bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving the functional expression of a Bacillus licheniformislaccase by random and site-directed mutagenesis
Authors: Koschorreck Katja , Schmid Rolf D , Urlacher Vlada B 
Published: February 2009

Abstract

Background
Laccases have huge potential for biotechnological applications due to their broad substrate spectrum and wide range of reactions they are able to catalyze. These include, for example, the formation and degradation of dimers, oligomers, polymers, and ring cleavage as well as oxidation of aromatic compounds. Potential applications of laccases include detoxification of industrial effluents, decolorization of textile dyes and the synthesis of natural products by, for instance, dimerization of phenolic acids. We have recently published a report on the cloning and characterization of a CotA Bacillus licheniformis laccase, an enzyme that catalyzes dimerization of phenolic acids. However, the broad application of this laccase is limited by its low expression level of 26 mg l-1 that was achieved in Escherichia coli. To counteract this shortcoming, random and site-directed mutagenesis have been combined in order to improve functional expression and activity of CotA.

Results
A CotA double mutant, K316N/D500G, was constructed by combining random and site-directed mutagenesis. It can be functionally expressed at an 11.4-fold higher level than the wild-type enzyme. In addition, it is able to convert ferulic acid much faster than the wild-type enzyme (21% vs. 14%) and is far more efficient in decolorizing a range of industrial dyes. The investigation of the effects of the mutations K316N and D500G showed that amino acid at position 316 had a major influence on enzyme activity and position 500 had a major influence on the expression of the laccase.

Conclusion
The constructed double mutant K316N/D500G of the Bacillus licheniformis CotA laccase is an appropriate candidate for biotechnological applications due to its high expression level and high activity in dimerization of phenolic acids and decolorization of industrial dyes.
Mild hypothermia does not attenuate platelet aggregation and may even increase ADP-stimulated platelet aggregation after clopidogrel treatment
Authors: Högberg Carl , Erlinge David , Braun Oscar Ö 
Published: February 2009

Abstract

Background
Mild hypothermia is currently standard of care for cardiac arrest patients in many hospitals and a common belief is that hypothermia attenuates platelet aggregation. We wanted to examine the effects of clopidogrel on platelet aggregation during hypothermia.

Methods
Platelet reactivity at 37°C and 33°C was evaluated by light transmission aggregometry and vasodilator-stimulated phosphoprotein (VASP) in blood from healthy volunteers before, and 24 hours after, a 600 mg loading dose of clopidogrel.

Results
Collagen, 5-HT, epinephrine, U46619 and ADP-induced platelet aggregation was unaltered or even increased by hypothermia. After clopidogrel, there was a significant increase in platelet aggregation for 5 and 20 μM ADP at 33°C compared to 37°C (46 ± 5 vs. 34 ± 5% and 58 ± 4 vs. 47 ± 4%, p < 0.001, n = 8). Hypothermia also increased ADP-induced aggregation after pretreatment with the P2Y1 antagonist MRS2500. The decreased responsiveness to clopidogrel during hypothermia could be overcome by addition of the reversible P2Y12 antagonist AZD6140. ADP-induced inhibition of VASP-phosphorylation was unaffected by hypothermia both in the presence and absence of clopidogrel. A dose-response curve for ADP-induced platelet aggregation revealed increased potency for ADP during hypothermia with no difference in efficacy.

Conclusion
Mild hypothermia did not attenuate platelet aggregation, instead it even increased ADP-stimulated platelet aggregation after clopidogrel treatment. Dual platelet inhibition with aspirin and a P2Y12 receptor antagonist is probably needed for patients with acute coronary syndromes treated with mild hypothermia, and it is possible that future ADP blockers could be of benefit.
Sang Froid in a time of trouble: is a vaccine against HIV possible?
Authors: Plotkin Stanley A 
Published: February 2009

Since the announcement of the STEP trial results in the past months, we have heard many sober pronouncements on the possibility of an HIV vaccine. On the other hand, optimistic quotations have been liberally used, from Shakespeare's Henry V's “Once more unto the breach, dear friends” to Winston Churchill's definition of success as “going from one failure to another with no loss of enthusiasm”. I will forgo optimistic quotations for the phrase “Sang Froid”, which translates literally from the French as “cold blood”; what it really means is to avoid panic when things look bad, to step back and coolly evaluate the situation. This is not to counsel easy optimism or to fly in face of the facts, but I believe that while the situation is serious, it is not desperate.I should stipulate at the outset that I am neither an immunologist nor an expert in HIV, but someone who has spent his life in vaccine development. What I will try to do is to provide a point of view from that experience.There is no doubt that the results of STEP were disappointing: not only did the vaccine fail to control viral load, but may have adversely affected susceptibility to infection. But HIV is not the only vaccine to experience difficulties; what lessons can we glean from prior vaccine development?
Access to paediatric emergency departments in Italy: a comparison between immigrant and Italian patients
Authors: Grassino Erica Clara , Guidi Carla , Monzani Alice , Di Pietro Pasquale , Bona Gianni 
Published: February 2009

