed.

Findings Results from the meta‐analysis revealed that Bupropion SR was an effective aid to smoking cessation [odds ratio (OR) = 2.49, 95% confidence interval (CI) = 2.06–3.00]. Moreover, Bupropion SR proved to be an effective cessation aid for women (OR = 2.47, 95% CI = 1.92–3.17). No treatment–gender interaction was observed; women and men benefited equally from treatment with Bupropion SR (Q = 0.01, NS). Overall, women were less successful at quitting than men, regardless of treatment (OR = 0.79, 95% CI = 0.65–0.95). These results were replicated with pooled, individual‐level analyses.

Conclusions Bupropion SR is an effective smoking cessation aid for women. In these trials, women have less success quitting smoking than men, whether treated with Bupropion SR or placebo. There is a need to understand more about why women are less able to quit.
Concurrent administration of donepezil HCl and risperidone in patients with schizophrenia: assessment of pharmacokinetic changes and safety following multiple oral doses
Authors: Reyes Josephine F. , Preskorn Sheldon H. , Khan Ahsan , Kumar Dinesh , Cullen Edward I. , Perdomo Carlos A. , Pratt Raymond D.
Published: October 2004

Aim

This open‐label, multiple‐dose trial investigated the effect of concurrent administration of donepezil HCl with risperidone on the pharmacokinetics (PK) and safety profiles of both drugs.

Methods

Sixteen male patients with schizophrenia, who were receiving stable, physician‐optimized risperidone (1–4 mg twice daily), and 15 healthy age‐ and weight‐matched male controls, received donepezil HCl 5 mg daily for 7 days. Patients with schizophrenia remained on their physician‐optimized dose of risperidone throughout the study. Pharmacokinetic parameters (Cmax, tmax and AUC) were assessed from plasma drug concentrations measured in blood collected before, during and after administration (for 12 h after risperidone on days 0 and 7, and for 24 h after donepezil HCl on day 7).

Results

The mean age of all the subjects was 38.5 years. Donepezil PK parameters were similar between patients taking donepezil HCl + risperidone (AUC0−24 h = 329.0 ± 17.2 ng·h ml−1) and controls taking donepezil HCl alone (AUC0−24 h = 354.7 ± 28.2 ng·h ml−1). Pharmacokinetic parameters for risperidone and 9‐OH risperidone were not altered in patients with schizophrenia after 7 days of donepezil HCl administration (AUC0−12 h standardized by dose: risperidone = 59.6 ± 16.3 ng·h ml−1 at day 0, 56.0 ± 15.8 ng·h ml−1 at day 7; 9‐OH risperidone = 162.1 ± 19.2 ng·h ml−1 at day 0, 163.3 ± 15.0 ng·h ml−1 at day 7). The most common adverse event in both treatment groups was diarrhoea (6/16 risperidone + donepezil HCl patients and 9/16 donepezil HCl only subjects). There were no significant changes in physical examination, ECG, vital signs or treatment‐emergent abnormal laboratory values associated with either of the treatment regimens. No subject developed extrapyramidal side‐effects following donepezil administration.

Conclusions

These results suggest that once‐daily dosing of 5 mg donepezil HCl does not alter the PK of risperidone in patients with schizophrenia. The combination of risperidone and donepezil HCl was well tolerated.
Chemical induction of HO-1 suppresses lupus nephritis by reducing localiNOS expression and synthesis of anti-dsDNA antibody
Authors: TAKEDA Y , TAKENO M , IWASAKI M , KOBAYASHI H , KIRINO Y , UEDA A , NAGAHAMA K , AOKI I , ISHIGATSUBO Y
Published: October 2004

