bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relationship between systemic nitric oxide metabolites and cyclic GMP in healthy male volunteers
Authors: Metzger I. F. , Sertorio J. T. C. , Tanus‐Santos J. E. 
Published: August 2006

AbstractAim:  Nitric oxide (NO) is an endogenous mediator of many physiological processes, many of which are mediated by cyclic guanosine 3′,5′‐monophosphate (cGMP). Much effort has been made to validate clinical markers of NO production or bioavailability. While the measurement of plasma nitrate, nitrite, and cGMP concentrations have been suggested to reflect endogenous production of NO, there is no study showing whether there is correlation between these three markers. In the present study, we investigate whether there is correlation between the plasma concentrations of nitrate, nitrite, and cGMP in a relatively homogeneous group of 141 healthy subjects.Methods:  Venous blood samples were collected from healthy male subjects and plasma aliquots were then immediately removed and stored at −70 °C until analysed in duplicate for their nitrite and nitrate content using ozone‐based chemiluminescence assays. Plasma cGMP levels were determined by using a commercial enzyme immunoassay.Results:  While we found no significant correlation between plasma nitrite and nitrate concentrations (P = 0.747), or between plasma nitrate and cGMP concentrations (P = 0.221), a significant positive correlation was found between plasma cGMP and nitrite concentrations (P = 0.017, rs = 0.270).Conclusions:  The significant correlation we found between plasma nitrite and cGMP concentrations is consistent with the notion that nitrite or cGMP concentrations in plasma may be useful clinical markers of NO formation in healthy subjects.
Functional Analysis of the
ATG8
Homologue Ao
atg8
and Role of Autophagy in Differentiation and Germination in
Aspergillus oryzae
Authors: Kikuma Takashi , Ohneda Mamoru , Arioka Manabu , Kitamoto Katsuhiko 
Published: August 2006

ABSTRACT

Autophagy is a well-known degradation system, induced by nutrient starvation, in which cytoplasmic components and organelles are digested via vacuoles/lysosomes. Recently, it was reported that autophagy is involved in the turnover of cellular components, development, differentiation, immune responses, protection against pathogens, and cell death. In this study, we isolated the
ATG8
gene homologue Ao
atg8
from the filamentous fungus
Aspergillus oryzae
and visualized autophagy by the expression of DsRed2-AoAtg8 and enhanced green fluorescent protein-AoAtg8 fusion proteins in this fungus. While the fusion proteins were localized in dot structures which are preautophagosomal structure-like structures under normal growth conditions, starvation or rapamycin treatment caused their accumulation in vacuoles. DsRed2 expressed in the cytoplasm was also taken up into vacuoles under starvation conditions or during the differentiation of conidiophores and conidial germination. Deletion mutants of Ao
atg8
did not form aerial hyphae and conidia, and DsRed2 was not localized in vacuoles under starvation conditions, indicating that Ao
atg8
is essential for autophagy. Furthermore, Ao
atg8
conditional mutants showed delayed conidial germination in the absence of nitrogen sources. These results suggest that autophagy functions in both the differentiation of aerial hyphae and in conidial germination in
A. oryzae
.
Sorting Signals Required for Trafficking of the Cysteine-Rich Acidic Repetitive Transmembrane Protein in
Trypanosoma brucei
Authors: Qiao Xugang , Chuang Bin-Fay , Jin Yamei , Muranjan Madhavi , Hung Chien-Hui , Lee Pei-Tseng , Lee Mary Gwo-Shu 
Published: August 2006

