bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mercury-photosensitized decomposition of dimethyl ether. Part III. The combination of radicals
Authors: Loucks Leon F. 
Published: May 2006

As part of the study of the mercury-photosensitized decomposition of dimethyl ether, the combination of methyl radicals has been investigated in the temperature range 200 to 300 °C and at pressures between 3 and 300 mm Hg. For pressures of less than 100 mm the second-order rate coefficient for the combination of methyl radicals shows a pressure dependence. The pressure dependence agrees qualitatively with that observed by others, but occurs at somewhat higher pressures. Calculations for the Kassel equation using the Arrhenius parameters for ethane decomposition and fitted to the pressure dependence of the methyl radical combination show that the number of effective modes for ethane decomposition is 8 or 9. Carbon dioxide was found to be a quite ineffective third body for energy transfer. The results for the mercury-photosensitized decomposition of dimethyl ether have also been analyzed to obtain information about the combination of methyl radicals with methoxymethyl radicals. The combination of these radicals becomes pressure dependent at pressures less than about 15 mm. Kassel integrations based on the rate constant [Formula: see text]for the unimolecular decomposition of methyl ethyl ether at the C—C bond, and fitted to the observed pressure dependence of the combination reaction, lead to s = 10 for these reactions.The rate constant for the abstraction of a hydrogen atom by a methyl radical from dimethyl ether was found to be [Formula: see text]
Cationic platinum(II) complexes with acetylenes
Authors: Kong Pi-Chang , Theophanides T. 
Published: May 2006

A new series of cationic platinum(II) acetylene complexes of the general formula [PtacenX]n+Y−n (with n = 1, 2), where X = Cl, Br, I, Y = Cl−, Br−, PtCl42−, PtBr42−, [Formula: see text], and en = ethylenediamine, have been prepared. The infrared spectra of the complexes are discussed in relation to their structures and chemical properties. The effect of the anions on the infrared vibrations of the glycol and the ethylenediamine is also discussed.
Leukemogenesis induced by wild-type and STI571-resistant BCR/ABL is potently suppressed by C/EBPα
Authors: Ferrari-Amorotti Giovanna , Keeshan Karen , Zattoni Michela , Guerzoni Clara , Iotti Giorgio , Cattelani Sara , Donato Nick J. , Calabretta Bruno 
Published: May 2006

AbstractChronic phase–to–blast crisis transition in chronic myelogenous leukemia (CML) is associated with differentiation arrest and down-regulation of C/EBPα, a transcription factor essential for granulocyte differentiation. Patients with CML in blast crisis (CML-BC) became rapidly resistant to therapy with the breakpoint cluster region–Abelson murine leukemia (BCR/ABL) kinase inhibitor imatinib (STI571) because of mutations in the kinase domain that interfere with drug binding. We show here that the restoration of C/EBPα activity in STI571-sensitive or -resistant 32D-BCR/ABL cells induced granulocyte differentiation, inhibited proliferation in vitro and in mice, and suppressed leukemogenesis. Moreover, activation of C/EBPα eradicated leukemia in 4 of 10 and in 6 of 7 mice injected with STI571-sensitive or -resistant 32D-BCR/ABL cells, respectively. Differentiation induction and proliferation inhibition were required for optimal suppression of leukemogenesis, as indicated by the effects of p42 C/EBPα, which were more potent than those of K298E C/EBPα, a mutant defective in DNA binding and transcription activation that failed to induce granulocyte differentiation. Activation of C/EBPα in blast cells from 4 patients with CML-BC, including one resistant to STI571 and BMS-354825 and carrying the T315I Abl kinase domain mutation, also induced granulocyte differentiation. Thus, these data indicate that C/EBPα has potent antileukemia effects even in cells resistant to ATP-binding competitive tyrosine kinase inhibitors, and they portend the development of anti-leukemia therapies that rely on C/EBPα activation.
Construction of a nurse shark (Ginglymostoma cirratum) bacterial artificial chromosome (BAC) library and a preliminary genome survey
Authors: Luo Meizhong , Kim HyeRan , Kudrna Dave , Sisneros Nicholas B , Lee So-Jeong , Mueller Christopher , Collura Kristi , Zuccolo Andrea , Buckingham E Bryan , Grim Suzanne M , Yanagiya Kazuyo , Inoko Hidetoshi , Shiina Takashi , Flajnik Martin F , Wing Rod A , Ohta Yuko 
Published: May 2006

