bluuebunny/crossref_metadata_2025_split huggingface dataset:
Initial uptake and evidence of safe prescribing practice with Buproprion (Zyban®)
Authors: Williams D. , Bennett K. , Heery A. , Feely J. 
Published: May 2004

AbstractPurposeTo study the effect of safety concerns and the introduction of freely available nicotine replacement therapy (NRT) on the prescribing of Buproprion within the General Medical Services (GMS) scheme in Ireland.MethodsUsing the state‐supported GMS prescription database in Ireland, we identified 8166 patients who were prescribed Buproprion and 18 450 patients who were prescribed NRT over a 12‐month‐period.ResultsA decline in the prescribing of Buproprion was noted which coincided with concerns regarding the safety of the drug but which preceded the introduction of NRT to the GMS. Furthermore, patients who were prescribed Buproprion were less likely to be co‐prescribed potentially interacting drugs (odds ratio (OR): 0.48, 95% confidence intervals (CI): 0.42, 0.54) or drugs known to reduce seizure threshold (OR: 0.63, 95% CI: 0.6, 0.67) indicating good prescribing practice. Patients aged 65 years or more were less likely to be prescribed any form of smoking cessation therapy compared with those aged <65 years (OR: 0.23, 95% CI: 0.22–0.24) indicating that such therapy was targeted at those most likely to benefit.ConclusionsWe provide evidence that prescribers exercised caution in the prescription of Buproprion and were likely to have been influenced both by the safety concerns and the introduction of freely available NRT to the GMS population. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis, characterization, and biological activity of [2‐oxo‐2‐(4‐acetyl) phenyl amino] ethylene methacrylate and its derivatives
Authors: Erol Ibrahim 
Published: May 2004

AbstractA new type of methacrylate monomer, [2‐oxo‐2‐(4‐acetyl) phenyl amino] ethylene methacrylate (APEMA), was synthesized. The oxime, 2,4‐dinitrophenylhydrazone, and thiosemicarbazone derivatives of poly{[2‐oxo‐2‐(4‐acetyl) phenyl amino] ethylene methacrylate} [poly(APEMA)] were prepared with hydroxylamine hydrochloride, 2,4‐dinitrophenylhydrazine, and thiosemicarbazone hydrochloride, respectively. The radical homopolymerization of APEMA was performed at 65 °C in a 1,4‐dioxane solution with benzoyl peroxide as an initiator. The monomer and its homopolymer were characterized with Fourier transform infrared and NMR techniques. The thermal stabilities of poly(APEMA) and its derivatives were investigated with thermogravimetric analysis and differential scanning calorimetry. The ultraviolet stability of the polymers were compared. The solubility and inherent viscosity of the polymers were also determined. The number‐average and weight‐average molecular weights and polydispersity index of the polymers were determined with gel permeation chromatography. The antibacterial and antifungal effects of the monomer and the polymer and its derivatives were also investigated on various bacteria and fungi. The activation energies of the thermal degradation of the polymers were calculated with the Ozawa method. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3157–3169, 2004
Preparation and characterization of multifunctional maleimide macromonomers and their cured resins
Authors: Liu Ying‐Ling , Wang Yao‐Hsuan 
Published: May 2004

AbstractMultifunctional compounds with pendent and terminal maleimide groups were prepared through the reaction of 4‐maleimidobenzoic acid and 5‐maleimidoisophthalic acid with diglycidyl ether of bisphenol A. The ratios of the pendent maleimide groups to the terminal maleimide groups in the obtained compounds were varied to tailor the chain length and properties of the maleimide compounds. The maleimide group ratios, determined from differential scanning calorimetry, showed good coincidence with the values calculated from the charged monomer amounts. The good solubility and low softening points of the maleimide compounds indicated their good processability. High glass‐transition temperatures (220 °C) were observed for the cured resins because of the relatively high crosslinking density. The curing reaction, thermal stability, and degradation behavior of the resins were also studied with differential scanning calorimetry and thermogravimetric analysis. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3178–3188, 2004
Synthesis of novel polypyromellitimides with n‐alkyloxy side chains and their liquid‐crystal aligning property
Authors: Lee Seong Jun , Jung Jin Chul , Lee Seung Woo , Ree Moonhor 
Published: May 2004

