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Objectives: Taurine, a sulfur-containing amino acid, has high hydrophilicity and is poorly absorbed. Tauropyrone, a taurine-containing 1,4-dihydropyridine derivative, is suggested to have greater activity than taurine owing to improved physicochemical properties that facilitate delivery of the compound to target cells. The aim of this study was to determine whether the 1,4-dihydropyridine moiety in tauropyrone improves the pharmacological efficacy of taurine in vitro and in vivo., Methods: The effects of taurine and tauropyrone, as well as of the 1,4-dihydropyridine moiety were compared in in-vitro experiments to determine the binding to GABA receptors and influence on mitochondrial processes (isolated rat liver mitochondria), and in in-vivo tests to assess the influence on behavioural effects caused by the GABA-A receptor ligands, bicuculline, diazepam and ethanol., Key Findings: Unlike taurine, tauropyrone did not display binding activity for the GABA-A receptor, and only taurine (but not tauropyrone) at low doses (0.1, 1.0 and 10 mg/kg) antagonised the bicuculline-induced convulsion effect. Taurine and tauropyrone had no effect on diazepam myorelaxing action, and they both exerted a comparable 'anti-ethanol' effect (shortening of the ethanol-sleeping time). Taurine and tauropyrone did not influence processes of mitochondrial bioenergetics., Conclusions: The action of tauropyrone at the level of the GABA-A receptor differs qualitatively from that of taurine, probably because of its 1,4-dihydropyridine moiety, which may hinder access to the GABA-A receptor GABA site. Tauropyrone does not show improved pharmacological efficacy in in-vitro and in-vivo studies in comparison with taurine., (© 2011 The Authors. JPP © 2011 Royal Pharmaceutical Society.)

The title compound, [Au(2)Cl(2)(C(28)H(30)N(2)P(2))]·2C(4)H(8)O, was synthesized from a bidentate phosphine ligand complexed to two linear gold(I) chloride moieties. The Au(I) atom is in an almost linear coordination with a P-Au-Cl angle of 179.22 (4)°. The complex molecules reside on a twofold rotation axis.

Pulmonary aspergillosis includes one of the forms of fungal infection due to the genus Aspergillus, and has several modes of clinical presentation that depend on the immunity and comorbidities. The aim of this study was to report on the case of an immunocompetent and previously healthy patient who developed a form of chronic pulmonary aspergillosis, and to make a brief review on the subject.

Reaction of (2,4,5-trimethoxyphenyl)(2-hydroxyphenyl)methanone with ceric ammonium nitrate furnished the xanthone, 2,3-dimethoxy-9H-xanthen-9-one. Under the same conditions the related (1,4-dimethoxynaphthalen-2-yl)(2-hydroxyphenyl)methanone resulted in the formation of 12a-methoxy-5H-benzo[c]xanthenes 5,7(12aH)-dione. Other examples of this novel transformation are also outlined.

The title compound, [Au(2)Cl(2)(C(26)H(26)N(2)P(2))], is formed from a bidentate phosphine ligand complexed to two linearly coordinated gold(I) atoms. The gold(I) atoms are 3.4873 (7) Å apart. The mol-ecule exhibits a crystallographic twofold rotation axis.

Objective: To identify factors associated with patient satisfaction at least 5 years after orthodontic treatment., Materials and Methods: A total of 209 orthodontic patients were included in the study. All subjects were treated with upper and lower fixed orthodontic appliances. Dental casts (n = 627) were examined using the Peer Assessment Rating (PAR) Index pretreatment (T1), at the end of treatment (T2) and at a long-term follow-up (mean, 8.5 years; T3). At T3, a Dental Impact on Daily Living questionnaire was used to assess the long-term effects of orthodontic treatment on daily living and satisfaction with the dentition. Multiple regression analyses were used to quantify associations between patient satisfaction and changes produced by the orthodontic treatment (PAR T2-T1), posttreatment stability (PAR T3), age at the start of treatment (T1), treatment duration (T2-T1), gender, and extraction., Results: Orthodontic treatment produced a significant improvement of 94.2% in the PAR Index (T2-T1), but this change was not associated with the level of satisfaction when the patient was questioned at least 5 years after treatment. Regression analysis showed that satisfaction was significantly associated only with the long-term posttreatment PAR index (r(2) = 0.125, P < .0001). No significant association was observed with the severity of malocclusion at the beginning (PAR-T1) or end of the orthodontic treatment (PAR-T2), age at T1, the amount of time taken during orthodontic treatment, gender, or extraction., Conclusions: Over the long term, patient satisfaction is slightly associated with the stability of the orthodontic treatment regardless of the initial occlusal condition or the final result of the orthodontic treatment.

The achiral meso form of the title compound, C(18)H(38)N(2)O(4)(2+)·2Cl(-), crystallizes to form undulating layers consisting of chains linked via weak hydroxyalkyl C-H...Cl contacts. The chains are characterized by centrosymmetric hydrogen-bonded dimers generated via N-H...Cl and hydroxycycloalkyl O-H...Cl interactions. trans-N-Alkyl bridges subdivide the chains into hydrophilic segments flanked by hydrophobic cycloalkyl stacks along [001].

The synthesis and solid state structure of the amino-alcohol ligand, (1R,2R,1'S,2'S)-N,N'-bis(2-hydroxycyclopentyl)ethane-1,2-diamine (Cyp(2)en) obtained by the reaction of cyclopentene oxide with ethylenediamine, as well as its bromide, chloride, perchlorate, and nitrate salts, is reported. In all five structures, the Cyp(2)en ligand sits on a center of inversion with the two amino groups and two hydroxyl groups of the cyclopentyl moieties trans to each other across that inversion center. Comparing this conformation to that of a density functional theory (DFT)-calculated structure of cis-[Ni(Cyp(2)en)(H(2)O)(2)](2+) suggests that the ligand is not well pre-organized for coordinating a metal ion. The likely solution structure of this ligand, and that of the related ligands bis(2-hydroxy)ethane-1,2-diamine (Bheen) and bis(2-hydroxycyclohexyl)ethane-1,2-diamine (Cy(2)en), was explored using molecular mechanics modeling with the generalized AMBER force field. A Boltzmann distribution of the lowest energy conformations found shows that 36 conformations of Bheen each contribute more than 1% to the population at 300 K; this decreases to 27 conformations for Cyp(2)en and to 12 for Cy(2)en, and Cy(2)en is the most rigid of the three ligands. The population-weighted root-mean-square deviation (rmsd) between these lowest energy conformations and the conformation required for coordinating a metal ion increased in the order Cy(2)en < Cyp(2)en < Bheen, while stability constants for coordinating Ni(II) decrease in the order Cy(2)en > Bheen > Cyp(2)en. The high pre-organization of Cy(2)en is due to an intramolecular N-H....O hydrogen bond, apparently missing in the other two ligands. Pre-organization is likely to be an important, but not the only factor, that controls the value of the stability constants of these ligands with metal ions.

