bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transfer of Phosphatidylethanol Between Lipoproteins
Authors: Liisanantti Marja K. , Huhta Kimmo , Savolainen Markku J. 
Published: November 2004

Background: Phosphatidylethanol (PEth) is an abnormal phospholipid formed only in the presence of ethanol. It has been recently shown that lipoprotein‐associated PEth may mediate the effects of ethanol on endothelial cells, and this may explain, at least in part, the beneficial effect of ethanol on atherosclerosis. This study was performed to investigate the transfer of PEth between lipoproteins and the effects of PEth on cholesteryl ester transfer protein (CETP) activity in plasma.Methods: Lipoproteins were isolated from the plasma of healthy male volunteers (n= 16) and male alcoholics (n= 13). The transfer of cholesteryl esters and PEth was determined between labeled low‐density lipoprotein (LDL) and unlabeled high‐density lipoprotein particles in vitro. The electrophoretic mobility of PEth‐modified LDL particles was determined by agarose gel electrophoresis.Results: PEth was transferred from PEth‐modified LDL to high‐density lipoprotein at an initial rate of 25.9 nmol/ml/hr. Monoclonal antibody (TP2) against the putative lipid‐binding domain of CETP inhibited the transfer rate of PEth by approximately 64%, whereas the cholesteryl ester transfer was inhibited by 86%. This indicates that most of PEth was transferred by transfer proteins other than CETP.Conclusions: The transfer of PEth between lipoproteins enables the redistribution of PEth from lipoprotein fractions with a slow turnover to those with a rapid clearance. Moreover, the PEth‐induced change in the electrical charge of lipoproteins may affect the binding of lipoproteins to their receptors and binding proteins. This in turn may alter the metabolism of lipoproteins and lipid‐mediated signaling pathways in the cells delineating the vascular wall.
Blockade of the Leptin‐Sensitive Pathway Markedly Reduces Alcohol Consumption in Mice
Authors: Blednov Yuri A. , Walker Danielle , Harris R Adron 
Published: November 2004

Background: The neuropeptide leptin links adipose stores with hypothalamic centers and serves as an endocrine signal involved in the regulation of appetite (and possibly in the endorphinergic modulation of the drug reward system). Increased plasma leptin has been observed at the onset of alcohol withdrawal in humans, and ethanol consumption after withdrawal was increased by injection of leptin in mice. We addressed the role of leptin in alcohol‐related behaviors by studying ethanol consumption in two strains of spontaneously mutant mice that lack leptin (ob/ob) or the leptin receptor (db/db).Methods: Two strains of mutant leptin‐deficient (ob/ob) or leptin‐resistant (db/db) mice were tested in a two‐bottle‐choice paradigm and were compared with wild‐type (C57BL/6 inbred strain) mice. The effects of leptin injection on voluntary ethanol intake have been investigated in ob/ob and C57BL/6 mice.Results: Males and females of both mutant strains showed a significantly lower preference for alcohol in a two‐bottle‐choice paradigm compared with wild‐type mice. Male ob/ob mice demonstrated slightly higher avoidance of bitter taste, and females of the both mutant strains showed a reduced preference for saccharin solutions. Administration of leptin (1 mg/kg intraperitoneally, daily for 8 days) altered body weight but failed to increase the preference for ethanol in ob/ob mice; i.e., we could not correct the effects of leptin deficiency on alcohol consumption by the injection of leptin. Also, there were no differences between the effects of leptin (1 mg/kg intraperitoneally, daily for 8 days) and saline injections on alcohol consumption in C57BL/6 mice.Conclusions: These data show that blockade of the leptin pathway markedly decreases the preference for alcohol intake, but this decrease may be the result of compensatory or developmental changes in other systems rather than a more direct effect of leptin on alcohol consumption.
Prostacyclin, thromboxane A2 and the effect of low‐dose ASA in pregnancies at high risk for hypertensive disorders
Authors: Vainio Merja , Riutta Asko , Koivisto Anna‐Maija , Mäenpää Johanna 
Published: November 2004

