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Concept: Cyclic group


BACKGROUND: Leg pain associated with low back pain (LBP) is recognized as a risk factor for a poor prognosis, and is included as a component in most LBP classification systems. The location of leg pain relative to the knee and the presence of a positive straight leg raise test have been suggested to have clinical implications. To understand differences between such leg pain subgroups, and whether differences include potentially modifiable characteristics, the purpose of this paper was to describe characteristics of patients classified into the Quebec Task Force (QTF) subgroups of: 1) LBP only, 2) LBP and pain above the knee, 3) LBP and pain below the knee, and 4) LBP and signs of nerve root involvement. METHODS: Analysis of routine clinical data from an outpatient department. Based on patient reported data and clinical findings, patients were allocated to the QTF subgroups and described according to the domains of pain, activity limitation, work participation, psychology, general health and clinical examination findings. RESULTS: A total of 2,673 patients aged 18–95 years (median 47) who were referred for assessment of LBP were included. Increasing severity was consistently observed across the subgroups from LBP only to LBP with signs of nerve root involvement although subgroup differences were small. LBP patients with leg pain differed from those with LBP only on a wide variety of parameters, and patients with signs of nerve root involvement had a more severe profile on almost all measures compared with other patients with back-related leg pain. CONCLUSION: LBP patients with pain referral to the legs were more severely affected than those with local LBP, and patients with signs of nerve root involvement were the ones most severily affected. These findings underpin the concurrent validity of the Quebec Task Force Classification. However, the small size of many between-subgroup differences amid the large variability in this sample of cross-sectional data also underlines that the heterogeneity of patients with LBP is more complex than that which can be explained by leg pain patterns alone. The implications of the observed differences also require investigation in longitudinal studies.

Concepts: Longitudinal study, Epidemiology, Spinal disc herniation, Low back pain, Cross-sectional study, Cross-sectional analysis, Straight leg raise, Cyclic group


To evaluate the effectiveness of oral glucosamine in subgroups of people with hip or knee osteoarthritis (OA) based on baseline pain severity, body mass index (BMI), sex, structural abnormalities and presence of inflammation using individual patient data.

Concepts: Obesity, Mass, Rheumatoid arthritis, Osteoarthritis, Body mass index, Subgroup, Normal subgroup, Cyclic group


Preventive management of locust plagues works in some cases but still fails frequently. The role of funding institution awareness was suggested as a potential facilitating factor for cyclic locust plagues. We designed a multi-agent system to represent the events of locust plague development and a management system with three levels: funding institution, national control unit and field teams. A sensitivity analysis identified the limits and improvements of the management system.

Concepts: Bubonic plague, Locust, Cyclic group, Scientific modeling, Business terms, Plagues of Egypt


Study Design Randomized clinical trial. Background The recommended initial management strategy for these patients with low back pain and signs of nerve root compression is conservative treatment but there is little evidence to guide the most appropriate management strategy. Preliminary research suggests a treatment protocol of mechanical traction and extension-oriented exercises may be effective management, particularly in a specific sub-group of patients. Objective To examine the effectiveness of mechanical traction in patients with lumbar nerve root compression and within a pre-defined sub-group. Methods 120 patients with low back pain with nerve root compression were recruited from physical therapy clinics. Using pre-defined sub-grouping criteria, patients were stratified at baseline and randomized to receive an extension-oriented treatment approach (EOTA) with or without the addition of mechanical traction. During a 6-week period, patients received up to 12 treatment visits. Primary outcomes of pain and disability were collected at 6 weeks, 6 months and 1 year by assessors blinded to group allocation. Outcomes were examined using linear mixed model analyses examining change over time by treatment and the interaction between treatment and sub-grouping status. Results The mean age of participants was 41.1 (SD 11.3) years, median duration of symptoms was 62 days, and 57% were male. No significant differences in disability or pain outcomes were noted between treatment groups at any time point, nor was any interaction found between subgroup status and treatment. Conclusion Patients with lumbar nerve root compression presenting for physical can expect significant changes in disability and pain over a 6-week treatment period. There is no evidence mechanical lumbar traction in combination with an extension-oriented treatment is superior to extension-oriented exercises in management of these patients, nor within a predefined subgroups of patients. Level of Evidence Therapy, level 2b. J Orthop Sports Phys Ther, Epub 26 Jan 2016. doi:10.2519/jospt.2016.6238.

