Crystal structure of the novel PaiA N-acetyltransferase from Thermoplasma acidophilum involved in the negative control of sporulation and degradative enzyme production.

GCN5-related N-acetyltransferases (GNATs) are the most widely distributed acetyltransferase systems among all three domains of life. GNATs appear to be involved in several key processes, including microbial antibiotic resistance, compacting eukaryotic DNA, controlling gene expression, and protein synthesis. Here, we report the crystal structure of a putative GNAT Ta0374 from Thermoplasma acidophilum, a hyperacidophilic bacterium, that has been determined in an apo-form, in complex with its natural ligand (acetyl coenzyme A), and in complex with a product of reaction (coenzyme A) obtained by cocrystallization with spermidine. Sequence and structural analysis reveals that Ta0374 belongs to a novel protein family, PaiA, involved in the negative control of sporulation and degradative enzyme production. The crystal structure of Ta0374 confirms that it binds acetyl coenzyme A in a way similar to other GNATs and is capable of acetylating spermidine. Based on structural and docking analysis, it is expected that Glu53 and Tyr93 are key residues for recognizing spermidine. Additionally, we find that the purification His-Tag in the apo-form structure of Ta0374 prevents binding of acetyl coenzyme A in the crystal, though not in solution, and affects a chain-flip rotation of "motif A" which is the most conserved sequence among canonical acetyltransferases.

An assessment of the footprint and carrying capacity of oil and gas well sites: The implications for limiting hydrocarbon reserves.

We estimate the likely physical footprint of well pads if shale gas or oil developments were to go forward in Europe and used these estimates to understand their impact upon existing infrastructure (e.g. roads, buildings), the carrying capacity of the environment, and how the proportion of extractable resources maybe limited. Using visual imagery, we calculate the average conventional well site footprints to be 10,800m2 in the UK, 44,600m2 in The Netherlands and 3000m2 in Poland. The average area per well is 541m2/well in the UK, 6370m2/well in The Netherlands, and 2870m2/well in Poland. Average access road lengths are 230m in the UK, 310m in The Netherlands and 250m in Poland. To assess the carrying capacity of the land surface, well pads of the average footprint, with recommended setbacks, were placed randomly into the licensed blocks covering the Bowland Shale, UK. The extent to which they interacted or disrupted existing infrastructure was then assessed. For the UK, the direct footprint would have a 33% probability of interacting with immovable infrastructure, but this would rise to 73% if a 152m setback was used, and 91% for a 609m setback. The minimum setbacks from a currently producing well in the UK were calculated to be 21m and 46m from a non-residential and residential property respectively, with mean setbacks of 329m and 447m, respectively. When the surface and sub-surface footprints were considered, the carrying capacity within the licensed blocks was between 5 and 42%, with a mean of 26%. Using previously predicted technically recoverable reserves of 8.5×1011m3 for the Bowland Basin and a recovery factor of 26%, the likely maximum accessible gas reserves would be limited by the surface carrying capacity to 2.21×1011m3.

The potential for spills and leaks of contaminated liquids from shale gas developments.

Rapid growth of hydraulic fracturing for shale gas within the USA and the possibility of shale developments within Europe has created public concern about the risks of spills and leaks associated with the industry. Reports from the Texas Railroad Commission (1999 to 2015) and the Colorado Oil and Gas Commission (2009 to 2015) were used to examine spill rates from oil and gas well pads. Pollution incident records for England and road transport incident data for the UK were examined as an analogue for potential offsite spills associated with transport for a developing shale industry. The Texas and Colorado spill data shows that the spill rate on the well pads has increased over the recorded time period. The most common spill cause was equipment failure. Within Colorado 33% of the spills recorded were found during well pad remediation and random site inspections. Based on data from the Texas Railroad Commission, a UK shale industry developing well pads with 10 lateral wells would likely experience a spill for every 16 well pads developed. The same well pad development scenario is estimated to require at least 2856 tanker movements over two years per well pad. Considering this tanker movement estimate with incident and spill frequency data from UK milk tankers, a UK shale industry would likely experience an incident on the road for every 12 well pads developed and a road spill for every 19 well pads developed. Consequently, should a UK shale industry be developed it is important that appropriate mitigation strategies are in place to minimise the risk of spills associated with well pad activities and fluid transportation movements.