Background.  The aim of this study was to investigate the prostanoid production in pregnancies at high risk for hypertensive disorders, and the effect of low‐dose acetylsalicylic acid (ASA) on prostanoids.Material and methods.  Ninety women with a bilateral notching in uterine arteries screened by Doppler ultrasound at 12–14 gestational weeks were randomized to the ASA (0.5 mg/kg/day) or placebo group. Forty‐three women in both groups were followed up throughout the pregnancy. Urine samples were taken at baseline, and at 24–26 and 32–34 weeks of gestation to determine the urinary 11‐dehydrothromboxane B2 (u‐11‐dehydro‐TxB2) and 2,3‐dinor‐6‐keto‐prostaglandin F1α (u‐2,3‐dinor‐6‐keto‐PGF1α), the metabolites of thromboxane A2 and prostacyclin, respectively.Results.  In the pregnancies with pregnancy‐induced hypertension (PIH) before 37 gestational weeks, the 2,3‐dinor‐6‐keto‐PGF1α/11‐dehydro‐TxB2 ratio did not increase as much as in other pregnancies (P = 0.028). In the placebo group pregnancies with preeclampsia had significantly lower 2,3‐dinor‐6‐keto‐PGF1α (P = 0.019) at 12–14 weeks of gestation compared to other pregnancies. In the placebo group the 2,3‐dinor‐6‐keto‐PGF1α/11‐dehydroTxB2 ratio remained unchanged throughout the pregnancy, with no significant difference between pregnancies with a normal or an adverse outcome. In the ASA group the 2,3‐dinor‐6‐keto‐PGF1α/11‐dehydro‐TxB2 ratio increased (P < 0.001, early vs. midpregnancy). Again, the changes were similar in pregnancies with a normal or an adverse outcome.Conclusion.  The balance of prostacyclin and thromboxane A2 shifted in an unfavorable direction in pregnancies complicated by PIH. ASA had a favorable effect on the prostanoids.
Pregnancy outcomes in unselected singleton pregnant women with an increased risk of first‐trimester Down's syndrome
Authors: Liu Silvia So‐Aei , Lee Fa‐Kung , Lee Jia‐Ling , Tsai Ming‐Song , Cheong Mei‐Leng , She Bo‐Quing , Chen Su‐Chee 
Published: November 2004

Background.  The purpose of this study was to assess outcomes in pregnancies with a positive screen of first‐trimester combined test (nuchal translucency, pregnancy‐associated plasma protein‐A and free beta‐human chorionic gonadotropin).Methods.  Using a cut‐off level of 1 in 270, 216 (7.1%) women had a positive screen. Among them, 187 delivered their babies in our hospital and the adverse outcomes, such as spontaneous abortion, intrauterine fetal demize, preterm prelabor rupture of the membranes, preterm labor, intrauterine growth restriction, gestational hypertensive disorders, placenta previa, chromosomal abnormalities and fetal structural anomalies, were identified and compared with the 2097 women who screened negative for Down's syndrome.Results.  Pregnancies with a positive screen had a significantly higher risk of adverse outcomes than those with negative screens (30.5% versus 15.3%; odds ratio 2.4; p < 0.001), especially for those complicated by spontaneous abortion (odds ratio 11.4; p < 0.05) and placenta previa (odds ratio 4.3; p < 0.05).Conclusions.  Besides fetal chromosomal abnormalities and structural abnormalities, pregnancies with a positive screen for Down's syndrome in the first‐trimester had a significantly higher incidence of subsequent adverse obstetric outcomes.
Young women with genital prolapse have a low collagen concentration
Authors: Söderberg Marie Westergren , Falconer Christian , Byström Birgitta , Malmström Anders , Ekman Gunvor 
Published: November 2004

Background.  Genital prolapse is a common and handicapping form of pelvic floor dysfunction. To explain its genesis as a result of endopelvic connective tissue weakness, the collagen state was analyzed in women with and without genital prolapse.Methods.  Punch biopsies from the paraurethral ligaments were obtained during the operation from 22 women undergoing surgery for genital prolapse. As controls, similar biopsies were taken from 13 women who underwent gynecologic surgery for other benign reasons. Collagen concentration as hydroxyproline and its extractability by pepsin digestion were studied in relation to age by multiple regression, two‐way anova, Levene's test, and Student's t‐test. Histological examination was also performed.Results.  Women, younger than 53 years, with genital prolapse had a 30% lower collagen concentration than age‐matched controls, which reached significance, P = 0.01. The extractability by pepsin digestion, an indicator of cross‐links in the collagen molecule, did not significantly differ between groups. It did, however, decrease significantly with age in both prolapse patient and control groups. Morphology supported these findings with a less‐dense extracellular matrix composition subepithelially in genital prolapse compared to a healthy control.Conclusion.  For the first time, we show that young women with genital prolapse have a decreased collagen concentration, suggesting a different organization of the endopelvic connective tissue extracellular matrix. Furthermore, these alterations differ from those earlier found in younger women with stress urinary incontinence.
Subsequent pregnancy outcome after conservative treatment of a previous cesarean scar pregnancy
Authors: Seow Kok‐Min , Hwang Jiann‐Loung , Tsai Yieh‐Loong , Huang Lee‐Wen , Lin Yu‐Hung , Hsieh Bin‐Chwen 
Published: November 2004

