bluuebunny/crossref_metadata_2025 huggingface dataset:
The accuracy of image-free computer navigation in the placement of the femoral component of the Birmingham Hip Resurfacing
Authors: Davis E. T. , Gallie P. , Macgroarty K. , Waddell J. P. , Schemitsch E.
Published: April 2007

A cadaver study using six pairs of lower limbs was conducted to investigate the accuracy of computer navigation and standard instrumentation for the placement of the Birmingham Hip Resurfacing femoral component. The aim was to place all the femoral components with a stem-shaft angle of 135°.

The mean stem-shaft angle obtained in the standard instrumentation group was 127.7° (120° to 132°), compared with 133.3° (131° to 139°) in the computer navigation group (p = 0.03). The scatter obtained with computer-assisted navigation was approximately half that found using the conventional jig.

Computer navigation was more accurate and more consistent in its placement of the femoral component than standard instrumentation. We suggest that image-free computer-assisted navigation may have an application in aligning the femoral component during hip resurfacing.
The initial stability and contact mechanics of a press-fit resurfacing arthroplasty of the hip
Authors: Udofia I. , Liu F. , Jin Z. , Roberts P. , Grigoris P.
Published: April 2007

Finite element analysis was used to examine the initial stability after hip resurfacing and the effect of the procedure on the contact mechanics at the articulating surfaces. Models were created with the components positioned anatomically and loaded physiologically through major muscle forces. Total micromovement of less than 10 μm was predicted for the press-fit acetabular components models, much below the 50 μm limit required to encourage osseointegration. Relatively high compressive acetabular and contact stresses were observed in these models. The press-fit procedure showed a moderate influence on the contact mechanics at the bearing surfaces, but produced marked deformation of the acetabular components. No edge contact was predicted for the acetabular components studied.

It is concluded that the frictional compressive stresses generated by the 1 mm to 2 mm interference-fit acetabular components, together with the minimal micromovement, would provide adequate stability for the implant, at least in the immediate post-operative situation.
Balloon kyphoplasty as a single or as an adjunct procedure for the management of symptomatic vertebral haemangiomas
Authors: Hadjipavlou A. , Tosounidis T. , Gaitanis I. , Kakavelakis K. , Katonis P.
Published: April 2007

Vertebral haemangiomas are usually asymptomatic and discovered fortuitously during imaging. A small proportion may develop variable degrees of pain and neurological deficit. We prospectively studied six patients who underwent eight surgical procedures on 11 vertebral bodies. There were 11 balloon kyphoplasties, six lumbar and five thoracic. The mean follow-up was 22.3 months (12 to 36). The indications for operation were pain in four patients, severe back pain with Frankel grade C paraplegia from cord compression caused by soft-tissue extension from a thoracic vertebral haemangioma in one patient, and acute bleeding causing Frankel grade B paraplegia from an asymptomatic vascular haemangioma in one patient. In four patients the exhibited aggressive vascular features, and two showed lipomatous, non-aggressive, characteristics. One patient who underwent a unilateral balloon kyphoplasty developed a recurrence of symptoms from the non-treated side of the vertebral body which was managed by a further similar procedure.

Balloon kyphoplasty was carried out successfully and safely in all patients; four became asymptomatic and two showed considerable improvement. Neurological recovery occurred in all cases but bleeding was greater than normal. To avoid recurrence, complete obliteration of the lesion with bone cement is indicated. For acute bleeding balloon kyphoplasty should be combined with emergency decompressive laminectomy. For intraspinal extension with serious neurological deficit, a combination of balloon kyphoplasty with intralesional alcohol injection is effective.
Fractures of the distal humeral articular surface
Authors: Watts A. C. , Morris A. , Robinson C. M.
Published: April 2007

Fractures of the distal humeral articular surface which do not involve the medial and lateral columns are often more extensive than is apparent from plain radiographs. This retrospective study describes the epidemiology of this injury using modern classification systems and compares pre-operative radiography with operative findings. The study group included 79 patients with a mean age of 47 years (13 to 91). The annual incidence was 1.5 per 100 000 population, and was highest in women over the age of 60. The majority of the fractures (59; 75%) were sustained in falls from standing height. Young males tended to sustain more high-energy injuries with more complex fracture patterns. In 24% of cases (19) there was a concomitant radial head fracture. Classification from plain radiographs often underestimates the true extent of the injury and computed tomography may be of benefit in pre-operative planning, especially in those over 60 years of age.
The anabolic and catabolic responses in bone repair
Authors: Little D. G. , Ramachandran M. , Schindeler A.
Published: April 2007

The literature on fracture repair has been reviewed. The traditional concepts of delayed and nonunion have been examined in terms of the phased and balanced anabolic and catabolic responses in bone repair. The role of medical manipulation of these inter-related responses in the fracture healing have been considered.
Reverse V osteotomy of the distal humerus for the correction of cubitus varus
Authors: Yun Y.-H. , Shin S.-J. , Moon J.-G.
Published: April 2007