Self-efficacy is a temporary and influenceable characteristic, related to situations and tasks, mediating health-promoting behaviours. This study aimed to evaluate psychometric properties of a Portuguese version of the Fluid Intake Appraisal Inventory, and to describe self-efficacy in relation to limited fluid intake amongst Portuguese haemodialysis patients. Respondents were recruited from three dialysis units, and 113 of 155 eligible patients gave their informed consent. The translated scale was distributed and collected by the head nurses. Interdialytic weight gain was calculated as percentage of dry weight. Satisfactory psychometric properties were estimated in the Portuguese context. The participants' self-efficacy in relation to low fluid intake was asymmetrically distributed; the majority had moderately to high self-efficacy while some patients had very low self-efficacy to limited fluid intake. There was a significant difference in self-efficacy to fluid restrictions; patients with a weight gain of 3.5% or less presented higher self-efficacy scores than did patients exceeding the cutoff point.

The murine embryonic stem cell test (EST) represents a validated alternative method for in vivo embryotoxicity testing. In the present study, primary hepatocytes were combined with the EST by a preincubation approach to improve its predictivity on bioactivation caused teratogenicity. As substances the well-known proteratogens cyclophosphamide (CPA) and valpromide (VPD) were used. The embryotoxic potential of CPA was detected by a strong decrease of the resulting ID(50)-concentration (50% inhibition of ES cell differentiation) after incubation with murine hepatocytes. Interspecies variation in metabolism was detected by testing VPD. After incubation of VPD with murine hepatocytes no inhibition of ES cell differentiation was observed, since hardly any teratogenic VPD metabolites were formed. In contrast, with human hepatocytes a significant conversion of VPD into the teratogen valproic acid (VPA) was observed. In summary we developed a co-culture approach for embryotoxicity testing, whereby the test compounds were incubated with hepatocytes and the supernatant was added to the ES cell culture to obtain a dose dependency of the preincubated test substances., (Copyright 2010 Elsevier Inc. All rights reserved.)

The title compound, C(17)H(27)BrO(5), DEB, is a derivative of artemisinin which is used in malara therapy. The OR-group at C12 is cis to the CH(3)-group at C11 and axially oriented on ring D which has a chair conformation. The crystal packing is stabilized by several weak inter-molecular C-H⋯O inter-actions, which combine to form a C-H-O bonded network parallel to (001).

We examined how visual context information provided during encoding, and unrelated to the target word, affected later recollection for words presented alone using a remember-know paradigm. Experiments 1A and 1B showed that participants had better overall memory-specifically, recollection-for words studied with pictures of intact faces than for words studied with pictures of scrambled or inverted faces. Experiment 2 replicated these results and showed that recollection was higher for words studied with pictures of faces than when no image accompanied the study word. In Experiment 3 participants showed equivalent memory for words studied with unique faces as for those studied with a repeatedly presented face. Results suggest that recollection benefits when visual context information high in meaningful content accompanies study words and that this benefit is not related to the uniqueness of the context. We suggest that participants use elaborative processes to integrate item and meaningful contexts into ensemble information, improving subsequent item recollection.

Emerging evidence suggests that the neuroprotective effects of valproic acid (VPA) occur via inhibition of histone deacetylases (HDACs) and activation of gene expression. This study assessed the ability of four VPA derivatives to cause histone hyperacetylation and protect against glutamate-induced excitotoxicity in cultured neurons. We found that (S)-2-pentyl-4-pentynoic acid (compound III) and (+/-)-2-hexyl-4-pentynoic acid (compound V) were far more potent and robust than VPA in inducing histone hyperacetylation and protecting against glutamate excitotoxicity. Thus, the increase in histone acetylation elicited by compounds III and V was significant at 5microM and reached a maximal increase of 600-700% at 50-100microM, compared with only a 200% increase by VPA at 100microM. The neuroprotective effects of compounds III and V were evident at 10-25microM and reached a complete protection at 50-100microM, while a significant partial protection by VPA was observed at 100microM. These two compounds were also more effective than VPA in increasing HSP70-1a and HSP70-1b mRNA levels. At 50microM, compound V was most robust in increasing HSP-1a mRNA levels, followed by compound III, and then by VPA. HSP-1b mRNA was only significantly upregulated by compounds V and III, but not by VPA or other VPA derivatives under these treatment conditions. Our results suggest that these two VPA derivatives may ultimately be developed into potent neuroprotective drugs in preclinical and clinical studies., (Published by Elsevier Ireland Ltd.)

The title compound, [Ag(2)(NO(3))(2)(C(28)H(30)N(2)P(2))](n), crystallizes in polymeric α-helices. Three O atoms from three different nitrate ions in equatorial positions and two Ag atoms at axial positions set up a trigonal bipyramid. These units are linked by the phosphine ligands into endless helical chains that run along the c axis. The crystal used for the data collection was a racemic twin.

The title compound, C(28)H(30)N(2)P(2), adopts a well documented and studied gauche conformation around the hydrazine bond. Bond lengths and angles are in the typical ranges expected for P-N and P-C bonds. A normal hydrazine N-N bond length of 1.426 (3) Å is observed.

The most common cognitive complaint reported by healthy older adults and young adults with traumatic brain injury (TBI) is memory difficulties. We investigated the effects of normal aging and the long-term effects of TBI in young adults on the susceptibility to incorrectly endorse distracter information on a memory test. Prior to a study phase, participants viewed a "pre-exposure" list containing distracter words, presented once or three times, and half of the target study words. Subsequently, during the study phase, all target words were presented such that, across lists, study words were viewed either once or three times. On the recognition test, TBI and older adult participants were more likely to falsely endorse "pre-exposed" distracter words viewed three times as being from the target study list, compared to non-head-injured young controls. Normal aging and head injury in young may similarly compromise one's ability to reject highly familiar, but distracting, information during recognition. Older adult and TBI participants were also slower to complete the Trail Making task and had poorer output on a Digit Span task, suggesting these two populations share a deficit in executive function and working memory. Similar changes in frontal lobe function may underlie these shared cognitive deficits.

