bluuebunny/crossref_metadata_2025 huggingface dataset:
Systems biology approach reveals that overflow metabolism of acetate in Escherichia coli is triggered by carbon catabolite repression of acetyl-CoA synthetase
Authors: Valgepea Kaspar , Adamberg Kaarel , Nahku Ranno , Lahtvee Petri-Jaan , Arike Liisa , Vilu Raivo
Published: December 2010

Background

The biotechnology industry has extensively exploited Escherichia coli for producing recombinant proteins, biofuels etc. However, high growth rate aerobic E. coli cultivations are accompanied by acetate excretion i.e. overflow metabolism which is harmful as it inhibits growth, diverts valuable carbon from biomass formation and is detrimental for target product synthesis. Although overflow metabolism has been studied for decades, its regulation mechanisms still remain unclear.

Results

In the current work, growth rate dependent acetate overflow metabolism of E. coli was continuously monitored using advanced continuous cultivation methods (A-stat and D-stat). The first step in acetate overflow switch (at μ = 0.27 ± 0.02 h-1) is the repression of acetyl-CoA synthethase (Acs) activity triggered by carbon catabolite repression resulting in decreased assimilation of acetate produced by phosphotransacetylase (Pta), and disruption of the PTA-ACS node. This was indicated by acetate synthesis pathways PTA-ACKA and POXB component expression down-regulation before the overflow switch at μ = 0.27 ± 0.02 h-1 with concurrent 5-fold stronger repression of acetate-consuming Acs. This in turn suggests insufficient Acs activity for consuming all the acetate produced by Pta, leading to disruption of the acetate cycling process in PTA-ACS node where constant acetyl phosphate or acetate regeneration is essential for E. coli chemotaxis, proteolysis, pathogenesis etc. regulation. In addition, two-substrate A-stat and D-stat experiments showed that acetate consumption capability of E. coli decreased drastically, just as Acs expression, before the start of overflow metabolism. The second step in overflow switch is the sharp decline in cAMP production at μ = 0.45 h-1 leading to total Acs inhibition and fast accumulation of acetate.

Conclusion

This study is an example of how a systems biology approach allowed to propose a new regulation mechanism for overflow metabolism in E. coli shown by proteomic, transcriptomic and metabolomic levels coupled to two-phase acetate accumulation: acetate overflow metabolism in E. coli is triggered by Acs down-regulation resulting in decreased assimilation of acetic acid produced by Pta, and disruption of the PTA-ACS node.
Facilitating Learning in Large Lecture Classes: Testing the “Teaching Team” Approach to Peer Learning
Authors: Stanger-Hall Kathrin F. , Lang Sarah , Maas Martha
Published: December 2010

We tested the effect of voluntary peer-facilitated study groups on student learning in large introductory biology lecture classes. The peer facilitators (preceptors) were trained as part of a Teaching Team (faculty, graduate assistants, and preceptors) by faculty and Learning Center staff. Each preceptor offered one weekly study group to all students in the class. All individual study groups were similar in that they applied active-learning strategies to the class material, but they differed in the actual topics or questions discussed, which were chosen by the individual study groups. Study group participation was correlated with reduced failing grades and course dropout rates in both semesters, and participants scored better on the final exam and earned higher course grades than nonparticipants. In the spring semester the higher scores were clearly due to a significant study group effect beyond ability (grade point average). In contrast, the fall study groups had a small but nonsignificant effect after accounting for student ability. We discuss the differences between the two semesters and offer suggestions on how to implement teaching teams to optimize learning outcomes, including student feedback on study groups.
Just the Facts? Introductory Undergraduate Biology Courses Focus on Low-Level Cognitive Skills
Authors: Momsen Jennifer L. , Long Tammy M. , Wyse Sara A. , Ebert-May Diane
Published: December 2010

Introductory biology courses are widely criticized for overemphasizing details and rote memorization of facts. Data to support such claims, however, are surprisingly scarce. We sought to determine whether this claim was evidence-based. To do so we quantified the cognitive level of learning targeted by faculty in introductory-level biology courses. We used Bloom's Taxonomy of Educational Objectives to assign cognitive learning levels to course goals as articulated on syllabi and individual items on high-stakes assessments (i.e., exams and quizzes). Our investigation revealed the following: 1) assessment items overwhelmingly targeted lower cognitive levels, 2) the cognitive level of articulated course goals was not predictive of the cognitive level of assessment items, and 3) there was no influence of course size or institution type on the cognitive levels of assessments. These results support the claim that introductory biology courses emphasize facts more than higher-order thinking.
Learner-Centered Inquiry in Undergraduate Biology: Positive Relationships with Long-Term Student Achievement
Authors: Derting Terry L. , Ebert-May Diane
Published: December 2010