We reviewed 22 children with cubitus varus who had been treated by a reverse V osteotomy and fixation by cross-pinning and wiring. The mean pre-operative humeral-elbow-wrist angle was −16.9° (−25° to +9°) and at the latest follow-up it was +7.3° (−2° to +14°). No child had a lateral prominence greater than 5 mm after correction. An excellent result was achieved in 20 children and a good result in two. We believe that this osteotomy has the advantages of better inherent stability, the avoidance of a prominent lateral condyle after correction and firm fixation allowing early movement.
Endoprosthetic replacement of the distal femur for bone tumours
Authors: Myers G. J. C. , Abudu A. T. , Carter S. R. , Tillman R. M. , Grimer R. J.
Published: April 2007

We investigated whether improvements in design have altered the outcome for patients undergoing endoprosthetic replacement of the distal femur after resection of a tumour. Survival of the implant and ‘servicing’ procedures have been documented using a prospective database, review of the design of the implant and case records. In total, 335 patients underwent a distal femoral replacement, 162 having a fixed-hinge design and 173 a rotating-hinge. The median age of the patients was 24 years (interquartile range 17 to 48).

A total of 192 patients remained alive with a mean follow-up of 12 years (5 to 30). The risk of revision for any reason was 17% at five years, 33% at ten years and 58% at 20 years. Aseptic loosening was the main reason for revision of the fixed-hinge knees while infection and fracture of the stem were the most common for the rotating-hinge implant. The risk of revision for aseptic loosening was 35% at ten years with the fixed-hinge knee, which has, however, been replaced by the rotating-hinge knee with a hydroxyapatite collar. The overall risk of revision for any reason fell by 52% when the rotating-hinge implant was used.

Improvements in the design of distal femoral endoprostheses have significantly decreased the need for revision operations, but infection remains a serious problem. We believe that a cemented, rotating-hinge prosthesis with a hydroxyapatite collar offers the best chance of long-term survival of the prosthesis.
The prophylaxis and treatment of heterotopic ossification following lower limb arthroplasty
Authors: Board T. N. , Karva A. , Board R. E. , Gambhir A. K. , Porter M. L.
Published: April 2007

Heterotopic ossification following joint replacement in the lower limb occurs in 3% to 90% of cases. Higher grades of heterotopic ossification can result in significant limitation of function and can negate the benefits of joint replacement. The understanding of the pathophysiology of this condition has improved in recent years. It would appear to be related to a combination of systemic and local factors, including over-expression of bone morphogenetic protein-4. There is currently little evidence to support the routine use of prophylaxis for heterotopic ossification in arthroplasty patients, but prophylaxis is recommended by some for high-risk patients. Radiotherapy given as one dose of 7 Gy to 8 Gy, either pre-operatively (< four hours before) or post-operatively (within 72 hours of surgery), appears to be more effective than indometacin therapy (75 mg daily for six weeks). In cases of prophylaxis against recurrent heterotopic ossification following excision, recent work has suggested that a combination of radiotherapy and indometacin is effective. Advances in our understanding of this condition may permit the development of newer, safer treatment modalities.
Aptamers Evolved from Cultured Cancer Cells Reveal Molecular Differences of Cancer Cells in Patient Samples
Authors: Shangguan Dihua , Cao Zehui Charles , Li Ying , Tan Weihong
Published: April 2007

Background: Molecular-level differentiation of neoplastic cells is essential for accurate and early diagnosis, but effective molecular probes for molecular analysis and profiling of neoplastic cells are not yet available. We recently developed a cell-based SELEX (systematic evolution of ligands by exponential enrichment) strategy to generate aptamers (designer DNA/RNA probes) as molecular probes to recognize neoplastic cells.

Methods: We tested 6 cell-SELEX–generated aptamers with equilibrium dissociation constants in the nanomolar to subnanomolar range: sgd5, selected from Toledo cells, a human diffuse large-cell lymphoma cell line (B-cell), and sgc8, sgc3, sgc4, sgd2, and sgd3 from CCRF-CEM cells, a human precursor T cell acute lymphoblastic leukemia (T-ALL) cell line. Aptamers were labeled with fluorescein isothiocyanate fluorophores and then used to recognize, by flow cytometric analysis, neoplastic cells in cultured hematopoietic cell lines and clinical samples.

Results: Aptamer sgd5 recognized only its target cells. Aptamers sgc3, sgd2, sgd3, sgc4, and sgc8, selected from a T-cell leukemia cell line, identified all of the cultured T-cell leukemia cell lines with relatively high fluorescence intensity. Aptamers sgc8, sgc3, and sgd3 showed good selectivity toward T-ALL cells and almost no binding to normal hematopoietic cells or lymphoma and myeloma cells. Selected aptamers also detected targets on the cell membranes of neoplastic cells in patient samples.

Conclusions: Aptamers selected against cultured neoplastic cells can effectively be used as molecular probes for recognition of neoplastic cells in patient samples. Cell-based aptamer selection can be used to generate aptamer probes to obtain molecular signatures of neoplastic cells in patient samples.
Comparison of Bromcresol Green and Agarose Protein Electrophoresis for Quantitation of Serum Albumin in Multiple Myeloma
Authors: Snozek Christine LH , Saenger Amy K , Greipp Philip R , Bryant Sandra C , Kyle Robert A , Rajkumar S Vincent , Katzmann Jerry A
Published: April 2007

Background: The International Staging System for multiple myeloma has increased the importance of accurate measurement of serum albumin. Two common albumin assays, bromcresol green (BCG) and agarose gel protein electrophoresis (PEL), frequently yield discordant results, creating confusion regarding which assay is superior for use in myeloma.

