Corticospinal tract asymmetry and handedness in right- and left-handers by diffusion tensor tractography

Purpose

Cerebral hemispheres represent both structural and functional asymmetry, which differs among right- and left-handers. The left hemisphere is specialised for language and task execution of the right hand in right-handers. We studied the corticospinal tract in right- and left-handers by diffusion tensor imaging and tractography. The present study aimed at revealing a morphological difference resulting from a region of interest (ROI) obtained by functional MRI (fMRI).

Methods

Twenty-five healthy participants (right-handed: 15, left-handed: 10) were enrolled in our assessment of morphological, functional and diffusion tensor MRI. Assessment of brain fibre reconstruction (tractography) was done using a deterministic algorithm. Fractional anisotropy (FA) and mean diffusivity (MD) were studied on the tractography traces of the reference slices.

Results

We observed a significant difference in number of leftward fibres based on laterality. The significant difference in regard to FA and MD was based on the slices obtained at different levels and the laterality index. We found left-hand asymmetry and right-hand asymmetry, respectively, for the MD and FA.

Conclusions

Our study showed the presence of hemispheric asymmetry based on laterality index in right- and left-handers. These results are inconsistent with some studies and consistent with others. The reported difference in hemispheric asymmetry could be related to dexterity (manual skill).     

Benefits of Hippotherapy and Horse Riding Simulation Exercise on Healthy Older Adults: A Systematic Review

Objective

To provide an up-to-date research analysis on equine-assisted therapies and horse riding simulation exercise in older adults, and to suggest future directions in clinical practice and research.

A formalized mentoring program for LPN-to-RN students

Nursing programs across the United States are faced with the challenge to admit greater numbers of students and improve retention and progression rates of enrolled students. Associate degree nursing (ADN) programs produce the largest percentage of registered nurse (RN) graduates in comparison with other basic RN programs (National League for Nursing, 2006). Many states and academic institutions have begun to realize that the large pool of licensed practical nurses (LPNs) is a viable source of quality ADN students. LPN students in LPN-to-RN completion programs can often complete degrees and be eligible to take state board RN examinations in half the time of a traditional ADN student. Faculty at Ohio University-Chillicothe (OU-C) examined strategies to enhance the LPN-to-RN transition program on the campus and to promote retention and progression of this unique population of nursing students in the ADN program. The faculty researchers developed the Nursing Success program after a review of the literature and with support from an internal grant from the OU-C Faculty Summer Research Fund. This article describes this formalized, faculty-driven student mentoring program designed for LPN-to-RN students at OU-C and the outcomes of the initial implementation.     

Efficient Detection of Carbapenemase Activity in Enterobacteriaceae by Matrix-Assisted Laser Desorption Ionization?Time of Flight Mass Spectrometry in Less Than 30 Minutes

The recognition of carbapenemase-producing Enterobacteriaceae (CPE) isolates is a major laboratory challenge, and their inappropriate or delayed detection may have negative impacts on patient management and on the implementation of infection control measures. We describe here a matrix-assisted laser desorption ionization−time of flight (MALDI-TOF)-based method to detect carbapenemase activity in Enterobacteriaceae. After a 20-min incubation of the isolate with 0.5 mg/ml imipenem at 37°C, supernatants were analyzed by MALDI-TOF in order to identify peaks corresponding to imipenem (300 Da) and an imipenem metabolite (254 Da). A total of 223 strains, 77 CPE (OXA-48 variants, KPC, NDM, VIM, IMI, IMP, and NMC-A) and 146 non-CPE (cephalosporinases, extended-spectrum β-lactamases [ESBLs], and porin defects), were tested and used to calculate a ratio of imipenem hydrolysis: mass spectrometry [MS] ratio = metabolite/(imipenem + metabolite). An MS ratio cutoff was statistically determined to classify strains as carbapenemase producers (MS ratio of ≥0.82). We validated this method first by testing 30 of our 223 isolates (15 CPE and 15 non-CPE) 10 times to calculate an intraclass correlation coefficient (ICC of 0.98), showing the excellent repeatability of the method. Second, 43 strains (25 CPE and 18 non-CPE) different from the 223 strains used to calculate the ratio cutoff were used as external controls and blind tested. They yielded sensitivity and specificity of 100%. The total cost per test is <0.10 U.S. dollars (USD). This easy-to-perform assay is time-saving, cost-efficient, and highly reliable and might be used in any routine laboratory, given the availability of mass spectrometry, to detect CPE.     

