bluuebunny/crossref_metadata_2025_split huggingface dataset:
Yap1 Accumulates in the Nucleus in Response to Carbon Stress in
Saccharomyces cerevisiae
Authors: Wiatrowski Heather A. , Carlson Marian 
Published: February 2003

ABSTRACT

Yap1 is a transcription factor of the AP-1 family that is required for the adaptive response to oxidative stress in
Saccharomyces cerevisiae
. We recovered Yap1 in a two-hybrid screen for proteins that interact with the Sip2 subunit of the Snf1 protein kinase, which is required for the adaptation of cells to glucose limitation. Yap1 becomes enriched in the nucleus when cells are subjected to oxidative stress. We show that the localization of Yap1 is similarly sensitive to carbon stress. When glucose-grown cells were shifted to medium containing glycerol or no added carbon source, green fluorescent protein (GFP)-Yap1 accumulated in the nucleus. After adaptation to growth in glycerol, GFP-Yap1 was again primarily cytoplasmic. Nuclear accumulation was independent of respiration and of the Snf1, PKA, TOR, and Yak1 pathways, and the mechanism is distinct from that involved in the response to hydrogen peroxide. Addition of glutathione to the medium inhibited nuclear accumulation of GFP-Yap1 in response to carbon stress but did not affect the relocalization of Gal83 or Mig1. Other stresses such as increased temperature, acidic pH, and ionic stress did not cause nuclear enrichment of GFP-Yap1. These findings suggest a role for Yap1 in the response to carbon stress.
Expressed Sequence Tag Analysis of the Human Pathogen
Paracoccidioides brasiliensis
Yeast Phase: Identification of Putative Homologues of
Candida albicans
Virulence and Pathogenicity Genes
Authors: Goldman Gustavo H. , dos Reis Marques Everaldo , Duarte Ribeiro Diógenes Custódio , de Souza Bernardes Luciano Ângelo , Quiapin Andréa Carla , Vitorelli Patrícia Marostica , Savoldi Marcela , Semighini Camile P. , de Oliveira Regina C. , Nunes Luiz R. , Travassos Luiz R. , Puccia Rosana , Batista Wagner L. , Ferreira Leslie Ecker , Moreira Júlio C. , Bogossian Ana Paula , Tekaia Fredj , Nobrega Marina Pasetto , Nobrega Francisco G. , Goldman Maria Helena S. 
Published: February 2003

ABSTRACT

Paracoccidioides brasiliensis
, a thermodimorphic fungus, is the causative agent of the prevalent systemic mycosis in Latin America, paracoccidioidomycosis. We present here a survey of expressed genes in the yeast pathogenic phase of
P. brasiliensis
. We obtained 13,490 expressed sequence tags from both 5′ and 3′ ends. Clustering analysis yielded the partial sequences of 4,692 expressed genes that were functionally classified by similarity to known genes. We have identified several
Candida albicans
virulence and pathogenicity homologues in
P. brasiliensis
. Furthermore, we have analyzed the expression of some of these genes during the dimorphic yeast-mycelium-yeast transition by real-time quantitative reverse transcription-PCR. Clustering analysis of the mycelium-yeast transition revealed three groups: (i) RBT, hydrophobin, and isocitrate lyase; (ii) malate dehydrogenase, contigs Pb1067 and Pb1145, GPI, and alternative oxidase; and (iii) ubiquitin, delta-9-desaturase, HSP70, HSP82, and HSP104. The first two groups displayed high mRNA expression in the mycelial phase, whereas the third group showed higher mRNA expression in the yeast phase. Our results suggest the possible conservation of pathogenicity and virulence mechanisms among fungi, expand considerably gene identification in
P. brasiliensis
, and provide a broader basis for further progress in understanding its biological peculiarities.
Jumping and kicking in bush crickets
Authors: Burrows Malcolm , Morris Oliver 
Published: February 2003