Concepts: Clinical trial, Spinal disc herniation, Evidence-based medicine, Randomized controlled trial, Group theory, Efficacy, Massage, Cyclic group


Purpose:To estimate the frequency of distorted presentation and overinterpretation of results in diagnostic accuracy studies.Materials and Methods:MEDLINE was searched for diagnostic accuracy studies published between January and June 2010 in journals with an impact factor of 4 or higher. Articles included were primary studies of the accuracy of one or more tests in which the results were compared with a clinical reference standard. Two authors scored each article independently by using a pretested data-extraction form to identify actual overinterpretation and practices that facilitate overinterpretation, such as incomplete reporting of study methods or the use of inappropriate methods (potential overinterpretation). The frequency of overinterpretation was estimated in all studies and in a subgroup of imaging studies.Results:Of the 126 articles, 39 (31%; 95% confidence interval [CI]: 23, 39) contained a form of actual overinterpretation, including 29 (23%; 95% CI: 16, 30) with an overly optimistic abstract, 10 (8%; 96% CI: 3%, 13%) with a discrepancy between the study aim and conclusion, and eight with conclusions based on selected subgroups. In our analysis of potential overinterpretation, authors of 89% (95% CI: 83%, 94%) of the studies did not include a sample size calculation, 88% (95% CI: 82%, 94%) did not state a test hypothesis, and 57% (95% CI: 48%, 66%) did not report CIs of accuracy measurements. In 43% (95% CI: 34%, 52%) of studies, authors were unclear about the intended role of the test, and in 3% (95% CI: 0%, 6%) they used inappropriate statistical tests. A subgroup analysis of imaging studies showed 16 (30%; 95% CI: 17%, 43%) and 53 (100%; 95% CI: 92%, 100%) contained forms of actual and potential overinterpretation, respectively.Conclusion:Overinterpretation and misreporting of results in diagnostic accuracy studies is frequent in journals with high impact factors.© RSNA, 2013Supplemental material:

Concepts: Statistics, Sample size, Measurement, Confidence interval, Statistical hypothesis testing, Subgroup, Statistical inference, Cyclic group


There is a continuing research interest in the muscle fiber type composition (MFTC) of athletes. Recently, muscle carnosine quantification by proton magnetic resonance spectroscopy ((1) H-MRS) was developed as a new non-invasive method to estimate MFTC. This cross-sectional study aims to better understand estimated MFTC in relation to (a) different disciplines within one sport; (b) cyclic sport exercise characteristics; © within-athlete variability; and (d) athlete level. A total of 111 elite athletes (74 runners, 7 triathletes, 11 swimmers, 14 cyclists and 5 kayakers) and 188 controls were recruited to measure muscle carnosine in gastrocnemius and deltoid muscle by (1) H-MRS. Within sport disciplines, athletes were divided into subgroups (sprint-, intermediate-, and endurance-type). The controls were used as reference population to allow expression of the athletes' data as Z-scores. Within different sports, endurance-type athletes systematically showed the lowest Z-score compared to sprint-type athletes, with intermediate-type athletes always situated in between. Across the different sports disciplines, carnosine content showed the strongest significant correlation with cyclic movement frequency (R = 0.86, P = 0.001). Both within and between different cyclic sports, estimated MFTC was divergent between sprint- and endurance-type athletes. Cyclic movement frequency, rather than exercise duration came out as the most determining factor for the optimal estimated MFTC in elite athletes.

Concepts: Spectroscopy, Muscle, Nuclear magnetic resonance, Estimation, In vivo magnetic resonance spectroscopy, Deltoid muscle, Cyclic group, Sport


The present study examined the presentation of autistic traits in a large adult population sample (n = 2,343). Cluster analysis indicated two subgroups with clearly distinguishable trait profiles. One group (n = 1,059) reported greater social difficulties and lower detail orientation, while the second group (n = 1,284) reported lesser social difficulties and greater detail orientation. We also report a three-factor solution for the autism-spectrum quotient, with two, related, social-themed factors (Sociability and Mentalising) and a third non-social factor that varied independently (Detail Orientation). These results indicate that different profiles of autistic characteristics tend to occur in the adult nonclinical population. Research into nonclinical variance in autistic features may benefit by considering social- and detail-related trait domains independently.