We determined short- and long-term correlates of a revised introductory biology curriculum on understanding of biology as a process of inquiry and learning of content. In the original curriculum students completed two traditional lecture-based introductory courses. In the revised curriculum students completed two new learner-centered, inquiry-based courses. The new courses differed significantly from those of the original curriculum through emphases on critical thinking, collaborative work, and/or inquiry-based activities. Assessments were administered to compare student understanding of the process of biological science and content knowledge in the two curricula. More seniors who completed the revised curriculum had high-level profiles on the Views About Science Survey for Biology compared with seniors who completed the original curriculum. Also as seniors, students who completed the revised curriculum scored higher on the standardized Biology Field Test. Our results showed that an intense inquiry-based learner-centered learning experience early in the biology curriculum was associated with long-term improvements in learning. We propose that students learned to learn science in the new courses which, in turn, influenced their learning in subsequent courses. Studies that determine causal effects of learner-centered inquiry-based approaches, rather than correlative relationships, are needed to test our proposed explanation.
Using Invention to Change How Students Tackle Problems
Authors: Taylor Jared L. , Smith Karen M. , van Stolk Adrian P. , Spiegelman George B.
Published: December 2010

Invention activities challenge students to tackle problems that superficially appear unrelated to the course material but illustrate underlying fundamental concepts that are fundamental to material that will be presented. During our invention activities in a first-year biology class, students were presented with problems that are parallel to those that living cells must solve, in weekly sessions over a 13-wk term. We compared students who participated in the invention activities sessions with students who participated in sessions of structured problem solving and with students who did not participate in either activity. When faced with developing a solution to a challenging and unfamiliar biology problem, invention activity students were much quicker to engage with the problem and routinely provided multiple reasonable hypotheses. In contrast the other students were significantly slower in beginning to work on the problem and routinely produced relatively few ideas. We suggest that the invention activities develop a highly valuable skill that operates at the initial stages of problem solving.
How Accurate Is Peer Grading?
Authors: Freeman Scott , Parks John W.
Published: December 2010

Previously we showed that weekly, written, timed, and peer-graded practice exams help increase student performance on written exams and decrease failure rates in an introductory biology course. Here we analyze the accuracy of peer grading, based on a comparison of student scores to those assigned by a professional grader. When students graded practice exams by themselves, they were significantly easier graders than a professional; overall, students awarded ≈25% more points than the professional did. This difference represented ≈1.33 points on a 10-point exercise, or 0.27 points on each of the five 2-point questions posed. When students graded practice exams as a group of four, the same student-expert difference occurred. The student-professional gap was wider for questions that demanded higher-order versus lower-order cognitive skills. Thus, students not only have a harder time answering questions on the upper levels of Bloom's taxonomy, they have a harder time grading them. Our results suggest that peer grading may be accurate enough for low-risk assessments in introductory biology. Peer grading can help relieve the burden on instructional staff posed by grading written answers—making it possible to add practice opportunities that increase student performance on actual exams.
Learn before Lecture: A Strategy That Improves Learning Outcomes in a Large Introductory Biology Class
Authors: Moravec Marin , Williams Adrienne , Aguilar-Roca Nancy , O'Dowd Diane K.
Published: December 2010

Actively engaging students in lecture has been shown to increase learning gains. To create time for active learning without displacing content we used two strategies for introducing material before class in a large introductory biology course. Four to five slides from 2007/8 were removed from each of three lectures in 2009 and the information introduced in preclass worksheets or narrated PowerPoint videos. In class, time created by shifting lecture material to learn before lecture (LBL) assignments was used to engage students in application of their new knowledge. Learning was evaluated by comparing student performance in 2009 versus 2007/8 on LBL-related question pairs, matched by level and format. The percentage of students who correctly answered five of six LBL-related exam questions was significantly higher (p < 0.001) in 2009 versus 2007/8. The mean increase in performance was 21% across the six LBL-related questions compared with <3% on all non-LBL exam questions. The worksheet and video LBL formats were equally effective based on a cross-over experimental design. These results demonstrate that LBLs combined with interactive exercises can be implemented incrementally and result in significant increases in learning gains in large introductory biology classes.
Editorial: 25-Hydroxycholesterol: a new life in immunology
Authors: McDonald Jeffrey G , Russell David W
Published: December 2010

A discussion on paper by Park and Scott revealing the signaling pathways leading to the synthesis of a potent immunoregulatory oxysterol by macrophage and dendritic cells.
Editorial: Tregs and BCG—dangerous liaisons in TB
Authors: Coleman Michelle M , Keane Joseph , Mills Kingston H G
Published: December 2010

A discussion on paper by Ho et al. providing evidence to support the hypothesis that Treg cells induced by environmental mycobacteria do indeed constrain immunity induced by BCG.
Inequality: an underacknowledged source of mental illness and distress
Authors: Pickett Kate E. , Wilkinson Richard G.
Published: December 2010

Greater income inequality is associated with higher prevalence of mental illness and drug misuse in rich societies. There are threefold differences in the proportion of the population suffering from mental illness between more and less equal countries. This relationship is most likely mediated by the impact of inequality on the quality of social relationships and the scale of status differentiation in different societies.
Treatment adherence therapy in people with psychotic disorders: randomised controlled trial
Authors: Staring A. B. P. , Van der Gaag M. , Koopmans G. T. , Selten J. P. , Van Beveren J. M. , Hengeveld M. W. , Loonen A. J. M. , Mulder C. L.
Published: December 2010

Background

Interventions to improve adherence to treatment in people with psychotic disorders have produced inconclusive results. We developed a new treatment, treatment adherence therapy (TAT), whose intervention modules are tailored to the reasons for an individual's non-adherence.