There is accumulating evidence that haem oxygenase (HO)-1 plays a protective role in various disorders. The beneficial efficacy of HO-1 induction therapy has been shown in renal diseases such as glomerulonephritis, interstitial nephritis and drug induced nephrotoxicity. However, involvement of HO-1 in the development of autoimmune renal diseases remains uncertain. To assess the clinical efficacy of HO-1 induction therapy for lupus glomerulonephritis, MRL/lpr mice were intraperitoneally injected with 100 µmol/kg hemin, a potent HO-1 inducer, or PBS as controls, once a week from 6 weeks of age to 21–24 weeks-old. We found that treatment with hemin led to a significant reduction of proteinuria and remarkable amelioration of glomerular lesions accompanied by decreased immune depositions. In addition, the circulating IgG anti-double-stranded DNA antibody level was significantly decreased in hemin treated mice when compared with controls. A single intraperitoneal injection with hemin resulted in reduction of inducible nitric oxide synthase expression in the kidney and spleen, and serum interferon-γ level. Our results suggest that HO-1 induction therapy ameliorates lupus nephritis by suppressing nitric oxide (NO) dependent inflammatory responses and attenuating production of pathogenic autoantibodies.
No evidence for apoptosis of decidual leucocytes in normal and molar pregnancy: implications for immune privilege
Authors: PONGCHAROEN S , BULMER J N , SEARLE R F
Published: October 2004

Complete hydatidiform moles are totally paternally derived and represent complete allografts that might be expected to provoke maternal immune rejection. Our previous and other studies have shown expression of Fas by increased numbers of activated decidual CD4+ T cells in both complete and partial molar pregnancy as well as increased FasL+ expression by molar trophoblasts compared with trophoblasts in normal pregnancies. As the Fas/FasL system represents a major apoptotic pathway that can play a role in immune privilege, the aim of this study was to investigate whether apoptosis of decidual immune cells, particularly T cells, could be responsible for maternal immune tolerance in molar pregnancy. Using terminal deoxynucleotidyl transferase (TdT)-mediated nick end-labelling (TUNEL), a significant increase in TUNEL+ cells was demonstrated in decidua associated with partial (P = 0·0052) and complete (P = 0·0096) hydatidiform mole compared with normal early pregnancy. Co-labelling immunoperoxidase studies showed that the TUNEL+ cells in both normal and molar pregnancies were not activated CD45RO+ immune cells, CD3+ T cells, CD56+ uterine natural killer (NK) cells or CD14+ CD68+ macrophages. Double immunohistochemical labelling with antiactive caspase-3 and leucocyte markers confirmed the lack of leucocyte apoptosis. Double immunostaining with anticytokeratin to detect trophoblast and M30 CytoDeath, which detects a neoepitope of cytokeratin 18 revealed after caspase-mediated cleavage, revealed apoptotic extravillous trophoblast cells within decidual tissue. We conclude that there is no evidence that apoptosis of decidual leucocytes plays a role in maintaining maternal tolerance in either normal or molar pregnancy.
Disparate ability of murine CD8α− and CD8α+ dendritic cell subsets to traverse endothelium is not determined by differential CD11b expression
Authors: Colvin Bridget L. , Lau Audrey H. , Schell Amanda M. , Thomson Angus W.
Published: October 2004

Upon Ag uptake and response to maturation stimuli, dendritic cells (DC) are directed through lymphatic or blood vessel endothelium to T cell areas of secondary lymphoid tissues by the constitutively expressed CC chemokines CCL19 and CCL21. We have shown that mature (m) murine CD8α+ DC exhibit poorer migratory ability to these chemokines than classic CD8α– DC by quantifying their in vitro chemotaxis through unmodified Transwell® filters. We hypothesized that lower surface expression (compared to CD8α– mDC) of the adhesion molecule CD11b on CD8α+ DC might limit their ability to adhere to filter pores in vitro and/or endothelium in vitro/in vivo. To test the role of this and/or other adhesion molecules (CD11a, CD31, CD54 and CD62L) in regulating murine DC subset migration, we used specific mAbs to block their function and quantified their migration through resting or tumour necrosis factor (TNF)‐α‐activated endothelial cell (EC) layered‐Transwell® filters. Both CD8α+ and CD8α– subsets migrated through resting EC (albeit less than in the absence of EC) in response to CCL19 and CCL21, and migration through TNF‐α‐activated EC was enhanced. In contrast to reports concerning human DC, transendothelial migration of the murine DC subsets was not dependent on CD11b, CD31, or CD62L expression by these cells. CD54 and CD11a, however, were at least partly involved in DC/EC interactions. This is the first report to examine adhesion molecules involved in transendothelial migration of murine DC subsets.
Age‐dependent variation in the proportion and number of intestinal lymphocyte subsets, especially natural killer T cells, double‐positive CD4+ CD8+ cells and B220+ T cells, in mice
Authors: Ishimoto Yuiko , Tomiyama‐Miyaji Chikako , Watanabe Hisami , Yokoyama Hisashi , Ebe Kazuto , Tsubata Shunsuke , Aoyagi Yutaka , Abo TORU
Published: October 2004

