Evaluation of dosage, safety and effects of methylphenidate on post-traumatic brain injury symptoms with a focus on mental fatigue and pain

OBJECTIVE

The neurobehavioural symptoms and pain following traumatic brain injury (TBI) can be long-lasting. The condition impairs the persons' ability to function in their work, studies and gatherings with family and friends. The aim of this study was to investigate dosage, safety and effects of methylphenidate on mental fatigue and pain.

METHODS

Twenty-nine physically-well rehabilitated TBI victims, 28 with a mild TBI and one with TBI and also with pain in the neck, shoulders and head were included in the study. Methylphenidate was tested in each patient using three treatment strategies: no medication, low dose (5 mg × 3) and normal dose (20 mg × 3) for 4 weeks using a randomized cross-over design.

RESULTS

Twenty-four patients completed the three treatment periods. Five participants discontinued, four females due to adverse reactions and one male due to attenuated motivation. Only minor adverse events were reported. Methylphenidate significantly decreased mental fatigue, as evaluated by the Mental Fatigue Scale (p < 0.001), and the effects on mental fatigue were dose-dependent. No effect on pain was detected.

CONCLUSIONS

Methylphenidate decreased mental fatigue for subjects suffering a traumatic brain injury, the treatment is considered to be safe and is recommended, starting with a low dose.

The influence of intensity and duration of a painful conditioning stimulation on conditioned pain modulation in volunteers

BACKGROUND AND METHOD

The aim was to investigate influence from variations in intensity of a painful conditioning stimulation (CS) on early (0-6 min) and prolonged (6-12 min) conditioned pain modulation (CPM) in volunteers during concurrent exposure to test stimuli (TS). CS was applied to either forearm using painful heat with an intensity of 2/10 and 5/10, respectively, rated on a 0-10 numerical pain rating scale. At a second session, CS with an intensity of 7/10 was applied to the arm using a tourniquet. Threshold and suprathreshold painful heat and pressure as well as painful repeated monofilament pricking (RMP) were assessed as TS.

RESULTS

Regardless of TS, there was no significant difference in the magnitude of CPM within the same stimulus modality during the various intensities and phases of the CS. Significant modulation of heat pain thresholds (HPTs) was found during the early phase at 5/10 and 7/10, but not at 2/10. Only at 5/10 the prolonged CS resulted in a significant additional increase in HPT. During the early CS phase, CPM of suprathreshold heat pain was found at 2/10 and 5/10. The prolonged CS resulted in a significant additional temperature increase at 5/10. Only during the early phase significant CPM of pressure pain thresholds were found for all three pain intensities in conjunction with a significant CPM of suprathreshold pressure pain at 5/10. There was no CPM of RMP.

CONCLUSION

The CS intensity and the duration of CPM modulated pain sensitivity differentially across TS modalities.

Adhesion of the iron-chromium oxide interface from first-principles theory

We determine the interface energy and the work of separation of the Fe/Cr2O3 interface using first-principles density functional theory. Starting from different structures, we put forward a realistic interface model that is suitable to study the complex metal-oxide interaction. This model has the lowest formation energy and corresponds to an interface between Fe and oxygen terminated Cr2O3. The work of separation is calculated to be smaller than the intrinsic adhesion energy of pure Fe or Cr2O3, suggesting that stainless steel surfaces should preferentially break along the metal-oxide interface. The relative stabilities and magnetic interactions of the different interfaces are discussed. Next we introduce Cr atoms into the Fe matrix at different positions relative to the interface. We find that metallic Cr segregates very strongly to the (FeCr)/Cr2O3 interface, and increases the separation energy of the interface, making the adhesion of the oxide scale mechanically more stable. The Cr segregation is explained by the enthalpy of formation.

The MX4blaster cassette: repeated and clean Saccharomyces cerevisiae genome modification using the genome-wide deletion collection

The kanMX4 resistance marker is widely used for Saccharomyces cerevisiae gene deletion and has been used to create a genome-wide deletion mutant collection. Transfer of PCR-amplified marker loci from collection mutants is a very efficient way of introducing mutations into other S. cerevisiae strains of interest. An important limitation of this strategy is that the kanMX4 marker is not easily removed, impairing the construction of multiple gene deletion strains. The MX4blaster is a novel MX4-compatible cassette that facilitates clean or scarless kanMX4 removal. The MX4blaster cassette efficiently replaces the kanMX4 cassette due to shared promoter and terminator sequences. The MX4blaster cassette is removed by the induction of an internal double-stranded break and transformation with a DNA fragment designed to recombine on either side of the cassette in combination with counter selection. Simple and inexpensive media are used for induction and counter selection, mitigating the use of expensive chemicals. Routinely, thirty percent of transformants successfully removed the MX4blaster cassette. The resulting mutants contain no trace of the MX4blaster cassette. The unique properties of the MX4blaster cassette make it an important addition to S. cerevisiae genetic tools, especially in combination with the genome-wide deletion collection.