Methods: We measured albumin by BCG on a Roche Modular system, by PEL with a Helena SPIFE SPE Vis agarose gel, and by immunonephelometry performed on a Dade Behring BNII nephelometer. BCG and PEL were used to measure albumin in 5777 patient samples, and all 3 methods were used in an additional 252 samples. The clinical impact was assessed on 698 myeloma patient samples.

Results: For sera with zero/low monoclonal immunoglobulin protein (M)-spike (0 to <15 g/L), results for both BCG and PEL correlated well to nephelometry, although median PEL results were 8 g/L lower than corresponding BCG measurements. Correlation between PEL and nephelometry or BCG diminished with increasing M-spike, with PEL eventually overestimating albumin compared with both other assays. IgG and IgA M-spikes showed significantly different effects on albumin discordance. For 35% of myeloma patients, discrepancy between BCG and PEL had a potentially clinically significant effect on staging, but no difference in group survival was found.

Conclusions: Both BCG and PEL correlate well to nephelometry in sera with zero/low M-spikes. In the presence of larger M-spikes, PEL correlates poorly to nephelometry or BCG, whereas BCG compares well with nephelometry regardless of M-spike. Thus, albumin measurement can be performed reliably in myeloma patient sera by use of inexpensive, automated BCG assays.
Genotype–Environment Interactions: Cognitive Aging and Social Factors
Authors: Reynolds Chandra A. , Gatz Margaret , Berg Stig , Pedersen Nancy L.
Published: April 2007

The possibility of genotype–environment interaction for memory performance and change was examined in 150 monozygotic (MZ) twin pairs from the Swedish Adoption Twin Study of Aging (SATSA). We used an MZ twin pair difference approach to examine the possibility that genotype was associated with intrapair variability and thus suggestive of genotype–nonshared environment interactions. Multiple ‘variability genes’ were found for longitudinal change in a semantic memory task including candidates coding for apolipoprotein E (APOE) and estrogen receptor alpha (ESR1) as well as serotonin candidates (HTR2Aand5HTT). One candidate also related to variability in change in episodic memory (5HTT). Of the significant associations observed, generally results indicated that MZ pairs who carry putative risk alleles were less variable than noncarriers, suggesting that noncarriers may be more sensitive to environmental contexts. We sought to ‘contextualize’ the possible nonshared environmental influences for found gene–environment (G × E) effects by considering intrapair differences in measured social and stress factors, including social support, life events and depressive symptoms. Results suggested that nonshared environmental influences associated with depressive symptoms may moderate the G × E relationship observed forESR1andAPOEand longitudinal semantic memory change whereby noncarriers of putative risk alleles may be relatively more sensitive to depressionevoking environmental contexts than carriers of the risk allele. Thus, the contexts that facilitate or reduce depressive symptoms may affect semantic memory resiliency dependent on genotype. Further work ought to consider larger sample sizes as well as consider additional social and contextual factors.
Genetic Contribution to the P3 in Young and Middle-Aged Adults
Authors: Smit Dirk J. A. , Posthuma Danielle , Boomsma Dorret I. , de Geus Eco J.C.
Published: April 2007

Previous studies in young and adolescent twins suggested substantial genetic contributions to the amplitude and latency of the P3 evoked by targets in an oddball paradigm. Here we examined whether these findings can be generalized to adult samples. A total of 651 twins and siblings from 292 families participated in a visual oddball task. In half of the subjects the age centered around 26 (young adult cohort), in the other half the age centered around 49 (middle-aged adult cohort). P3 peak amplitude and latency were scored for 3 midline leads Pz, Cz, and Fz. No cohort differences in heritability were found. P3 amplitude (∼50%) and latency (∼45%) were moderately heritable for the 3 leads. A single genetic factor influenced latency at all electrodes, suggesting a single P3 timing mechanism. Specific genetic factors influenced amplitude at each lead, suggesting local modulation of the P3 once triggered. Genetic analysis of the full event-related potential waveform showed that P3 heritability barely changes from about 100 ms before to 100 ms after the peak. Age differences are restricted to differences in means and variances, but the proportion of genetic variance as part of the total variance of midline P3 amplitude and latency does not change from young to middle-aged adulthood.
Personality, Health and Lifestyle in a Questionnaire Family Study: A Comparison Between Highly Cooperative and Less Cooperative Families
Authors: Distel Marijn A. , Ligthart Lannie , Willemsen Gonneke , Nyholt Dale R. , Trull Timothy J. , Boomsma Dorret I.
Published: April 2007

The effect of nonresponse on health and lifestyle measures has received extensive study, showing at most relatively modest effects. Nonresponse bias with respect to personality has been less thoroughly investigated. The present study uses data from responding individuals as a proxy for the missing data of their nonresponding family members to examine the presence of nonresponse bias for personality traits and disorders as well as health and lifestyle traits. We looked at the Big Five personality traits, borderline personality disorder (BPD) features, attention-deficit/hyperactivity disorder, Anger, and several measures of health (Body Mass Index, migraine) and lifestyle (smoking, alcohol use). In general, outcomes tend to be slightly more favorable for individuals from highly cooperative families compared to individuals from less cooperative families. The only significant difference was found for BPD features (p = .001). However, the absolute difference in mean scores is very small, less than 1 point for a scale ranging from 0 to 72. In conclusion, survey data on personality, health and lifestyle are relatively unbiased with respect to nonresponse.
Multiple Maternities and Neighborhood Income
Authors: Urquia Marcelo Luis , Frank John William , Glazier Richard Henry , Moineddin Rahim
Published: April 2007