ABSTRACT

In trypanosomatids, endocytosis and exocytosis are restricted to the flagellar pocket (FP). The
c
ysteine-
r
ich
a
cidic repetitive trans
m
embrane (CRAM) protein is located at the FP of
Trypanosoma brucei
and potentially functions as a receptor or an essential component for lipoprotein uptake. We characterized sorting determinants involved in efficient trafficking of CRAM to and from the FP of
T. brucei
. Previous studies indicated the presence of signals in the CRAM C terminus, specific for its localization to the FP and for efficient endocytosis (H. Yang, D. G. Russell, B. Zeng, M. Eiki, and M.G.-S. Lee, Mol. Cell. Biol. 20:5149-5163, 2000.) To delineate functional domains of putative sorting signals, we performed a mutagenesis series of the CRAM C terminus. Subcellular localization of CRAM mutants demonstrated that the amino acid sequence between −5 and −14 (referred to as a transport signal) is essential for exporting CRAM from the endoplasmic reticulum to the FP, and mutations of amino acids at −12 (V), −10 (V), or −5 (D) led to retention of CRAM in the endoplasmic reticulum. Comparison of the endocytosis efficiency of CRAM mutants demonstrated that the sequence from amino acid −5 to −23 (referred to as a putative endocytosis signal) is required for efficient endocytosis and overlaps with the transport signal. Apparently the CRAM-derived sorting signal can efficiently interact with the
T. brucei
μ1 adaptin, and mutations at amino acids essential for the function of the transport signal abolished the interaction of the signal with
T. brucei
μ1, strengthening the hypothesis of the involvement of the clathrin- and adaptor-dependent pathway in trafficking of CRAM via the FP.
Transcriptomic Analysis of Extensive Changes in Metabolic Regulation in
Kluyveromyces lactis
Strains
Authors: Suleau Audrey , Gourdon Pierre , Reitz-Ausseur Joëlle , Casaregola Serge 
Published: August 2006

ABSTRACT

Genome-wide analysis of transcriptional regulation is generally carried out on well-characterized reference laboratory strains; hence, the characteristics of industrial isolates are therefore overlooked. In a previous study on the major cheese yeast
Kluyveromyces lactis
, we have shown that the reference strain and an industrial strain used in cheese making display a differential gene expression when grown on a single carbon source. Here, we have used more controlled conditions, i.e., growth in a fermentor with pH and oxygen maintained constant, to study how these two isolates grown in glucose reacted to an addition of lactose. The observed differences between sugar consumption and the production of various metabolites, ethanol, acetate, and glycerol, correlated with the response were monitored by the analysis of the expression of 482 genes. Extensive differences in gene expression between the strains were revealed in sugar transport, glucose repression, ethanol metabolism, and amino acid import. These differences were partly due to repression by glucose and another, yet-unknown regulation mechanism. Our results bring to light a new type of
K. lactis
strain with respect to hexose transport gene content and repression by glucose. We found that a combination of point mutations and variation in gene regulation generates a biodiversity within the
K. lactis
species that was not anticipated. In contrast to
S. cerevisiae
, in which there is a massive increase in the number of sugar transporter and fermentation genes, in
K. lactis
, interstrain diversity in adaptation to a changing environment is based on small changes at the level of key genes and cell growth control.
Stress-Specific Role of Fission Yeast Gcn5 Histone Acetyltransferase in Programming a Subset of Stress Response Genes
Authors: Johnsson Anna , Xue-Franzén Yongtao , Lundin Maria , Wright Anthony P. H. 
Published: August 2006

ABSTRACT

Gcn5 is a coactivator protein that contributes to gene activation by acetylating specific lysine residues within the N termini of histone proteins. Gcn5 has been intensively studied in the budding yeast,
Saccharomyces cerevisiae
, but the features of genes that determine whether they require Gcn5 during activation have not been conclusively clarified. To allow comparison with
S. cerevisiae
, we have studied the genome-wide role of Gcn5 in the distantly related fission yeast,
Schizosaccharomyces pombe
. We show that Gcn5 is specifically required for adaptation to KCl- and CaCl
2
-mediated stress in
S. pombe
. We have characterized the genome-wide gene expression responses to KCl stress and show that Gcn5 is involved in the regulation of a subset of stress response genes. Gcn5 is most clearly associated with KCl-induced genes, but there is no correlation between Gcn5 dependence and the extent of their induction. Instead, Gcn5-dependent KCl-induced genes are specifically enriched in four different DNA motifs. The Gcn5-dependent KCl-induced genes are also associated with biological process gene ontology terms such as carbohydrate metabolism, glycolysis, and nicotinamide metabolism that together constitute a subset of the ontology parameters associated with KCl-induced genes.
In Vitro Generation of Human High-Density-Lipoprotein-Resistant
Trypanosoma brucei brucei
Authors: Faulkner Sara D. , Oli Monika W. , Kieft Rudo , Cotlin Laura , Widener Justin , Shiflett April , Cipriano Michael J. , Pacocha Sarah E. , Birkeland Shanda R. , Hajduk Stephen L. , McArthur Andrew G. 
Published: August 2006