Abstract

Objective
The aim of the study was to investigate whether access to paediatric emergency departments differed between foreign and Italian patients.

Methods
We performed a cross-sectional study between January-December 2007 to analyse attendance's characteristics in the paediatric emergency departments of ten Italian public hospitals. The study population included each foreign patient and the following Italian patient admitted to the same emergency department. All causes of admission of these subjects were evaluated, together with the child's age, gender, country of birth, parents' nationality, time of admission, severity code and discharge-related circumstances.

Results
We enrolled 4874 patients, 2437 foreign (M:F = 1409:1028) and 2437 Italian ones (M:F = 1368:1069). Most of foreign and Italian patients' admissions were sorted as green (72.5% and 87.8%, respectively) or white codes (25.2% and 9.8%, respectively). The most frequent causes for attendance concerned respiratory tract diseases, followed by gastroenteric ones and injuries in both groups.

Conclusion
In our survey immigrants didn't access to emergency departments more than Italian children. Both of them referred to emergency departments mainly for semi-urgent or non-urgent problems. Foreign and Italian patients suffered from the same pathologies. Infectious diseases traditionally thought to be a potential problem in immigrant populations actually seem to be quite infrequent.
Perioperative Activation of Disseminated Tumor Cells in Bone Marrow of Patients With Prostate Cancer
Authors: Weckermann Dorothea , Polzer Bernhard , Ragg Thomas , Blana Andreas , Schlimok Günter , Arnholdt Hans , Bertz Simone , Harzmann Rolf , Klein Christoph A. 
Published: February 2009

Purpose The outcome of prostate cancer is highly unpredictable. To assess the dynamics of systemic disease and to identify patients at high risk for early relapse we followed the fate of disseminated tumor cells in bone marrow for up to 10 years and genetically analyzed such cells isolated at various stages of disease. Patients and Methods Nine hundred bone marrow aspirates from 384 patients were stained using the monoclonal antibody A45-B/B3 directed against cytokeratins 8, 18, and 19. Log-rank statistics and Cox regression analysis were applied to determine the prognostic impact of positive cells detected before surgery (244 patients) and postoperatively (214 patients). Samples from primary tumors (n = 55) and single disseminated tumor cells (n = 100) were analyzed by comparative genomic hybridization. Results Detection of cytokeratin-positive cells before surgery was the strongest independent risk factor for metastasis within 48 months (P < .001; relative risk [RR], 5.5; 95% CI, 2.4 to 12.9). In contrast, cytokeratin-positive cells detected 6 months to 10 years after radical prostatectomy were consistently present in bone marrow with a prevalence of approximately 20% but had no influence on disease outcome. Characteristic genotypes of cytokeratin-positive cells were selected at manifestation of metastasis. Conclusion Cytokeratin-positive cells in the bone marrow of prostate cancer patients are only prognostically relevant when detected before surgery. Because we could not identify significant genetic differences between pre- and postoperatively isolated tumor cells before manifestation of metastasis, we postulate the existence of perioperative stimuli that activate disseminated tumor cells. Patients with cytokeratin-positive cells in bone marrow before surgery may therefore benefit from adjuvant therapies.
Effectiveness of a Letter Notification Program for Women With Early-Stage Breast Cancer Eligible for Extended Adjuvant Letrozole
Authors: McArthur Heather L. , Gelmon Karen A. , Olivotto Ivo A. , Speers Caroline H. , Ellard Susan L. , O'Reilly Susan E. , Kennecke Hagen F. 
Published: February 2009