Surface parameters of ferritic iron-rich Fe-Cr alloy

Using first-principles density functional theory in the implementation of the exact muffin-tin orbitals method and the coherent potential approximation, we studied the surface energy and the surface stress of the thermodynamically most stable surface facet (100) of the homogeneous disordered body-centred cubic iron-chromium system in the concentration interval up to 20 at.% Cr. For the low-index surface facets of Fe and Cr, the surface energy of Cr is slightly larger than that of Fe, while the surface stress of Cr is considerably smaller than that of Fe. We find that Cr addition to Fe generally increases the surface energy of the Fe-Cr alloy; however, an increase of the bulk amount of Cr also increases the surface stress. As a result of this unexpected trend, the (100) surface of Fe-Cr becomes more stable against reconstruction with increasing Cr concentration. We show that the observed trends are of magnetic origin. In addition to the homogeneous alloy case, we also investigated the impact of surface segregation on both surface parameters.

Differential Effects on ERP Post-Adoption Stages across Scandinavian and Iberian SMEs

Enterprise resource planning (ERP) post-adoption stages (use and value) and small and medium enterprises (SME) are of high interest among both academics and practitioners. Grounded in the diffusion of innovation theory to explain ERP use and resource-based view theory to explain ERP value the authors postulate that use is an important link to value. The authors propose and test a model using a unique dataset of 883 SMEs from Scandinavia and Iberia. Whereas for both regions, competitive pressure, efficiency, and best-practices are important factors to use ERP, analytics and collaboration are important factors for ERP value. Whereas complexity and training are not relevant for ERP use among Scandinavian SMEs, they are facilitators for Iberian firms. This is an empirical theoretically grounded research studying ERP use and value among SMEs across two distinct European regions, thus adding an international dimension to the IS literature, as well moving beyond dichotomous “adoption versus non-adoption”.

Involvement of A1Adenosine Receptors in the Acquisition of Fertilizing Capacity

Ejaculated mammalian spermatozoa acquire competence to fertilize oocytes by a two-step process: capacitation followed by acrosome reaction. The biochemical and biophysical modifications occurring in vivo in the female reproductive tract can be reproduced in vitro, and previous studies have suggested a capacitative role for adenosine A(1) receptor (A(1)R). Mice with a targeted disruption of the Adora 1 gene (A(1)R-/- mice) provide a useful model for better understanding the role of the A(1)R in fertility. Murine spermatozoa express A(1)R in the head, neck, midpiece region, and tail. The number of capacitated spermatozoa incubated in human tubal fluid was significantly reduced in A(1)R-/- compared with A(1)R+/+ and A(1)R+/- spermatozoa. The difference between A(1) R+/+ and A(1)R-/- mouse spermatozoa was mainly in the time necessary to reach the maximum percentage of capacitation. A(1)R+/+ murine sperm obtained the full state of capacitation within 90 minutes whereas A(1)R-/- sperm required 240 minutes. Caffeine, a known antagonist of A(1) and A(2A) adenosine receptors, lowered the number of capacitated sperm and affected the time of capacitation in a dose-dependent manner, mimicking the effects of the lack of A(1) receptors. Although number, motility, and viability of A(1)R-/- murine sperm was not significantly different from A(1)R+/+ mouse spermatozoa, a significant reduction of the number of pups produced by A(1)R-/- male mice suggests that A(1) receptors must be fully operative to accomplish the optimal degree of capacitation and thereby fertilization.

