bluuebunny/crossref_metadata_2025_split huggingface dataset:
Guanosine promotes the up‐regulation of inward rectifier potassium current mediated by Kir4.1 in cultured rat cortical astrocytes
Authors: Benfenati Valentina , Caprini Marco , Nobile Mario , Rapisarda Carmela , Ferroni Stefano 
Published: May 2006

AbstractGuanosine (Guo) is an endogenous neuroprotective molecule of the CNS, which has various acute and long‐term effects on both neurones and astroglial cells. Whether Guo also modulates the activity/expression of ion channels involved in homeostatic control of extracellular potassium by the astrocytic syncytium is still unknown. Here we provide electrophysiological evidence that chronic exposure (48 h) to Guo (500 μm) promotes the functional expression of an inward rectifier K+ (Kir) conductance in primary cultured rat cortical astrocytes. Molecular screening indicated that Guo promotes the up‐regulation of the Kir4.1 channel, the major component of the Kir current in astroglia in vivo. Furthermore, the properties of astrocytic Kir current overlapped those of the recombinant Kir4.1 channel expressed in a heterologous system, strongly suggesting that the Guo‐induced Kir conductance is mainly gated by Kir4.1. In contrast, the expression levels of two other Kir channel proteins were either unchanged (Kir2.1) or decreased (Kir5.1). Finally, we showed that inhibition of translational process, but not depression of transcription, prevents the Guo‐induced up‐regulation of Kir4.1, indicating that this nucleoside acts through de novo protein synthesis. Because accumulating data indicate that down‐regulation of astroglial Kir current contributes to the pathogenesis of neurodegenerative diseases associated with dysregulation of extracellular K+ homeostasis, these results support the notion that Guo might be a molecule of therapeutic interest for counteracting the detrimental effect of K+‐buffering impairment of the astroglial syncytium that occurs in pathological conditions.
Protective role of caffeic acid phenethyl ester in the liver of rats exposed to cold stress
Authors: Ates Burhan , Ilker Dogru M. , Gul Mehmet , Erdogan Ali , Dogru Arzu Kocagun , Yilmaz Ismet , Yurekli Muhittin , Esrefoglu Mukaddes 
Published: May 2006

AbstractCold exposure can induce a form of environmental stress. Cold stress (CS) alters homeostasis, results in the creation of reactive oxygen species and leads to alterations in the antioxidant defense system. The caffeic acid phenethyl ester (CAPE), an active component of propolis, has an antioxidant capacity. We investigated the effect of CS on oxidative stress and antioxidant defense system and the possible protective effect of CAPE in rat liver tissue. Twenty‐four female Wistar Albino rats were divided into four groups: Control, CAPE‐treated, CS, and CAPE‐treated CS (CS + CAPE) group. Catalase (CAT), glutathione peroxidase (GSH‐Px), superoxide dismutase (SOD) activities and total glutathione (GSH) and malondialdehyde (MDA) levels were measured. In addition, histological changes in liver tissue were examined by light microscopy. SOD, CAT and GSH‐Px activities and total GSH level were significantly declined in the CS group. In the CS + CAPE group, the activities of these three enzymes and GSH level significantly raised with regard to the CS group. MDA levels increased in the CS group and decreased in the CS + CAPE group. The tissues of the CS group showed some histopathological changes such as necrosis, hepatocyte degeneration, sinusoidal dilatation, hemorrhage and vascular congestion and dilatation. In the CS + CAPE group, the histopathological evidence of hepatic damage was markedly reduced. Histological parameters were consistent with biochemical parameters. In this study, CS increased oxidative stress in liver tissue. CAPE regulated antioxidant enzymes, inhibited lipid peroxidation and reduced hepatic damage.
Key Informants' Perceptions of Health Care for Elders at the U.S.‐Mexico Border
Authors: Guo Guifang , Phillips Linda 
Published: May 2006

ABSTRACT
Objective: This study was part of a systematic assessment to gain an understanding of aging in a rural community along the U.S.‐Mexico border in Arizona.Design: It used a participatory action research design. Interviews were conducted among key informants (n=29), including health and social services providers and community leaders. Content analysis focused on identifying common themes and concerns related to elders.Results: Major themes identified were (1) social infrastructure issues, (2) community awareness of health problems, (3) socioeconomic problems, (4) cultural influences on health beliefs, practice, and use of services, (5) image of aging, (6) border issues, and (7) educational needs for service providers.Conclusion: Elders living at the border are a particularly vulnerable population with strong cultural affiliations and health disparities. Although the population of elders has been growing at the border, the traditional focus on the health care needs of youth and children has contributed to the neglect of issues facing elders. This study provided community key informants' perspective of aging to community members, policy makers, service agencies, and health care providers for community development. A conceptual framework was developed for educational programs and research projects for health professionals who care for elders at the border.
Disordered Migration of Interneurons within Focal Cortical Dysplasia
Authors: Kapur Jaideep 
Published: May 2006