The age‐dependent variation in the proportion and number of lymphocyte subsets was examined at various extrathymic sites, including the liver, small intestine, colon and appendix in mice. In comparison with young mice (4 weeks of age), the number of total lymphocytes yielded by all tested organs was greater in adult (9 weeks) and old (40 weeks) mice. The major lymphocyte subset that expanded with age was interleukin‐2 receptor (IL‐2R) β+ CD3int cells (50% of them expressed NK1.1) in the liver, whereas it was CD3+ IL‐2Rβ– NK1.1– cells at all intraepithelial sites in the intestine. Although NK1.1+ CD3+ cells were present at intraepithelial sites in the intestine, the proportion of this subset was rather low. The ratio of CD4 to CD8 tended to decrease among natural killer T (NKT) cells and T cells at all intraepithelial sites in the intestine with age. A unique population of double‐positive CD4+ CD8+ cells in the small intestine increased in old mice. B220+ T cells were found mainly in the appendix and colon, and the proportion of these T cells decreased in old mice. Conventional NKT cells were very few in Jα281–/– and CD1d–/– mice in the liver, while NKT cells which existed in the appendix remained unchanged even in these mice. This was because unconventional CD8+ NKT cells were present in the intestine. The present results suggest that despite the fact that both the liver and intraepithelial sites in the intestine carry many extrathymic T cells, the distribution of lymphocyte subsets and their age‐associated variation are site‐specific.
Dendritic cells and follicular dendritic cells express a novel ligand for CD38 which influences their maturation and antibody responses
Authors: Wykes Michelle N. , Beattie Lynette , Macpherson Gordon G. , Hart Derek N.
Published: October 2004

CD38 is a cell surface molecule with ADP‐ribosyl cyclase activity, which is predominantly expressed on lymphoid and myeloid cells. CD38 has a significant role in B‐cell function as some anti‐CD38 antibodies can deliver potent growth and differentiation signals, but the ligand that delivers this signal in mice is unknown. We used a chimeric protein of mouse CD38 and human immunogobulin G (IgG) (CD38‐Ig) to identify a novel ligand for murine CD38 (CD38L) on networks of follicular dendritic cells (FDCs) as well as dendritic cells (DCs) in the spleen. Flow‐cytometry found that all DC subsets expressed cytoplasmic CD38L but only fresh ex vivo CD11c+ CD11b– DCs had cell surface CD38L. Anti‐CD38 antibody blocked the binding of CD38‐Ig to CD38L, confirming the specificity of detection. CD38‐Ig immuno‐precipitated ligands of 66 and 130 kDa. Functional studies found that CD38‐Ig along with anti‐CD40 and anti‐major histocompatibility complex (MHC) class II antibody provided maturation signals to DCs in vitro. When CD38‐Ig was administered in vivo with antigen, IgG2a responses were significantly reduced, suggesting that B and T cells expressing CD38 may modulate the isotype of antibodies produced through interaction with CD38L on DCs. CD38‐Ig also expanded FDC networks when administered in vivo. In conclusion, this study has identified a novel ligand for CD38 which has a role in functional interactions between lymphocytes and DCs or FDCs.
Pathogenesis of collagen‐induced arthritis: modulation of disease by arthritogenic T‐cell epitope location
Authors: Tang Bo , Brand David D. , Ma Zhijun , Stuart John M. , Myers Linda K. , Kang Andrew H.
Published: October 2004

