Error consistency and the evaluation of treatment outcomes

The consistency/variability of error substitution patterns may hold important implications for subgrouping children with speech disorders, as well as for relationships between learning and generalization patterns. There is a need to quantify and examine the range of consistency/variability within the speech disordered population as it relates to system-wide change. This investigation compared two groups of preschool children (N = 10 each) differing in the consistency/variability of errors on a variety of pre-treatment and treatment outcome measures. The Error Consistency Index (ECI), a measure of error variability across the entire phonological system, was used to identify groups at the extreme ends of the ECI distribution from a larger participant pool. Each participant was treated on three target singletons from among obstruents /s, z, f, integral, tintegral, k, g/ and liquids /l, r/ and change on these targets, as well as their generalization to untrained positions was assessed. Although there were significant differences between the variable and consistent groups on all pre-treatment measures, there were no significant group differences in target and generalization learning or in per cent consonants correct (PCC) change. These findings provide evidence to suggest that relationships observed between error variability for individual phonemes and learning of those targets may differ from those observed when consistency/variability is quantified for the entire system and change across a number of phonemes, and the system as a whole, is examined.     

A genome-wide view of Caenorhabditis elegans base-substitution mutation processes

Knowledge of mutation processes is central to understanding virtually all evolutionary phenomena and the underlying nature of genetic disorders and cancers. However, the limitations of standard molecular mutation detection methods have historically precluded a genome-wide understanding of mutation rates and spectra in the nuclear genomes of multicellular organisms. We applied two high-throughput DNA sequencing technologies to identify and characterize hundreds of spontaneously arising base-substitution mutations in 10 Caenorhabditis elegans mutation-accumulation (MA)-line nuclear genomes. C. elegans mutation rate estimates were similar to previous calculations based on smaller numbers of mutations. Mutations were distributed uniformly within and among chromosomes and were not associated with recombination rate variation in the MA lines, suggesting that intragenomic variation in genetic hitchhiking and/or background selection are primarily responsible for the chromosomal distribution patterns of polymorphic nucleotides in C. elegans natural populations. A strong mutational bias from G/C to A/T nucleotides was detected in the MA lines, implicating oxidative DNA damage as a major endogenous mutagenic force in C. elegans. The observed mutational bias also suggests that the C. elegans nuclear genome cannot be at equilibrium because of mutation alone. Transversions dominate the spectrum of spontaneous mutations observed here, whereas transitions dominate patterns of allegedly neutral polymorphism in natural populations of C. elegans and many other animal species; this observation challenges the assumption that natural patterns of molecular variation in noncoding regions of the nuclear genome accurately reflect underlying mutation processes.     

Using Quality Improvement Techniques to Increase Colon Cancer Screening

Screening has been shown to be effective and cost-effective in reducing the incidence of, and mortality from, colorectal cancer. Despite its demonstrated efficacy, colon cancer screening remains underused, with fewer than 60% of age-eligible adults reporting being up to date with recommended screening tests. Several factors account for the low rates of utilization, including patient, provider and system-related issues. Several interventions have been shown to be effective in overcoming these barriers, including the use of patient decision aids. Patient decision aids are tools designed to provide information to patients about screening options, help them consider the pros and cons of the alternatives, and assist them to reach a decision consistent with their values. The use of decision aids in clinical practice can increase screening rates by up to 14 percentage points. Mailing the decision aids to patients in advance of office visits appears to be a cost-effective means of implementation.     

Somatosensory conflicts in complex regional pain syndrome type 1 and fibromyalgia syndrome

The somatosensory system is an integral component of the motor control system that facilitates the recognition of location and experience of peripheral stimuli, as well as body part position and differentiation. In chronic pain, this system may be disrupted by alterations in peripheral and cortical processing. Clinical symptoms that accompany such changes can be difficult for patients to describe and health care practitioners to comprehend. Patients with chronic pain conditions such as complex regional pain syndrome or fibromyalgia typically describe a diverse range of somatosensory changes. This article describes how sensory information processing can become disturbed in fibromyalgia syndrome and complex regional pain syndrome and how symptoms can potentially be explained by the mechanisms that generate them.     

Evaluation of distal symmetric polyneuropathy: The role of laboratory and genetic testing (an evidence‐based review)

Distal symmetric polyneuropathy (DSP) is the most common variety of neuropathy. Since the evaluation of this disorder is not standardized, the available literature was reviewed to provide evidence‐based guidelines regarding the role of laboratory and genetic tests for the assessment of DSP. A literature review using MEDLINE, EMBASE, Science Citation Index, and Current Contents was performed to identify the best evidence regarding the evaluation of polyneuropathy published between 1980 and March 2007. Articles were classified according to a four‐tiered level of evidence scheme and recommendations were based on the level of evidence. (1) Screening laboratory tests may be considered for all patients with polyneuropathy (Level C). Those tests that provide the highest yield of abnormality are blood glucose, serum B₁₂ with metabolites (methylmalonic acid with or without homocysteine), and serum protein immunofixation electrophoresis (Level C). If there is no definite evidence of diabetes mellitus by routine testing of blood glucose, testing for impaired glucose tolerance may be considered in distal symmetric sensory polyneuropathy (Level C). (2) Genetic testing is established as useful for the accurate diagnosis and classification of hereditary neuropathies (Level A). Genetic testing may be considered in patients with cryptogenic polyneuropathy who exhibit a hereditary neuropathy phenotype (Level C). Initial genetic testing should be guided by the clinical phenotype, inheritance pattern, and electrodiagnostic (EDX) features and should focus on the most common abnormalities, which are CMT1A duplication/HNPP deletion, Cx32 (GJB1), and MFN2 mutation screening. There is insufficient evidence to determine the usefulness of routine genetic testing in patients with cryptogenic polyneuropathy who do not exhibit a hereditary neuropathy phenotype (Level U). Muscle Nerve 39: 116–125, 2009     

Low cost polymer intramedullary nails for fracture fixation: a biomechanical study in a porcine femur model

Introduction  Whilst intramedullary nailing is a commonly accepted technique for lower limb fracture fixation, the cost of nails can be prohibitive in hospitals in developing nations. In these institutions bone cement has found many off label applications, that whilst are effective do not meet manufacturers guidelines. The aim of this study was to examine the biomechanics of one such application, fracture fixation using a bone cement intramedullary nail. Materials and methods  Five porcine femurs underwent a mid-shaft osteotomy and were fixed using a nail made from antibiotic simplex bone cement. The torsional and flexural stiffness and shear modulus of these constructs were compared to five intact porcine femurs. Results  The bone cement intramedullary nail was able to achieve relative stability in both torsion, with a mean shear modulus of 0.17 GPa and in flexion with a mean flexural stiffness of 358 N/mm. This corresponds to 47 and 22% of the respective measurements in the intact femurs. The mean ultimate flexural strength of fracture/nail constructs was 936 ± 350 N, which is 20% of the ultimate flexural strength of an intact porcine femur (4,820 ± 698 N). Conclusion  Intramedullary nails made from bone cement were able to provide sufficient promise in this situation to warrant further investigation for their applicability as a low cost alternative for use in developing countries.