AbstractBackgroundSharks are members of the taxonomic class Chondrichthyes, the oldest living jawed vertebrates. Genomic studies of this group, in comparison to representative species in other vertebrate taxa, will allow us to theorize about the fundamental genetic, developmental, and functional characteristics in the common ancestor of all jawed vertebrates.AimsIn order to obtain mapping and sequencing data for comparative genomics, we constructed a bacterial artificial chromosome (BAC) library for the nurse shark,Ginglymostoma cirratum.ResultsThe BAC library consists of 313,344 clones with an average insert size of 144 kb, covering ~4.5 × 1010bp and thus providing an 11-fold coverage of the haploid genome. BAC end sequence analyses revealed, in addition to LINEs and SINEs commonly found in other animal and plant genomes, two new groups of nurse shark-specific repetitive elements, NSRE1 and NSRE2 that seem to be major components of the nurse shark genome. Screening the library with single-copy or multi-copy gene probes showed 6–28 primary positive clones per probe of which 50–90% were true positives, demonstrating that the BAC library is representative of the different regions of the nurse shark genome. Furthermore, some BAC clones contained multiple genes, making physical mapping feasible.ConclusionWe have constructed a deep-coverage, high-quality, large insert, and publicly available BAC library for a cartilaginous fish. It will be very useful to the scientific community interested in shark genomic structure, comparative genomics, and functional studies. We found two new groups of repetitive elements specific to the nurse shark genome, which may contribute to the architecture and evolution of the nurse shark genome.
Chronic renal insufficiency among Asian Indians with type 2 diabetes: I. Role of RAAS gene polymorphisms
Authors: Prasad Pushplata , Tiwari Arun K , Kumar KM Prasanna , Ammini AC , Gupta Arvind , Gupta Rajeev , Sharma AK , Rao AR , Nagendra R , Chandra T Satish , Tiwari SC , Rastogi Priyanka , Gupta B Lal , Thelma BK 
Published: May 2006

AbstractBackgroundRenal failure in diabetes is mediated by multiple pathways. Experimental and clinical evidences suggest that renin-angiotensin-aldosterone system (RAAS) has a crucial role in diabetic kidney disease. A relationship between the RAAS genotypes and chronic renal insufficiency (CRI) among type 2 diabetes subjects has therefore been speculated. We investigated the contribution of selected RAAS gene polymorphisms to CRI among type 2 diabetic Asian Indian subjects.MethodsTwelve single nucleotide polymorphisms (SNPs) from six genes namely-renin (REN), angiotensinogen (ATG), angiotensin converting enzyme I (ACE), angiotensin II type 1 receptor (AT1) and aldosterone synthase (CYP11B2) gene from the RAAS pathway and one from chymase pathway were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and tested for their association with diabetic CRI using a case-control approach. Successive cases presenting to study centres with type 2 diabetes of ≥2 years duration and moderate CRI diagnosed by serum creatinine ≥3 mg/dl after exclusion of non-diabetic causes of CRI (n = 196) were compared with diabetes subjects with no evidence of renal disease (n = 225). Logistic regression analysis was carried out to correlate various clinical parameters with genotypes, and to study pair wise interactions between SNPs of different genes.ResultsOf the 12 SNPs genotyped, Glu53Stop in AGT and A>T (-777) in AT1 genes, were monomorphic and not included for further analysis. We observed a highly significant association of Met235Thr SNP in angiotensinogen gene with CRI (O.R. 2.68, 95%CI: 2.01–3.57 for Thr allele, O.R. 2.94, 95%CI: 1.88–4.59 for Thr/Thr genotype and O.R. 2.68, 95%CI: 1.97–3.64 for ACC haplotype). A significant allelic and genotypic association of T>C (-344) SNP in aldosterone synthase gene (O.R. 1.57, 95%CI: 1.16–2.14 and O.R. 1.81, 95%CI: 1.21–2.71 respectively), and genotypic association of GA genotype of G>A (-1903) in chymase gene (O.R. 2.06, 95%CI: 1.34–3.17) were also observed.ConclusionSNPs Met235Thr in angiotensinogen, T>C (-344) in aldosterone synthase, and G>A (-1903) in chymase genes are significantly associated with diabetic chronic renal insufficiency in Indian patients and warrant replication in larger sample sets. Use of such markers for prediction of susceptibility to diabetes specific renal disease in the ethnically Indian population appears promising.
Antenatal HIV testing in rural eastern Uganda in 2003: incomplete rollout of the prevention of mother-to-child transmission of HIV programme?
Authors: Karamagi Charles AS , Tumwine James K , Tylleskar Thorkild , Heggenhougen Kristian 
Published: May 2006

Abstract

Background
Uganda began to implement the prevention of mother-to-child transmission (PMTCT) of HIV programme in 2000, and by the end of 2003 it had expanded to cover 38 of the 56 districts including Mbale District. However, reports from Mbale Hospital showed that less than 10% of pregnant women accepted antenatal HIV testing. We therefore conducted a study to determine the proportion of pregnant women who tested for HIV and the gaps and barriers in PMTCT implementation.

