bluuebunny/crossref_metadata_2025 huggingface dataset:
Interaction of Cochlear Nucleus Explants With Semiconductor Materials
Authors: Mlynski Robert , Volkenstein Stefan , Hansen Stefan , Brors Dominik , Ebmeyer Joerg , Dazert Stefan
Published: May 2007

Objective/Hypothesis: Implantable hearing devices such as cochlear implants and auditory brainstem implants deliver auditory information through electrical stimulation of auditory neurons. The combination of microelectronic electrodes with auditory nerve cells may lead to further improvement of the hearing quality with these devices. Whereas several kinds of neurons are known to grow on semiconductor substrates, interactions of cochlear nucleus (CN) neurons with such materials have yet to be described.

Materials and Methods: To investigate survival and growth behavior of CN neurons on different semiconductor materials. CN explants from postnatal day 10 Sprague‐Dawley rats were cultured for 96 hours in Neurobasal medium on polished and unpolished silicon wafers (p‐type Si {100} and p‐type Si3N4{100}) as well as plastic surface. These surfaces had been coated with poly‐L‐lysine and laminin. Neuronal outgrowth was examined using image analysis software after immunohistologic staining for neurofilament. Neurite length and directional changes were quantified. Additionally, neurite morphology and adhesion to the semiconductor material was evaluated by scanning electron microscopy.

Results: Although proper adhesion of CN explants was seen, no neurite growth could be detected on unpolished silicon wafers (Si and Si3N4). Compared with the other test conditions, polished, laminin‐coated Si3N4 wafers showed best biocompatibility regarding neurite length and number per explant. CN explants developed a mean of eight neurons with an average length of 236 μm in 96 hours of culture on these wafers.

Conclusion: The results of this study demonstrate the general possibility of CN neuron growth in culture on semiconductors in vitro. The differences in neuron length and number per explant indicate that the growth of CN neurons is influenced by the semiconductor substrate as well as extracellular matrix proteins, with laminin‐coated p‐type Si3N4{100} being a preferable material for future hybrid experiments on auditory‐neuron semiconductor chips.
Isolation of a novel mouse gene, mSVS‐1/SUSD2, reversing tumorigenic phenotypes of cancer cells in vitro
Authors: Sugahara Tetsuo , Yamashita Yzumi , Shinomi Masahito , Yamanoha Banri , Iseki Hiroyoshi , Takeda Akihiko , Okazaki Yasushi , Hayashizaki Yoshihide , Kawai Kenji , Suemizu Hiroshi , Andoh Toshiwo
Published: May 2007

We report isolation of a novel tumor‐reversing gene, tentatively named SVS‐1, encoding a protein of 820 amino acids with localization on the plasma membrane as a type I transmembrane protein. The gene was found among those downregulated in the activated oncogene‐v‐K‐ras‐transformed NIH3T3 cells, Ki3T3, with tumorigenic phenotype. SVS‐1 protein harbors several functional domains inherent to adhesion molecules. Histochemical staining of mouse tissues using antibody raised against the protein showed the expression of the protein in restricted regions and cells, for example, strongly positive in apical membranes of epithelial cells in renal tubules and bronchial tubes. The protein inducibly expressed in human fibrosarcoma HT1080 cells and cervical carcinoma HeLa cells was found to be localized primarily on the plasma membrane, as stained with antibodies against FLAG tag in the N‐terminus and against the C‐terminal peptide of the protein. Expression of the protein in cells induced a variety of biological effects on cancer cells: detachment from the substratum and aggregation of cells and growth inhibition in HeLa cells, but no inhibition in non‐tumorigenic mouse NIH3T3 cells. Inhibition of clonogenicity, anchorage‐independent growth, migration and invasion through Matrigel was also observed. Taken together these results suggest that the SVS‐1 gene is a possible tumor‐reversing gene. (Cancer Sci 2007; 98: 900–908)
Therapeutic potential of the dual‐targeted TAS‐102 formulation in the treatment of gastrointestinal malignancies
Authors: Temmink Olaf H. , Emura Tomohiro , De Bruin Michiel , Fukushima Masakazu , Peters Godefridus J.
Published: May 2007

Current treatment modalities for cancer combine cytotoxic drugs against DNA and novel targeted drugs affecting signal transduction pathways, which are required for growth progression and metastasizing tumors. Classical chemotherapeutic regimens for gastro‐intestinal tumors include antimetabolites based on 5‐fluorouracil (5FU), the platinum analog oxaliplatin and the topoisomerase inhibitor irinotecan. The thymidine analog trifluorothymidine (TFT) has been shown to bypass resistance pathways for 5FU derivatives (S‐1, UFT, Xeloda) in model systems, while concurrent application with a thymidine phosphorylase inhibitor (TPI) increases the bioavailability of TFT, thereby potentiating the in vivo efficacy of TFT. The formulation TAS‐102 is given orally in a 1.0:0.5 molar ratio (TFT:TPI). The formulation is dual‐targeted due to the cytotoxic effect of TFT, which is enhanced by TPI, while TPI also exerts antiangiogenic effects by inhibiting thymidine phosphorylase (TP), also known as platelet‐derived endothelial cell growth factor. Evidence is accumulating from in vitro and in vivo preclinical studies that these properties favor further combinations with other cytotoxic agents currently being used in the treatment of gastro‐intestinal tumors. Also treatment with targeted agents will synergistically down‐regulate signal transduction pathways responsible for growth and progression of tumors. In this review, we summarize the available information on (clinical) pharmacology, mechanisms of action, pharmacodynamic and pharmacokinetic properties, early clinical trials and future directions of the new potent combination drug TAS‐102. (Cancer Sci 2007; 98: 779–789)
Gastric and intestinal claudin expression at the invasive front of gastric carcinoma
Authors: Matsuda Yoshiko , Semba Shuho , Ueda Junya , Fuku Takeichi , Hasuo Tadateru , Chiba Hideki , Sawada Norimasa , Kuroda Yoshikazu , Yokozaki Hiroshi
Published: May 2007