Contribution of acute kidney injury toward morbidity and mortality in burns: a contemporary analysis.

BACKGROUND: Severe acute kidney injury (AKI) that requires dialytic support, a relatively uncommon complication in severely burned adults, is associated with a substantially increased mortality rate. It is not known whether milder forms of AKI have prognostic importance in burns. METHODS: We performed an observational cohort analysis of consecutive patients with major burns admitted to the burn care unit of a tertiary-care center from 1998 to 2003. Our main outcome measures were AKI stratified by the Risk of renal dysfunction, Injury to the kidney, Failure of kidney function, Loss of kidney function, and End-stage kidney disease (RIFLE) classification and mortality. RESULTS: AKI occurred in 81 of 304 patients (26.6%) with burns on 10% or greater total-body surface area. Risk factors for AKI on multivariate analysis were inhalational injury, catheter infection, and sepsis. Patients with AKI stratified by using the RIFLE classification had greater mortality, greater requirement of artificial ventilation, and longer durations of intensive care unit and hospital stays. Mortality was not significantly different among those with the "Risk" and "Injury" strata of RIFLE AKI compared with those without AKI, but mortality increased significantly with the "Failure" (60%) strata. In multivariate analysis, age, greater total-body surface area, inhalational injury, and the RIFLE classification of Failure were each independent predictors of death. CONCLUSION: In conclusion, the mortality of patients with burns with severe AKI remains high and unchanged in the modern era of critical care medicine. The RIFLE classification added prognostic information regarding morbidity in patients with milder forms of AKI.

Crystal structure and novel recognition motif of rho ADP-ribosylating C3 exoenzyme from Clostridium botulinum: structural insights for recognition specificity and catalysis.

Clostridium botulinum C3 exoenzyme inactivates the small GTP-binding protein family Rho by ADP-ribosylating asparagine 41, which depolymerizes the actin cytoskeleton. C3 thus represents a major family of the bacterial toxins that transfer the ADP-ribose moiety of NAD to specific amino acids in acceptor proteins to modify key biological activities in eukaryotic cells, including protein synthesis, differentiation, transformation, and intracellular signaling. The 1.7 A resolution C3 exoenzyme structure establishes the conserved features of the core NAD-binding beta-sandwich fold with other ADP-ribosylating toxins despite little sequence conservation. Importantly, the central core of the C3 exoenzyme structure is distinguished by the absence of an active site loop observed in many other ADP-ribosylating toxins. Unlike the ADP-ribosylating toxins that possess the active site loop near the central core, the C3 exoenzyme replaces the active site loop with an alpha-helix, alpha3. Moreover, structural and sequence similarities with the catalytic domain of vegetative insecticidal protein 2 (VIP2), an actin ADP-ribosyltransferase, unexpectedly implicates two adjacent, protruding turns, which join beta5 and beta6 of the toxin core fold, as a novel recognition specificity motif for this newly defined toxin family. Turn 1 evidently positions the solvent-exposed, aromatic side-chain of Phe209 to interact with the hydrophobic region of Rho adjacent to its GTP-binding site. Turn 2 evidently both places the Gln212 side-chain for hydrogen bonding to recognize Rho Asn41 for nucleophilic attack on the anomeric carbon of NAD ribose and holds the key Glu214 catalytic side-chain in the adjacent catalytic pocket. This proposed bipartite ADP-ribosylating toxin turn-turn (ARTT) motif places the VIP2 and C3 toxin classes into a single ARTT family characterized by analogous target protein recognition via turn 1 aromatic and turn 2 hydrogen-bonding side-chain moieties. Turn 2 centrally anchors the catalytic Glu214 within the ARTT motif, and furthermore distinguishes the C3 toxin class by a conserved turn 2 Gln and the VIP2 binary toxin class by a conserved turn 2 Glu for appropriate target side-chain hydrogen-bonding recognition. Taken together, these structural results provide a molecular basis for understanding the coupled activity and recognition specificity for C3 and for the newly defined ARTT toxin family, which acts in the depolymerization of the actin cytoskeleton. This beta5 to beta6 region of the toxin fold represents an experimentally testable and potentially general recognition motif region for other ADP-ribosylating toxins that have a similar beta-structure framework.

