A Bibliographic Analysis of the Most Cited Articles in Global Neurosurgery.

OBJECTIVE: Global neurosurgery is the practice of neurosurgery with the primary purpose of delivering timely, safe, and affordable neurosurgical care to all who need it. The aim of this study is to identify the most frequently cited articles in global neurosurgery through a bibliographic review to characterize articles and trends around this growing topic. METHODS: The top most-cited articles in global neurosurgery were determined by searching the Web of Science database using a priori search terms. Articles with at least 5 citations were selected, and there were no time period or language restrictions. The data were extracted from each included article and all characteristics were summarized. RESULTS: A total of 932 articles were identified using the search terms; 69 articles fulfilled inclusion criteria and 17 articles were selected that had more than 5 citations. The articles' number of citations ranged from 6 to 98 for the most-cited article. Authors from, or affiliated with, 14 countries contributed to the 17 articles, and the country that had the greatest representation was the United States. The main topic discussed was surgical capacity, the second topic was the treatment of different neurosurgical conditions, and volunteerism was the third topic. CONCLUSIONS: There is currently a deficit in both the amount of literature surrounding the topic of global neurosurgery and how much that literature is cited. Developing innovative ways to increase academic productivity within, or in collaboration with, low-middle income countries is essential to contribute to global neurosurgery.

Neuronal Calcium Sensor 1 is up-regulated in response to stress to promote cell survival and motility in cancer cells.

Changes in intracellular calcium (Ca2+ ) signaling can modulate cellular machinery required for cancer progression. Neuronal calcium sensor 1 (NCS1) is a ubiquitously expressed Ca2+ -binding protein that promotes tumor aggressiveness by enhancing cell survival and metastasis. However, the underlying mechanism by which NCS1 contributes to increased tumor aggressiveness has yet to be identified. In this study, we aimed to determine (a) whether NCS1 expression changes in response to external stimuli, (b) the importance of NCS1 for cell survival and migration, and (c) the cellular mechanism(s) through which NSC1 modulates these outcomes. We found that NCS1 abundance increases under conditions of stress, most prominently after stimulation with the pro-inflammatory cytokine tumor necrosis factor α, in a manner dependent on nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB). We found that NFκB signaling is activated in human breast cancer tissue, which was accompanied by an increase in NCS1 mRNA expression. Further exploration into the relevance of NCS1 in breast cancer progression showed that knockout of NCS1 (NCS1 KO) caused decreased cell survival and motility, increased baseline intracellular Ca2+ levels, and decreased inositol 1,4,5-trisphosphate-mediated Ca2+ responses. Protein kinase B (Akt) activity was decreased in NCS1 KO cells, which could be rescued by buffering intracellular Ca2+ . Conversely, Akt activity was increased in cells overexpressing NCS1 (NCS1 OE). We therefore conclude that NCS1 acts as cellular stress response protein up-regulated by stress-induced NFκB signaling and that NCS1 influences cell survival and motility through effects on Ca2+ signaling and Akt pathway activation.

[Design and Evaluation of a Clinical Investigator Training for Student-lead Prospective Multicentre Clinical Trials: a CHIR-Net SIGMA Research-based Learning Project]. / Design und Evaluation eines Prüf-Studierenden-Kurses für studentische prospektive Multicenterstudien ­ ein CHIR-Net-SIGMA-Projekt zum forschenden Lernen.

BACKGROUND: Scientific skills are not sufficiently taught during medical training, neither in medical school nor during postgraduate education. This results in a lack of clinician scientists. In order to counter this problem, the surgical study network (CHIR-Net) founded SIGMA (Student-initiated German Medical Audit). This paper describes the development, performance and evaluation of a Clinical Investigator Training (CIT) aiming to qualify students to autonomously conduct clinical trials. MATERIAL AND METHODS: Based on the Kern cycle, a curriculum was developed, composed of three parts: online tutorials, a workshop and a follow-up period. The educational objectives were defined according to Bloom's taxonomy of knowledge. The learning objectives were based on the requirements of the "Network of Coordinating Centers for Clinical Trials" and the German Medical Association as well as content relevant to clinical studies. A wide range of educational instruments and assessments were used. By including all relevant professional groups involved in clinical trials, an interconnected working environment for students was generated. The increase in knowledge was assessed by a multiple-choice pre/post exam. The satisfaction of participants was analysed by a 5-point Likert scale, on which 5 indicated full approval. RESULTS: The first SIGMA CIT was realised in 2018; the workshop took place in Heidelberg in February. Thirty-two medical students from thirteen different centres participated. On average, 53.8 ± 8.3% of questions were answered correctly in the pre-test, compared with 71.2 ± 7.2% in the post-test (p < 0.0001). The maximal individual improvement was 30%; the lowest difference compared to the pre-test was 5%. Subjective evaluation results were positive with an average result of 4.63 ± 0.34 on a 5-point Likert scale. CONCLUSION: It is feasible to teach medical students the fundamentals of clinical trials. A compact Clinical Investigator Training using modern principles of teaching is able to prepare students for an autonomous performance of clinical trials.