Localization of cholesterol, amyloid and glia in Alzheimer's disease transgenic mouse brain tissue using time-of-flight secondary ion mass spectrometry (ToF-SIMS) and immunofluorescence imaging

The spatial distributions of lipids, amyloid-beta deposits, markers of neurons and glial cells were imaged, at submicrometer lateral resolution, in brain structures of a mouse model of Alzheimer's disease using a new methodology that combines time-of-flight secondary ion mass spectrometry (ToF-SIMS) and confocal fluorescence microscopy. The technology, which enabled us to simultaneously image the lipid and glial cell distributions in Tg2576 mouse brain structures, revealed micrometer-sized cholesterol accumulations in hippocampal regions undergoing amyloid-beta deposition. Such cholesterol granules were either associated with individual amyloid deposits or spread over entire regions undergoing amyloidogenesis. Subsequent immunohistochemical analysis of the same brain regions showed increased microglial and astrocytic immunoreactivity associated with the amyloid deposits, as expected from previous studies, but did not reveal any particular astrocytic or microglial feature correlated with cholesterol granulation. However, dystrophic neurites as well as presynaptic vesicles presented a distribution similar to that of cholesterol granules in regions undergoing amyloid-beta accumulation, thus indicating that these neuronal endpoints may retain cholesterol in areas with lesions. In conclusion, the present study provides evidence for an altered cholesterol distribution near amyloid deposits that would have been missed by several other lipid analysis methods, and opens for the possibility to study in detail the putative liaison between lipid environment and protein structure and function in Alzheimer's disease.

Cochlear implant combined with a linear frequency transposing hearing aid

BACKGROUND

Adults with cochlear implants (CIs) are usually implanted unilaterally. To preserve binaural advantages, a noninvasive method involves maintaining the hearing aid (HA) on the contralateral ear; the choice of HA for this purpose is therefore crucial. In recent years, the use of frequency transposition has gained a renewed interest in clinical practice. This type of processing records information from the high-frequency region and conveys it to a low-frequency region where there is still some residual hearing.

PURPOSE

To conduct an investigation and examine whether adults with unilateral CI derive benefits from a HA utilizing linear frequency transposition (LFT) on the contralateral ear.

RESEARCH DESIGN

A two-period, single-blind, repeated-measures crossover design was conducted to examine the combination of LFT in conjunction with a CI. Speech recognition tests were performed in quiet and in noise with LFT either activated or deactivated. The Speech, Spatial and Qualities of Hearing Questionnaire (SSQ) was used to measure subjective benefit.

STUDY SAMPLE

The participants were nine frequent bimodal users, five males and four females, with a moderate to profound high-frequency sensorineural hearing loss in the nonimplanted ear.

INTERVENTION

The current study was conducted using the Widex Mind440 power (m4-19) behind-the-ear HA. The participants acted as their own control in a total of seven conditions: (1) bimodal with own HA, (2) CI only, (3) own HA alone, (4) bimodal new HA LFT-off, (5) new HA LFT-off, (6) bimodal new HA LFT-on, and (7) new HA LFT-on.

DATA COLLECTION AND ANALYSIS

Monosyllabic words in quiet and the Swedish version of Hearing in Noise Test (HINT) were used as speech test materials. Stimuli were presented in sound field at a speech level of 65 dB sound pressure level (SPL) via a loudspeaker at a distance of 1 m from the participant in a sound-treated room. The SSQ was administered in each session evaluating the three bimodal conditions. SPSS software was used for statistical analyses. General linear model (GLM) analysis of variance for repeated measures was performed and followed with Bonferroni-adjusted post hoc pairwise comparisons.

RESULTS

Participants performed better with CI only than with HA alone, and the bimodal conditions were superior to the CI alone. No significant differences (p > .05) were observed when comparing the LFT-on with LFT-off regardless of whether the use of CI was included in the different listening conditions in objective and subjective measurements.

CONCLUSIONS

The results suggest an advantage for CI patients with a HA in the opposite ear, and that the LFT neither degraded nor enhanced speech performance in conjunction with a CI in quiet or in noise in comparison to when it was deactivated.