Structure and mechanism of the RuvB Holliday junction branch migration motor.

The RuvB hexamer is the chemomechanical motor of the RuvAB complex that migrates Holliday junction branch-points in DNA recombination and the rescue of stalled DNA replication forks. The 1.6 A crystal structure of Thermotoga maritima RuvB together with five mutant structures reveal that RuvB is an ATPase-associated with diverse cellular activities (AAA+-class ATPase) with a winged-helix DNA-binding domain. The RuvB-ADP complex structure and mutagenesis suggest how AAA+-class ATPases couple nucleotide binding and hydrolysis to interdomain conformational changes and asymmetry within the RuvB hexamer implied by the crystallographic packing and small-angle X-ray scattering in solution. ATP-driven domain motion is positioned to move double-stranded DNA through the hexamer and drive conformational changes between subunits by altering the complementary hydrophilic protein- protein interfaces. Structural and biochemical analysis of five motifs in the protein suggest that ATP binding is a strained conformation recognized both by sensors and the Walker motifs and that intersubunit activation occurs by an arginine finger motif reminiscent of the GTPase-activating proteins. Taken together, these results provide insights into how RuvB functions as a motor for branch migration of Holliday junctions.

Somatized psychiatric disorder presenting as palpitations.

BACKGROUND: Psychiatric disorder is underdiagnosed in primary care practice, often because it is somatized and the patient reports only physical symptoms. Palpitations are among the symptoms that often are somatized. METHODS: We studied prospectively 125 consecutive medical outpatients referred for ambulatory electrocardiographic monitoring to evaluate a chief complaint of palpitations. They completed an in-person research interview at the time of monitoring and a telephone follow-up interview 3 months later. The referring physicians completed questionnaires about their patients before receiving the results of the monitoring and again 3 months later. RESULTS: Forty-three patients had clinically significant cardiac arrhythmias. Twenty-four (29%) of the remaining 82 patients had a current psychiatric disorder, and 20 of these patients (83%) had major depression or panic disorder. These patients were significantly younger and more disabled, somatized more, and had more hypochondriacal concerns about their health than did patients who had no psychiatric disorder. Their palpitations were more likely to last longer than 15 minutes, were accompanied by more ancillary symptoms, and were described as more intense. At 3-month follow-up, about 90% of the patients in both groups continued to experience palpitations. Symptoms of somatization, hypochondriacal concerns, and impairment of intermediate activities had improved in both groups, but remained higher in patients with psychiatric disorder than in patients without psychiatric disorder. During the follow-up interval, patients with psychiatric disorder had more emergency department visits. The physicians of patients with psychiatric disorder were more likely to ascribe the palpitations to anxiety or depression, and ordered fewer laboratory tests on them, but few patients who had not already been in psychiatric treatment were referred or started on psychotropic medication. CONCLUSIONS: Physicians are aware of a psychiatric component to the clinical presentation of palpitation, but this observation does not result in psychiatric treatment or referral in most cases.

Liver fatty acids and the sudden infant death syndrome.