Collagen‐induced arthritis (CIA) is an animal model of human rheumatoid arthritis that can be induced in susceptible mice by immunization with type II collagen (CII) or with collagen fragments, including cyanogen bromide (CB) peptides. One susceptible mouse strain, B10.RIII (I‐Ar), has previously been found to respond to two major T‐cell determinants, namely CII 610–618 (GPAGTAGAR) within CB10 and CII 445–453 (GPAGPAGER) within CB8. Although CB10 contains the immunodominant determinant, it is not arthritogenic. Using recombinant techniques, the determinant within CB10 was mutated to rCB10T614P,A617E, generating a recombinant CB10 that in effect contained the arthritogenic epitope. When used for immunization, rCB10T614P,A617E was arthritogenic. This suggested that the arthritogenic property was intrinsic to the epitope and unrelated to its position within the CII molecule. To test this hypothesis, additional mutants were generated. The wild‐type T‐cell epitope of CB10 was deleted from its natural position, and the ‘arthritogenic’ GPAGPAGER T‐cell epitope was inserted into the C‐terminal portion of the CB10 peptide. The resulting peptide induced arthritis in B10.RIII mice. Adding a second copy of the T‐cell determinant to other sites within CB10, however, had varying results. A second T‐cell epitope located at the C‐terminus of rCB10 significantly increased the incidence and severity of arthritis, while determinants placed in other positions had little effect. These data indicate that the T‐cell epitope has intrinsic arthritogenic properties, but there are positional and structural constraints that affect its arthritogenicity. Enhanced arthritis was associated with an increased T‐cell proliferation to the peptides, an increase in the level of inflammatory cytokines, and higher levels of anti‐CII immunoglobulin. These data suggest that the position and copy number of T‐cell determinants also affect the overall immune T‐cell responses.
The uses of photography in clinical nursing practice and research: a literature review
Authors: Riley Robin G. , Manias Elizabeth
Published: October 2004

Aims. The aim of this paper is to report a study to identify themes and provide a ‘snap‐shot’ of the scope and uses of photography in clinical nursing practice and research.

Background. Despite the dominance of vision as a way of understanding the world in Western societies, the applications of photography in clinical nursing practice and research have not been well synthesized or reported in the literature.

Methods. A computerized search of CINAHL database was performed using the terms photographs, photography, photographic, photovoice, videorecording and videotaping. Hand searching for additional citations was also undertaken.

Findings. The identified papers on photography were categorized into broad themes that reflected the different applications to which photography had been applied: documentation and surveillance; therapeutic intervention; teaching, learning and evaluating performance; research methods; and descriptive and instructional literature. Approaches to the use of photography, as recorded in the nursing literature, are broad and include: wound surveillance, covert patient surveillance, photo essay, art therapy, self‐portraits, life albums, simulated recall, participant observation, photovoice, photo hermeneutics, production of research scenarios, and video modelling.

Conclusions. The most common applications of photography in nursing and related journals include photo elicitation to promote understanding in research, videorecording as a method of teaching and learning, and as a method of observation, with more creative approaches tending to be employed in health professions other than nursing. Few reports gave explanations of how researchers negotiated ethical concerns when seeking approval for studies in clinical settings, and few gave details of the processes of data analysis.
Aspects of pharmacodynamics and biotransformation of the glucocorticoid resocortol butyrate
Authors: Coert A. , Verheijen F. , Horspool L. J. I. , Mol J. A.
Published: October 2004

Aspects of the biotransformation and pharmacodynamics of the novel glucocorticoid resocortol butyrate (RCB) and its metabolites were assessed in vitro and in vivo in comparison with selected reference compounds. The main route of biotransformation of (3H)‐RCB in the skin and the liver was 5α‐reduction of the A‐ring followed by reduction of the 3‐carbonyl group. In the liver, metabolism was much more rapid than in the skin and 5β‐reduction also occurred. RCB had a relative binding affinity for the glucocorticoid receptor similar to that of triamcinolone acetonide, about 1.5 times that of dexamethasone, three times that of betamethasone valerate (BMV) and 10–14 times that of cortisol. The metabolites of RCB displayed only low to very low affinities for the receptor. The suppression of the hypothalamic‐pituitary‐adrenal axis was investigated in placebo‐ and positive‐controlled studies in dogs by measurement of basal and corticotrophin‐releasing hormone (CRH) stimulated plasma cortisol concentrations. The AUC of the plasma cortisol vs. time curve following CRH stimulation, a measure of adrenal suppression, was reduced significantly after topical application of BMV compared with the pretreatment values. The AUC in the RCB group was not reduced significantly. Adrenocorticotrophic hormone concentrations were not affected. Oral administration of RCB did not suppress adrenocortical function, whereas BMV induced almost complete suppression of basal and CRH‐induced cortisol concentrations. The pharmacodynamics of RCB makes it a relatively safe glucocorticosteroid for topical application.
Binding of HCV E2 to CD81 induces RANTES secretion and internalization of CC chemokine receptor 5
Authors: Nattermann J. , Nischalke H. D. , Feldmann G. , Ahlenstiel G. , Sauerbruch T. , Spengler U.
Published: October 2004

