bluuebunny/crossref_metadata_2025 huggingface dataset:
Irrigated Shiraz vines (Vitis vinifera) upregulate gas exchange and maintain berry growth in response to short spells of high maximum temperature in the field
Authors: Soar Chris J. , Collins Marisa J. , Sadras Victor O.
Published: September 2009

We tested the hypotheses that (i) a short period of high maximum temperature disrupts gas exchange and arrests berry growth and sugar accumulation in irrigated Shiraz vines (Vitis vinifera L.), and (ii) the magnitude of these effects depend on the phenological window when stress occur. Using a system combining passive heating (greenhouse effect) and active cooling (fans) to control daytime temperature, we compared vines heated to a nominal maximum of 40°C for three consecutive days and untreated controls. Maximum air temperature in heated treatments was 7.3°C (2006–07) and 6.5°C (2007–08) above ambient. Heat episodes were aligned with the beginning of a weekly irrigation cycle and applied in one of four phenological windows, namely post-fruit set, pre-veraison, veraison and pre-harvest. Heating systems did not affect relative humidity, hence vapour pressure deficit (VPD) was increased in the heated treatments and tracked the daily cycle of temperature. Heat did not affect the dynamics of berry growth and sugar accumulation, except for a 16% reduction in berry size and sugar content in vines heated shortly after fruit set in 2006–07. Vines upregulated stomatal conductance and gas exchange in response to heat. Stomatal conductance, photosynthesis and transpiration at a common VPD were consistently higher in heated vines than in controls. We suggest that stomatal behaviour previously described as part of Shiraz anisohydric syndrome may be adaptive in terms of heat tolerance at the expense of short-term transpiration efficiency.
Starch-to-sugar conversion in wood parenchyma of field-growing Laurus nobilis plants: a component of the signal pathway for embolism repair?
Authors: Salleo Sebastiano , Trifilò Patrizia , Esposito Sara , Nardini Andrea , Lo Gullo Maria A.
Published: September 2009

The ability of stems of Laurus nobilis (L.) to refill embolised xylem conduits was studied in plants both at optimal water supply (W) and under conditions of soil drought inducing xylem pressures (Px) of –1.54 (S1) and –2.35 MPa (S2). Starch depolymerisation in wood parenchyma was measured as percentage of cells ‘with high starch content’ (HSC-cells) counted under a microscope. HSC-cells decreased during embolism and increased again in refilled stems. A direct relationship was found between percentage of HSC-cells and Px, with HSC-cells between 65 and 75% of the total at Px ≥ –0.6 MPa, at which recovery from PLC was recorded. At low transpiration, starch re-appeared in wood parenchyma cells but only in plants that showed diurnal stomatal opening (W- and S1-plants). In S2-plants showing diurnal stomatal closure and nocturnal opening with Px between –1.2 to –2.4 MPa, HSC-cells were only 25% and plants did not recover from PLC. This finding suggests that (i) the Px threshold for embolism repair was ≥ –0.6 MPa, and (ii) impeded phloem loading limits starch content in wood parenchyma and embolism repair. We conclude that starch depolymerisation acts as a signal to phloem unloading sugars to embolised conduits thus generating the necessary osmotic gradients driving refilling.
Intramembrane proteolytic cleavage of a membrane-tethered transcription factor by a metalloprotease depends on ATP
Authors: Zhou Ruanbao , Cusumano Christina , Sui Dexin , Garavito R. Michael , Kroos Lee
Published: September 2009

Regulated intramembrane proteolysis (RIP) involves cleavage of a transmembrane segment of a protein. RIP governs diverse processes in a wide variety of organisms and is carried out by different types of intramembrane proteases (IPs), including a large family of metalloproteases. The
Bacillus subtilis
SpoIVFB protein is a putative metalloprotease that cleaves membrane-tethered Pro-σ
K
, releasing σ
K
to direct transcription of genes necessary for spore formation. By attaching an extra transmembrane segment to the N terminus of SpoIVFB, expression in
E. coli
was improved more than 100-fold, facilitating purification and demonstration of metalloprotease activity, which accurately cleaved purified Pro-σ
K
. Uniquely for IPs examined so far, SpoIVFB activity requires ATP, which binds to the C-terminal cystathionine-β-synthase (CBS) domain of SpoIVFB. Deleting just 10 residues from the C-terminal end of SpoIVFB nearly eliminated cleavage of coexpressed Pro-σ
K
in
E. coli
. The CBS domain of SpoIVFB was shown to interact with Pro-σ
K
and ATP changed the interaction, suggesting that ATP regulates substrate access to the active site and renders cleavage sensitive to the cellular energy level, which may be a general feature of CBS-domain-containing IPs. Incorporation of SpoIVFB into preformed liposomes stimulated its ability to cleave Pro-σ
K
. Cleavage depended on ATP and the correct peptide bond was shown to be cleaved using a rapid and sensitive mass spectrometry assay. A system for biochemical studies of RIP by a metalloprotease in a membrane environment has been established using methods that might be applicable to other IPs.
Structure of the C-terminus of the mRNA export factor Dbp5 reveals the interaction surface for the ATPase activator Gle1
Authors: Dossani Zain Y. , Weirich Christine S. , Erzberger Jan P. , Berger James M. , Weis Karsten
Published: September 2009