Purpose After National Cancer Institute of Canada trial MA.17 demonstrated benefits with letrozole after 5 years of tamoxifen, oncologists needed to identify and offer therapy to patients in community follow-up who were eligible for extended adjuvant hormone therapy. In British Columbia (BC), letters about extended letrozole therapy were sent to eligible BC women, their primary care physicians (PCPs), and their oncologists. We evaluated the effectiveness of this communication strategy. Patients and Methods Eight hundred eighty-five women with stage I-III breast cancer who completed 4 to 6 years of tamoxifen in 2004 with no documented recurrence were sent letters describing extended adjuvant letrozole in February 2005. Treatment uptake and characteristics for women who did or did not receive a subsequent letrozole prescription were described. Results Among 838 eligible women, 305 (36%) received a letrozole prescription before April 2006. More women in the letrozole cohort had tumors larger than 2.0 cm (44.2% v 30.8%); node-positive disease (52.5% v 22.5%); prior radiotherapy (71.1% v 58.5%); and prior chemotherapy (51.5% v 20.8%; all P ≤ .001). Among women younger than 70 years with node-positive disease, 65% received letrozole (122 of 188). Most prescribing physicians were oncologists (57.0%) or PCPs (30.8%). A significant increase in letrozole prescriptions was observed after the letter mail-out. Conclusion In this population-based setting, extended adjuvant letrozole was more common among younger women with higher risk disease and more prior therapy but underutilized overall. The reasons for extended therapy underutilization and the role of the letter mail-out strategy in informing breast cancer survivors of new available treatments in other health systems warrant further study.
PIK3CA Mutation Is Associated With Poor Prognosis Among Patients With Curatively Resected Colon Cancer
Authors: Ogino Shuji , Nosho Katsuhiko , Kirkner Gregory J. , Shima Kaori , Irahara Natsumi , Kure Shoko , Chan Andrew T. , Engelman Jeffrey A. , Kraft Peter , Cantley Lewis C. , Giovannucci Edward L. , Fuchs Charles S. 
Published: February 2009

Purpose PIK3CA mutation and subsequent activation of the AKT pathway play an important role in colorectal carcinogenesis. However, little is known about the prognostic role of PIK3CA mutation in colon cancer. Patients and Methods Using 450 resectable colon cancers (stage I to III) in two independent prospective cohorts, we detected PIK3CA mutation in 82 tumors (18%) by pyrosequencing. Cox proportional hazards models were used to calculate hazard ratios (HRs) of colon cancer–specific and overall mortalities, adjusted for patient characteristics and tumoral molecular features, including the CpG island methylation phenotype, microsatellite instability (MSI), LINE-1 hypomethylation, and p53, CIMP, KRAS and BRAF mutation. Results Compared with patients with PIK3CA wild-type tumors, those with PIK3CA-mutated tumors experienced an increase in colon cancer–specific mortality according to univariate analysis (HR = 1.64; 95% CI, 0.95 to 2.86), which persisted after adjusting for other known or potential risk factors for cancer recurrence (including MSI; multivariate HR = 2.23; 95% CI, 1.21 to 4.11). The effect of PIK3CA mutation on cancer survival seemed to differ according to KRAS mutational status. Among patients with KRAS wild-type tumors, the presence of PIK3CA mutation was associated with a significant increase in colon cancer–specific mortality (HR = 3.80; 95% CI, 1.56 to 9.27). In contrast, PIK3CA mutation conferred no significant effect on mortality among patients with KRAS-mutated tumors (HR = 1.25; 95% CI, 0.52 to 2.96). Conclusion Among patients who undergo a curative resection of colon cancer, PIK3CA mutation is associated with shorter cancer-specific survival. The adverse effect of PIK3CA mutation may be potentially limited to patients with KRAS wild-type tumors.
Significant Associations of Mismatch Repair Gene Polymorphisms With Clinical Outcome of Pancreatic Cancer
Authors: Dong Xiaoqun , Jiao Li , Li Yanan , Evans Douglas B. , Wang Huamin , Hess Kenneth R. , Abbruzzese James L. , Li Donghui 
Published: February 2009

