bluuebunny/crossref_metadata_2025 huggingface dataset:
The crystal structure of a bacterial, bifunctional 5, 10 methylene‐tetrahydrofolate dehydrogenase/cyclohydrolase
Authors: Shen Betty W. , Dyer David H. , Huang Jie‐Yu , D'Ari Linda , Rabinowitz Jesse , Stoddard Barry L.
Published: February 2009

The structure of a bifunctional 5, 10‐methylene‐tetrahydrofolate dehydrogenase/cyclohydrolase from Escherichia coli has been determined at 2.5 Å resolution in the absence of bound substrates and compared to the NADP‐bound structure of the homologous enzyme domains from a trifunctional human synthetase enzyme. Superposition of these structures allows the identification of a highly conserved cluster of basic residues that are appropriately positioned to serve as a binding site for the poly‐γ‐glutamyl tail of the tetrahydrofolate substrate. Modeling studies and molecular dynamic simulations of bound methylene‐tetrahydrofolate and NADP shows that this binding site would allow interaction of the nicotinamide and pterin rings in the dehydrogenase active site. Comparison of these enzymes also indicates differences between their active sites that might allow the development of inhibitors specific to the bacterial target.
Folding propensities of synthetic peptide fragments covering the entire sequence of phage 434 Cro protein
Authors: Padmanabhan S. , Jiménez M. Angeles , Rico Manuel
Published: February 2009

The phage 434 Cro protein, the N‐terminal domain of its repressor (R1–69) and that of phage λ (λ6–85) constitute a group of small, monomeric, single‐domain folding units consisting of five helices with striking structural similarity. The intrinsic helix stabilities in λ6–85 have been correlated to its rapid folding behavior, and a residual hydrophobic cluster found in R1–69 in 7 M urea has been proposed as a folding initiation site. To understand the early events in the folding of 434 Cro, and for comparison with R1–69 and λ6–85, we examined the conformational behavior of five peptides covering the entire 434 Cro sequence in water, 40% (by volume) TFE/water, and 7 M urea solutions using CD and NMR. Each peptide corresponds to a helix and adjacent residues as identified in the native 434 Cro NMR and crystal structures. All are soluble and monomeric in the solution conditions examined except for the peptide corresponding to the 434 Cro helix 4, which has low water solubility. Helix formation is observed for the 434 Cro helix 1 and helix 2 peptides in water, for all the peptides in 40% TFE and for none in 7 M urea. NMR data indicate that the helix limits in the peptides are similar to those in the native protein helices. The number of side‐chain NOEs in water and TFE correlates with the helix content, and essentially none are observed in 7 M urea for any peptide, except that for helix 5, where a hydrophobic cluster may be present. The low intrinsic folding propensities of the five helices could account for the observed stability and folding behavior of 434 Cro and is, at least qualitatively, in accord with the results of the recently described diffusion‐collision model incorporating intrinsic helix propensities.
Functional analyses of AmpC β‐lactamase through differential stability
Authors: Beadle Beth M. , Mcgovern Susan L. , Patera Alexandra , Shoichet Brian K.
Published: February 2009

Despite decades of intense study, the complementarity of β‐lactams for β‐lactamases and penicillin binding proteins is poorly understood. For most of these enzymes, β‐lactam binding involves rapid formation of a covalent intermediate. This makes measuring the equilibrium between bound and free β‐lactam difficult, effectively precluding measurement of the interaction energy between the ligand and the enzyme. Here, we explore the energetic complementarity of β‐lactams for the β‐lactamase AmpC through reversible denaturation of adducts of the enzyme with β‐lactams. AmpC from Escherichia coli was reversibly denatured by temperature in a two‐state manner with a temperature of melting (Tm) of 54.6 °C and a van't Hoff enthalpy of unfolding (ΔHVH) of 182 kcal/mol. Solvent denaturation gave a Gibbs free energy of unfolding in the absence of denaturant (ΔGu ) of 14.0 kcal/mol. Ligand binding perturbed the stability of the enzyme. The penicillin cloxacillin stabilized AmpC by 3.2 kcal/mol (ΔTm = + 5.8 °C); the monobactam aztreonam stabilized the enzyme by 2.7 kcal/mol (ΔTm = +4.9 °C). Both acylating inhibitors complement the active site. Surprisingly, the oxacephem moxalactam and the carbapenem imipenem both destabilized AmpC, by 1.8 kcal/mol (ΔTm = –3.2 °C) and 0.7 kcal/mol (ΔTm = –1.2 °C), respectively. These β‐lactams, which share nonhydrogen substituents in the 6(7)α position of the β‐lactam ring, make unfavorable noncovalent interactions with the enzyme. Complexes of AmpC with transition state analog inhibitors were also reversibly denatured; both benzo(b)thiophene‐2‐boronic acid (BZBTH2B) and p‐nitrophenyl phenylphosphonate (PNPP) stabilized AmpC. Finally, a catalytically inactive mutant of AmpC, Y150F, was reversibly denatured. It was 0.7 kcal/mol (ΔTm = –1.3 °C) less stable than wild‐type (WT) by thermal denaturation. Both the cloxacillin and the moxalactam adducts with Y150F were significantly destabilized relative to their WT counterparts, suggesting that this residue plays a role in recognizing the acylated intermediate of the β‐lactamase reaction. Reversible denaturation allows for energetic analyses of the complementarity of AmpC for β‐lactams, through ligand binding, and for itself, through residue substitution. Reversible denaturation may be a useful way to study ligand complementarity to other β‐lactam binding proteins as well.
Synthesis and NMR solution structure of an α‐helical hairpin stapled with two disulfide bridges
Authors: Barthe Philippe , Roumestand Christian , Rochette Sandrine , Vita Claudio
Published: February 2009