ABSTRACT

The host range of African trypanosomes is influenced by innate protective molecules in the blood of primates. A subfraction of human high-density lipoprotein (HDL) containing apolipoprotein A-I, apolipoprotein L-I, and haptoglobin-related protein is toxic to
Trypanosoma brucei brucei
but not the human sleeping sickness parasite
Trypanosoma brucei rhodesiense
. It is thought that
T. b. rhodesiense
evolved from a
T. b. brucei
-like ancestor and expresses a defense protein that ablates the antitrypanosomal activity of human HDL. To directly investigate this possibility, we developed an in vitro selection to generate human HDL-resistant
T. b. brucei
. Here we show that conversion of
T. b. brucei
from human HDL sensitive to resistant correlates with changes in the expression of the variant surface glycoprotein (VSG) and abolished uptake of the cytotoxic human HDLs. Complete transcriptome analysis of the HDL-susceptible and -resistant trypanosomes confirmed that VSG switching had occurred but failed to reveal the expression of other genes specifically associated with human HDL resistance, including the serum resistance-associated gene (
SRA
) of
T. b. rhodesiense
. In addition, we found that while the original active expression site was still utilized, expression of three expression site-associated genes (
ESAG
) was altered in the HDL-resistant trypanosomes. These findings demonstrate that resistance to human HDLs can be acquired by
T. b. brucei
.
Fungal Metabolic Model for Tyrosinemia Type 3: Molecular Characterization of a Gene Encoding a 4-Hydroxy-Phenyl Pyruvate Dioxygenase from
Aspergillus nidulans
Authors: da Silva Ferreira Márcia Eliana , Savoldi Marcela , Sueli Bonato Pierina , Goldman Maria Helena S. , Goldman Gustavo H. 
Published: August 2006

ABSTRACT

Mutations in the human HPD gene (encoding 4-hydroxyphenylpyruvic acid dioxygenase) cause hereditary tyrosinemia type 3 (HT3). We deleted the
Aspergillus nidulans
homologue (
hpdA
). We showed that the mutant strain is not able to grow in the presence of phenylalanine and that it accumulates increased concentrations of tyrosine and 4-hydroxyphenylpyruvic acid, mimicking the human HT3 phenotype.
Physical activity during treatment in children with leukemia: a pilot study
Authors: Aznar Susana , Webster Anthony L. , San Juan Alejandro F. , Chamorro-Viña Carolina , Maté-Muñoz José L. , Moral Susana , Pérez Margarita , García-Castro Javier , Ramírez Manuel , Madero Luis , Lucia Alejandro 
Published: August 2006

The purpose of this pilot study was to measure physical activity (PA) levels in children undergoing treatment for acute lymphoblastic leukemia (ALL) and to compare the results with those from age-matched healthy children. We used the MTI Actigraph accelerometer to determine PA (during a 1 week period) in children (n = 7; age = 4–7 y) undergoing maintenance treatment for ALL and in age-matched controls (n = 7). The number of children accumulating at least 60 min of moderate-to-vigorous physical activity (MVPA) for 5 or more days of the week was 3 for the control group, whereas no children with ALL met this criterion. Significantly lower levels of total weekly time of MVPA were seen in children being treated for ALL (328 ± 107 min) than in controls (506 ± 175 min) (p < 0.05). When weekday data was analyzed, the ALL patients also had significantly lower mean daily times of MVPA (49 ± 23 min vs. 79 ± 25 min). It is thus important that young ALL sufferers are encouraged to participate in appropriate sports, games, and physical activities both in the family and school environments that will prime them with positive attitudes to PA during the critical early years of life.
Effects of physical conditioning on lipids and arachidonic acid metabolites in untrained boys: a longitudinal study
Authors: Stergioulas Apostolos Thomas , Filippou Dimitrios Konstantinos 
Published: August 2006

