bluuebunny/crossref_metadata_2025_split 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

ABSTRACTThalli 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

ABSTRACTThough 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

ABSTRACTWe 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

ABSTRACTParthenogenetic 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

ABSTRACTThe 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

ABSTRACTWe 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

ABSTRACTDNA 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.
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

ABSTRACTAims 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

AimThis 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.MethodsSixteen 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).ResultsThe 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.ConclusionsThese 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

SUMMARYThere 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

SUMMARYComplete 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

SummaryUpon 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

SummaryThe 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.