Laquinimod Supports Remyelination in Non-Supportive Environments.

Inflammatory demyelination, which is a characteristic of multiple sclerosis lesions, leads to acute functional deficits and, in the long term, to progressive axonal degeneration. While remyelination is believed to protect axons, the endogenous-regenerative processes are often incomplete or even completely fail in many multiple sclerosis patients. Although it is currently unknown why remyelination fails, recurrent demyelination of previously demyelinated white matter areas is one contributing factor. In this study, we investigated whether laquinimod, which has demonstrated protective effects in active multiple sclerosis patients, protects against recurrent demyelination. To address this, male mice were intoxicated with cuprizone for up to eight weeks and treated with either a vehicle solution or laquinimod at the beginning of week 5, where remyelination was ongoing. The brains were harvested and analyzed by immunohistochemistry. At the time-point of laquinimod treatment initiation, oligodendrocyte progenitor cells proliferated and maturated despite ongoing demyelination activity. In the following weeks, myelination recovered in the laquinimod- but not vehicle-treated mice, despite continued cuprizone intoxication. Myelin recovery was paralleled by less severe microgliosis and acute axonal injury. In this study, we were able to demonstrate that laquinimod, which has previously been shown to protect against cuprizone-induced oligodendrocyte degeneration, exerts protective effects during oligodendrocyte progenitor differentiation as well. By this mechanism, laquinimod allows remyelination in non-supportive environments. These results should encourage further clinical studies in progressive multiple sclerosis patients.

Neuronal calcium sensor 1 (NCS1) promotes motility and metastatic spread of breast cancer cells in vitro and in vivo.

Increased levels of the calcium-binding protein neuronal calcium sensor 1 (NCS1) predict an unfavorable patient outcome in several aggressive cancers, including breast and liver tumors. Previous studies suggest that NCS1 overexpression facilitates metastatic spread of these cancers. To investigate this hypothesis, we explored the effects of NCS1 overexpression on cell proliferation, survival, and migration patterns in vitro in 2- and 3-dimensional (2/3-D). Furthermore, we translated our results into an in vivo mouse xenograft model. Cell-based proliferation assays were used to demonstrate the effects of overexpression of NCS1 on growth rates. In vitro colony formation and wound healing experiments were performed and 3-D migration dynamics were studied using collagen gels. Nude mice were injected with breast cancer cells to monitor NCS1-dependent metastasis formation over time. We observed that increased NCS1 levels do not change cellular growth rates, but do significantly increase 2- and 3-D migration dynamics in vitro. Likewise, NCS1-overexpressing cells have an increased capacity to form distant metastases and demonstrate better survival and less necrosis in vivo. We found that NCS1 preferentially localizes to the leading edge of cells and overexpression increases the motility of cancer cells. Furthermore, this phenotype is correlated with an increased number of metastases in a xenograft model. These results lay the foundation for exploring the relevance of an NCS1-mediated pathway as a metastatic biomarker and as a target for pharmacologic interventions.-Apasu, J. E., Schuette, D., LaRanger, R., Steinle, J. A., Nguyen, L. D., Grosshans, H. K., Zhang, M., Cai, W. L., Yan, Q., Robert, M. E., Mak, M., Ehrlich, B. E. Neuronal calcium sensor 1 (NCS1) promotes motility and metastatic spread of breast cancer cells in vitro and in vivo.

Consideration of vocal fold position in unilateral vocal fold paralyses.

The objective of this study was to improve the evaluation of unilateral vocal fold paralyses (uVFP) by means of an area measurement of the glottic plane, which describes the position of the paralysed vocal fold. The area measurements were related to electromyographic findings and clinical outcome (recovery, voice quality). In 56 patients (33 women and 23 men), uVFP were confirmed by endolaryngeal electromyography (EMG) of the paralysed vocal fold and cricothyroid muscles (CT). The EMG response was classified on a 4-point scale (from 0 to 3). Vocal fold position was divided into 'paramedian' and 'intermediate' and additionally quantified by measurement of the glottic area. An 'area quotient' (AQ) was calculated and related to the EMG findings and clinical outcome. Voice qualities were objectified regarding their additive noise (breathiness) and irregularity (roughness) using the 'Göttingen Hoarseness Diagram'. The majority of uVFP was due to iatrogenic lesions. The AQ of classically graduated 'paramedian' and 'intermediate' vocal fold positions was significantly different but did not correlate with objective voice quality values. There were no significant correlations regarding EMG findings, duration or recovery from paralyses. Laryngeal EMG remains the gold standard for verifying uVFP. But EMG did not correlate significantly with AQ or functional outcome of uVFP. The measurement of an AQ is suitable for obtaining continuous data describing the position of paralysed vocal folds beyond the terms 'paramedian' or 'intermediate' and provides the basis for clinical evaluations of diagnostic tools and therapeutic interventions.