Methods
The study was a cross sectional household survey of women aged 18 years or more, with children aged one year or less, who resided in Mbale Town or in the surrounding Bungokho County. We also conducted in-depth interviews with six health workers in Mbale Hospital.

Results
In 2003, we interviewed 457 women with a median age of 24 years. The prevalence of antenatal HIV testing was 10 percent. The barriers to antenatal HIV testing were unavailability of voluntary counselling and testing services (44%), lack of HIV counselling (42%) and perceived lack of benefits for HIV infected women and their infants. Primipara (OR 2.6, 95% CI 1.2–5.8), urban dwellers (OR 2.7, 95% CI 1.3–5.8), women having been counselled on HIV (OR 6.2, 95% CI 2.9–13.2), and women with husbands being their primary confidant (OR 2.3, 95% CI 1.0–5.5) were independently associated with HIV testing.

Conclusion
The major barriers to PMTCT implementation were unavailability of PMTCT services, particularly in rural clinics, and poor antenatal counselling and HIV testing services. We recommend that the focus of the prevention of mother-to-child transmission of HIV programme should shift to the district and sub-district levels, strengthen community mobilization, improve the quality of antenatal voluntary counselling and HIV testing services, use professional and peer counsellors to augment HIV counselling, and ensure follow-up care and support for HIV positive women and their infants.
High-throughput screening of cellulase F mutants from multiplexed plasmid sets using an automated plate assay on a functional proteomic robotic workcell
Authors: Hughes Stephen R , Riedmuller Steven B , Mertens Jeffrey A , Li Xin-Liang , Bischoff Kenneth M , Qureshi Nasib , Cotta Michael A , Farrelly Philip J 
Published: May 2006

Abstract

Background
The field of plasmid-based functional proteomics requires the rapid assay of proteins expressed from plasmid libraries. Automation is essential since large sets of mutant open reading frames are being cloned for evaluation. To date no integrated automated platform is available to carry out the entire process including production of plasmid libraries, expression of cloned genes, and functional testing of expressed proteins.

Results
We used a functional proteomic assay in a multiplexed setting on an integrated plasmid-based robotic workcell for high-throughput screening of mutants of cellulase F, an endoglucanase from the anaerobic fungus Orpinomyces PC-2. This allowed us to identify plasmids containing optimized clones expressing mutants with improved activity at lower pH. A plasmid library of mutagenized clones of the celF gene with targeted variations in the last four codons was constructed by site-directed PCR mutagenesis and transformed into Escherichia coli. A robotic picker integrated into the workcell was used to inoculate medium in a 96-well deep well plate, combining the transformants into a multiplexed set in each well, and the plate was incubated on the workcell. Plasmids were prepared from the multiplexed culture on the liquid handler component of the workcell and used for in vitro transcription/translation. The multiplexed expressed recombinant proteins were screened for improved activity and stability in an azo-carboxymethylcellulose plate assay. The multiplexed wells containing mutants with improved activity were identified and linked back to the corresponding multiplexed cultures stored in glycerol. Spread plates were prepared from the glycerol stocks and the workcell was used to pick single colonies from the spread plates, prepare plasmid, produce recombinant protein, and assay for activity. The screening assay and subsequent deconvolution of the multiplexed wells resulted in identification of improved CelF mutants and corresponding optimized clones in expression-ready plasmids.

Conclusion
The multiplex method using an integrated automated platform for high-throughput screening in a functional proteomic assay allows rapid identification of plasmids containing optimized clones ready for use in subsequent applications including transformations to produce improved strains or cell lines.
What Are the Etiology and Epidemiology of Out‐of‐hospital Pediatric Cardiopulmonary Arrest in Ontario, Canada?
Authors: Gerein Richard Bradley , Osmond Martin H. , Stiell Ian G. , Nesbitt Lisa P. , Burns Starla 
Published: May 2006