Helical coiled‐coils and bundles are some of the most common structural motifs found in proteins. Design and synthesis of α‐helical motifs may provide interesting scaffolds that can be useful as host structures to display functional sites, thus allowing the engineering of novel functional miniproteins. We have synthesized a 38‐amino acid peptide, α2p8, encompassing the α‐helical hairpin present in the structure of p8MTCP1, as an α‐helical scaffold particularly promising for its stability and permissiveness of sequence mutations. The three‐dimensional structure of this peptide has been solved using homonuclear two‐dimensional NMR techniques at 600 MHz. After sequence specific assignment, a total of 285 distance and 29 dihedral restraints were collected. The solution structure of α2p8 is presented as a set of 30 DIANA structures, further refined by restrained molecular dynamics, using simulated annealing protocol with the AMBER force field. The RMSD values for the backbone and all heavy atoms are 0.65 ± 0.25 and 1.51 ± 0.21 Å, respectively. Excised from its protein context, the α‐hairpin keeps its native structure: an α‐helical coiled‐coil, similar to that found in superhelical structures, with two helices spanning residues 4‐16 and 25–36, and linked by a short loop. This motif is stabilized by two interhelical disulfide bridges and several hydrophobic interactions at the helix interface, leaving most of its solvent‐exposed surface available for mutation. This α‐helical hairpin, easily amenable to synthetic chemistry and biological expression system, may represent a stable and versatile scaffold to display new functional sites and peptide libraries.
Structural studies of a baboon (Papio sp.) plasma protein inhibitor of cholesteryl ester transferase
Authors: Buchko Garry W. , Cushley Robert J. , Rozek Annett , Kennedy Michael A. , Kanda Patrick
Published: February 2009

A 38‐residue protein associated with cholesteryl ester transfer inhibition has been identified in baboons (Papio sp.). The cholesteryl ester transfer inhibitor protein (CETIP) corresponds to the N‐terminus of baboon apoC‐I. Relative to CETIP, baboon apoC‐I is a weak inhibitor of baboon cholesteryl ester transferase (CET). To study the structural features responsible for CET inhibition, CETIP was synthesized by solid‐phase methods. Using sodium dodecyl sulfate (SDS) to model the lipoprotein environment, the solution structure of CETIP was probed by optical and 1HNMR spectroscopy. Circular dichroism data show that the protein lacks a well‐defined structure in water but, upon the addition of SDS, becomes helical (56%). A small blue shift of 8 nm was observed in the intrinsic tryptophan fluorescence of CETIP in the presence of saturating amounts of SDS, suggesting that tryptophan‐23 is not buried deeply in the lipid environment. The helical nature of CETIP in the presence of SDS was confirmed by upfield 1Hα secondary shifts and an average solution structure determined by distance geometry/simulated annealing calculations using 476 NOE‐based distance restraints. The backbone (N — Cα — Cα = O ) root‐mean‐square deviation of an ensemble of 17 out of 25 calculated structures superimposed on the average structure was 1.06 ± 0.30 Å using residues V4‐P35 and 0.51 ± 0.17 Å using residues A7‐S32. Although the side‐chain orientations fit the basic description of a class A amphipathic helix, both intramolecular salt bridge formation and “snorkeling” of basic side chains toward the polar face play minor, if any, roles in stabilizing the lipid‐bound amphipathic structure. Conformational features of the calculated structures for CETIP are discussed relative to models of CETIP inhibition of cholesteryl ester transferase.
Blood kinetics of four intraperitoneally administered therapeutic candidate bacteriophages in healthy and neutropenic mice
Authors: Uchiyama Jumpei , Maeda Yoshihiro , Takemura Iyo , Chess‐Williams Russ , Wakiguchi Hiroshi , Matsuzaki Shigenobu
Published: February 2009

Due to multiple‐drug resistant bacteria, phage therapy is being revisited. Although most animal experiments focus on therapeutic efficacy, the blood clearance kinetics of phages have not been well described. For further development of an efficient therapeutic strategy, information on phage blood kinetics is important. In this study, time‐course concentration changes in peripheral blood of healthy and neutropenic mice were measured using four therapeutic phages (φMR11, KPP10, φEF24C, and KEP10). The results showed a two‐ to three‐day rapid phage clearance, which fits a two‐compartment model.
Cytosolic acetyl‐CoA synthetase affected tumor cell survival under hypoxia: the possible function in tumor acetyl‐CoA/acetate metabolism
Authors: Yoshii Yukie , Furukawa Takako , Yoshii Hiroshi , Mori Tetsuya , Kiyono Yasushi , Waki Atsuo , Kobayashi Masato , Tsujikawa Tetsuya , Kudo Takashi , Okazawa Hidehiko , Yonekura Yoshiharu , Fujibayashi Yasuhisa
Published: February 2009

