Mass Spectrometry-Based Solid Phase Peptide Reaction Assay for Detecting Allergenicity Using an Immobilized Peptide-Conjugating Photo-Cleavable Linker.

The biological process of skin sensitization depends on the ability of a sensitizer to modify endogenous proteins. A direct peptide reactivity assay (DPRA), based on the biological process of skin sensitization, was developed as an alternative to controversial animal experiments. Although DPRA has been endorsed by industries and is internationally accepted as promising, it has several drawbacks, such as incompatibility with hydrophobic chemicals, inability to perform detailed reaction analysis, and ability to evaluate only single components. Here, we demonstrated that sensitizers and peptide adducts can be easily identified using a mass spectrometry-based solid-phase peptide reaction assay (M-SPRA). We synthesized peptides with a photo-cleavable linker immobilized on resins. We showed the potential of M-SPRA in predicting skin sensitization by measuring the peptide adducts that were selectively eluted from the resin after cleaving the linker post-reaction. M-SPRA provides more detailed information regarding chemical reactivity and accurate assessment of test samples, including mixtures. M-SPRA may be helpful for understanding the binding mechanism of sensitizers (toxicology), which may assist in further refining reactivity assays and aiding in the interpretation of reactivity data.

Outstanding Elastic Limit of a Thin Film Composed of Nickel Nanosprings.

This paper presents experimental results of vertical loading using an atomic force microscope (AFM) performed on a thin film consisting of nickel helical nanoelements (nanosprings) formed by glancing angle deposition (GLAD) technique. As a helical element has large reversible deformation limit in general, a characteristic behavior is expected on the yielding of the film. From the load versus displacement curves, we find the outstanding elastic limit of nickel nanosprings film. The apparent yield strain is evaluated as ε' Y = 5.2˜6.2 × 10−2, which is around 200 times of that in bulk nickel (ε Y = 0.29˜0.44 × 10−3). However, comparing the maximum shear stress in the helical spring and the solid film, the shape effect (helical shape) is only around 10˜20 times stemmed from the difference in the stress condition (torsion). The origin of difference is attributed to the size effect of nanosprings, as nano-scale metals have higher yield strain than that of bulk counterpart because of the difference in the understructure morphology. The combination of shape effect and size effect brings about the giant elastic limit on the film.

Peer-assisted learning--beyond teaching: How can medical students contribute to the undergraduate curriculum?

INTRODUCTION: Peer-assisted learning (PAL) has become increasingly popular over recent years with many medical schools now formally incorporating peer-teaching programs into the curriculum. PAL has a sound evidence base with benefit to both peer-teacher and peer-learner. Aside from in teaching delivery, empowering students to develop education in its broadest sense has been much less extensively documented. CASE STUDIES: Five case studies with supportive evaluation evidence illustrate the success of a broad range of peer-led projects in the undergraduate medical curriculum, particularly where these have been embedded into formal teaching practices. DISCUSSION: These case studies identify five domains of teaching and support of learning where PAL works well: teaching and learning, resource development, peer-assessment, education research and evaluation and mentoring and support. Each case offers ways of engaging students in each domain. CONCLUSIONS: Medical students can contribute significantly to the design and delivery of the undergraduate medical program above and beyond the simple delivery of peer-assisted "teaching". In particular, they are in a prime position to develop resources and conduct research and evaluation within the program. Their participation in all stages enables them to feel involved in course development and education of their peers and ultimately leads to an increase in student satisfaction.

Do peer-tutors perform better in examinations? An analysis of medical school final examination results.

CONTEXT: Peer-assisted learning (PAL) is recognised as an effective learning tool and its benefits are well documented in a range of educational settings. Learners find it enjoyable and their performances in assessments are comparable with those of students taught by faculty tutors. In addition, PAL tutors themselves report the development of improved clinical skills and confidence through tutoring. However, whether tutoring leads to actual improvement in performance has not been fully investigated. OBJECTIVES: As high-achieving students are already en route to succeeding in final examinations, we wanted to examine whether participation in a peer-tutoring programme in itself leads to better final-year examination performance. METHODS: We conducted a retrospective analysis of results on final-year written and clinical examinations at University College London Medical School during 2010-2012. Z-scores were calculated and the performances of PAL tutors and students who were not PAL tutors were compared using analysis of covariance (ancova). Year 4 examination results were used as indicators of previous academic attainment. RESULTS: Of the 1050 students who attempted the final examination, 172 were PAL tutors in the final year. Students who acted as PAL tutors outperformed students who did not in all examination components by 1-3%. Z-scores differed by approximately 0.2 and this was statistically significant, although the significance of this difference diminished when controlling for Year 4 results. Students who acted as PAL tutors who had scored in the top quartile in Year 4 examinations scored significantly better in a long-station objective structured clinical examination (LSO). CONCLUSIONS: Although students who acted as PAL tutors performed better than students who did not in final-year examinations, this difference was small and attributable to the students' background academic abilities. High-achieving students appear to be self-selecting as peer-tutors and their enhanced performance in LSOs may reflect their inherent academic abilities. Although peer-tutoring in itself did not lead to enhanced examination performance, further studies are required as many factors, such as the proximity of examinations and previous tutoring, can potentially affect the relationship between peer-tutoring experience and examination performance.