Ecstasy, which is used as a recreational drug, is a common street name for 3, 4-methylenedioxymethamphetamine (MDMA). Another drug of abuse chemically related, though less common than MDMA, is the amphetamine derivative 4-methylthioamphetamine (MTA). MDMA and MTA induce different systemic and organ-specific effects, including neurotoxicity, hyperthermia, nephrotoxicity, cardiotoxicity and hepatotoxicity. Therefore, it is clear that MDMA and MTA are responsible for inducing organ toxicity. The mechanisms underlying MDMA and MTA-induced hepatotoxicity are multifactorial, and therefore not completely understood. Recent findings indicate interference with cellular bioenergetics as an important toxicological feature of ecstasy. However, less is known about the involvement of mitochondria in MTA-induced hepatotoxicity. Thus, we compared the direct influence of MDMA and MTA on rat liver mitochondrial function [mitochondrial permeability transition (MPT), mitochondrial oxidative stress, and mitochondrial bioenergetics]. It was shown that MTA (from 0.025 up to 0.1mM) was more potent than MDMA (from 0.2 up to 0.5mM) in decreasing the sensitivity of rat liver mitochondria to MPT. However, higher concentrations of MTA (from 0.5 up to 2mM) were highly toxic to mitochondria. MTA simultaneously increased H(2)O(2) production in a monoamine oxidase (MAO)-dependent way, and uncoupled and inhibited mitochondrial respiration. In contrast, MDMA had only limited or no effects on these mitochondrial parameters. According to these results, it is possible to postulate that, depending on the concentration, MTA can potentially be more efficient in its effects on liver mitochondria than MDMA and, also, that its harmful effects may contribute to its hepatotoxicity., (Copyright 2010 Elsevier Ireland Ltd. All rights reserved.)

The crystal structure of the title compound, C(8)H(17)NO(2), consists of (R,R) and (S,S) enantiomeric pairs packed in adjacent double layers which are characterized by centrosymmetric hydrogen-bonded dimers, generated via N-H...O and O-H...O interactions, respectively. Intermolecular interactions, related to acceptor and donor molecule chirality, link the achiral double layers into tubular columns, which consist of a staggered hydrophilic inner core surrounded by a hydrophobic cycloalkyl outer surface and extend in the [011] direction.

Aim: To assess the long-term stability of orthodontic treatment and some factors associated to posttreatment changes., Methods: Six hundred twenty-seven dental casts of 209 patients were examined with the PAR Index at pretreatment (T1), end of treatment (T2), and at long-term follow-up (T3, mean 8.5 years posttreatment). Friedman test and multiple regression analysis at P < .05 were used to evaluate changes among the time points and factors associated with stability., Results: After orthodontic treatment, the PAR Index improved by 94.2%. No significant change was observed between T2 and T3 (P>.05). However, when the sample was divided into a well- (PAR Index ≠ 3) and a less well-finished (PAR Index >3) group, it was observed that well-finished patients experienced some deterioration (P<.001), whereas the less well-finished ones showed some improvement (P<.05). Even with the deterioration, the well-finished patients still had a better PAR Index at T3 compared to the less well-finished ones. Regression analysis showed that PAR Index at T1 and T2, age at T1, and length of retainer wear had a slight association with occlusal stability (R(2)=0.27). No significant association was observed between stability and length of treatment, length of follow-up, sex, extraction, or third molar status on the other side., Conclusion: Orthodontic treatment is quite stable. Not so well-finished treatments tend to show some improvement and well-finished ones deteriorate some. Well-finished patients still have better occlusal characteristics. Retention contributes to maintenance of the final orthodontic results., (COPYRIGHT © 2009 BY QUINTESSENCE PUBLISHING CO, INC.)

Background: Central venous oxygen saturation (ScvO(2)) is a valuable prognostic marker in sepsis. However, its value in cardiac surgery has not been assessed yet. This study aimed at evaluating ScvO(2) as a tool for predicting short-term organ dysfunction (OD) after cardiac surgery., Methods: A prospective cohort including cardiac surgery patients submitted to a goal-oriented therapy to maintain ScvO(2) above 70% was studied. Postoperative blood samples collected at 30 minutes (T1), 6 hours (T2), and 24 hours (T3) for ScvO(2) measurement were selected to further analysis. Two groups were formed according to the absence (G0) or presence (G1) of OD defined as a Sequential Organ Failure Assessment (SOFA) score >or=5 on the third postoperative day. A logistic regression analysis was performed to identify the variables independently associated with OD on the third postoperative day., Results: From the 246 patients included, 54 (22%) developed OD and were defined as G1. The mortality rates in G0 and G1 were 1.6% and 31.5%, respectively (P < .001). In the comparative analysis between G0 and G1, the ScvO(2) values were remarkably lower in G1 at T1 (66.2 +/- 9.2 vs 62.3 +/- 11.6; P = .009), T2 (69.6 +/- 5.9 vs 63.5 +/- 9.4; P

The neural correlates of recollection were examined using event-related functional MRI. We examined how the presence of different visual context information during encoding of target words influenced later recollection for the words presented alone at retrieval. Participants studied words presented with different pictures of faces or scrambled faces on each trial, and on a subsequent scanned recognition test made 'remember', 'know' or 'new' responses to words presented alone. Prior to the study phase, participants performed a localizer task, in which the fusiform face area (FFA) was identified. We compared brain activation patterns for remember and know responses given to words studied with faces as compared to scrambled faces. Though behaviourally participants showed no difference in memory performance depending on encoding trial type, both a group- and individual-based region-of-interest analysis showed increased activation in the functionally-defined FFA for remember responses given to words studied with faces compared to scrambled faces. A regression analysis additionally showed that activation in the right fusiform gyrus increased as the relative recollection benefit for words studied with meaningful (face) compared to non-meaningful (scrambled face) context information increased. Results suggest that context-specific brain regions implicated during encoding are recruited during retrieval, and that the degree to which participants activate context-specific brain regions during retrieval is related to a behavioural benefit in later recollection for target information presented alone.