Background.  To assess pregnancy course and outcome after conservative treatment of a cesarean scar pregnancy.Methods.  During an 8‐year period, 15 cases of cesarean scar pregnancies were diagnosed at our institution. Seven of the 14 patients for whom we successfully preserved the uterus became pregnant within 3 years after termination of the scar pregnancy. The year of diagnosis, conservative method and gestational age for these five patients were recorded. Delivery method, time interval between the scar pregnancy and subsequent pregnancy, and maternal and neonatal outcome were evaluated.Results.  Seven pregnancies (eight live and one dead baby) were noted. The mean interval between the ectopic pregnancy and subsequent pregnancy was 13.3 months (range 0–34 months). One patient, who became pregnant 3 months after the scar pregnancy was found, suffered uterine rupture at 38.3 weeks' gestational age. Two patients with placental accrete, and one of them who continued the existing intrauterine twin pregnancy after transvaginal sono‐guided aspiration of the scar pregnancy received a cesarean hysterectomy at 32 weeks of gestation. The remaining four pregnancies were uneventful, followed by early cesarean sections at 36 weeks.Conclusion.  The results of this first series of seven subsequent pregnancies after conservative treatment of scar pregnancies are promising. An early cesarean section before over‐extension of the uterus and spontaneous labor can help to prevent uterine rupture. Placenta accrete is another severe morbidity of these patients in addition to uterine rupture. Thus a cesarean hysterectomy may be the choice of treatment.
Low plasma levels of oxidized low density lipoprotein in preeclampsia
Authors: Raijmakers Maarten T. M. , Van Tits Berry J. H. , Hak‐Lemmers Heidi L. M. , Roes Eva Maria , Steegers Eric A. P. , Peters Wilbert H. M. 
Published: November 2004

Background.  Markers of lipid peroxidation are commonly used to assess oxidative stress in preeclampsia. The aim of this study was to assess the concentration of oxidized low density lipoprotein (oxLDL), a novel marker for lipid peroxidation, and that of the thiobarbituric acid reactive substances (TBARS) in the pathogenesis of severe preeclampsia and to investigate the influence of gestational age on these parameters.Method.  Plasma levels of oxLDL and TBARS were assayed in women with severe preeclampsia (n = 40), normotensive pregnant controls matched for gestational age (n = 24) and normotensive pregnant controls at full term (n = 16).Results.  Women with preeclampsia showed lower oxLDL levels (mean ± SE) than matched controls (181 ± 12 vs. 219 ± 14; p = 0.027), whereas no differences were found for the TBARS concentration (3.8 ± 0.6 vs. 3.7 ± 0.4). When women with preeclampsia were compared to control women at full term, TBARS were elevated (3.8 ± 0.6 vs. 1.5 ± 0.2; p = 0.01). However, in women with normotensive pregnancy TBARS were also lower in full‐term control pregnancy compared to early third‐trimester values (p < 0.0001).Conclusion.  Plasma TBARS decreased during the third trimester of pregnancy, underlining the importance of matching for gestational age when studying markers of lipid peroxidation in pregnant women. Women with preeclampsia had lower plasma levels of oxLDL compared to gestational age‐matched controls, indicating that oxLDL could be a marker for preeclampsia.
EFFECTS OF SELECTED PHYSICOCHEMICAL FACTORS ON GROWTH AND ZOOSPOROGENESIS OF CLADOPHORA GLOMERATA (CHLOROPHYTA)1
Authors: Hoffmann James P. , Graham Linda E. 
Published: November 2004

ABSTRACTThe effects of vitamin B1 and B12, temperature, light intensity and photoperiod on dry weight production and zoosporogenesis of Cladophora glomerata (L.)Kütz. were investigated by factorial experiments. Statistical analysis showed all of the above factors to be significantly (P < 0.01) influenced by these two parameters. Zoosporogenesis appeared to be more sensitive to vitamin limitation than dry weight production. Dry weight production and zoosporogenesis exhibited significantly different maxima. Dry weight production was most strongly influenced by temperature whereas photoperiod exerted the strongest influence on zoosporogenesis. It was possible to experimentally separate the light intensity and photoperiod factors; analysis showed photoperiod to be the primary factor influencing zoosporogenesis. Among the conditions tested, an 8:16 h LD short day photoperiod elicited the greatest number of zoosporangia.
OCTOSPORIELLA COLORADOENSIS GEN. ET SP. NOV., A NEW TETRASPORALEAN GREEN ALGA FROM TWO COLORADO MOUNTAIN LAKES1
Authors: Kugrens Paul 
Published: November 2004