Purpose DNA mismatch repair (MMR) is critical in maintaining genomic stability and may modulate the cellular response to gemcitabine. We hypothesized that genetic variations in MMR may affect the clinical outcome of patients with pancreatic cancer. Patients and Methods We evaluated 15 single-nucleotide polymorphisms (SNPs) of eight MMR genes in 154 patients with potentially resectable pancreatic adenocarcinoma who were enrolled onto phase II clinical trials for preoperative gemcitabine-based chemoradiotherapy from 1999 to 2006. Associations of genotypes with tumor response to therapy (change of tumor size by radiologic evaluation at restaging), margin-negative tumor resection, and overall survival were evaluated using logistic regression and Cox proportional regression models. Results Five, six, and 10 genotypes were significantly associated with tumor response to preoperative chemoradiotherapy, tumor resectability, and overall survival, respectively, in univariable analysis. TREX1 EX14-460C>T and TP73 Ex2+4G>A genotypes remained as significant predictors for tumor response, MLH1 IVS12-169C>T and TP73 remained as significant predictors for tumor resectability, and EXO1 R354H, TREX1, and TP73 remained as significant predictors for overall survival in multivariable models that included all clinical factors and genotypes examined. A strong combined genotype effect on each clinical end point was observed. For example, 20 of the 25 patients with zero to one adverse genotypes were alive, those with two, three, four, five, and six to seven adverse genotypes had median survival times of 36.2, 23.9, 16.3, 13.0, and 8.3 months, respectively (P < .001). Conclusion SNPs of MMR genes have a potential value as predictors for clinical response to chemoradiotherapy and as prognostic markers for tumor resectability and overall survival of patients with resectable pancreatic cancer.
Oogenesis defects in a mutant mouse model of oculodentodigital dysplasia
Authors: Tong Dan , Colley Deanne , Thoo Renee , Li Tony Y. , Plante Isabelle , Laird Dale W. , Bai Donglin , Kidder Gerald M. 
Published: February 2009

SUMMARY
The essential role of connexin43 (Cx43) during oogenesis has been demonstrated by the severe germ cell deficiency and arrested folliculogenesis observed in Cx43 knockout mice. Recently, another mutant mouse strain became available (Gja1Jrt/+) that carries the dominant loss-of-function Cx43 mutation, Cx43G60S. Gja1Jrt/+ mice display features of the human disease oculodentodigital dysplasia (ODDD), which is caused by mutations in the GJA1 gene. We used this new mutant strain to study how a disease-linked Cx43 mutant affects oogenesis. We found that female mutant mice are subfertile with significantly reduced mating success and small litters. The phosphorylated species of the Cx43 protein are reduced in the mutant ovaries in association with impaired trafficking and assembly of gap junctions in the membranes of granulosa cells, confirming that the mutant protein acts dominantly on its wild-type counterpart. Correspondingly, although starting with a normal abundance of germ cells, ovaries of the mutant mice contain significantly fewer pre-ovulatory follicles and do not respond to superovulation by gonadotropins, which is at least partially the result of reduced proliferation and increased apoptosis of granulosa cells. We conclude that the Gja1Jrt mutation has a dominant negative effect on Cx43 function in the ovary, rendering the females subfertile. Given these findings, closer examination of reproductive function in ODDD human females is warranted.
Human embryonic stem cell-derived motor neurons expressing SOD1 mutants exhibit typical signs of motor neuron degeneration linked to ALS
Authors: Karumbayaram Saravanan , Kelly Theresa K. , Paucar Andres A. , Roe Anne J. T. , Umbach Joy A. , Charles Andrew , Goldman Steven A. , Kornblum Harley I. , Wiedau-Pazos Martina 
Published: February 2009

SUMMARYHuman embryonic stem cell (hESC)-derived neurons have the potential to model neurodegenerative disorders. Here, we demonstrate the expression of a mutant gene, superoxide dismutase 1(SOD1), linked to familial amyotrophic lateral sclerosis (ALS) in hESC-derived motor neurons. Green fluorescent protein (GFP) expression under the control of the HB9 enhancer was used to identify SOD1-transfected motor neurons that express human wild-type SOD1 or one of three different mutants (G93A, A4V and I113T) of SOD1. Neurons transfected with mutant SOD1 exhibited reduced cell survival and shortened axonal processes as compared with control-transfected cells, which could survive for 3 weeks or more. The results indicate that hESC-derived cell populations can be directed to express disease-relevant genes and to display characteristics of the disease-specific cell type. These genetically manipulated hESC-derived motor neurons can facilitate and advance the study of disease-specific cellular pathways, and serve as a model system to test new therapeutic approaches.
Esulatin G, a Novel Nor-diterpenoid from Euphorbia esula
Authors: Wang Yu-Bo , Wang Hong-Bing , Ji Ping , Guo Jie , Jin Hui-Zi , Qin Guo-Wei 
Published: February 2009