The DExD/H-box RNA-dependent ATPase Dbp5 plays an essential role in the nuclear export of mRNA. Dbp5 localizes to the nuclear pore complex, where its ATPase activity is stimulated by Gle1 and its coactivator inositol hexakisphosphate. Here, we present the crystal structure of the C-terminal domain of Dbp5, refined to 1.8 Å. The structure reveals a RecA-like fold that contains two defining characteristics not present in other structurally characterized DExD/H-box proteins: a C-terminal α-helix and a loop connecting β5 and α4, both of which are composed of conserved and unique elements in the Dbp5 primary sequence. Using structure-guided mutagenesis, we have identified several charged surface residues that, when mutated, weaken the binding of Gle1 and inhibit the ability of Gle1 to stimulate Dbp5's ATPase activity. In vivo analysis of the same mutations reveals that those mutants displaying the weakest ATPase stimulation in vitro are also unable to support yeast growth. Analysis of the correlation between the in vitro and in vivo data indicates that a threshold level of Dbp5 ATPase activity is required for cellular mRNA export that is not met by the unstimulated enzyme, suggesting a possible mechanism by which Dbp5's activity can be modulated to regulate mRNA export.
DISC1
splice variants are upregulated in schizophrenia and associated with risk polymorphisms
Authors: Nakata Kenji , Lipska Barbara K. , Hyde Thomas M. , Ye Tianzhang , Newburn Erin N. , Morita Yukitaka , Vakkalanka Radhakrishna , Barenboim Maxim , Sei Yoshitatsu , Weinberger Daniel R. , Kleinman Joel E.
Published: September 2009

Disrupted-In-Schizophrenia-1 (
DISC1
) is a promising susceptibility gene for major mental illness, but the mechanism of the clinical association is unknown. We searched for
DISC1
transcripts in adult and fetal human brain and tested whether their expression is altered in patients with schizophrenia and is associated with genetic variation in
DISC1
. Many alternatively spliced transcripts were identified, including groups lacking exon 3 (Δ3), exons 7 and 8 (Δ7Δ8), an exon 3 insertion variant (extra short variant-1, Esv1), and intergenic splicing between
TSNAX
and
DISC1
. Isoforms Δ7Δ8, Esv1, and Δ3, which encode truncated DISC1 proteins, were expressed more abundantly during fetal development than during postnatal ages, and their expression was higher in the hippocampus of patients with schizophrenia. Schizophrenia risk-associated polymorphisms [non-synonymous SNPs rs821616 (Cys704Ser) and rs6675281 (Leu607Phe), and rs821597] were associated with the expression of Δ3 and Δ7Δ8. Moreover, the same allele at rs6675281, which predicted higher expression of these transcripts in the hippocampus, was associated with higher expression of
DISC1
Δ7Δ8 in lymphoblasts in an independent sample. Our results implicate a molecular mechanism of genetic risk associated with
DISC1
involving specific alterations in gene processing.
Crystallographic snapshots of iterative substrate translocations during nicotianamine synthesis in archaea
Authors: Dreyfus Cyril , Lemaire David , Mari Stéphane , Pignol David , Arnoux Pascal
Published: September 2009

Nicotianamine (NA), a small molecule ubiquitous in plants, is an important divalent metal chelator and the main precursor of phytosiderophores. Nicotianamine synthase (NAS) is the enzyme catalyzing NA synthesis by the condensation of three aminopropyl moieties of S-adenosylmethionine (SAM) and the cyclization of one of them to form an azetidine ring. Here we report five crystal structures of an archaeal NAS from
Methanothermobacter thermautotrophicus
, either free or in complex with its product(s) and substrate(s). These structures reveal a two-domains fold arrangement of MtNAS, a small molecule related to NA (named here thermoNicotianamine or tNA), and an original mechanism of synthesis in a buried reaction chamber. This reaction chamber is open to the solvent through a small inlet, and a single active site allows the selective entrance of only one substrate at a time that is then processed and translocated stepwise.
Functional requirement of AgRP and NPY neurons in ovarian cycle-dependent regulation of food intake
Authors: Olofsson Louise E. , Pierce Andrew A. , Xu Allison W.
Published: September 2009

In female mammals including rodents and humans, feeding decreases during the periovulatory period of the ovarian cycle, which coincides with a surge in circulating estrogen levels. Ovariectomy increases food intake, which can be normalized by estrogen treatment at a dose and frequency mimicking those during the estrous cycle. Furthermore, administration of estrogen to rodents potently inhibits food intake. Despite these well-known effects of estrogen, neuronal subtypes that mediate estrogen's anorexigenic effects have not been identified. In this study, we show that changes in hypothalamic expression of agouti-related protein (
Agrp
) and neuropeptide Y (
Npy
) coincide with the cyclic changes in feeding across the estrous cycle. These cyclic changes in feeding are abolished in mice with degenerated AgRP neurons even though these mice cycle normally. Central administration of 17β-estradiol (E2) decreases food intake in controls but not in mice lacking the AgRP neurons. Furthermore, E2 treatment suppresses fasting-induced c-Fos activation in AgRP and NPY neurons and blunts the refeeding response. Surprisingly, although estrogen receptor alpha (ERα) is the key mediator of estrogen's anorexigenic effects, we find that expression of ERα is completely excluded from AgRP and NPY neurons in the mouse hypothalamus, suggesting that estrogen may regulate these neurons indirectly via presynaptic neurons that express ERα. This study indicates that neurons coexpressing AgRP and NPY are functionally required for the cyclic changes in feeding across estrous cycle and that AgRP and NPY neurons are essential mediators of estrogen's anorexigenic function.
Stability of body-centered cubic iron–magnesium alloys in the Earth's inner core
Authors: Kádas Krisztina , Vitos Levente , Johansson Börje , Ahuja Rajeev
Published: September 2009