In addition to a variety of lipids, 2 products of the arachidonic acid cascade, prostacyclin and thromboxane, are involved in the pathogenesis of atherosclerosis as a result of their effects on platelet function and on the vascular endothelium. The aim of the present investigation was to ascertain if a sub-maximal 8 week endurance training period followed by a 4 week detraining period would have any effects on high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC), triglycerides (TG), 2,3-dinor-6-keto-prostaglandin F1α(2,3-dinor-6-keto-PGF1α), the urinary metabolite of prostacyclin, 2,3-dinor-thromboxane B2(2,3-dinor-TXB2), the urinary metabolite of thromboxane, and the ratios of TC to HDL-C and of 2,3 dinor-6-keto-PGF1αto 2,3-dinor-TXB2. Thirty-eight boys aged 10–14 were randomly divided into exercise (n = 21) and control (n = 17) groups. The exercise group trained on a bicycle ergometer 4 times/week, 1 h/session, at 80% of their physical working capacity at a heart rate of 170 beats/min (PWC170), for 8 weeks. The control group did not participate in any specific physical exercise program. The results showed that relative to the control group, the exercise group had a significant increase in HDL-C and 2,3-dinor-6-keto-PGF1αconcentrations at the end of the 4th (p < 0.05 and p < 0.001, respectively) and the 8th week (p < 0.01 and p < 0.001) of training, respectively; a significant increase in the 2,3 dinor-6-keto-PGF1α– 2,3-dinor-TXB2ratio (p < 0.05 and p < 0.01 at the same intervals); a significant decrease in TG at the end of the 8th week of training (p < 0.05); and a significant decrease in the TC–HDL-C ratio at the end of the 4th (p < 0.05) and 8th weeks of training (p < 0.001).
Viability of the isolated soleus muscle during long-term incubation
Authors: Alkhateeb Hakam , Chabowski Adrian , Bonen Arend 
Published: August 2006

Skeletal muscle metabolism has been examined in perfused hindlimb muscles and in isolated muscle preparations. While long-term viability of the fast-twitch epitrochlearis has been documented with respect to glucose transport, it appears that long-term incubated soleus muscles are less stable when incubated ex vivo for many hours. Therefore, in the present study, we have examined whether the isolated soleus muscle remains metabolically viable for up to 18 h with respect to maintaining ATP and phosphocreatine (PCr) concentrations, carbohydrate and fatty-acid metabolism, insulin signalling, and protein expression. Soleus muscles were incubated in well-oxygenated Medium 199 (M199) supplemented with low concentrations of insulin (14.3 µU/mL) for 0, 6, 12, and 18 h. During this incubating period the concentrations of ATP and PCr were stable, indicating that oxygenation and substrate supply were being maintained. In addition, the concentrations of proglycogen and macroglycogen were not altered, whereas an increase (+30%) in intramuscular triacylglycerol concentration was observed at the end of 18 h of incubation (p < 0.05). Complex molecular processes in the long-term incubated muscles were also stable. This was shown by maintenance of basal as well as insulin-stimulated rates of 3-O-methyl glucose transport, and by the maintenance of protein expression of the glucose transporter GLUT4 and the fatty acid transporters FAT/CD36 and FABPpm. In addition, the insulin-stimulated translocation of GLUT4 to the plasma membrane, which involves a complex signalling cascade, was fully preserved. In conclusion, in well-oxygenated soleus muscles maintained in M199 supplemented with extremely low concentrations of insulin, ATP and PCr concentrations, carbohydrate and fatty acid metabolism, insulin signalling, and protein expression were stably maintained for up to 18 h. This provides for opportunities to examine muscle metabolic function under very highly controlled conditions.
In vivo effect ofTrigonella foenum graecumon the expression of pyruvate kinase, phosphoenolpyruvate carboxykinase, and distribution of glucose transporter (GLUT4) in alloxan-diabetic rats
Authors: Mohammad Sameer , Taha Asia , Akhtar Kamal , Bamezai R.N.K. , Baquer Najma Zaheer 
Published: August 2006

Plasma glucose levels are maintained by a precise balance between glucose production and its use. Liver pyruvate kinase (PK) and phosphoenolpyruvate carboxykinase (PEPCK), 2 key enzymes of glycolysis and gluconeogenesis, respectively, play a crucial role in this glucose homeostasis along with skeletal muscle glucose transporter (GLUT4). In the diabetic state, this balance is disturbed owing to the absence of insulin, the principal factor controlling this regulation. In the present study, alloxan-diabetic animals having high glucose levels of more than 300 mmol/L have been taken and the administration of Trigonella seed powder (TSP) to the diabetic animals was assessed for its effect on the expression of PK and PEPCK in liver and GLUT4 distribution in skeletal muscle of alloxan-diabetic rats. TSP treatment to the diabetic animals resulted in a marked decrease in the plasma glucose levels. Trigonella treatment partially restored the altered expression of PK and PEPCK. TSP treatment also corrected the alterations in the distribution of GLUT4 in the skeletal muscle.
Sodium-, chloride-, and mibefradil-sensitive calcium channels in intestinal pacing in wild-type and W/WV mice
Authors: Boddy Geoffrey , Willis A. , Galante G. , Daniel E.E. 
Published: August 2006

