Endoscopic third ventriculostomy (ETV) for Chiari 1 malformation: a systematic review and meta-analysis.

Meta-analysis and systematic review. To understand the role of endoscopic third ventriculostomy (ETV) for the treatment of concurrent Chiari Malformation Type I (CMI) and hydrocephalus in adults. A literature search on PubMed and Medline with MeSH terms relating to ETV and CMI identified 155 articles between 1988 and 2024. After excluding pediatric cases and other CNS pathologies with associated CMI, 11 articles met inclusion criteria. The Newcastle-Ottawa Scale was identified to assess heterogeneity and risk of bias among the 11 studies analyzed in this systematic-review and meta-analyses compared pre- and post-operative outcomes to examine the use of ETV as a treatment modality for CMI with hydrocephalus. From the 11 included studies, 35 cases of concurrent CMI and hydrocephalus treated with ETV were identified. ETV provided a pooled rate of symptom resolution or improvement of 66%. Additionally, meta-analysis discovered the following pooled rates: a reduction of tonsillar descent in 94% of patients, decreased ventriculomegaly in 94%, and ETV patency in 99%. Syringomyelia, nausea, papilledema and cerebellar dysfunction did not have sufficient numbers for meaningful statistical analyses. However, in each of these categories, more than 85% of the symptoms or radiographic findings improved. This review summarizes the safety and efficacy of ETV for the concurrent management of acquired CMI with hydrocephalus. Specifically, ETV improves radiological outcomes of both ventriculomegaly and tonsillar descent as well as the most prevalent neurological symptom, headaches.

Socioeconomic characteristics and postoperative outcomes of patients undergoing prenatal vs. postnatal repair of myelomeningoceles.

PURPOSE: To investigate differences in sociodemographic characteristics and short-term outcomes between patients undergoing prenatal versus postnatal myelomeningocele repair. METHODS: Patients who underwent myelomeningocele repair at our institution were stratified based on prenatal or postnatal timing of repair. Baseline characteristics and outcomes were compared. Multivariate analysis was performed to identify whether prenatal repair was a predictor of outcomes independent of socioeconomic measures. RESULTS: 49 patients underwent postnatal repair, and 30 underwent prenatal repair. Patients who underwent prenatal repair were more likely to have private insurance (73.3% vs. 42.9%, p = 0.03) and live farther from the hospital where they received their repair (251.5 ± 447.4 vs. 72.5 ± 205.6 miles, p = 0.02). Patients who underwent prenatal repair had shorter hospital stays (14.3 ± 22.7 days vs. 25.3 ± 20.1 days, p = 0.03), fewer complications (13.8% vs. 42.9%, p = 0.01), fewer 30-day ED visits (0.0% vs. 34.0%, p < 0.001), lower CSF diversion rates (13.8% vs. 38.8%, p = 0.02), and better functional status at 3-months (13.3% vs. 57.1% delayed, p = 0.009), 6-months (20.0% vs. 56.7% delayed, p = 0.03), and 1-year (29.4% vs. 70.6% delayed, p = 0.007). On multivariate analysis, prenatal repair was an independent predictor of inpatient complication (OR(95%CI): 0.19(0.05-0.75), p = 0.02) and 3-month (OR(95%CI): 0.14(0.03-0.80) p = 0.03), 6-month (OR(95%CI): 0.12(0.02-0.73), p = 0.02), and 1-year (OR(95%CI): 0.19(0.05-0.80), p = 0.02) functional status. CONCLUSION: Prenatal repair for myelomeningocele is associated with better outcomes and developmental functional status. However, patients receiving prenatal closure are more likely to have private health insurance and live farther from the hospital, suggesting potential barriers to care.

Comparative Benefits and Risks Associated with Currently Authorized COVID-19 Vaccines.