Understanding tumor‐specific metabolism under hypoxia is important to find novel targets for antitumor drug design. Here we found that tumor cells expressed higher levels of cytosolic acetyl‐CoA synthetase (ACSS2) under hypoxia than normoxia. Knockdown of ACSS2 by RNA interference (RNAi) in tumor cells enhanced tumor cell death under long‐term hypoxia in vitro. Our data also demonstrated that the ACSS2 suppression slowed tumor growth in vivo. These findings showed that ACSS2 plays a significant role in tumor cell survival under hypoxia and that ACSS2 would be a potential target for tumor treatment. Furthermore, we found that tumor cells excreted acetate and the quantity increased under hypoxia: the pattern of acetate excretion followed the expression pattern of ACSS2. Additionally, the ACSS2 knockdown led to a corresponding reduction in the acetate excretion in tumor cells. These results mean that ACSS2 can conduct the reverse reaction from acetyl‐CoA to acetate in tumor cells, which indicates that ACSS2 is a bi‐directional enzyme in tumor cells and that ACSS2 might play a buffering role in tumor acetyl‐CoA/acetate metabolism. (Cancer Sci 2009; 100: 821–827)
Use of serum biomarkers in a diagnostic test for irritable bowel syndrome
Authors: LEMBO A. J. , NERI B. , TOLLEY J. , BARKEN D. , CARROLL S. , PAN H.
Published: February 2009

Background  Currently, no single serum biomarker can reliably differentiate irritable bowel syndrome (IBS) from other functional gastrointestinal disorders or organic diseases of the gastrointestinal tract.

Aim  To develop and validate a diagnostic test using serum biomarkers to detect IBS.

Methods  Ten serum biomarkers were selected from a potential panel of 140 for their ability to differentiate IBS from non‐IBS disease in blood samples from patients with IBS, other gastrointestinal disorders and healthy volunteers. A predictive modelling tool was developed to assess patterns and relationships among the 10 serum biomarkers that best differentiated IBS patients from healthy controls and patients with non‐IBS gastrointestinal disease. This model was tested in a different cohort of patients and healthy controls (n = 516) to determine the predictive accuracy of differentiating IBS from non‐IBS.

Results  The sensitivity and specificity of the 10‐biomarker algorithm for differentiating IBS from non‐IBS was 50% and 88% respectively. The positive predictive value was 81%, and the negative predictive value was 64% at 50% IBS prevalence in the validation cohort. Overall accuracy was 70%.

Conclusions  Assessing serum biomarker patterns can differentiate IBS from non‐IBS with reasonable sensitivity and specificity. Assessing serum biomarkers in an overall diagnostic strategy may allow earlier diagnosis and treatment for patients with IBS.
Review article: strategies to determine whether hypergastrinaemia is due to Zollinger–Ellison syndrome rather than a more common benign cause
Authors: MURUGESAN S. V. M. , VARRO A. , PRITCHARD D. M.
Published: February 2009

Background  As there is considerable overlap between the fasting serum gastrin concentrations found in Zollinger–Ellison syndrome and various common conditions such as Helicobacter pylori infection and acid suppressing medication use, establishing the cause of hypergastrinaemia in individual cases can sometimes be difficult.

Aim  To review the causes of hypergastrinaemia and the role of additional non‐invasive investigations in hypergastrinaemic patients.

Methods  Review of articles following a Pubmed search.

Results  As gastrinomas may cause serious complications and be potentially life threatening, investigation of hypergastrinaemic patients should particularly focus on confirming or refuting the diagnosis of Zollinger–Ellison syndrome. Establishing the cause of hypergastrinaemia may be difficult when there is only a mild‐to‐moderate elevation of fasting serum gastrin concentration and concurrent treatment with proton pump inhibitor drugs and the presence of H. pylori infection can both confuse the clinical picture. A variety of provocative tests are therefore useful for establishing whether a hypergastrinaemic patient has a gastrinoma and current evidence suggests that the secretin test should be used first line.

Conclusions  We suggest an algorithm for the investigation of patients found to have an elevated fasting serum gastrin concentration and address the roles of gastrin stimulation tests in current clinical practice.
Chemokine CC‐ligand 5 production and eosinophil activation into the upper airways of aspirin‐sensitive patients
Authors: Fuentes‐Beltrán A. , Montes‐Vizuet R. , Valencia‐Maqueda E. , Negrete‐García M. C. , García‐Cruz M. de L. , Teran L. M.
Published: February 2009

Background
Airway eosinophilia is a hallmark of aspirin‐sensitive asthma/rhinitis.

Objective
We have investigated chemokine CC‐ligand 5 (CCL5) production and its association with eosinophil activation in the upper airways of aspirin‐sensitive patients both in vivo and in vitro.

Methods
Twenty aspirin‐sensitive asthma/rhinosinusitis patients, 18 atopic‐tolerant asthma/rhinosinusitis patients and 15 healthy control subjects took part in the study. All subjects were challenged with saline and lysine‐acetylsalicylic acid (L‐asa) on separate occasions. Nasal lavages were obtained at baseline and 120 min after challenge and analysed for mediators' release.

Results
When compared with control subjects, the baseline levels of CCL5 were significantly increased in both sensitive and tolerant patients (there was no significant difference in CCL5 concentrations between these two groups, P>0.05). However, L‐asa nasal challenge induced significantly increased levels of CCL5 in the sensitive patients but not in the tolerant subjects (median: 380 vs. 140 pg/mL, P<0.0001). Similarly, the concentrations of both eosinophil cationic protein (ECP) and cysteinil leukotriene (cys‐LTs) were increased significantly in the aspirin‐sensitive but not in the tolerant patients. There was a trend towards a significant correlation between CCL5 and ECP concentrations in the sensitive patients following L‐ASA challenge. On incubation with aspirin, nasal tissue derived from aspirin‐sensitive but not that derived from tolerant subjects released increased CCL5 levels in culture. As determined by immunohistochemistry, CCL5 was predominantly localized to the nasal airway epithelium.