Pacing of intestinal smooth muscle is driven by a network of cells found in the myenteric plexus called the interstitial cells of Cajal (ICC-MP), which produce a rhythmic pacemaker current. Using intact segments of circular (CM) and longitudinal (LM) muscle from wild-type and W/WV mice, we found that sodium-, chloride-, and mibefradil-sensitive ion channel currents are required for normal pacing to occur. Application of 30 µmol/L and 300 µmol/L lidocaine, 1 mmol/L 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid (DIDS), 50 nmol/L and 500 nmol/L mibefradil, or low sodium Krebs significantly reduced pacing frequency in LM and CM. However, simultaneously applying DIDS and lidocaine or low sodium Krebs solution did not completely block pacing nor did it have an additive effect. Lidocaine and low sodium Krebs solution also abolished the gradient of pacing frequencies (higher proximally) found throughout the intestine, resulting in a uniform contraction frequency of 30–40/min. In W/WV mice, which lack ICC-MP, application of DIDS and lidocaine had no effect on the robust pacing in LM segments. In conclusion we found that sodium-, chloride-, and mibefradil-sensitive channel activities were required for normal pacing and to maintain the pacing gradient found throughout the intestines in wild-type but not W/WV mice.
Early activation and redistribution of calpain activity in skeletal muscle during hindlimb unweighting and reweighting
Authors: Enns Deborah L. , Belcastro Angelo N. 
Published: August 2006

The aims of this study were the following: (i) to determine whether activation of the Ca2+-activated protease, calpain, is an early event during hindlimb unweighting (HU) in skeletal muscle; and (ii) to assess whether calpain activity is greater during reweighting compared with HU alone. Rats were exposed to 12, 24, and 72 h, or 9 d of HU, followed by reweighting for 0, 12, or 24 h. Calpain activities were assayed for total, soluble, and particulate fractions. Total calpain activity was increased in the soleus at all HU time points, whereas activities were elevated in the gastrocnemius only after 9 d of HU. With reweighting, calpain activity remained elevated at all time points for both muscles. In general, reweighting the gastrocnemius increased its calpain activity more than during HU only, whereas reweighting the soleus did not produce additional increases in its calpain activity. The increases in calpain activity were associated with a proportional increase in activity of the particulate (membrane- and protein-associated) fraction. The results suggest that calpain activation is an early event during HU in the soleus, and that the increases in calpain activity in both muscles are associated with a redistribution of activity from cytosolic to particulate fractions.
Magnesium deficiency augments myocardial response to reactive oxygen species
Authors: Manju L. , Nair R. Renuka 
Published: August 2006

Magnesium (Mg) deficiency and oxidative stress are independently implicated in the etiopathogenesis of various cardiovascular disorders. This study was undertaken to examine the hypothesis that Mg deficiency augments the myocardial response to oxidative stress. Electrically stimulated rat papillary muscle was used for recording the contractile variation. Biochemical variables of energy metabolism (adenosine triphosphate (ATP) and creatine phosphate) and markers of tissue injury (lactate dehydrogenase (LDH) release and lipidperoxidation), which can affect myocardial contractility, were assayed in Langendorff-perfused rat hearts. Hydrogen peroxide (100 µmol/L) was used as the source of reactive oxygen species. The negative inotropic response to H2O2was significantly higher in Mg deficiency (0.48 mmol Mg/L) than in Mg sufficiency (1.2 mmol Mg/L). Low Mg levels did not affect ATP levels or tissue lipid peroxidation. However, H2O2induced a decrease in ATP; enhanced lipid peroxidation and the release of LDH were augmented by Mg deficiency. Increased lipid peroxidation associated with a decrease in available energy might be responsible for the augmentation of the negative inotropic response to H2O2in Mg deficiency. The observations from this study validate the hypothesis that myocardial response to oxidative stress is augmented by Mg deficiency. This observation has significance in ischemia–reperfusion injury, where Mg deficiency can have an additive effect on the debilitating consequences.
A dogged pursuit of coincidence
Authors: Joris Philip X. 
Published: August 2006

This essay looks at the historical significance or two APS papers that are freely available online: Goldberg JM and Brown PB. Response of binaural neurons of dog superior olivary complex to dichotic tonal stimuli: some physiological mechanisms of sound localization, J Neurophysiol 32: 613–636, 1969 ( http://jn.physiology.org/cgi/reprint/32/4/613 ). Yin TCT and Chan J. Interaural time sensitivity in medial superior olive of cat, J Neurophysiol 64: 465–488, 1990 ( http://jn.physiology.org/cgi/reprint/64/2/465 ).