ABSTRACTA new green alga, Octosporiella coloradoensis, belonging to the order Tetrasporales, family Tetrasporaceae, is described from Colorado mountain lakes. Colonies are planktonic or attached, the latter often forming loosely aggregated colonial complexes, thus creating an irregularly shaped complex. Individual colonies are spherical and consist of eight subcolonies, with each subcolony having spherically arranged octads of cells. Each vegetative cell bears two pseudoflagella that extend well beyond the colonial sheaths. Cell division is by eleutheroschisis and may be synchronous or asynchronous. Daughter colony formation is apparently coenobic, with each cell in the octad forming new subcolonies of eight cells each. Zoospore formation may precede daughter colony formation but the flagella remain rigid and non‐motile. Large akinetes form in response to nutrient depletion. These germinate to produce eight aplanospores which divide to reconstitute a typical colony of Octosporiella. Sexual reproduction was not observed.
THE MAJOR HISTONE‐LIKE PROTEIN FROM THE NONPHOTOSYNTHETIC DINOFLAGELLATE CRYPTHECODINIUM COHNII (PYRROPHYTA) IS PRESENT IN STATIONARY PHASE CULTURES1
Authors: Rizzo Peter J. , Choi J. , Morris R. L. 
Published: November 2004

ABSTRACTAn improved method is described for the isolation of nuclei from the nonphotosynthetic dinoflagellate Crypthecodinium cohnii (Seligo) Chatton in Grassé. The new method results in an increase in yield from about 13% to 45% or higher, with no loss in purity or activity of endogenous RNA polymerase. Most of this increase in yield is from the ability of 25% Ficoll to cause many cells to shed their walls, and from the stabilizing effect of hexylene glycol during cell disruption. The histone‐like protein, previously undetectable in chromatin from stationary phase cells, can now be demonstrated in chromatin from stationary as well as log phase cells. Preliminary experiments indicate that this protein inhibits transcription.
THE ECOLOGY OF EPIPELIC ALGAE OF FIVE WELSH LAKES, WITH SPECIAL REFERENCE TO VOLVOCALEAN GREEN FLAGELLATES (CHLOROPHYCEAE)1
Authors: Happey‐Wood Christine M. , Priddle Julian 
Published: November 2004

ABSTRACTThe ecology of epipelic algae on the marginal sediments of five Welsh lakes was studied over an annual cycle. The lakes, Llydaw, Cwellyn, Padarn, Maelog and Coron ranged from very oligotrophic to nutrient‐rich. Attention was focussed on chlamydomonad flagellates, diatoms, blue‐green algae and euglenoids and the different proportions of these in algae in the epipelon of lakes of contrasting water quality.A total of 75 algal taxa was found in the five lakes, 25 were species of volvocalean flagellates. Mean annual population density of these flagellates differed by an order of magnitude between the lakes. The greatest population density was recorded forChlamydomonas anticontataSchiller in nutrient‐rich Llyn Maelog. Twenty species of pennate diatoms were recorded frequently in the epipelon. In the nutrient‐rich lakes, Maelog and Coron, pennate diatoms were dominant on the sediments, where they exhibited population maxima in spring and autumn. Increase in numbers of epipelic diatoms was recorded when silica concentrations were minimum in the overlying lake waters.Navicula hungaricaGrun. achieved the maximum population density, 260 000 cells · cm−2. Euglenoids formed large epipelic populations during late‐summer and autumn in these nutrient‐rich lakes. Blue‐green algae were more important, proportionally, in the nutrient‐poor mountain lakes, which had sediments of higher organic content. Chlamydomonads were the major algal component of the epipelon in the mountain lakes, Llydaw and Cwellyn, where the sediments were characterized by larger particle size, and higher organic content. In the nutrient‐rich lakes, where the sediments had higher calcium content, chlamydomonads formed significant populations only during spring and summer, when nutrient levels were minimal in the overlying lakewaters.
SILICON UPTAKE BY ALGAE WITH NO KNOWN Si REQUIREMENT. I. TRUE CELLULAR UPTAKE AND pH‐INDUCED PRECIPITATION BY PHAEODACTYLUM TRICORNUTUM (BACILLARIOPHYCEAE) AND PLATYMONAS SP. (PRASINOPHYCEAE)1
Authors: Nelson David M. , Riedel Gerhardt F. , Millan‐Nunez Roberto , Lara‐Lara J. Ruben 
Published: November 2004