Dysfunction of Synaptic Inhibition in Epilepsy Associated with Focal Cortical Dysplasia Calcagnotto ME, Paredes MF, Tihan T, Barbaro NM, Baraban SC J Neurosci 2005;25(42):9649–9657 Focal cortical dysplasia (FCD) is a common and important cause of medically intractable epilepsy. In patients with temporal lobe epilepsy and in several animal models, compromised neuronal inhibition, mediated by GABA, contributes to seizure genesis. Although reduction in GABAergic interneuron density has been reported in FCD tissue samples, there is little available information on the resulting physiological changes in synaptic inhibition and the potential contribution of these changes to epileptogenesis in the dysplastic human brain. Using visualized whole-cell patch-clamp recordings from identified neurons in tissue slices obtained from patients with FCD, we demonstrate that GABAA-receptor-mediated inhibition is substantially altered in regions of dysplasia. These alterations include a significant reduction in IPSC frequency and a potentially compensatory decrease in transporter-mediated GABA reuptake function; the latter is marked by a significant increase in the decay-time constant for evoked and spontaneous IPSCs and a lack of effect of the GABA transportinhibitor 1-[2 ([(diphenylmethylene)imino]oxy)ethyl]-1,2,5, 6-tetrahydro-3-pyridinecarboxylic acid hydrochloride on IPSC kinetics. Immunohistochemical staining revealed a scattering of GABAergic interneurons across dysplastic cortex and striking reductions in GABA transporter expression. Together, these results suggest that profound alterations in GABA-mediated synaptic inhibition play an essential role in the process of epileptogenesis in patients with FCD.
Evolution of surveillance methods for detection of bacterial contamination of platelets in a university hospital, 1991 through 2004
Authors: Yomtovian Roslyn A. , Palavecino Elizabeth L. , Dysktra Alden H. , Downes Katharine A. , Morrissey Anne M. , Bajaksouzian Saralee , Pokorny Marcella A. , Lazarus Hillard M. , Jacobs Michael R. 
Published: May 2006

BACKGROUND:  Platelet (PLT) bacterial contamination (PBC) is the most common transfusion‐associated infection. It is important to understand the impact of interventions addressing this problem.STUDY DESIGN AND METHODS:  PBC was studied by prospective (active) and transfusion‐reaction triggered (passive) surveillance from July 1991 to December 2004. Active surveillance, utilized for 10 years, included bacterial culture of all or 4‐ and 5‐day‐old PLTs at issue and intermittent use of Gram stain, pH measurements, and early (24‐hr) culture of single‐donor plateletpheresis (SDP) units.RESULTS:  Active surveillance detected 38 instances of PBC, 7 in SDP units (1:2213) and 31 in random‐donor PLT units (1:2090 units, p = 0.89; or 1:418 pools of 5 units, p < 0.001). Contaminants were coagulase‐negative staphylococci (CONS; n = 27), Staphylococcus aureus (4), Bacillus cereus (1), Serratia marcescens (2), streptococci (2 S. bovis, 1 S. uberis), and CONS with viridans group streptococcus (1). Only one instance of contamination, caused by Pseudomonas aeruginosa, was detected by passive surveillance, with fatal outcome. Colony counts of contaminants ranged from 0.5 × 102 to 4 × 1011 colony‐forming units per mL at time of issue. PBC was interdicted before transfusion in 6 cases through Gram stain screening. Transfusion reactions occurred in 13 of 32 recipients (41%), with 9 severe reactions (28%) and 3 deaths (9%). pH testing failed to detect 5 contaminated units and resulted in discard of nearly 2 percent of units, whereas culture of SDP units at 24 hours failed to identify a contaminated unit.CONCLUSION:  Improved active surveillance methods for detecting PBC are needed to improve the safety of PLT transfusions.
Suppression of Autonomic‐Mediated Triggered Firing in Pulmonary Vein Preparations, 24 Hours Postcoronary Artery Ligation in Dogs
Authors: PATTERSON EUGENE , YU XICHUN , HUANG SHIJUN , GARRETT MARION , KEM DAVID C. 
Published: May 2006

