bluuebunny/crossref_metadata_2025_split huggingface dataset:
NEUTRAL LIPIDS AS MAJOR STORAGE PRODUCTS IN ZOOSPORES OF THE GIANT KELP MACROCYSTIS PYRIFERA (PHAEOPHYCEAE)1
Authors: Brzezinski Mark A. , Reed Daniel C. , Amsler Charles D. 
Published: August 2006

ABSTRACTNeutral lipids, consisting primarily of triacylglycerols, were found to be a major form of carbon reserve in zoospores of the giant kelp Macrocystis pyrifera (L.) C. Ag. The fluorescent stain Nile Red revealed large lipid droplets in the posterior end of the cell, which comprised 20–41% of cellular carbon in newly released spores. Flow cytometric analyses of newly released spores stained with Nile Red revealed considerable variation in the neutral lipid content among spores that was independent of spore size. Lipid droplets were consumed during germination in spores maintained either under constant light or in continual darkness. The availability of light appeared to delay, but did not preclude, lipid use. The rate of lipid use during germination varied considerably among germlings with some cells consuming all of their lipid reserves within 5 h after release. In addition to zoospores, lipid droplets were observed in both male and female gametes. Numerous droplets were observed in eggs, while single lipid droplets were observed in sperm. Neutral lipid droplets were not observed in gametophytes or sporophytes except in developing gametes and spores. Large lipid reserves thus seem to be confined to the microscopic life history stages that presumably have relatively high energy demands. By serving as a supplemental fuel reserve, neutral lipids may be important in extending the effective range of zoospore dispersal.
MICROALGAL LIGHT‐HARVESTING IN EXTREME LOW‐LIGHT ENVIRONMENTS IN MCMURDO SOUND, ANTARCTICA1
Authors: Robinson Dale H. , Arrigo Kevin R. , Iturriaga Rodolfo , Sullivan Cornelius W. 
Published: August 2006

ABSTRACT Microalgal pigment composition, photosynthetic characteristics, single‐cell absorption efficiency (Qa(λ)) spectra, and fluorescence‐excitation (FE) spectra were determined for platelet ice and benthic communities underlying fast ice in McMurdo Sound, Antarctica, during austral spring 1988. Measurements of spectral irradiance (E(λ)) and photosynthetically active radiation (PAR) as well as samples for particulate absorption measurements were taken directly under the congelation ice, within the platelet layer, as profiles vertically through the water column, and at the benihic surface. Light attenuation by.sea ice, algal pigments, and particulates reduced PAR reaching the platelet ice layer to 3%(9–33 fimol photons m‐2‐−s‐1) of surface values and narrowed its spectral distribution to a band between 400 and 580 nm. Attenuation by the water column further reduced PAR reaching the sea floor (28–m depth) to 0.05% of surface levels (< 1 μmol photons m‐2 s‐1), with a spectral distribution dominated by 470–580–nm wavelengths. The photoadaptive index (I) for platelet ice algae (5.9–12.6 μmol photons m‐2.s‐1) was similar to ambient PAR, indicating that algae had acclimated to their light environment (i.e. the algae were light‐replete). Maximum Qa(λ) at the blue absorption peak (440 nm) was 0.63, and enhanced absorption was observed from 460–500 nm and was consistent with observed high cellular chlorophyll (chi) c:chl a and fucoxanthin: chl a molar ratios (0.4 and 1.2, respectively). Benthic algae were light‐limited despite the maintenance of very low Ik values (4–11 μmol photons.m‐2.s‐1). Extremely high fucoxanthin: chi a ratios (1.6) in benthic algae produced enhanced green light absorption, resulting in a high degree of complementation between algal absorption and ambient spectral irradiance. Qa(λ) values for benthic algae were maximal (0.9) between 400 and 510 nm but remained >0.35 even at absorption minima. Strong spectral flattening, a characteristic of intense pigment packaging, was also apparent in the Qa(λ) spectra for benthic algae. FE and Qa(λ) spectra were similar in shape for platelet ice algae, indicating that the efficiency at which absorbed energy was transferred to photosystem II (PSII) was independent of wavelength. Fluorescence emission by benthic algae was greatest for the 500–560–nm excitation wavelengths, suggesting that most energy absorbed by accessory pigments was transferred to PSII. These results suggest that under ice algae employ complementary pigmentation and maximize absorption efficiency as adaptive strategies to low‐light stress. Regulating the distribution of absorbed energy between PSI and PSII may be an adaptive response to the restricted spectral distribution of irradiance.
EXTRACELLULAR PEROXIDASE‐MEDIATED OXYGEN CONSUMPTION IN CHLAMYDOMONAS REINHARDTII (CHLOROPHYTA)1
Authors: Torkelson Joel D. , Lynnes Jaret A. , Weger Harold G. 
Published: August 2006