Like gastric and intestinal mucins, the tight junction proteins called claudins can be used to determine the differentiation of gastric mucosa. We investigated the expression of claudins in gastric cancer and proposed a new claudin‐based gastric cancer classification system. The expression of gastric (claudin‐18) and intestinal (claudin‐3 and claudin‐4) claudins in non‐neoplastic gastric mucosa (with intestinal metatplasia [IM], 78 cases; without IM, 88 cases) and 94 gastric cancers was analyzed immunohistochemically, as was the expression of gastric (MUC5A and MUC6) and intestinal (CD10 and MUC2) mucins. Heterogeneous expression of claudin‐3, claudin‐4 and claudin‐18 was detected in advanced gastric cancer; however, there was no significant association between the claudins and the clinicopathological parameters. These gastric cancer tissues were also subclassified into claudin‐based phenotypes: gastric claudin (G‐CLDN), 28 cases (30%); intestinal claudin (I‐CLDN), 41 cases (44%); and unclassified claudin (U‐CLDN), 25 cases (26%). Interestingly, the U‐CLDN gastric cancers had worse malignancy grades, not only in size and invasiveness but also in potential metastatic ability and patient outcome. Although the mucin‐based gastric cancer classification was also assessed, no significant correlation was found between mucin production and clinicopathological parameters. These observations suggest that loss of claudin expression may enhance the grade of malignancy of gastric cancer in vivo. Classification of gastric cancers using gastric and intestinal claudins is a good biomarker for assessing the risk of poor prognosis. (Cancer Sci 2007; 98: 1014–1019)
BCL2L2 is a probable target for novel 14q11.2 amplification detected in a non‐small cell lung cancer cell line
Authors: Kawasaki Tsutomu , Yokoi Sana , Tsuda Hitoshi , Izumi Hiroyuki , Kozaki Ken‐ichi , Aida Shinsuke , Ozeki Yuichi , Yoshizawa Yasuyuki , Imoto Issei , Inazawa Johji
Published: May 2007

Amplification of chromosomal DNA is thought to be one of the mechanisms that activates cancer‐related genes in tumors. In a previous genome‐wide screening of DNA copy number aberrations in a panel of non‐small cell lung cancer (NSCLC) cell lines using an in‐house bacterial artificial chromosome‐based array, we identified a novel amplification at 14q11.2 in HUT29 cells derived from human lung adenocarcinoma. To identify the most likely target for the 14q11.2 amplification, we determined the extent of the amplicon by fluorescence in situ hybridization and then analyzed NSCLC cell lines for the expression levels of 28 genes present within the 1‐Mb amplified region. Significant overexpression in the HUT29 cell line with amplification, relatively frequent overexpression in additional NSCLC cell lines compared with an immortalized normal lung epithelial cell line, and reported information about the function of each candidate gene prompted us to characterize the BCL2‐like2 (BCL2L2) gene, a prosurvival member of the BCL2 family, as the most likely target for the 14q11.2 amplicon. Immunohistochemical analysis of 61 primary cases of lung adenocarcinoma demonstrated that BCL2L2 overexpression was significantly associated with tumor stage and differentiation status, and tended to be associated with a poorer prognosis. Downregulation of BCL2L2 expression using small interfering RNA dramatically inhibited the growth of HUT29 cells, but showed no effect on anticancer reagent‐induced cell death of the same cell line. These findings demonstrate that overexpressed BCL2L2, through amplification or other mechanisms, promotes the growth of NSCLC, especially the adenocarcinoma subtype, and might be a therapeutic target. (Cancer Sci 2007; 98: 1070–1077)
Robin Coombs: his life and contribution to haematology and transfusion medicine
Authors: Pamphilon Derwood H , Scott Marion L
Published: May 2007

Robin Coombs was the last survivor of the distinguished group of immunologists that included Philip Gell, John Humphrey, John Marrack, Peter Medawar and Robert White and who were responsible for the renaissance of British Immunology after the Second World War. He is best remembered for describing the antiglobulin test that bears his name. The antiglobulin test revolutionised the diagnosis of haemolytic diseases and the compatibility testing of blood for transfusion. In all, Coombs authored over 200 scientific papers. Haemagglutination reactions became widely used in the diagnosis of a range of infectious agents. Together with Philip Gell, he devised the classification of allergic reactions; these were published in the textbook ‘Clinical Aspects of Immunology’, which he and Gell first edited in 1963 and which became the leading textbook on medical immunology. Robin Coombs was also one of the founders of the British Society for Immunology.
Impact of imatinib therapy on the use of allogeneic haematopoietic progenitor cell transplantation for the treatment of chronic myeloid leukaemia
Authors: Giralt Sergio A. , Arora Mukta , Goldman John M. , Lee Stephanie J. , Maziarz Richard T. , McCarthy Philip L. , Sobocinski Kathleen A. , Horowitz Mary M. ,   on behalf of the Chronic Leukemia Working Committee of the Center for International Blood and Marrow Transplant Research
Published: May 2007