The crystal structure of the nitrate salt of N,N'-bis(2-hydroxyethyl)-ethane-1,2-diamine (BHEEN), and its complex with Zn(II) and Cd(II) are reported. (H(2)BHEEN)(NO(3))(2) packs in a layered structure with a herringbone pattern within each layer arising from H-bonding between amino and alcohol protons and NO(3)(-) counterions. In [Zn(BHEEN)(2)]Cl(2), each ligand coordinates to Zn(II) through its two N-donors producing a distorted tetrahedral geometry at the metal centre. The two hydroxyethyl arms of each ligand are trans to each other and the crystals obtained contained a racemic mixture of the bis-trans-R,R and the bis-trans-S,S isomers. All four hydroxyl groups are H-bonded to chloride counter ions, creating a layered structure. Whilst distant from the metal ion (average 3.00 A), the four O atoms of the pendent hydroxylamino groups appear positioned to interact with the metal. The orientation of the arms is preserved in a B3LYP gas phase calculation of the structure. An analysis using Bader's Atoms in Molecules indicates that the Zn-N bonds are predominantly ionic with some covalent character and that there is a weak interaction between the metal and the hydroxyl groups. Several other weak interactions including four O...HN, five O...HC and a H-H dihydrogen bond were identified. The Cd(II) complex of BHEEN crystallised as a dimer [(mu-Cl)(2)(Cd(BHEEN)Cl)(2))] with two asymmetrically-bound bridging Cl(-) ligands and a terminally-coordinated Cl(-) on each metal ion. One hydroxyl group of each ligand is coordinated to the metal and the uncoordinated hydroxyl group is H-bonded to the H atom of the coordinated hydroxyl group of the second ligand in the complex. The ESI-MS spectrum shows the presence of di-cadmium complexes, but the most intense peaks are due to mono-cadmium complexes. The gas phase B3LYP structure of the dimer energy-minimises into two monomers and the longer bond between Cd(II) and bridging Cl(-) breaks. Hence, dimerisation may be a consequence of the crystallisation process and the dimer may not be the predominant species in solution.

Metolachlor is one of the most intensively used chloroacetamide herbicides. However, its effects on the environment and on non-target animals and humans as well as its interference at a cell/molecular level have not yet been fully elucidated. The aim of this study was: firstly, to evaluate the potential toxicity of metolachlor at a cell/subcellular level by using two in vitro biological model systems (a strain of Bacillus stearothermophilus and rat liver mitochondria); secondly, to evaluate the relative sensibility of these models to xenobiotics to reinforce their suitability for pollutant toxicity assessment. Our results show that metolachlor inhibits growth and impairs the respiratory activity of B.stearothermophilus at concentrations two to three orders of magnitude higher than those at which bacterial cells are affected by other pesticides. Also at concentrations significantly higher than those of other pesticides, metolachlor depressed the respiratory control ratio, membrane potential and respiration of rat liver mitochondria when malate/glutamate or succinate were used as respiratory substrates. Moreover, metolachlor impaired the respiratory activity of rat liver mitochondria in the same concentration range at which it inhibited bacterial respiratory system (0.4-5.0 micromol/mg of protein). In conclusion, the high concentration range at which metolachlor induces toxicity in vitro suggests that this compound is safer than other pesticides previously studied in our laboratory, using the same model systems. The good parallelism between metolachlor effects on both models and the toxicity data described in the literature, together with results obtained in our laboratory with other compounds, indicate the suitability of these systems to assess toxicity in vitro.

The title compound, C(7)H(13)NO, forms R(2)(2)(8) N-H...O hydrogen-bonded dimers and C4 N-H...O-linked chains, which are further stabilized by a C-H...O interaction. The combination of these interactions results in a hydrogen-bonded network parallel to (100), with a motif that can be described by the secondary graph set R(4)(6)(16). The existence of the same hydrogen-bonding motif in 1-phenylcyclopentanecarboxamide and 1-(2-bromophenyl)cyclohexanecarboxamide [Lemmerer & Michael (2008). CrystEngComm, 10, 95-102 indicates that replacing the H atom on position 1 with a more bulky group does not necessarily disrupt the observed hydrogen-bonding pattern. The presence of a C-H...O interaction to stabilize the R(4)(6)(16) network does, however, seem to be required. In addition, the title compound is isomorphous with a previously published structure of cyclopentanecarboxamide [Winter et al. (1981). Acta Cryst. B37, 2183-2185].

It is increasingly recognised that mitochondria are potential targets to pharmacological and toxicological actions of membrane-active agents, including some 1,4-dihydropyridines derivatives (DHPs). The 5-acetyl(carbamoyl)-6-methylsulfanyl-1,4-dihydropyridine-5-carbonitriles (OSI-1146, OSI-3701, OSI-3761, and OSI-9642) is a new group of DHPs with minor differences on the molecular structure. It has also been shown that OSI-1146 displays cardiovascular, antioxidant, and antiradical activities, whereas OSI-3701 and OSI-3761 display hepatoprotective activity. Due to their protective properties, this group of DHPs may be potentially useful for the treatment of several pathological processes, including those associated with oxidative stress. However, the cellular targets for their pharmacological actions have not been investigated. The presented study, using isolated rat liver mitochondria was designed to investigate if mitochondria are a cellular target for the pharmacological and/or toxicological actions of these new group of DHPs. We studied the direct influence of these DHPs on rat liver mitochondrial function [bioenergetics, membrane permeability transition (MPT), and oxidative stress]. It was shown that OSI-1146, OSI-3761, and OSI-9642, in the concentration range of up to 200 microM, interfered with mitochondrial bioenergetics by affecting complexes I and II of the mitochondrial respiratory chain, the ATPase activity, and mitochondrial inner membrane permeability to protons. However, the effects of OSI-1146 were higher than those of OSI-3761 and OSI-9642. The remaining compound, OSI-3701, had no effect on the bioenergetic parameters tested. All the compounds increased the susceptibility of mitochondria to MPT, but, OSI-3701, not affecting the bioenergetic parameters, was the most potent. Moreover, all the compounds protected mitochondria against lipid peroxidation induced by the oxidant pair ADP/Fe(2+), but OSI-1146 was also the most potent. In conclusion, our results indicate that mitochondria are the potential intracellular targets for both protective and toxicological actions of the DHP compounds studied, suggesting that the potential use of these compounds as therapeutic agents should carefully consider their toxic effects to mitochondria.

The structures of two distinct polymorphic forms of N-(2,6-difluorophenyl)formamide, C(7)H(5)F(2)NO, have been studied using single crystals obtained under different crystallizing conditions. The two forms crystallize in different space groups, viz. form (Ia) in the orthorhombic Pbca and form (Ib) in the monoclinic P2(1) space group. Each polymorph crystallizes with one complete molecule in the asymmetric unit and they have a similar molecular geometry, showing a trans conformation with the formamide group being out of the plane of the aromatic ring. The packing arrangements of the two polymorphs are quite different, with form (Ia) having molecules that are stacked in an alternating arrangement, linked into chains of N-H...O hydrogen bonds along the crystallographic a direction, while form (Ib) has its N-H...O hydrogen-bonded molecules stacked in a linear fashion. A theoretical study of the two structures allows information to be gained regarding other contributing interactions, such as pi-pi and weak C-H...F, in their crystal structures.