This study aimed to examine differences in multiple maternities by neighborhood-income levels in Toronto, Canada. Hospital records were used to perform secondary analysis of 144,731 maternities resulting in single or multiple infants live-born to mothers residing in the City of Toronto 1996 to 2001. The independent variable was neighborhood income, defined as mean household neighborhoodincome quintiles. Multiple logistic regression analysis was used to compute adjusted odds ratios (AORs) and 95% confidence intervals (CIs). Differences by income levels were found in twin maternities but not in higher order maternities. Twin maternities were more likely to occur in the richest neighborhood-income quintile compared to the rest of the population (AOR: 1.25, 95% CI: 1.10-1.41), after adjustment for potential confounders. The positive association between high neighborhood income and twin maternities found in this study suggests that the richest neighborhoods select families whose characteristics pose them at increased risk of having twins. Further studies are needed to clarify the underlying mechanisms leading to socioeconomic differences in multiple births.
Determination of residual stress in bonded wood components
Authors: Scheffler Michael , Weber Tony , Niemz Peter , Hardtke Hans-Jürgen
Published: April 2007

Climate tests on double-layered samples were performed to detect deformation and induced stress concentrations. The paper is divided into two parts. The first presents experimental results for double-layered specimens. These specimens consisted of two wooden layers (each conditioned at a different climate before bonding) that were bonded using two different adhesives. The displacement field of the specimens was measured by means of digital fringe projection. The second part presents finite element results for two model stages using coupled thermal-mechanical analysis. For the first simple model, both orthotropic properties and the grain orientations were taken into account to investigate the behavior of the layers in principle. The results were compared to those for the experimental set-up. The improved second-stage model considers the adhesive layer between the wooden layers. The experimental and computational results of the improved simulation model are in good agreement. In the future, if inelastic material behavior is considered in a competitively superior manner, even better simulation results can be expected.
Penetration of poly(ethylene glycol) into wood cell walls of red pine
Authors: Jeremic Dragica , Cooper Paul , Brodersen Peter
Published: April 2007

Penetration of poly(ethylene glycol) (PEG) with a wide range of molecular weights into cell walls of red pine wood was investigated. The study included bulking measurements and visualization of diffusion of brominated PEG by scanning transmission electron microscopy coupled to an energy-dispersive X-ray analyzer (STEM-EDXA) and a time-of-flight secondary ion mass spectrometer (ToF-SIMS). Both bulking and visualization techniques were in agreement, showing that all molecular weights of the polymer (PEG 1000, PEG 8000, and PEG 20000) are capable of penetrating cell walls. ToF-SIMS was more sensitive than STEM-EDXA, allowing visualization of lower amounts of brominated PEG. A trend to higher concentrations of PEG in the middle lamellae was observed.
The Ethical and Regulatory Problems in the Stem Cell Scandal
Authors: Aera Han
Published: April 2007

The recent stem cell scandal of fabrication of two papers published in Science by Dr. Hwang Woo Suk shocked the world and devastated the South Korean society. Investigations conducted by the South Korean government have revealed a variety of ethical and regulatory failures. In this paper, I first explain the South Korean regulatory background to research conducted on human subjects in general and on biotechnological research in particular, and then analyze the ethical and regulatory problems affecting the research for the two papers published in 2004 and 2005 by Dr. Hwang's team, respectively. These problems can be summarized as: 1) problems regarding egg donation (lack of informed consent and donation by vulnerable subjects), 2) ambiguous record-keeping of research funding, 3) insufficient reviews by the two local IRBs (an already established IRB and a newly established IRB, both deferred to the principal scientist's heavy-handed influence), 4) too close ties between the research team and government officials, and 5) the National Bioethics Committee's inertia and lack of impartiality.
Using Demographic Models to Determine Intrinsic Rate of Increase and Sustainable Fishing for Elasmobranchs: Pitfalls, Advances, and Applications
Authors: Gedamke Todd , Hoenig John M. , Musick John A. , DuPaul William D. , Gruber Samuel H.
Published: April 2007

Leslie matrices and life tables are demographic models commonly used to evaluate the ability of specific elasmobranch life history strategies to sustain given levels and patterns of fishing pressure. These models are generally density independent and provide an instantaneous rate of population growth for a specified set of life history traits that correspond to a specific population size. Many investigators are using these models to compute rates of population growth that they claim are estimates of the maximum population growth rate (rintrinsic); they then use these estimates to compute purported estimates of maximum sustainable fishing mortality. However, neither a Leslie matrix nor a life table can be used to estimate rintrinsic without additional information, except in the special case where a severely depleted population is modeled. Only in a severely depleted population will competition for resources be at a minimum and both density-dependent compensation and the rate of population growth be at a maximum (i.e., at rintrinsic). The fundamental problem is to determine the life history parameters that would occur if the population were extremely depleted because extensive observations on extremely depleted populations are rare. In the absence of such data, rintrinsic can only be estimated from these types of density-independent models by extrapolating observed population growth rates toward zero population size. We illustrate the problems in, and describe methods for, estimating rintrinsic and present information on two species of elasmobranch: barndoor skate Dipturus laevis and lemon shark Negaprion brevirostris
Quantification of the Vital Rates, Abundance, and Status of a Critical, Endemic Population of Bonneville Cutthroat Trout
Authors: Budy Phaedra , Thiede Gary P. , McHugh Peter
Published: April 2007