The discovery and approval of imatinib drastically changed the therapeutic algorithm for chronic myeloid leukaemia (CML). Imatinib is now considered the therapy of choice for patients with newly diagnosed CML, including those previously considered candidates for allogeneic haematopoietic cell transplantation (HCT). We compared numbers and types of allogeneic HCTs performed for CML in North America before and after the introduction of imatinib, and publication of the International Randomized Trial of Interferon and STI571 (IRIS) using transplants reported to the Center for International Blood and Marrow Transplant Research (CIBMTR). The number of HCTs for CML registered with the CIBMTR in 1998 was 617; 62% were performed in first chronic phase (CP1). Only 1% of patients had received imatinib prior to transplantation. In 2003, the number of HCTs reported was 223; 44% were performed in CP1 and 77% of patients received imatinib prior to transplantation. The introduction of imatinib therapy has had a profound impact on the use of allogeneic transplantation for CML, with a marked decrease in the number of transplants for CML and an accompanying decrease in the proportion done in CP1. Most patients now receive a trial of imatinib before proceeding to HCT.
G‐CSF is not necessary to maintain over 99% dose–intensity with ABVD in the treatment of Hodgkin lymphoma: low toxicity and excellent outcomes in a 10‐year analysis
Authors: Evens Andrew M. , Cilley Jeffrey , Ortiz Taylor , Gounder Mrinal , Hou Nanjiang , Rademaker Alfred , Miyata Sarah , Catsaros Kara , Augustyniak Connie , Bennett Charles L , Tallman Martin S. , Variakojis Daina , Winter Jane N. , Gordon Leo I.
Published: May 2007

Dose–intensity of chemotherapy is important in the treatment of Hodgkin lymphoma (HL) and granulocyte‐colony stimulating factor (G‐CSF) is commonly used to maintain it. We reviewed all newly diagnosed HL patients who were treated at our institution between 1996 and 2005. Fifty‐nine patients received adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD) chemotherapy with no dose reductions, treatment delays, and without G‐CSF, regardless of absolute neutrophil count (ANC). The median ANC on all ABVD treatment days (n = 658) was 0·925 × 109/l, and was <0·5 × 109/l on 26% of treatment days. Median normalised ABVD dose–intensity was 99·1% (range, 93–100%) and median cycle duration was 28·2 d. Incidence of bleomycin lung toxicity was 1·6%, 0·44% treatments were complicated by febrile neutropenia, and no secondary malignancies have occurred (median follow‐up 48 months; range, 11–130 months). Five‐year event‐free (EFS) and overall survival (OS) were 92·9% and 97·4% respectively. Furthermore, the 5‐year EFS and OS (87·4% and 94·1% respectively) for advanced stage patients compared favourably with a similar ABVD patient group who received routine prophylactic G‐CSF (n = 23) with EFS 80·0% and OS 91·3% (P = 0·46 and 0·67 respectively). Our experience suggests that ABVD may be safely and effectively administered at >99% dose–intensity without G‐CSF support, regardless of the ANC.
The 13q and 11q B‐cell chronic lymphocytic leukaemia‐associated regions derive from a common ancestral region in the zebrafish
Authors: Auer Rebecca L. , Riaz Sophia , Cotter Finbarr E.
Published: May 2007

Loss of the long arm of chromosomes 11 and 13 is the most consistent cytogenetic abnormalities for patients with B‐cell chronic lymphocytic leukaemia (B‐CLL). They suggest the presence of as yet unidentified tumour suppressor genes within well‐defined minimal‐deleted regions (MinDRs). We have identified 38 orthologues of the human genes in MinDRs in zebrafish cDNA and syntenic regions for the human deletions in the zebrafish genome. One region on chromosome 9 in the zebrafish genome is of potential interest. Within chromosome 9, five genes and two microRNAs were identified with shared synteny to the MinDRs in B‐CLL (two genes to human chromosome 11, three to human chromosome 13 and two chromosome 13 microRNAs). The critical region on zebrafish chromosome 9 maps to the MinDR for both human chromosomes, suggesting a common ancestry for B‐CLL tumour suppressor genes. Target‐selected mutagenesis to identify zebrafish mutants with knock‐outs of genes in this region will allow analysis of their in vivo potential for lymphoproliferation and may define causative genes for B‐CLL within human chromosomes 11q and 13q. Our study provides an explanation for involvement of both 11q and 13q in B‐CLL and the potential to develop animal models for this common lymphoproliferative disorder.
Serum leptin, oxidized low density lipoprotein and plasma asymmetric dimethylarginine levels and their relationship with dyslipidaemia in adolescent girls with polycystic ovary syndrome
Authors: Demirel Fatma , Bideci Aysun , Cinaz Peyami , Çamurdan M. Orhun , Biberoğlu Gürsel , Yesilkaya Ediz , Hasanoğlu Alev
Published: May 2007

Objective  The aim of this study was to investigate serum leptin, oxidized low density lipoprotein (ox‐LDL) and asymmetric dimethylarginine (ADMA) levels and their interaction with dyslipidaemia in adolescents with polycystic ovary syndrome (PCOS).