Fatty acid analyses were performed on samples of liver from 325 human infants less than 1 yr old, 275 of whom had died of sudden infant death syndrome (SIDS), and 50 of other causes (non-SIDS). Data for fatty acid composition were analyzed in relation to cause of death, age of infant, liver biotin, liver metals, and other variables by a variety of statistical methods. There were significant differences in the levels of liver fatty acids between SIDS and non-SIDS infants in the age group 1 to 6 months, notably in that the fatty acids of the SIDS infants appeared to have lower levels of dihomo-gamma-linolenic acid, which is the precursor of the "1-series" prostaglandins. Statistically significant relationships were observed between various fatty acids, and there were also significant relationships involving docosapentaenoic acid and infant age, and docosahexaenoic acid and liver iron content.

Mother rats bar-press for pups: effects of lesions of the mpoa and limbic sites on maternal behavior and operant responding for pup-reinforcement.

This series of studies explored the operant response rates for pup-reinforcement of female Sprague Dawley rats that were either postpartum or cycling and sustained lesions of the medial preoptic area (mpoa), the lateral amygdala, the nucleus accumbens, or sham lesions. The last experiment tested the effects on operant responding of preventing direct access to pups in mpoa and sham-lesioned postpartum mothers. All animals were trained prior to mating on an FR-1 bar-press schedule to criterion (50 presses in 30 min) for a food (Froot Loops) reward in an operant chamber. At the end of pregnancy animals that were to be tested postpartum were provided in their home cages with six newborn foster pups; mother-litter interactions were observed on the last 3 days of pregnancy and throughout the postpartum period. On each of these same days after a period of separation from pups, females were tested in the operant box for delivery of rat pups. With each bar-press response, a rat pup rather than a Fruit Loop was delivered down a gentle shoot into the hopper. Non-postpartum, but maternal, multiparous animals who were showing estrous cycles were tested using the same procedures. The first and second studies showed that animals (both postpartum and as cycling multiparous animals) with mpoa lesions exhibited a significant reduction in bar-press rate for pup reinforcement in the operant box. In postpartum animals, amygdala lesions also produced a bar-press deficit, whereas nucleus accumbens lesions did not. All lesioned groups showed deficits in maternal responding in the home cage and deficits in retrieval in the operant box. These results indicate that systems associated with the mpoa mediate both the stereotypical maternal behaviors and pup-reinforcement. In contrast, the expression of home cage maternal behavior is dependent on the integrity of both the amygdala and nucleus accumbens, whereas operant responding need not be. These results indicate a dissociation of mechanisms mediating expression of the species-typical maternal behavior and pup-reinforcement.

Mother rats bar-press for pups: effects of lesions of the mpoa and limbic sites on maternal behavior and operant responding for pup-reinforcement.

This series of studies explored the operant response rates for pup-reinforcement of female Sprague Dawley rats that were either postpartum or cycling and sustained lesions of the medial preoptic area (mpoa), the lateral amygdala, the nucleus accumbens, or sham lesions. The last experiment tested the effects on operant responding of preventing direct access to pups in mpoa and sham-lesioned postpartum mothers. All animals were trained prior to mating on an FR-1 bar-press schedule to criterion (50 presses in 30 min) for a food (Froot Loops) reward in an operant chamber. At the end of pregnancy animals that were to be tested postpartum were provided in their home cages with six newborn foster pups; mother-litter interactions were observed on the last 3 days of pregnancy and throughout the postpartum period. On each of these same days after a period of separation from pups, females were tested in the operant box for delivery of rat pups. With each bar-press response, a rat pup rather than a Fruit Loop was delivered down a gentle shoot into the hopper. Non-postpartum, but maternal, multiparous animals who were showing estrous cycles were tested using the same procedures. The first and second studies showed that animals (both postpartum and as cycling multiparous animals) with mpoa lesions exhibited a significant reduction in bar-press rate for pup reinforcement in the operant box. In postpartum animals, amygdala lesions also produced a bar-press deficit, whereas nucleus accumbens lesions did not. All lesioned groups showed deficits in maternal responding in the home cage and deficits in retrieval in the operant box. These results indicate that systems associated with the mpoa mediate both the stereotypical maternal behaviors and pup-reinforcement. In contrast, the expression of home cage maternal behavior is dependent on the integrity of both the amygdala and nucleus accumbens, whereas operant responding need not be. These results indicate a dissociation of mechanisms mediating expression of the species-typical maternal behavior and pup-reinforcement.