Conclusion
Altogether, these findings suggest that CCL5 is released in aspirin‐sensitive asthma/rhinosinusitis.
Quality‐of‐life assessment in Chinese families with food‐allergic children
Authors: Leung T. F. , Yung E. , Wong Y. S. , Li C. Y. , Wong G. W. K.
Published: February 2009

Background
Caucasian families with food‐allergic children have a compromised quality of life (QoL) for fear of life‐threatening food reactions. Such data are limited in Asian children. Based on our recent questionnaire‐based survey, 8.1% of young children recruited from local nurseries and kindergartens had parent‐reported adverse food reactions (AFRs).

Objective
This study tested the robustness of the Chinese Food Allergy Quality of Life‐Parental Burden questionnaire (FAQL‐PB) and assessed QoL in families with childhood AFR. The correlations among FAQL‐PB items were evaluated by factor analysis.

Methods
Two hundred and ninety‐eight of 3677 children aged 2–7 years had parent‐reported AFR, and 197 (66.1%) of them completed the 17 items of our self‐administered FAQL‐PB. Six hundred and thirty‐nine (18.9%) children without AFR returned this questionnaire. Factor analysis was used to delineate the inter‐relationship among the FAQL‐PB items.

Results
Cronbach α for our Chinese FAQL‐PB was 0.976, and the median (interquartile range) FAQL‐PB scores of children with and without parent‐reported AFR were 0.10 (0.02–0.32) and 0 (0–0.18), respectively (P<0.001). Factor analysis confirmed excellent correlations between FAQL‐PB items. The 17 items were clustered into two factors, which explained 79.7% of the total variance. Among children with AFR, FAQL‐PB scores increased with increasing numbers of foods that caused AFRs (P<0.001 for trend). Thirty (15.2%) children had impaired QoL, defined as average item FAQL‐PB score 0.5. Impaired QoL was associated with AFR that was caused by >3 foods (P=0.001), current food avoidance (P=0.005) and AFR caused by peanut (P=0.003), egg (P=0.011) and cow's milk (P=0.028), and current flexural dermatitis (P=0.011).

Conclusions
FAQL‐PB is a robust measure of AFR‐specific parental QoL, which is impaired in Chinese children with parent‐reported AFR. Flexural dermatitis, current food voidance and AFR caused by multiple foods are independent risk factors for lower parental QoL.
Disturbed cognitive functions after nasal provocation in patients with seasonal allergic rhinitis
Authors: Hartgerink‐Lutgens I. , Vermeeren A. , Vuurman E. , Kremer B.
Published: February 2009

Background
Allergic rhinitis (AR) reduces quality of life as a result of impaired psychological well‐being and perceived impaired cognitive functioning. Few studies have measured cognitive functions objectively and it remains uncertain whether AR leads to an objective reduction in cognitive functions.

Objective
The present study investigated whether AR is associated with a decrement in several aspects of cognitive functioning. Furthermore, the study investigated whether AR patients invest more ‘mental effort’ in order to achieve the same cognitive performances as healthy controls.

Methods
Twenty five patients with seasonal allergic rhinitis (SAR) and 26 healthy controls, matched for age, education and sex, were tested on a battery of time‐demanding and strenuous objective cognitive tests and subjective questionnaires, both before and after nasal provocation (NP). The cognitive functions assessed were sustained attention, short‐ and long‐term memory and speed of information processing. Mental effort was assessed using visual rating scales.

Results
Sustained but not short cognitive performance was impaired in patients after NP. Patients showed an increased effort on short cognitive tests.

Conclusion
SAR patients suffer from cognitive performance decrements that can be compensated by additional mental effort for short tasks only.
Serum bactericidal activity against Helicobacter pylori in patients with hypogammaglobulinaemia
Authors: Desar I M E , Van Deuren M , Sprong T , Jansen J B M J , Namavar F , Vandenbroucke-Grauls C M , van Der Meer J W M
Published: February 2009

The two major primary antibody deficiency disorders are X-linked hypogammaglobulinaemia (XLA) and common variable immunodeficiency (CVID). CVID patients have an elevated risk for gastric cancer and extra-nodal marginal zone lymphoma. Both diseases are associated with Helicobacter pylori infection. We investigated whether antibody deficiency leads to defective serum bactericidal activity against H. pylori. We also investigated the correlation with immunoglobulin (Ig)M levels and observed the terminal complement complex (TCC) activity. Sera of 13 CVID patients (four H. pylori positive), one patient with hyper-IgM syndrome, one patient with Good syndrome (both H. pylori positive), five XLA patients, four H. pylori seropositive controls, four H. pylori seronegative controls and a sample of pooled human serum (PHS) were incubated in vitro with bacterial suspensions of H. pylori for 30 min. After 72 h of culture, colony-forming units were counted. TCC formation was measured by enzyme-linked immunosorbent assay. We found that normal human serum is bactericidal for H. pylori, whereas heat-inactivated serum shows hardly any killing of H. pylori. Serum (1%) of hypogammaglobulinaemia patients has a decreased bactericidal activity against H. pylori. Helicobacter pylori-positive (HP+) normal individuals show more than 90% killing of H. pylori, whereas CVID patients show 35% killing (P = 0·007) and XLA patients only 19% (P = 0·003). Serum (1%) of HP+ volunteers showed significantly better killing compared with serum of H. pylori-negative (HP–) volunteers (P = 0·034). No correlation between (substituted) IgG levels and serum bactericidal activity was found, but a weak correlation between total serum IgM and serum bactericidal activity was found. In conclusion, serum bactericidal activity against H. pylori is decreased in patients with hypogammaglobulinaemia. Heat treatment of the serum abolished the bactericidal capacity, indicating that complement activity is essential for the bactericidal effect.
Combination use of immune complexes and a Ca2+ channel blocker azelnidipine enhances interleukin-12 p40 secretion without T helper type 17 cytokine secretion in human monocyte-derived dendritic cells
Authors: Abe T , Fuse I , Narita M , Takahashi M , Aizawa Y
Published: February 2009