Most subspecies of cutthroat trout Oncorhynchus clarkii are imperiled or extinct due to the combined effects of habitat degradation and interactions with exotic species. To quantify abundance and vital rates and evaluate trends, we selected a large population of Bonneville cutthroat trout O. clarkii utah from the Logan River of northern Utah, a river characterized by high-quality and connected habitat. Over a 5-year period, we completed a comprehensive population assessment, including depletion-based abundance estimates and a mark–recapture study (1,050 tagged fish) of site fidelity, growth, and survival. Population density exceeded 1,500 cutthroat trout/km at high-elevation sites; this is substantially higher than most other reported densities of inland, stream-type cutthroat trout. Fish demonstrated extremely high rates of site fidelity on average (92%; SE = 6%), and growth rates were also high (up to 0.50 g/d; mean = 0.09 g/d). Cormack–Jolly–Seber survival rates (fish ≥ 100 mm) increased with age-class (group effect) and condition (individual covariate) and ranged from over 64% at high-elevation sites to approximately 30% at lower-elevation sites. Population growth rates (λ) appeared to be declining overall; however, 95% confidence intervals of λ frequently overlapped 1.0, indicating high variability that limited conclusions about future status. Both survival rate and fish density were consistently lower at sites where Bonneville cutthroat trout were sympatric with exotic brown trout Salmo trutta. The continuity, connectedness, and large size of this habitat fragment of the Logan River have clearly contributed to the persistence of this population. Our results provide important conservation and recovery benchmarks for identifying rangewide limiting factors of cutthroat trout. We recommend a precautionary approach to management of this endemic and important population; potential options include habitat protection or restoration and the removal of exotic brown trout.
Otolith Trace Element Chemistry as an Indicator of Anadromy in Yukon River Drainage Coregonine Fishes
Authors: Brown Randy J. , Bickford Nate , Severin Ken
Published: April 2007

Eight coregonine species have been documented in the Yukon River drainage. They include inconnuStenodus leucichthys, broad whitefishCoregonus nasus, humpback whitefishC. pidschian, Alaska whitefishC. nelsonii, least ciscoC. sardinella, Bering ciscoC. laurettae, round whitefishProsopium cylindracium, and pygmy whitefishP. coulterii. Personal use, sport, and commercial fisheries within the drainage target several of these species. Some species are capable of anadromous life histories, as evidenced by their presence in estuaries, yet few studies have investigated the upstream migrations of anadromous components of these populations. Only inconnu migrations have been previously examined in the Yukon River drainage. We investigated the distribution of anadromous coregonine fish in the Yukon River drainage in Alaska using sampling and otolith chemistry procedures. Six species were identified in sample collections from eight regions of the drainage between 1,200 and 2,000 km upstream from the Bering Sea. Gonadosomatic indices indicated that most sampled fish of all species were mature and preparing to spawn. Anadromous inconnu, broad whitefish, and humpback whitefish were distributed in the Yukon River and its tributaries to a maximum distance of 1,700 km from the sea. Anadromous least cisco were distributed in the Yukon River and its tributaries up to 1,600 km from the sea, whereas anadromous Bering cisco were present in the Yukon River main stem as far upstream as 2,000 km. No anadromous round whitefish were detected. Few coregonine spawning areas have been identified, so the actual migration distances of anadromous species may be greater than presented here.
A Structured Approach for Developing Indices of Biotic Integrity: Three Examples from Streams and Rivers in the Western USA
Authors: Whittier Thomas R. , Hughes Robert M. , Stoddard John L. , Lomnicky Gregg A. , Peck David V. , Herlihy Alan T.
Published: April 2007

In the late 1990s the Environmental Monitoring and Assessment Program of the U.S. Environmental Protection Agency developed a structured set of tests to evaluate and facilitate selection of metrics for indices of biotic integrity (IBIs). These IBIs were designed to be applicable across multistate regions as part of a national assessment of all U.S. waters. Here, we present additional steps in, and refinements to, that IBI development process. We used fish and amphibian assemblage data from 932 stream and river sites in 12 western U.S. states to develop IBIs for Mountains, Xeric, and Plains ecoregions. We divided 237 candidate metrics into nine metric classes representing different attributes of assemblage structure and function. For each ecoregion we sequentially eliminated metrics by testing metric range, signal‐to‐noise ratios, responsiveness to disturbance, and redundancy to select the best metric in each class. The IBIs for the Mountains and Plains each had seven metrics and the Xeric IBI had five. In the Mountains, half of the estimated stream length that could be assessed had IBI scores greater than 62 (out of 100). In the Xeric and Plains, half the stream length had scores no greater than 50 and no greater than 37, respectively. An estimated 16% of Xeric stream length had scores greater than 62 (the median for the Mountains), while 5% of Plains stream length had scores that exceeded 62. This IBI development process is less subjective and more streamlined and has more clearly defined criteria for metric selection and scoring than those used in the past, while maintaining a strong ecological foundation.
Development and Reliability Testing of the Clinical Pharmacist Recommendation Taxonomy
Authors: Hoth Angela B. , Carter Barry L. , Ness Jose , Bhattacharyya Anjan , Shorr Ronald I. , Rosenthal Gary E. , Kaboli Peter J.
Published: April 2007

Study Objective. To evaluate the reliability of a newly developed taxonomy—the Clinical Pharmacist Recommendation (CPR) taxonomy—to classify clinical pharmacy interventions.