Objectives: Determine the impact of an oral health education program on oral hygiene and the awareness level of elementary schoolchildren., Methods: A total sample of 247 schoolchildren between the ages of 7 and 15 years from the public school system of Parnamirim, Brazil, were selected and randomly allocated to a control (n=115) and experimental (n=132) group. Sociodemographic data were recorded and a clinical examination was given to establish the decayed, missing and filled surfaces index (DMFS) and the dmfs index. The visible plaque index (VPI) and gingival bleeding index (GBI) were collected before and after the intervention. A closed-question questionnaire was applied to the schoolchildren before and after intervention to determine their knowledge of oral health. The experimental group took part in oral health education activities over a 4-month period., Results: The VPI (P = 0.014; CI 0.24-0.86) and GBI (P = 0.013; CI 0.28-0.87) of the experimental group were significantly lower after educational activities. Similarly, the experimental group also obtained a higher number of correct answers on the questionnaire (P < 0.0001; CI 3.73-26.81). However, there was no association between oral hygiene indicators, VPI (P = 0.311; CI 0.23-1.60), and GBI (P = 0.927; CI 0.43-2.16), and the information level of the schoolchildren., Conclusions: Contextualized educational activities in the school routine had positive effects on oral hygiene and the level of information about oral health, although the more informed individuals did not always practice better oral hygiene.

We examined how context presented at study affects recollection of words in younger and older adults. In Experiment 1, participants studied words presented with a picture of a face (context-rich condition) or a rectangle (context-weak condition), and subsequently made 'Remember', 'Know', or 'New' judgments to words presented alone. Younger, but not older, adults showed higher Remember accuracy following rich- than weak-context trials. In Experiment 2, we manipulated the type of processing engaged during the encoding of context-word pairs. Younger and older adults studied words presented with a picture of a face under a surface feature (gender) or binding feature (match) instruction condition. Both age groups showed higher Remember accuracy in the binding than surface instruction condition. Results suggest that providing rich contextual detail at encoding boosts later item recollection in younger adults. Older adults, however, do not spontaneously engage in the processes required to boost recollection, though instructional manipulation during encoding lessens this deficit.

Purposes: To determine the incidence of retinopathy of prematurity and assess the main risk factors involved in its development., Methods: Retrospective cohort study carried out from January 2004 to December 2006, at University Hospital Onofre Lopes, Natal (RN)-Brazil. The sample was composed of 663 newborns, with less than or equal to 36 weeks of gestational age and/or birth weight less than or equal to 1,500 g, submitted to the protocol of retinopathy of prematurity in the ophthalmology department of the hospital. The variables were: gender, birth weight, gestational age, duration of oxygen therapy, mechanical ventilation, sepsis and blood transfusion. Data were analyzed through the chi-squared test, Fisher's exact test and logistic regression model., Results: Of the 663 cases, retinopathy of prematurity occurred in 414 (62.4%). Of the total sample, 338 (51.0%) were male and 282 (42.5%) female. Mean and standard deviation of weight, gestational age and duration of oxygen therapy were, respectively, 1,334.9+/-345.6 g, 31.9+/-2.3 weeks and 10.0+/-14.0 days. The incidence of retinopathy in premature newborns in the period was 62.4%, 58.0% of cases in 2004, 67.2% in 2005 and 63.0% in 2006. The multiple logistic regression analysis showed that the weight less than 1,000 g (p<0.001; adjOR=17.18, CI=6.52-45.29) and between 1,000 g and 1,500 g (p=0.002; adjOR -4.20 CI=1.68-10.48), the time of oxygen lounger than 20 days (p=0.022; adjOR=3.40, CI=1.19-9.69) and blood transfusion (p=0.022; adjOR -2.06, CI=1.11-3.83) are independent factors for the disease., Conclusions: The study showed a high incidence of the disease in the service. A low birth weight, a prolonged oxygen therapy and blood transfusion are factors associated with the development of retinopathy of prematurity. Gestational age is not a reliable parameter for screening of newborns in the service.

Cisplatin (CisPt) is the most important platinum anticancer drug widely used in the treatment of head, neck, ovarian and testicular cancers. However, the mechanisms by which CisPt induces cytotoxicity, namely hepatotoxicity, are not completely understood. The goal of this study was to investigate the influence of CisPt on rat liver mitochondrial functions (Ca(2+)-induced mitochondrial permeability transition (MPT), mitochondrial bioenergetics, and mitochondrial oxidative stress) to better understand the mechanism underlying its hepatotoxicity. The effect of thiol group protecting agents and some antioxidants against CisPt-induced mitochondrial damage was also investigated. Treatment of rat liver mitochondria with CisPt (20nmol/mg protein) induced Ca(2+)-dependent mitochondrial swelling, depolarization of membrane potential (DeltaPsi), Ca(2+) release, and NAD(P)H fluorescence intensity decay. These effects were prevented by cyclosporine A (CyA), a potent and specific inhibitor of the MPT. In the concentration range of up to 40nmol/mg protein, CisPt slightly inhibited state 3 and stimulated state 2 and state 4 respiration rates using succinate as respiratory substrate. The respiratory indexes, respiratory control ratio (RCR) and ADP/O ratios, the DeltaPsi, and the ADP phosphorylation rate were also depressed. CisPt induced mitochondrial inner membrane permeabilization to protons (proton leak) but did not induce significant changes on mitochondrial H(2)O(2) generation. All the effects induced by CisPt on rat liver mitochondria were prevented by thiol group protecting agents namely, glutathione (GSH), dithiothreitol (DTT), N-acetyl-L-cysteine (NAC) and cysteine (CYS), whereas superoxide-dismutase (SOD), catalase (CAT) and ascorbate (ASC) were without effect. In conclusion, the anticancer drug CisPt: (1) increases the sensitivity of mitochondria to Ca(2+)-induced MPT; (2) interferes with mitochondrial bioenergetics by increasing mitochondrial inner membrane permeabilization to H(+); (3) does not significantly affect H(2)O(2) generation by mitochondria; (4) its mitochondrial damaging effects are protected by thiol group protecting agents. Based on these conclusions, it is possible to hypothesise that small changes on the redox-status of thiol groups, affecting membrane permeability to cations (Ca(2+) and H(+)) underlie CisPt-induced liver mitochondrial damage, putatively responsible for its hepatotoxicity. Therefore, we propose that CisPt-induced mitochondrial damage and consequent hepatotoxicity could be prevented by using thiol group protecting agents as therapeutic adjuvants.

In the crystal structure of the title compound, C(7)H(5)Br(2)NO, molecules related by translation are linked through N-H...O hydrogen bonds to form chains in the crystallographic a direction, with the aryl rings stacked parallel to each other along the chain. Besides the N-H...O hydrogen bonds, Br...O and Br...Br intermolecular interactions complete the packing of molecules in the crystal structure.