Patients and design  The study group consisted of 23 obese (obPCOS) and 21 nonobese girls with PCOS (nPCOS), and 31 lean healthy controls. PCOS was defined by the National Institutes of Health (NIH) criteria as the presence of chronic oligoanovulation and hyperandrogenism. Fasting leptin, ox‐LDL, ADMA and detailed lipid‐lipoprotein profile were determined. Atherogenic index (AI) was calculated as [Total cholesterol − HDL cholesterol/HDL cholesterol]. Logarithmic transformations were made for ox‐LDL.

Results  Total cholesterol, triglycerides, LDL cholesterol, very low density lipoprotein (VLDL) cholesterol, apolipoprotein B, lipoprotein A levels and AI were higher and apolipoprotein AI was lower in obPCOS compared to those in controls (P < 0·05). LDL cholesterol, apolipoprotein B and lipoprotein A levels were higher in nPCOS compared to controls (P < 0·05). ADMA and ox‐LDL levels did not differ in the three groups. Leptin was significantly higher in obPCOS compared with that in the other two groups (P < 0·001) and it was correlated with triglycerides (r = 0·62), VLDL cholesterol (r = 0·45), lipoprotein A (r = 0·38) and AI (r = 0·43) in the PCOS group (P < 0·05).

Conclusion  Our data demonstrate that ADMA and ox‐LDL levels in adolescent PCOS subjects were not different than those in controls. Abnormal lipid profile was shown in obese and nonobese girls with PCOS and leptin was related with these lipid abnormalities in the PCOS subjects.
Cardiac biomarkers and survival in haemodialysis patients
Authors: Sommerer C. , Beimler J. , Schwenger V. , Heckele N. , Katus H. A. , Giannitsis E. , Zeier M.
Published: May 2007

Background  In dialysis patients, cardiac troponin T (cTNT) is often elevated despite the absence of acute myocardial ischaemia, and amino‐terminal pro‐B‐natriuretic peptide (NT‐proBNP) is markedly higher compared to non‐haemodialysis patients. In a longitudinal observation, we evaluated the association of cTNT and NT‐proBNP on cardiovascular morbidity and mortality in haemodialysis patients with and without fluid overload.

Materials and methods  Plasma cTNT levels of 134 haemodialysis patients were measured before and after a dialysis session by 3rd generation electro‐chemoluminiscence immunoassay. NT‐proBNP was determined using a polyclonal antibody recognizing the N‐terminal fragment of BNP (Elecsys autoanalyzer 2010, Roche Diagnostics, Mannheim, Germany). Volume status was determined by a clinical score system. Cardiovascular morbidity and mortality were assessed over a follow‐up period of 36 months.

Results  Plasma cTNT > 0·03 ng mL−1 was found in 39·6% of all patients. Patients with hypervolaemia had significantly higher cTNT levels compared to euvolaemic patients (median 0·054 ng mL−1, interquartile range 0·019–0·153 vs. 0·005 ng mL−1, < 0·001–0·034; P < 0·001). All haemodialysis patients had excessively high levels of NT‐proBNP (median 4524; interquartile range 2000–10 250 pg mL−1), and NT‐proBNP was significantly higher in hypervolaemic haemodialysis patients (11 988, 5307–19 242) compared to euvolaemic haemodialysis patients (3247, 1619–5574); P < 0·001. Receiver operator curves showed a threshold of cTNT > 0·026 ng mL−1 and NT‐proBNP > 5300 pg mL−1 as predictors of hypervolaemia. Asymptomatic chronic haemodialysis patients with cTNT > 0·026 ng mL−1 and NT‐proBNP > 5300 pg mL−1 were more likely to die due to cardiac events in the follow‐up period. Multivariate analysis documented that elevated cTNT and NT‐proBNP levels were highly predictive for cardiovascular events.

Conclusions  Plasma levels of cTNT are elevated in approximately 40% and NT‐proBNP levels in 100% of asymptomatic chronic haemodialysis patients. Both parameters depend on volume status. Increased NT‐proBNP and cTNT are strongly associated with adverse outcome in end‐stage renal disease patients undergoing haemodialysis, and are a useful tool for risk stratification in chronic haemodialysis patients.
Co‐administration of ezetimibe and simvastatin in acute myocardial infarction
Authors: Chenot F. , Montant P. F. , Marcovitch O. , Blaimont M. , De Meester A. , Descamps O. S.
Published: May 2007

Background  Recent trials in acute myocardial infarction indicate that intensive and early statin therapy that lowers low‐density lipoprotein cholesterol (LDL‐C) to ≤ 70 mg dL−1 is beneficial. The combination of statins with ezetimibe, a newly developed cholesterol‐absorption inhibitor, can lead to a further reduction in LDL‐C of up to 26%. In this study, we examined the rapidity and intensity of the lipid‐lowering effect of ezetimibe co‐administered with simvastatin immediately after myocardial infarction.

Materials and methods  Sixty patients admitted for acute myocardial infarction were randomized to receive either simvastatin 40 mg (SIMVA), a combination of simvastatin 40 mg and ezetimibe 10 mg (EZE/SIMVA), or no lipid‐lowering drugs (NLLD) and had their lipid levels assessed 2, 4 and 7 days later.