The composition and the structure of the Earth's solid inner core are still unknown. Iron is accepted to be the main component of the core. Lately, the body-centered cubic (bcc) phase of iron was suggested to be present in the inner core, although its stability at core conditions is still in discussion. The higher density of pure iron compared with that of the Earth's core indicates the presence of light element(s) in this region, which could be responsible for the stability of the bcc phase. However, so far, none of the proposed composition models were in full agreement with seismic observations. The solubility of magnesium in hexagonal Fe has been found to increase significantly with increasing pressure, suggesting that Mg can also be an important element in the core. Here, we report a first-principles density functional study of bcc Fe–Mg alloys at core pressures and temperatures. We show that at core conditions, 5–10 atomic percent Mg stabilizes the bcc Fe both dynamically and thermodynamically. Our calculated density, elastic moduli, and sound velocities of bcc Fe–Mg alloys are consistent with those obtained from seismology, indicating that the bcc-structured Fe–Mg alloy is a possible model for the Earth's inner core.
Polar firn air reveals large-scale impact of anthropogenic mercury emissions during the 1970s
Authors: Faïn Xavier , Ferrari Christophe P. , Dommergue Aurélien , Albert Mary R. , Battle Mark , Severinghaus Jeff , Arnaud Laurent , Barnola Jean-Marc , Cairns Warren , Barbante Carlo , Boutron Claude
Published: September 2009

Mercury (Hg) is an extremely toxic pollutant, and its biogeochemical cycle has been perturbed by anthropogenic emissions during recent centuries. In the atmosphere, gaseous elemental mercury (GEM; Hg°) is the predominant form of mercury (up to 95%). Here we report the evolution of atmospheric levels of GEM in mid- to high-northern latitudes inferred from the interstitial air of firn (perennial snowpack) at Summit, Greenland. GEM concentrations increased rapidly after World War II from ≈1.5 ng m
−3
reaching a maximum of ≈3 ng m
−3
around 1970 and decreased until stabilizing at ≈1.7 ng m
−3
around 1995. This reconstruction reproduces real-time measurements available from the Arctic since 1995 and exhibits the same general trend observed in Europe since 1990. Anthropogenic emissions caused a two-fold rise in boreal atmospheric GEM concentrations before the 1970s, which likely contributed to higher deposition of mercury in both industrialized and remotes areas. Once deposited, this toxin becomes available for methylation and, subsequently, the contamination of ecosystems. Implementation of air pollution regulations, however, enabled a large-scale decline in atmospheric mercury levels during the 1980s. The results shown here suggest that potential increases in emissions in the coming decades could have a similar large-scale impact on atmospheric Hg levels.
Kinetic control of TolC recruitment by multidrug efflux complexes
Authors: Tikhonova Elena B. , Dastidar Vishakha , Rybenkov Valentin V. , Zgurskaya Helen I.
Published: September 2009

In Gram-negative pathogens, multidrug efflux pumps that provide clinically significant levels of antibiotic resistance function as three-component complexes. They are composed of the inner membrane transporters belonging to one of three superfamilies of proteins, RND, ABC, or MF; periplasmic proteins belonging to the membrane fusion protein (MFP) family; and outer membrane channels exemplified by the
Escherichia coli
TolC. The three-component complexes span the entire two-membrane envelope of Gram-negative bacteria and expel toxic molecules from the cytoplasmic membrane to the medium. The architecture of these complexes is expected to vary significantly because of the structural diversity of the inner membrane transporters. How the three-component pumps are assembled, their architecture, and their dynamics remain unclear. In this study, we reconstituted interactions and compared binding kinetics of the
E. coli
TolC with AcrA, MacA, and EmrA, the periplasmic MFPs that function in multidrug efflux with transporters from the RND, ABC, and MF superfamilies, respectively. By using surface plasmon resonance, we demonstrate that TolC interactions with MFPs are highly dynamic and sensitive to pH. The affinity of TolC to MFPs decreases in the order MacA > EmrA > AcrA. We further show that MFPs are prone to oligomerization, but differ dramatically from each other in oligomerization kinetics and stability of oligomers. The propensity of MFPs to oligomerize correlates with the stability of MFP–TolC complexes and structural features of inner membrane transporters. We propose that recruitment of TolC by various MFPs is determined not only by kinetics of MFP–TolC interactions but also by oligomerization kinetics of MFPs and pH.
aPKCλ/ι promotes growth of prostate cancer cells in an autocrine manner through transcriptional activation of interleukin-6
Authors: Ishiguro Hitoshi , Akimoto Kazunori , Nagashima Yoji , Kojima Yasuyuki , Sasaki Takeshi , Ishiguro-Imagawa Yukari , Nakaigawa Noboru , Ohno Shigeo , Kubota Yoshinobu , Uemura Hiroji
Published: September 2009