Aims

To examine the effectiveness of TAT with regard to service engagement and medication adherence in out-patients with psychotic disorders who engage poorly.

Method

Randomised controlled study of TAT v. treatment as usual (TAU) in 109 out-patients. Most outcome measurements were performed by masked assessors. We used intention-to-treat multivariate analyses (Dutch Trial Registry: NTR1159).

Results

Treatment adherence therapy v. TAU significantly benefited service engagement (Cohen's d = 0.48) and medication adherence (Cohen's d = 0.43). Results remained significant at 6-month follow-up for medication adherence. Near-significant effects were also found regarding involuntary readmissions (1.9% v. 11.8%, P = 0.053). Symptoms and quality of life did not improve.

Conclusions

Treatment adherence therapy helps improve engagement and adherence, and may prevent involuntary admission.
Parental help-seeking in primary care for child and adolescent mental health concerns: qualitative study
Authors: Sayal Kapil , Tischler Victoria , Coope Caroline , Robotham Sarah , Ashworth Mark , Day Crispin , Tylee Andre , Simonoff Emily
Published: December 2010

Background

Child and adolescent mental health problems are common in primary care. However, few parents of children with mental health problems express concerns about these problems during consultations.

Aims

To explore the factors influencing parental help-seeking for children with emotional or behavioural difficulties.

Method

Focus group discussions with 34 parents from non-specialist community settings who had concerns about their child's mental health. All groups were followed by validation groups or semi-structured interviews.

Results

Most children had clinically significant mental health symptoms or associated impairment in function. Appointment systems were a key barrier, as many parents felt that short appointments did not allow sufficient time to address their child's difficulties. Continuity of care and trusting relationships with general practitioners (GPs) who validated their concerns were perceived to facilitate help-seeking. Parents valued GPs who showed an interest in their child and family situation. Barriers to seeking help included embarrassment, stigma of mental health problems, and concerns about being labelled or receiving a diagnosis. Some parents were concerned about being judged a poor parent and their child being removed from the family should they seek help.

Conclusions

Primary healthcare is a key resource for children and young people with emotional and behavioural difficulties and their families. Primary care services should be able to provide ready access to health professionals with an interest in children and families and appointments of sufficient length so that parents feel able to discuss their mental health concerns.
Stigmatised attitudes in independent pharmacies associated with discrimination towards individuals with opioid dependence
Authors: Luty Jason , Kumar Pramod , Stagias Konstantinos
Published: December 2010

Aims and method

Dispensing of methadone to individuals with opioid dependence is a discretionary service and many independent pharmacies remain unwilling to do this. We aimed to determine whether there was any correlation between negative stigmatised attitude towards these individuals and the likelihood of methadone dispensing. The 20-point Attitude to Mental Illness Questionnaire (AMIQ) was used to assess stigmatised attitudes in a cluster randomised sample of managers of community pharmacies in England.

Results

The response rate was 66%. The AMIQ stigma scores had a median difference of 1 and effect size of 0.42 in favour of those pharmacies which dispensed methadone (mean = 0.53; n = 138) compared with those who did not (mean = 0.93; n = 69; P <0.001).

Clinical implications

The results show a clear behavioural distinction (discrimination) based on stigmatised attitudes towards individuals with opioid dependence. This may arise because managers with stigmatised attitudes refuse to dispense methadone to this group. Conversely, familiarity with these individuals may have a de-stigmatising effect.
The fission yeast rDNA-binding protein Reb1 regulates G1 phase under nutritional stress
Authors: Rodríguez-Sánchez Leonor , Rodríguez-López María , García Zaira , Tenorio-Gómez María , Schvartzman Jorge B. , Krimer Dora B. , Hernández Pablo
Published: December 2010

Yeast Reb1 and its mammalian ortholog TTF1 are conserved Myb-type DNA-binding proteins that bind to specific sites near the 3′-end of rRNA genes (rDNA). Here, they participate in the termination of transcription driven by RNA polymerase I and block DNA replication forks approaching in the opposite direction. We found that Schizosaccharomyces pombe Reb1 also upregulates transcription of the ste9+ gene that is required for nitrogen-starvation-induced growth arrest with a G1 DNA content and sexual differentiation. Ste9 activates the anaphase-promoting complex or cyclosome (‘APC/C’) in G1, targeting B-cyclin for proteasomal degradation in response to nutritional stress. Reb1 binds in vivo and in vitro to a specific DNA sequence at the promoter of ste9+, similar to the sequence recognized in the rDNA, and this binding is required for ste9+ transcriptional activation and G1 arrest. This suggests that Reb1 acts as a link between rDNA metabolism and cell cycle control in response to nutritional stress. In agreement with this new role for Reb1 in the regulation of the G1–S transition, reb1Δ and wee1ts mutations are synthetically lethal owing to the inability of these cells to lengthen G1 before entering S phase. Similarly, reb1Δ cdc10ts cells are unable to arrest in G1 and die at the semi-permissive temperature.
A novel Chk1/2–Lats2–14-3-3 signaling pathway regulates P-body formation in response to UV damage
Authors: Okada Nobuhiro , Yabuta Norikazu , Suzuki Hirokazu , Aylon Yael , Oren Moshe , Nojima Hiroshi
Published: December 2010

