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OBJECTIVE: Endoscopic third ventriculostomy and choroid plexus cauterization (ETV+CPC) is a novel procedure for infant hydrocephalus that was developed in sub-Saharan Africa to mitigate the risks associated with permanent implanted shunt hardware. This study summarizes the hydrocephalus literature surrounding the ETV+CPC intraoperative abandonment rate, perioperative mortality rate, cerebrospinal fluid infection rate, and failure rate. METHODS: This systematic review and meta-analysis followed a prespecified protocol and abides by Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search strategy using MEDLINE, EMBASE, PsychInfo, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Scopus, and Web of Science was conducted from database inception to October 2019. Studies included controlled trials, cohort studies, and case-control studies of patients with hydrocephalus younger than 18 years of age treated with ETV+CPC. Pooled estimates were calculated using DerSimonian and Laird random-effects modeling, and the significance of subgroup analyses was tested using meta-regression. The quality of the pooled outcomes was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. RESULTS: After screening and reviewing 12,321 citations, the authors found 16 articles that met the inclusion criteria. The pooled estimate for the ETV+CPC failure rate was 0.44 (95% CI 0.37-0.51). Subgroup analysis by geographic income level showed statistical significance (p < 0.01), with lower-middle-income countries having a lower failure rate (0.32, 95% CI 0.28-0.36) than high-income countries (0.53, 95% CI 0.47-0.60). No difference in failure rate was found between hydrocephalus etiology (p = 0.09) or definition of failure (p = 0.24). The pooled estimate for perioperative mortality rate (n = 7 studies) was 0.001 (95% CI 0.00-0.004), the intraoperative abandonment rate (n = 5 studies) was 0.04 (95% CI 0.01-0.08), and the postoperative CSF infection rate (n = 5 studies) was 0.0004 (95% CI 0.00-0.003). All pooled outcomes were found to be low-quality evidence. CONCLUSIONS: This systematic review and meta-analysis provides the most comprehensive pooled estimate for the ETV+CPC failure rate to date and demonstrates, for the first time, a statistically significant difference in failure rate by geographic income level. It also provides the first reported pooled estimates for the risk of ETV+CPC perioperative mortality, intraoperative abandonment, and CSF infection. The low quality of this evidence highlights the need for further research to improve the understanding of these critical clinical outcomes and their relevant explanatory variables and thus to appreciate which patients may benefit most from an ETV+CPC. Systematic review registration no.: CRD42020160149 (https://www.crd.york.ac.uk/prospero/).
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Lodgepole pine (Pinus contorta) killed by mountain pine beetle (Dendroctonus ponderosae) (BLP) was compared with healthy lodgepole pine (HLP) for bioconversion to ethanol and high-value co-products. The BLP and HLP chips were pretreated using an ethanol organosolv process at a variety of severities. It was shown that the BLP was easier to pretreat and delignify than were the HLP chips. The resulting pretreated BLP substrate had a lower residual lignin, lower degree of polymerization of cellulose, lower cellulose crystallinity, smaller fiber size and thereby a better enzymatic hydrolysability than did the HLP substrates. However, under the same conditions, the BLP showed lower substrate yield and cellulose recovery than did the HLP, which likely resulted from the excessive hydrolysis and subsequent decomposition of the cellulose and hemicellulose during the pretreatment. The BLP wood yielded more ethanol organosolv lignin than was obtained with the HLP material. The HLP lignin had a lower molecular weight and narrower distribution than did the BLP lignin. It appears that the beetle killed LP is more receptive to organosolv pretreatment other than a slightly lower recovery of carbohydrates.