Understanding the mechanism by which hormone refractory prostate cancer (HRPC) develops remains a major issue. Alterations in HRPC include androgen receptor (AR) changes. In addition, the AR is activated by cytokines such as interleukin-6 (IL-6). Atypical protein kinase C (aPKCλ/ι) has been implicated in the progression of several cancers. Herein, we provide evidence that aPKCλ/ι expression correlates with prostate cancer recurrence. Experiments in vitro and in vivo revealed aPKCλ/ι to be involved in prostate cancer cell growth through secretion of IL-6. Further, aPKCλ/ι activates transcription of the IL-6 gene through NFκB and AP-1. We conclude that aPKCλ/ι promotes the growth of hormone independent prostate cancer cells by stimulating IL-6 production in an autocrine manner. Our findings not only explain the link between aPKCλ/ι and IL-6, implicated in the progression a variety of cancers, but also establish a molecular change involved in the development of HRPC. Further, aPKCλ/ι expression might be a biomarker for prostate cancer progression.
Reelin signaling antagonizes β-amyloid at the synapse
Authors: Durakoglugil Murat S. , Chen Ying , White Charles L. , Kavalali Ege T. , Herz Joachim
Published: September 2009

Abnormal processing of the amyloid precursor protein (APP) and β-amyloid (Aβ) plaque accumulation are defining features of Alzheimer disease (AD), a genetically complex neurodegenerative disease that is characterized by progressive synapse loss and neuronal cell death. Aβ induces synaptic dysfunction in part by altering the endocytosis and trafficking of AMPA and NMDA receptors. Reelin is a neuromodulator that increases glutamatergic neurotransmission by signaling through the postsynaptic ApoE receptors Apoer2 and Vldlr and thereby potently enhances synaptic plasticity. Here we show that Reelin can prevent the suppression of long-term potentiation and NMDA receptors, which is induced by levels of Aβ comparable to those present in an AD-afflicted brain. This reversal is dependent upon the activation of Src family tyrosine kinases. At high concentrations of Aβ peptides, Reelin can no longer overcome the Aβ induced functional suppression and this coincides with a complete blockade of the Reelin-dependent phosphorylation of NR2 subunits. We propose a model in which Aβ, Reelin, and ApoE receptors modulate neurotransmission and thus synaptic stability as opposing regulators of synaptic gain control.
CKIε/δ-dependent phosphorylation is a temperature-insensitive, period-determining process in the mammalian circadian clock
Authors: Isojima Yasushi , Nakajima Masato , Ukai Hideki , Fujishima Hiroshi , Yamada Rikuhiro G. , Masumoto Koh-hei , Kiuchi Reiko , Ishida Mayumi , Ukai-Tadenuma Maki , Minami Yoichi , Kito Ryotaku , Nakao Kazuki , Kishimoto Wataru , Yoo Seung-Hee , Shimomura Kazuhiro , Takao Toshifumi , Takano Atsuko , Kojima Toshio , Nagai Katsuya , Sakaki Yoshiyuki , Takahashi Joseph S. , Ueda Hiroki R.
Published: September 2009

A striking feature of the circadian clock is its flexible yet robust response to various environmental conditions. To analyze the biochemical processes underlying this flexible-yet-robust characteristic, we examined the effects of 1,260 pharmacologically active compounds in mouse and human clock cell lines. Compounds that markedly (>10 s.d.) lengthened the period in both cell lines, also lengthened it in central clock tissues and peripheral clock cells. Most compounds inhibited casein kinase Iε (CKIε) or CKIδ phosphorylation of the PER2 protein. Manipulation of CKIε/δ-dependent phosphorylation by these compounds lengthened the period of the mammalian clock from circadian (24 h) to circabidian (48 h), revealing its high sensitivity to chemical perturbation. The degradation rate of PER2, which is regulated by CKIε/δ-dependent phosphorylation, was temperature-insensitive in living clock cells, yet sensitive to chemical perturbations. This temperature-insensitivity was preserved in the CKIε/δ-dependent phosphorylation of a synthetic peptide in vitro. Thus, CKIε/δ-dependent phosphorylation is likely a temperature-insensitive period-determining process in the mammalian circadian clock.
Physical activity and sedentary behaviours in youth: Data from three Central‐Eastern European countries
Authors: Biddle Stuart J. H. , Soos Istvan , Hamar Pal , Sandor Iosif , Simonek Jaromir , Karsai Istvan
Published: September 2009

Limited data are available on the active and sedentary behaviours of young people in Eastern Europe. Hungary, Romania, and Slovakia are relatively new members of the European Union. The socioeconomic status of the people of these countries differs from that of their Western European counterparts. These three countries are understudied in respect of physical activity and sedentary behaviour patterns in youth. Ecological momentary assessment was employed for data collection among 13‐ to 18‐year‐old students (n=623). A 3 (socioeconomic status)×3 (country)×2 (gender) multivariate analysis of variance, with physical activity, technological sedentary behaviour, and sedentary socializing behaviour as dependent variables, showed that for weekday behaviours there were significant multivariate main effects for country (P<0.001) and gender (P<0.001), but not for socioeconomic status (P>0.05). Slovakia showed greater technological sedentary behaviours than the other two countries. Romania and Slovakia had higher physical activity levels than Hungary. Boys spent more time than girls on technological sedentary behaviours, while girls spent more time than boys on socializing sedentary behaviours on weekdays and weekends (P<0.001). For weekend behaviours, the country×gender interaction was significant (P<0.046), with the highest rates of technological sedentary behaviours for males in Slovakia and Hungary, with lower figures for girls in these countries and particularly for boys and girls in Romania. There was a significant multivariate main effect for country (P<0.001), with fewer technological sedentary behaviours in Romania than the other two countries. Hungarian youth were less active than Romanian youth. These three Eastern European countries show quite high levels of sedentary behaviours but these co‐exist with varying physical activity patterns. Values differ by country and gender.
Evaluation of pre‐game hydration status, heat stress, and fluid balance during professional soccer competition in the heat
Authors: Aragón‐Vargas Luis Fernando , Moncada‐Jiménez José , Hernández‐Elizondo Jessenia , Barrenechea Alvaro , Monge‐Alvarado María
Published: September 2009