The authors investigated the effect of divided attention, study-list repetition, and age on recollection and familiarity. Older and younger adults under full attention and younger adults under divided attention at study viewed word lists highly associated with a single unstudied word (critical lure) once or three times, and subsequently performed a remember-know recognition test. Younger adults made fewer false remember responses to critical lures from repeated study lists, whereas younger adults under divided attention and older adults both showed an increase with repetition. Findings suggest older adults' susceptibility to illusory memories is related to a deficit in available attention during encoding.

Objective: This prospective study aimed at investigating predictive factors for compensatory sweating after thoracoscopic sympathectomy., Methods: From 2000 to 2002, 80 patients (53 females and 27 males) underwent thoracoscopic sympathectomy to treat hyperhidrosis. Patient ages ranged from 12 to 56 years, and the mean post-operative follow-up period was 42.51 +/- 5.98 months. Patient satisfaction with the results was evaluated through the use of a rating scale. The procedure was performed bilaterally: at the T2 level for facial hyperhidrosis; at the T3-T4 level for axillary hyperhidrosis; and at the T3 level for palmar hyperhidrosis., Results: Post-operatively, 68 patients (85.0%) presented compensatory sweating, which was classified as mild in 23 (33.8%), moderate in 23 (33.8%) and severe in 22 (32.4%). Considering the final surgical results, 70 patients (87.5%) were satisfied with the outcome of the operation, whereas 10 patients (12.5%) were dissatisfied. The level of patient satisfaction varied according to gender, age, body mass index (BMI) and extent of denervation. The compensatory sweating was more severe on the abdomen and back than on the legs., Conclusions: Although compensatory sweating, which is a common adverse effect of sympathectomy, occurred in the majority of cases, the level of patient satisfaction was high. The best candidates for thoracoscopic sympathectomy are young adult women with a BMI < 24.9 kg/m(2).

Chronic non-communicable diseases represent a major public health problem, requiring more effective investigation and control by government agencies. The aim of this study was to correlate the mortality rate for oral cancer in Brazilian State capitals from 1998 to 2002 with socioeconomic factors collected in the 2000 census, using an ecological study design. Data were obtained from the Mortality Information System from 1998 to 2002. Social factors were taken from the Brazilian Human Development Atlases. After data collection, statistical analysis was performed using Pearson's correlation index. The findings included positive and significant correlations among the socioeconomic indicators (Municipal Human Development Index-- MHDI, MHDI-income, MHDI-education, MHDI-life expectancy, and per capita income), and negative and significant correlations with the socioeconomic indicators Gini Index and infant mortality. Despite the study's limitations and probable underreporting in less developed State capitals, the study found significant statistic correlations between the selected socioeconomic indicators and the oral cancer mortality rate.

We used a multivariate analysis technique, partial least squares (PLS), to identify distributed patterns of brain activity associated with retrieval effort and retrieval success. Participants performed a recognition memory task under full attention (FA) or two different divided attention (DA) conditions during retrieval. Behaviorally, recognition was disrupted when a word, but not digit-based distracting task, was performed concurrently with retrieval. PLS was used to identify patterns of brain activation that together covaried with the three memory conditions and which were functionally connected with activity in the right hippocampus to produce successful memory performance. Results indicate that activity in the right dorsolateral frontal cortex increases during conditions of DA at retrieval, and that successful memory performance in the DA-digit condition is associated with activation of the same network of brain regions functionally connected to the right hippocampus, as under FA, which increases with increasing memory performance. Finally, DA conditions that disrupt successful memory performance (DA-word) interfere with recruitment of both retrieval-effort and retrieval-success networks.

The aim of this study was to investigate the prevalence of orofacial clefts in live newborns from 1998 to 2002 in Brazilian state capitals and correlate their occurrence with a number of relevant socioeconomic factors collected in the 2000 census. Data was obtained from the Public Health Hospital Information System (SIH-SUS), Information System of Live Hospital Births (SINASC) and Atlases of Human Development in Brazil. The results showed that the mean prevalence of orofacial clefts in Brazil was 0.36 per 1,000 live births. Using Pearson's correlation coefficient, the correlation between cleft rate and social factors was not statistically significant (p > 0.05). Our study suggests that there is no correlation between the municipal economic factors and the prevalence of orofacial clefts, which is likely influenced by underrecording problems in the less developed municipalities.

Purpose: The objective of the present study was to assess the persistence of non-nutritive sucking habits and its relationship with breastfeeding, as well as to establish the influence of sociodemographic factors on these habits among children aged 3 to 5 years., Materials and Methods: A case-control study was conducted with 1107 children from public and private daycare centres in Natal, Brazil: 450 in the case group (312 pacifier suckers and 138 thumb suckers) and 657 in the control group (habit-free). Data regarding sociodemographic conditions and duration of breastfeeding were obtained using a structured questionnaire., Results: Breastfeeding for a duration of > 6 months (adjusted odds ratio = 0.311; 95% confidence interval = 0.226 to 0.428) was an independent protective factor against persistent pacifier sucking. The use of pacifiers was more frequent among 3-year-old children and among those from a higher income family and a higher level of schooling of parents. The relation between duration of breastfeeding and thumb sucking was not statistically significant (P = 0.087). There was an association between the thumb sucking habit with sex (female), low level of schooling of father and the child being born as the last male child in the birth order. No relation was found between breastfeeding and habit frequency (day/night and night) (P = 0.301). An association with habit frequency was found with the age of 3 years, female, the family income group that ranged between US $176 and US $875, and those attending private institutions., Conclusions: Breastfeeding for a duration of > 6 months was a protective factor against the persistence of pacifier sucking, but the subjectivity of the mother-child relationship must be investigated further.

Children with Down syndrome exhibit 2 related hematopoietic diseases: transient myeloproliferative disorder (TMD) and acute megakaryoblastic leukemia (AMKL). Both exhibit clonal expansion of blasts with biphenotypic erythroid and megakaryocytic features and contain somatic GATA1 mutations. While altered GATA1 inhibits erythro-megakaryocytic development, less is known about how trisomy 21 impacts blood formation, particularly in the human fetus where TMD and AMKL originate. We used in vitro and mouse transplantation assays to study hematopoiesis in trisomy 21 fetal livers with normal GATA1 alleles. Remarkably, trisomy 21 progenitors exhibited enhanced production of erythroid and megakaryocytic cells that proliferated excessively. Our findings indicate that trisomy 21 itself is associated with cell-autonomous expansion of erythro-megakaryocytic progenitors. This may predispose to TMD and AMKL by increasing the pool of cells susceptible to malignant transformation through acquired mutations in GATA1 and other cooperating genes.