Summary.  Hepatitis C virus (HCV) infection has been shown to be associated with reduced expression of the CC chemokine receptor (CCR) 5, and reduced responsiveness of lymphocytes to chemokines. However, the mechanism by which HCV alters CCR5 expression remains unclear. Here, we investigated whether altered CCR5 expression in hepatitis C results from interactions of CD81 with the HCV E2 protein. Peripheral blood mononuclear cells (PBMC) from HCV‐negative individuals were prepared by Ficoll density gradient separation. PBMC subpopulations (CD4+, CD8+ lymphocytes, CD19+ B cells, natural killer (NK) cells and monocyte‐derived dendritic cells) were isolated and stimulated with immobilized HCV E2, and changes in CCR5 expression and CC‐chemokine secretion were determined. Migration assays were performed using a 5‐μm nitrocellulose filter microchamber system according to the manufacturer's recommendations. Exposure of PBMC to HCV E2 induced a dose‐dependent release of regulated on activation normal T‐cell‐expressed and secreted (RANTES), down‐regulation of CCR5 expression and intracellular accumulation of CCR5. This effect was blocked by preincubation of PBMC with anti‐CD81. RANTES release following exposure to HCV E2 was mainly attributable to CD8+ cells. After exposure to HCV E2 markedly fewer CD8‐positive lymphocytes were attracted by RANTES when compared with CD8+ cells that were studied in the absence of HCV E2. Our results suggest that interaction of HCV E2 with CD81 leads to increased RANTES secretion by CD8+ lymphocytes which induces down‐regulation of CCR5 surface via receptor internalization resulting in altered lymphocyte migration.
Control of virulence gene expression by plant calcium in the phytopathogen Erwinia carotovora
Authors: Flego Diana , Pirhonen Minna , Saarilahti Hannu , Palva Tuula K. , Palva E. Tapio
Published: October 2004

Plant calcium can modulate a particular plant–pathogen interaction and have a decisive role in disease development. Enhanced resistance to the phytopathogenic enterobacterium Erwinia carotovora, the causal agent of bacterial soft rot disease, is observed in high‐calcium plants. One of the main virulence determinants of E. carotovora, the PehA endopolygalacturonase, is specifically required in the early stages of the infection. Production of PehA was found to be dependent on the calcium concentration in the bacterial environment. An increase in extracellular calcium to mM concentrations repressed pehA gene expression without reducing or even enhancing expression of other extracellular enzyme‐encoding genes of this pathogen. An increase in plant calcium levels could be correlated to enhanced resistance to E. carotovora infection and to an inhibition of in planta production of PehA. Ectopic expression of pehA from a calcium‐insensitive promoter allowed E. carotovora to overcome this calcium‐induced resistance. The results imply that plant calcium can constitute an important signal molecule in plant–pathogen interaction, which acts by modulating the expression of virulence genes of the pathogen.
Assembly of the cell division protein FtsZ into ladder‐like structures in the aerial hyphae of Streptomyces coelicolor
Authors: Schwedock J. , McCormick J. R. , Angert E. R. , Nodwell J. R. , Losick R.
Published: October 2004