Proper response to DNA damage is essential for maintaining the integrity of the genome. Here we show that in response to ultraviolet (UV) radiation, the Lats2 tumor suppressor protein is phosphorylated predominantly by Chk1 and weakly by Chk2 at S408 in vivo, and that this process occurs at all stages of the cell cycle and leads to phosphorylation of 14-3-3γ on S59 by Lats2. Interaction of Lats2 and 14-3-3γ in vivo was confirmed by immunoprecipitation and western blot analysis. Phosphorylated 14-3-3γ translocates to the P-body, where mRNA degradation, translational repression and mRNA surveillance take place. Depletion of Lats2 or 14-3-3γ by siRNA inhibits P-body formation in response to UV, newly implicating Lats2 and 14-3-3 as regulators of P-body formation. By contrast, siRNA-mediated depletion of Lats1, a mammalian paralog of Lats2, showed no such effect. On the basis of these findings, we propose that the Chk1/2–Lats2–14-3-3 axis identified here plays an important role in connecting DNA damage signals to P-body assembly.
Stimulus-induced uncoupling of extracellular signal-regulated kinase phosphorylation from nuclear localization is dependent on docking domain interactions
Authors: Caunt Christopher J. , McArdle Craig A.
Published: December 2010

Many stimuli activate the extracellular signal-regulated kinase (ERK) by phosphorylation on the TEY motif. Activated ERK characteristically accumulates in the nucleus, but the underlying mechanisms involved are unclear. Using automated microscopy to explore ERK regulation in single intact cells, we find that, when protein kinase C or epidermal growth factor receptors are activated, a substantial fraction of the ERK nuclear localization response is uncoupled from TEY phosphorylation. This phosphorylation-unattributable nuclear localization response occurs in the presence of inhibitors of tyrosine phosphatases and protein synthesis. It was also evident with a catalytically inactive ERK2–GFP mutant, and with a mutant incapable of binding the DEF (docking site for ERK, F/Y-X-F/Y-P) domains found in many ERK binding partners. It was, however, reduced by MEK inhibition and by mutations preventing either TEY phosphorylation or D (docking)-domain-dependent ERK binding (D319N). Thus, we show that MEK-catalysed ERK phosphorylation is necessary but not sufficient for the full nuclear localization response: there is an additional phosphorylation-unattributable component of the response that does not reflect induced expression of nuclear anchors and is independent of ERK catalytic activity or DEF-domain binding. It is, however, dependent upon D-domain binding, highlighting distinct roles of ERK motifs during nuclear targeting.
Studying Choice and Change: The Intersection of Institutional Theory and Entrepreneurship Research
Authors: Tolbert Pamela S. , David Robert J. , Sine Wesley D.
Published: December 2010

Although there are many potential points of intersection between institutional theory and contemporary studies of entrepreneurship, these have generally remained distinct literatures, with the connections left more implicit than explicit. We argue that there are a number of benefits to explicitly articulating the links between these bodies of scholarship. In this context, we review work that relates to two key questions we believe are especially likely to benefit from the integration of these literatures—namely, how do institutions affect entrepreneurial choices? And how is entrepreneurship related to changes in institutions? We conclude by considering a number of topics for future research suggested by this integration.
Experimental osteoarthritis induced by surgical realignment of the patella in BALB/c mice
Authors: Chia W.-T. , Pan R.-Y. , Tseng F.-J. , Chen Y.-W. , Feng C.-K. , Lee H.-S. , Chang D.-M. , Sytwu H.-K.
Published: December 2010

The patellofemoral joint is an important source of symptoms in osteoarthritis of the knee. We have used a newly designed surgical model of patellar strengthening to induce osteoarthritis in BALB/c mice and to establish markers by investigating the relationship between osteoarthritis and synovial levels of matrix metalloproteinases (MMPs). Osteoarthritis was induced by using this microsurgical technique under direct vision without involving the cavity of the knee. Degeneration of cartilage was assessed by the Mankin score and synovial tissue was used to determine the mRNA expression levels of MMPs. Irrigation fluid from the knee was used to measure the concentrations of MMP-3 and MMP-9. Analysis of cartilage degeneration was correlated with the levels of expression of MMP.

After operation the patellofemoral joint showed evidence of mild osteoarthritis at eight weeks and further degenerative changes by 12 weeks. The level of synovial MMP-9 mRNA correlated with the Mankin score at eight weeks, but not at 12 weeks. The levels of MMP-2, MMP-3 and MMP-14 mRNA correlated with the Mankin score at 12 weeks. An increase in MMP-3 was observed from four weeks up to 16 weeks. MMP-9 was notably increased at eight weeks, but the concentration at 16 weeks had decreased to the level observed at four weeks.

Our observations suggest that MMP-2, MMP-3 and MMP-14 could be used as markers of the progression of osteoarthritic change.
Use of metal proximal radial endoprostheses for treatment of non-traumatic disorders
Authors: Gokaraju K. , Miles J. , Parratt M. T. R. , Blunn G. W. , Pollock R. C. , Skinner J. A. , Cannon S. R. , Briggs T. W. R.
Published: December 2010

We have reviewed five adult patients treated with endoprosthetic reconstruction of the proximal radius following resection of non-traumatic lesions. The patients had a mean age of 33.4 years (20 to 60) at the time of surgery and the mean follow-up was 7.6 years (0.8 to 16).