ABSTRACT The unicellular green alga Chlamydomonas reinhardtii Dang. displays a high capacity for salicylhydroxamic acid (SHAM)—stimulated O2 consumption, mediated by extracellular peroxidaie. Addition of exogenous NADH also resulted in stimulation of O2 consumption. The SHAM‐and NADH‐stimulated peroxidase activity was partially sensitive to inhibition by exogenous superoxide dismutase, ascorbate, and gentisic acid. These compounds did not inhibit O2 consumption in the absence of effectors. SHAM‐and NADH‐stimulated peroxidase activity also was sensitive to inhibition by cyanide, and cyanide titration curves indicated that O2 consumption by peroxidase was more cyanide‐sensitive than O2 consumption by cytochrome oxidase. The differential sensitivity to cyanide was used to estimate partitioning of O2 consumption between mitochondrial respiration and extracellular peroxidase. We suggest that, despite a large capacity for peroxidase‐me‐diated O2 consumption, peroxidase did not consume O2 at detectable rates in the absence of effectors. Therefore, in the absence of effectors, measured rates of O2 consumption represented the rate of mitochondrial respiration.
LOROXANTHIN, A PHYLOGENETICALLY USEFUL CHARACTER IN CHLAMYDOMONAS AND OTHER CHLOROPHYCEAN FLAGELLATES1
Authors: Fawley Marvin W. , Buchheim Mark A. 
Published: August 2006

ABSTRACT The distribution of loroxanthin in chlorophycean flagellates is consistent with their phylogeny as inferred from molecular and organismal characters. Although polarity of this character cannot yet be determined, if the absence of loroxanthin is plesiomorphic for chlorophycean flagellates, the presence of loroxanthin defines a clade that includes the Euchlamydomonas morphological group, two other species of Chlamydomonas, C. asymmetrica and C. oblonga, and Gonium pectorale. A subsequent reversal to loroxanthin absence is apomorphic for the more complex volvocacean taxa. These results suggest that loroxanthin distribution will be useful for resolving phylogenetic questions in green algae.
Hog1 Mitogen-Activated Protein Kinase Plays Conserved and Distinct Roles in the Osmotolerant Yeast
Torulaspora delbrueckii
Authors: Hernandez-Lopez María José , Randez-Gil Francisca , Prieto José Antonio 
Published: August 2006

ABSTRACT

Torulaspora delbrueckii
has emerged during evolution as one of the most osmotolerant yeasts. However, the molecular mechanisms underlying this unusual stress resistance are poorly understood. In this study, we have characterized the functional role of the high-osmolarity glycerol (HOG) mitogen-activated protein kinase pathway in mediating the osmotic stress response, among others, in
T. delbrueckii
. We show that the
T. delbrueckii
Hog1p homologue TdHog1p is phosphorylated after cell transfer to NaCl- or sorbitol-containing medium. However, TdHog1p plays a minor role in tolerance to conditions of moderate osmotic stress, a trait related mainly with the osmotic balance. In consonance with this, the absence of TdHog1p produced only a weak defect in the timing of the osmostress-induced glycerol and
GPD1
mRNA overaccumulation. Td
hog1
Δ mutants also failed to display aberrant morphology changes in response to osmotic stress. Furthermore, our data indicate that the
T. delbrueckii
HOG pathway has evolved to respond to specific environmental conditions and to play a pivotal role in the stress cross-protection mechanism.
Soleus muscle force following downhill running in ovariectomized rats treated with estrogen
Authors: Sotiriadou Sofia , Kyparos Antonios , Albani Maria , Arsos Georgios , Clarke Mark S.F. , Sidiras Georgios , Angelopoulou Nikoletta , Matziari Chrysoula 
Published: August 2006