In this study, we assessed initial hydration status (stadium arrival urine specific gravity), fluid balance (pre‐ and post‐game nude body weight, fluid intake, urine collection), and core temperature changes (pre‐game, half‐time, post‐game) during a professional soccer game. We monitored 17 male players (including goalkeepers) between arrival at the stadium and the end of the game (3 h), playing at 34.9°C and 35.4% relative humidity, for an average wet bulb globe temperature (WBGT) heat stress index of 31.9°C. Data are reported as mean±standard deviation (range). Initial urine specific gravity was 1.018±0.008 (1.003–1.036); seven players showed urine specific gravity ≥ 1.020. Over the 3 h, body mass loss was 2.58±0.88 kg (1.08–4.17 kg), a dehydration of 3.38±1.11% body mass (1.68–5.34% body mass). Sweat loss was 4448±1216 ml (2950–6224 ml) versus a fluid intake of 1948±954 ml (655–4288 ml). Despite methodological problems with many players, core temperatures ≥ 39.0°C were registered in four players by half‐time, and in nine players by the end of the game. Many of these players incurred significant dehydration during the game, compounded by initial hypohydration; thermoregulation may have been impaired to an extent we were unable to measure accurately. We suggest some new recommendations for soccer players training and competing in the heat to help them avoid substantial dehydration.
Stress appraisals, coping, and coping effectiveness among international cross‐country runners during training and competition
Authors: Nicholls Adam R. , Levy Andrew R. , Grice Adam , Polman Remco C. J.
Published: September 2009

The aims of this study were to explore: (a) stressors (including intensity of the feelings that the appraisal of each stressor generated and control of the stressor) and coping strategies on training and competition days; (b) the relationship between stressor intensity and stressor control; (c) the relationship between stressor intensity and stressor control with coping effectiveness; and (d) the relationship between coping effectiveness and coping automaticity. Participants were 10 elite Caucasian cross‐country athletes who maintained a stressor and coping diary for 6 weeks. Results revealed that the runners experienced diverse stressors and used different coping strategies on training and competition days. Stressors were significantly more intense on competition days. Additionally, there was a significant negative correlation between stressor intensity and stressor control, and a negative correlation between stressor intensity and coping effectiveness. These results support the notion that stressors and coping are situation‐specific variables. Applied practitioners could thus devise situation‐specific coping interventions to maximize coping effectiveness.
Position statement: Testing physical condition in a population – how good are the methods?
Authors: Jørgensen Torben , Andersen Lars B. , Froberg Karsten , Maeder Urs , von Huth Smith Lisa , Aadahl Mette
Published: September 2009

A poor physical condition – expressed as physical inactivity and poor physical fitness – is associated with the development of chronic diseases and premature death. Our aim was to evaluate the methods currently available for measuring physical activity and physical fitness in the general population.

Physical activity is determined by duration, frequency, and intensity and derives from many different domains, making it difficult to assess over long periods and no feasible general criterion measure exists. Both objective and subjective methods are available. Of the objective methods, accelerometry is the most attractive technology, and is well enough developed for general use in large populations. The advantage of accelerometry is that it is not dependent on the memory of the individual, but its main disadvantage is that it grossly underestimates energy expenditure, due to the lack of registration of certain activities. This may be overcome to a certain extent by combining accelerometry with heart rate monitoring, although this still does not measure activity in different domains. Of the subjective methods, self‐report questionnaires are inexpensive and easy to administer. Many questionnaires have been developed, but we require (1) consensus on which measures to use for validation and (2) further development of internationally standardized questionnaires for use in different settings and to address different scientific questions. Many questionnaires correlate well with biological markers and development of chronic diseases, but subjective measurement will always entail a certain degree of misclassification. Furthermore, unstructured physical activity such as housework and gardening may be subject to recall bias. No method appears better to any other, and the choice of instrument will depend on the research question being asked. Future research should combine information from both objective and subjective methods.

Physical fitness comprises several components, including cardiorespiratory endurance and muscle strength and endurance. Direct measurement of oxygen consumption is the criterion measure for cardiorespiratory endurance. As regards muscle strength and endurance, only test–retest reliability is available. Hand‐held dynamometers greatly facilitate field testing for maximal isometric muscle strength assessment, while force plate measurements can be used for the lower extremities. For endurance, simple tests such as push‐ups and sit‐ups are reliable.
Attitude of Healthcare Personnel Regarding Influenza Immunization
Authors: Watanakunakorn Chatrchai , Ellis George , Gemmel David
Published: September 2009

Objectives:

To survey the attitudes of healthcare personnel regarding influenza immunization.

Design:

A questionnaire was given to all hospital employees.

Setting:

A 650-bed community teaching hospital.

Intervention:

Employees were offered an in-service regarding influenza immunization in October 1991. Influenza immunization was given free of charge by Employee Health Services from October to December 1991. One thousand fifty-six employees (30.2%) received influenza vaccines. Survey forms were distributed with paychecks to all employees during the second half of January 1992. Completed survey forms were returned during the next 2 weeks.