Following surgery, all elbows were clinically stable and there was 100% survivorship of the prosthesis. Evaluation of function was assessed clinically and by the Mayo Elbow Performance Score, achieving a mean of 86% (70 to 100).

Results at medium-term follow-up are encouraging with regards to elbow stability, implant survivorship and functional outcome.
Cementless total hip replacement using second-generation components
Authors: McLaughlin J. R. , Lee K. R.
Published: December 2010

We reviewed 123 second-generation uncemented total hip replacements performed on 115 patients by a single surgeon between 1993 and 1994. The acetabular component used in all cases was a fully porous-coated threaded hemispheric titanium shell (T-Tap ST) with a calcium ion stearate-free, isostatically compression-moulded polyethylene liner. The titanium femoral component used was a Taperloc with a reduced distal stem. No patient was lost to follow-up. Complete clinical and radiological follow-up was obtained for all 123 hips at a mean of 14 years (12 to 16). One femoral component was revised after a fracture, and three acetabular components for aseptic loosening. No additional femoral or acetabular components were judged loose by radiological criteria. Mild proximal femoral osteolysis was identified in two hips and minor acetabular osteolysis was present in four. The mean rate of penetration of the femoral head was 0.036 mm/year (0.000 to 0.227).

These findings suggest that refinements in component design may be associated with excellent long-term fixation in cementless primary total hip replacement.
Injuries to the lower back in elite fast bowlers
Authors: Ranson C. A. , Burnett A. F. , Kerslake R. W.
Published: December 2010

In our study, the aims were to describe the changes in the appearance of the lumbar spine on MRI in elite fast bowlers during a follow-up period of one year, and to determine whether these could be used to predict the presence of a stress fracture of the posterior elements. We recruited 28 elite fast bowlers with a mean age of 19 years (16 to 24) who were training and playing competitively at the start of the study. They underwent baseline MRI (season 1) and further scanning (season 2) after one year to assess the appearance of the lumbar intervertebral discs and posterior bony elements. The incidence of low back pain and the amount of playing and training time lost were also recorded.

In total, 15 of the 28 participants (53.6%) showed signs of acute bone stress on either the season 1 or season 2 MR scans and there was a strong correlation between these findings and the later development of a stress fracture (p < 0.001). The prevalence of intervertebral disc degeneration was relatively low. There was no relationship between disc degeneration on the season 1 MR scans and subsequent stress fracture. Regular lumbar MR scans of asymptomatic elite fast bowlers may be of value in detecting early changes of bone stress and may allow prompt intervention aimed at preventing a stress fracture and avoiding prolonged absence from cricket.
The treatment of open femoral fractures with bone loss
Authors: Mitchell S. E. , Keating J. F. , Robinson C. M.
Published: December 2010

The results of the treatment of 31 open femoral fractures (29 patients) with significant bone loss in a single trauma unit were reviewed. A protocol of early soft-tissue and bony debridement was followed by skeletal stabilisation using a locked intramedullary nail or a dynamic condylar plate for diaphyseal and metaphyseal fractures respectively. Soft-tissue closure was obtained within 48 hours then followed, if required, by elective bone grafting with or without exchange nailing.

The mean time to union was 51 weeks (20 to 156). The time to union and functional outcome were largely dependent upon the location and extent of the bone loss. It was achieved more rapidly in fractures with wedge defects than in those with segmental bone loss. Fractures with metaphyseal defects healed more rapidly than those of comparable size in the diaphysis. Complications were more common in fractures with greater bone loss, and included stiffness of the knee, malunion and limb-length discrepancy.

Based on our findings, we have produced an algorithm for the treatment of these injuries. We conclude that satisfactory results can be achieved in most femoral fractures with bone loss using initial debridement and skeletal stabilisation to maintain length, with further procedures as required.
A critique of revision rate as an outcome measure
Authors: Goodfellow J. W. , O’Connor J. J. , Murray D. W.
Published: December 2010

National registers compare implants by their revision rates, but the validity of the method has never been assessed. The New Zealand Joint Registry publishes clinical outcomes (Oxford knee scores, OKS) alongside revision rates, allowing comparison of the two measurements. In the two types of knee replacement, unicompartmental (UKR) had a better knee score than total replacement (TKR), but the revision rate of the former was nearly three times higher than that of the latter. This was because the sensitivity of the revision rate to clinical failure was different for the two implants. For example, of knees with a very poor outcome (OKS < 20 points), only about 12% of TKRs were revised compared with about 63% of UKRs with similar scores.

Revision therefore is not an objective measurement and should not be used to compare these two types of implant. Furthermore, revision is much less sensitive than the OKS to clinical failure in both types and therefore exaggerates the success of knee replacements, particularly of TKR.
Vastus lateralis muscle flap for infected hips after resection arthroplasty
Authors: Suda A. J. , Heppert V.
Published: December 2010

We evaluated the potential of a vastus lateralis muscle flap in controlling infection after resection arthroplasty of the hip. We retrospectively reviewed 119 patients with 120 chronic infections after resection arthroplasty treated with this procedure. The flap was fixed with Mitek anchors in the acetabular cavity. The mean duration of infection after resection before the muscle flap procedure was 6.5 months (2 to 13). The patients had previously undergone a mean of 4.9 operations (2 to 25). In all patients the infected cavity was the origin of the persistent infection. The mean follow-up was for 2.6 years (1.0 to 4.7).