The ovariectomized (OVX) rat model was used to investigate the effects of estrogen treatment on soleus muscle functionality in situ following muscle injury induced by downhill running. Fifty immature, 24- to 26-d-old, OVX rats were randomly assigned to 5 separate experimental groups: sedentary controls (OVX-Sed), placebo-treated and studied immediately after exercise (OVX-Pb0), placebo-treated and studied 72 h after exercise (OVX-Pb72), estradiol-treated and studied immediately after exercise (OVX-Ed0), and estradiol-treated and studied 72 h after exercise (OVX-Ed72). At the age of 9 weeks, under ketamine and xylazine anesthesia i.p., the rats were subcutaneously implanted with either placebo or 17β-estradiol-impregnated pellets (0.05 mg/pellet, 3 week release). Treatment with 17β-estradiol increased the estradiol plasma levels in OVX animals to those normally seen during the proestrous cycle of normal animals. Three weeks after the implantation the rats were subjected to a 90 min intermittent downhill running protocol. Our results indicate that the exercise protocol used in the study induced injury in the soleus muscle, as it was detected by the significant reduction in unfused (stimulation at 10, 20, and 40 Hz) and maximal (Po) tetanic force, as well as the decreased ability of the soleus muscle to maintain tension (stimulation at 40 Hz for 3 min) in OVX-Pb0 and OVX-Pb72 placebo-treated animals subjected to downhill running (injured muscles) as compared with OVX-Sed control rats (uninjured muscle). Estradiol replacement in OVX rats partially protected the soleus muscle from the injury normally induced by downhill running. As compared with the OVX-Pb0 and OVX-Pb72 placebo-treated groups, the soleus muscles of OVX-Ed0 and OVX-Ed72 estradiol-treated rats were capable of producing significantly greater unfused tetanic force and had an increased ability to maintain tension after fatigue. However, estrogen at the dose administered did not prevent the decrease in maximal tetanic force. We postulate that the protective effect of estrogens on muscle strength may be related to the ability of estrogen hormones to attenuate the E–C coupling failure and (or) the disorganization of the contractile apparatus associated with eccentric exercise through a mechanism or mechanisms yet to be fully understood.
Determination of aerobic work and power on a rope-braked cycle ergometer by direct measurement
Authors: Gordon Rae S. , Franklin Kathryn L. , Baker Julien S. , Davies Bruce 
Published: August 2006

The purpose of this study was to compare the power and work outputs of a cycle ergometer using the manufacturer’s guidelines, with calculations using direct flywheel velocity and brake torque. A further aim was to compare the values obtained with those supplied by the manufacturer. A group of 10 male participants were asked to pedal a Monark 824E ergometer at a constant cadence of 60 r/min for a period of 3 min against a resistive mass of 3 kg. The flywheel velocity was measured using a tachometer. The brake force was determined by measuring the tension in the rope on either side of the flywheel. The calculated mean power was 147.45 ± 6.5 W compared with the Monark value of 183 ± 3.7 W. The difference between the methods for power estimation was 18% and was statistically significant (p < 0.01). The mean work done by the participants during the 3 min period was found to be 26 460 ± 1145 J compared with the Monark value of 33 067 ± 648 J (p < 0.01). The Monark formulae currently used to determine the power and work done by a participant overestimates the actual values required to overcome the resistance. There findings have far-reaching implications in the physiological assessment of athletic, sedentary, and diseased populations.
Effect of cold acclimation on neuromuscular function of the hand
Authors: Geurts Carla L.M. 
Published: August 2006

The research in this thesis investigated the effects of cold stress on neuromuscular function with the main focus on cold acclimation. In total, 6 studies, 1 field study and 5 experiments, were conducted. The field study showed that during manual work in cold weather, finger and hand temperature can drop to levels that may impair manual function. The first 2 experiments were conducted to investigate the effect of acute local cold stress on force control and to investigate the effect of cold-induced vasodilatation (CIVD) on neuromuscular function. In experiment 1, it was found that cooling of the hand in 10 °C cold water for 10 min did not improve force control, although neuromuscular function was significantly impaired after cooling. In experiment 2, cold-induced vasodilatation, occurring after 20 min of 8 °C cold-water immersion of the hand, was confined to the finger tip and had no effect on the temperature of the first dorsal interosseus (FDI) muscle or its neuromuscular function. A series of cold acclimation studies was conducted to investigate the effect of repeated cold-water hand immersions on neuromuscular function. In these experiments, neuromuscular function was tested before and after 2–3 weeks of daily hand immersion in 8 °C cold water for 30 min. In experiment 3, it was found that 3 weeks of cold-water immersion resulted in a decrease in minimum and mean index finger temperature and CIVD was attenuated. Neuromuscular function was not affected by this change in temperature response. In experiment 4, one hand was exposed daily to cold water and compared with the opposite control hand. Blood plasma catecholamine concentrations were increased after 2 weeks in the cold-exposed hand, but no changes in temperature response or neuromuscular function were found after repeated cold exposure. Thermal comfort after 30 min of cold-water immersion significantly improved after repeated cold exposure causing a discrepancy between actual and perceived temperature and it was suggested that this may impose a greater risk of cold injury owing to a change in behavioural thermoregulation. In the last experiment, core temperature was elevated by bicycling at a submaximal level during the cold hand immersion. Exercise had a direct effect on the temperature response during cold-water immersion, decreasing the minimum FDI temperature and slowing down the deteriorating effect of cold on neuromuscular function; however, exercise showed was no effect on local cold acclimation. It is concluded that local repeated cold exposures may improve finger and hand temperature and subjective thermal ratings, but that these changes are too small to improve neuromuscular function. The best remedy to maintain manual function is to limit or avoid cold stress as much as possible. If sufficient protection of the hands is impossible, core heating through exercise or passive heating may be a solution.
Airway distensibility in normal and asthmatic subjects and partitioning of the Fowler dead space
Authors: Johns David P. , Burns Graham , Reid David W. , Walls Justin , Maskrey Michael , Walters E. Haydn 
Published: August 2006