Results  At baseline, cardiovascular risk factors were similar in all three groups [mean (SD) LDL‐C of 141 (36) mg dL−1]. At days 2 , 4 and 7 there was no significant change in mean LDL‐C levels in the NLLD group (−10%, −6%, and −9%, all P > 0·09), while there were significant reductions with SIMVA (−15%, −27%, and −25%, respectively, all P < 0·001 vs. day 0) and even greater reductions with co‐administration of EZE/SIMVA (−27%, −41%, and −51%, respectively, all P < 0·001 vs. day 0). The percentages of patients achieving LDL‐C below 70 mg dL−1 at days 4 and 7 were substantially greater with EZE/SIMVA (45% and 55%, respectively) than with SIMVA (5% and 10%, respectively), while no NLLD patient reached this goal. Triglyceride levels showed a progressive increase in the NLLD group (+45% at day 7, P < 0·05 vs. day 0), no change in the SIMVA group, but a decrease in the EZE/SIMVA group (−17% at day 7, P < 0·05 vs. day 0). No significant difference in HDL‐C levels, tolerability, or clinical events was observed between the three groups.

Conclusions  The co‐administration of ezetimibe 10 mg with simvastatin 40 mg, by inhibiting cholesterol absorption and production, allowed more patients with acute myocardial infarction to reach LDL‐C ≤ 70 mg dL−1 as early as the fourth day of treatment. The effects of such rapid and intense reduction in LDL‐C on cardiovascular morbidity and mortality need to be evaluated in future clinical endpoint studies.
Biological variation of asymmetric dimethylarginine and related arginine metabolites and analytical performance goals for their measurement in human plasma
Authors: Blackwell S. , O’Reilly D. St. J. , Talwar D.
Published: May 2007

Background  Asymmetric dimethylarginine (ADMA) is an endogenous competitive inhibitor of nitric oxide synthase which is believed to be a cause of endothelial dysfunction and has been shown to predict the occurrence of acute coronary events. Data regarding the biological variation of arginine and its methylated derivatives are conspicuously absent from the literature. Such data are important in setting analytical quality specifications, assessing the utility of population reference intervals and assessing the significance of changes in serial results from an individual.

Materials and methods  Arginine, homoarginine, ADMA and symmetric dimethylarginine (SDMA) are measured in plasma by high performance liquid chromatography. Twelve healthy volunteers underwent weekly blood sampling for 20 weeks in order to determine the intra‐ and inter‐individual biological variation of these analytes, from which analytical quality specifications, indices of individuality (II) and reference change values (RCV) are derived. Plasma samples from 100 healthy individuals were obtained in order to determine population reference intervals.

Results  ADMA and symmetric dimethylarginine (SDMA) exhibit low intra‐individual biological variation of 7·4% and 5·8%, respectively, imposing desirable imprecision goals (CVA) of ≤ 3·7% and 2·9% for these analytes. The described methodology achieves these goals, with analytical CVs of < 3·5% for all analytes. Goals for bias and total error were 3·1–10·1% and 7·2–16·0%, respectively. Reference intervals for ADMA and SDMA were 0·29–0·63 µmol L−1 and 0·24–0·55 µmol L−1, but have IIs < 1. RCVs were at least 20% for all analytes studied.

Conclusions  Dimethylarginine concentrations are tightly controlled in health, with the result that imprecision goals for laboratory methods require to be low. Relatively large differences are required between serial results to denote a significant change. Population reference intervals for dimethylarginines are likely to be of limited value in detecting ‘abnormality’ in an individual from a single result.
Low‐cycle fatigue of NiTi rotary instruments of various cross‐sectional shapes
Authors: Cheung G. S. P. , Darvell B. W.
Published: May 2007

Aim  To compare the low‐cycle fatigue (LCF) behaviour of some commercial NiTi instruments subjected to rotational bending, a deformation mode similar to an engine‐file rotating in a curved root canal, using a strain‐life analysis, in water.

Methodology  A total of 286 NiTi rotary instruments from four manufacturers were constrained into a curvature by three rigid, stainless steel pins whilst rotating at a rate of 250 rpm in deionized water until broken. The number of revolutions was recorded using an optical counter and an electronic break‐detection circuit. The surface strain amplitude, calculated from the curvature (from a photograph) and diameter of the fracture cross‐section (from a scanning electron micrograph), was plotted against the number of cycles to fracture for each instrument. A regression line was fitted to the LCF lives for each brand; the value was compared with that of others using one‐way analysis of variance (anova). The number of crack origins observed on the fractographic view was examined with chi‐square for differences amongst various groups.

Results  A linear strain‐life relationship, on logarithmic scales, was obtained for the LCF region with an apparent fatigue‐ductility exponent ranging from −0.40 to −0.56. The number of crack‐initiation sites, as observed on the fracture cross‐section, differed between brands (χ2, P < 0.05), but not LCF life (one‐way anova, P > 0.05).

Conclusions  The LCF life of NiTi instruments declines with an inverse power function dependence on surface strain amplitude, but is not affected by the cross‐sectional shape of the instrument.
Bond strength between fibre posts and composite resin cores: effect of post surface silanization
Authors: Wrbas K. T. , Schirrmeister J. F. , Altenburger M. J. , Agrafioti A. , Hellwig E.
Published: May 2007

Aim  To evaluate the tensile bond strength between two different composite resin cores and (ClearfilTMCore, MultiCore® Flow) and fibre posts (DT Light Post®), with and without silanization of the post surface.