No patient had recurrent infection post-operatively and all had an improvement in the pain and better quality of life.
Four-limb compartment syndrome associated with the systemic capillary leak syndrome
Authors: Simon D. A. , Taylor T.-L. , Bayley G. , Lalonde K.-A.
Published: December 2010

Systemic capillary leak syndrome, or the Clarkson syndrome, is an extremely rare condition in which increased capillary permeability results in a massive shift of fluid into the extravascular space. This is followed rapidly by hypotensive shock, haemoconcentration, and, potentially, substantial oedema of the limbs resulting in an acute compartment syndrome. It is important for orthopaedic surgeons to be aware of this syndrome as our medical colleagues, who initially care for these patients, are less familiar with the diagnosis and the need for emergency management of the associated compartment syndrome should it develop. There have been fewer than 100 cases of this entity reported.

This case report is the first to describe the subsequent development of a compartment syndrome in all four limbs. Clinical vigilance and continuous monitoring of intracompartmental pressure is necessary in these patients in order to help reduce limb-threatening complications.
Coccydynia
Authors: Nathan S. T. , Fisher B. E. , Roberts C. S.
Published: December 2010

Coccydynia is a painful disorder characterised by coccygeal pain which is typically exaggerated by pressure. It remains an unsolved mystery because of the perceived unpredictability of the origin of the pain, some psychological traits that may be associated with the disorder, the presence of diverse treatment options, and varied outcomes. A more detailed classification based on the aetiology and pathoanatomy of coccydynia helps to identify patients who may benefit from conservative and surgical management.

This review focuses on the pathoanatomy, aetiology, clinical features, radiology, treatment and outcome of coccydynia.
Treatment of Meningitis Caused by Vancomycin-Resistant Enterococcus faecium: High-Dose and Combination Daptomycin Therapy
Authors: Le Jennifer , Bookstaver P Brandon , Rudisill Celeste N , Hashem Mohamed G , Iqbal Raza , James Charles L , Sakoulas George
Published: December 2010

Objective:

To report 3 successful treatments of vancomycin-resistant Enterococcus faecium meningitis in adults using daptomycin and either linezolid or gentamicin.

Case Summary:

Three case reports involving males (aged 58-78 years) are presented; in each case (trigeminal nerve microvascular decompression and subdural hygroma; paraspinal abscess; and hydrocephalus with subsequent craniotomy and ventriculo-peritoneal shunt placement) CSF examination revealed vancomycin-resistant Enterococcus (VRE) susceptible to daptomycin, gentamicin, and/or linezolid. Three- to four-week treatment regimens with daptomycin 6-12 mg/kg and either gentamicin or linezolid led to clinical resolution and microbiological clearance of infection.

Discussion:

Daptomycin has previously been shown to be successful in treating methicillin-resistant Staphylococcus aureus–associated meningitis and other serious VRE and enterococcal infections. Higher than approved doses of daptomycin were used in 2 cases where in theory higher CSF concentrations would thus be obtained. Gentamicin and linezolid were added to daptomycin therapy based on in vitro data synergy results and because of documented successful treatment for VRE meningitis, respectively.

Conclusions:

The difficulty in treating VRE CSF infections involves both drug kinetics and microbial resistance factors, as well as external factors such as foreign bodies like shunts. This report highlighted 3 cases where daptomycin use in concert with either gentamicin or linezolid was successful in treating this infection. Additional controlled trials will be helpful in identifying the best strategies when using daptomycin to treat CSF infections.
Drug Use Practices at Pediatric Hospitals of Khartoum State, Sudan
Authors: Ahmed Anas M , Awad Abdelmoneim I
Published: December 2010

Background:

Irrational drug utilization is a major concern in developing countries. The World Health Organization (WHO) has developed first-level informative indicators in assessing drug use practices and encouraging improvement in the quality of patient care.

Objective:

To assess the current drug use practices in 4 pediatric teaching hospitals in Khartoum State, and to compare the results with studies conducted in Sudan and other developing countries.

Methods:

A descriptive, quantitative, and cross-sectional study using the WHO drug use indicators methodology was conducted in the outpatient settings of 4 pediatric hospitals. The study sample was selected using systematic random sampling. In each hospital, prescribing was assessed through a collection of 150 prescriptions, determination of consultation time and dispensing time for 150 patients, and by interview of 150 patients for the evaluation of dispensing practices and parents' knowledge.