Effectiveness of behavioral therapy for chronic low back pain: a component analysis.

The effects of outpatient group behavioral therapy including aerobic exercise (BE), behavioral therapy only (B), and aerobic exercise only (E) on pain and physical and psychosocial disability were evaluated and compared in a group of mildly disabled chronic low-back-pain patients. Ninety-six Ss were randomly assigned to the 3 treatments and a waiting-list control (WL) condition and assessed on a variety of patient self-report, spouse-rated, and direct observational measures at pretreatment, posttreatment, and 6- and 12-month follow-ups. Patients in the BE condition, but not the B or E conditions, improved significantly more pretreatment to posttreatment than did WL patients on the patient self-report and observer-rated measures. At both follow-ups, all 3 treatment groups remained significantly improved from pretreatment, with no significant differences among treatments.

Personality profiles, dissociation, and absorption in women reporting repressed, recovered, or continuous memories of childhood sexual abuse.

Women reporting either repressed, recovered, or continuous memories of childhood sexual abuse or no abuse history completed questionnaires tapping personality traits, absorption (fantasy proneness), dissociation, depression, and posttraumatic stress. Planned contrasts indicated that recovered memory participants scored higher on absorption and dissociation than did those reporting either continuous memories or no abuse history; repressed memory participants scored nonsignificantly higher than did recovered memory participants. On measures of distress, continuous memory participants were indistinguishable from nonabused participants, repressed memory participants scored highest, and recovered memory participants scored midway between continuous and repressed memory participants.

Directed forgetting of trauma cues in adults reporting repressed or recovered memories of childhood sexual abuse.

An item-cuing directed forgetting task was used to investigate whether women reporting repressed (n = 13) or recovered (n = 13) memories of childhood sexual abuse (CSA) exhibit an avoidant encoding style (and resultant impaired memory) for trauma cues relative to women reporting no CSA experience (n = 15). All participants viewed intermixed trauma (e.g., molested), positive (e.g., confident), and categorized neutral (e.g., mailbox) words on a computer screen and were instructed either to remember or to forget each word. The results provided no support for the hypothesis that people reporting either repressed or recovered memories of CSA are especially adept at forgetting words related to trauma. These groups recalled words they were instructed to remember more often than words they were instructed to forget regardless of whether they were trauma related.

Cognitive processing of trauma cues in adults reporting repressed, recovered, or continuous memories of childhood sexual abuse.

Psychologically traumatized people exhibit delayed color naming of trauma words in the emotional Stroop task. Four groups of participants were asked to color name positive words, neutral words, and trauma words; these groups included 15 women who believed that they harbored repressed memories of childhood sexual abuse (CSA), 13 women who reported recovered memories of CSA, 15 women who had never forgotten their CSA, and 12 women who had never been abused. Repressed-memory participants exhibited patterns of interference indistinguishable from those of the nonabused control group participants. Irrespective of group membership, the severity of self-reported posttraumatic stress disorder symptoms was the only significant predictor of trauma-related interference, r(48) = .30, p < .05.

Directed forgetting of trauma cues in adult survivors of childhood sexual abuse with and without posttraumatic stress disorder.