Immune complexes (ICs) improve the capacity of priming specific CD8+ cytotoxic T cell responses of dendritic cells (DCs). ICs induce phosphorylation of mitogen-activated protein kinases (MAPK) and calcium influx, although the precise regulating mechanism still remains unclear. In the present study, we investigated the effect of a Ca2+ channel blocker on the phosphorylation of p38 MAPK and extracellular signal-regulated kinase (ERK) in immature monocyte-derived DCs stimulated with lipopolysaccharide (LPS) or LPS-ICs, and the production of interleukin (IL)-12 family members (p40, p70, IL-23), T helper type 17 (Th17) cytokines (IL-6 and IL-23), tumour necrosis factor (TNF)-α and IL-10 were also investigated. In comparison with LPS stimulation, LPS-ICs stimulation enhanced p38 MAPK phosphorylation significantly, which was associated with an increase in IL-12 p40 monomer/homodimer secretion. LPS-ICs also enhanced TNF-α and IL-6 secretion, but suppressed IL-23 secretion. The use of azelnidipine (Aze), a long-acting L-type Ca2+ channel blocker with a high lipid solubility, suppressed p38 MAPK phosphorylation stimulated with LPS or LPS-ICs, but surprisingly enhanced IL-12 p40 monomer/homodimer secretion stimulated with LPS-ICs. This IL-12 p40 secretion-enhancing effect was not accompanied by IL-10 or IL-23 production, but was associated with ERK phosphorylation. The use of Aze did not affect IL-12 p70 production. These results suggest that the use of Aze enhances ICs-mediated IL-12 p40 secretion without additional IL-23 secretion. Therefore, the use of Aze and ICs could be a new therapeutic approach to immunomolecular therapy, as it does not cause Th17 differentiation which induces autoimmunity or reduces anti-tumour immunity.
Cancer immunotherapy: co-stimulatory agonists and co-inhibitory antagonists
Authors: Peggs K S , Quezada S A , Allison J P
Published: February 2009

The generation and maintenance of immune responses are controlled by both co-stimulatory and co-inhibitory signalling through T cell co-receptors, many of which belong to the immunoglobulin-like superfamily or the tumour necrosis factor receptor superfamily. Agonistic or antagonistic monoclonal antibodies targeting these co-receptors have the potential to enhance immunity. Furthermore, their activity on the immunosuppressive regulatory T cell populations which are prevalent within many tumours provides an additional rationale for their use as anti-cancer therapies. This review summarizes the interactions between cancer and the immune system, highlighting the ways in which these new classes of immunostimulatory antibodies might enhance anti-tumour immunity and summarizing early clinical experience with their use.
Human gingival fibroblasts express functional chemokine receptor CXCR6
Authors: Hosokawa Y , Hosokawa I , Ozaki K , Nakae H , Matsuo T
Published: February 2009

We have reported that CXCL16, a recently discovered transmembrane chemokine, is expressed in human gingival fibroblasts (HGF). However, it is not known whether HGF express CXCR6, the receptor for CXCL16, or CXCL16 affects HGF biology. We have shown that HGF expressed CXCR6 by reverse transcription–polymerase chain reaction and flow cytometric analysis. Moreover, we elucidated that tumour necrosis factor (TNF)-α and cytosine-guanine dinucleotide (CpG) DNA (Toll-like receptor-9 ligand) treatment enhanced CXCR6 expression by HGF. Interleukin (IL)-4, IL-13 and CpG DNA up-regulated CXCR6 expression by TNF-α-stimulated HGF. On the other hand, IL-1β and interferon-γ inhibited CXCR6 expression on TNF-α-treated HGF. CXCL16 treatment induced HGF proliferation and phosphorylation of extracellular regulated kinase (ERK) and protein kinase B (AKT) in HGF. In conclusion, HGF expressed CXCR6 functionally, because CXCL16 induced HGF proliferation and ERK and AKT phosphorylation in HGF. These results indicate that CXCL16 may play an important role in the pathogenesis and remodelling in periodontally diseased tissues.
Lower bone mineral density is associated with higher coronary calcification and coronary plaque burdens by multidetector row coronary computed tomography in pre‐ and postmenopausal women
Authors: Choi Sung Hee , An Jee Hyun , Lim Soo , Koo Bo Kyung , Park Se Eun , Chang Hyuck Jae , Choi Sang Il , Park Young Joo , Park Kyong Soo , Jang Hak Chul , Shin Chan Soo
Published: February 2009

Objectives  There is growing evidence for the association between bone mineral density (BMD) and vascular calcification, which is related to cardiovascular disease. Coronary multidetector row computed tomography (MDCT) is a noninvasive tool developed to evaluate coronary status precisely. We used MDCT to evaluate this association.

Design and patients  Eight hundred and fifteen subjects received routine checkups. After excluding subjects with factors affecting bone metabolism and cardiovascular disease, 467 subjects were analysed.

Measurements  Coronary calcification was measured with MDCT and BMD was measured with dual X‐ray absorptiometry (DXA).

Results  The BMD of the femur and the lumbar spine (L‐spine) were negatively associated with the coronary calcium score (CCS) after adjusting for age in women but not in men. This inverse correlation was stronger in women with a longer time since menopause (r = −0·35 at femur, postmenopausal women vs. r = −0·10 at femur, premenopausal women, P < 0·05), and it was stronger at the femur than in the L‐spine (r = −0·35 at femur vs. r = −0·16 at L‐spine, P < 0·01). The relationship was also stronger in postmenopausal women with osteoporosis and osteopaenia than in women with normal BMD. The lower BMD was associated with higher coronary plaque burdens and multidiseased coronary vessels in both men and women (P < 0·01).