AbstractNew well‐defined brush polypyromellitimides with n‐octyloxy and n‐dodecyloxy side chains were prepared by two‐step polycondensations of 3,6‐di(n‐alkyloxy)pyromellitic dianhydrides with various conventional aromatic diamines. Their structures and properties were investigated and compared with those of polyimides without the side chains. The alkyloxylated poly(amic acid)s had inherent viscosities of 0.45–1.09 dL/g. The polyimides showed enhanced solubility in organic solvents and had layered structures in the solid state. As the side‐chain length increased from n‐octyloxy to n‐dodecyloxy, the extent of layered structure formation increased, whereas the glass‐transition temperature and thermal resistance decreased. As for the liquid‐crystal (LC) aligning ability measured with 4‐n‐pentyl‐4′‐cyanobiphenyl on rubbed thin‐film surfaces, all the side‐chain polyimides revealed homogeneous LC alignment parallel to the rubbing direction with distinctively higher pretilt angles than those of the polyimides without the side chains. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3130–3142, 2004
Structure and properties of polyimide films during a far‐infrared‐induced imidization process
Authors: Xu Yi‐Kun , Zhan Mao‐Sheng , Wang Kai 
Published: May 2004

AbstractThe conversion of poly(amic acid) into polyimide (PI) was achieved with far‐infrared radiation (FIR) and conventional thermal treatments. The structure and properties of PI films during different stages of imidization were studied with Fourier transform infrared spectroscopy, weight‐loss analysis during imidization, tensile property measurements, and dynamic mechanical thermal analysis. The effects of the imidization degree, postimidization, and solvent on the thermal and mechanical properties of PI films were quantitatively investigated. The corresponding structural changes were also examined. The experimental results showed that the imidization process proceeded more quickly and more completely in an FIR oven than in a conventional oven. A prolonged FIR treatment at a lower temperature (25–100 °C) accelerated the imidization process. The tensile stress–strain curves had a fanlike distribution with the development of the FIR imidization process and a fishtail distribution with conventional thermal imidization. During FIR imidization, the best tensile properties were obtained at 340 °C, and thermooxidative degradation occurred at about 420 °C. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2490–2501, 2004
Ethylenediamine as a liquid chemical reagent to probe hydrogen bonding and host‐guest interactions with crown ethers in an ion trap tandem mass spectrometer
Authors: Wu Hui‐Fen , Lin Pei‐Yi 
Published: May 2004

AbstractEthylenediamine (EDA) was used as a novel liquid chemical reagent to probe hydrogen bonding and host‐guest interactions with crown ether derivatives in an ion trap mass spectrometer (ITMS). Selective ion/molecule reaction product ions were generated by reactions of EDA with oxygenated and aza‐crown ethers. For the oxygenated crown ethers, glycols and dimethylglycols, ion/molecule reactions led to the formation of the protonated molecules ([M+H]+) and adduct ions including [M+30]+, [M+44]+ and [M+61]+. The aza‐crown ethers produced [M+H]+, [M+13]+ and [M+27]+ ions. Collisionally activated dissociation (CAD) experiments were applied to probe the binding strength of these ion/molecule reaction products. CAD results indicated that all these hydrogen‐bonding complexes are weakly bound except for the [M+44]+ ion of 18‐crown‐6, since all the complexes dissociate to the protonated polyether and/or protonated EDA. Fragmentation of the [M+H]+ ions under CAD conditions indicates the extensive covalent bond cleavage of the protonated crown ether skeleton. Copyright © 2004 John Wiley & Sons, Ltd.
Analytical characterization of a facile porous polymer monolithic trypsin microreactor enabling peptide mass mapping using mass spectrometry
Authors: Palm Anders K. , Novotny Milos V. 
Published: May 2004

AbstractA simple and rapid single‐step method is presented to fabricate an enzyme reactor using trypsin immobilized on a macroporous polymer monolith. A reactor produced in a capillary format is ready to use within 1 h of preparation. The monomers making up the monolith, includingN‐acryloxysuccinimide for covalent immobilization of the enzyme, are mixed with trypsin and introduced into the column by capillary force for polymerization/immobilization. The enzyme activity from column‐to‐column is reproducible below 5% relative standard deviation (RSD), while the reactor is durable for at least 20 weeks when stored at room temperature. The apparent kinetic constants Vmaxand Kmare of value similar to those obtained by free trypsin in solution. Enzymatic digestion of proteins was shown to be feasible on a time‐scale of seconds and submicromolar concentrations enabling peptide mass mapping by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. Copyright © 2004 John Wiley & Sons, Ltd.
Using the Impact of Event Scale to Evaluate Psychological Response to Being a Phenylketonuria Gene Carrier
Authors: Read Catherine Y. 
Published: May 2004