Methodology  Forty fibre posts were shortened to a length of 15 mm. Specimens were then produced by covering the upper 3 mm of the posts with standardized composite core build‐ups. The bonding surfaces of twenty posts were treated with silane coupling agent (Monobond‐S). Four experimental groups were formed: G1: ClearfilTMCore; G2: Monobond‐S + ClearfilTMCore; G3: MultiCore® Flow; G4: Monobond‐S + MultiCore® Flow. Each post was positioned upright in a post centric device with moulds to ensure standardized shapes of the abutments. After tensile bond strength testing, the type of failure at the interface was determined. The results obtained were compared using an unpaired sample t‐test.

Results  The mean tensile bond strengths and standard deviations were [MPa] 10.08 ± 0.92 for ClearfilTMCore, 10.47 ± 1.05 for ClearfilTMCore + silane; 6.65 ± 0.79 for MultiCore® Flow and 6.91 ± 0.83 for MultiCore® Flow + silane. Statistical analysis revealed that ClearfilTMCore achieved significantly higher bond strengths than MultiCore® Flow (P < 0.0001). Post silanization had no significant effect. All tested specimens had an adhesive failure mode.

Conclusion  Type of composite had a significant effect on tensile bond strength. Silanization of fibre post surfaces had no effect on core retention.
A collagen ‘bio‐molecular film’ex vivo model to evaluate the efficacy of dynamic irrigation using the RinsEndo® system
Authors: McGill S. , Gulabivala K. , Ng Y.‐L.
Published: May 2007

Aim  To evaluate the efficacy of three irrigation protocols using a model consisting of a standard collagen film coating the root canal walls of extracted teeth.

Methodology  Thirty human teeth with single straight canals were randomly allocated to three groups for static (n = 10), manual dynamic (n = 20) or automated dynamic (n = 10) irrigation. The root canals were prepared to apical size 40 with a 0.08 taper. The teeth were split longitudinally to give two halves and stained collagen was applied to the canal surfaces in a standard manner. The re‐assembled teeth were irrigated using one of the protocols. Digital images were taken of the canal surfaces before and after irrigation with 18 mL of NaOCl. Static irrigation consisted of simple placement of an irrigation needle (gauge 30) in a fixed orientation 4 mm or 10 mm short of the working length. Manual dynamic irrigation consisted of push–pull agitation of the placed irrigant with a well‐fitting, tapered gutta‐percha point. Automated dynamic irrigation was carried out using the RinsEndo® system. The percentage canal surface coverage with stained collagen was calculated using a software package (ipWin4®). The data were analyzed using paired‐t tests and GEE linear regression models.

Results  The area of canal covered with stained collagen was significantly (P < 0.001) less (21% or 16%, respectively) after manual or automated dynamic irrigation compared with static irrigation. However, the RinsEndo® system was significantly (P = 0.037) less effective (5%) than manual dynamic irrigation. The ‘corono‐apical level of canal’ and the ‘depth of needle tip penetration’ emerged as significant factors influencing outcome of irrigation. Residual collagen was least evident in the middle third, followed by apical and then coronal thirds. Deeper penetration of the needle tip resulted in 7.5% (P < 0.001) more effective collagen removal. The orientation of the side‐port of the irrigation needle was not a significant factor (P = 0.051).

Conclusions  Automated dynamic irrigation using RinsEndo® system was significantly more effective (16%) in removing stained collagen from the root canal than static irrigation. However, it was significantly less effective (5%) than manual dynamic irrigation. Irrigation was more effective (7%) when the needle was placed closer to the apex.
Testosterone decreased urinary‐frequency in nNOS‐deficient mice
Authors: Muto Satoru , Yasuda Mitsuko , Kamiyama Yutaka , Ide Hisamitsu , Horie Shigeo
Published: May 2007

To observe the effect of testosterone on the frequency of urination in mice lacking neuronal nitric oxide synthase (nNOS−/−), we compared the urination patterns between unanaesthetized male wild‐type (n = 27) and nNOS−/− mice (n = 50) with or without testosterone treatment. Compared with wild‐type mice, nNOS−/− mice showed a greater frequency of urination during a 24‐h observation period (3.0 vs. 5.4 times/day, p < 0.0001) without any significant difference in the total voided volume or the functional voiding capacity. While testosterone treatment did not affect the urination patterns in wild‐type, it decreased the daytime frequency of urination (5.4 vs. 3.7 times, p = 0.0198) and the nighttime urination (4.4 vs. 2.9 times, p = 0.039) in nNOS−/− mice. The nNOS−/− mice can be a useful animal model for urinary frequency. Testosterone improved the functional abnormalities in the voiding of nNOS−/− mice.
Occupational health nurses’ perceptions of their current and future roles
Authors: Mellor Gary , St John Winsome
Published: May 2007

Title. Occupational health nurses’ perceptions of their current and future roles

Aim.  This paper is a report of an investigation of Australian occupational health nurses’ perceptions of their current and future roles.

Background.  Occupational health nurses are expected to engage in a variety of traditional curative activities as well as emergent role activities focusing on injury prevention, health promotion, wellness, management and research. However, little is known about the importance they place on traditional and emergent activities in both current and future practice.

Method.  The 416 members of the Australian College of Occupational Health Nurses were asked in 2002–03 to complete a questionnaire with items based on the College's areas of practice. The items related to perceived importance and time dedicated to traditional and contemporary role activities. One hundred completed questionnaires were returned, but only 93 were suitable for analysis (response rate 22%).

Findings.  Currently, Australian occupational health nurses engage in traditional curative and emergent wellness, management and research activities, but traditional activities dominate their work. Participants perceived that in the future activities related to wellness, management and research will be more important to their practice and that they will need to devote more time to them.