Conclusions  Increased CCS and subclinical atherosclerosis of plaque burdens as revealed by MDCT was associated with a low BMD in all women, independent of cardiovascular risk factors and age.
How do you approach the problem of TSH elevation in a patient on high‐dose thyroid hormone replacement?
Authors: Morris John C.
Published: February 2009

Persistent elevation of TSH levels in patients under treatment for hypothyroidism is a relatively common clinical problem in endocrinology practice. The most common cause for this phenomenon is poor patient compliance with their thyroid hormone tablets. In the compliant patient, however, multiple aetiologies are possible and a methodological and stepwise approach to the patient's problem will uniformly identify a cause, or at least a resolution.
Age and sex as predictors of biochemical activity in acromegaly: analysis of 1485 patients from the German Acromegaly Register
Authors: Petersenn S. , Buchfelder M. , Gerbert B. , Franz H. , Quabbe H. J. , Schulte H. M. , Grussendorf M. , Reincke M. ,   for the Participants of the German Acromegaly Register
Published: February 2009

Objective We evaluated the German Acromegaly Register for clinical variables associated with the initial biochemical activity of patients with acromegaly.

Design Retrospective analysis of data in the registry.

Patients A total of 1485 patients with acromegaly (males 45·6%, females 54·4%) were treated in 42 German endocrine centres until November 2005. Linear regression models were used to estimate the influence of various parameters on biochemical activity.

Results Male patients with acromegaly were significantly younger at the time of diagnosis than female patients (41vs.47 years,P < 0·0001) and had significantly higher random GH levels than females (21vs.14 ng/ml,P < 0·005) and IGF‐1 levels (773vs.679 ng/ml,P < 0·0001), respectively. Age at initial presentation turned out to be the most important independent risk factor associated with random GH levels, oral glucose tolerance test‐suppressed GH levels, IGF‐1 levels, body mass index (BMI), tumour size and prevalence of hypopituitarism. Sex was an independent risk factor for IGF‐1 levels, BMI and prevalence of hypopituitarism. Tumour size was an independent risk factor for both GH and IGF‐1 levels.

Conclusions In summary, initial biochemical activity of acromegaly is influenced by patient’s age and to a lesser degree by patient’s sex. Male patients are on an average 6 years younger than females.
Vitamin D and mortality in older men and women
Authors: Pilz Stefan , Dobnig Harald , Nijpels Giel , Heine Robert J. , Stehouwer Coen D. A. , Snijder Marieke B. , Van Dam Rob M. , Dekker Jacqueline M.
Published: February 2009

Objective  Vitamin D deficiency is common among the elderly and may contribute to cardiovascular disease. The aim of our study was to elucidate whether low serum levels of 25‐hydroxyvitamin D [25(OH)D] are associated with an increased risk of all‐cause and cardiovascular mortality.

Design and patients  The Hoorn Study is a prospective population‐based study among older men and women.

Measurements  Fasting serum 25(OH)D was determined in 614 study participants at the follow‐up visit in 2000–2001, the baseline for the present analysis. To account for sex differences and seasonal variations of 25(OH)D levels we formed sex‐specific quartiles, which were calculated from the 25(OH)D values of each season.

Results  After a mean follow‐up period of 6·2 years, 51 study participants died including 20 deaths due to cardiovascular causes. Unadjusted Cox proportional hazard ratios (HRs; with 95% confidence intervals) for all‐cause and cardiovascular mortality in the first when compared with the upper three 25(OH)D quartiles were 2·24 (1·28–3·92; P = 0·005) and 4·78 (1·95–11·69; P = 0·001), respectively. After adjustment for age, sex, diabetes mellitus, smoking status, arterial hypertension, high‐density lipoprotein‐cholesterol, glomerular filtration rate and waist‐to‐hip ratio, the HRs remained significant for all‐cause [1·97 (1·08–3·58; P = 0·027)] and for cardiovascular mortality [5·38 (2·02–14·34; P = 0·001)].

Conclusions  Low 25(OH)D levels are associated with all‐cause mortality and even more pronounced with cardiovascular mortality, but it remains unclear whether vitamin D deficiency is a cause or a consequence of a poor health status. Therefore, intervention studies are warranted to evaluate whether vitamin D supplementation reduces mortality and cardiovascular diseases.
Insulin‐like factor 3 as a marker of testicular function in obese men
Authors: Foresta Carlo , Di Mambro Antonella , Pagano Claudio , Garolla Andrea , Vettor Roberto , Ferlin Alberto
Published: February 2009

Objectives  Testicular function declines with obesity as a result of central and peripheral mechanisms, including a primary dysfunction of the Leydig cells. The levels of insulin‐like factor 3 (INSL3), a sensitive marker of Leydig cell impairment, have never been evaluated in obese men. To better evaluate the hormonal function of the testis in obese men, we analysed their INSL3 plasma levels and compared them with the obesity status and the other reproductive hormones.

Design  Cross‐sectional study.

Patients  Thirty‐one obese men [body mass index (BMI) >30 kg/m2) aged 22–49 years and 64 age‐matched nonobese men.

Measurements  Plasma concentrations of INSL3, testosterone (T), sex hormone‐binding globulin (SHBG), oestradiol (E2), LH, FSH. Free testosterone (FT) levels were calculated.