Results:

The mean number of drugs prescribed per prescription was 2.0 (95% CI 1.9 to 2.1); 49.3% (95% CI 46.3 to 52.4) were prescribed by generic name, 81.3% (95% CI 77.9 to 84.3) of prescriptions involved an antibiotic, and 3.5% (95% CI 2.2 to 5.4) of prescriptions were in injection form. The mean consultation and dispensing times were 4.7 minutes (95% CI 4.4 to 5.1) and 28.2 seconds (95% CI 26.5 to 29.9), respectively. The percentage of drugs actually dispensed was 80.1% (95% CI 77.9 to 82.2), 55.7% (95% CI 52.0 to 59.4) of drugs were adequately labeled, and 83.5% (95% CI 80.2 to 86.3) of parents knew the correct dosage of all drugs dispensed for their children. The percentage of availability of key drugs was 81.3% (95% CI 77.1 to 84.9). The essential medicines list was not available at the 4 hospitals.

Conclusions:

Our findings reveal problem areas in prescribing and dispensing practices in pediatric hospitals. Further in-depth quantitative research to answer the shortcomings of this study and cost-effective multifaceted interventions to improve current drug use practices are highly needed to secure the quality of medical care in pediatric hospitals.
Graphene oxide as surfactant sheets
Authors: Cote Laura J. , Kim Jaemyung , Tung Vincent C. , Luo Jiayan , Kim Franklin , Huang Jiaxing
Published: December 2010

Graphite oxide sheet, now referred to as graphene oxide (GO), is the product of chemical oxidation and exfoliation of graphite powders that was first synthesized over a century ago. Interest in this old material has resurged in recent years, especially after the discovery of graphene, as GO is considered a promising precursor for the bulk production of graphene-based materials. GO sheets are single atomic layers that can readily extend up to tens of microns in lateral dimension. Therefore, their structure bridges the typical length scales of both chemistry and materials science. GO can be viewed as an unconventional type of soft material as it carries the characteristics of polymers, colloids, membranes, and as highlighted in this review, amphiphiles. GO has long been considered hydrophilic due to its excellent water dispersity, however, our recent work revealed that GO sheets are actually amphiphilic with an edge-to-center distribution of hydrophilic and hydrophobic domains. Thus, GO can adhere to interfaces and lower interfacial energy, acting as surfactant. This new property insight helps to better understand GO’s solution properties which can inspire novel material assembly and processing methods such as for fabricating thin films with controllable microstructures and separating GO sheets of different sizes. In addition, GO can be used as a surfactant sheet to emulsify organic solvents with water and disperse insoluble materials such as graphite and carbon nanotubes (CNTs) in water, which opens up opportunities for creating functional hybrid materials of graphene and other π-conjugated systems.
On-Line Laser-Induced Breakdown Spectroscopy Determination of Magnesium Coating Thickness on Electrolytically Galvanized Steel in Motion
Authors: Ruiz Javier , González Alina , Cabalín Luisa María , Laserna José Javier
Published: December 2010

The application of laser-induced breakdown spectroscopy (LIBS) for online analysis of novel Zn based alloy coatings during continuous production of galvannealed steel has been demonstrated. Field trials were carried out at the ThyssenKrupp Steel (TKS) pilot plant in Dortmund, Germany. For this purpose, a portable LIBS demonstrator was constructed and evaluated, based on a dual-pulse Q-switched Nd:YAG laser, operated at 1064 nm. This system was used to generate plasmas on the moving sample surface after the annealing process, in order to control on-line the thickness of Mg on electrolytically galvanized steel. For variable Mg thicknesses (depending on strip speed of the pilot line, 100–1200 nm), and for steel sheets with a predetermined and constant Zn thickness (of 2 or 9 μm), a satisfactory agreement between plant LIBS measurements and data from laboratory chemical analysis (dissolution of the metallic coating and subsequent inductively coupled plasma–optical emission spectroscopy (ICP-OES) analysis) of Mg coating thicknesses has been obtained. The effects of environmental conditions on field measurements (strip temperature, mechanical vibrations, moisture on surface, etc.) have been demonstrated to be negligible, whereas minimal damage (crater diameters less than 150 μm) to the sample surface was caused.
Quality Evaluation of Polarization-Modulation Infrared Reflection—Absorption Spectra of a Langmuir Monolayer on Water Dependent on Angle of Incidence and Molecular Orientation
Authors: Itoh Yuki , Muro Maiko , Hasegawa Takeshi
Published: December 2010

Quality analysis of polarization-modulation infrared reflection–absorption spectrometry (PM-IRRAS) for measurements of a Langmuir (L) monolayer film on water is presented. The spectral quality represented by the signal-to-noise ratio is evaluated by taking into account both the band intensity and the electrical signal throughput led out from the Fourier transform infrared (FT-IR) spectrometer. The product of the two parameters, which is named the quality evaluation function, theoretically reveals the optimal angle of incidence for the L film measurements. In addition, the PM-IRRAS-specific surface selection rule with respect to the spectral quality is also presented.
Characterization of Pollen by Vibrational Spectroscopy
Authors: Zimmermann Boris
Published: December 2010