Design. The CPR taxonomy was developed and refined in three phases. In each phase, reviewers independently reviewed recommendations made by a clinical pharmacist‐physician team and categorized them into mutually exclusive categories: priority, problem, and response. Interrater reliability was assessed for all categories during each development phase.

Setting. Primary care clinics of a Veterans Affairs Medical Center.

Patients. Fifty‐three patients enrolled in the Veterans Affairs Enhanced Pharmacy Outpatient Clinic (EPOC) trial.

Measurements and Main Results. Interrater reliability was assessed using the κ statistic. A total of 423 recommendations were evaluated during the three testing phases. In the final testing phase, agreement was moderate for pharmacotherapy problem subcategories (κ=0.57), substantial for pharmacotherapy problem primary categories (κ=0.64), and almost perfect for response categories (κ=0.85). Taxonomy completion time/patient averaged 4.6 minutes (range 1–11 min).

Conclusion. The CPR taxonomy provides a reliable method to systematically evaluate clinical pharmacy recommendations based on the therapeutic problem identified and specific action recommended to resolve the problem.
Prevalence of Illicit Use and Abuse of Prescription Stimulants, Alcohol, and Other Drugs Among College Students: Relationship with Age at Initiation of Prescription Stimulants
Authors: Kaloyanides Kristy B. , McCabe Sean E. , Cranford James A. , Teter Christian J.
Published: April 2007

Study Objective. To examine associations between age at initiation of prescription stimulants and illicit use and abuse of prescription stimulants, alcohol, and other drugs among college students in the United States.

Design. Web‐based survey of college students.

Setting. A large (full‐time undergraduate population > 20,000) university.

Intervention. A Web‐based survey was sent to a random sample of 5389 undergraduate college students plus an additional 1530 undergraduate college students of various ethnic backgrounds over a 2‐month period.

Measurements and Main Results. Alcohol abuse was assessed by including a modified version of the Cut Down, Annoyance, Guilt, Eye‐opener (CAGE) instrument. Drug use‐related problems were assessed with a slightly modified version of the Drug Abuse Screening Test, short form (DAST‐10). The final sample consisted of 4580 undergraduate students (66% response rate). For the analyses, five subgroups were created based on age at initiation of prescription stimulant use: no prescription stimulant use, grades kindergarten (K)–4, grades 5–8, grades 9–12, and college. Undergraduate students to whom stimulants were prescribed in grades K‐4 reported similar rates of alcohol and other drug use compared with that of the group that had no prescription stimulant use. For example, students who started prescription stimulants in grades K‐4 were no more likely to report coingestion of alcohol and illicit prescription stimulants (odds ratio [OR] 1.4, 95% confidence interval [CI] 0.2–11.5, NS] than the group that had no prescription stimulant use. However, undergraduate students whose prescription stimulant use began in college had significantly higher rates of alcohol and other drug use. For example, students who started a prescription stimulant in college were almost 4 times as likely (OR 3.7, 95% CI 1.9‐7.1, p<0.001) to report at least three positive indicators of drug abuse on the DAST‐10 compared with the group that had no prescription stimulant use.

Conclusions. In concordance with results of previous research, these results indicate that initiation of prescription stimulants during childhood is not associated with increased future use of alcohol and other drugs.
Recombinant Activated Factor VII Treatment of Retroperitoneal Hematoma in a Patient with Renal Failure Receiving Enoxaparin and Clopidogrel
Authors: Cherfan Antoine , Arabi Yaseen , Askar Ahmed Al , Shimemeri Abdullah Al
Published: April 2007

Enoxaparin is a low‐molecular‐weight heparin that has pharmacokinetic and therapeutic advantages over unfractionated heparin in certain clinical conditions. However, its administration is not without risk. We describe the case of a 70‐year‐old woman with numerous medical problems who developed severe retroperitoneal bleeding after receiving several therapeutic doses of subcutaneous enoxaparin that inadvertently were not adjusted for her renal function until day 14 of therapy. She had severe bleeding with hemodynamic instability and required massive transfusions of blood products. Her bleeding could be controlled only by administration of four doses of recombinant activated factor VII (factor VIIa) in addition to embolization of the bleeding sites through angiographic microcoiling. The patient's hemodynamic status improved, and her hemoglobin level stabilized. This case report provides evidence of the clinical effectiveness of factor VIIa use as part of the management of refractory enoxaparin‐induced retroperitoneal bleeding. However, further studies are needed to validate the dose‐response relationship and further support the clinical utility of factor VIIa in this life‐threatening situation.
Severe Lactic Acidosis Associated with Linezolid Use in a Patient with the Mitochondrial DNA A2706G Polymorphism
Authors: Carson John , Cerda Jorge , Chae Jong‐Hee , Hirano Michio , Maggiore Peter
Published: April 2007