AbstractThe birth of a child with phenylketonuria (PKU) is almost always a shock to the parents, who are faced with the realities of caring for a child with special needs and the need to cope with the realization that they are obligate carriers of the responsible gene. The Impact of Event Scale (IES) was used to assess the psychological impact of being a PKU gene carrier on 83 parents of children with PKU. IES scores decreased significantly from the time of initial diagnosis of PKU to the current time. The magnitude of the psychological impact did not correlate with the age of the parent, the number of years since the diagnosis of PKU, or the health or development of the child. As more tests become available for detecting the presence of disease‐related genes, instruments such as the IES may prove useful in the evaluation of psychological responses to genetic information.
Intraoperative Hyperglycemia during Infant Cardiac Surgery Is Not Associated with Adverse Neurodevelopmental Outcomes at 1, 4, and 8 Years
Authors: de Ferranti Sarah , Gauvreau Kimberlee , Hickey Paul R. , Jonas Richard A. , Wypij David , du Plessis Adre , Bellinger David C. , Kuban Karl , Newburger Jane W. , Laussen Peter C. 
Published: May 2004

Background
It is unknown whether intraoperative hyperglycemia in infants is associated with worse neurodevelopmental outcomes after low-flow cardiopulmonary bypass (LF), deep hypothermic circulatory arrest (CA), or both.

Methods
In a database review of a prospective trial of 171 infants undergoing arterial switch for D-transposition of the great arteries who were randomly assigned to predominantly LF or CA, glucose was measured after induction (T1), 5 min after cardiopulmonary bypass onset (T2), at the onset of CA or LF (T3), 5 min after CPB resumption (T4), at rewarming to 32 degrees C (T5), 10 min after cardiopulmonary bypass weaning (T6), and 90 min after CA or LF (T7). Outcomes included seizures, electroencephalographic findings, and neurodevelopmental evaluation at 1, 4, and 8 yr.

Results
Glucose concentrations were affected by support strategy and age at surgery. Lower glucose in the entire group at T6-T7 tended to predict electroencephalographic seizures (P = 0.06 and P = 0.007) but was not related to clinical seizures. Within the predominantly CA group, higher glucose did not correlate with worse outcomes. Rather, it was associated with more rapid electroencephalographic normalization of "close burst" and "relative continuous" activity at all times except T2 (P < or = 0.03), a finding more pronounced in infants aged 7 days old or younger. Intraoperative serum glucose concentrations were unrelated to neurodevelopmental outcomes at ages 1, 4, and 8 yr.

Conclusions
Low glucose after cardiopulmonary bypass tended to relate to electroencephalographic seizures and slower electroencephalogram recovery, independent of CA duration. High glucose concentrations were not associated with worse neurodevelopmental outcomes. Avoiding hypoglycemia may be preferable to restricting glucose in infants undergoing heart surgery.
A Response Surface Analysis of Propofol–Remifentanil Pharmacodynamic Interaction in Volunteers
Authors: Kern Steven E. , Xie Guoming , White Julia L. , Egan Talmage D. 
Published: May 2004

Background
Characterizing drug interactions using a response surface allows for the determination of the interaction over a complete range of clinically relevant concentrations. Gathering the data necessary to create this surface is difficult to do in a clinical setting and requires the use of volunteer experiments with surrogate noxious stimuli to adequately control the process for data collection. The pharmacodynamic synergy of opioids and hypnotics was investigated using a volunteer study paradigm.

Methods
Twenty-four volunteer subjects (12 male, 12 female) were studied using computer-controlled infusions of propofol and remifentanil to create an increasing staircase drug concentration profile in each subject. Three different drug delivery profiles were administered to subjects, one with a single agent and two with combinations of propofol and remifentanil. At each plateau of the staircase profile, drug effect was assessed using four surrogate measures: Observer Assessment of Alertness/Sedation score, tibial pressure algometry, electrical tetany, and response to laryngoscopy. Response surfaces were developed that mapped the interaction of propofol and remifentanil to these surrogate effect measures in all subjects. An interaction parameter was used to assess whether these two drugs behave synergistically to blunt response to noxious stimuli.