Classification, discrimination, and biochemical assignment of vibrational spectra of pollen samples belonging to 43 different species of the order Pinales has been made using three different vibrational techniques. The comparative study of transmission (KBr pellet) and attenuated total reflection (ATR) Fourier transform infrared (FT-IR) and FT-Raman spectroscopies was based on substantial variability of pollen grain size, shape, and relative biochemical composition. Depending on the penetration depth of the probe light, vibrational techniques acquire predominant information either on pollen grain walls (FT-Raman and ATR-FT-IR) or intracellular material (transmission FT-IR). Compared with the other two methods, transmission FT-IR obtains more comprehensive information and as a result achieves superior spectral identification and discrimination of pollen. The results strongly indicate that biochemical similarities of pollen grains belonging to the same plant genus or family lead to similar features in corresponding vibrational spectra. The exploitation of that property in aerobiological monitoring was demonstrated by simple and rapid pollen identification based on relatively small spectral libraries, with the same (or better) taxonomic resolution as that provided by optical microscopy. Therefore, the clear correlation between vibrational spectra and pollen grain morphology, biochemistry, and taxonomy is obtained, while successful pollen identification illustrates the practicability of such an approach in environmental studies.
Revisiting with Updated Hardware an Old Spectroscopic Technique: Circularly Polarized Luminescence
Authors: Castiglioni Ettore , Abbate Sergio , Longhi Giovanna
Published: December 2010

Among the various chiroptical spectroscopic techniques available today, circularly polarized luminescence (CPL) plays a minor role and is still used by a limited number of specialists. The cost of the few commercial instruments available and the complexity of homemade apparatuses have strongly limited the widespread application of this technique. New technological approaches, such as the use of light-emitting diode (LED) sources, may significantly simplify the required instrumentation and encourage new potential users. Calibration procedure and the quantitative determination of CPL and total luminescence intensity as well as the corresponding g ratio are described.
Temporal Sensitivity of the Wavelength Calibration of a Photodiode Array Spectrometer
Authors: Martinsen Paul , McGlone V. Andrew , Jordan Robert B. , Gaastra Paul
Published: December 2010

Subtle differences in the relationship between wavelength and pixel on photodiode array spectrometers contribute to difficulties in transferring calibrations from one instrument to another and may even introduce errors on a single instrument over time. To quantify the level of drift that might be expected in photodiode instruments, we calibrated the wavelength scale of two Zeiss MMS-1 photodiode spectrometers weekly over a 12-month period. We found no evidence of drift in the wavelength calibration. The wavelength calibration was consistent within 0.03 nm over at least 150 days and better than 0.1 nm over the year. To provide context for the wavelength accuracy, we applied small perturbations to wavelength in two partial least squares (PLS) models. We found that wavelength perturbations introduced a linear increase in bias of about 7%/nm (for example, a 1-nm perturbation shifted fruit dry matter prediction from 14% to 21%) in a kiwifruit dry-matter model and about 3.6 °C/nm in an Intralipid temperature model. By including small wavelength perturbations in the training sets, we were able to reduce this error to less than 1.7%/nm and 0.2 °C/nm in the dry-matter and temperature models, respectively. These results suggest that the wavelength scale of photodiode instruments can be very stable. However, in light of the high sensitivity of the PLS models we examined, we recommend testing and, where possible, mitigating the sensitivity of PLS models to small wavelength shifts.
Genetics of Type 2 Diabetes
Authors: Ahlqvist Emma , Ahluwalia Tarunveer Singh , Groop Leif
Published: December 2010

BACKGROUND

Type 2 diabetes (T2D) is a complex disorder that is affected by multiple genetic and environmental factors. Extensive efforts have been made to identify the disease-affecting genes to better understand the disease pathogenesis, find new targets for clinical therapy, and allow prediction of disease.

CONTENT

Our knowledge about the genes involved in disease pathogenesis has increased substantially in recent years, thanks to genomewide association studies and international collaborations joining efforts to collect the huge numbers of individuals needed to study complex diseases on a population level. We have summarized what we have learned so far about the genes that affect T2D risk and their functions. Although more than 40 loci associated with T2D or glycemic traits have been reported and reproduced, only a minor part of the genetic component of the disease has been explained, and the causative variants and affected genes are unknown for many of the loci.

Great advances have recently occurred in our understanding of the genetics of T2D, but much remains to be learned about the disease etiology. The genetics of T2D has so far been driven by technology, and we now hope that next-generation sequencing will provide important information on rare variants with stronger effects. Even when variants are known, however, great effort will be required to discover how they affect disease risk.
Supportive Leadership: Improving Organisational Health and Preventing Burnout in Pastoral Care Managers and Staff
Authors: Stebbins Peter , Lees Danielle , Ham David , Karabitsios Joanne
Published: December 2010

This study examined the efficacy of an evidence based supportive leadership program to address psychosocial hazards identified in an organisational health review of a pastoral care organisation. Participants were employees and volunteers identified as having supervisory or management roles (N= 24;M= 11,F= 13; Age Range = 24 to 68), including the Senior Leadership Team (SLT;n= 7). The supportive leadership program was implemented over a 12-month period with follow-up over another 12-month period. Organisational health was measured through the use of the Health and Safety Executive Indicator Tool (HSE, 2004b) and qualitative interview data at pre-intervention and at 12- and 24-month follow-up. The results of the HSE Tool were compared over time, utilising the comparison benchmarks provided by the HSE (2004b). Results indicated notable improvements in organisational health within the SLT with reductions in risk status at 24-month follow-up across the domains of Control, Managerial Support, Peer Support, Relationships, Role and Change. Supportive leadership is a key predictor in organisational health and burnout, and importance in improving organisational health across managers.