Concepts: Autism, Group, Group theory, Normal subgroup, Characteristic, Trait, Cyclic group, Generating set of a group


The division of medulloblastoma into different subgroups by microarray expression profiling has dramatically changed our perspective of this malignant childhood brain tumour. Now, the availability of next-generation sequencing and complementary high-density genomic technologies has unmasked novel driver mutations in each medulloblastoma subgroup. The implications of these findings for the management of patients are readily apparent, pinpointing previously unappreciated diagnostic and therapeutic targets. In this Review, we summarize the ‘explosion’ of data emerging from the application of modern genomics to medulloblastoma, and in particular the recurrent targets of mutation in medulloblastoma subgroups. These data are currently making their way into clinical trials as we seek to integrate conventional and molecularly targeted therapies.

Concepts: DNA, Medicine, Genetics, Cancer, Oncology, Brain tumor, DNA microarray, Cyclic group


This paper presents the effect of end groups, chain structure and stereocomplexation on the micro- and nano-particles morphology and thermal properties of the supramolecular triblock copolyesters. Therefore, the series of the triblock copolymers composed of L,L- and D,D-lactide, trimethylene carbonate (TMC) and ɛ-caprolactone (CL) with isopropyl (iPr) or 2-ureido-4-[1H]-pyrimidinone (UPy) end groups at both chain ends were synthesized. In addition, these copolymers were intermoleculary stereocomplexed by polylactide blocks with an opposite configuration of repeating units to promote their self-assembly in various organic solvents. The combination of two non-covalent interactions of the end groups and PLA enantiomeric chains leads to stronger interactions between macromolecules and allows for the alteration of their segmental mobility. The simple tuning of the copolymer microstructure and functionality induced the self-assembly of macromolecules at liquid-liquid interfaces, which leads consequence their phase separation in the form of particles with diameters ranging from 0.1 to 10 µm. This control is essential for their potential applications in the biomedical field in which biocompatible and well-defined micro- and nanoparticles are highly desirable.

Concepts: Polymer chemistry, Solubility, Nanotechnology, Chain, Acetic acid, Solvent, Ethyl acetate, Cyclic group


Toxoplasmosis is a zoonotic parasitic disease with worldwide distribution. Chitosan is a natural polymer which is commonly used in the production of nanomedicines. It is known to enable higher drug permeation, being biocompatible and has very low toxicity, besides its antimicrobial effects. Our study aimed to assess the effect of spiramycin-loaded chitosan nanoparticles (SLCNs) in treatment of acute and chronic toxoplasmosis in mice. 200 male Swiss albino mice were included in our study, divided to two main groups;Toxoplasma gondiiRH strain infected group and ME49 strain infected group, each main group was subdivided into four subgroups; subgroup I: infected control, subgroup II: infected and received chitosan nanoparticles (CS NPs); 20 µg of CS NPs in 100 µl of PBS/mouse/dose, subgroup III: infected and treated with spiramycin (Rovamycin); 100 mg/kg/day, subgroup IV: infected and treated with 100 mg/kg/day spiramycin-loaded chitosan nanoparticles. Effect of treatment was assessed parasitologically and histopathologically. It was noticed that SLCNs significantly decreased the mortality rate of infected mice with both strains compared to high mortality rate of mice in the infected control subgroups. Moreover, there was a significant decrease in the number of organisms of SLCNs treated subgroup as compared to the other subgroups. Histopathological studies showed a marked improvement of the pathological pictures of brain, liver, spleen and eye in the subgroup received SLCNs as opposed to other groups. In conclusion, the present study revealed that loading of spiramycin on chitosan nanoparticles increased its antiparasitic effect on acute and chronicT. gondiiinfection.

Concepts: Mortality rate, Group, Group theory, Order, Subgroup, Normal subgroup, Cyclic group, Index of a subgroup