Introduction: Rapid arrhythmia originating within pulmonary veins (PVs) precipitates atrial fibrillation (AF) in man. To determine a possible basis for an increased incidence of AF observed peri‐myocardial infarction in man, we compared AF induction in vivo and triggered arrhythmia formation within isolated PVs in vitro in normal dogs and dogs studied 24 hours postcoronary artery ligation. Methods and Results: The incidence of AF initiated by atrial premature stimuli was increased in dogs postcoronary artery ligation (6/9) versus normal (2/12) (P = 0.03). In isolated PVs from normal hearts, pause‐dependent early afterdepolarizations (EADs) were enhanced by catecholamines. Rapid arrhythmia (1,182 ± 213 beats/min) was triggered during isoproterenol/norepinephrine (32 nM) + acetylcholine (100 nM) (N = 16/23) using the same pacing pauses eliciting EADs. Rapid arrhythmia (802 ± 161 beats/min) was also triggered by local autonomic nerve stimulation (ANS; N = 18/23). Despite equivalent pause‐dependent afterdepolarization formation in PVs from infarcted hearts, a rightward 45‐fold and 28‐fold shift in the dose–response curve for afterdepolarization enhancement was observed for isoproterenol and norepinephrine, respectively (P < 0.02). ANS (N = 1/19) and isoproterenol/norepinephrine (32 nM) + acetylcholine (100 nM) (N = 0/9 and 0/12, respectively) (P = 0.0001) failed to elicit arrhythmia formation. Beta‐adrenergic receptor desensitization was associated with a 2.5‐fold increase in PV beta‐adrenergic receptor kinase (ARK). Conclusion: The data demonstrate decreased susceptibility of isolated canine PVs for arrhythmia triggered by local ANS, or pacing pauses in the presence of a catecholamine + acetylcholine, postmyocardial infarction, despite a greater susceptibility of the intact heart to AF. The decreased arrhythmia susceptibility was observed coincident with an increase in beta‐ARK and a decreased responsiveness to beta‐adrenergic receptor agonists.
Comparison of efficacy of moxidectin and ivermectin in the treatment of Strongyloides fulleborni infection in rhesus macaques
Authors: Dufour Jason P. , Cogswell Frank B. , Phillippi‐Falkenstein Kathrine M. , Bohm Rudolf P. 
Published: May 2006

AbstractBackground  Strongyloides infection may result in clinical disease or confound experimental protocols that utilize non‐human primates. There is presently a Strongyloides fulleborni infection rate of approximately 27% in the Tulane National Primate Research Center's breeding colonies despite the routine therapeutic and prophylactic use of ivermectin.Methods  A study was conducted to determine if moxidectin treatment offers advantages to the intestinal parasite control program. A total of 150 rhesus macaques (Macaca mulatta) that were removed from the breeding colonies due to illness were selected for the study. The animals were randomly assigned to treatment groups with 75 receiving ivermectin and 75 receiving moxidectin. Egg counts were performed on fecal samples collected pre‐ and post‐treatment.Results  Both treatments resulted in decreases in the number of eggs/g in the post‐treatment sample as compared with the pre‐treatment sample; however, no significant difference was found between treatment groups.Conclusions  With the data demonstrating a similar efficacy in both ivermectin and moxidectin treated macaques, the benefit of moxidectin treatment relates to biosafety and topical application.
1140919448 CD200‐dependent suppression of human NK activity by IVIG requires CD200 receptor type 2
Authors: Clark DA , Banwatt D , Gorczynski R , Blajchman MA 
Published: May 2006

Problem:  IVIG prepared from plasma of stored human blood can be efficacious in improving pregnancy success in a selected subgroup of patients but RCTs using an IVIG showing inferior suppression of NK activity in vitro have been negative (J Assist Reprod Genet 2006). A significant component of NK suppression by IVIG appears to be due to CD200 released into plasma from PBL during storage at 4C. CD200 receptors (CD200R) are expressed at the fetomaternal interface prior to onset of abortion; CD200R1 mediates direct effects on gamma‐delta T cell development and suppresses alpha‐beta T cell responses in vitro, whereas CD200R2 alters DC so as to facilitate development of alpha‐beta Treg cells. Which receptor(s) mediate NK cell suppression?Methods:  Purified human PBL or the CD56+ NK cell subset of PBL were used to lyse 51Cr‐labeled K562 cells in vitro. Different IVIG preparations were tested for suppressive ability, and suppression was blocked by either anti‐huCD200 mAb or rabbit anti‐huCD200R1 or R2 antibodies.Results:  CD200‐dependent IVIG NK suppressive potency differed among IVIG types (Gammagard>Gamunex>>Gamimmune). CD200‐dependent suppression was blocked by anti‐CD200R antibody able to react with the type 2 receptor. K562 cells did not express receptor, and purified CD56+ NK cells were suppressed effectively without the need for non‐NK cells.Conclusions:  IVIG may directly express NK cell activity via CD200 binding to CD200R2.
Arterial complications of thoracic outlet syndrome
Authors: Singh Devender , Pinjala Rama Krishna , Reddy Lankala Rama Chander , Vani Venkat NagLaxmi 
Published: May 2006