Learning through work: clinical shadowing of junior doctors by first year medical students.

BACKGROUND: Early clinical contact (ECC) is a key feature of undergraduate programmes, yet they make significant demands on senior clinicians delivering it and usually focus on patient contact. AIMS: To explore the potential of an ECC activity oriented to work as a junior doctor and the clinical environment, and the use of very junior doctors as facilitators of this learning. METHODS: For two academic years, all first year medical students at UCL Medical School shadowed a Foundation Year (FY) doctor for a four-hour shift to experience and understand the work of junior doctors. Feedback from students and FY doctors was gathered and analysed. RESULTS: The students found the FY doctors to be good near-peer tutors and enjoyed exploring the clinical environment, but felt that the unstructured learning environment was difficult. The FY doctors felt that learning in and about the clinical environment was an important learning outcome for the students, although they found supervising junior medical students in a shadowing context difficult. CONCLUSIONS: FY doctors are an effective and under-utilised resource in introducing novices to the role of a medical professional in the clinical environment; however students and FY doctors need support to maximise the learning potential of early shadowing activities.

Isolation of uracil auxotrophs of the fungus Acremonium cellulolyticus and the development of a transformation system with the pyrF gene.

Acremonium cellulolyticus CF-2612 is a cellulase hyper-producing mutant that originated from A. cellulolyticus Y-94. In this study, we isolated a uracil auxotroph (strain CFP3) derived from CF-2612, and cloned a wild-type pyrF gene encoding orotate phosphoribosyl transferase (OPRTase) from Y-94. OPRTase activity was not detected in strain CFP3, which had one nucleotide substitution in its pyrF gene. The wild-type pyrF gene restored the defective growth of CFP3 on uracil-free medium, and PCR and Southern analyses revealed that wild-type pyrF was integrated into the genome. These results indicate that our transformation system for A. cellulolyticus with the pyrFgene as a selection marker was successful.

Little gene flow between domestic silkmoth Bombyx mori and its wild relative Bombyx mandarina in Japan, and possible artificial selection on the CAD gene of B. mori.

We analyzed PCR-amplified carbamoyl-phosphate synthetase 2, aspartate transcarbamylase, and dihydroorotase (CAD) gene fragments from 146 Bombyx mori native strains and found extremely low levels of DNA polymorphism. Two haplotypes were identified, one of which was predominant. CAD haplotype analysis of 42 samples of Japanese B. mandarina revealed four haplotypes. No common haplotype was shared between the two species and at least five base substitutions were detected. This result was suggestive of low levels of gene flow between the two species. The nucleotide diversity (π) scores of the two samples differed markedly: lower π values were estimated for B. mori native strains than Japanese B. mandarina. We further analyzed 12 Chinese B. mandarina derived from seven areas of China, including Taiwan. The results clearly indicated that the π score was ~80-fold greater in Chinese B. mandarina than in B. mori. The extremely low level of DNA polymorphism in B. mori compared to its wild relatives suggested that the CAD gene itself or its tightly linked regions are possible targets for silkworm domestication.

Adjunctive gabapentin for treatment-resistant insomnia of bipolar disorder: a case report.

We report a case with bipolar II disorder having mixed features, in which refractory insomnia persisted. We diagnosed his case as mixed depression with mood fluctuations because increased impulsivity and buying sprees became remarkable, with diminished ability to think or concentrate. Switching to carbamazepine and risperidone improved his mood fluctuations and impulsivity. Nevertheless, his intermittent awakening (fragmentation of the sleep-wake rhythm), related dysfunctional beliefs, anxiety about sleep, and mild impulsivity persisted. The addition of various benzodiazepine sleeping drugs, bromovalerylurea, and antipsychotics did not improve insomnia. His intractable insomnia was markedly responsive to gabapentin, engendering further improvement of mood symptoms. Eventually, its efficacy achieved his reinstatement at work. Results of this case suggest the clinical use of gabapentin for treating bipolar disorder, especially in cases with intractable insomnia, which is a very important point in the symptoms and therapeutics of bipolar disorder.