Increased concentrations of chlordane in adipose tissue from non-Hodgkin's lymphoma patients compared with controls without a malignant disease

Chlordane is a pesticide which is lipophilic, bioaccumulates, and may cause immunological impairment in exposed subjects. The aim of this study was to determine the concentrations of chlordane and its metabolites in cases with NHL and surgical controls without a malignant disease. Adipose tissue was obtained from the abdominal wall and analysis was performed using gas chromatograph coupled to mass spectrometer. The study included 27 NHL cases of the B-cell type and 17 controls. Significantly increased concentrations were found in NHL patients versus (vs) controls of trans-nonachlor, mean 98.9 vs 47.0, range 24.9-389 vs 16.3-88.2 ng/g lipid (p = 0.002), cis-nonachlor, mean 17.1 vs 7.4, range 4.1-68.3 vs 1.7-13.6 (p = 0.010), oxy-chlordane, mean 39.7 vs 24.5, range 8.5-144 vs 8.9-49.0, (p = 0.028) nonachlor III, mean 18.4 vs 8.7, range 6.3-67.6 vs 3.0-19.3 (p = 0.002) and sum of chlordanes, 180 vs 92.8, range 48.3-678 vs 37.0-164 ng/g lipid (p = 0.002). For cases with a concentration higher than the median for all subjects significantly increased odds ratios (OR) and 95% confidence intervals (CI) were calculated for trans-nonachlor (OR = 4.1, CI = 1.1-15), nonachlor LII (OR = 6.5, CI = 1.7-25), and sum of chlordanes (OR = 4.1, CI = 1.1-15); median concentrations were 61.2, 11.3, and 119 ng/g lipid, respectively.

Clonal chromosome-aberrations in fibrocystic breast disease-associated with increased risk of cancer

Short-term cultures of 29 samples of fibrocystic breast disease were cytogenetically analyzed. Clonal chromosome aberrations were found in six specimens, whereas the remaining 23 had a normal karyotype. Three of the abnormal samples displayed karyotypic anomalies previously associated with breast cancer, i.e., gain of Iq, trisomy 18 and cytogenetic multiclonality. Furthermore, all cytogenetically aberrant specimens had either proliferative disease without atypia or atypical hyperplasia, features of fibrocystic disease considered risk factors for subsequent breast cancer development. The cytogenetic similarities between breast carcinomas and proliferative fibrocystic breast disease add further support for classifying certain types of fibrocystic disease as a premalignant condition. Whether cytogenetically abnormal fibrocystic lesions are the ones that subsequently progress to cancer remains to be elucidated.

Improved gap repair cloning in yeast: treatment of the gapped vector with Taq DNA polymerase avoids vector self-ligation

Gap repair is a fast and efficient method for assembling recombinant DNA molecules in Saccharomyces cerevisiae. This method produces a circular DNA molecule by homologous recombination between two or more linear DNA fragments, one of which is typically a vector carrying replicative sequences and a selective marker. This technique avoids laborious and costly in vitro purification and ligation of DNA. The DNA repair machinery can also close and ligate the linear vector by mechanisms other than homologous recombination, resulting in an empty vector. The frequency of these unwanted events can be lowered by removing the 5'-phosphate groups using phosphatase, which is the standard method used for in vitro ligation. However, phosphatase treatment is less effective for gap repair cloning than for in vitro ligation, presumably due to the ability of the S. cerevisiae DNA repair machinery to efficiently repair the missing phosphate group to allow religation. We have developed a more efficient method to prevent vector religation, based on treatment of the vector fragment with Taq DNA polymerase and dATP. This procedure prevents vector recircularization almost completely, facilitating the screening for true recombinant clones.

Mindfulness-based stress reduction (MBSR) improves long-term mental fatigue after stroke or traumatic brain injury

OBJECTIVE

Patients who suffer from mental fatigue after a stroke or traumatic brain injury (TBI) have a drastically reduced capacity for work and for participating in social activities. Since no effective therapy exists, the aim was to implement a novel, non-pharmacological strategy aimed at improving the condition of these patients.

METHODS

This study tested a treatment with mindfulness-based stress reduction (MBSR). The results of the programme were evaluated using a self-assessment scale for mental fatigue and neuropsychological tests. Eighteen participants with stroke and 11 with TBI were included. All the subjects were well rehabilitated physically with no gross impairment to cognitive functions other than the symptom mental fatigue. Fifteen participants were randomized for inclusion in the MBSR programme for 8 weeks, while the other 14 served as controls and received no active treatment. Those who received no active treatment were offered MBSR during the next 8 weeks.

RESULTS

Statistically significant improvements were achieved in the primary end-point--the self-assessment for mental fatigue--and in the secondary end-point--neuropsychological tests; Digit Symbol-Coding and Trail Making Test.

CONCLUSION

The results from the present study show that MBSR may be a promising non-pharmacological treatment for mental fatigue after a stroke or TBI.