In the filamentous bacterium Streptomyces coelicolor, the cell division protein FtsZ is required for the conversion of multinucleoidal aerial hyphae into chains of uninucleoidal spores, although it is not essential for viability. Using immunofluorescence microscopy, we have shown that FtsZ assembles into long, regularly spaced, ladder‐like arrays in developing aerial hyphae, with an average spacing of about 1.3 μm. Within individual hyphae, ladder formation was relatively synchronous and extended for distances over 100 μm. These ladders were present only transiently, decreasing in intensity as chromosomes separated into distinct nucleoids and disappearing upon the completion of septum formation. Evidence from the overall intensity of immunofluorescence staining suggested that ladder formation was regulated in part at the level of the accumulation and degradation of FtsZ within individual aerial hyphae. Finally, FtsZ ladder formation was under developmental control in that long arrays of FtsZ rings could not be detected in certain so‐called white mutants (whiG, whiH and whiB), which are blocked in spore formation. The assembly of FtsZ into ladders represents the earliest known molecular manifestation of the process of spore formation, and its discovery provides insight into the role of whi genes in the conversion of aerial hyphae into chains of spores. We have also described a novel use of a cell wall‐staining technique to visualize apical tip growth in vegetatively growing hyphae.
Localized reversible frameshift mutation in an adhesin gene confers a phase‐variable adherence phenotype in mycoplasma
Authors: Zhang Qijing , Wise Kim S.
Published: October 2004

The variable adherence‐associated (Vaa) antigen of Mycoplasma hominis is an abundant surface lipoprotein adhesin that may mediate important interactions of this wall‐less prokaryotic pathogen with the human host. Extensive mutational variation of Vaa size, as well as sequence and antigenic divergence, has been described previously. Using a series of clonal isolates representing an isogenic lineage of variants oscillating in Vaa expression, Vaa is further shown in this study to undergo high‐frequency phase variation in expression, which correlated precisely with the ability of M. hominis to adhere to cultured human cells. Although no DNA rearrangements or sequence differences in the 5′ regions flanking vaa alleles were detected between Vaa+ and Vaa− variants, intragenic vaa sequences from this lineage revealed an oscillating mutation involving a single nucleotide deletion/insertion in a short tract of adenine residues near the 5′ end of the mature Vaa coding sequence, which created a translational frameshift resulting in either a complete Vaa ORF or an in‐frame UAG stop codon immediately downstream of the poly‐A tract. Evidence for the occurrence of this high‐frequency frameshift mutation in vivo was obtained from analysis of PCR‐generated vaa sequences amplified from the joint synovial fluid of a patient with M. hominis‐associated arthritis, which indicated that Vaa phase variation occurs during M. hominis infection in the natural host. These results identify a distinctive frameshift mutator element in the vaa gene that governs M. hominis adherence and highlight the importance of mutational alteration of primary gene products on the mycoplasma surface as a means of generating and maintaining functional diversity in the host.
The Pai‐associated leuX specific tRNALeu5 affects type 1 fimbriation in pathogenic Escherichia coli by control of FimB recombinase expression
Authors: Ritter Angelika , Gally David L. , Olsen Peter B. , Dobrindt Ulrich , Friedrich Arne , Klemm Per , Hacker Jörg
Published: October 2004

The uropathogenic Escherichia coli strain 536 (O6:K15: H31) carries two large chromosomal pathogenicity islands (Pais). Both Pais are flanked by tRNA genes. Spontaneous deletion of Pai II results in truncation of the leuX tRNALeu5 gene. This tRNA is required for the expression of type 1 fimbriae (Fim) and other virulence factors. Transcription of fimA, encoding the major type 1 fimbrial subunit is controlled by an invertable DNA switch. The inversion is catalysed by two recombinases, FimB and FimE. FimB is able to turn the switch on, FimE only off. The fimB gene of strain 536 contains five TTG codons recognized by tRNALeu5, fimE contains only two. It was proposed that turning on the fim switch requires efficient translation of FimB, in turn requiring tRNALeu5. Strains in which the TTG codons in fimB were replaced with CTG codons at the wild‐type locus were able to produce type 1 fimbriae in the absence of leuX. fimB transcription was influenced by the presence of leuX, but only slightly affected by the presence or absence of leuX codons in fimB. FimB translation was significantly higher from codon‐replaced fimB genes than that of wild‐type fimB genes in various strain backgrounds. The fim switch was shown to be switched off in leuX − derivatives of E. coli 536, but could be found in the on position when the codon‐altered fimB gene was exchanged into the chromosome of these strains. From these data, it is apparent that tRNALeu5 is required for efficient translation of FimB, in turn, leading to type 1 fimbrial expression.
Neuronal correlates of gastric pain induced by fundus distension: a 3T‐fMRI study
Authors: Lu C.‐L. , Wu Y.‐T. , Yeh T.‐C. , Chen L.‐F. , Chang F.‐Y. , Lee S.‐D. , Ho L.‐T. , Hsieh J.‐C.
Published: October 2004