Linezolid, an oxazolidinone antimicrobial, exerts its effect by binding to bacterial 23S ribosomal RNA, preventing the formation of the initiation complex. Its use is associated with reversible hyperlactatemia and lactic acidosis, and inhibition of mitochondrial protein synthesis may be the mechanism underlying this adverse effect. We describe a 35‐year‐old woman who developed severe lactic acidosis after she received linezolid for 35 days to treat a disseminated infection with Mycobacterium avium‐intracellulare complex. This patient was found to have the mitochondrial DNA polymorphism A2706G, a variation previously suggested to predispose individuals to linezolid‐associated lactic acidosis. In the future, increased understanding of the mitochondrial genome and its associated polymorphisms may allow us to identify patients at risk for adverse effects that were previously classified as idiosyncratic.
Thermal synthesis and characterization of AlχLa1-χ
P3O9
Authors: Bělina Petr , Šulcová Petra , Trojan Miroslav , Mazurek Pavel
Published: April 2007

New binary lanthanum-aluminum triphosphates were synthesized by thermal-condensation method from H3PO4, La2O3 and Al(OH)3. These pigments could be potentially used as special inorganic pigments; their corrosion-inhibition properties were widely studied. Synthesis conditions were determined on the basis of DTA and TG measurements. The products were also characterized by X-ray diffraction analysis. Physical properties — density by pycnometric method, particle size distribution, oil number and critical pigment volume concentration (CPVC), pH and specific conductivity of their aqueous extracts were also determined.
Minimotif Miner: A Computational Tool to Investigate Protein Function, Disease, and Genetic Diversity
Authors: Schiller Martin R.
Published: April 2007

The Minimotif Miner Web site contains information on several hundred short functional motifs in a single database, and allows the user to search protein queries for the presence of these motifs. Scoring based on evolutionary conservation, protein surface prediction, and motif frequency can be used in conjunction with other motif programs and the known biology of the query to reduce false‐positive predictions and select short motifs for experimental pursuit.
Assays for Determination of Protein Concentration
Authors: Olson Bradley J.S.C. , Markwell John
Published: April 2007

Biochemical analysis of proteins relies on accurate quantitation of protein concentration. This unit describes how to perform commonly used protein assays, e.g., Lowry, Bradford, BCA, and UV spectroscopic protein assays. The primary focus of the unit is assay selection, emphasizing sample and buffer compatibility. Protein assay standard curves and data processing fundamentals are discussed in detail. This unit also details high‐throughput adaptations of the commonly used protein assays, and also contains a protocol for BCA assay of total protein in SDS‐PAGE sample buffer that is used for equal loading of SDS‐PAGE gels, which is reliable, inexpensive, and quick.
Recombineering: Genetic Engineering in Bacteria Using Homologous Recombination
Authors: Thomason Lynn , Court Donald L. , Bubunenko Mikail , Costantino Nina , Wilson Helen , Datta Simanti , Oppenheim Amos
Published: April 2007

The bacterial chromosome and plasmids can be engineered in vivo by homologous recombination using PCR products and synthetic oligonucleotides as substrates. This is possible because bacteriophage‐encoded recombination functions efficiently to recombine sequences with homologies as short as 35 to 40 bases. This recombineering allows DNA sequences to be inserted or deleted without regard to location of restriction sites. This unit first describes preparation of electrocompetent cells expressing the recombineering functions and their transformation with dsDNA or ssDNA. Support protocols describe a two‐step method of making genetic alterations without leaving any unwanted changes, and a method for retrieving a genetic marker (cloning) from the E. coli chromosome or a co‐electroporated DNA fragment and moving it onto a plasmid. A method is also given to screen for unselected mutations. Additional protocols describe removal of defective prophage, methods for recombineering.
Constructing Recombinant DNA Molecules by PCR
Authors: Elion Elaine A. , Marina Pablo , Yu Lu
Published: April 2007

This unit describes the use of PCR to construct hybrid DNA molecules. The unit provides an overview of how PCR can be exploited to accomplish numerous cloning strategies. The Basic Protocol outlines the PCR amplification and cloning strategies. The Commentary includes a troubleshooting guide for problems most frequently encountered in PCR cloning, plus four specific examples of the application of this technique to create in‐frame fusion proteins, to create recombinant DNA products, to generate deletions and inversions by inverse PCR, and to introduce mutagenized PCR products or specific mutations or fusions by gap repair in yeast.
Strategies for Large‐Insert Cloning and Analysis
Authors: Smith Douglas R. , Moir Donald T.
Published: April 2007

This revised introduction provides an up‐to‐date overview of available resources and methods for identifying, mapping, manipulating, and analyzing large‐insert (BAC, YAC, PAC, and P1) clones from the human genome or from other genomes. The table listing available libraries and clone resources has been updated, emphasizing widely used resources that are readily available and that were also used to map and sequence the human genome. Mapping references have been updated, along with links to web sites that provide online access to integrated mapping and sequencing resources. Additional information is included on restriction endonuclease fingerprinting approaches and on transformation‐associated recombination (TAR) cloning methods for rescue of genes or genomic segments from specific cell types or individuals.
Characterization of Flow Cytometer Instrument Sensitivity
Authors: Hoffman Robert A. , Wood James C.S.
Published: April 2007