Objective: Arterial vascular complications resulting from thoracic outlet compression, although rare, can be substantial and potentially limb threatening. These complications are due to compressions at the thoracic outlet, the treatment of which continues to be a dilemma. The objective of the present study was to review our experience with this problem with particular reference to its management.Methods: We performed a retrospective study of 12 years and retrieved data from the medical records department of Nizam’s Institute of Medical Sciences, Hyderabad, India. A retrospective review identified 35 patients (age range 15–50 years). In 31 patients, the vasculopathy was caused by a cervical rib, soft tissue anomalies (n = 31), and an elongated transverse process (n = 4). Evaluation included assessment with colour duplex and arteriography with positional maneuvers. Thirty‐two patients presented with a fixed pulse deficit, 22 patients had palpable mass and 15 patients had distal embolization.Results: In 31 patients with cervical rib, the rib was excised via a supraclavicular approach, Scalenectomy was performed and the arterial pathology was repaired on its merit, usually by a vein graft replacement or bypass. The elongated process was excised in the other four patients. Twelve patients required thrombectomy of the distal arteries and a bypass procedure (with a vein/prosthetic graft) was performed in 14 patients. Dorsal sympathectomy, as an adjunct, was carried out in 10 patients. In view of their advanced distal disease, four patients were given prostaglandin therapy. Short‐term follow up of 2 years showed good results.Conclusion: Our results show that simple excision of the cervical rib with scalenectomy via supraclavicular approach, together with arterial reconstruction (if required) is adequate for arterial vascular complications resulting from thoracic outlet compression. Patients with severe distal disease may require other adjunct procedures like dorsal sympathectomy or prostaglandin infusions along with proximal reconstruction.
Genetic and Biochemical Evidence for the Involvement of a Molybdenum-Dependent Enzyme in One of the Selenite Reduction Pathways ofRhodobacter sphaeroidesf. sp.denitrificansIL106
Authors: Pierru Bénédicte , Grosse Sandrine , Pignol David , Sabaty Monique 
Published: May 2006

ABSTRACTSelenite reduction inRhodobacter sphaeroidesf. sp.denitrificanswas observed under photosynthetic conditions, following a 100-h lag period. This adaptation period was suppressed if the medium was inoculated with a culture previously grown in the presence of selenite, suggesting that selenite reduction involves an inducible enzymatic pathway. A transposon library was screened to isolate mutants affected in selenite reduction. Of the eight mutants isolated, two were affected in molybdenum cofactor synthesis. ThesemoaAandmogAmutants showed an increased duration of the lag phase and a decreased rate of selenite reduction. When grown in the presence of tungstate, a well-known molybdenum-dependent enzyme (molybdoenzyme) inhibitor, the wild-type strain displayed the same phenotype. The addition of tungstate in the medium or the inactivation of the molybdocofactor synthesis induced a decrease of 40% in the rate of selenite reduction. These results suggest that several pathways are involved and that one of them involves a molybdoenzyme. Although addition of nitrate or dimethyl sulfoxide (DMSO) to the medium increased the selenite reduction activity of the culture, neither the periplasmic nitrate reductase NAP nor the DMSO reductase is the implicated molybdoenzyme, since thenapAanddmsAmutants, with expression of nitrate reductase and DMSO reductase, respectively, eliminated, were not affected by selenite reduction. A role for the biotine sulfoxide reductase, another characterized molybdoenzyme, is unlikely, since its overexpression in a defective strain did not restore the selenite reduction activity.
Manganese(II)-Oxidizing
Bacillus
Spores in Guaymas Basin Hydrothermal Sediments and Plumes
Authors: Dick Gregory J. , Lee Yifan E. , Tebo Bradley M. 
Published: May 2006