Results
The response surfaces showed considerable synergy between remifentanil and propofol for blunting response to the noxious stimuli. The interaction index, a measure of synergy, was 8.2 and 14.7 for response to algometry and tetany, respectively (P < 0.001), and 5.1 and 33.2 for sedation and laryngoscopy, respectively (P < 0.001), using the Greco interaction model. The surrogate stimuli mapped to clinically relevant concentrations for these agents in combination.

Conclusions
The response surface models reveal the tremendous synergy between remifentanil and propofol. The surface morphologic features give some indication of the relative contribution of sedation and analgesia to blunting subject response. Further, the results of this investigation validate the volunteer study paradigm and use of surrogate effect measures for its clinical relevance.
Determination of the Pharmacodynamic Interaction of Propofol and Remifentanil during Esophagogastroduodenoscopy in Children
Authors: Drover David R. , Litalien Catherine , Wellis Vinit , Shafer Steven L. , Hammer Gregory B. 
Published: May 2004

Background
Propofol is commonly used to anesthetize children undergoing esophagogastroduodenoscopy. Opioids are often used in combination with propofol to provide total intravenous anesthesia. Because both propofol and remifentanil are associated with rapid onset and offset, the combination of these two drugs may be particularly useful for procedures of short duration, including esophagogastroduodenoscopy. The authors previously demonstrated that the median effective concentration (C50) of propofol during esophagogastroduodenoscopy in children is 3.55 microg/ml. The purpose of this study was to describe the pharmacodynamic interaction of remifentanil and propofol when used in combination for esophagogastroduodenoscopy in pediatric patients.

Methods
The authors studied 32 children aged between 3 and 10 yr who were scheduled to undergo esophagogastroduodenoscopy. Propofol was administered via a target-controlled infusion system using the STANPUMP software based on a pediatric pharmacokinetic model. Remifentanil was administered as a constant rate infusion of 25, 50, and 100 ng.kg(-1).min(-1) to each of three study groups, respectively. A sigmoid Emax model was developed to describe the interaction of remifentanil and propofol.

Results
There was a positive interaction between remifentanil and propofol when used in combination. The concentration of propofol alone associated with 50% probability of no response was 3.7 microg/ml (SE, 0.4 microg/ml), and this was decreased to 2.8 microg/ml (SE, 0.1 microg/ml) when used in combination with remifentanil.

Conclusion
A remifentanil infusion of 25 ng.kg(-1).min(-1) reduces the concentration of propofol required for adequate anesthesia for esophagogastroduodenoscopy from 3.7 to 2.8 microg/ml. Increasing the remifentanil infusion yields minimal additional decrease in propofol concentration and may increase the risk of side effects.
Evidence for Development of Capillary Leak Syndrome Associated with Cardiopulmonary Bypass in Pediatric Patients with the Homozygous C4A Null Phenotype
Authors: Zhang Shihai , Wang Shouyong , Yao Shanglong 
Published: May 2004

Background
The mechanism of postoperative capillary leak syndrome related to cardiopulmonary bypass (CPB) is unknown. The authors hypothesized that C4 gene polymorphism might be involved in the development of the syndrome because complement activation is associated with CPB and protamine administration, and the two isotypes of C4 (C4A and C4B) differ in their biochemical and functional properties after activation.

Methods
One hundred fifty-six pediatric patients referred for elective cardiac surgery with CPB were included in the study. C4 isotype studies were performed in plasma samples obtained before surgery, with use of agarose gel immunofixation and crossed immunoelectrophoresis. Five possible C4 phenotype groups were observed, which were abbreviated as follows: (1) AABB = no detectable null alleles, (2) A0BB = a single null allele (heterozygous) at the C4A locus, (3) 00BB = a homozygous C4A null allele, (4) AAB0 = a single null allele (heterozygous) at the C4B locus, and (5) AA00 = a homozygous C4B null allele. The patients were classified into five groups according to their C4 phenotypes. Before CPB and at 1 h after CPB, plasma protein was measured with a biuret test kit. Plasma colloid osmotic pressure was determined with a membrane osmometer. Evans blue dye was used to measure plasma volume, serum protein, intravenous protein pool, and transvascular escape rate of Evans blue dye.