The complexes trans-[Rh(X)(XNC)(PPh 3) 2] (X = Cl, 1; Br, 2; SC 6F 5, 3; C 2Ph, 4; XNC = xylyl isocyanide) combine reversibly with molecular oxygen to give [Rh(X)(O 2)(XNC)(PPh 3) 2] of which [Rh(SC 6F 5)(O 2)(XNC)(PPh 3) 2] ( 7) and [Rh(C 2Ph)(O 2)(XNC)(PPh 3) 2] ( 8) are sufficiently stable to be isolated in crystalline form. Complexes 2, 3, 4, and 7 have been structurally characterized. Kinetic data for the dissociation of O 2 from the dioxygen adducts of 1- 4 were obtained using (31)P NMR to monitor changes in the concentration of [Rh(X)(O 2)(XNC)(PPh 3) 2] (X = Cl, Br, SC 6F 5, C 2Ph) resulting from the bubbling of argon through the respective warmed solutions (solvent chlorobenzene). From data recorded at temperatures in the range 30-70 degrees C, activation parameters were obtained as follows: Delta H (++) (kJ mol (-1)): 31.7 +/- 1.6 (X = Cl), 52.1 +/- 4.3 (X = Br), 66.0 +/- 5.8 (X = SC 6F 5), 101.3 +/- 1.8 (X = C 2Ph); Delta S (++) (J K (-1) mol (-1)): -170.3 +/- 5.0 (X = Cl), -120 +/- 13.6 (X = Br), -89 +/- 18.2 (X = SC 6F 5), -6.4 +/- 5.4 (X = C 2Ph). The values of Delta H (++) and Delta S (++) are closely correlated (R (2) = 0.9997), consistent with a common dissociation pathway along which the rate-determining step occurs at a different position for each X. Relative magnitudes of Delta H (++) are interpreted in terms of differing polarizabilities of ligands X.

The authors examined how divided attention (DA) and aging affect memory, and the use of organizational strategies, during retrieval. Younger and older adults studied a list of either unrelated or categorizable words presented auditorily under full attention, and later recalled them under full attention or DA condition with a word- or digit-monitoring distracting task. The magnitude of memory interference did not interact with age during retrieval of unrelated words. During retrieval of categorizable words, older adults suffered significantly greater memory interference than young in both DA conditions. The number of categories recalled was significantly reduced by the word- but not digit-based distracting task, and this effect did not differ across age groups. The number of words recalled per category was reduced in both DA conditions, in both age groups. Semantic clustering, corrected for total recall score, was reduced in older but not younger adults, in both DA conditions. Findings suggest that older adults cannot make use of strategies, to the same extent as do young, to boost memory for categorized words under DA conditions, leading to amplified memory interference.

Professional practices reflect the structuring of health services and are related to the underlying principles of the prevailing health care model. This study focused on preventive and educational practices by dentists in the Family Health Program in Natal, Rio Grande do Norte State, Brazil. A structured interview was held with 80 dentists, in addition to analysis of documents from the Outpatient Database of the Unified National Health System (SIA-SUS) and the Primary Care Database. Individual activities involving orientation for oral hygiene and topical application of fluoride were reported by 87.5% and 95% of dentists, respectively. At the collective level, all the dentists that worked in schools (91.2%) performed topical fluoride application, while 86.2% conducted educational activities. According to SIA-SUS records, preventive activities accounted for 41% of all procedures. Among these, topical application of fluoride gel per sitting and supervised brushing accounted for 24.4% and 31%, respectively. As for educational activities, 57.4% were held in the health care unit and 42.6% in the community. The findings indicate that the preventive practices focus on dental caries, particularly in schoolchildren, and that they need to be expanded to include other oral health problems.

Previously mildronate, an aza-butyrobetaine derivative, was shown to be a cytoprotective drug, through its mechanism of action of inhibition of carnitine palmitoyltransferase-1, thus protecting mitochondria from long-chain fatty acid accumulation and subsequent damage. Recently in an azidothymidine (AZT)-induced cardiotoxicity model in vivo (in mice), we have found mildronate's ability of protecting heart tissue from nuclear factor kappaB abnormal expression. Preliminary data also demonstrate cerebro- and hepatoprotecting properties of mildronate in AZT-toxicity models. We suggest that mildronate may target its action predominantly to mitochondria. The present study in isolated rat liver mitochondria was designed to clarify mitochondrial targets for mildronate by using AZT as a model compound. The aim of this study was to investigate: (1) whether mildronate may protect mitochondria from AZT-induced toxicity; and (2) which is the most critical target in mitochondrial processes that is responsible for mildronate's regulatory action. The results showed that mildronate protected mitochondria from AZT-induced damage predominantly at the level of complex I, mainly by reducing hydrogen peroxide generation. Significant protection of AZT-caused inhibition of uncoupled respiration, ADP to oxygen ratio, and transmembrane potential were also observed. Mildronate per se had no effect on the bioenergetics, oxidative stress, or permeability transition of rat liver mitochondria. Since mitochondrial complex I is the first enzyme of the respiratory electron transport chain and its damage is considered to be responsible for different mitochondrial diseases, we may account for mildronate's effectiveness in the prevention of pathologies associated with mitochondrial dysfunctions.

Five novel epoxide derivatives of cytochalasin B were synthesized. Reaction of cytochalasin B with t-BHP and BuLi led to selective epoxidation of the C-21/22 double bond to give a single monoepoxide, while reaction with m-CPBA yielded two diepoxides. Reaction of the monoepoxide with m-CPBA yielded two triepoxides. The relative configurations of the epoxides were elucidated by analogy with the natural product by means of spectroscopic methods; full assignment of NMR signals was achieved, and the absolute configuration was confirmed by X-ray crystallography., (Copyright (c) 2008 John Wiley & Sons, Ltd.)