Results:

One thousand two hundred three of the 3,501 (34.3%) questionnaires were returned. Some of the survey forms were not completely filled out. A total of 28.1% of male employees (202/717) and 35.4% of female employees (987/2783) (p<.01) responded. Mean years employed were 11.35 ± 7.57 for respondents and 9.30 ± 7.39 for all employees (p<.001). Four hundred sixty-one respondents (38.4%) received the influenza vaccine and 734 (6 1.4%) did not. Among the respondents, employees who were older or working full time were more likely to receive the vaccine. Proportionally, more respondents who received the vaccine attended the in-service, although only 8.7% of those immunized attributed their receiving influenza vaccine to the in-service. More physician respondents were vaccinated. Tbe respondents who received influenza vaccine were more likely to have received the vaccine during the past 2 years (p<.001). The major reasons given for not receiving the vaccine were “bad side effects” and “do not like shots.” The major side effect of influenza immunization was a “sore arm.” Multivariate analysis suggested that the in-service was not associated with obtaining the vaccine.

Conclusions:

The in-service regarding influenza immunization seemed to have a negligible influence. Most employees who received the vaccine had previous influenza immunization. There were no major side effects of influenza immunization. “Bad side effects” and “do not like shots” were major reasons given for not receiving influenza vaccine.
Inactivation of Clostridium Difficile Spores by Disinfectants
Authors: Rutala William A. , Gergen Maria F. , Weber David J.
Published: September 2009

Objective:

The current study was designed to evaluate the activity of glutaraldehyde-based disinfectants against Clostridium difficile using the Association of Official Analytical Chemists' (AOAC) sporicidal test. This study was undertaken because gastrointestinal endoscopes that may be contaminated with C difficile spores are most commonly disinfected between patients using glutaraldehyde-based disinfectants.

Design:

Using the AOAC test, the following disinfectants were tested: 2% alkaline glutaraldehyde, 2% acid glutaraldehyde, a 1: 16 dilution of a 2% glutaraldehyde-7.05% phenol- 1.20% sodium phenate, and a 1:20 dilution of a 10% glutaraldehyde-0.5% phenylphenol-0.1% amylphenol.

Results:

Test results of the four disinfectants against C difficile spores at exposure times of 10, 20, and 60 minutes were as follows (number of positive penicylinders per 30 replicates): 0, 0, and 0 for 2% alkaline glutaraldehyde; 6, 3, and 0 for 2% acid glutaraldehyde; 30, 29, and 30 for a 1:16 dilution of glutaraldehyde- 7.05% phenol-1.20% sodium phenate; and 30, 30, and 30 for a 1:20 dilution of glutaraldehyde- 0.5% phenylphenol-0.1% amylphenol.

Conclusions:

C difficile spores are more susceptible to inactivation by glutaraldehyde-based disinfectants than the spore-forming organisms recommended in the AOAC sporicidal test (i.e., Bacillus subtilis and Clostridium sporogenes). Diluting glutaraldehyde-based disinfectants below 2% led to the inability to inactivate spores of C difficle using exposure times commonly employed to disinfect semicritical items such as gastrointestinal endoscopes.
Nosocomial Invasive Aspergillosis in Lymphoma Patients Treated with Bone Marrow or Peripheral Stem Cell Transplants
Authors: Iwen Peter C. , Reed Elizabeth C. , Armitage James O. , Bierman Philip J. , Kessinger Anne , Vose Julie M. , Arneson Mark A. , Winfield Barbara A. , Woods Gail L.
Published: September 2009

Objectives:

To determine the prevalence of aspergillosis in lymphoma patients housed in a protective environment while undergoing a bone marrow transplant or peripheral stem cell transplant and its relation to lymphoma type, type of transplant, period of neutropenia, method of diagnosis, species of Aspergillus, and the use of empiric amphotericin B.

Design:

Clinical, autopsy, and microbiology records were reviewed retrospectively to determine the presence or absence of invasive aspergillosis. All positive specimens underwent further review to determine parameters outlined above.

Setting:

The review took place at the University of Nebraska Medical Center with lymphoma patients housed in the oncology/hematology special care unit, which consists of 30 single-patient rooms under positive pressure with high-efficiency particulate air filtration.

Patients:

4 17 lymphoma patients admitted to the oncology/hematology special care unit who underwent 427 courses of high-dose chemotherapy with or without total body irradiation followed by a stem cell rescue.

Results:

Twenty-two cases (5.2%) of nosocomial invasive aspergillosis (14 caused by Aspergillus flavus, 2 by Aspergillus terreus, 2 by Aspergillus fumigatus, and 4 by characteristic histology) were diagnosed. The prevalence of disease according to transplant was 8.7% for allogeneic bone marrow transplant (2/23 treatments), 5.6% for autologous peripheral stem cell transplant (9/161), and 4.5% for autologous bone marrow transplant (11/243). Fifteen patients were presumptively diagnosed prior to death (68.2%) most commonly by histologic examination of skin biopsies. All 22 patients received amphotericin B therapy, 17 prior to aspergillosis diagnosis, and 7 (31.8%) survived. No patient with disseminated disease survived.