Insight and other predictors of physical examination refusal in psychotic illness.

BACKGROUND: Poor physical health in psychiatric patients is well recognized, yet factors contributing to physical examination noncompliance in psychotic illness have not been previously studied. AIM: To examine whether insight or any other variables were independent predictors of physical examination noncompliance. METHOD: A case-note study (N = 200) of inpatient psychiatric patients in four hospitals in London, UK was conducted to examine the relationship between insight and physical examination noncompliance within 24 h of admission and over 2 weeks. Clinical variables including illness severity were also examined. RESULTS: Patients who were noncompliant with physical examinations offered within 24 h and over 2 weeks were associated with lack of insight, higher illness severity, female gender, longer history of illness, current compulsory admission, and previous history of detention. After adjusting for confounding factors, lack of insight, female gender, and previous history of detention were found to be independent predictors of physical examination noncompliance for 24 h and 2 weeks. CONCLUSION: Lack of insight is highly predictive of physical examination noncompliance for up to 2 weeks, indicating that mental incapacity to consenting to medical care may be common and that more proactive physical screening may be required for these patients.

Noninvasive diagnosis of ischemic and nonischemic cardiomyopathy using coronary flow velocity measurements of the left anterior descending coronary artery by transthoracic Doppler echocardiography.

OBJECTIVES: The purpose of this study was to assess the feasibility and usefulness of coronary flow velocity measurements of the left anterior descending coronary artery (LAD) by transthoracic Doppler echocardiography (TTDE) to differentiate ischemic cardiomyopathy (ICM) from non-ICM in patients. BACKGROUND: ICM and non-ICM have similar 2-dimensional echocardiographic features, left ventricular dilatation, and diffuse wall-motion abnormalities. TTDE may be useful to differentiate ICM from non-ICM by detecting significant LAD stenosis based on LAD flow signal analysis. METHODS: TTDE was performed in 52 consecutive patients with left ventricular dilatation and diffuse wall-motion abnormalities of unknown origin. Peak and averaged systolic and diastolic flow velocities of the distal LAD flow could be recorded and measured from 44 patients (85%). Peak and mean diastolic/systolic velocity ratio (DSVR) were calculated. RESULTS: By coronary angiogram, 13 patients were given the diagnosis of ICM and 31 of non-ICM. Left ventricular end-diastolic and end-systolic volumes and ejection fraction were similar between ICM and non-ICM. On the other hand, peak DSVR (1.47 +/- 0.38 vs 2.34 +/- 0.67, P < .0001) and mean DSVR (1.40 +/- 0.42 vs 2.24 +/- 0.61, P < .0001) were significantly lower in patients with ICM than non-ICM. Either peak DSVR less than 1.8 or mean DSVR less than 1.8 had a sensitivity of 77% and a specificity of 77% for detecting the presence of severe LAD stenosis and, therefore, the diagnosis of ICM. CONCLUSION: TTDE is a useful noninvasive method to differentiate ICM from non-ICM.

Development of a three-year-old child FE model.

OBJECTIVE: Child crash dummies are conventionally used for safety performance evaluations of the child restraint system (CRS) in vehicle crash tests. To investigate injuries to various body regions of a child in detail, mathematical models are useful, and provide information that cannot be analyzed by crash dummies. Therefore, in the present research, a finite element (FE) model of a 3-year-old child has been developed by model-based scaling from the AM50 human FE model, THUMS (Total HUman body for Safety). METHODS: The dimensions of each body region were based on the anthropometry data of United States children, and material properties of child bone were estimated from data reported in the literature. Neck flexion, thorax impact responses, and torso flexion were validated against the response corridor of the 3-year-old Hybrid III dummy in calibration tests. A test of lap belt loading to the abdomen was also conducted. FE models of two different types of CRS, a 5-point harness and a tray shield CRS, were also made, and ECE R44 sled impact test simulations were conducted using the child FE model. RESULTS: The characteristics of the child FE model proved to be close to the Hybrid III and child volunteer corridor. In the ECE R44 sled test simulations using the child FE model, the head movement down and head rotation were large in the 5-point harness CRS, and chest deflection was large in the tray shield CRS. In both CRS types, the whole spine flexed in the child FE model. This behavior is different from that of the Hybrid III, where the thorax spine is stiff and only the cervical spine and lumbar spine flex. CONCLUSIONS: Although this child FE model has several limitations in areas such as the anatomical shapes and material properties of a child, this model can be a useful tool to examine the behavior of a child in impacts, which may be difficult to predict by using the Hybrid III dummy with its stiff thorax spine box.