This article provides a systematic assessment of the efficacy, risks, and methodological quality of evidence from five major publicly available vaccine trials. Results from Pfizer-BioNTech mRNA, Moderna-US NIH mRN-1273, AstraZeneca-Oxford ChAdOx1 nCov-19, Gamaleya GamCovidVac (Sputnik V), and Ad26.COV2.S Johnson & Johnson vaccines were included. Extracted benefits and risks data from each trial were summarized using the GRADE approach denoting the overall certainty of evidence along with relative and absolute effects. Relative risk reduction across all five vaccine trials ranged from 45% to 96%. Absolute risk reduction in symptomatic COVID-19 ranged from 6 to 17 per 1000 across trials. None of the vaccines were associated with a significant increase in serious adverse events compared to placebo. The overall certainty of evidence varied from low to moderate. All five vaccines are effective and safe, but suggest room for improvement in the conduct of large-scale vaccine trials. Certainty of evidence was downrated due to risk of bias, which can be mitigated by improving transparency and thoroughness in conduct and reporting of outcomes.

Investigating the Impact of Polymer Length, Attachment Site, and Charge on Enzymatic Activity and Stability of Cellulase.

The thermophilic cellulase Cel5a from Fervidobacterium nodosum (FnCel5a) was conjugated with neutral, cationic, and anionic polymers of increasing molecular weights. The enzymatic activity toward an anionic soluble cellulose derivative, thermal stability, and functional chemical stability of these bioconjugates were investigated. The results suggest that increasing polymer chain length for polymers compatible with the substrate enhances the positive impact of polymer conjugation on enzymatic activity. Activity enhancements of nearly 100% were observed for bioconjugates with N,N-dimethyl acrylamide (DMAm) and N,N-dimethyl acrylamide-2-(N,N-dimethylamino)ethyl methacrylate (DMAm/DMAEMA) due to proposed polymer-substrate compatibility enabled by potential noncovalent interactions. Double conjugation of two functionally distinct polymers to wild-type and mutated FnCel5a using two conjugation methods was achieved. These doubly conjugated bioconjugates exhibited similar thermal stability to the unmodified wild-type enzyme, although enzymatic activity initially gained from conjugation was lost, suggesting that chain length may be a better tool for bioconjugate activity modulation than double conjugation.

A laboratory and simulation platform to integrate individual life history traits and population dynamics.

Understanding populations is important because they are a fundamental level of biological organization. Individual traits such as aging and lifespan interact in complex ways to determine birth and death and thereby influence population dynamics. However, we lack a deep understanding of the relationships between individual traits and population dynamics. To address this challenge, we established a laboratory population using the model organism C. elegans and an individual-based computational simulation informed by measurements of real worms. The simulation realistically models individual worms and the behavior of the laboratory population. To elucidate the role of aging in population dynamics, we analyzed old age as a cause of death and showed, using computer simulations, that it was influenced by maximum lifespan, rate of adult culling, and progeny number/food stability. Notably, populations displayed a tipping point for aging as the primary cause of adult death. Our work establishes a conceptual framework that could be used for better understanding why certain animals die of old age in the wild.

Hydrolytically Stable Maleimide-End-Functionalized Polymers for Site-Specific Protein Conjugation.

Site-specific conjugation to cysteines of proteins often uses ester groups to link maleimide or alkene groups to polymers. However, the ester group is susceptible to hydrolysis, potentially losing the benefits gained through bioconjugation. Here, we present a simple conjugation strategy that utilizes the amide bond stability of traditional 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide coupling while introducing site specificity. Hydrolytically stable maleimide-end-functionalized polymers for site-specific conjugation to free cysteines of proteins were synthesized using reversible addition-fragmentation chain-transfer (RAFT) polymerization. The alpha terminus of the polymers was amidated with a furan-protected aminoethyl maleimide using carbodiimide-based chemistry. Finally, the maleimide was exposed by a retro Diels-Alder reaction to yield the maleimide group, allowing for thiol-maleimide click chemistry for bioconjugation. A thermophilic cellulase from Fervidobacterium nodosum (FnCel5a) was conjugated using various strategies, including random 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC)/N-hydroxysuccinimide (NHS) coupling, site-specific hydroxyethyl maleimide (HEMI) end-functionalized coupling, hydroxyethyl acrylate (HEA) end-functionalized coupling, and amidoethyl maleimide (AEMI) end-functionalized coupling. Only the polymers conjugated by EDC and AEMI remained conjugated a week after attachment. This indicates that hydrolytically stable amide-based maleimides are an important bioconjugation strategy for conjugates that require long-term stability, while esters are better suited for systems that require debonding of polymers over time.