Maternal psychopathology and offspring mental health service utilization in adolescents without mental disorders: a national representative survey

European Child & Adolescent Psychiatry - We investigated whether maternal psychopathology predicts offspring mental health service utilization in adolescents without mental disorders. We used...     

Methotrexate preconditioning allows sufficient engraftment to confer drug resistance in mice transplanted with marrow expressing drug-resistant dihydrofolate reductase activity

Methotrexate (MTX) is an effective antitumor agent that has been demonstrated to be particularly useful in the treatment of hematopoietic neoplasms but causes substantial hematologic and gastrointestinal toxicity. We previously demonstrated that transplantation with transgenic marrow expressing drug-resistant dihydrofolate reductase (DHFR) into animals preconditioned by irradiation substantially protected recipient mice from the toxic side effects of methotrexate administration. Here we test the use of methotrexate itself as a preconditioning agent for engraftment of drug-resistant transgenic marrow, subsequently conferring drug resistance upon recipient animals. Administration of methotrexate beginning 1 or 2 weeks prior to or on the same day as transplantation with drug-resistant DHFR transgenic marrow did not allow sufficient engraftment to confer drug resistance to most unirradiated recipients. A small number of animals were curiously protected from lethal MTX toxicity but exhibited extremely low hematocrits and were not engrafted with stem cells, as indicated by low engraftment levels assessed in secondary transplant recipients. However, we subsequently found that MTX preconditioning allowed sufficient engraftment of DHFR transgenic marrow to confer drug resistance if MTX administration was withdrawn at the time of bone marrow transplantation (BMT) and withheld until 2 weeks post-transplant. Quantitative molecular analysis of primary and secondary recipients indicated a stem cell engraftment level of approximately 1%, consistent with previous studies demonstrating that a low level of DHFR transgenic cell engraftment was sufficient to confer drug resistance in recipient animals. We conclude that MTX can be used as a preconditioning agent for subsequent engraftment of hematopoietic stem cells, in this case conferring resistance to MTX.     

Hounsfield units as predictor for cage subsidence and loss of reduction: following posterior-anterior stabilization in thoracolumbar spine fractures

Study design

A retrospective, longitudinal cohort study.

Objective

The purpose of this study was to examine whether Hounsfield units (HUs), as an alternative bone mineral density measurement to dual-energy X-ray absorptiometry and quantitative computed tomography, which lead to additional radiation exposure for patients, has an effect on the maintenance of reduction in bisegmental Cobb angle (CA) and cage subsidence in patients who receive bisegmental spine stabilization after traumatic thoracolumbar spine fractures.

Methods

A total of 81 patients with a mean follow-up of 12 months were analyzed. CAs and cage subsidence were measured intraoperatively and at follow-up. HU was measured, and patients were subsequently assigned based on HU to three HU subgroups (group 1: HU?<?110 [poor bone quality (BQ)]; group 2: HU 180–110 [diminished BQ]; group 3: HU?>?180 [good BQ]).

Results

Following anterior stabilization, loss of reduction and cage subsidence differed between patients with poor and diminished BQ but not significantly, and both groups showed significantly more loss of reduction and cage subsidence than patients with good BQ.

Conclusion

BQ, estimated with HU, had significant effects on cage subsidence and loss of reduction. We recommend measuring HU before surgery and applying additional treatment strategies, such as polymethylmethacrylate augmentation of endplates or anterior plates, for patients with HU?<?180.

Graphical abstract

These slides can be retrieved under Electronic Supplementary Material.

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Online Reduction of Artifacts in EEG of Simultaneous EEG-fMRI Using Reference Layer Adaptive Filtering (RLAF)

Simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) allow us to study the active human brain from two perspectives concurrently. Signal processing based artifact reduction techniques are mandatory for this, however, to obtain reasonable EEG quality in simultaneous EEG-fMRI. Current artifact reduction techniques like average artifact subtraction (AAS), typically become less effective when artifact reduction has to be performed on-the-fly. We thus present and evaluate a new technique to improve EEG quality online. This technique adds up with online AAS and combines a prototype EEG-cap for reference recordings of artifacts, with online adaptive filtering and is named reference layer adaptive filtering (RLAF). We found online AAS?+?RLAF to be highly effective in improving EEG quality. Online AAS?+?RLAF outperformed online AAS and did so in particular online in terms of the chosen performance metrics, these being specifically alpha rhythm amplitude ratio between closed and opened eyes (3–45% improvement), signal-to-noise-ratio of visual evoked potentials (VEP) (25–63% improvement), and VEPs variability (16–44% improvement). Further, we found that EEG quality after online AAS?+?RLAF is occasionally even comparable with the offline variant of AAS at a 3T MRI scanner. In conclusion RLAF is a very effective add-on tool to enable high quality EEG in simultaneous EEG-fMRI experiments, even when online artifact reduction is necessary.