The 1,4-dihydropyridines OSI-1210, OSI-1211 (etaftoron), and OSI-3802 are compounds with similar chemical structure. They differ by the length of the alkoxyl chain in positions 3 and 5 of the dihydropyridine (DHP) ring and by their pharmacological action characteristics. However, as far as we know, a clear relationship between the effects of these compounds and the length of the alkoxyl chain in positions 3 and 5 of the DHP has not been established. The goal of this study was to compare the influence of OSI-1210, OSI-1211 (etaftoron), and OSI-3802 on rat liver mitochondrial bioenergetics and on the physical properties of membrane lipid bilayers, correlating their actions with the length of the alkoxyl chain in positions 3 and 5 of the DHP ring. Using either glutamate/malate or succinate as respiratory substrates, all the compounds, in concentrations of up to 500 microM, depressed state 3 and uncoupled respiration, respiratory control (RCR) and ADP/O ratios, and phosphorylation rate, whereas state 4 respiration was stimulated. However, the stimulatory effect on state 4 induced by OSI-3802, the compound with the longest chain in positions 3 and 5 of the DHP ring, as well as its inhibitory effects on RCR and ADP/O ratios and phosphorylation rate were more pronounced than that induced by OSI-1210 and OSI-1211 (etaftoron), the compounds with the shortest and intermediate chains, respectively. Moreover, OSI-3802 maximized state 4 stimulation and minimized RCR and ADP/O ratios, and phosphorylation rate at a concentration of 100 microM, whereas low graduate effects were detected with OSI-1210 and OSI-1211 (etaftoron) for concentrations of up to 500 microM. At low concentrations (< or =30 microM), OSI-3802, like its analogue OSI-1212 (cerebrocrast), reduced the phase transition temperature, the cooperative unit size, and the enthalpy associated with the phase transition temperature of dimyristoylphosphatidylcholine (DMPC) membrane bilayers. A good correlation was established between the effects of 200 microM OSI-1210, OSI-1211 (etaftoron), and OSI-3802 on glutamate/malate- and succinate-dependent RCR of rat liver mitochondria and on the enthalpy change (Delta H) for the thermotropic profile of DMPC membrane bilayers at a 0.2 drug/DMPC molar ratio, indicating that the changes induced by these compounds on both mitochondrial membrane integrity and physical properties of DMPC membrane bilayers are strongly related to the length of the alkoxyl chain in positions 3 and 5 of the DHP ring. A putative relationship between membrane physical perturbation, bioenergetics impairment and the molecular characteristics of the compounds will be established as an approach to better understand their differentiated toxicological and pharmacological actions.

Background: Quality indicators (QI) for cardiac surgery are important instruments for measuring healthcare quality in hospital centers and allow comparison with high-quality healthcare centers., Objective: To evaluate QIs in isolated myocardial revascularization procedures (CABG) performed at a tertiary cardiology center., Methods: One hundred and forty-four consecutive patients who had undergone isolated CABG were evaluated between October 2005 and March 2007. One hundred and eight patients were men (75%), the mean age was 65+/-11, and the EuroSCORE was 4+/-3. The following QIs were measured: time elapsed between the surgery date-setting appointment and the actual day of the CABG (TDC); surgery cancellation rate (SCR) due to problems in hospital infrastructure; length of hospital stay (LOS); operative mortality (OM) and rate of readmission (RHR) for infection in the surgical wound., Results: The TDC (n=98) was 4+/-3 days (median: 4 days) and the SCR was zero. The OM recorded of 4.9% (95% confidence interval [CI] = 2.2 - 9.87%) was lower than the expected OM of 5.1% (95% CI = 1.4% to 14.37%), but with no statistical significance (p=0.65). The area under the ROC curve of the EuroSCORE for the OM was 0.702 (95% CI = 0.485 - 0.919). LOS was 11+/-9 days. The area under the ROC curve of the EuroSCORE for the LOS was 0.764 (95% CI = 0.675 - 0.852). The RHR recorded was 2.1%., Conclusion: The measurement of the QIs showed that, in a medical center with a low annual volume of CABG, the results were compatible with the risk profile of the population involved.

The title compound, C(16)H(22)N(4)P(2), crystallizes about a centre of symmetry, leading to a chair conformation of the heterocyclic ring as is commonly found for this type of compound.

N-Phenylformamide, C(7)H(7)NO, crystallizes with two molecules in the asymmetric unit which have different conformations of the formylamino group, one being cis and the other trans. This is the first example of an arylformamide crystal containing both conformational isomers and it may thus be considered a cocrystal of the two conformers. The two molecules in the unit cell are linked through N-H...O hydrogen bonding to two other molecules, thereby forming hydrogen-bonded tetramers within the crystal structure.

Some studies have suggested that older adults remember more positive than negative valence information, relative to younger adults, whereas other studies have reported no such difference. We tested whether differences in encoding instructions and in personal relevance could account for these inconsistencies. Younger and older adults were instructed either to passively view positive, negative, and neutral pictures or to actively categorize them by valence. On a subsequent incidental recall test, older adults recalled equal numbers of positive and negative pictures, whereas younger adults recalled negative pictures best. There was no effect of encoding instructions. Crucially, when the pictures were grouped into high and low personal relevance, a positivity bias emerged in older adults only for low-relevance pictures, suggesting that the personal relevance of pictures may be the factor underlying cross-study differences.

Sildenafil citrate (Viagra) is a potent and specific inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5), which exhibits cardioprotective action against ischemia/reperfusion injury in intact and isolated heart. The mechanism of its cardioprotective action is not completely understood, but some results suggested that sildenafil exerts cardioprotection through the opening of mitochondrial ATP-sensitive K+ channels (mitoKATP). However, the impact of sildenafil citrate per se on isolated heart mitochondrial function is unknown. The goal of this study was to investigate the influence of the compound on mitochondrial function (bioenergetics, Ca2+-induced mitochondrial permeability transition, and hydrogen peroxide (H2O2) generation) in an attempt to correlate its known actions with effects on heart mitochondria. It was observed that sildenafil citrate concentrations of up to 50 muM did not significantly affect glutamate/malate-supported respiration in states 2, 3, 4, oligomycin-inhibited state 3, and uncoupled respiration. The respiratory control ratio (RCR), the ADP to oxygen ratio (ADP/O), the transmembrane potential (DeltaPsi), the phosphorylation rate, and the membrane permeability to H+, K+ and Ca2+ were not affected either. However, sildenafil citrate decreased H2O2 generation by mitochondria respiring glutamate/malate, and also decreased the formation of superoxide radical (O2 (*-) ) generated in a hypoxantine/xantine oxidase system. It was concluded that sildenafil citrate concentrations of up to 50 microM do not affect either rat heart mitochondrial bioenergetics or Ca2+-induced mitochondrial permeability transition, but it depresses H2O2 generation by acting as a superoxide dismutase (SOD)-mimetic. By preventing reactive oxygen species (ROS) generation, sildenafil citrate may preserve heart mitochondrial function.

A Remember-Know paradigm was used to examine the cognitive resource requirements of recollection and familiarity memory processes at retrieval. Younger and older adults studied a list of words, and in a later auditory recognition test indicated whether each word was Remembered, Known, or New. Retrieval was performed under full or divided attention (DA) conditions, with either a digit task to numbers, or an animacy task to words, presented visually. Younger and older adults showed an increase in false Remember responses during both DA conditions, indicating a general effect of attention on illusory recollection. Both age groups also showed decreased accuracy in Know responses, but only during the word-based DA condition, indicating a material-specific effect on familiarity. Aging was associated with decreased accuracy in Remember, but not Know, responses, and with increased latency in distracting task responses under DA conditions. Results suggest that avoiding false recollective responses during retrieval requires attentional resources, whereas accurate familiarity responses require the reactivation of content-specific representations.