Visceral hypersensitivity in gastric fundus is a possible pathogenesis for functional dyspepsia. The cortical representation of gastric fundus is still unclear. Growing evidence shows that the insula, but not the primary or secondary somatosensory region (SI or SII), may be the cortical target for visceral pain. Animal studies have also demonstrated that amygdala plays an important role in processing visceral pain. We used fMRI to study central projection of stomach pain from fundus balloon distension. We also tested the hypothesis that there will be neither S1 nor S2 activation, but amygdala activation with the fundus distension. A 3T‐fMRI was performed on 10 healthy subjects during baseline, fullness (12.7 ± 0.6 mmHg) and moderate gastric pain (17.0 ± 0.8 mmHg). fMRI signal was modelled by convolving the predetermined psychophysical response. Statistical comparisons were performed between conditions on a group level. Gastric pain activated a wide range of cortical and subcortical structures, including thalamus and insula, anterior and posterior cingulate cortices, basal ganglia, caudate nuclei, amygdala, brain stem, cerebellum and prefrontal cortex (P < 0.001). A subset of these neuronal substrates was engaged in the central processing of fullness sensation. SI and SII were not activated during the fundus stimulation. In conclusion, the constellation of neuronal structures activated by fundus distension overlaps the pain matrices induced musculocutaneous pain, with the exception of the absence of SI or SII activation. This may account for the vague nature of visceral sensation/pain. Our data also confirms that the insula and amygdala may act as the central role in visceral sensation/pain, as well as in the proposed sensory‐limbic model of learning and memory of pain.
Diagnosis of flea allergy dermatitis: comparison of intradermal testing with flea allergens and a FcɛRI α‐based IgE assay in response to flea control
Authors: LAFFORT‐DASSOT CATHERINE , CARLOTTI DIDIER‐NOËL , PIN DIDIER , JASMIN PIERRE
Published: October 2004

Abstract  The objective of this study was to evaluate the accuracy ofin vivoandin vitrotests in the diagnosis of flea allergy dermatitis in comparison with history, clinical signs and response to flea control. Intradermal testing using four different sources of flea allergens and FcɛRIα‐based immunoglobulin (Ig)E assays were performed in 15 flea‐allergic dogs, 15 atopic dogs and 15 dogs infested with fleas but showing no clinical signs of skin disease. Sensitivity, specificity, negative predictive value, positive predictive value and accuracy were calculated for all five tests and results varied greatly. Sensitivity, specificity and overall accuracy were 27, 83 and 64%, respectively, for one extract (Isotec), 67, 90 and 82% for another extract (Greer), 93, 90 and 91% for flea saliva, 40, 90 and 73% for the recombinant Cte f 1 both produced by Heska Corp. and 87, 53 and 64% for a FcɛRIα‐based IgE assay. These results indicate that intradermal testing with flea extracts is more accurate in the diagnosis of flea allergy dermatitis thanin vitrotests. Moreover, pure flea saliva used as a reagent for intradermal testing provided the best results in terms of sensitivity, specificity and overall accuracy although the Greer extract, a whole body flea extract, also allowed a good correlation between intradermal testing results and clinical approach to flea allergy dermatitis diagnosis.
Three new DRB alleles routinely identified by sequence‐based typing: DRB1*010103, DRB1*0326 and DRB3*0219
Authors: Dubois V. , Favre‐Victoire I. , Gebuhrer L.
Published: October 2004

Abstract:  We describe here two additional DRB1 alleles found in two Caucasoid recipient candidates for organ transplant and a new DRB3 allele found in a Caucasoid unrelated bone marrow donor from the German file. HLA‐DRB generic and allele typing were performed using commercial kits, subsequently exon 2 was sequenced. We found a DRB1*010101 with a silent mutation at codon 68 and a DRB1*0306 with a mutation at codon 38 (T‐C) which causes an amino acid substitution from Val to Ala. DRB3*0219 differs from DRB3*020201 by two‐point mutations at codons 60 and 74 (A/C and A/G, respectively). These mutations at positions 266 and 308 were responsible for two amino acid substitutions (Tyr to Ser and Gln to Arg).