Conclusions:

Even when housing lymphoma patients undergoing myeloablative therapy in a protective environment containing high-efficiency particulate air filtration, there was a risk of developing aspergillosis. These data also showed that antemortem diagnosis with aggressive amphotericin B therapy was most effective in the management of infected lymphoma patients when engraftment occurred and the disease did not become disseminated.
Physical and Chemical Composition of Hospital Waste
Authors: Li Chih-Shan , Jenq Fu-Tien
Published: September 2009

For selecting the most efficient treatment method of hospital waste, the composition analysis is generally considered to be the fundamental information. Currently, there are few studies regarding the characteristics of hospital waste. This study evaluated the physical and elemental composition of the hospital waste at the National Taiwan University Hospital (NTUH). The results should help us design an incinerator for the treatment of infectious waste, plastic syringes, pathological waste, and kitchen waste. During the study period, the estimated daily waste generation rate at NTUH was 4,600 kg/day, which consisted of 4,100 kg/day noninfectious refuse, 340 kg/day infectious waste, 70 kg/day kitchen waste, 50 kg/day pathological waste, and 40 kg/day plastic syringes. The NTUH waste consisted of 99.02% combustible wastes and 0.97% noncombustible wastes by mass. The combustibie wastes constituted paper (16.17%), textiles (9.77%), cardboard, wood, and leaves (1.12%), food waste (21.5 1%), and plastics (50.45%). The noncombustible waste included 0.40% metal and 0.57% glass. Furthermore, the analysis indicated that the wastes contained 38% moisture, 4% ashes, and 58% solid with an average heat value of 3,400 kcal/kg. From the elemental analysis, the dominant elements were found to be carbon (34%) and oxygen (15%).
Validation of Surgical Wound Classification in the Operating Room
Authors: Cardo Denise M. , Falk Pamela S. , Mayhall C. Glen
Published: September 2009

Objective:

To determine the accuracy with which circulating nurses (CNs) classify surgical procedures by risk of contamination in the operating room.

Design:

Classification of surgical procedures by CNs was compared with the classification of surgical procedures by a physician observer.

Setting:

University-affiliated, tertiary care hospital.

Methods:

Circulating nurses used the traditional wound classification system of clean, clean-contaminated, contaminated, and dirty-infected to classify surgical wounds in the operating room. A physician remained in the operating room throughout each of 100 surgical procedures and simultaneously classified surgical wounds without the knowledge of the CNs.

Results:

Classification of surgical wounds by CNs was compared with classification by the physician observer for 50 cases in general surgery and 50 cases in trauma surgery. Compared with the physician observer, the overall accuracy of classification by CNs was 88% (95% confidence interval [CI] of 81.6% to 94.4%; Kappa statistic, 0.83). Classification of surgical wounds was more difficult in trauma surgery (accuracy of 82%) than in general surgery (accuracy of 94%). Accuracy increased for both services when surgical wounds were classified into just two categories (clean or clean-contaminated versus contaminated or dirty-infected).

Conclusions:

Surgical wounds can be classified in the operating room with a high degree of accuracy by CNs. Classification was more difficult in trauma than in general surgery, but classification in trauma surgery improved with feedback to and additional education of CNs. The accuracy of classification by CNs was even higher when classifications were divided into just two categories.
Oxacillin- and Quinolone-Resistant Staphylococcus Aureus in Sao Paulo, Brazil: A Multicenter Molecular Epidemiology Study
Authors: Sader Helio S. , Pignatari Antonio C. , Hollis Richard J. , Leme Ivani , Jones Ronald N.
Published: September 2009

Objective:

To investigate the possibility of interhospital spread of multiresistant Staphylococcus aureus in Sao Paulo, Brazil.

Design:

We evaluated 13 nosocomial S aureus strains selected because of resistance to oxacillin and ciprofloxacin.

Setting:

The strains were collected between March 1991 and September 1991 from four hospitals in Sao Paulo. Two were teaching hospitals, and two were private hospitals.

Patients:

Each strain was isolated from a different patient. All patients were hospitalized when the strains were isolated.

Interventions:

The strains were typed by restriction endonuclease analyses of plasmid DNA (REAP) using EcoRI, HindIII, RsaI, and Alu1 and by extended antibiogram profile (34 drugs).

Results:

All strains had identical plasmid and antibiogram profile. They demonstrated the same plasmid pattern as previously described in one of the hospitals studied.

Conclusions:

Our results suggest the dissemination of a unique oxacillin- and quinolone-resistant strain of S aureus in several hospitals of Sao Paulo, Brazil.
A Cluster of Surgical Wound Infections due to Unrelated Strains of Group A Streptococci
Authors: Jamieson F.B. , Green K. , Low D.E. , Simor A.E. , Goldman C. , Ng J. , McGeer A.
Published: September 2009

Group A streptococci account for less than 1% of all surgical wound infections but are an important cause of nosocomial outbreaks. We report here a cluster of four group A streptococcal infections that occurred within an 11-day period on a single surgical service. The index case presented with toxic shock-like syndrome. Epidemiologic investigation did not identify any relationship between infections. Restriction endonuclease analysis and M and T typing found the four isolates to be unrelated. Restriction endonuclease analysis is a useful tool for determining relatedness of nosocomial isolates of group A streptococci.
Brucellosis Among Hospital Employees in Saudi Arabia
Authors: Kiel Frank W. , Khan M. Yousuf
Published: September 2009

Objective:

To report experience with brucellosis among expatriate hospital employees in an area of the world where brucellosis is endemic.