Anatomical dead space measured by the Fowler method (VDF) is the sum of 2 serial volume compartments (VDF = VDp1 + VDp2). VDF has been shown to increase linearly with end-inspiratory lung volume (EILV) and the gradient of the relationship (ΔVDF) has been used as an index of airway distensibility. The aim of this study was to partition VDF into its serial compartments VDp1 and VDp2 to test the hypothesis that, given the greater distensibility of distal airways, VDp2 would demonstrate greater volume dependence than VDp1. The relationships between each measure of VD (VDF, VDp1, and VDp2) and EILV were studied in 16 healthy subjects and 16 mildly asthmatic subjects. Significant (p < 0.05) linear relationships were obtained between each measure of VD and EILV in both subject groups. Changes in VDp1 with EILV (ΔVDp1) accounted for 78.6% ± 5.6% (mean ± SEM) and 72.6% ± 6.3% of ΔVDF in the healthy and asthmatic groups, respectively. ΔVDp1 was greater in the healthy subjects than in asthmatic subjects (18.4 versus 13.1 mL/L, p = 0.005). We conclude that in both asthmatic and healthy subjects, the major component of ΔVDF was ΔVDp1 and not ΔVDp2, as originally hypothesized. We believe our results are reflecting the degree of asynchronous airway emptying.
Effects of ingesting a high-fat diet upon exercise-training cessation on fat accretion in the liver and adipose tissue of rats
Authors: Yasari Siham , Paquette Amélie , Charbonneau Alexandre , Gauthier Marie-Soleil , Savard Roland , Lavoie Jean-Marc 
Published: August 2006

The purpose of the present study was to determine if exercise trained rats might benefit from protection against fat accumulation in response to an obesity stimulus initiated upon training cessation. Two groups of female rats were either treadmill trained for 8 weeks (DTr) or remained sedentary (Sed). They were then submitted either to a high-fat diet (HF; 42 E%) or kept on a standard diet (SD; 12.5 E% lipids) for another 6 weeks while remaining sedentary. Fat accumulation in liver and adipocytes along with fat-cell diameter and plasma free fatty acid (FFA) levels were measured 0, 2, and 6 weeks after training cessation. Immediately after the training period (t = 0), DTr rats exhibited similar body mass and higher dietary intake but smaller body fat content (4 fat pads) compared with Sed rats. DTr rats, under both diets, exhibited higher gains in body fat than Sed rats (DTr vs. Sed, 71% vs. 8% and 132% vs. 55% for SD and HF, respectively), such that fat mass in all 4 depots was similar to Sed rats 6 weeks after training cessation. Despite higher adipocyte fat accretion, liver lipid infiltration was not increased in DTr animals and plasma FFA levels were lower throughout the detraining period. In addition, plasma leptin levels remained lower in DTr animals throughout the detraining period under the HF diet condition. The present results indicate that previously exercise trained rats are not protected against adipocyte fat accumulation whether they ingest a standard or a high-fat diet.
Effect of Human Leukocyte Antigen Class I Expression of Tumor Cells on Outcome of Intravesical Instillation of Bacillus Calmette-Guerin Immunotherapy for Bladder Cancer
Authors: Kitamura Hiroshi , Torigoe Toshihiko , Honma Ichiya , Sato Eiji , Asanuma Hiroko , Hirohashi Yoshihiko , Sato Noriyuki , Tsukamoto Taiji 
Published: August 2006