SUMMARYBush crickets have long, thin hind legs but jump and kick rapidly. The mechanisms underlying these fast movements were analysed by correlating the activity of femoral muscles in a hind leg with the movements of the legs and body captured in high-speed images.A female Pholidoptera griseoaptera weighing 600 mg can jump a horizontal distance of 300 mm from a takeoff angle of 34° and at a velocity of 2.1 m s-1, gaining 1350μJ of kinetic energy. The body is accelerated at up to 114 m s-2, and the tibiae of the hind legs extend fully within 30 ms at maximal rotational velocities of 13 500 deg. s-1. Such performance requires a minimal power output of 40 mW. Ruddering movements of the hind legs may contribute to the stability of the body once the insect is airborne. During kicking, a hind tibia is extended completely within 10 ms with rotational velocities three times higher at 41 800 deg. s-1.Before a kick, high-speed images show no distortions of the hind femoro-tibial joints or of the small semi-lunar groove in the distal femur. Both kicks and jumps can be generated without full flexion of the hind tibiae. Some kicks involve a brief, 40-90 ms, period of co-contraction between the extensor and flexor tibiae muscles, but others can be generated by contraction of the extensor without a preceding co-contraction with the flexor. In the latter kicks, the initial flexion of the tibia is generated by a burst of flexor spikes, which then stop before spikes occur in the fast extensor tibiae(FETi) motor neuron. The rapid extension of the tibia can follow directly upon these spikes or can be delayed by as long as 40 ms. The velocity of tibial movement is positively correlated with the number of FETi spikes.The hind legs are 1.5 times longer than the body and more than four times longer than the front legs. The mechanical advantage of the hind leg flexor muscle over the extensor is greater at flexed joint angles and is enhanced by a pad of tissue on its tendon that slides over a protuberance in the ventral wall of the distal femur. The balance of forces in the extensor and flexor muscles, coupled with their changing lever ratio at different joint positions,appears to determine the point of tibial release and to enable rapid movements without an obligatory co-contraction of the two muscles.
Acutely altered hemodynamics following venous obstruction in the early chick embryo
Authors: Stekelenburg-de Vos Sandra , Ursem Nicolette T. C. , Hop Wim C. J. , Wladimiroff Juriy W. , Gittenberger-de Groot Adriana C. , Poelmann Robert E. 
Published: February 2003

SUMMARYIn the venous clip model specific cardiac malformations are induced in the chick embryo by obstructing the right lateral vitelline vein with a microclip. Clipping alters venous return and intracardiac laminar blood flow patterns,with secondary effects on the mechanical load of the embryonic myocardium. We investigated the instantaneous effects of clipping the right lateral vitelline vein on hemodynamics in the stage-17 chick embryo. 32 chick embryos HH 17 were subdivided into venous clipped (N=16) and matched control embryos(N=16). Dorsal aortic blood flow velocity was measured with a 20 MHz pulsed Doppler meter. A time series of eight successive measurements per embryo was made starting just before clipping and ending 5h after clipping. Heart rate, peak systolic velocity, time-averaged velocity, peak blood flow,mean blood flow, peak acceleration and stroke volume were determined. All hemodynamic parameters decreased acutely after venous clipping and only three out of seven parameters (heart rate, time-averaged velocity and mean blood flow) showed a recovery to baseline values during the 5h study period. We conclude that the experimental alteration of venous return has major acute effects on hemodynamics in the chick embryo. These effects may be responsible for the observed cardiac malformations after clipping.
Erotomanic stalking in evolutionary perspective
Authors: Brüne Martin 
Published: February 2003

AbstractErotomania, the delusion of being loved by another person, comprises marked sex differences concerning prevalence rates and behavior. Whereas traditional psychiatry has considered erotomania to be almost entirely restricted to women, recent studies have revealed that criminal offenses associated with the condition occur much more frequently in men. The main hypothesis of this article is that these findings may be explained in terms of evolutionary theory. Erotomania, accordingly, may be viewed as a pathological variant of a specific sexual strategy that evolved under selection pressures of the human environment of evolutionary adaptedness. The overt behavior is related to the pursuit of long‐term mating, its potentially beneficial effect on inclusive fitness of the individual, and disparate strategies of the sexes to ensure sexual fidelity of the potential partner. Therefore, the evolutionary approach provides a plausible explanation as to why forensically relevant erotomania prevails in men. The pathological process of delusional misinterpretation of perceived signals from the social environment itself may result from poor reality testing due to a failure of social meta‐cognition. The evolutionary perspective may provide additional insights into the nature of sex‐specific behaviors and may improve our understanding of forensically relevant behaviors. Copyright © 2002 John Wiley & Sons, Ltd.
Determination of intracellular efficacies of azithromycin againstLeishmania majorinfection in human neutrophilsin vitro
Authors: Tanyuksel Mehmet , Bas A. Levent , Araz Engin , Aybay Cemalettin 
Published: February 2003