Molecular typing of Mycobacterium tuberculosis by mycobacterial interspersed repetitive unit-variable-number tandem repeat analysis, a more accurate method for identifying epidemiological links between patients with tuberculosis

IS6110 fingerprinting of Mycobacterium tuberculosis is the standard identification method in studies on transmission of tuberculosis. However, intensive epidemiological investigation may fail to confirm transmission links between patients clustered by IS6110-restriction fragment length polymorphism (RFLP) typing. We applied typing based on variable numbers of tandem repeats (VNTRs) of mycobacterial interspersed repetitive units (MIRUs) to isolates from 125 patients in 42 IS6110 clusters, for which thorough epidemiological data were available, to investigate the potential of this method in distinguishing epidemiologically linked from nonlinked patients. Of seven IS6110 clusters without epidemiological links, five were split by MIRU-VNTR typing, while nearly all IS6110 clusters with proven or likely links displayed conserved MIRU-VNTR types. These results provide molecular evidence that not all clusters determined on the basis of multibanded IS6110 RFLP patterns necessarily reflect transmission of tuberculosis. They support the use of MIRU-VNTR typing as a more reliable and faster method for transmission analysis.     

Antibody response in pulmonary tuberculosis against recombinant 27kDa (MPT51, Rv3803c) protein of Mycobacterium tuberculosis

The objective of this study is to evaluate the recombinant 27kDa (MPT51, Rv3803c) antigen of M. tuberculosis H37Rv, expressed in E. coli in enzyme linked immunosorbent assays (ELISA) to estimate the IgG, IgA and IgM levels in sera from adult pulmonary tuberculosis patients and control groups. Sera from smear and culture positive tuberculosis patients (S + C +) were positive for anti-MPT51 IgG, IgA and IgM, with a sensitivity of 57%, 47% and 13%, respectively. The sensitivity of the test improved to a level of 71% for IgG+IgA without significantly compromising the specificity (IgG of 98%, IgG+IgA of 95%). Addition of IgM results did not enhance the sensitivity appreciably, over and above that of IgG+IgA (72% vs 71%). Among the smear-negative but culture-positive cases (S-C+), 34% were positive for IgG, while in smear and culture-negative but X-ray-positive cases (S-C-), 42% were positive for IgG. Polyethylene glycol precipitation (PEG) of the circulating immune complex (CIC) in sera was carried out. The CIC-bound antibodies to MPT51 were assessed using ELISA. Measuring the IgG+IgA combination positivities of the CIC-bound antibodies gave a poor sensitivity of 21%, 18% and 10%, respectively. The specificity of the assay by these combinations was maintained at 94%.     

Evaluation of a real-time fluorescent PCR assay for rapid detection of Group B Streptococci in neonatal blood

Streptococcus agalactiae (Group B Streptococcus: GBS) is the major causative agent of neonatal sepsis. Neonates at risk for GBS infections are empirically administered broad-spectrum antibiotics for at least 48 h pending blood culture results. A rapid assay to expedite detection of GBS would facilitate initiation of specific antibiotic therapy. Conversely, expeditious proof of absence of infection will avoid unnecessary antibiotic use. Using the LightCycler, we evaluated a hybridization probe polymerase chain reaction (PCR) assay to detect GBS-specific cfb gene target DNA sequence in blood specimens. Both sensitivity and specificity of the real-time PCR assay was 100%. The assay demonstrated 100% specificity when tested against 26 non-GBS bacteria. This method is capable of detecting as few as approximately 100 copies or 10 pg of GBS genomic DNA. This real-time PCR method is rapid, sensitive, and specific for the detection of GBS in neonatal blood samples and holds great promise in its utility in the diagnostic laboratory.