Conclusion.  Education programmes will need to address specifically the knowledge and skills required for wellness‐based models of practice in occupational health nursing, as well as research and negotiating skills for working with others in the workplace.
Does obesity prevent the needle from reaching muscle in intramuscular injections?
Authors: Zaybak Ayten , Güneş Ülkü Yapucu , Tamsel Sadık , Khorshid Leyla , Eşer İsmet
Published: May 2007

Title. Does obesity prevent the needle from reaching muscle in intramuscular injections?

Aim.  This paper is a report of a study to measure subcutaneous tissue thickness at the dorsogluteal and ventrogluteal sites and to determine optimal needle length for dorsogluteal and ventrogluteal intramuscular injections in adults with a body mass index of more than 24·9 kg/m2.

Background.  Problems can arise if drugs designed to be absorbed from muscle are only delivered into subcutaneous tissue. Increasing obesity in all developed and many developing countries makes this an increasing concern.

Method.  Ultrasound measurements were made of the subcutaneous tissue of overweight, obese and extremely obese people at the dorsogluteal and ventrogluteal sites with the probe held at a 90° angle to the plane of the injection site. Subcutaneous tissue thickness was measured in 119 adults whose body mass index was ≥25 kg/m2. The data were collected in 2005–2006.

Results.  Mean subcutaneous tissue thickness at the dorsogluteal site was 34·5 mm for overweight adults, 40·2 mm for obese adults and 51·4 mm for extremely obese adults, and at the ventrogluteal site was 38·2 mm for overweight adults, 43·1 mm for obese adults and 53·8 mm for extremely obese adults.

Conclusion.  Intramuscular injections administered at the dorsogluteal site in 98% of women and 37% of men, and at the ventrogluteal site in 97% of women and 57% of men, would not reach the muscles of the buttock. A needle longer that 1·5 inches should be used in women whose body mass index is more than 24·9 kg/m2, the dorsogluteal site may be used in all overweight and obese men, and the ventrogluteal site may be used in overweight men only.
Using the Care Dependency Scale for fall risk screening
Authors: Mertens Elke I. , Halfens Ruud J.G. , Dassen Theo
Published: May 2007

Title. Using the Care Dependency Scale for fall risk screening

Aim.  This paper is a report of a study conducted to estimate the sensitivity and specificity of the Care Dependency Scale as a measure of risk of falling for individuals in hospital and nursing home settings.

Background.  Falls and their consequences are common problems in hospitals and nursing homes and nurses should assess the potential risks of their patients. Items in fall risk scales resemble a general nursing assessment, which leads to redundant assessment procedures. It would be beneficial to have a single generic instrument for general assessment and fall risk screening.

Methods.  Standardized questionnaires were used in a cross‐sectional study in 2004 and data were gathered from 9943 German nursing home residents and hospital patients (response rate 77·1%). Sensitivity and specificity of all Care Dependency Scale scores were calculated for fall risk. Relationships between the 15 scale items and falls were described using odds ratios and logistic regression analysis.

Findings.  Patients with falls in hospitals were more care dependent than those without falls. Sensitivity and specificity values showed that with the Care Dependency Scale a differentiation is possible between the falls group and the no‐falls group. High odds ratios and logistic regression analysis suggest that the Care Dependency Scale item ‘Avoidance of danger’ indicated fall risk. Nursing home residents with and without falls had similar care dependency scores.

Conclusion.  Nursing assessment in hospitals could be simplified by using the Care Dependency Scale for fall risk screening. Its value in fall risk screening in nursing homes requires further testing.
Spheres of influence or autonomy? A discourse analysis of the introduction of Nurse Practitioners in rural and remote Australia
Authors: Turner Clare , Keyzer Dirk , Rudge Trudy
Published: May 2007

Title. Spheres of influence or autonomy? A discourse analysis of the introduction of Nurse Practitioners in rural and remote Australia

Aim.  This paper is a report of a study to examine the social discourses of nursing within health care as these produce understandings about autonomy for Nurse Practitioners, where autonomy refers to the ability of Nurse Practitioners to practise as professionals in their own right.

Background.  Nurse Practitioners were recently introduced to the nursing career pathways in Australia. Despite a plethora of international information, the role implementation in rural and remote Australia is slow with a number of influences emerging to hinder progress.

Method.  Critical discourse analysis was used to examine the differences between policy and the reality of implementation. The notion of autonomy was used to explore texts in policy documents relating to Nurse Practitioner authorization and published between 1995 and 2006, and these were compared with the experiences of nurses working in Nurse Practitioner positions.

Findings.  Policy texts indicate support for advanced practice and the autonomy of Nurse Practitioners. The process for authorization; however, has constraints which support nurses’ progress but also hinder it. Subsequent acceptance of Nurse Practitioners has also been problematic as colleagues struggle to understand the role within the current healthcare system.