Abstract
Purpose: Various immune systems play important roles in the clinical efficacy of intravesical Bacillus Calmette-Guerin (BCG) instillation for bladder cancer. However, human leukocyte antigen (HLA) class I molecules on tumor cells and various immune system cells infiltrating to/around the tumor have not been evaluated, although many prognostic factors, including clinical, pathologic, and molecular ones, have been investigated. The aim of this study was to determine immunologic prognostic factors of BCG immunotherapy for bladder cancer.
Experimental Design: Immunohistochemical staining for HLA class I, CD4, CD8, CD20, CD68, TIA-1, S-100, and FOXP3 was carried out on specimens from 30 patients who underwent BCG immunotherapy from whom both pretreatment and posttreatment specimens were obtained. We did univariate and multivariate analyses of factors affecting recurrence-free survival. The positive, weakly positive, and negative groups of cells that infiltrated to/around the tumor were compared with recurrence-free survival using the Kaplan-Meier method and log-rank test.
Results: HLA class I was a significant prognostic factor both in univariate and multivariate analyses. The 5-year recurrence-free survivals of the patients with HLA class I–positive tumors and those with HLA class I–negative tumors were 55.7% and 19.1%, respectively (P = 0.019). There was a significant association between infiltration of CD8, CD20, and CD68-positive cells after BCG therapy and therapeutic effects.
Conclusions: Our data show that expression of HLA class I molecules on tumor cells contributes significantly to the therapeutic effect of BCG immunotherapy for bladder cancer. It is suggested that CTLs may be one of main effectors in this therapy.
The Prognostic Value of Circulating Tumor Cells in Patients with Melanoma: A Systematic Review and Meta-analysis
Authors: Mocellin Simone , Hoon Dave , Ambrosi Alessandro , Nitti Donato , Rossi Carlo Riccardo 
Published: August 2006

Abstract
Background: The detection of circulating tumor cells (CTC) in patients with melanoma represents an appealing prognostic tool, but no consensus exists on this topic. We aimed to comprehensively and quantitatively summarize the evidence for the use of CTC to predict patients' clinical outcome.
Methods: Fifty-three studies enrolling 5,433 patients were reviewed. Correlation of CTC status with tumor-node-metastasis disease stage and patients' overall (OS) and progression-free (PFS) survival was assessed by means of association statistics and meta-analysis, respectively.
Results: CTC status correlated with both tumor-node-metastasis stage (stage I, 32%; stage II, 41.7%; stage III, 41.1%; stage IV, 47.4%; Ptrend &lt; 0.0001) and survival (OS: hazard ratio, 2.42; 95% confidence interval, 1.7-3.45, P &lt; 0.0001; PFS: hazard ratio, 2.45; 95% confidence interval, 1.78-3.38; P &lt; 0.0001). However, statistical heterogeneity was significant for both OS and PFS, likely underscoring the wide variability in study design. Furthermore, CTC positivity rates in early stages were higher and in the metastatic setting were lower than expected, which indicates an unsatisfactory accuracy of currently available CTC detection assays.
Conclusions: Our findings suggest that CTC might have a clinically valuable prognostic power in patients with melanoma. However, the heterogeneity of the studies thus far published warrants caution not to overestimate the favorable results of pooled data.
c-Rel plays a key role in deficient activation of B cells from a non–X-linked hyper-IgM patient
Authors: Lu Kristina T. , Sinquett Frank L. , Dryer Rebecca L. , Song Charles , Covey Lori R. 
Published: August 2006

AbstractOur previous results demonstrated that B cells from a patient (pt1) with non–X-linked hyper-IgM syndrome (HIGM) possess an atypical CD23lo phenotype that is unaffected by CD40-mediated activation. To investigate the molecular mechanism underlying defective CD23 expression in pt1 B cells, we used lymphoblastoid cell lines that express LMP1 under the control of a tetracycline-inducible promoter (LCLtet). Our analysis revealed that the CD23lo phenotype in the pt1-LCLtet cells is a direct consequence of diminished CD23 transcription. We demonstrate a marked decrease in c-Rel–containing complexes that bind to the proximal CD23a/b promoters in pt1-LCLtet extracts, resulting from an overall lower expression of c-Rel in pt1-LCLtet cells. Analysis of c-Rel mRNA revealed relatively equal amounts in pt1-LCLtet and control LCLtet cells, indicating that diminished c-Rel protein expression is unrelated to decreased transcription. Finally, a critical role for c-Rel in CD23 regulation was demonstrated by effectively altering c-Rel expression that resulted in the direct modulation of CD23 surface expression. Collectively, these findings demonstrate that low levels of c-Rel are the underlying cause of aberrant CD23 expression in pt1 B cells and are likely to play a critical role in the pathophysiology of this form of HIGM.