AbstractAzithromycin is one of a new class of antibiotics known as azalides. Azithromycin has high tissue affinity and this feature is thought to be due to the presence of two basic tertiary amine groups.Leishmania major, one of the causative agents of cutaneous leishmaniosis, is an obligate intracellular parasite. In thisin vitrostudy, the potential anti‐leishmanial effect of azithromycin upon intracellular forms namely the amastigote ofL. majorin mice peritoneal macrophages was investigated.L. majorpromastigotes were propagated in RPMI‐1640 supplemented with 20% fetal calf serum in the log phase. The percentage of phagocytosis and microbiacidal activity of azithromycin on macrophages was assessed in the control and study groups by fluorescence microscopy, using acridine orange. Our results showed that at all the concentrations used (0.05, 0.1, 0.3, 0.6 μg ml−1) azithromycin had no inhibitory effect on the phagocytic capacity of mouse peritoneal macrophages. Although no significant difference was observed for leishmaniacidal activity between the study and the control groups at a concentration of 0.05 μg ml−1(p>0.05), a significant (p<0.05) increase in leishmaniacidal activity was detected at 0.1, 0.3 and 0.6 μg ml−1. As a result, azithromycin does not provide any contribution to the phagocytosis ofL. majorpromastigotes in macrophagesin vitro, but it increases the intracellular killing rates of amastigotes. These results suggest that it has a potential anti‐leishmanial effect, and may provide a significant advantage in the treatment of the disease. Copyright © 2002 John Wiley & Sons, Ltd.
Effect of cobalt on the oxidative status in heart and aorta of streptozotocin‐induced diabetic rats
Authors: Yildirim Özlem , Büyükbingöl Zeliha 
Published: February 2003

AbstractEffects of cobalt on the antioxidant status of control and streptozotocin diabetic rat heart and aorta were examined at the second, fourth and sixth week of treatment. Rats were divided into four groups: control, diabetic, control treated with cobalt chloride and diabetic treated with cobalt chloride. Diabetes was induced by tail vein injection of streptozotocin (STZ). Cobalt treatment groups were given 0.5 mM of CoCl2 in drinking water. The rats in both groups were further subdivided into three groups of six rats each. Rats in these subgroups were studied at 2‐week intervals up to 6 weeks. At the end of the experiment, all animals were sacrified by decapitation, heart and aorta samples were removed for determination of thiobarbituric acid reactive substance (TBARS) level and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH‐Px) activities. It was found that lipid peroxidation levels and antioxidant enzyme activities were increased in the streptozotocin‐induced diabetic rats at all times studied. Cobalt treatment of diabetic rats (0.5 mM in drinking water) resulted in attenuation of the increased levels of TBARS and antioxidant enzyme activities in heart and aorta. Thus, the effect of oral administration of cobalt at this dose during the early stage of experimental diabetes can be considered as a consequence of altered endogenous defence mechanisms in heart and aorta. Copyright © 2002 John Wiley & Sons, Ltd.
Role of latent heat in chiral symmetry breaking transition in the crystallization of 1,1′‐binaphthyl
Authors: Asakura Kouichi , Hayashi Masato , Osanai Shuichi 
Published: February 2003

AbstractThe influence of latent heat dissipated by the crystallization of 1,1′‐binaphthyl in its supercooled molten state on the chiral symmetry breaking transition was investigated. Temperature change in the crystallization system was monitored by infrared thermocamera. Temperature rise due to the dissipation of latent heat in the growing front of polycrystalline aggregate was about 2°C in an unstirred crystallization system. The melting point of racemic mixture and racemic compound of 1,1′‐binaphthyl is 145°C and 158°C, respectively. The latent heat generated by the crystallization could thus change the crystallization behavior when the initial temperature of the melt was slightly lower than 145°C. The temperature change in both unstirred and stirred crystallization systems was monitored. In the stirred crystallization system, even in the case when the initial temperature of the melt was about 2°C lower than 145°C, the temperature rose by about 4°C immediately after the onset of crystallization. This indicates that the role of stirring as the critical parameter for the chiral symmetry breaking transition is not only to clone the chiral crystals but also to enhance the dissipation of latent heat due to secondary nucleation. Chirality 15:238–241, 2003. © 2003 Wiley‐Liss, Inc.
Chiral reagents for the determination of enantiomeric excess and absolute configuration using NMR spectroscopy
Authors: Wenzel Thomas J. , Wilcox James D. 
Published: February 2003