Results  Obese men had significantly lower plasma concentrations of total T, SHBG, FT and INSL3, and higher levels of E2 with respect to nonobese men. LH and FSH values were not different from controls. In obese men, we found a significant negative correlation between BMI and INSL3, and a positive correlation between INSL3 and T. Only one (1/31, 3·2%) obese man had subnormal T levels. On the contrary, 10/31 (32·3%) obese men had low INSL3 values.

Conclusions  This study showed for the first time that INSL3 levels decrease with obesity, probably as a result of a primary dysfunction of the Leydig cells. INSL3 is a reliable marker of Leydig cell general impairment, whereas T mainly reflects the steroidogenic activity of these cells.
Likelihood of persistent GH deficiency into late adolescence: relationship to the presence of an ectopic or normally sited posterior pituitary gland
Authors: Murray P.G. , Hague C. , Fafoula O. , Gleeson H. , Patel L. , Banerjee I. , Raabe A.L. , Hall C.M. , Wright N.B. , Amin R. , Clayton P.E.
Published: February 2009

Objectives  The presence of an ectopic posterior pituitary gland (EPP) in childhood is associated with isolated GH deficiency (IGHD) and multiple pituitary hormone deficiency. GHD in late adolescence has been defined as a peak GH level <5 μg/l. The aim of this study was to identify the likelihood of persistent GHD in late adolescence in patients with an EPP compared with those with a normally sited posterior pituitary (NPP).

Methods  In 18 patients with an EPP and 15 patients with an NPP, clinical, biochemical and radiographic data were collected.

Results  In the EPP vs. the NPP group, the change in peak GH levels at the end of growth was less (+0·4[95% confidence interval (CI) ‐ 0·8 to 2·7] vs. +4·1[95%CI + 0·4 to +10·5] μg/l, P‐value for ancova = 0·03, after adjustment for age and sex). Using a peak GH level of <5 μg/l as a cut‐off for GHD, 66% of EPP subjects compared with 40% of NPP subjects had GHD (P = 0·3). Hundred per cent of EPP subjects had a peak GH level on retesting <10 μg/l, compared with 40% of NPP subjects (P < 0·001).

Conclusion  It is important to document GH status at the end of growth, even if there is a structural abnormality of the hypothalamic–pituitary axis. The presence of an EPP compared to an NPP increases the likelihood of persistent GHD by 26%. As all EPP patients had a peak GH level of <10 μg/l, the cut‐off for persistent GHD in late adolescence may need to be revised.
Prevalence of mental disorders in acromegaly: a cross‐sectional study in 81 acromegalic patients
Authors: Sievers Caroline , Dimopoulou Christina , Pfister Hildegard , Lieb Roselind , Steffin Birgit , Roemmler Josefine , Schopohl Jochen , Mueller Marion , Schneider Harald Jörn , Ising Marcus , Wittchen Hans Ulrich , Stalla Guenter Karl
Published: February 2009

Objective  Emotional and behavioural alterations have been described in acromegalic patients. However, the nature and psychopathological value of these changes remained unclear.

We examined whether acromegalic patients have an increased prevalence of comorbid DSM‐IV (Diagnostic and Statistical Manual of Mental Disorders, 4th Version) mental disorders in comparison to subjects with or without chronic somatic disorders.

Design/patients  A cross‐sectional study was conducted at the Max‐Planck Institute of Psychiatry and the Ludwig‐Maximilians‐University Munich. Eighty‐one acromegalic patients were enrolled. Control subjects with (n = 3281) and without chronic somatic (n = 430) disorders were drawn from a representative sample of the German adult general population as part of the Mental Health Supplement of the German Health Interview and Examination Survey. Lifetime and 12‐month prevalences of DSM‐IV mental disorders were assessed with face‐to‐face interviews using the standardized German computer‐assisted version of the Composite International Diagnostic Interview.

Results  Acromegalic patients had increased lifetime rates of affective disorders of 34·6% compared to 21·4% in the group with chronic somatic disorders (OR = 2·0, 95% CI 1·2–3·2) and to 11·1% in the group without chronic somatic disorders (OR = 4·4, 95% CI 2·3–8·7). Affective disorders that occurred significantly more often than in the control groups began during the putative period of already present GH excess. Higher rates of DSM‐IV mental disorders were reported in those patients with additional treatment after surgery.

Conclusion  Acromegaly is associated with an increased prevalence and a specific pattern of affective disorders. Greater emphasis on diagnosing and treatment of mental disorders in acromegalic patients might improve the disease management.
Site prioritisation for the protection of rare subterranean species – the cases of two ostracods from south‐western France
Authors: DANIELOPOL DAN L. , ARTHEAU MALVINA , MARMONIER PIERRE
Published: February 2009

1. Delineation of protected areas for rare subterranean species is a key problem for groundwater biodiversity conservation, because of practical difficulties in implementation. Criteria for site selection are presented that are derived from studies on two remarkable Ostracoda, Dolekiella europaea Gidó, Artheau, Colin, Danielopol & Marmonier (Limnocytheridae) and Vestalenula carveli Artheau (Darwinulidae) discovered in south‐western France.

2. Arguments for natural heritage value and protection of subterranean species are proposed and illustrated by using information on these two ostracod species. The proposed criteria are: (i) local and/or regional endemism; (ii) known occurrence of the species at a few localities only; (iii) representativeness for ancient phylogenetic lineages with wider geographical distributions in the past; and (iv) suitability for scientific study because of unique morphological or biological traits.

3. It is also proposed to prioritise the protection of subsurface sites using the following criteria: (i) type locality for newly described species; (ii) presence of other rare stygobiotic taxa; and (iii) high population densities of the primary target species.