Conclusions.  There is a significant gap between the rhetoric of policy and the implementation of Nurse Practitioner roles in rural and remote Australia. Whilst policy supports the notion of autonomy, the experiences of nurses indicate a mere shift in the traditionally‐accepted boundaries of nurses’ roles. Evidence from the United Kingdom and United States of America suggests that the findings in this study are relevant internationally as well as nationally.
Effects of ecogeographic variables on genetic variation in montane mammals: implications for conservation in a global warming scenario
Authors: Ditto Amy M. , Frey Jennifer K.
Published: May 2007

Aim  Evolutionary theory predicts that levels of genetic variation in island populations will be positively correlated with island area and negatively correlated with island isolation. These patterns have been empirically established for oceanic islands, but little is known about the determinants of variation on habitat islands. The goals of this study were twofold. Our first aim was to test whether published patterns of genetic variation in mammals occurring on montane habitat islands in the American Southwest conformed to expectations based on evolutionary theory. The second aim of this research was to develop simple heuristic models to predict changes in genetic variation that may occur in these populations as a result of reductions in available mountaintop habitat in response to global warming.

Location  Habitat islands of conifer forest on mountaintops in the American Southwest.

Methods  Relationships between island area and isolation with measures of allozyme variation in four species of small mammal, namely the least chipmunk (Tamias minimus), Colorado chipmunk (Tamias quadrivittatus), red squirrel (Tamiasciurus hudsonicus), and Mexican woodrat (Neotoma mexicana), were determined using correlation and regression techniques. Significant relationships between island area and genetic variation were used to develop three distinct statistical models with which to predict changes in genetic variation following reduction in insular habitat area arising from global warming.

Results  Patterns of genetic variation in each species conformed to evolutionary predictions. In general, island area was the most important determinant of heterozygosity, while island isolation was the most important determinant of polymorphism and allelic diversity. The heuristic models predicted widespread reductions in genetic variation, the extent of which depended on the population and model considered.

Main conclusions  The results support a generalized pattern of genetic variation for any species with an insular distribution, with reduced variation in smaller, more isolated populations. We predict widespread reductions in genetic variation in isolated populations of montane small mammals in the American Southwest as a result of global warming. We conclude that climate‐induced reductions in the various dimensions of genetic variation may increase the probability of population extinction in both the short and long term.
The phylogeography of palm cockatoos, Probosciger aterrimus, in the dynamic Australo‐Papuan region
Authors: Murphy Stephen A. , Double Michael C. , Legge Sarah M.
Published: May 2007

Aims  We aimed to investigate the effects of historical land–sea boundary and vegetation dynamics in the Australo‐Papuan region on the genetic structure of palm cockatoo populations. In doing so, we also sought to clarify the intraspecific taxonomic status of palm cockatoos, and to examine the potential conservation implications of our results.

Location  New Guinea and northern Australia.

Methods  We examined mtDNA (domain III, control region) genetic structure in 71 palm cockatoos from 17 locations across their Australo‐Papuan range.

Results  Twenty polymorphic sites over 242‐base pairs defined 12 haplotypes that were arranged in a 95% confidence parsimony network of six one‐step clades. Half of these were linked in one clade that included birds from eastern New Guinea–Australia, and the other half included birds from western New Guinea. Nested clade analyses revealed strong and significant genetic structure between these two clades. The average nucleotide divergence between eastern and western birds is c. 3.3%. Within the western clade there was a non‐random distribution of haplotypes according to sampling location alone, but the locations did not cluster significantly, probably due to low sample sizes. A non‐random distribution of haplotypes emerged within one of the one‐step clades from the east of the range (once rare haplotypes were removed), although the historic mechanism that may have created this pattern is unclear. The underlying low nucleotide divergence (0.39%) among haplotypes within the eastern clade suggests relatively recent common ancestry.

Main conclusions  Our results suggest genetic isolation of the eastern and western clades sometime during the Pleistocene. The continual reappearance of land bridges associated with Pleistocene glacio‐eustatic cycles within the eastern part of the range provides an explanation for our results. We suggest that the occurrence of two deep marine troughs maintained a narrow mountainous barrier between eastern and western birds throughout much of the Pleistocene at a time when extensive land bridges formed elsewhere in the species’ range, and that this has maintained their genetic distinctiveness. Our results provide little support for the current accepted subspecies; the western clade is roughly congruent with Probosciger aterrimus goliath (with caveats), but the otherwise unstructured small genetic distances cast considerable doubt on the remaining subspecies. The eastern and western lineages are endemic to each area and should therefore be considered for independent conservation status and management.
Well‐being of institutionalized elders after Yang‐style Tai Chi practice
Authors: Chen Kuei‐Min , Hsu Ya‐Chuan , Chen Wen‐Ting , Tseng Hung‐Fu
Published: May 2007

Aims and objectives.  The purpose of this study was to examine the effects of Tai Chi on the physical and psychological well‐being of elders who resided in long‐term care facilities.

Background.  The beneficial effects of Tai Chi on elders’ well‐being have been well‐documented; however, most of the studies focused on community‐dwelling or healthier elders.

Design and methods.  In this longitudinal, time‐series, quasi‐experimental study, a convenience sample of 28 institutionalized elders was recruited. A six‐month Yang‐style Tai Chi intervention was administered twice a week for 60 minutes per practice. The well‐being outcome variables, including physical and mental health status, blood pressure, quality of sleep, occurrence of falls and fear of falling, were measured before the intervention and then at one‐month, two‐month, three‐month and six‐month intervals.

Results.  Results indicated that the physical health status and social functioning of frail elders were significantly improved after Tai Chi practice [F(4,24) = 3·42, p = 0·038; F(4,24) = 9·66, p = 0·001 respectively].

Conclusions.  Tai Chi practice is beneficial for frail older people.

Relevance to clinical practice.  The findings provide a basis for using Yang‐style Tai Chi as a floor activity in long‐term care facilities to promote the well‐being of the older residents.