ABSTRACT

Microbial oxidation and precipitation of manganese at deep-sea hydrothermal vents are important oceanic biogeochemical processes, yet nothing is known about the types of microorganisms or mechanisms involved. Here we report isolation of a number of diverse spore-forming Mn(II)-oxidizing
Bacillus
species from Guaymas Basin, a deep-sea hydrothermal vent environment in the Gulf of California, where rapid microbially mediated Mn(II) oxidation was previously observed.
mnxG
multicopper oxidase genes involved in Mn(II) oxidation were amplified from all Mn(II)-oxidizing
Bacillus
spores isolated, suggesting that a copper-mediated mechanism of Mn(II) oxidation could be important at deep-sea hydrothermal vents. Phylogenetic analysis of 16S rRNA and
mnxG
genes revealed that while many of the deep-sea Mn(II)-oxidizing
Bacillus
species are very closely related to previously recognized isolates from coastal sediments, other organisms represent novel strains and clusters. The growth and Mn(II) oxidation properties of these
Bacillus
species suggest that in hydrothermal sediments they are likely present as spores that are active in oxidizing Mn(II) as it emerges from the seafloor.
Plasmid pCAR3 Contains Multiple Gene Sets Involved in the Conversion of Carbazole to Anthranilate
Authors: Urata Masaaki , Uchimura Hiromasa , Noguchi Haruko , Sakaguchi Tomoya , Takemura Tetsuo , Eto Kaori , Habe Hiroshi , Omori Toshio , Yamane Hisakazu , Nojiri Hideaki 
Published: May 2006

ABSTRACT

The carbazole degradative
car-I
gene cluster (
carAaIBaIBbICIAcI
) of
Sphingomonas
sp. strain KA1 is located on the 254-kb circular plasmid pCAR3. Carbazole conversion to anthranilate is catalyzed by carbazole 1,9a-dioxygenase (CARDO; CarAaIAcI),
meta
-cleavage enzyme (CarBaIBbI), and hydrolase (CarCI). CARDO is a three-component dioxygenase, and CarAaI and CarAcI are its terminal oxygenase and ferredoxin components. The
car-I
gene cluster lacks the gene encoding the ferredoxin reductase component of CARDO. In the present study, based on the draft sequence of pCAR3, we found multiple carbazole degradation genes dispersed in four loci on pCAR3, including a second copy of the
car
gene cluster (
carAaIIBaIIBbIICIIAcII
) and the ferredoxin/reductase genes
fdxI-fdrI
and
fdrII
. Biotransformation experiments showed that FdrI (or FdrII) could drive the electron transfer chain from NAD(P)H to CarAaI (or CarAaII) with the aid of ferredoxin (CarAcI, CarAcII, or FdxI). Because this electron transfer chain showed phylogenetic relatedness to that consisting of putidaredoxin and putidaredoxin reductase of the P450cam monooxygenase system of
Pseudomonas putida
, CARDO systems of KA1 can be classified in the class IIA Rieske non-heme iron oxygenase system. Reverse transcription-PCR (RT-PCR) and quantitative RT-PCR analyses revealed that two
car
gene clusters constituted operons, and their expression was induced when KA1 was exposed to carbazole, although the
fdxI-fdrI
and
fdrII
genes were expressed constitutively. Both terminal oxygenases of KA1 showed roughly the same substrate specificity as that from the well-characterized carbazole degrader
Pseudomonas resinovorans
CA10, although slight differences were observed.
Levels of Polyamines and Kinetic Characterization of Their Uptake in the Soybean Pathogen
Phytophthora sojae
Authors: Chibucos M. Constantine , Morris Paul F. 
Published: May 2006

ABSTRACT

Polyamines are ubiquitous biologically active aliphatic cations that are at least transiently available in the soil from decaying organic matter. Our objectives in this study were to characterize polyamine uptake kinetics in
Phytophthora sojae
zoospores and to quantify endogenous polyamines in hyphae, zoospores, and soybean roots. Zoospores contained 10 times more free putrescine than spermidine, while hyphae contained only 4 times as much free putrescine as spermidine. Zoospores contained no conjugated putrescine, but conjugated spermidine was present. Hyphae contained both conjugated putrescine and spermidine at levels comparable to the hyphal free putrescine and spermidine levels. In soybean roots, cadaverine was the most abundant polyamine, but only putrescine efflux was detected. The selective efflux of putrescine suggests that the regulation of polyamine availability is part of the overall plant strategy to influence microbial growth in the rhizosphere. In zoospores, uptake experiments with [1,4-
14
C]putrescine and [1,4-
14
C]spermidine confirmed the existence of high-affinity polyamine transport for both polyamines. Putrescine uptake was reduced by high levels of exogenous spermidine, but spermidine uptake was not reduced by exogenous putrescine. These observations suggest that
P. sojae
zoospores express at least two high-affinity polyamine transporters, one that is spermidine specific and a second that is putrescine specific or putrescine preferential. Disruption of polyamine uptake or metabolism has major effects on a wide range of cellular activities in other organisms and has been proposed as a potential control strategy for
Phytophthora
. Inhibition of polyamine uptake may be a means of reducing the fitness of the zoospore along with subsequent developmental stages that precede infection.