4. Development and implementation of protection strategies at local scale are likely to benefit from collaboration between scientists, policy makers and stakeholders. The measures taken should complement existing national and/or international attempts at large‐scale protection of groundwater biodiversity.
Substantial differences in littoral fish community structure and dynamics in subtropical and temperate shallow lakes
Authors: TEIXEIRA‐de MELLO FRANCO , MEERHOFF MARIANA , PEKCAN‐HEKIM ZEYNEP , JEPPESEN ERIK
Published: February 2009

1. Fish play a key role in the functioning of temperate shallow lakes by affecting nutrient exchange among habitats as well as lake trophic structure and dynamics. These processes are, in turn, strongly influenced by the abundance of submerged macrophytes, because piscivorous fish are often abundant at high macrophyte density. Whether this applies to warmer climates as well is virtually unknown.

2. To compare fish community structure and dynamics in plant beds between subtropical and temperate shallow lakes we conducted experiments with artificial submerged and free‐floating plant beds in a set of 10 shallow lakes in Uruguay (30°–35°S) and Denmark (55°–57°N), paired along a gradient of limnological characteristics.

3. The differences between regions were more pronounced than differences attributable to trophic state. The subtropical littoral fish communities were characterised by higher species richness, higher densities, higher biomass, higher trophic diversity (with predominance of omnivores and lack of true piscivores) and smaller body size than in the comparable temperate lakes. On average, fish densities were 93 ind. m−2 (±10 SE) in the subtropical and 10 ind. m−2 (±2 SE) in the temperate lakes. We found a twofold higher total fish biomass per unit of total phosphorus in the subtropical than in the temperate lakes, and as fish size is smaller in the former, the implication is that more energy reaches the littoral zone fish community of the warmer lakes.

4. Plant architecture affected the spatial distribution of fish within each climate zone. Thus, in the temperate zone fish exhibited higher densities among the artificial free‐floating plants while subtropical fish were denser in the artificial submerged plant beds. These patterns appeared in most lakes, regardless of water turbidity or trophic state.

5. The subtropical littoral fish communities resembled the fish communities typically occurring in temperate eutrophic and hypertrophic lakes. Our results add to the growing evidence that climate warming may lead to more complex and omnivory‐dominated food webs and higher density and dominance of smaller‐sized fish. This type of community structure may lead to a weakening of the trophic cascading effects commonly observed in temperate shallow lakes and a higher risk of eutrophication.
Patient acuity: a concept analysis
Authors: Brennan Caitlin W. , Daly Barbara J.
Published: February 2009

Title. Patient acuity: a concept analysis.

Aim. This paper is a report of a concept analysis of patient acuity.

Background. Patient acuity is a widely‐used term in the health sciences literature, but often without specification of its exact meaning. Concept clarification is therefore needed to delineate the meaning of patient acuity.

Data sources. A review of the Pubmed, CINAHL, MEDLINE and PsychInfo databases for the keyword ‘acuity’ in the title or abstract of papers in English language journals, as well as searches for the term ‘acuity’ and ‘acute’ in the Merriam‐Webster and Oxford English Dictionaries were the data sources for this concept analysis. Papers were excluded if ‘acuity’ was not present in the title or abstract. Publication dates of the literature included in the review ranged from 1974 to 2008.

Findings. The attributes of acuity are severity, intensity and the pairing of acuity measurements with another concept. These attributes were organized according to Holzemer’s Outcomes Model for Health Care Research as patient‐, provider‐ or system‐related. The sub‐categories of attributes identified were physical, psychological, nursing care needs, workload, complexity, case‐mix, patient classification systems, urgency/triage scales and other uses.

Conclusion. Researchers are encouraged to specify which attribute of acuity they are studying and to develop measurement tools specific to that attribute, in order to move the science towards standardization of the concept of acuity and its measurement.
Task‐oriented training in rehabilitation after stroke: systematic review
Authors: Rensink Marijke , Schuurmans Marieke , Lindeman Eline , Hafsteinsdóttir Thóra
Published: February 2009

Title. Task‐oriented training in rehabilitation after stroke: systematic review.

Aim. This paper is a report of a review conducted to provide an overview of the evidence in the literature on task‐oriented training of stroke survivors and its relevance in daily nursing practice.

Background. Stroke is the second leading cause of death and one of the leading causes of adult disability in the Western world. The use of neurodevelopmental treatment in the daily nursing care of stroke survivors does not improve clinical outcomes. Nurses are therefore exploring other forms of rehabilitation intervention, including task‐oriented rehabilitation. Despite the growing number of studies showing evidence on task‐oriented interventions, recommendations for daily nursing practice are lacking.

Data Sources. A range of databases was searched to identify papers addressing task‐oriented training in stroke rehabilitation, including Medline, CINAHL, Embase and the Cochrane Library of systematic reviews. Papers published in English between January 1996 and September 2007 were included. There were 42 papers in the final dataset, including nine systematic reviews.

Review methods. The selected randomized controlled trials and systematic reviews were assessed for quality. Important characteristics and outcomes were extracted and summarized.

Results. Studies of task‐related training showed benefits for functional outcome compared with traditional therapies. Active use of task‐oriented training with stroke survivors will lead to improvements in functional outcomes and overall health‐related quality of life.

Conclusion. Generally, task‐oriented rehabilitation proved to be more effective. Many interventions are feasible for nurses and can be performed in a ward or at home. Nurses can and should play an important role in creating opportunities to practise meaningful functional tasks outside of regular therapy sessions.