Abstract
Background:
Pediatric cardiopulmonary arrest (CPA) outside of the hospital has a very high mortality rate.
Objectives:
To evaluate the etiology and initial compromise of pediatric CPA cases in hopes of developing strategies to improve out‐of‐hospital resuscitation.
Methods:
The Ontario Prehospital Advanced Life Support (OPALS) study was a large multicenter initiative to evaluate the impact of emergency medical services (EMS) programs on 17 communities with 40,000 critically ill and injured patients who were older than 11 years. As part of this study, the authors conducted a retrospective observational cohort study that included all children younger than 18 years of age with out‐of‐hospital CPA, during an 11‐year period from 1991–2002. CPA was defined as patient being pulseless, apneic, and requiring chest compressions. Data were collected from ambulance call reports and centralized dispatch data and were reviewed by two independent investigators.
Results:
There were 503 children with CPA in the sample. Mean age was 5.6 years (range, 0–17 yr); 58.4% of patients were male, and 37.8% were younger than 1 year of age. Cardiopulmonary resuscitation (CPR) first was started by a bystander in 32.4% of cases, whereas 66.0% were unwitnessed arrests. Initial rhythms were asystole 77.2% of the time, pulseless electrical activity 16.4% of the time, and ventricular fibrillation or ventricular tachycardia 4% of the time. Annual incidence was 9.1/100,000 children. CPA was witnessed in 34.0% of cases; 80.7% of these were bystander‐witnessed, and 18.1% were EMS‐witnessed. Primary pathogenic cause of arrest was medical in 61.2% of cases, trauma in 37.2% of cases, and indeterminate in 1.6% of cases. Initial underlying physiologic compromise of witnessed arrests was judged to be respiratory in 39.8% of cases, sudden collapse (presumed electrical) in 16.4% of cases, progressive shock in 1.2% of cases, and indeterminate in 42.6% of cases. Presumed etiology was trauma, 37.6%; sudden infant death syndrome (SIDS), 20.3%; and respiratory disease, 11.6%, most commonly. Survival to hospital discharge was 2.0%.
Conclusions:
This is one of the largest population‐based, prospective cohorts of pediatric CPA reported to date, and it reveals that most pediatric arrests are unwitnessed and receive no bystander CPR. Those that are witnessed most often are caused by respiratory arrests or trauma. Trauma, SIDS, and respiratory disease are the most common etiologies overall. These data are vital to planning large resuscitation trials looking at specific interventions (i.e., increasing bystander CPR) and highlight the need for better strategies for prevention and early recognition.
Characteristics of Patients Who Leave Emergency Departments without Being Seen
Authors: Rowe Brian H. , Channan Peter , Bullard Michael , Blitz Sandra , Saunders L. Duncan , Rosychuk Rhonda J. , Lari Harris , Craig William R. , Holroyd Brian R. 
Published: May 2006

Objectives:
Patients leaving the emergency department (ED) without being seen (LWBS) by a physician have become a growing concern in overcrowded EDs. The purpose of this study was to determine the acuity level, reasons, and outcomes of LWBS cases.
Methods:
LWBS patients (or their guardians) from two linked Canadian EDs (one adult, one pediatric), identified during 11 sampling periods of seven days' duration each, were contacted by telephone. Descriptive statistics are provided.
Results:
A total of 711 (4.5%) of 15,660 registered emergency patients left without being seen (50% male; median age, 33 years). Triage‐matched controls waited a median of 87 minutes before seeing a physician. Of the 711 LWBS cases, 512 (72%) were contacted and 498 agreed to participate. The most common major reason for leaving was “fed up with waiting” (44.8%). Overall, 60% of LWBS cases sought medical attention within one week; 14 patients were hospitalized, and one required urgent surgery. Triage level was not associated with the probability of subsequently seeking medical attention (61%, 61%, and 60% in triage levels 3, 4, and 5, respectively). Of the 198 (39%) who did not subsequently seek medical attention, 50 patients (26%) had been triaged as urgent and one patient died six days after ED registration.
Conclusions:
The most common reason for LWBS is impatience during peak ED periods. Many of these patients seek medical care within one week. Complications occurred rarely; however, “high‐risk” patients who leave without being seen do experience adverse health outcomes. Further research is required to examine ways to reduce LWBS cases.
Small Changes in Thyroxine Dosage Do Not Produce Measurable Changes in Hypothyroid Symptoms, Well-Being, or Quality of Life: Results of a Double-Blind, Randomized Clinical Trial
Authors: Walsh John P. , Ward Lynley C. , Burke Valerie , Bhagat Chotoo I. , Shiels Lauren , Henley David , Gillett Melissa J. , Gilbert Rhonda , Tanner Melissa , Stuckey Bronwyn G. A. 
Published: May 2006