Design:

Review of cases from the viewpoints of direct supervisor and treating physician, including epidemiologic interviews and clinical follow-up.

Setting:

Tertiary care hospital center in a developing country that increased from 125 beds to 450 beds during the period studied.

Patients:

Employees with clinical findings suggesting brucellosis and in whom a positive blood culture or significantly elevated serologic test confirmed the diagnosis.

Results:

Nine hospital employees from nonendemic areas developed brucellosis. Five were from England and four from North America. Seven were bacteriology technologists, one was a nurse, and one was an obstetrician. Each had an acute febrile illness with malaise, arthralgia, or headache. Brucella titers were ≥ 1:1,280. Five were bacteremic with positive Brucella cultures. All responded to anti-Brucella therapy. Three patients had relapses, but there were no complications.

Conclusions:

Among Saudi patients, brucellosis is generally attributable to drinking infected milk or contacting infected animals. On the other hand, among expatriate hospital employees, the infection is likely due to processing Brucella cultures or dealing with infected body fluids. In 1988, the laboratory began stricter infection control measures. Since then, there has been only one case of brucellosis among the hospital employees.
Rhodococcus
Authors: Walsh Robert D. , Schochd Paul E. , Cunha Burke A.
Published: September 2009

Infections due to Rhodococcus species are being reported with increasing frequency, especially among immunocompromised and HIV patients. R equi is the most commonly isolated species, usually from HIV patients with chronic cavitary pneumonia. Other species of Rhodococcus involved in human infections include R bronchialis, R terrae, R rhodochrous, and R aurantiacus.

Organisms belonging to the genus Rhodococcus are widely distributed in nature, but are particularly abundant in soil. Trauma, steroids, immunosuppressive therapy, surgical procedures, HIV and immune-compromised status predispose patients to infection with Rhodococcus.
Use of Biological Indicators Designed for Stream or Ethylene Oxide to Monitor a Liquid Chemical Sterilization Process
Authors: Kralovic Raymond C.
Published: September 2009

Objective:

To determine the ability of a commercially available biological indicator (BI), used to monitor steam and ethylene oxide sterilization, to biologically monitor a liquid sterilization process consisting of a sterile processor, a proprietary peracetic acid sterilant, and a sterile rinse system.

Design:

Analysis of spore survival in BIs tested in STERIS SYSTEM 1™ liquid chemical sterilization processor and in vitro.

Setting:

STERIS Corp. research laboratory.

Methods:

In vitro tests were performed in the STERIS SYSTEM 1 Processor using 12-minute and 6-minute sterilant exposure cycles. D values (time to inactivate one log of spores), spore washoff and outgrowth time, and inhibitory effects of the sterilant were determined.

Results:

Sterilization of the spore-inoculated filter paper strips in the BIs was ascertained in both processor testing and in vitro tests using conditions identical to those in the processor. The extensive washing and dilution during the processor cycle resulted in only 0.2% and 1.8% removal of the spores from Bacillus stearother-mophilus and Bacillus subtilis inoculated spore strips, respectively.

Carryover of the diluted sterilant to the culture medium did not inhibit the outgrowth of the spores, and D values could be obtained. B Stearothermophilus was two to three times more resistant to the sterilant than B subtilis. However, either spore meets the performance specifications applicable to BIs for monitoring sterilization processes.

Conclusions:

The data demonstrate that the commercial Bis evaluated are reproducible and verifiable indicators of the liquid chemical sterilization process. The same kind of performance specifications for producing BIs used to monitor steam or ethylene oxide systems also apply to the evaluated liquid chemical sterilization system.
Nosocomial Infections in Neutropenic Cancer Patients
Authors: Carlisle Penelope S. , Gucalp Rasim , Wiernik Peter H.
Published: September 2009

Objective:

Identification of overall and site-specific rates of nosocomial infection in neutropenic patients with cancer and associated pathogens.

Design:

Cumulative continuous prospective surveillance over a 42-month period. Criteria and definitions of infection in neutropenic patients (absolute neutrophil counts < 1,000/mm3) were developed, and surveillance was carried out by a certified infection control nurse and a senior oncology research fellow.

Setting:

A cancer research center with two designated oncology nursing units.

Patients:

Neutropenic patients with hematological and solid malignancies undergoing high-dose chemotherapy with and without autologous bone marrow transplantation. All patients admitted to both of the units during the study period were surveyed. Those who developed neutropenia are included in this report.

Results:

A total of 444 nosocomial infections were identified in 920 neutropenic patients during 9,582 days of neutropenia for an overall rate of 48.3 per 100 neutropenic patients, or 46.3 per 1,000 days at risk. The rate of bloodstream infection per 100 neutropenic patients was 13.5 (gram-positive, 9.2; gram-negative, 4.8; and Candida 1.2). Other site-specific rates were: urinary tract, 5.7; respiratory tract, 5.5; thrush, 6.6; skin, 3.4; and gastrointestinal tract, 3.4. Among 392 pathogens identified, there were 137 (35%) gram-positive cocci, 105 (27%) gram-negative rods, 70 (18%) Candida, 37 (9%) gram-positive rods, 22 (6%) viruses, and 15 (4%) Aspergillus.

Conclusions:

The rate of both overall and site-specific nosocomial infections in neutropenic patients is high. Neutropenia is a significant intrinsic risk factor that should be addressed in surveillance programs. Infection control and infectious diseases practitioners may need to modify techniques for surveillance, control, and management of infection in this population.