Abstract
From aerial parts of Euphorbia esula esulatin G (1), a novel norparaliane diterpenoid, together with its biosynthetic precursor 5,8,14-triacetoxy-3-benzoyloxy-15-hydroxy-9-oxoparaliane (2) was isolated. Their structures were determined by extensive spectroscopic analysis (IR, MS, NMR, and X-ray diffraction).
Gel-hydrothermal Preparation of Hollow CoFe2O4 Nanospheres and Their Properties
Authors: Chen Lingyun , Zhao Chenglan , Bai Junfeng 
Published: February 2009

Abstract
Hollow CoFe2O4 nanospheres were successfully prepared through hydrothermal decomposition of a gel of Co–Fe–glycol in solution. The products have average diameters of ca. 80 nm with a Brunauer–Emmett–Teller (BET) surface area of about 76.5 m2·g−1, exhibiting low saturation magnetization and high coercivity.
Rumphellolide I, a Novel Caryophyllane-related Tetrahydropyran Norsesquiterpenoid from Gorgonian Coral Rumphella antipathies
Authors: Sung Ping-Jyun , Su Yin-Di , Hwang Tsong-Long , Chuang Li-Fan , Chung Hsu-Ming , Chen Jih-Jung , Li Jan-Jung , Fang Lee-Shing , Wang Wei-Hsien 
Published: February 2009

Abstract
A novel caryophyllane-related norsesquiterpenoid, rumphellolide I (1), which possessing an unprecedented cyclic ether bridge between C-4 and C-8, was isolated from the gorgonian coral Rumphella antipathies. The structure of 1 was established by spectral data analysis and this compound showed moderate inhibitory effects on elastase release by human neutrophils.
Sensitive Detection of Hydroxyl Radical Production in Ultrasonic Field with an Electrochemiluminescence Optical Sensor
Authors: Jin Jiye , Kumeta Hiroaki , Takahashi Fumiki , Asakura Yoshiyuki 
Published: February 2009

Abstract
A new method of cavitation diagnostics with an electrochemiluminescence (ECL) optical sensor is described for study of the hydroxyl radical production by ultrasonic cavitation. Because of the high sensitivity of this method, it is possible to measure the sonochemical activity in situ, so as to obtain spatial distribution of the cavitation zone in the ultrasound field.
Governance Instruments That Protect Children's Environmental Health: Is Enough Being Done?
Authors: Spady Donald , Ries Nola , Ladd Brian D. , Buka Irena , Osornio-Vargas Alvaro Roman , Soskolne Colin L. 
Published: February 2009

We describe our efforts to find and assess governance instruments: laws, regulations, guidelines, addressing specifically the issue of children's environmental health in OECD countries in the European Union (EU) and in the United States of America (US). The ultimate purpose is to inform policy that will further Canada's commitment to children's environmental health. Among governance instruments found, most EU country governance instruments duplicated EU Directives; American governance instruments were found at both the federal and state level. With a few clear exceptions, the effects of environmental agents on the child have not been considered specifically in those OECD governance instruments that address environmental health concerns. We found multiple governance instruments with a clear children's environmental health focus, but little emphasis on the uniqueness of children. We also found laws not specifically addressing children in the text, but which clearly involved concern for child health. Some legislation was impeded because of scientific uncertainty, which, on occasion, appeared to be industry-driven. The precautionary principle appeared to be applied most frequently in European legislation. We conclude that children's environmental health is not well-addressed for the majority of laws relating to the environment.
Conformal mapping of multiply connected Riemann domains by a variational approach
Authors: Hildebrandt Stefan , von der Mosel Heiko 
Published: February 2009

Abstract
We show with a new variational approach that any Riemannian metric on a multiply connected schlicht domain in ℝ2 can be represented by globally conformal parameters. This yields a “Riemannian version” of Koebe's mapping theorem.
Test strip handling in screening for drugs of abuse in the clinical toxicological setting1
Authors: Wilhelm Lars , Jenckel Stefan , Junker Ralf 
Published: February 2009

Abstract
Test strips for detecting narcotics are being used more frequently – ranging from clinical issues to forensically relevant cases. Analyses are not always done by staff trained in toxicology. Pharmacological and toxicological knowledge is necessary for the interpretation of the results as well as the technical understanding of the test system (e.g., cut-off values, cross reactivity). False negative results have to be considered possible when interpreting results. Suitable measures should be taken to rule out sample manipulation to the widest extent possible. To ensure the accuracy and reproducibility of analytical results, quality checks will have to be carried out. Analytical results will be reproducible only when backed up by the necessary documentation. Further diagnosis involving chromatographic methods should be carried out to differentiate and confirm positive findings. National and international rules and regulations regarding decision limits should be observed.