Abstract
Context: In patients with primary hypothyroidism, anecdotal evidence suggests that well-being is optimized by fine adjustment of T4 dosage, aiming for a serum TSH concentration in the lower reference range. This has not been tested in a clinical trial.
Objective: Our objective was to test whether adjustment of T4 dosage aiming for a serum TSH concentration less than 2 mU/liter improves well-being compared with a serum TSH concentration in the upper reference range.
Design: We conducted a double-blind, randomized clinical trial with a crossover design.
Participants: Fifty-six subjects (52 females) with primary hypothyroidism taking T4 (≥100 μg/d) with baseline serum TSH 0.1–4.8 mU/liter participated.
Interventions: Each subject received three T4 doses (low, middle, and high in 25-μg increments) in random order.
Outcome Measures: Outcome measures included visual analog scales assessing well-being (the primary endpoint) and hypothyroid symptoms, quality of life instruments (General Health Questionnaire 28, Short Form 36, and Thyroid Symptom Questionnaire), cognitive function tests, and treatment preference.
Results: Mean (± sem) serum TSH concentrations were 2.8 ± 0.4, 1.0 ± 0.2, and 0.3 ± 0.1 mU/liter for the three treatments. There were no significant treatment effects on any of the instruments assessing well-being, symptoms, quality of life, or cognitive function and no significant treatment preference.
Conclusions: Small changes in T4 dosage do not produce measurable changes in hypothyroid symptoms, well-being, or quality of life, despite the expected changes in serum TSH and markers of thyroid hormone action. These data do not support the suggestion that the target TSH range for the treatment of primary hypothyroidism should differ from the general laboratory range.
Analyzing the Functional and Structural Consequences of Two Point Mutations (P94L and A368D) in the CYP11B1 Gene Causing Congenital Adrenal Hyperplasia Resulting from 11-Hydroxylase Deficiency
Authors: Krone Nils , Grischuk Yulia , Müller Marina , Volk Ruth Elisabeth , Grötzinger Joachim , Holterhus Paul-Martin , Sippell Wolfgang G. , Riepe Felix G. 
Published: May 2006

AbstractContext: Congenital adrenal hyperplasia is a group of autosomal recessive inherited disorders of steroidogenesis. The deficiency of steroid 11-hydroxylase (CYP11B1) resulting from mutations in the CYP11B1 gene is the second most frequent cause.Objective: We studied the functional and structural consequences of two CYP11B1 missense mutations, which were detected in a 1.8-yr-old boy with acne and precocious pseudopuberty, to prove their clinical relevance and study their impact on CYP11B1 function.Results: The in vitro expression studies in COS-7 cells revealed an almost complete absence of CYP11B1 activity for the P94L mutant to 0.05% for the conversion of 11-deoxycortisol to cortisol. The A368D mutant severely reduced the CYP11B1 enzymatic activity to 1.17%. Intracellular localization studies by immunofluorescence revealed that the mutants were correctly localized. Introducing these mutations in a three-dimensional model structure of the CYP11B1 protein provides a possible explanation for the effects measured in vitro. We hypothesize that the A368D mutation interferes with structures important for substrate specificity and heme iron binding, thus explaining its major functional impact. However, according to structural analysis, we would expect only a minor effect of the P94L mutant on 11-hydroxylase activity, which contrasts with the observed major effect of this mutation both in vitro and in vivo.Conclusion: Analyzing the in vitro enzyme function is a complementary procedure to genotyping and a valuable tool for understanding the clinical phenotype of 11-hydroxylase deficiency. This is the basis for accurate genetic counseling, prenatal diagnosis, and treatment. Moreover, the combination of in vitro enzyme function and molecular modeling provides valuable insights in cytochrome P450 structural-functional relationships, although one must be aware of the limitations of in silico-based methods.
Structure of Halo-toxin Produced by Phytopathogenic Bacterium, Pseudomonas syringae pv. mori
Authors: Kajimoto Tetsuya , Yokomizo Kazumi , Yahiro Kiyoshi , Umeda Toshiko , Shoji Shozo , Kubota Yukiho , Shibata Motoo , Takahashi Kokichi , Nohara Toshihiro 
Published: May 2006

Abstract
Halo-toxin was isolated from the incubated medium of pseudomonas syringae pv. mori which causes halo bright disease against the leaves of mulberry trees. The structure of this compound was revealed to be Pro-Phe-Pro-Gly-Pro-Ile by spectroscopic means and amino acid sequence analysis.
Redox System of Palladium–Trimethyl Ester of Coenzyme PQQ
Authors: Hirao Toshikazu , Murakami Toshihide , Ohno Mitsuru , Ohshiro Yoshiki 
Published: May 2006

Abstract
Trimethyl ester of coenzyme PQQ (PQQTME) and PdCl2 constitute an effective redox system on treatment with terminal olefin in DMF-H2O, which permits the PdCl2-PQQTME catalyzed Wacker oxidation reaction under oxygen.