AbstractRecent advances in the development of chiral derivatizing and solvating agents that facilitate the determination of enantiomeric excess and absolute configuration are reviewed. These include metal‐containing species, host–guest systems, donor–acceptor compounds, and liquid crystal discriminating agents. In the aggregate, these reagents can be used to analyze a wide range of compound classes. Chirality 15:256–270, 2003. © 2003 Wiley‐Liss, Inc.
Evaluation of absolute configuration of naphthylphenyl‐substituted oligosilanes by CD exciton chirality method
Authors: Oh Hyun‐Shik , Imae Ichiro , Kawakami Yusuke 
Published: February 2003

AbstractAbsolute configurations of methylnaphthylphenyl‐substituted oligosilanes, MeNpPhSi*SiMeR1R2[2(R1, R2=Me),3(R1=Me, R2=Ph),4(R1, R2=Ph), and5(R1=Me, R2=SiMe3)] were predicted by circular dichroism (CD) exciton chirality method. The σ–π conjugation effect of oligosilylene units (σ‐linkage) with π‐electron systems caused an intense red‐shift of1La,Phtransition band of the oligosilanes as shown in UV/VIS and made it possible to observe clear CD exciton chirality between the two aromatic chromophores on chiral silicon atom. Chirality 15:231–237, 2003. © 2003 Wiley‐Liss, Inc.
Crosslinking of biological tissues using genipin and/or carbodiimide
Authors: Sung Hsing‐Wen , Chang Wen‐Hisang , Ma Chiun‐Yuang , Lee Meng‐Horng 
Published: February 2003

AbstractThe study was to investigate the crosslinking characteristics, mechanical properties, and resistance against enzymatic degradation of biological tissues after fixation with genipin (a naturally occurring crosslinking agent) and/or carbodiimide. Fresh tissue was used as a control. It was found that both genipin and carbodiimide are effective crosslinking agents for tissue fixation and genipin crosslinking is comparatively slower than carbodiimide crosslinking. Additionally, tissue fixation in genipin and/or carbodiimide may produce distinct crosslinking structures. Carbodiimide may form intrahelical and interhelical crosslinks within or between tropocollagen molecules, whereas genipin may further introduce intermicrofibrillar crosslinks between adjacent collagen microfibrils. The stability (denaturation temperature and resistance against enzymatic degradation) of the fixed tissue is mainly determined by its intrahelical and interhelical crosslinks. In contrast, intermicrofibrillar crosslinks significantly affect the mechanical properties (tissue shrinkage during fixation, tensile strength, strain at break, and ruptured pattern) of the fixed tissue. Moreover, the degree of enzymatic degradation of the fixed tissue may be influenced by three factors: the availability, to the enzyme, of recognizable cleavage sites, the degree of crosslinking, and the extent of helical integrity of tropocollagen molecules in tissue. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 64A: 427–438, 2003
Neural differentiation of midbrain cells on various protein‐immobilized polyethylene films
Authors: Nakaoka Ryusuke , Tsuchiya Toshie , Nakamura Akitada 
Published: February 2003