Fluorescence sensitivity, measured in terms of resolution, allows the researcher to more accurately answer the question of how dim a cell can be and still be resolvable from another population. This measure focuses on the width, i.e., the standard deviation, of the population distributions and not on the location, i.e., the mean intensity, of populations on a histogram scale relative to the background. To determine the fluorescence sensitivity in terms of the resolution, both the detection efficiency, Q, and optical background, B, need to be measured. Both factors affect the ability to resolve dimly fluorescent subpopulations, and both factors are required to uniquely characterize the performance of a flow cytometer. Using Q and B, it is possible to determine the minimum fluorescence intensity that is resolvable from the background or from another population. This unit describes a practical and robust approach to measure the critical factors that determine the ability of a flow cytometer to analyze dimly fluorescent particles.
Separation Index: An Easy‐to‐Use Metric for Evaluation of Different Configurations on the Same Flow Cytometer
Authors: Bigos Martin
Published: April 2007

A quick and understandable method, using material readily available in a biology laboratory, for evaluating the measurement sensitivity of flow cytometers is presented in detail. Two examples of its use, in determining an optimal emission filter and in evaluating compensation, are also presented.
Separation of binary mixtures of carbon dioxide and methane through sulfonated polycarbonate membranes
Authors: Sridhar S. , Aminabhavi Tejraj M. , Ramakrishna M.
Published: April 2007

Polycarbonate (PC) was sulfonated to varying degrees using acetyl sulfate. FTIR and NMR experiments were carried out to confirm sulfonation. The membranes were characterized by DSC and TGA to assess thermal stability. Ion exchange capacity (IEC) and degree of sulfonation (DS) were determined and their effect on permeation of CO2 and CH4 gases was investigated. Free volume fractions (FVF) of the membranes were found to decrease from 0.31 to 0.19 as the DS increased from 0 to 39.4%. Single gas permeation studies revealed that sulfonated PC exhibited higher selectivities than unmodified PC at reduced permeability. For a DS of 14.4%, sulfonated PC exhibited a selectivity of 36.1, which was 1.7 times that of unmodified PC, whereas the permeability dropped from 8.4 to 4.7 Barrers. In case of binary CO2/CH4 mixture permeation through PC membrane of the same DS, an increase in CO2 feed concentration from 5 to 40 mol % produced an increase in permeability from 0.24 to 2.0 Barrers and a rise in selectivity from 11.7 to 27.2 at constant feed pressure (20 bar) and temperature (30°C). A rise in the feed pressure from 5 to 30 bar at a constant feed composition of 5% CO2 resulted in a reduction in permeability from 0.38 to 0.2 Barrers and selectivity from 15.6 to 10.2. Sulfonated PC was found to be a promising candidate for separation of CO2 from CH4. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Rheological characterization of chitosan matrices: Influence of biopolymer concentration
Authors: Diez‐Sales O. , Dolz M. , Hernández M. J. , Casanovas A. , Herraez M.
Published: April 2007

Viscoelastic properties of chitosan (CH), chitosan‐poly(ethylene glycol) 400 (CH‐PEG), and chitosan‐poly(ethylene glycol) 400 with glyoxal as crosslinking agent (CH‐PEG‐Gly) systems were studied to analyze the effect of chitosan concentration (from 0.83 to 1.67%). Dynamic moduli increase as chitosan concentration increases for all systems. For CH and CH‐PEG systems the loss modulus (G″) is greater than the storage modulus (G′) with predominance of the viscous over the elastic behavior. This corresponds to the characteristic behavior of solutions (nonstructured systems). The presence of PEG 400 induces a complementary reinforcement of the mechanical properties of the system. Except for the lowest chitosan concentration, when glyoxal was added to the CH‐PEG systems, a gelled matrix was obtained. In this case, G′ is greater than G″, and practically independent of frequency. This behavior is typical of three‐dimensional networks and indicates true gel formation, showing clear elastic behavior (tan δ < 1). In creep and recovery analysis, CH‐PEG‐Gly systems exhibited distinct regions that were mathematically modeled using Burger's model. This analysis shows that the CH‐PEG‐Gly matrices (from 1.25 to 1.67%) recover almost totally (100%). Therefore, these matrices could be useful as systems for the development of films for topical hydrophilic drug delivery, and the levels of the residual viscosity (η0) or the complex viscosity (η*) could be used to control drug release. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Effect of strain on the properties of a styrene–butadiene rubber filled with multiwall carbon nanotubes
Authors: Bokobza Liliane , Belin Colette
Published: April 2007

Multiwall carbon nanotubes were dispersed in a styrene–butadiene copolymer. The effect of nanotube concentration on the tensile characteristics of the composites was examined. Electrical properties carried out under uniaxial extension show an increase in resistivity upon gradual stretching. A second stretch performed after total release of the stress was shown to lead to a flat response in resistivity. Atomic force microscopy was used to examine orientational effects and changes in filler structure occurring upon application of an uniaxial deformation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007