35 research outputs found
Pediatric colloid cysts: a multinational, multicenter study. An IFNE-ISPN-ESPN collaboration
OBJECTIVE Colloid cysts (CCs) are rare at all ages, and particularly among children. The current literature on pediatric CC is limited, and often included in mixed adult/pediatric series. The goal of this multinational, multicenter study was to combine forces among centers and investigate the clinical course of pediatric CCs. METHODS A multinational, multicenter retrospective study was performed to attain a large sample size, focusing on CC diagnosis in patients younger than 18 years of age. Collected data included clinical presentation, radiological characteristics, treatment, and outcome. RESULTS One hundred thirty-four children with CCs were included. Patient age at diagnosis ranged from 2.4 to 18 years (mean 12.8 ± 3.4 years, median 13.2 years, interquartile range 10.3–15.4 years; 22% were \u3c 10 years of age). Twenty-two cases (16%) were diagnosed incidentally, including 48% of those younger than 10 years of age. Most of the other patients had symptoms related to increased intracranial pressure and hydrocephalus. The average follow-up duration for the entire group was 49.5 ± 45.8 months. Fifty-nine patients were initially followed, of whom 28 were eventually operated on at a mean of 19 ± 32 months later due to cyst growth, increasing hydrocephalus, and/or new symptoms. There was a clear correlation between larger cysts and symptomatology, acuteness of symptoms, hydrocephalus, and need for surgery. Older age was also associated with the need for surgery. One hundred three children (77%) underwent cyst resection, 60% using a purely endoscopic approach. There was 1 death related to acute hydrocephalus at presentation. Ten percent of operated patients had some form of complication, and 7.7% of operated cases required a shunt at some point during follow-up. Functional outcome was good; however, the need for immediate surgery was associated with educational limitations. Twenty operated cases (20%) experienced a recurrence of their CC at a mean of 38 ± 46 months after the primary surgery. The CC recurrence rate was 24% following endoscopic resection and 15% following open resections (p = 0.28). CONCLUSIONS CCs may present in all pediatric age groups, although most that are symptomatic present after the age of 10 years. Incidentally discovered cysts should be closely followed, as many may grow, leading to hydrocephalus and other new symptoms. Presentation of CC may be acute and may cause life-threatening conditions related to hydrocephalus, necessitating urgent treatment. The outcome of treated children with CCs is favorable
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.
In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field
Transition metal catalysis of acetals and pivalates: enantioselective and enantiospecific methods for C-C & C-B bond formation
Watson, Mary P.This dissertation focuses on the development of transition metal-catalyzed reactions of acetal and pivalate substrates. These new methods enable efficient synthesis of highly enantioenriched organic molecules. The first chapter discusses an enantioselective alkynylation of chromene acetals using copper (I) catalysts. In this method, we have observed wide substrate scope, and high enantioselectivities were observed especially with 4-aryl chromene acetals. Use of dilute conditions, BF 3 OEt2 as Lewis acid and Cy2 NMe as base are critical for achieving high enantioselectivities. In this chapter, a mechanism and stereochemical model are proposed that rationalize the observed substituent effects and enantioselectivities. This method demonstrates the advantage of using transition metal catalysis to facilitate reactions involving oxocarbenium ion intermediates. Chapter 2 discusses enantiospecific, nickel-catalyzed cross-couplings of benzylic pivalates with mild and functional group tolerant arylboroxines as cross-coupling partners. The diarylalkane and triarylmethane products formed were obtained in high yields and levels of stereochemical fidelity. The success of this method depends on the use of Ni(cod) 2 as catalyst and NaOMe as base. In this method, we have shown broad substrate scope and wide functional group tolerance. Chapter 3 discusses an enantiospecific, nickel-catalyzed cross-coupling of 1,3-disubstituted secondary allylic pivalates with mild and functional group tolerant arylboroxines. The 1,3-diaryl allyl products are obtained with high levels of stereochemical fidelity and yields. Excellent regioselectivity and E/Z selectivity are also observed in this method. A wide variety of functional groups are tolerated, and the utility of this method is demonstrated in the synthesis of the anti-inflammatory drug (S )-ketoprofen. Chapter 4 discusses an enantiospecific, nickel-catalyzed cross-coupling of 1,3-disubstituted secondary allylic pivalates and bis(pinacolato)diboron (B2 Pin2 ) to form ??-aryl allyl boronates in high yields and ee's. In this method, the absolute configuration of the allylboronate product depends on the ligand and the solvent used. Thus, either enantiomer of allyl boronate is available from the same enantiomer of pivalate starting material. The optimized conditions for obtaining both retention and inversion products are discussed.University of Delaware, Department of Chemistry and BiochemistryPh.D
Giant cerebral cavernous malformation causing raised intracranial pressure in an adult: Case report and review of literature
Giant cerebral cavernous malformations (GCCMs) are very rare malformations in adults, and they rarely present with raised intracranial pressure due to obstructive hydrocephalus. Around 20 cases of GCCMs have been reported in available literature. We report such a case, discuss and review the available literature regarding this eminently treatable group of vascular malformations
Transarticular screw fixation using neuronavigation: Technique
<b>Background:</b> Transarticular screw placement needs highly accurate imaging. We assess the efficacy and accuracy of C1-C2 transarticular screw fixation using neuronavigation and also cast a technical note on the procedure. <b> Materials and Methods:</b> This study included a total of nine patients who underwent transarticular screw fixation using the neuronavigation system. A total of 15 screws were placed. All patients underwent postoperative CT scan with 3-Dimensional (3-D) reconstruction to check for the accuracy of implantation. <b> Results:</b> One patient had encroachment of the transverse foramen but there was no vertebral artery injury. There were no clinical complications or adverse sequelae. <b> Conclusion:</b> Neuronavigation is extremely helpful in C1-C2 transarticular screw fixation and gives excellent accuracy