AbstractThe effect of surface modification of polyethylene (PE) film on differentiation of midbrain (MB) cells obtained from rat embryos was determined by their micromass culture system. When cultured on untreated PE film, cell differentiation was suppressed to approximately two‐thirds of that observed in a control culture dish. On the contrary, type I collagen‐immobilized PE film increased differentiated foci of the MB cells more than did the untreated PE film. RGDS (Arg‐Gly‐Asp‐Ser) peptide immobilization onto PE film resulted in almost the same differentiation activity as the collagen immobilized PE film. Bovine serum albumin (BSA) immobilization onto PE film enhance the differentiation activity more than did the untreated PE film, but not up to the levels of collagen‐ and RGDS‐immobilized PE. The number of differentiated foci of the MB cells on untreated PE film were increased by the addition of the condition medium prepared from the collagen‐immobilized PE film. However, the number of foci was not increased by the addition of other condition media obtained from control dish, untreated, BSA‐, and RGDS‐immobilized PE. On the other hand, none of these condition media enhanced a differentiation of the neuronal cell line of PC12 cells, suggesting that some factors effectively differentiate midbrain cells, composed of neuronal epithelial and mesenchymal cells, but not the PC12 cells secreted in the condition media prepared from collagen‐immobilized PE. In addition, it is probable that neural growth factor was not secreted in these condition media, which could not induce the differentiation of PC12 cells. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 64A: 439–446, 2003
Biosynthetic response of passaged chondrocytes in a type II collagen scaffold to mechanical compression
Authors: Lee C. R. , Grodzinsky A. J. , Spector M. 
Published: February 2003

AbstractTo investigate the potential utility of mechanical loading in articular cartilage tissue engineering, porous type II collagen scaffolds seeded with adult canine passaged chondrocytes were subjected to static and dynamic compressions of varying magnitudes (0–50% static strain) and durations (1–24 h), and at different times during culture (2–30 days postseeding). The effects of mechanical compression on the biosynthetic activity of the chondrocytes were evaluated by measuring the amount of 3H‐proline‐labeled proteins and 35S‐sulfate‐labeled proteoglycans that accumulated in the cell‐scaffold construct and was released to the medium during the loading period. Similar to published results on loading of articular cartilage explants, static compression decreased protein and proteoglycan biosynthesis in a time‐ and dose‐dependent manner (each p < 0.005), and selected dynamic compression protocols were able to increase rates of biosynthesis (p < 0.05). The main difference between the results seen for this tissue engineering system and cartilage explants was in the amount of newly synthesized matrix molecules that accumulated within the construct under dynamic loading, with less accumulating in the type II collagen scaffold. In summary, the general biosynthetic response of passaged chondrocytes in the porous type II collagen scaffolds is similar to that seen for chondrocytes in their native environment. Future work needs to be directed to modifications of the cell‐seeded construct to allow for the capture of the newly synthesized matrix molecules by the scaffold. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 64A: 560–569, 2003
Early up‐regulation of chemokine expression in fulminant hepatic failure
Authors: Leifeld Ludger , Dumoulin Franz‐Ludwig , Purr Ingvill , Janberg Katrin , Trautwein Christian , Wolff Martin , Manns Michael Peter , Sauerbruch Tilman , Spengler Ulrich 
Published: February 2003

AbstractCC‐chemokines recruit and activate macrophages and T lymphocytes, the major components of inflammatory infiltrates in fulminant hepatic failure (FHF). To analyse the role of CC‐chemokines in the pathogenesis of FHF, this study examined serum levels and intrahepatic expression of MCP‐1, MIP‐1α, MIP‐1β, and RANTES in the livers and sera of patients with FHF and controls by ELISA, immunohistochemistry, and competitive RT‐PCR. Serum levels and intrahepatic expression of all chemokines studied in FHF exceeded the levels in chronic liver diseases and normal controls. Distinct patterns of expression of each chemokine were noted on Kupffer cells, sinusoidal endothelial cells, hepatocytes, lymphocytes, and bile ducts. Intrahepatic chemokine expression correlated closely with the extent of infiltration by macrophages and T lymphocytes (r = 0.65–0.95, p < 0.001). The functional relationship between intrahepatic chemokine release and infiltration was confirmed in chemotaxis assays by inhibiting chemotaxis induced by homogenates of liver tissue obtained from FHF patients with neutralizing MCP‐1, MIP‐1α, MIP‐1β, and RANTES antibodies. The time course of CC‐chemokine release was studied in the concanavalin A and the galactosamine/LPS mouse models of FHF. In both models, intrahepatic chemokine up‐regulation occurred as an early event prior to hepatic infiltration and liver damage. The data indicate that an abundant intrahepatic release of CC‐chemokines is an early and pivotal step in the pathogenesis of FHF. Copyright © 2003 John Wiley & Sons, Ltd.