ABSTRACT Phaeodactylum tricornutum Bohlin, the one diatom known to lack a silicon requirement for growth, and the prasinophyte Platymonas sp. are two representatives of a taxonomically diverse group of planktonic algae that have been reported to take up Si without a demonstrable requirement for the element. For both species, removal of Si from solution during growth in batch culture has at least two components; true biological uptake throughout the growth of the culture, and spontaneous inorganic precipitation of a solid silicate phase–probably Mg2Si3O8 (sepiolite)–under the elevated pH conditions that prevail late in batch growth. It is not clear to what extent previous observations of Si uptake by algae without siliceous frustules may be influenced by inorganic, non‐cellular precipitation. The kinetics of true cellular uptake of Si are similar in Phaeodalylum and Platymonas, and different from those reported for the Si‐requiring diatoms. Uptake follows hyperbolic saturation kinetics in both species, with half‐saturation concentrations of 97.4 μM in Phaeodactylum and 80.9 μM in Platymonas, as compared to ca. 1–6 μM in diatoms that form siliceous frustules. Uptake by Phaeodactylum and Platymonas is not substrate‐saturated until the dissolved Si concentration of the medium exceeds 200 μM. Concentrations this high do not occur in the surface layer of the ocean, and the kinetics suggest that both species deposit much less silica in nature than they can be induced to deposit in culture.
ULTRASTRUCTURE OFCHAETOCEROS MUELLERI(BACILLARIOPHYCEAE): AUXOSPORE, RESTING SPORE AND VEGETATIVE CELL MORPHOLOGY1
Authors: Reinke Danny C. 
Published: November 2004

ABSTRACTThe structure of the frustule of auxospores, resting spores and vegetative cells ofChaetoceros muelleriLemm. are described with LM and SEM. Vegetative frustules are relatively small and lightly silicified, are not united into filaments, and appear unornamented under LM and SEM. The setae are circular to subcircular in transverse section with spines and puncta arranged in a spiral pattern. The resting spore and auxospore frustules are more silicified than the vegetative frustules and appear unornamented under LM and SEM. The auxospores of C.muelleriwere previously unknown.
INFLUENCE OF GROWTH STATUS AND NUTRIENTS ON EXTRACELLULAR POLYSACCHARIDE SYNTHESIS BY THE SOIL ALGACHLAMYDOMONAS MEXICANA(CHLOROPHYCEAE)1
Authors: Kroen William K. , Rayburn William R. 
Published: November 2004

ABSTRACTIncreased levels of nitrogen in liquid growth medium bring about increased growth and a delay in extracellular polysaccharide production byChlamydomonas mexicanaLewin on a per‐cell basis. Addition of nitrogen to stationary phase cultures causes renewed growth and a temporary lag in polysaccharide synthesis until growth again ceases. Removal of nitrogen terminates growth, causing an immediate increase in polysaccharide synthesis. Phosphate‐starved cells show a response similar to nitrogen‐starved cells, indicating that the beginning of stationary phase and not nitrogen depletion causes the stimulation in extracellular polysaccharide synthesis. As similar results are assumed to occur on soil, the significance of this response is discussed.
THE MORPHOLOGY AND DEVELOPMENT OF SOME PROMINENTLY STALKED SOUTHERN AUSTRALIAN HALYMENIACEAE (CRYPTONEMIALES, RHODOPHYTA). II. THE SPONGE‐ASSOCIATED GENERA THAMNOCLONIUM KUETZING AND CODIOPHYLLUM GRAY1
Authors: Scott Fiona J. , Wetherbee Richard , Kraft Gerald T. 
Published: November 2004

ABSTRACTThree members of the red algal family Halymeniaceae (Thamnoclonium dichotomum (J. Ag.) J. Ag., Codiophyllum flabelliforme (Sond.) Schmitz, and C. decipiens (J. Ag.) Schmitz) are investigated. All are endemic to southern and southwestern Australia, possess basal stalks of substantial size and firmness, and are consistently associated with specific sponge taxa. In each case, the sponges are bonded by collagen‐like fibrils to the host cuticle without modifying the algal tissue at the ultrastructural level. Secondary cortication and prominent growth rings occur in the stalks of all three species, and in each the pit plugs between cells become wider, more convoluted and less electron dense with increasing distance from the surface. Such pit plugs are apparently a unique attribute of the stalked Halymeniaceae. The three species share pit plug, sponge association and stalk morphological features but are not otherwise closely related, as they actually represent three distinct genera.