The authors used a directed-forgetting task to investigate whether psychiatrically impaired adult survivors of childhood sexual abuse exhibit an avoidant encoding style and impaired memory for trauma cues. The authors tested women with abuse histories, either with or without posttraumatic stress disorder (PTSD), and women with neither abuse histories nor PTSD. The women saw intermixed trauma words (e.g., molested), positive words (e.g., confident), and categorized neutral words (e.g., mailbox) on a computer screen and were instructed either to remember or to forget each word. Relative to the other groups, the PTSD group did not exhibit recall deficits for trauma-related to-be-remembered words, nor did they recall fewer trauma-related to-be-forgotten words than other words. Instead, they exhibited recall deficits for positive and neutral words they were supposed to remember. These data are inconsistent with the hypothesis that impaired survivors exhibit avoidant encoding and impaired memory for traumatic information.

Identity, self, and personality: II. Glimpses through the autophotographic eye.

Subjects were 201 college students, who used R. C. Ziller's (1990) autophotographic method to answer the question who are you? Richness of self-depiction (i.e., creative and self-expressive vs. prosaic photo essays) and interpersonal connectedness of the self were examined. As expected, Openness to Experience from the 5-factor model predicted richness of photo essays. Among women, Neuroticism and Introversion also predicted richness. As expected, Extraversion and Agreeableness related to interpersonal orientations in photo essays. Intergenerational photos had especially salient meaning for personality. Three other predictions received support, bearing on such identity-relevant categories as alcohol use, religiosity, self-exhibition in bathing attire, and identification with one's school. Results are integrated with literature on interpersonal connectedness and the relation of creativity to personality.

The differential utility of the Minnesota Multiphasic Personality Inventory. A predictor of outcome in lumbar laminectomy for disc herniation versus spinal stenosis.

One hundred six patients with disc herniation who underwent lumbar laminectomy and discectomy and 51 patients with spinal stenosis who underwent decompressive lumbar laminectomy were evaluated for surgical outcome at least 1 year postoperatively (mean: 18 months). All had completed the Minnesota Multiphasic Personality Inventory (MMPI) as part of the preoperative evaluation. The Hypochondriasis (Hs), Depression (D), Hysteria (Hy), Psychopathic Deviate (Pd), Psychasthenia (Pt), and Schizophrenia (Sc) scales were found to be predictive of surgical outcome in the herniation group. However, no MMPI scale was related to outcome in the stenosis group. Analysis of covariance showed this fact to be related to the differences in age between the two groups of patients, rather than a result of the differing diagnoses. The MMPI appears to be more useful in predicting surgical outcome in the young and middle-aged adult patient population with disc herniation and is not of predictive utility in the older stenosis population.

Using film librarians to increase productivity.

This article presents an approach to increasing the efficiency and productivity of radiology departments by having film librarians review, select and place films on multiviewers prior to the radiologist's interpretation.

The flux of radionuclides in flowback fluid from shale gas exploitation.

This study considers the flux of radioactivity in flowback fluid from shale gas development in three areas: the Carboniferous, Bowland Shale, UK; the Silurian Shale, Poland; and the Carboniferous Barnett Shale, USA. The radioactive flux from these basins was estimated, given estimates of the number of wells developed or to be developed, the flowback volume per well and the concentration of K (potassium) and Ra (radium) in the flowback water. For comparative purposes, the range of concentration was itself considered within four scenarios for the concentration range of radioactive measured in each shale gas basin, the groundwater of the each shale gas basin, global groundwater and local surface water. The study found that (i) for the Barnett Shale and the Silurian Shale, Poland, the 1 % exceedance flux in flowback water was between seven and eight times that would be expected from local groundwater. However, for the Bowland Shale, UK, the 1 % exceedance flux (the flux that would only be expected to be exceeded 1 % of the time, i.e. a reasonable worst case scenario) in flowback water was 500 times that expected from local groundwater. (ii) In no scenario was the 1 % exceedance exposure greater than 1 mSv-the allowable annual exposure allowed for in the UK. (iii) The radioactive flux of per energy produced was lower for shale gas than for conventional oil and gas production, nuclear power production and electricity generated through burning coal.