Results
Of 156 pediatric patients enrolled, 80 were assigned to the AABB group, 28 were assigned to the A0BB group, 7 were assigned to the 00BB group, 31 were assigned to the AAB0 group, and 10 were assigned to the AA00 group, according to their C4 phenotypes. At 1 h after CPB, serum protein concentrations averaged 3.6 +/- 0.4 g/dl in patients with the 00BB C4 phenotype; this value was significantly lower (P < 0.01) than that in patients with other C4 phenotypes. The changes of intravenous protein pool and colloid osmotic pressure were comparable with the change in serum protein concentration. At 1 h after CPB, the transvascular escape rate of Evans blue dye averaged 11.5 +/- 1.3%/h in patients with the 00BB C4 phenotype; this value was significantly higher (P < 0.01) than that in patients with other C4 phenotypes.

Conclusions
In this study, capillary leak syndrome induced by CPB occurred only in patients with the homozygous C4A null phenotype.
Injuries and Liability Related to Central Vascular Catheters
Authors: Domino Karen B. , Bowdle T. Andrew , Posner Karen L. , Spitellie Pete H. , Lee Lorri A. , Cheney Frederick W. 
Published: May 2004

Background
To assess changing patterns of injury and liability associated with central venous or pulmonary artery catheters, the authors analyzed closed malpractice claims for central catheter injuries in the American Society of Anesthesiologists Closed Claims database.

Methods
All claims for which a central catheter (i.e., central venous or pulmonary artery catheter) was the primary damaging event for the injury were compared with the rest of the claims in the database. Central catheter complications were defined as being related to vascular access or catheter use or maintenance. Statistical analysis was performed using the chi-square test, Fisher exact test, or Z test (proportions) and the Kolmogorov-Smirnov test (payments).

Results
The database included 110 claims for injuries related to central catheters (1.7% of 6,449 claims). Claims for central catheter injuries had a higher severity of injury, with an increased proportion of death (47%) compared with other claims in the database (29%, P < 0.01). The most common complications were wire/catheter embolus (n = 20), cardiac tamponade (n = 16), carotid artery puncture/cannulation (n =16), hemothorax (n =15), and pneumothorax (n =14). Cardiac tamponade, hemothorax, and pulmonary artery rupture had a higher proportion of death (P < 0.05) compared with the rest of the central catheter injures. The proportion of claims for vascular access injury increased (47% to 84%) and use/maintenance injury decreased (53% to 16%) in 1994-1999 compared with 1978-1983 (P < 0.05).

Conclusions
Claims related to central catheters had a high severity of patient injury. The most common complications causing injury were wire/catheter embolus, cardiac tamponade, carotid artery puncture/cannulation, hemothorax, and pneumothorax.
Measurement of Oxygen Uptake and Carbon Dioxide Elimination Using the Bymixer
Authors: Rosenbaum Abraham , Kirby Christopher , Breen Peter H. 
Published: May 2004

Background
The authors have developed a new clinical bymixer that bypasses a constant fraction of gas flow through a mixing arm. A separate bymixer was interposed in the expiratory and inspiratory limbs of the ventilation circuit to measure mixed gas fractions. By utilizing nitrogen conservation, the clinical bymixer allows the determination of airway carbon dioxide elimination (VCO2) and oxygen uptake (VO2), whenever basic expired flow and gas monitoring measurements are used for the patient. Neither an expiratory exhaust gas collection bag nor expensive, complex equipment are needed. This study tested the accuracy of airway bymixer-flow measurements of VCO2 and VO2 in a new bench apparatus.

Methods
The authors compared airway bymixer-flow measurements of VCO2 and VO2 over a range of reference values generated by ethanol combustion in a new metabolic lung simulator, which was ventilated by a volume-cycled respirator. An airway humidity and temperature sensor permitted standard temperature and pressure, dry, correction of airway VCO2 and VO2.

Results
Bymixer-flow airway measurements of VCO2 and VO2 correlated closely (R2 = 0.999 and 0.998, respectively) with the stoichiometric values generated by ethanol combustion. Limits of agreement for VCO2 and VO2 were 0.1 +/- 4.7 and 1.1 +/- 5.7%, respectively. The average (+/- SD) percent error for airway VCO2 (compared with the stoichiometric value) was 0.1 +/- 2.4%. The same error for airway VO2 was 1.1 +/- 2.9%.

Conclusions
The new clinical bymixer, plus basic expired flow and gas fraction measurements, generated clinically accurate determinations of VCO2 and VO2. These measurements are helpful in the assessment of metabolic gas exchange in the critical care unit. In contrast to using the gas collection bag or complex metabolic monitor, the bymixer should measure mixed gas concentrations in the inspired or expired limb of the common anesthesia circle ventilation circuit.